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+The Project Gutenberg EBook of The Diatomaceae of Philadelphia and Vicinity, by 
+Charles Sumner Boyer
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: The Diatomaceae of Philadelphia and Vicinity
+
+Author: Charles Sumner Boyer
+
+Release Date: January 3, 2014 [EBook #44569]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK DIATOMACEAE ***
+
+
+
+
+Produced by Charlene Taylor, Bryan Ness, Keith Edkins and
+the Online Distributed Proofreading Team at
+http://www.pgdp.net (This file was produced from images
+generously made available by The Internet Archive)
+
+
+
+
+
+Transcriber's note: Text enclosed by underscores is in italics (_italics_).
+      Page numbers enclosed by curly braces (example: {25}) have been
+      incorporated to facilitate the use of the Index.
+
+Images of the original pages are available through Internet Archive. See
+      https://archive.org/details/diatomaceofphi00boye
+
+       *       *       *       *       *
+
+[Illustration: DUCK POND, CORNER OF FOURTH AND MARKET STREETS (ABOUT 1700)]
+
+
+
+
+THE DIATOMACEÆ OF
+PHILADELPHIA AND VICINITY
+
+
+BY
+
+CHARLES S. BOYER, A.M., F.R.M.S.
+
+
+_ILLUSTRATED WITH SEVEN HUNDRED
+DRAWINGS BY THE AUTHOR_
+
+
+PRESS OF
+
+J. B. LIPPINCOTT COMPANY
+
+EAST WASHINGTON SQUARE PHILADELPHIA
+
+1916
+
+
+
+
+PREFACE
+
+
+The present contribution to the local flora is intended as an introduction
+to more extended research.
+
+The study is of advantage in relation to the life history of aquatic
+animals, the determination of ocean currents, as proved by polar
+discoveries, the investigation of geological strata where other fossil
+forms are absent, and the analysis of water supply; and, when we consider
+the universal distribution of diatomaceæ in the earth, the water and even
+in the air and the enormous deposits formed in past ages and still forming,
+we are able to realize the importance of a knowledge of these complicated
+forms and their function of purification.
+
+The absence of descriptive works of reference in available form in this
+country, the polyglot confusion of authorities abroad and the amount of
+time, patience and skill required in obtaining, preparing and examining
+specimens, render the study one of difficulty.
+
+The bibliography is omitted, as it is understood by those who possess the
+works of reference, and but few synonyms are given, having but little,
+except historical, value, especially when it is considered that modern
+investigators have no access to many of the earlier collections, when any
+of these exist.
+
+So far as the marine forms are concerned, it is probable that nearly all
+occurring north of Florida are here included, and the fresh-water species
+described represent a large proportion of those found east of the
+Alleghanies. All of the figures are drawn to the same scale, a
+magnification of eight hundred diameters, from specimens in my possession,
+nearly all of which were found in or near Philadelphia.
+
+If the work is of any value in inducing further investigation, I hope, in
+the words of Julien Deby, that "those who follow my advice will find in the
+study of these wonderful little organisms as much pleasure as I myself have
+found."
+
+  THE AUTHOR.
+
+
+
+
+{5}INTRODUCTION
+
+
+The Delaware River rises in the Western Catskill Mountains, flows southward
+for about three hundred and seventy-five miles, and expands into Delaware
+Bay about sixty miles from the sea. Its origin is among the Devonian and
+Carboniferous rocks, and in its course it passes through Silurian, Triassic
+and Cretaceous formations, finally reaching the Cambrian and Laurentian
+beds. It also drains regions of the glacial drift and beds which overlie
+overturned Miocene strata, and are sometimes mixed with them. From the
+mountains, nearly four thousand feet high, to the Bay, where the depth of
+water is not greater than seventy-five feet, the diatomaceous flora, from
+Alpine cascades to the salt marshes of New Jersey, contains a larger number
+of species than any other equal portion of the American coast.
+
+The city of Philadelphia, about one hundred miles from the sea, lies at the
+junction of the Schuylkill with the Delaware, and much of the land near the
+rivers, especially southward, is flat and low, composed of recent alluvial
+deposits. In the central districts the ground is high, the deep sub-soil
+being mostly a dry gravel resting upon gneiss and schist, although it is in
+part composed of a bluish clay which was probably laid down in the bed of
+the ancient river before the last period of the glacial drift. The blue
+clay was not all deposited at the same time, as in the lower strata many
+marine forms are found which do not occur in the upper layers. This is
+notably the case in a deposit obtained at Spreckel's Sugar Refinery and
+also at the east end of Walnut Street Bridge, where a layer of blue clay
+occurs which is overlain by glacial drift. In other parts of the city
+mixtures of blue clay with more recent deposits are found, including
+fresh-water forms from numerous creeks and rivulets which traversed what is
+now the city proper, and especially from the vicinity of Fourth and Market
+Streets, where there existed as late as the year 1700 a large pond known as
+the "Duck Pond" which was subject to tidal overflow from its outlet, Dock
+Creek. The river water at Philadelphia is not noticeably brackish, although
+the tide extends thirty miles above the city and, before the building of
+Fairmount Dam, to the Falls of the Schuylkill. At certain times, when the
+river is low, the influx of tide water is sufficient to produce an
+abundance of brackish water diatoms at Greenwich Point. The entire absence,
+however, at present, of many of the marine forms obtained in dredgings in
+the Delaware opposite the city, as at Smith's Island, now removed, and in
+certain well borings at Pavonia, Pensauken, Gloucester and other places in
+New Jersey, where the depth reached the old blue clay, indicates conditions
+quite different from those now prevalent. In the Bay itself comparatively
+few living species are found, at least in any abundance.
+
+In the study of local forms which follows, the district included may be
+considered as circumscribed by the circumference of a circle having a
+radius of one hundred miles from Philadelphia, containing the States of New
+Jersey and Delaware, the southeastern part of {6}Pennsylvania, a portion of
+Maryland on the south and extending eastward to New York Bay and Long
+Island Sound as far as New Rochelle.
+
+The greater number of fresh-water species described have been obtained from
+near the city along the Darby, Crum, Ridley and Brandywine Creeks and from
+various places in New Jersey, including the Pine Barren region of the
+southern part of the State. Numerous collections have been made in the
+Schuylkill and the various reservoirs and along the Wissahickon, "where an
+Alpine gorge in miniature of singular loveliness is to be found within the
+limits of a city." The fossil deposits are from well borings near Camden,
+N. J., and from excavations in various parts of the city.
+
+There appears to be no relation between the Miocene beds of the eastern
+coast and the deposits here described, all of which have been formed later
+than the glacial period or in an interval between two such periods.
+Apparently no diatoms grew during the glacial era, at least in sufficient
+abundance to leave any perceptible traces of their existence. An
+examination of glacial "flour" and clays from the Catskills shows an entire
+absence of these forms, and I have never found them in the milky flow from
+the glaciers of the Alps nor in the constantly muddy streams in certain of
+our Western States. The opacity of the water produces the same result as
+the absence of light in the deep lakes of New England, where diatoms are
+found only on the stalks or roots of water-plants near the shore, while in
+shallow ponds, such as the small lake near the summit of Mt. Lafayette, the
+growth is abundant. Certain species will grow wherever there are moisture,
+light and heat, but the greater number require the presence, in small
+amounts, of substances produced by the decay of animal and vegetable life.
+An abundance of diatoms in fresh water is usually an indication of its
+potability, while their entire absence in shallow water may be due to an
+excess of bacteria.
+
+The specimens from which the drawings are made have been collected by the
+author for many years; in addition to possessing an almost complete library
+on the subject, he has had the advantage of examining material obtained by
+the late Mr. Lewis Woolman and numerous slides furnished by a number of
+friends, including Mr. John A. Shulze, Mr. Frank J. Keeley and Mr. T.
+Chalkley Palmer, to whom I here take pleasure in expressing my thanks.
+
+The difficulties of the study are well stated by Agardh in the following
+extract from the preface to his Systema Algarum:
+
+"Because, indeed, in this respect, no one will wonder whether in the
+distinction of species and reference to synonyms we have, perchance,
+committed many errors. They have occurred and are bound to occur, partly
+from the fact that one is not permitted to see the original specimens of
+all authors; partly, because sometimes even the original specimens of these
+plants are erroneous; partly, because the figures and descriptions of
+authors are often lacking and imperfect....
+
+"There is added the difficulty of the study itself of these plants, their
+submerged habitat, the minuteness of their structure, the rarity of their
+fruit, the change in the dried {7}plant, the impossibility of culture, the
+fallacies of microscopical vision and the chaotic condition of Algology
+itself to-day."
+
+The words of Agardh, written in 1824, are almost as true to-day. The lack
+of authentic specimens, which we hope will be remedied in time by the
+collections of the Smithsonian Institute, numerous incorrectly labelled
+slides in amateur collections, the imperfections of figures copied and
+recopied, without regard to relative size or correct references, and the
+confusion in the attempts to harmonize different descriptions, deter the
+student at the outset. The remaining difficulties mentioned by Agardh add,
+however, to the remarkable interest these forms have always had, since no
+increase in optical perfection of the microscope serves to lessen the
+mystery of their structure and mode of growth.
+
+
+CLASSIFICATION
+
+The few species of diatoms first discovered were included by Lyngbye,
+Dillwyn, and others in the genus _Conferva_. In 1824, the species,
+increased to forty-eight, were separated by Agardh into eight genera
+distinguished partly by their mode of growth. But little change was made
+until Heiberg, in 1863, advocated the division into symmetrical and
+asymmetrical forms. Without entering upon a general review of the later
+classifications, including Pfitzer's and Petit's divisions according to the
+number and location of the chromatophores, or the arrangement of Prof. H.
+L. Smith, because of the presence or absence of a raphe, or that of
+Mereschkowsky into motile and immotile forms, the modification of all of
+these methods by Schuett is here adopted, varied in accordance with certain
+monographs which appear to offer advantage.
+
+It is customary, especially among writers who are familiar with other
+classes of plants, to decry any classification of diatoms according to the
+markings of their siliceous envelopes. As, however, one of the chief
+distinctions of the class is the possession of a more or less siliceous and
+indestructible frustule, and as the cell and its contents are never seen
+except within the valves, their variety forms the only available method of
+identification. The cell contents, owing to the difficulty of observing
+their living condition, their continued change, their lack of distinct
+variation and their entire absence in fossil forms, render their
+consideration as a complete method of classification an impossibility. If,
+however, the cell contents can be brought into relation with the markings
+of their siliceous envelope, it will be a consummation for which the future
+student of these complicated forms ought to be grateful. That this result
+is one to be expected may be inferred from the fact that the arrangement of
+protoplasmic masses in the interior of the cell is coincident in some cases
+with markings on the valve, and the character of the endochrome is assuming
+a certain value in accentuating the difference between such forms as
+_Pleurosigma_ and _Gyrosigma_, or in the resemblance between _Hantzschia_
+and _Nitzschia_, or between _Surirella_ and _Campylodiscus_. Mereschkowsky,
+however, states that it is necessary to be careful in "establishing the
+relationship between diatoms based on the resemblance of their
+chromatophores," {8}and further observes that in _Hantzschia amphioxys_,
+_Scoliotropis latestriata_ and _Achnanthes brevipes_, three widely
+separated forms, the chromatophores are essentially the same.
+
+In one of the earliest classifications of diatoms, the individual cell
+received less consideration than the nature of the filament or thallus in
+which many species occur in the first stages of their growth. Those,
+however, which exist in colonies at first are, sooner or later, broken up
+into separate frustules, either before or at the time of their maturity or
+previous to conjugation, while very many species are never seen except in a
+free state. The union of frustules, therefore, is of secondary importance
+and the group must be considered as filamentous or unicellular algæ. Their
+relation to other algæ is not well determined. Among the _Desmidiaceæ_, a
+family of the order _Conjugales_, of the class _Chlorophyceæ_, the cells
+are in many forms divided by a constriction into symmetrical halves. The
+Conjugales are starch forming, with walls of cellulose. In the Diatomaceæ
+the starch is replaced by oil globules, while the walls of cellulose are
+more or less filled with a deposit of silica. The Conjugales, however,
+reproduce by zygospores and usually contain pyrenoids, as may be seen in
+the parietal chromatophores of _Spirogyra_. In the class _Heterokontæ_ we
+have the reserve material in the form of oil, instead of starch, but there
+are no pyrenoids. To this class belongs the order _Confervaceæ_, in which
+the cells are unicellular or filamentous, and to which all of the
+Diatomaceæ were referred. While, therefore, Diatomaceæ have a close
+affinity to the Desmidiaceæ and to the Confervaceæ, the determination of
+their origin, one from another, or from a common ancestral type, appears to
+be a matter of conjecture.
+
+
+
+
+{9}MORPHOLOGY AND DEVELOPMENT
+
+
+THE CELL
+
+The cell membrane is composed of two usually equal parts, each of which
+consists of a valve and a girdle or zone formed of cellulose modified by
+silica deposited in an insoluble state from a very dilute aqueous solution.
+The valves are more siliceous and robust than the girdle. Both are in most
+species easily separable, or at least the bands of the girdle which may be
+more or less closely fastened to the valves have a motion over each other
+permitting the cell to enlarge at pleasure. The longitudinal diameter of
+the cell, or the distance between the centres of the two valves, will vary
+according to the convexity of the valve and the age of the frustule which
+may be often determined by the width or number of the girdle bands. These,
+owing to their diversity of form and arrangement, will be further described
+under the generic diagnoses.
+
+The siliceous cell-wall is covered on the outside by a layer of protoplasm
+called the coleoderm. This layer may be quite thin and evident only when
+treated with fuchsin or Bismarck brown, or it may be of considerable
+thickness. The cell contains the cytoplasma, protoplasm, cell-sap,
+endochrome, pyrenoids, oil globules and nucleus, together with certain
+other less understood bodies.
+
+The Cytoplasma is a thin skin of colorless plasma covering the entire inner
+surface of the cell. It is invisible in the living cell but is evident in
+plasmolysis. In long forms it is thickened at the ends and is condensed at
+the plasma bridge which frequently connects the two valves and divides the
+cell into two parts, each containing more or less protoplasm surrounding
+the vacuole in which are found the cell-sap and certain granules. In some
+forms, as Meloseira, the cytoplasma includes the entire mass of protoplasm.
+
+The Endochrome is seen in the form of one or more bands or plates, of a
+yellowish or brownish color, on the inner side of the valves or connective
+zone, or in granules or irregular masses, more or less numerous, on the
+inner walls, or sometimes grouped near the centre. It consists of a mixture
+of chlorophyll and diatomine which differ in their relative solubility in
+alcohol and in their spectroscopic analyses. The color varies from green to
+a chocolate brown in proportion to the amount of diatomine. So far as the
+function of the endochrome is concerned it does not appear to differ from
+that of ordinary chlorophyll, absorbing, under the influence of light, the
+carbon, and disengaging the oxygen of the carbonic anhydride in the water.
+Diatoms do not live in absolutely pure or non-aërated water. The individual
+plates or granules of the endochrome are called chromatophores. Their
+number and significance will be referred to in the description of genera.
+
+THE PYRENOIDS.--In the chromatophores of many species are found colorless,
+homogeneous bodies, strongly refractive, of various shapes, usually
+lenticular or fusiform, which are known as Pyrenoids (Schmitz). They are
+scarcely evident in the living cell, but are distinguished by the action of
+hæmatoxylin and other reagents. Flat forms occur in Surirella and
+Pleurosigma, lens forms in Pinnularia, Stauroneis, Synedra, Fragilaria and
+Nitzschia, while a spherical form is found in Cymbella cuspidata. The
+pyrenoids are always imbedded in the chromatophore. Their growth is by
+division. Schmitz considers them a part of the living chromatophore, and
+their substance as working material which in excess has become resolved
+into the nature of a crystal which its form sometimes resembles.
+Comparisons are made between them and crystalloids found in certain
+monocotyledons. The pyrenoid is evidently concerned in the formation of the
+chromatophore, or in its division. Much of the conjecture, however, is due
+to the behavior of pyrenoids in other plants.
+
+{10}OIL GLOBULES.--It has been established by Pfitzer that starch and
+sugar, as assimilation products, are replaced by oil in the cells of
+diatoms ("da bekannlich Staerke und Zucker bei den Bacillariaceen nicht
+nachzuweisen sind"). The oil drops are more or less numerous, of various
+sizes, and are found in the cytoplasma, the cell-sap, and sometimes the
+chromatophores. Mereschkowsky describes certain globules as elæoplasts,
+which he divides into four kinds according to their number and position.
+Whether all of these are oil globules is a question not yet determined.
+
+Other bodies, known as "Buetschli granules," or volutin, and described as
+"little blisters filled with a tolerably robust refractive substance," are
+considered by Lauterborn to be a nitrogen reserve store. They are found in
+the cytoplasma, or in the cell-sap, and can be fixed in picric acid and
+stained in methylene blue.
+
+NOTE.--For a discussion of the morphology of diatoms and a valuable résumé
+of the investigations of Buetschli, Karsten, Lauterborn, Mereschkowsky,
+Mueller, Pfitzer, Schuett, and others, the student is referred to "Der Bau
+der Diatomzelle," by Dr. Otto Heinzerling, in "Bibliotheca Botanica," 1908.
+
+
+CELL DIVISION
+
+The growth of diatoms follows the usual method of cell division as
+described by Sachs (Text Book of Botany, 2nd ed., p. 16): "The nucleus of a
+cell which is about to divide becomes broader, assuming the form of a
+biconcave lens, and its nucleolus breaks up into irregular granules which
+together with its other granular contents begin to form a nuclear disc in
+the equatorial plane. A delicate striation is now apparent in what is
+becoming the long axis of the nucleus, at right angles to the nuclear disc,
+and the characteristic nuclear spindle is gradually produced. The nuclear
+disc splits into two halves lying side by side, each of which travels to
+the corresponding pole of the nucleus; thus two nuclei are constituted
+which are connected by fibrillæ."
+
+The cell-wall and the chromatophore bands divide, each nucleus passes to
+the centre, and two new cells are formed. In the meantime, to permit of
+this division, the two siliceous valves separate, the girdle bands slipping
+over each other, and opposite the larger or enclosing valve a new valve is
+formed, the girdle band of which is seen later within the girdle of the
+mother valve. Opposite the smaller valve of the original cell and adjoining
+the new valve, another valve is formed which also produces a girdle within
+the girdle of the smaller valve. As a result of division we have,
+therefore, the valves of the original, or mother cell, the two new valves
+and four girdle bands. (Pl. 40, Figs. 18 and 19.)
+
+In the process of division, the continual formation of new valves, enclosed
+in the older girdle bands, will naturally cause a reduction in the size of
+the frustule. While this reduction, owing to the elasticity of the girdle,
+does not always occur, I believe, yet, in most cases, the diameter is so
+reduced that a rejuvenescence of growth is required. This is caused by the
+production of auxospores which may appear without conjugation. In this
+process, the beginning of which, in certain species, may be noticed by the
+increase in the size of the girdle as in reduplication, the two valves
+separate and within is formed a more or less spherical mass about twice the
+size of the original frustule and which forms on its circumference two
+large and often shapeless valves. These valves form others which assume the
+appearance of the original valves, but larger, and proceed to grow in the
+usual way. The reduction in size of the frustule seldom proceeds further
+than about half the size of the type form, so that, as a general rule, it
+may be stated that diatoms are not often smaller than half the larger size.
+
+
+REPRODUCTION
+
+The process of reproduction has been observed in many cases, but the
+conclusions reached are somewhat at variance with each other. The auxospore
+formation is simply a {11}method of rejuvenescence. When, however, the
+auxospores are thrown off from filamentous diatoms, it is probable that two
+may conjugate, their contents dividing each into two daughter cells which
+unite into two zygospores. The usual method is the union of two frustules,
+which, throwing off the old valves, coalesce into a single mass of
+protoplasm which produces an auxospore, sometimes called a sporangial
+frustule. It is stated that in some cases two frustules coalesce and
+produce two auxospores.
+
+The existence of spores in diatoms is a much-disputed point. While they
+have never been seen, the inference that they exist is very great, as
+otherwise it becomes difficult to understand the sudden growth of species
+in localities and under conditions that seem to preclude the actual
+presence of the living frustule. It is a matter of common observation that,
+in examining collections of living forms, minute frustules or brownish
+globules appear to resemble larger diatoms. In gatherings of Gomphonema,
+when many specimens are sessile on the same object, numerous intermediate
+sizes, varying from minute globules to the type, are seen, yet not
+positively demonstrable as the same.
+
+Conjugation, the formation of auxospores, and the actual process of cell
+division are seldom seen, as they occur during the night or at least in
+darkness. It is advisable in order to observe reduplication to obtain the
+material about midnight and place it in very dilute alcohol. In filamentous
+forms, however, the cell division is easily observed at any time in its
+various stages. By immersing in picric acid (saturated solution),
+transferring to very dilute alcohol which is gradually increased in
+strength, and then passing through oil of cloves and finally to the
+mounting medium, excellent preparations can be made. By staining with gold
+chloride alone the nucleus is made apparent without further treatment.
+
+
+EVOLUTION OF FORMS
+
+It may be assumed that diatoms originated in the sea; to deny this requires
+evidence of the existence of fresh-water species previous to the Miocene
+period which is entirely marine. In those subject to fluctuations of the
+waves, as pelagic diatoms, their existence appears to be contingent upon
+the methods by which the separate frustules can cohere. Various devices,
+including hooks, spiral bundles, horns and processes exuding threads of
+plasma, exist for holding together the frustules. When marine forms are
+found in quiet waters some of these devices, being no longer of any value,
+cease to grow, although free swimming diatoms are rare. They either occur
+in long chains or are stipitate or sessile. If it is further assumed that
+the fresh-water diatoms are found in greater abundance in later periods,
+the action of running streams makes necessary the provision of some means
+by which the species may continue to colonize. This may be recognized in
+the occurrence of linear forms chiefly in streams. Circular forms, such as
+Cyclotella which have no raphe, are found in quiet waters, such as pools or
+ditches, and never exist living in running streams. Those forms only would
+be able to live in water having a more or less swift current under one of
+three conditions: they must, as in Gomphonema, be adherent to surrounding
+objects by a stipe; or be enclosed in a gelatinous tube, as in
+Homoeocladia; or have an independent motion powerful enough to overcome the
+influence of the current. It is true that many forms with a raphe have no
+apparent motion. In the case of Mastogloia provision is made in a
+gelatinous cushion in which the frustules are preserved. In Cocconeis, with
+a true raphe in one valve only, in Epithemia, with a partial raphe, or in
+certain Eunotiæ with a trace of one, we find species evidently degenerate
+and parasitic. The long Synedræ, having only a median line, live in running
+streams, since they are attached at one end to other algae. Forms with a
+true raphe appear to be more highly developed, since they are able to seek
+locations favorable to growth. Given, therefore, the structure of the
+valve, the habitat may be inferred.
+
+
+{12}THE MOTION OF DIATOMS
+
+The erratic backward and forward movement of certain diatoms, especially
+those of the Naviculoid group, or the slow, rolling motion of Surirella,
+has been discussed in so many ways without definite conclusions that a
+brief statement will be sufficient. Osmosis, the amoeboid movement of the
+coleoderm, the protrusion of protoplasm or protoplasmic threads through the
+raphe, the existence of actual organs of locomotion or cilia, and the lack
+of synchronism in the chemical action occurring at the ends of the cell
+which is sometimes divided by the plasma bridge, have been offered in
+explanation. The chief objection to the theory of cyclosis appears to be
+that the resultant motion is so greatly in excess of the rotation of
+protoplasm in the cell. More or less motion is observed in various kinds of
+free cells, but the movement of diatoms is not evident in those without
+either a raphe or a keel upon which and apparently by which the phenomena
+are produced.
+
+Mr. T. Chalkley Palmer, in various articles in the Proceedings of the
+Delaware County Institute of Science, especially in Vols. 1 and 3, gives
+the results of exhaustive experiments. "Nothing, it would seem," he says,
+"could be more conclusive as to the essential sameness of the nature of
+motion in monads and diatoms, than the fact that both monads and diatoms
+require oxygen in order to perform motion, that they come to rest when
+oxygen becomes scarce, and that they resume their motion when oxygen is
+again supplied."
+
+He also thinks "that the living substance of the cell, more or less deeply
+overlaid with coleoderm substance of varying consistency, and itself
+assuming that degree of fluidity which best meets the requirements of the
+situation, permeates the raphes, circulates in the keels, or in some cases
+protrudes quite beyond the silica, and functions as the actual propulsive
+agent."
+
+
+THE FUNCTION OF DIATOMS
+
+Of all forms of vegetation, the Diatomaceæ are, perhaps, the most
+ubiquitous. Where-ever a sufficient amount of moisture, heat and light are
+found, they grow. It was during the Miocene period that they first
+appeared, and, as marine forms, reached their greatest development, both as
+to size and beauty of marking, while their prevalence throughout the world
+in enormous quantities has been often mentioned. The Miocene beds of
+Richmond and Maryland continued over the Cretaceous formations of New
+Jersey have outcropped in certain localities within our district, but are
+not considered in this discussion.
+
+The function of diatoms is not essentially different from that of other
+algæ in providing food for aquatic animals, such as Salpæ and oysters, but
+it is, however, in other respects that they are not only important but
+necessary factors in the preservation of life.
+
+ "Full nature swarms with life; one wondrous mass
+  Of animals, or atoms organized,
+  Waiting the vital breath, when parent heaven
+  Shall bid his spirit blow. The hoary fen,
+  In putrid streams, emits the living cloud
+  Of pestilence. Thro' subterranean cells
+  Where searching sunbeams scarce can find a way,
+  Earth animated heaves."
+
+I am not certain if Thomson fully understood the matter, but he has
+remarkably described the facts. When "the vital breath" of returning spring
+animates the earth, the "subterranean cells" of diatoms, the "atoms
+organized," through the liberation of vast quantities of oxygen,
+immediately begin the purification of the "putrid streams." Were these
+streams not so purified, the accumulation of animal and vegetable débris
+would eventually cause an enormous bacterial growth fatal to animal life.
+
+
+
+
+{13}DIATOMACEÆ
+
+
+Unicellular or filamentous. Cells either free, sessile, united in
+filaments, immersed in a gelatinous envelope or in fronds composed of
+branching tubes; microscopic, enclosed in a more or less siliceous envelope
+(frustule), composed of two parts (valves), usually connected by an
+intervening band (zone or girdle). Cell contents include yellowish or
+brownish chlorophyll-like bodies which occur in one or several bands
+(placcochromatic), or as variously distributed granular masses
+(coccochromatic) lining the inner walls. Growth by ordinary cell division
+or by auxospores; sexual multiplication by the formation of sporangia.
+Valves of two kinds: (_a_) Those in which the markings or parts are more or
+less concentric (Centricæ); (_b_) Those (Pennatæ) in which the parts are
+more or less symmetrically divided by a line (pseudoraphe) or by a cleft
+(raphe).
+
+
+
+CENTRICÆ
+
+Valves without a dividing line or cleft; markings more or less radiate;
+transverse section of frustule circular, polygonal, or elliptical,
+sometimes irregular.
+
+Divided into four groups:
+
+1. _Discoideæ._--Frustules (cells) discoid; valves without horns or
+elevations (sometimes with processes).
+
+2. _Solenoideæ._--Frustules with numerous girdle bands.
+
+3. _Biddulphioideæ._--Frustules box-like, _i. e._, with the longitudinal
+axis greater than in the Discoideæ. Valves with two or more angles,
+elevations or horns.
+
+4. _Rutilarioideæ._--Valves as if naviculoid, but with irregular or radial
+structure.
+
+Groups 2 and 4 are not included in our description. No. 2 contains plankton
+genera only, while No. 4 consists of genera not yet found in this locality.
+
+
+
+DISCOIDEÆ
+
+1. _Coscinodisceæ._--Valve not divided by rays or costæ into sectors;
+puncta sometimes radiate; ocelli or processes absent.
+
+2. _Actinodisceæ._--Valve with radial striæ divided into sectors: ocelli
+and processes absent.
+
+3. _Eupodisceæ._--Valve disc-shaped with mammiform processes or one or more
+ocelli.
+
+
+
+1. COSCINODISCEÆ
+
+(_a_) _Meloseirinæ._--Frustules short, in chains.
+
+(_b_) _Coscinodiscinæ._--Frustules disc form, usually single, rarely in
+short chains.
+
+
+
+(_a_) MELOSEIRINÆ
+
+1. _Meloseira._--Valve punctate, with a constriction or furrow between edge
+of valve and girdle.
+
+2. _Gaillonella._--Valve punctate, with a circular collar or crest near
+edge of valve.
+
+3. _Lysigonium._--Valve punctate, neither keeled nor constricted.
+
+4. _Hyalodiscus._--Valve punctate in the centre; border with decussating
+radial lines.
+
+5. _Stephanopyxis._--Border of valve with a crown of thorns; valve
+areolate.
+
+6. _Pyxidicula._--Valve areolate, with a border of spines.
+
+
+{14}MELOSEIRA AG. (1824), em. DE TONI (1892)
+
+(melos, a limb or member, and seira, a chain)
+
+Frustules globose, ellipsoidal or cylindrical, concatenate, closely joined
+together. Valve either simply punctate or punctate and areolate. A
+constriction of the cell-wall, forming a furrow between the edge of the
+valve and the girdle, is more or less evident.
+
+The genus Meloseira constituted by Agardh has been variously modified by
+Kuetzing, Thwaites, Wm. Smith, Van Heurck, De Toni, and others. In Systema
+Algarum Agardh included certain species of Conferva, of Lyngbye, Dillwyn
+and others, and limited his genus to frustules more or less globose (fila
+articulata ad genicula constricta), although in his Conspectus Criticus (p.
+64), he modifies the description (fila teretia articulata, articulis
+diametro æqualibus vel longioribus) to include M. varians. As, however,
+Lysigonium Link, Gaillonella Bory, and other genera enlarged by Ehrenberg
+and Kuetzing, came to be included under Meloseira, Thwaites suggested the
+division of the genus into two: Orthosira, in which the frustules are not
+convex at the ends and Aulacosira in which no central line is apparent but
+with two distinct sulci. Wm. Smith adopts the genus Orthosira but rejects
+Aulacosira, including all forms under the former genus and Meloseira,
+suggesting that differences "exist in the formation of the sporangia" of
+the two genera. M. varians and M. crenulata appear to form auxospores or
+sporangial frustules in different ways, as will be noticed hereafter.
+
+As, however, the present state of our knowledge is so limited and as much
+confusion would result in further changing the nomenclature, I shall adopt,
+for the most part, the division made by De Toni, separating Gaillonella and
+Lysigonium and employing the name Meloseira as emendated in Sylloge
+Algarum, although, as stated, it omits the species of Agardh. That a
+further division may be necessary is indicated by the differences existing
+between the Orthosira forms and the others.
+
+
+ANALYSIS OF SPECIES
+
+
+  Frustules cylindrical and lengthened:
+
+    Valves with two distinct furrows; granules small          distans
+
+    Valves with coarse granules                               granulata
+
+    Valves denticulate on the margin                          crenulata
+
+    Valves denticulate and constricted                        roeseana
+
+    Valves with row of large puncta on the girdle side        undulata
+
+  Frustules cylindrical and compressed:
+
+    Valves punctate and areolate                              sulcata
+
+The chromatophores consist of circular and compressed or irregular flat
+granules which lie along the wall of the cell.
+
+
+MELOSEIRA DISTANS (EHR.) KUETZ.
+
+Frustules cylindrical, slender, with two furrows, one on each side of the
+suture; valve in zone view with fine puncta in longitudinal rows; puncta in
+valve view scattered. L. 7-10 µ.
+
+_Meloseira nivalis_ Wm. Sm.
+
+_Coscinodiscus minor_ Wm. Sm.
+
+Fresh water. Fossil in New England deposits.
+
+Pl. 1, Figs. 8 and 9.
+
+NOTE.--In all species of Meloseira, as well as Gaillonella and Lysigonium,
+the frustules are so closely coherent that when the filaments are broken
+entire frustules are less frequently found than a union of two valves of
+contiguous frustules.
+
+
+{15}MELOSEIRA GRANULATA (EHR.) RALFS
+
+Frustules cylindrical, robust, 5-18 µ in diam., with large granules in
+longitudinal, sometimes spiral, lines, variable in size and arrangement in
+the same filament. Valve in valve view with scattered puncta. Variable in
+relative width and length, passing to M. crenulata.
+
+_Gaillonella granulata_ Ehr.
+
+_Orthosira punctata_ Wm. Sm.
+
+Fresh water. Fossil at Coldspring, L. I.
+
+Pl. 1, Fig. 10.
+
+
+MELOSEIRA CRENULATA (EHR.) KUETZ.
+
+Frustules cylindrical, with furrows on each side of the suture, 10-20 µ in
+diam.; puncta in longitudinal rows. Margins of valves denticulate at the
+junction of the frustules; valves with puncta scattered at the centre,
+radiate at the circumference.
+
+Common in fresh water; quite variable in size.
+
+_Gaillonella crenulata_ Ehr.
+
+_Orthosira orichalcea_ Wm. Sm. in part; not Conferva orichalcea. Mertens or
+Gaillonella aurichalcea Ehr. and Bailey.
+
+Pl. 1, Figs. 1 and 2.
+
+
+MELOSEIRA ROESEANA RAB.
+
+Frustules cylindrical, constricted toward each end, with coarse,
+longitudinal striæ; valve convex, striæ punctate, radiating, with several
+large granules at the centre. Connective zone with longitudinal rows of
+fine puncta. Diam. 12-45 µ.
+
+_Orthosira spinosa_ Grev.
+
+Fresh water. Media, Pa. (Palmer); not common.
+
+Pl. 1, Figs. 5 and 6.
+
+
+MELOSEIRA ROESEANA VAR. EPIDENDRON (EHR.) GRUN.
+
+Frustules denticulate at the margin; valve with coarse granules at the
+centre from which radiate lines of fine puncta.
+
+Wet rocks of the Wissahickon.
+
+Pl. 1, Figs. 3 and 4.
+
+
+MELOSEIRA UNDULATA (EHR.) KUETZ.
+
+Frustules single or in twos, usually broader than long, constricted near
+the margin. Valve with six to twelve internal projections forming with the
+outline of the constriction of the valve a polygonal figure within the
+circumference. Surface of the valve with radiating lines of puncta
+disappearing toward the centre, at which are numerous coarse puncta.
+
+_Meloseira gowenii_ A. Schmidt.
+
+Blue clay of Philadelphia, especially common at Twelfth and Market Sts.
+
+Pl. 1, Figs. 15, 16, 17.
+
+
+MELOSEIRA SULCATA KUETZ.
+
+Frustules quite robust, with diam. several times the length, deeply
+furrowed at the margin, areolate and punctate. Valve with radiating striæ
+disappearing toward the centre, and with a double row of cells near the
+margin, the outer one having the appearance of a crown of teeth.
+
+_Gaillonella sulcata_ Ehr.
+
+_Paralia sulcata_ (Ehr.) Cleve.
+
+_Paralia marina_ Heib.
+
+{16}Marine and brackish. Common in all parts of the world, and fossil in
+the Miocene. The Philadelphia form is the var. genuina Grun.
+
+Pl. 1, Figs. 11 and 12.
+
+In a gathering from Media of Meloseira crenulata (Palmer leg.), occasional
+filaments are noticed with much longer and narrower frustules which become
+enlarged in the middle and are seen to contain inner frustules in the
+process of still further division, as shown in Fig. 2, Pl. 38.
+
+Meloseira dickei Thwaites shows internal box-like cells placed one within
+the other, which were supposed by Thwaites to be a method of reproduction.
+Wm. Smith doubts this, but is unable to offer any explanation. In the
+present form the mode of reduplication is that usually found in filamentous
+forms, but in this case the presence of perfect frustules enclosing others
+in the process of still further division has been heretofore unfamiliar to
+me. The swelling in the middle appears to indicate that not all filamentous
+diatoms are reduced in size by subdivision. In outline the valve is like
+that of a "truncated cone," as described by Petit in referring to
+Gaillonella granulata var. bambusina Petit (Diat. Nouv. et Rares, Jour. de
+Micrographie, 1890).
+
+
+GAILLONELLA BORY DE ST. VINCENT (1823)
+
+(named after Gaillon, a botanist of Dieppe)
+
+Frustules ellipsoidal, united in long filaments, usually found in pairs;
+each valve is furnished with a circular collar or crest extending at right
+angles to the convex edge. Valve hyaline at the centre from near which
+radiate lines of fine puncta, 18-20 in 10 µ.
+
+NOTE.--The original names of both Meloseira and Gaillonella are retained,
+as there is no good reason for contracting the Greek diphthong in the
+first, and the second is the correct spelling.
+
+
+GAILLONELLA NUMMULOIDES (DILLW.) BORY
+
+Frustules as in the generic diagnosis. Diam. 30 µ.
+
+_Conferva nummuloides_ Dillwyn (Brit. Confervæ, p. 45, Sup. Pl. B).
+
+_Meloseira nummuloides_ Ag.
+
+Heiberg and O'Meara assign this species to _Lysigonium moniliforme_
+(Muell.) Link, which is not keeled. While Dillwyn's and Lyngbye's figures
+do not show the keel, it is probable from their descriptions that the
+angular outline produced by the keel was noticed.
+
+Marine or brackish. Coast of New Jersey; Hudson River (Bail.).
+
+Pl. 1, Figs. 13 and 14.
+
+_Gaillonella moniliformis_ of Bailey is this form, as he describes it as
+having "two minute projections of the delicate transverse ridges seen near
+the ends of the two globules belonging to a joint." (Amer. Jour. Science,
+1842, p. 89, Pl. 2, Fig. 3.)
+
+
+LYSIGONIUM LINK (1820)
+
+(luo, to loose, and gonu, a joint)
+
+Frustules globose, concatenate; valve simply punctate.
+
+
+LYSIGONIUM MONILIFORME (MUELL.) LINK
+
+Frustules usually in twos, not keeled; valve with puncta in longitudinal
+lines, the puncta of the enveloping zone larger and in transverse rows. L.
+25-40 µ (De Toni).
+
+_Conferva moniliformis_ Mueller (1783).
+
+{17}_Conferva nummuloides_ Eng. Bot. pl., 2287, not Dillwyn.
+
+_Meloseira borreri_ Grev.
+
+_Lysigonium nummuloides_ (Lyngb., Kuetz.) O'Meara = _Gaillonella
+nummuloides_ (Dillw.) Bory. See O'Meara, p. 248.
+
+Marine and brackish. Long Island Sound and coast of New Jersey.
+
+Pl. 1, Fig. 7.
+
+
+LYSIGONIUM VARIANS (AG.) DE TONI
+
+Frustules cylindrical, in long filaments, slightly constricted on each side
+of the suture; puncta in oblique rows in zone view. Valves 15-35 µ in diam.
+(De Toni), sub-plane, with fine puncta in lines radiating from the centre.
+Under medium magnification the frustules appear smooth. Very variable in
+size.
+
+_Meloseira varians_ Ag.
+
+Fresh water. Common in ditches and springs.
+
+Pl. 1, Figs. 18 and 19.
+
+
+HYALODISCUS EHR. (1845)
+
+(hyalos, transparent, and discus, a disc)
+
+Frustules spheroidal; valve with a flattened, irregularly punctate
+umbilicus from which proceed radiating or decussating lines of fine puncta.
+
+
+ANALYSIS OF SPECIES
+
+
+  Valves divided into sectors                                 stelliger
+
+  Valves not divided but interrupted by short dark lines at
+    intervals                                                 radiatus
+
+  Valves with very fine puncta                                scoticus
+
+
+HYALODISCUS STELLIGER BAIL.
+
+Valve with puncta in oblique decussating rows which, by reason of the
+difference in obliquity, form numerous sectors. Umbilicus irregular, with
+scattered, coarse puncta. Margin wide, striated.
+
+_Podosira maculata_ Wm. Sm.
+
+Blue clay. Not common.
+
+Pl. 1, Fig. 22.
+
+
+HYALODISCUS RADIATUS VAR. ARCTICA GRUN.
+
+Valve with radiating puncta from a rather small umbilicus, the rays
+interspersed with short, dark lines, having the appearance of spines, at
+irregular intervals. Margin broad, striated.
+
+_Pyxidicula radiata_ O'Meara.
+
+The Philadelphia form corresponds exactly to Grunow's variety which has
+closer puncta than the type form.
+
+Blue clay. Rather rare.
+
+Pl. 1, Fig. 21.
+
+
+{18}HYALODISCUS SCOTICUS (KUETZ.) GRUN.
+
+Valve small, with puncta about 24 in 10 µ, appearing hyaline.
+
+De Toni remarks that it resembles a small form of H. subtilis which occurs
+north and south of our limits and is yet likely to be recorded.
+
+_Cyclotella scotica_ Kuetz.
+
+_Podosira hormoides_ Wm. Sm.
+
+Blue clay. Not rare.
+
+Pl. 1, Fig. 20.
+
+Endochrome in the form of four flaps or patches bound together about a
+common pyrenoid. In H. subtilis numerous rod-shaped chromatophores lie in a
+row and are not bound in the centre (Mereschkowsky).
+
+
+STEPHANOPYXIS EHR. (1844) em. GRUN. (1884)
+
+(stephanos, a crown, and pyxis, a kind of vase or box)
+
+Frustules ellipsoidal, concatenate; valves tumid, of unequal convexity,
+coarsely areolate, the cells in rows parallel to the longitudinal axis, not
+radiate, with stray spines or teeth placed concentrically more or less near
+the margin.
+
+According to Karsten the chromatophores are round or angular discs which
+lie near the connective zone.
+
+
+STEPHANOPYXIS TURRIS (GREV.) RALFS
+
+Valve cylindrical, with a crown of stout spines less than the diameter of
+the valve near the margin. Cells hexagonal, about 2 in 10 µ, sometimes
+punctate. The valve having the greater convexity has the larger spines,
+though usually less of them.
+
+_Creswellia turris_ Grev. (Gregory, Diat. of the Clyde, T. R. S. E., vol.
+21, part 4, p. 66.)
+
+_Stephanopyxis appendiculata_ Ehr.?
+
+Creswellia is incorrectly based, as stated by Ralfs, on the concatenation
+of the valves which was not noticed by Ehrenberg in the fossil forms. It
+had been suggested by Kuetzing in Systema Algarum (p. 126).
+
+Blue clay. Port Penn and Smith's Island.
+
+Pl. 2, Figs. 1 and 2.
+
+
+STEPHANOPYXIS CORONA (EHR.) GRUN.
+
+Valve larger than in turris, sub-globose, coarsely areolate cells, 4-5 in
+10 µ. One valve furnished with a crown of teeth shaped like the letter T
+and united at the top into a ring above the margin of the valve; the other
+valve with long spines more or less concentrically arranged.
+
+Blue clay. Not common. Fossil in the Nottingham deposit.
+
+Pl. 2, Fig. 3.
+
+NOTE.--The diatomaceous deposit, so often called "Bermuda" or "Bermuda
+tripoli," especially by foreign writers, is in reality the Miocene stratum
+extending for miles along the Patuxent River near the village of
+Nottingham, Md. The author is perfectly familiar with the location, having
+made large collections there. The mistake in the name is due to the fact
+that Prof. Bailey received material from Mr. Tuomey marked "Bermuda
+Hundred," which is located near Petersburg, Va. Attempts have been made to
+find material there and while there is an earth containing Miocene diatoms
+at Petersburg, it does not exactly correspond to the material sent to
+Ehrenberg by Bailey, who was in doubt as to the locality. The Bermuda
+Islands are of coral formation and have no deposits of diatomaceous earth.
+
+
+{19}PYXIDICULA EHR. (1833)
+
+(dim. of pyxis, a box)
+
+Frustules globular, solitary or in short fasciæ. Valve more or less
+hemispherical, areolate, destitute of spines.
+
+
+PYXIDICULA CRUCIATA EHR.
+
+Valve hemispherical, with large, hexagonal cells. An inner stratum is
+finely punctate.
+
+Blue clay. Walnut St. Bridge. Rare.
+
+Pl. 38, Fig. 8.
+
+This form is not usually described as having punctate areolæ, but it does
+not apparently differ from other forms of Pyxidicula of Ehrenberg as
+described by Kuetzing (Species Algarum, pp. 21-23), including _P.
+areolata_. In fact, it differs from Stephanopyxis, which is also sometimes
+punctate, only in the absence of spines. In fossil deposits the absence of
+an easily detached stratum is not significant. The difference, except in
+size, between it and _P. mediterranea_ Grun. (V. H. S., Pl. 95, Figs. 15
+and 16), I am unable to determine.
+
+Although many species of Meloseira are fresh-water, the habitat of the
+group Meloseirinæ is, in general, marine. It more nearly coincides in
+structure and development with other algæ not diatomaceous, the siliceous
+envelope constituting its most distinctive feature. As we proceed in the
+classification, the structure both of the frustule and contents becomes
+more complicated.
+
+
+
+(_b_) COSCINODISCINÆ
+
+1. _Cyclotella._--Valve with two concentric divisions of different
+structure, one a wide border and the other a central surface.
+
+2. _Coscinodiscus._--Valve areolate or punctate, with a narrow border of
+the same structure.
+
+
+CYCLOTELLA KUETZ. (1833)
+
+(cyclos, a circle)
+
+Frustules single or geminate, cylindrical, short, in zone view rectangular
+or with undulating sides. Valve usually with smooth or punctate striæ,
+centre sometimes bullose, smooth, or with granules scattered or radiating.
+
+Chromatophores numerous along the valves (Pfitzer).
+
+
+CYCLOTELLA STRIATA (KUETZ.) GRUN.
+
+Valve 30-80 µ in diam., with coarse striæ, 7-12 in 10 µ, centre coarsely
+punctate and bullose.
+
+_Coscinodiscus striatus_ Kuetz.
+
+_Cyclotella dallasiana_ Wm. Sm.
+
+Common in the blue clay.
+
+Pl. 2, Fig. 9.
+
+
+CYCLOTELLA MENEGHINIANA KUETZ.
+
+Frustule in zone view rectangular, undulated; valve, 10-20 µ in diam.,
+marginal striæ robust and transversely punctate, centre radiately punctate.
+
+_Cyclotella kuetzingiana_ Wm. Sm. (not Thwaites).
+
+Crum Creek.
+
+Pl. 2, Fig. 8.
+
+
+{20}CYCLOTELLA MENEGHINIANA, VAR. STELLIGERA CL. AND GRUN.
+
+Differs from the type in the coarse radiating lines at the centre.
+
+Broomall Lake, Media.
+
+Pl. 2, Fig. 4.
+
+
+CYCLOTELLA MENEGHINIANA, VAR. STELLULIFERA CL. AND GRUN.
+
+As in type but with the central rays granulate.
+
+Broomall Lake, Media.
+
+Pl. 2, Fig. 12.
+
+
+CYCLOTELLA STYLORUM (BR.?) V. H.
+
+Margin striated, the alternate striæ thickened near the border, producing
+an appearance of subquadrate cells. Centre faintly granulate, the outer
+border of which is encircled by 10-12 puncta, each of which is surrounded
+by a small hyaline space.
+
+Blue clay. Rare.
+
+Van Heurck gives this form doubtfully as a variety of _striata_, while De
+Toni makes it synonymous with it. Van Heurck's figure is not that of
+Brightwell, but as the specimen above described is, I believe, exactly the
+same as Van Heurck's, I retain his name.
+
+Pl. 2, Fig. 10.
+
+
+CYCLOTELLA COMTA (EHR.) KUETZ.
+
+Valve with marginal striæ well marked, each third or fourth costa more
+robust than the others. Central part finely striated, the striæ punctate,
+radiating.
+
+Fresh water.
+
+Pl. 2, Fig. 7.
+
+The form here figured is probably the variety _radiosa_ Grun. and is from a
+New England specimen. It is quite likely to occur in this locality.
+
+
+CYCLOTELLA OPERCULATA (AG.) KUETZ.
+
+Frustules in zone view undulated. Angles rounded. Marginal costæ
+alternating with minute spines; centre nearly smooth, depressed, convex or
+flexuose.
+
+Fresh water.
+
+Pl. 2, Figs. 5 and 6.
+
+The figure is drawn from a specimen from Boston, Mass., H. L. Smith Type
+Slide No. 107, marked equivalent to _C. minutula_ Wm. Sm.
+
+
+CYCLOTELLA ANTIQUA WM. SM.
+
+Marginal costæ alternating with thick puncta; centre finely granulate with
+subtriangular elevations. Frustules in zone view rectangular.
+
+Blue clay.
+
+Pl. 2, Fig. 11.
+
+The form corresponds to the original specimens of Wm. Smith in the deposit
+of Stavenger, Norway.
+
+The genus Cyclotella comprises about seventy specific names, many of which
+may be referred to other genera, while some of Ehrenberg's are incapable of
+verification on account of the small size of the figures and the lack of
+sufficient description. About half of the forms are marine. The fresh-water
+species are usually found living in more or less stagnant water or in pools
+contaminated with drainage, being an exception to the general rule that
+diatoms are more abundant in water free from deleterious matter.
+
+
+{21}COSCINODISCUS EHR. (1838)
+
+(coscinon, a sieve, and discus)
+
+Frustules solitary, cylindrical, compressed; valve circular or elliptical;
+surface flat or sometimes convex near the border; markings more or less
+angular, radiating, sometimes fasciculate; border usually well defined.
+Central space, if present, hyaline, sometimes surrounded with a rosette of
+large cells.
+
+Chromatophores round, angular or irregular discs usually without pyrenoids
+(Karsten).
+
+Rattray's classification is here followed, so far as it refers to our
+species.
+
+_Excentrici._--Valves circular; central space absent; markings angular, in
+oblique, decussating rows.
+
+_Lineati._--Central space absent; markings angular, oblique decussating
+rows straight.
+
+_Fasciculati._--Markings fasciculate, or sometimes only near the border.
+
+_Radiati._--Markings rounded or angular, more or less radiate.
+
+_Elaborati._--Valves elliptical, markings rounded.
+
+
+EXCENTRICI
+
+COSCINODISCUS EXCENTRICUS EHR.
+
+Valve with a hyaline excentric space from which proceed, usually in six
+directions, rows of polygonal markings decreasing toward the narrow,
+coarsely striated border, the rows appearing convex toward the centre.
+Apiculi at unequal distances apart. Quite variable in size.
+
+Common in the blue clay and along the coast.
+
+Pl. 2, Figs. 14 and 20.
+
+Fig. 20 is probably var. _perpusilla_ Grun. (Diat. Fr. Jos. L., Pl. 4 (D),
+Fig. 7).
+
+
+LINEATI
+
+COSCINODISCUS LINEATUS EHR.
+
+Valve circular, markings hexagonal, cells in parallel rows. Border narrow,
+cellular.
+
+Blue clay and Atlantic coast. Not common.
+
+Pl. 3, Fig. 8.
+
+
+FASCICULATI
+
+COSCINODISCUS NITIDUS GREG.
+
+Valve flat, markings rounded, distant, radiate, decreasing toward the
+border which is coarsely striate. Quite variable in size and in the
+distance between the markings.
+
+Blue clay and Atlantic coast. Common.
+
+Pl. 2, Fig. 18.
+
+
+COSCINODISCUS NITIDULUS GRUN.
+
+Valve usually not quite circular; markings smaller than in nitidus and
+fasciculate near the border.
+
+Blue clay.
+
+Pl. 2, Fig. 19.
+
+Various intermediate forms between nitidus and nitidulus occur.
+
+
+COSCINODISCUS SUBTILIS EHR.
+
+Markings polygonal, irregular at the centre, but forming numerous fasciculi
+radiating {22}toward the border, the rows parallel to the central row of
+each fasciculus. Border narrow with fine striæ; apiculi often present
+between the fasciculi.
+
+Blue clay and along the coast. Very common in the water supply of
+Philadelphia and Camden, where the diameter seldom exceeds 40 µ and the
+markings on the semi-radius are 10 in 10 µ.
+
+Pl. 2, Fig. 17.
+
+
+COSCINODISCUS DENARIUS SCHMIDT
+
+Markings larger than in C. subtilis, equal, forming usually ten fasciculi,
+each beginning near the semi-radius and containing ten parallel rows of
+granules.
+
+Common in the blue clay and sparingly along the coast.
+
+Pl. 2, Fig. 13.
+
+Forms are found intermediate between C. subtilis and C. denarius, as shown
+in Fig. 15.
+
+
+COSCINODISCUS POLYACANTHUS GRUN.
+
+Markings angular, 10 in 10 µ, decreasing toward the border, fasciculate.
+Apiculi large, twelve or more, usually inserted at the middle of each
+fasciculus, and extending into the interior of the cell. The apiculi in
+outline resemble the heads of horse-shoe nails, and are seen with
+difficulty except when the valve is examined from the inner side. Border
+narrow, striated. Diam. 70 µ.
+
+Pensauken, N. J., artesian well.
+
+Pl. 38, Fig. 5.
+
+Rattray's description of _C. polyacanthus_ var. _intermedia_ Grun., from
+Cape Wankarema, Siberia, gives the diam. as 60 µ, and there are about 7
+markings by actual count in 10 µ in Grunow's figure (Diat. Fr. Jos. Land,
+Pl. 3 (C), Fig. 25). The apiculi are more numerous, but there appears to be
+little doubt of the general similarity. The Philadelphia form is abundant
+in the Pensauken well deposit at a depth of 33 ft. The apiculi become quite
+distinct in slides stained with silver nitrate by Mr. F. J. Keeley; they
+are distinct from small apiculi sometimes evident between the fasciculi.
+The specimens in the Pensauken deposit are mingled with other forms which
+cannot be distinguished from _C. subtilis_. Whether the two are identical,
+I am unable to determine. Rattray (Rev. Cos., p. 47) refers to H. L.
+Smith's Type Slide No. 100, from rice-field mud, Savannah, Ga., as _C.
+subtilis_. In Smith's slide, in my possession, a number of the forms show
+faint outlines of the large apiculi and are otherwise exactly like C.
+polyacanthus.
+
+
+RADIATI
+
+COSCINODISCUS VELATUS EHR.
+
+Markings angular, decreasing slightly toward the coarsely striated border,
+covered with fine puncta.
+
+Blue clay.
+
+Pl. 3, Fig. 2.
+
+
+COSCINODISCUS MARGINATUS EHR.
+
+Markings rounded, large, decreasing toward the broad border, which is
+coarsely marked with distant striæ. The cells are punctate.
+
+Common in the blue clay.
+
+Pl. 3, Fig. 9.
+
+In the fossil forms the puncta are not evident, hence the species is
+usually described as not punctate.
+
+
+{23}COSCINODISCUS RADIATUS EHR.
+
+Markings polygonal, slightly decreasing toward the border where they are
+much smaller; border well marked, striate. Quite variable in size.
+
+Common in the blue clay and along the coast.
+
+Pl. 3, Fig. 11. Fig. 1 is probably a smaller form.
+
+
+COSCINODISCUS SUBAULACODISCOIDALIS RATTR.
+
+Markings small, decreasing toward the border in somewhat fasciculate rows.
+About one-third the distance from the border are five (Rattray finds six)
+well-marked apiculi somewhat resembling those of Aulacodiscus. Border
+narrow, hyaline.
+
+Rare in the lower stratum of the blue clay.
+
+Pl. 3, Fig. 4.
+
+
+COSCINODISCUS ARGUS EHR.
+
+Markings angular with central dots, increasing from the centre toward the
+border, where they are smaller.
+
+Blue clay.
+
+Pl. 3, Fig. 7 (a small form).
+
+
+COSCINODISCUS BIANGULATUS SCHMIDT
+
+Central space and rosette absent, markings large, angular, not punctate,
+with large central papillæ, decreasing toward the border. Border wide,
+coarsely marked with rows of granules, and with two indentations on the
+inner side distant from each other about two-thirds of the diameter.
+
+Blue clay.
+
+Pl. 3, Fig. 3.
+
+Distinguished from Coscinodiscus asteromphalus var. omphalantha Grun.,
+which also has two constrictions, by the absence of punctate markings.
+
+
+COSCINODISCUS ASTEROMPHALUS EHR.
+
+Central space small, surrounded by a rosette of large polygonal cells from
+which radiate hexagonal cells, increasing about half way toward the border
+and then slightly decreasing. Cells punctate.
+
+Blue clay.
+
+Pl. 2, Fig. 16; Pl. 40, Fig. 12.
+
+
+COSCINODISCUS ASTEROMPHALUS VAR. OMPHALANTHA (EHR.) GRUN.
+
+Central space absent, rosette evident. Markings 2½ in 10 µ, somewhat
+smaller near the rosette and decreasing near the border, which is
+constricted in two places, as in C. biangulatus.
+
+Blue clay.
+
+Pl. 38, Fig. 10.
+
+
+COSCINODISCUS OCULUS-IRIDIS EHR.
+
+Central space and rosette distinct; markings polygonal, not punctate, with
+large papillæ, smaller near the rosette, increasing toward the semi-radius,
+and then decreasing to the striated border which is comparatively narrow.
+
+Blue clay and Atlantic coast.
+
+Pl. 3, Fig. 10.
+
+
+{24}ELABORATI
+
+COSCINODISCUS LEWISIANUS GREV.
+
+Valves elliptical, major axis a little more than twice the minor. From a
+point, usually near one side, radiate rows of granules in lines nearly
+parallel to the major axis. Border broad, with distinct striæ.
+
+Great Sedge Island, N. J. (artesian well), and in outcrops later than the
+Miocene, where it is usually found.
+
+Pl. 3, Fig. 5.
+
+
+
+2. ACTINODISCEÆ
+
+ACTINOPTYCHINÆ
+
+Valves divided into sectors alternately elevated and depressed.
+
+(1) _Actinoptychus._--Sectors plane.
+
+(2) _Polymyxus._--Sectors convex.
+
+
+ACTINOPTYCHUS EHR. (1839) em. V. H. (1890)
+
+(actis, a ray, and ptyx, a fold)
+
+Frustule cylindrical, less in length than the diameter, in zone view
+undulated. Valve divided into six or more sectors alternately raised and
+depressed, areolate and punctate, varying in the alternate divisions. The
+areolation is confined to the outer layer of the valve while the punctation
+is usually on an inner valve often found detached. Processes on the border,
+three or more. Umbilicus circular or angular, hyaline.
+
+
+ANALYSIS OF SPECIES
+
+
+  Sectors, six                                                undulatus
+
+  Sectors, eight or more, cellular                            heliopelta
+
+  Sectors, fourteen, punctate                                 vulgaris
+
+
+ACTINOPTYCHUS UNDULATUS (KUETZ.) RALFS
+
+Valve areolate and punctate in quincunx, divided into six equal sectors,
+alternately elevated or depressed, their areolations appearing different.
+Margin well defined. Umbilicus smooth, hexagonal. Processes three,
+sometimes six, inserted within the margin of each alternate division. Very
+variable in size and appearance.
+
+This is the Actinocyclus of Bailey, figured and described in Amer. Jour.
+Science, 1842, p. 93, Pl. 2, Fig. 11, but not named. Kuetzing describes and
+names it and refers to Bailey.
+
+_Actinoptychus omphalopelta_ Ehr.
+
+_Actinoptychus cellulosa_ Ehr., H. L. Smith Sp. Typ., 384.
+
+Quite common in marine and brackish water and in the blue clay.
+
+Pl. 4, Figs. 1, 2, 4 and 6.
+
+
+ACTINOPTYCHUS VULGARIS VAR. INTERRUPTA N. VAR.
+
+Valve with fourteen sectors, the alternate ones divided by a smooth
+lanceolate space for about one-half the radius, forming with the smooth,
+circular umbilicus a seven pointed star. The sectors thus divided have
+coarser puncta in quincunx than the other sectors, ending in a smooth area
+near the margin, and also larger black puncta scattered from the centre to
+the semi-radius.
+
+Near A. vulgaris var. neogradensis Pant.
+
+Blue clay. Not common.
+
+Pl. 4, Fig. 5.
+
+
+{25}ACTINOPTYCHUS HELIOPELTA GRUN. VAR.?
+
+Valve circular, sectors, eight, umbilicus circular, without rays; border
+wide, cellular, with distinct rays. Inserted at a distance within the inner
+edge of the border are large processes, one on each of four alternate
+sectors, and two on each of the others. The sectors are cellulate and
+punctate.
+
+Near A. heliopelta var. versicolor Brun., which, however, in the specimen
+in my collection from Atlantic City (artesian well), has a greater number
+of processes and they are situated on the edge of the border.
+
+Outcrop at Buckshutem, N. J. Rare.
+
+Pl. 4, Fig. 3.
+
+It has been quite well determined, I think, that the typical forms of A.
+heliopelta occur at the base of the Miocene. At Rock Hall, Md., on the
+eastern shore of Chesapeake Bay, at a depth of from 21 to 130 ft., and at
+Wildwood, N. J., at a depth of from 78 to 179 ft., diatomaceous beds occur
+considered by Mr. Lewis Woolman (Geol. Surv. of N. J., 1898, pp. 116-121)
+"as synchronous in age," the former being deposited in the Delaware River
+Delta and the latter in the Chesapeake in post-miocene times. In each of
+these beds a small form of A. heliopelta is rarely found. The material at
+Buckshutem is post-miocene, and the form here figured shows a marked
+variation from the Miocene species and a gradual approach toward A.
+undulatus.
+
+
+POLYMYXUS L. W. BAIL. (1855)
+
+Valve circular, usually divided into fourteen sectors which are on the same
+plane at the centre, but the alternate ones are elevated into mammillated
+projections terminated by small processes on the margin. Zone view
+rectangular with undulations subconical, terminated by the processes.
+
+
+POLYMYXUS CORONALIS L. W. BAIL.
+
+Central space hyaline, rounded or slightly stellate, from which radiate
+rows of fine puncta in quincunx, shown in the figure only on the alternate
+elevations, the depressed interspaces being out of focus. The mammillæ are
+stated by Bailey to vary from six to ten.
+
+Very rare in the blue clay (Walnut St. Bridge). Occurs also in the Wildwood
+deposit (Bull. Torrey Bot. Club, 1895, p. 261).
+
+Pl. 4, Fig. 7, and Pl. 5, Fig. 2.
+
+
+
+3. EUPODISCEÆ
+
+_Aulacodiscinæ._--Valves with mammiform elevations near the border
+surmounted by nipple-like processes.
+
+
+AULACODISCUS--THE ONLY GENUS AS ABOVE
+
+_Eupodiscinæ._--Valves with ocelli.
+
+(1) _Actinocyclus._--Valve with one small ocellus; striæ radial.
+
+(2) _Eupodiscus._--Valve with one or more ocelli; striæ not radial.
+
+(3) _Auliscus._--Valve with large, elevated ocelli. Central area hyaline.
+Markings granular and costate.
+
+(4) _Pseudauliscus._--Valve with radiating granules. No central space.
+
+
+{26}AULACODISCUS EHR. (1844) em. RATTR. (1888)
+
+(aulax, a furrow, and discus)
+
+Valve usually circular, plane or with an elevated zone, frequently inflated
+beneath the processes; central space irregular or rounded, sometimes
+absent; markings granular, radial, sometimes in a reticulum.
+
+The genus comprises more than one hundred species most of which are fossil,
+and is represented in this locality by a single form, _A. argus_, included
+by Rattray in his section "Retiformes," distinguished by the presence of a
+reticulum.
+
+
+AULACODISCUS ARGUS (EHR.) SCHMIDT
+
+Frustule in zone view elliptical. Valve circular, 125-190 µ in diam.,
+closely covered with two kinds of markings, one, a mesh of large,
+radiating, angular cells, the outer plate, and the other, radiating rows of
+circular granules with hyaline spaces intervening and closer near the
+border, forming the inner plate which can occasionally be seen detached.
+Central space absent. The walls of the angular cells are crossed with fine
+lines and are probably composed of granules compressed so closely as to
+produce partial opacity, the depth of which depends in a measure not only
+on the superposition of the two plates, but on the relative closeness and
+thickness of the cell-walls. In a fully-developed specimen the effect is to
+produce more or less triangular cells containing three or four granules. In
+some cases the opacity is so great as to render detail invisible.
+
+In the figure the valve is supposed to be divided into three sectors,
+illustrating at "a" the lower plate, at "c" the combination of the upper
+and lower plates, and in the other sector the cellular mesh of the upper
+plate. Processes, usually three, quite robust and inserted at from
+one-fourth to one-fifth the length of the radius from the border which is
+striated on the inner side. A form with four processes is found in the
+lower blue clay.
+
+_Tripodiscus argus_ Ehr.
+
+_Eupodiscus argus_ (Ehr.) Wm. Sm.
+
+Not uncommon in the blue clay.
+
+Pl. 4, Fig. 8.
+
+
+ACTINOCYCLUS EHR. (1837)
+
+(actis, a ray, and cyclos)
+
+Valve circular or elliptical; surface flat at the centre, sloping toward
+the border. Central space usually evident, rounded or irregular. Markings
+rounded, granular, punctiform, in radial, or nearly radial, rows, sometimes
+fasciculate. A nodule, more or less evident, is found near the border which
+is usually striate.
+
+Chromatophores round discs or granules.
+
+
+ANALYSIS OF SPECIES
+
+
+  Valve circular, rows radial, hyaline lines at the border    barkleyi
+
+  Valve circular, rows fasciculate                            moniliformis
+
+  Valve elliptical                                            ellipticus
+
+The nodule is generally supposed to be a thickening of the cell-wall, and,
+in the opinion of Rattray, a projection outward, but "whether there may not
+be at the same time a slight inward protuberance is difficult to
+determine," though, as a rule, he seems to "think there is not."
+
+
+{27}ACTINOCYCLUS BARKLEYI VAR. AGGREGATA RATTR.
+
+Surface flat from centre to semi-radius. Central space irregular, sometimes
+with a few scattered granules. Markings round with central dots distinct,
+about 7 at the centre, decreasing in straight radial rows to 12 in 10 µ at
+the border, where they form moniliform striæ. Border narrow with striæ
+about 16 in 10 µ. Hyaline interspaces at the origin of the shorter rows,
+but not at equal intervals. At the border, linear hyaline spaces occur at
+somewhat irregular intervals between the moniliform striæ owing to the
+termination of certain radial rows before they reach the circumference.
+Nodule small, from one-seventh to one-fourth the radius from the border.
+
+According to Rattray the distinction between A. ralfsii and A. barkleyi is
+partly in the absence of the zone arrangement of the hyaline spaces in the
+latter, and to the slight differences in the number of granules. The
+variety aggregata differs from the type form of barkleyi mainly in the
+distance of the nodule from the border. I have specimens from the blue clay
+material at Walnut St. Bridge, and from Smith's Island, in which the
+distance from the border in one case is, as stated above, quite different
+from that in the other. In specimens from Morris Cove, Conn., the locality
+referred to by Rattray, variations occur.
+
+Blue clay.
+
+Pl. 6, Fig. 1.
+
+In the figure the subulate hyaline spaces at the border are, in some
+instances, wider than usual.
+
+
+ACTINOCYCLUS MONILIFORMIS RALFS
+
+Surface flat, from centre to about five-sixths of the radius. Central space
+rounded, with one or more granules. Markings, 8 in 10 µ, round, in radial
+rows, fasciculate, the oblique transverse rows irregular, very slightly
+decreasing until near the edge of the flattened zone, and then suddenly
+decreasing and appearing as decussating lines oblique to the border.
+Apiculi distinct, interfasciculate within the border. Nodule quite evident,
+surrounded by a rather wide irregular hyaline space on the margin of the
+flattened zone in the middle of the fasciculus. Border wide, with striæ
+about 20 in 10 µ.
+
+Blue clay. Port Penn. Not common.
+
+Pl. 6, Fig. 2.
+
+Equivalent to Actinocyclus ehrenbergii, H. L. S. Type Slide 10.
+
+In a valve from Port Penn, Delaware Bay, two nodules occur nearly opposite
+each other.
+
+
+ACTINOCYCLUS ELLIPTICUS VAR. DELAWARENSIS N. VAR.
+
+Valve rhombic-elliptical. Markings somewhat angular, 6 in 10 µ at the
+centre where they are sub-concentric, thence decreasing in lines radiating
+more or less toward the border, where they suddenly become punctiform,
+striæ about 20 in 10 µ. Border equal to one-fifth the radius. A nodule is
+found on the inner side of the border. Apiculi apparently absent.
+
+The markings are larger than in the Richmond forms which are associated by
+Rattray with Actinocyclus ellipticus Grun. The form corresponds closely to
+Witt's Cestodiscus ovalis var.? (Witt, Polierschief. von
+Archangelsk-Kurojedowo, Pl. 8, Fig. 2), except as to the border. It does
+not answer to Van Heurck's figure or any other.
+
+Blue clay. Very rare.
+
+Pl. 3, Fig. 6.
+
+
+{28}EUPODISCUS EHR. (1844)
+
+(eu, well, pous, a foot, and discus)
+
+Valve circular, 45-117 µ in diam. (De Toni). Central space absent, surface
+plane with angular cells. At the border short, circular processes or
+ocelli.
+
+
+EUPODISCUS RADIATUS BAIL.
+
+Valve with radiating hexagonal cells, sometimes slightly curved toward the
+large ocelli inserted near the border which are hyaline at the centre.
+Border wide, coarsely striate.
+
+The number of ocelli heretofore recorded is four. Specimens with five
+processes are found in the artesian well at St. Augustine, Fla., and in
+material at Twelfth and Brandywine Sts. Mr. Hugo Bilgram has discovered
+valves with three and six ocelli.
+
+Not common in the blue clay, but abundant along the southern coast of the
+Atlantic states and the Gulf of Mexico.
+
+Not Eupodiscus radiatus Wm. Sm, which is Biddulphia smithii (Ralfs) V. H.
+
+Pl. 5, Fig. 3.
+
+
+AULISCUS EHR. (1843)
+
+(aulax, a furrow, referring to the grooves in certain species, according to
+De Toni, but preferably from auliscos, a small reed, referring to the
+processes?)
+
+Frustule cylindrical; zone with longitudinal rows of fine puncta. Valve
+circular or elliptical, plane except near the processes; central area
+hyaline, usually circular. Markings of two kinds, granules radiating or
+scattered and radiating, costate lines, prominent or indistinct. Processes,
+two or three, large, short, cylindrical, with hyaline surface, near the
+ends of the major axis in a line oblique to it.
+
+Auliscus is divided by Rattray into fourteen sections, defined chiefly by
+the character and arrangement of the markings. About eighty species are
+described, but as many of the forms are fossil, occuring in the Miocene of
+California, Oamaru and elsewhere, and as so few species are found in this
+locality, I shall refer but briefly to this division.
+
+
+  _Striolati._--No transverse median areas, striæ
+    inconspicuous                                             punctatus
+
+  _Lineolati._--Markings distinct, pruinose, interrupted      pruinosus
+
+  _Costati._--Transverse median areas usually distinct,       sculptus
+     markings continuous, costate                             cælatus
+
+AULISCUS PUNCTATUS BAIL.
+
+Valve broadly elliptical, or suborbicular, covered with delicate
+interrupted striæ radiating in sinuous lines to the circumference, more
+evident on the transverse median area; puncta 3 in 10 µ, grouped into a
+rounded area on each side of the median line, elsewhere scattered. Central
+space rounded, processes two, large, suborbicular.
+
+Port Penn, Delaware River. Rare.
+
+Pl. 5, Fig. 6.
+
+
+AULISCUS PRUINOSUS BAIL.
+
+Valve elliptical, with distinct, interrupted, pruinose, irregular markings
+diverging in curved lines toward the circumference in the median part and
+converging toward the processes, interspersed with numerous darker markings
+having the appearance of apiculi. Central space nearly circular, sometimes
+with several granules. Processes large near the ends of the major axis and
+not oblique to it, or scarcely so, the edges with a crenulate border.
+
+Blue clay. Rather rare.
+
+Pl. 5, Fig. 8.
+
+
+{29}AULISCUS SCULPTUS (WM. SM.) RALFS
+
+Valve elliptical or subcircular, median areas distinct, rounded,
+circumscribed by coarse distant costæ radiating near the border where they
+are more evident, and converging toward the processes. Central space
+rounded, sometimes indefinite. Processes, two, circular.
+
+Typical specimens show wide, coarse, distant costæ, but, in some cases, the
+median areas are indistinctly outlined.
+
+Blue clay.
+
+Pl. 5, Fig. 5.
+
+
+AULISCUS CÆLATUS BAIL.
+
+Valve elliptical or subcircular, with radiating costæ, more evident around
+the median areas and at the border, converging toward the processes, with
+intermediate punctate radiating lines. Central space rounded or irregular.
+Processes circular.
+
+A. sculptus has coarser costæ and the interspaces are hyaline, or
+apparently so, while in A. cælatus the punctate striæ between the costæ are
+more evident.
+
+Blue clay. Not uncommon.
+
+Pl. 5, Fig. 4.
+
+Fig. 7 is a small, indefinite form intermediate between A. sculptus and A.
+cælatus. The numerous variations in this genus make it difficult to
+satisfactorily differentiate the species. The size of the four above
+described varies from 40 to 150 µ.
+
+
+PSEUDAULISCUS A. S. (1875) AND LEUDUGER-FORTMOREL (1879)
+
+Valve circular or subcircular, nearly flat or depressed at the centre.
+Central space not evident. Processes circular, with narrow border, near the
+circumference. Border narrow, striated. Markings granular, radiating,
+sometimes interspersed with striæ and apiculi.
+
+Differs from Auliscus chiefly in the absence of a central space and costæ.
+
+
+PSEUDAULISCUS RADIATUS (BAIL.) RATTR.
+
+Valve circular, or nearly so, flat. Central area with scattered granules
+radiating and increasing in size outward in diverging rows toward the
+border which is coarsely striated. Processes, two, circular. Two small
+apiculi are inserted at about one-fifth the radius from the border near the
+ends of the minor axis.
+
+Blue clay. Rare.
+
+Pl. 5, Fig. 9.
+
+The apiculi are not always figured. They appear in a number of specimens
+from the Miocene of Maryland, Atlantic City, Harvey Cedars and Newbern.
+
+
+PSEUDAULISCUS SPINOSUS (CHRISTIAN) RATTR.
+
+Valve subcircular or slightly quadrangular, depressed at the centre and
+rising to an elevated zone near the border, the two zones separated by a
+distinct line. The inner zone indistinctly reticulate with fine puncta
+radiating from the centre and apiculi at intervals. The outer zone with
+smaller apiculi surrounding the inner zone and with intermingled rows of
+fine puncta and interrupted diverging striæ. Near each end of the minor
+axis is a rather long, robust spine inserted at one-fourth the radius from
+the border which is narrow and striated. Processes circular, close to the
+circumference.
+
+_Auliscus spinosus_ Christian.
+
+Blue clay. Rare.
+
+Pl. 5, Fig. 10.
+
+The genus is named by Schmidt, described by Leuduger-Fortmorel and
+emendated by Rattray.
+
+
+
+{30}BIDDULPHIOIDEÆ
+
+BIDDULPHIEÆ
+
+(_a_) _Triceratiinæ._--Frustule cylindrical or prismatic, with three or
+more sides.
+
+(_b_) _Biddulphiinæ._--Frustule cylindroid; valve with ends elevated into
+round processes or long horns.
+
+(_c_) _Anauleæ._--Valve elliptical, lunate or triangular, with internal
+septa.
+
+(_d_) _Euodieæ._--Frustule cuneate in zone view; valve lunate.
+
+
+
+(_a_) TRICERATIINÆ
+
+(1) _Ditylum._--Frustule imperfectly siliceous. Zone with numerous
+divisions. Valve with central spine.
+
+(2) _Trinacria._--Processes with sharp spines.
+
+
+DITYLUM BAIL. (1861)
+
+(dis, two, and tyle, a swelling, referring to the outline of the frustule)
+
+Frustule quadrangular, convex at the ends. Valve triangular, with
+undulating sides, the angles ending in a sharp point surmounted by a
+bristle. Surface of valve convex at centre from which projects a long stout
+spine.
+
+
+DITYLUM INTRICATUM (WEST) GRUN.
+
+Valve with the angles separated from the central part by lines imitating
+septa. Surface with radiating lines of fine puncta.
+
+Blue clay. Rare.
+
+Pl. 6, Fig. 4.
+
+Detached valves only have been found in the blue clay. The form is regarded
+as but slightly siliceous and, therefore, the zone or girdle not being
+found in the fossil deposits, I am unable to illustrate it from material in
+the vicinity. On Plate 38, Figs. 6 and 7, I have sketched the zone and
+valve views of specimens found recently at Vera Cruz and labelled by H. L.
+Smith Triceratum intricatum West. I can find no difference between the
+recent and fossil forms of the valves. The zone is covered with fine puncta
+in quincunx, not visible under ordinary illumination.
+
+The form as figured in Plate 6 corresponds to the figure of Lithodesmium
+undulatum Ehr. in Van Heurck, and West, in describing the Triceratium
+undulatum Wm. Sm. (figured as T. striolatum), thought that his T.
+intricatum was distinct from Ehrenberg's form on the ground that the latter
+came from the "Bermuda" (Nottingham) earth and must be strongly siliceous.
+Lithodesmium is characterized by the envelopment of the frustules by a
+cellular membrane which does not appear, evidently, in Ditylum. D.
+brightwellii is distinguished by its crown of spines on the margin;
+otherwise it closely resembles D. intricatum.
+
+
+TRINACRIA HEIB. (1863)
+
+(treis, three, and acra, a point)
+
+Valve triangular, angles elevated into spines. Cells at the margin large.
+
+
+TRINACRIA PILEOLUS (EHR.) GRUN.
+
+Valve with concave sides. Surface concave with unequal punctiform and
+scattered markings with central dots. Cells at the margin large, rounded.
+At the angles, which vary in elevation, a few puncta are seen.
+
+_Triceratium pileolus_ Ehr.
+
+Blue clay. Rare.
+
+Pl. 6, Fig. 9.
+
+
+
+{31}(_b_) BIDDULPHIINÆ
+
+BIDDULPHIA GRAY (1831) em. VAN HEURCK (1885)
+
+(a genus, constituted from Conferva biddulphiana of the English Botany,
+named after a Miss Biddulph)
+
+Frustule prismatic or subcylindrical, concatenate, filamentous, or in
+zig-zag, or, as usually found, free. Zone well developed. Valve triangular,
+polygonal, elliptic or subcircular, convex, more or less elevated at the
+angles into processes or horns. Markings cellular or punctate.
+Chromatophores, small plates of various forms.
+
+
+KEY TO THE SPECIES
+
+
+  Valves costate                                              biddulphiana
+
+  Valves not costate:
+
+    Markings cellular, angles elevated into horns             favus
+
+                       angles not elevated                    antediluviana
+
+    Markings punctate, angles with subconical processes and
+      long spines                                             granulata
+
+        spines short                                          rhombus
+
+        spines minute                                         smithii
+
+        processes truncate, valve elliptical                  turgida
+
+                            valve orbicular                   lævis
+
+        processes absent, valve divided by irregular lines    alternans
+
+        not so divided                                        reticulum
+
+
+BIDDULPHIA BIDDULPHIANA (SMITH)
+
+Frustule quadrangular with convex ends and rounded angles. Valve elliptical
+with undulated sides, divided by septa into three or more sections.
+Processes large, rounded, globular or subconical. Zone varying in width.
+Surface with rounded reticulations in longitudinal and transverse rows,
+except at the centre where they are concentric and smaller.
+
+_Conferva biddulphiana_ Smith (English Botany, 1807, Pl. 1762, upper
+figures).
+
+_Diatoma biddulphianum_ Ag.
+
+_Biddulphia pulchella_ Gray.
+
+Blue clay. Hoboken Tunnel. Along the coast.
+
+Pl. 7, Figs. 1, 2, 3, and 4.
+
+Quite variable in size and number of septate divisions. Fig. 3 is an
+unusual form with narrow zone, having but one row of large reticulations,
+evidently a young frustule.
+
+
+BIDDULPHIA FAVUS (EHR.) V. H.
+
+Frustule quadrangular, elevated at the angles into subconical processes
+oblique to the longitudinal axis. Valve triangular or quadrangular, plane,
+of two layers, the outer layer composed of large hexagonal cells in rows
+parallel to the sides, the inner of small puncta radiating from the centre.
+Zone punctate in quincunx, never found open.
+
+_Triceratium favus_ Ehr.
+
+Blue clay. Common along the coast.
+
+The quadrangular form occurs only southward.
+
+Pl. 6, Fig. 6. At "a" a cell showing the lower punctate layer. Pl. 40, Fig.
+16, a transverse section of a portion of the valve showing the cellular
+structure and the punctated lower stratum.
+
+
+{32}BIDDULPHIA ANTEDILUVIANA (EHR.) V. H.
+
+Frustules quadrangular, sometimes united in zig-zag chains. Valve
+quadrangular with more or less concave sides, sometimes cruciform. Surface
+with angular cells arranged in concentric and radiating lines increasing
+toward the circumference. At each angle is a large, rounded process, which,
+as well as the secondary layer, scarcely visible, is finely punctate.
+
+_Amphitetras antediluviana_ Ehr.
+
+_Amphitetras tessellata_ Shad.
+
+Blue clay. Rare.
+
+Pl. 6, Fig. 3.
+
+A cruciform variety occurs at Pensauken, N. J., artesian well (Coll. F. J.
+Keeley).
+
+
+BIDDULPHIA GRANULATA ROPER
+
+Valve elliptical-lanceolate, convex, with diagonal rows of puncta 12 in 10
+µ and sometimes with small scattered spurs. Processes inflated at the base,
+obtuse at the ends, which are curved outward toward alternate sides. Near
+each process and on opposite sides of the longitudinal axis is placed a
+stout spine bent or curved inward near the middle. Connective zone with
+diagonal rows of puncta smaller than those on the valve.
+
+Pavonia, N. J., artesian well. Fossil in the Pleistocene. Along the coast.
+Not common.
+
+Pl. 7, Fig. 6.
+
+
+BIDDULPHIA RHOMBUS (EHR.) WM. SM.
+
+Valve rhomboidal, sometimes triangular, with subconical processes. Surface
+convex with hexagonal reticulations, 7-9 in 10 µ, irregular at the centre
+and radiating to the circumference. Minute spurs are scattered over the
+surface, and on each side are usually two or three short spines.
+
+Common along the coast and fossil in the Miocene and later deposits.
+
+Pl. 7, Fig. 5 (somewhat inclined, as usually seen).
+
+
+BIDDULPHIA SMITHII (RALFS) V. H.
+
+Valve orbicular, convex, with reticulations 5 in 10 µ radiating from the
+centre and decreasing toward the margin and processes which are truncate. A
+short spine is found on each side half way between the processes. Zone
+narrow with fine puncta 12 in 10 µ in longitudinal rows.
+
+_Cerataulus smithii_ Ralfs.
+
+_Eupodiscus radiatus_ Wm. Sm.
+
+Blue clay. Along the coast southward.
+
+Pl. 7, Fig. 8.
+
+
+BIDDULPHIA TURGIDA (EHR.) WM. SM.
+
+Valve elliptical or orbicular, surface convex. Processes very large,
+cylindrical, placed obliquely and inclined by the torsion of the frustule.
+Between the processes are two stout spines, one on each side, frequently
+forked at the ends. Puncta fine, irregular at the centre and radiating
+toward the circumference.
+
+_Cerataulus turgidus_ Ehr.
+
+Blue clay. Along the coast. Quite variable in size.
+
+Pl. 7, Fig. 7.
+
+
+{33}BIDDULPHIA LÆVIS EHR.
+
+Valve suborbicular or triangular, with short, truncate processes. Surface
+with fine puncta about 13 in 10 µ radiating in straight or curved lines
+toward the circumference and with fine spurs at intervals. Nearer one
+process than the other, and about half way between centre and
+circumference, are two small spines, one on each side. Quite variable in
+size.
+
+Blue clay. Common along the coast.
+
+Pl. 7, Fig. 9.
+
+Fig. 10 (magnification about 260 diameters only) illustrates sporangial
+frustules discovered by Mr. T. Chalkley Palmer at Reedy Island, Delaware
+River. In frustules having a cylindrical form, the endochrome lines the
+cell-walls in the form of granules which become congregated toward the
+centre in the sporangia.
+
+
+BIDDULPHIA ALTERNANS (BAIL.) V. H.
+
+Valve triangular or, rarely, quadrangular, with sides straight or slightly
+concave, usually unequal. Angles obtuse, separated from the centre by
+costate lines. Surface with puncta of irregular shape, large at the centre,
+with smaller puncta interspersed. In many valves several lines appearing
+like costæ extend inward from the border in various directions. Angles with
+small puncta in transverse and longitudinal rows.
+
+_Triceratium alternans_ Bail.
+
+Blue clay. Along the coast.
+
+Pl. 6, Fig. 7 and probably Fig. 8.
+
+
+BIDDULPHIA RETICULUM (EHR.)
+
+Frustule quadrangular. Valve triangular with straight or concave sides and
+rounded angles. Surface convex at the centre and angles. Markings of
+unequal size, mostly larger at the centre, scattered; at the angles, small
+puncta in longitudinal rows.
+
+_Triceratium sculptum_ Shad.
+
+_Triceratium punctatum_ Br.
+
+_Triceratium obtusum_ Br.
+
+For explanation of the synonymy see "Biddulphoid Forms of N. A. Diat.,"
+Proc. Acad. Nat. Sci., 1900, p. 724.
+
+Blue clay. Along the coast.
+
+Pl. 6, Fig. 5.
+
+
+
+(_c_) ANAULEÆ
+
+EUNOTOGRAMMA WEISSE (1854)
+
+(eu, well, noton, a back, and gramma)
+
+Frustule quadrangular. Valve elliptical or lunate divided by septa which
+constrict the margin. Surface flat with punctate markings.
+
+
+EUNOTOGRAMMA LÆVE GRUN.
+
+Valve lunate with obtuse ends. Septa, from four to eleven or more. Surface
+with puncta in transverse and longitudinal rows, sometimes indistinct and
+scattered.
+
+Shark River. Rare. More common southward. Fossil at Buckshutem, N. J.
+
+Pl. 7, Fig. 11, and Pl. 10, Fig. 15.
+
+I am unable to distinguish between E. læve and E. debile, as intermediate
+forms occur.
+
+
+{34}TERPSINOË EHR.
+
+(terpsinoos, gladdening?)
+
+Frustules quadrangular, adnate in filaments, usually free. Valve elliptical
+or triangular, with undulating sides divided by septa into three or more
+sections.
+
+
+TERPSINOË AMERICANA (BAIL.) RALFS
+
+Valve lobed at each end or angle. Central space rounded, hyaline. Surface
+with fine puncta in radiating lines.
+
+Blue clay. Not common.
+
+Pl. 6, Fig. 10.
+
+
+TERPSINOË NOVÆ-CÆSAREÆ BOYER
+
+Valve triangular, with concave sides and broad angles equally three-lobed,
+separated from the central part by septa. Central space small or absent.
+Puncta delicate, radiating or scattered. L. of side 62 µ.
+
+Pleistocene clay at Buckshutem, N. J. Fossil at Wildwood, N. J.
+
+T. americana, forma trigona Pant.? (Le Diatomiste, Vol. 2, p. 207.)
+
+Pl. 6, Fig. 11.
+
+
+
+(_d_) EUODIEÆ
+
+EUODIA BAIL. (1860)
+
+(derivation uncertain; apparently from euodia, fragrant, probably a
+euphemism)
+
+Frustule in zone view cuneate. Valve semi-lunate, coscinodiscoid.
+
+
+EUODIA GIBBA BAIL.
+
+Valve with rounded markings, larger and scattered at the centre, radiating
+at the circumference and in indefinite straight rows at the semi-radius.
+
+Delaware Bay (Mann).
+
+Pl. 5, Fig. 1.
+
+I have not seen this in the Philadelphia material. The figure is drawn from
+a specimen from the Gulf Stream, S. Atlantic.
+
+
+
+{35}PENNATÆ
+
+Valve zygomorphous. Structure pinnate, not concentric. Valve divided either
+by a true raphe or cleft or by a linear space or line imitating a raphe.
+
+Divided into three Groups:
+
+1. _Fragilarioideæ._--Valves without a raphe; usually with a pseudoraphe or
+median line.
+
+2. _Naviculoideæ._--Either one or both valves with a true raphe.
+
+3. _Surirelloideæ._--Valves in which the raphe is concealed near the margin
+on one or both sides of each valve in a more or less elevated keel or wing.
+
+
+
+FRAGILARIOIDEÆ
+
+(_a_) _Tabellarieæ._--Valve symmetrical with respect to both the
+longitudinal and transverse axes; septate, not cuneate.
+
+(_b_) _Meridioneæ._--Valve symmetrical with respect to the longitudinal
+axis, asymmetrical to the transverse axis, cuneate, finely striated.
+
+(_c_) _Fragilarieæ._--Valve of varied shape, not cuneate; costate or with
+transverse rows of puncta.
+
+
+
+(_a_) TABELLARIEÆ
+
+Frustule in zone view rectangular, in valve view linear or
+linear-elliptical, sometimes constricted in the middle, symmetrical to both
+axes, not cuneate; with two or more septa or annuli.
+
+Chromatophores numerous, granular.
+
+_Rhabdonema._--Frustules with numerous septate partitions having one or
+several foramina. Transverse costæ or rows of coarse puncta.
+
+_Tabellaria._--Frustules with two to six nearly straight septa. Transverse
+striæ subtly punctate.
+
+_Grammatophora._--Frustules with two sinuate perforate curved septa.
+Transverse striæ subtly punctate.
+
+_Striatella._--Frustules with alternate partitions, septate or partly so.
+
+_Attheya._--Frustules not septate but with numerous annuli.
+
+
+RHABDONEMA KUETZ. (1844)
+
+(rhabdos, a rod, and nema, a thread)
+
+Frustules quadrangular, concatenate, composed of numerous septate
+partitions with transverse costæ or rows of puncta. Valves elliptical, with
+a pseudoraphe and transverse apparent costæ and punctate lines; the
+partitions with one or several foramina.
+
+Chromatophores in rosettes of various kinds (Karsten); usually parallel to
+the septa.
+
+
+RHABDONEMA ARCUATUM (LYNG.) KUETZ.
+
+Valve hyaline at the ends, with transverse rows of puncta producing the
+appearance of costæ between the rows; pseudoraphe distinct; foramen single.
+
+_Diatoma arcuatum_ Lyngbye.
+
+Common along the coast.
+
+Pl. 8, Figs. 1, 2, and 3; Pl. 40, Fig. 10.
+
+{36}According to T. H. Buffham (Jour. Quek. M. C., Series 2, Vol. 2, p.
+131), the frustules are of two kinds, those in which the length and breadth
+are the same and those which are much lengthened, with a wide hyaline
+girdle frequently in the middle. At the time of fructification the smaller
+frustules are attached to a larger one which produces a sporangium at the
+end of the girdle from which the other end of the frustule has disappeared,
+or, if the two halves of the frustule remain, two sporangia are formed.
+
+
+RHABDONEMA MINUTUM KUETZ.
+
+Frustules small; valve not smooth at the ends, elliptical or
+lanceolate-elliptical, with transverse rows of puncta; pseudoraphe
+distinct. Foramen single, alternating above and below in adjoining
+partitions.
+
+Common in the blue clay and along the coast.
+
+Pl. 8, Fig. 7 and Pl. 38, Fig. 11.
+
+
+RHABDONEMA ADRIATICUM KUETZ.
+
+Valve linear-lanceolate, with smooth angles; rows of puncta transverse, the
+intervals appearing as costæ, as in arcuatum. Foramina, three.
+
+Blue clay in the Pensauken and Pavonia deposits and along the coast.
+
+Pl. 8, Figs. 4, 5 and 6.
+
+
+TABELLARIA EHR. (1839)
+
+(tabella, a tablet)
+
+Frustules quadrangular, adnate in filaments, frequently found in zig-zag
+chains, united by a gelatinous isthmus, at length separating. Valve linear,
+inflated in the middle and at the ends; striæ transverse.
+
+Chromatophores numerous, small, along the zones.
+
+
+TABELLARIA FENESTRATA (LYNG.) KUETZ.
+
+Valve elongated; pseudoraphe narrow; transverse striæ faint. In the zone
+view a straight septum is shown at each end of a valve.
+
+Common, especially in the cedar swamps and ponds of the Pine Barren region,
+N. J.
+
+Pl. 8, Figs. 11 and 12.
+
+
+TABELLARIA FLOCCULOSA (ROTH) KUETZ.
+
+Valve linear, with median inflation larger than the terminal; pseudoraphe
+rather broad in the middle; transverse striæ subtly punctate. In zone view
+the frustules are quadrangular, or nearly so, with about six sometimes
+curved septa at one end alternating with those on the other end.
+
+_Conferva flocculosa_ Roth.
+
+Common especially in the Pine Barrens of New Jersey.
+
+Pl. 8, Figs. 8, 9 and 10.
+
+
+GRAMMATOPHORA EHR. (1840)
+
+(from gramma, a letter, and phoreo, I bear)
+
+Frustules quadrangular, adnate, in zig-zag, united by an isthmus, or,
+usually, found free; divided by two sinuate and perforate curved septa.
+Valve linear or oblong, sometimes with sinuate sides, and with a
+pseudoraphe and transverse punctate lines.
+
+Chromatophores granular.
+
+
+{37}GRAMMATOPHORA MARINA (LYNG.) KUETZ.
+
+Valve linear-elliptical, with smooth apices. Septum with a wide undulation
+near its origin, thence straight and incrassate at the end. Striæ in
+quincunx, 18-21 in 10 µ.
+
+_Diatoma marinum_ Lyngbye.
+
+Blue clay. Along the coast.
+
+Pl. 8, Figs. 17 and 18.
+
+
+GRAMMATOPHORA MARINA VAR. SUBTILISSIMA (BAIL.) V. H.
+
+Valve linear, slightly constricted near the smooth apices. Septum undulated
+near its origin and then straight, incrassate at the end. Puncta in
+quincunx very subtle, 34-36 in 10 µ.
+
+_Grammatophora subtilissima_ Bail.
+
+Grammatophora oceanica var. subtilissima (Bail.) V. H., according to De
+Toni. G. marina and G. oceanica are united by some authors; the latter has
+more subtle striæ.
+
+Along the coast.
+
+Pl. 8, Figs. 13 and 14.
+
+
+GRAMMATOPHORA SERPENTINA RALFS
+
+Valve linear-elliptical, long, measuring to 150 µ (De Toni); smooth at the
+apices. Septum with numerous undulations and hooked at the apex. Puncta in
+quincunx, 17 in 10 µ.
+
+Along the coast.
+
+Pl. 8, Fig. 21.
+
+
+GRAMMATOPHORA ANGULOSA VAR. HAMULIFERA (KUETZ.) GRUN.
+
+Frustule nearly quadrate; valve with rounded but not smooth apices. Septum
+bent into a sharp angle near its origin and ending in a broad hook. Puncta
+in transverse rows, 14 in 10 µ.
+
+Along the coast.
+
+Pl. 8, Figs. 15 and 16.
+
+
+GRAMMATOPHORA ISLANDICA EHR.
+
+Frustule oblong; valve elliptical-lanceolate. Septum robust with several
+undulations and hooked at the end. Pseudoraphe distinct; transverse rows of
+puncta, 10 in 10 µ.
+
+Reported by Kuetzing in the Atlantic Ocean and by Kain at Belmar, N. J. I
+have not found it on our coast and I believe, in some cases, it has been
+confused with _G. angulosa_ var. _hamulifera_. The figure is drawn from an
+Iceland form in H. L. Smith T. S., 186.
+
+Pl. 8, Figs. 19 and 20.
+
+
+STRIATELLA AG. (1832)
+
+(dim. of stria, referring to the lines on the frustule)
+
+Frustules tabulate, adnate in short, stipitate filaments, scarcely
+siliceous, divided into partitions, septate or partly so at alternate ends.
+
+
+{38}STRIATELLA UNIPUNCTATA (LYNG.) AG.
+
+Frustules with numerous bent septa extending the entire length. Valve
+lanceolate, somewhat unsymmetrical, subtly punctate, with pseudoraphe quite
+distinct.
+
+"The specific name is derived from the appearance of the endochrome which
+in the living specimen is invariably collected in a central mass with
+slender threads radiating in all directions toward the cell-wall" (Wm.
+Sm.). Pyrenoids cuneate, in the centre of the endochrome, numerous.
+
+Long Island Sound and along the coast.
+
+Pl. 8, Figs. 22 and 23.
+
+
+STRIATELLA INTERRUPTA (EHR.) HEIB.
+
+Frustules quadrangular, with robust alternate septa extending to the
+middle. Puncta in quincunx, 22 in 10 µ.
+
+_Tessella interrupta_ Ehr.
+
+Very rare along the coast.
+
+Pl. 8, Fig. 24. (From a form found at Stonington, Conn.)
+
+
+ATTHEYA WEST (1860)
+
+(named after Thomas Atthey)
+
+Frustules quadrangular, tabulate, with numerous annuli. Valve
+elliptical-lanceolate, with a pseudoraphe and a central punctum. Extending
+from each end is a strong spine half as long as the valve.
+
+
+ATTHEYA DECORA WEST
+
+The only species. Diagnosis of the genus. The valves are imperfectly
+siliceous, scarcely visible in balsam.
+
+Very local. Abundant at Shark River, N. J.
+
+Pl. 8, Fig. 25.
+
+
+
+(_b_) MERIDIONEÆ
+
+Valve symmetrical in zone and valve view along the sagittal line, but
+asymmetrical to the transverse axis, cuneate. In zone view sometimes with
+wedge-shaped septa. Valve finely striated, without central and usually
+without terminal nodules; a pseudoraphe present.
+
+_Licmophora._--Frustules cuneate in stipitate fan-shaped fascicles.
+
+_Meridion._--Frustules cuneate in spiral fascicles.
+
+
+LICMOPHORA AG. (1827)
+
+(licmos, a fan, and phoreo, I bear)
+
+Frustules wedge-shaped, joined together into fan-shaped, stipitate
+fascicles. Valve cuneate, rounded at both ends, septate. Chromatophores
+granular, round or oval in our species.
+
+
+{39}ANALYSIS OF SPECIES
+
+(In accordance, so far as it relates to our species, with the
+classification of C. Mereschkowsky, Diagnoses of New Licmophoræ, Nuova
+Notarisia, 1901.)
+
+
+  Placatæ--valve narrow, striæ very fine, septa superficial   flabellata
+
+  Dubiæ--valve bacilliform, septa shallow, frustule with
+    thick walls                                               ovulum
+
+  Paradoxæ--valve with lower end produced, striæ fine,        paradoxa
+    pseudoraphe distinct, septa deep                          gracilis
+                                                              tincta
+                                                              baileyi ?
+
+  Lyngbyeæ--valve narrow, attenuated at both ends, distinct,
+    septa deep                                                lyngbyei
+
+  Peristriatæ--valve broad, pseudoraphe wide, striæ robust    ehrenbergii
+
+
+LICMOPHORA FLABELLATA (CARM.) AG.
+
+Frustule elongate, narrow; valve narrow, lanceolate-cuneate, enlarged at
+the base; striæ very fine, 30 in 10 µ.
+
+_Echinella flabellata_ Carm.
+
+_Licmophora splendida_ Wm. Sm.
+
+Common along the coast.
+
+Pl. 9, Figs. 1 and 2.
+
+
+LICMOPHORA OVULUM MER.
+
+Valve ovate, attenuated to the rounded inferior apex; pseudoraphe
+indistinct, striæ fine, 24 in 10 µ. Zone view broad, cuneate, angles
+rounded, inferior apex broad; frustule robust, septa superficial, straight.
+(Mereschkowsky, in part.)
+
+Atlantic City. Common.
+
+Pl. 9, Figs. 8 and 9.
+
+
+LICMOPHORA PARADOXA (LYNG.) AG.
+
+Frustule broad, with rounded angles; septa curved; valve ovate, inferior
+apex produced. Pseudoraphe distinct; striæ varying from 25 below to 30
+above in 10 µ.
+
+_Echinella paradoxa_ Lyng.
+
+_Rhipidophora paradoxa_ Kuetz.
+
+Along the coast.
+
+Pl. 9, Figs. 6 and 7.
+
+
+LICMOPHORA GRACILIS (EHR.) GRUN.
+
+Frustule cuneate, narrow, with sinuate margin; valve clavate, linear at the
+base; striæ, 20 to 22 in 10 µ.
+
+New Rochelle. Along the coast.
+
+Pl. 9, Fig. 11.
+
+
+LICMOPHORA GRACILIS VAR. ELONGATA (KUETZ.) DE TONI
+
+As in the type, but more graceful and with deeper septa.
+
+_Rhipidophora elongata_ Kuetz.
+
+Along the coast. Not common.
+
+Pl. 9, Figs. 12 and 13.
+
+
+{40}LICMOPHORA TINCTA (AG.) GRUN.
+
+Frustules cuneate, narrow, usually found in twos. Valve clavate, hyaline,
+rather broad at the base; septa moderately deep; pseudoraphe indistinct;
+striæ, 27 at the base, 30 in the middle and 33 at the apex in 10 µ.
+
+_Gomphonema tinctum_ Ag.
+
+Along the coast. Abundant from about the middle of July to the middle of
+August.
+
+Pl. 9, Figs. 14 and 15.
+
+
+LICMOPHORA BAILEYI (EDW.) GRUN.
+
+Frustule broadly cuneate or with convex margins, rarely almost orbicular;
+valve spatulate or ovate with slender, produced base; septa very deep;
+pseudoraphe distinct; striæ 20 in 10 µ.
+
+_Podosphenia baileyi_ (Edw.) Lewis.
+
+Long Island Sound and upper coast of New Jersey.
+
+This form is placed in a doubtful position by Mereschkowsky. As it
+corresponds more closely to the Paradoxæ, it is placed here provisionally.
+The girdle face and apex of the valve are round, the pseudoraphe is
+distinct and the septa deep, but the stipe is short.
+
+Pl. 9, Fig. 10 and Pl. 38, Figs. 3 and 4.
+
+
+LICMOPHORA LYNGBYEI (KUETZ.) GRUN.
+
+Frustule cuneate, slightly rounded at the angles. Valve oblanceolate;
+pseudoraphe distinct; septa deep; striæ, 12 in 10 µ below, and 16 in 10 µ
+above.
+
+_Podosphenia lyngbyei_ Kuetz.
+
+Along the coast.
+
+Pl. 9, Figs. 3 and 4.
+
+
+LICMOPHORA EHRENBERGII (KUETZ.) GRUN.
+
+Frustule cuneate, broad. Valve obovate-lanceolate; pseudoraphe wide; striæ
+coarse, 8 in 10 µ, moniliform.
+
+_Podosphenia ehrenbergii_ Kuetz.
+
+Along the coast.
+
+Pl. 9, Fig. 5.
+
+
+MERIDION AG. (1824)
+
+(merizo, I divide)
+
+Frustules in zone view cuneate, adnate in circular or spiral fasciæ, at
+length becoming free. Valve symmetrical with respect to the longitudinal
+axis, more or less cuneate; costæ and striæ transverse.
+
+Chromatophores numerous, small, elongated, in irregular rows on the zone
+(Pfitzer).
+
+
+MERIDION CIRCULARE (GREV.) AG.
+
+Transverse costæ coarse, variable in number and distance apart, sometimes
+interrupted or indistinct; striæ interstitial, 16 in 10 µ.
+
+In springs and small streams of pure water.
+
+_Echinella circularis_ Grev.
+
+{41}Meridion constrictum Ralfs, sometimes given as a variety of M.
+circulare, differs only in the constriction below the apex. The two kinds
+of frustules are usually found growing together and as the variation is
+often extremely slight they are here included under the earlier name.
+
+Pl. 10, Figs. 1, 2 and 3.
+
+Fig. 1 represents the constricted form which is the more common. Fig. 3 is
+a sporangial form.
+
+The sporangial frustules vary in shape and size, some being long and
+slender, others clavate, but they are all more or less tumid in the middle,
+with costæ more indefinite than in perfect valves. All gradations occur,
+one end becoming shorter until the valve has the shape of the variety known
+as constrictum. It would seem, therefore, that the non-constricted form is
+a passage from the sporangial to the smaller or adult form, or is of no
+specific importance. All forms are found living together. The adult
+frustules are the smaller ones; it is from them that the sporangia are
+produced.
+
+Meridion intermedium H. L. Smith (Amer. Quart. Mic. Jour., Vol. 1, p. 12)
+is characterized by less evident costæ and is more delicate in general
+appearance. Some forms are capitate and others are not. Prof. Smith
+compares the M. intermedium with Peronia erinacea Bréb. and Arnott which he
+has named M. erinaceum, hitherto found only in Europe, and points out the
+relation of the two forms to Licmophora. An examination of the H. L. S.
+type slides of the two diatoms proves that Peronia has very delicate costæ
+and a distinct pseudoraphe not noticeable in Meridion. On the slide of
+Peronia are frustules exactly similar to certain of the sporangial
+variations of M. circulare.
+
+The fan-like arrangement of Licmophora, the marine form, and the circular
+chains of Meridion, the fresh-water genus, are similar. Both are stipitate
+at the beginning of their growth.
+
+
+
+(_c_) FRAGILARIEÆ
+
+Divided into three sections:
+
+_Diatominæ._--Valve circular, elliptical to linear, quadrate or cruciform,
+with transverse costæ; without raphe, a pseudoraphe sometimes wanting.
+
+_Fragilariinæ._--Valve elongate, with small central and terminal
+elevations, without costæ but with transverse punctate striæ; without
+genuine central nodule.
+
+_Eunotiinæ._--Valve lunate; a raphe sometimes partially formed with
+terminal nodules near the edges.
+
+
+
+DIATOMINÆ
+
+_Diatoma._--Frustules in filaments. Valve linear or elliptical, costate.
+
+_Plagiogramma._--Frustules in fasciæ or free. Valve costate.
+
+_Opephora._--Valve costate, with an inner punctate stratum.
+
+
+DIATOMA DE CANDOLLE (1805) em. HEIB. (1863)
+
+(diatemno, I cut in two)
+
+Frustules oblong or quadrate, adnate in filaments, attached by alternate
+angles and finally separating. Valve linear or elliptical, with transverse
+costæ and rows of puncta and a pseudoraphe.
+
+Chromatophores large granules without definite arrangement. (See Pl. 40,
+Fig. 11.)
+
+
+{42}DIATOMA VULGARE BORY.
+
+Valve elliptical-lanceolate, with apices sometimes rostrate or capitate;
+pseudoraphe narrow; costæ, 5 in 10 µ.
+
+Common everywhere in pure fresh water and extremely variable.
+
+Pl. 10, Figs. 9 and 10.
+
+Var. elongatum (Ag.) = var. ehrenbergii (Kuetz.)--elliptical-lanceolate,
+constricted near the apex.
+
+Var. grande (Wm. Sm.) Grun.--linear, elongated, constricted near the
+apices.
+
+Pl. 10, Fig. 4.
+
+Both of these varieties, with numerous intermediate forms, are abundant
+near Newtown Square. Varieties of Grunow, known as breve, ovate-lanceolate;
+productum, ovate-lanceolate with produced apices; capitulatum, lanceolate
+with capitate extremities, are mingled together in the same gathering.
+
+
+DIATOMA ANCEPS (EHR.) KIRCHN.
+
+Valve linear with rostrate apices; costæ robust; striæ delicate, 20 in 10
+µ. Zone view quadrangular.
+
+Common in fresh water.
+
+Pl. 10, Figs. 5 and 6. Fig. 11, Pl. 40, shows frustules containing the
+nuclei and chromatophores.
+
+
+DIATOMA HIEMALE (LYNG.) HEIB.
+
+Valve ovate-lanceolate to lanceolate; apices obtuse, not produced. Costæ
+not numerous, robust; striæ moniliform. Zone view quadrate, the costæ as
+septa deeply dividing the valve into convex elevations.
+
+Common in springs.
+
+Pl. 10, Figs. 7 and 8.
+
+In all species of Diatoma a punctum, or pore, is observed, usually at
+alternate ends of the two valves, by means of which a communication exists
+between adjoining frustules and causes them to adhere in zig-zag chains
+when partially separated.
+
+
+PLAGIOGRAMMA GREV. (1859)
+
+(plagios, on the side, and gramma, a letter)
+
+Frustules quadrangular, adnate in fasciæ, or free. Valve linear,
+elliptical, or elliptical-lanceolate, divided by two or more median and two
+terminal costæ or with a central and two terminal hyaline spaces.
+
+
+  Valve with two median and two terminal costæ:
+
+    Linear, pseudoraphe distinct                              pygmæum
+
+    Linear, with striæ at the ends                            wallichianum
+
+    Ovate-lanceolate                                          obesum
+
+  Valve without costæ but with central and terminal
+      nodules: pseudoraphe absent                             tessellatum
+
+
+{43}PLAGIOGRAMMA PYGMÆUM GREV.
+
+Valve linear-elliptical; pseudoraphe distinct; rows of granules transverse,
+usually six in each compartment, moniliform, three on each side.
+
+Blue clay. Not common.
+
+Pl. 10, Fig. 13.
+
+
+PLAGIOGRAMMA WALLICHIANUM GREV.
+
+Valve linear, rounded at the ends; pseudoraphe absent; transverse rows of
+granules, six or seven in each compartment, and two or three rows of
+smaller granules at each end.
+
+Blue clay. Not common.
+
+Pl. 10, Fig. 14.
+
+
+PLAGIOGRAMMA OBESUM GREV.
+
+Valve rhombic-lanceolate, the costæ scarcely visible; pseudoraphe rather
+wide; rows of granules, about seven in each compartment, slightly
+radiating.
+
+Blue clay. Not common.
+
+Pl. 10, Fig. 12.
+
+
+PLAGIOGRAMMA TESSELLATUM GREV.
+
+Valve elliptical-lanceolate; central space transversely elliptical to the
+major axis, half the diameter of the valve; terminal spaces more or less
+circular or ovate. Granular markings large, quadrangular, in transverse
+rows. Pseudoraphe not distinct. As the central space does not reach the
+margin, it is a question whether this form is a Plagiogramma or a new
+genus.
+
+Blue clay. Rare.
+
+Pl. 10, Fig. 11.
+
+
+OPEPHORA PETIT (1888)
+
+(ope, an opening, and phoreo)
+
+Frustule rectangular. Valve cuneiform, linear or elliptical-lanceolate,
+with broad, transverse striæ and a well-defined pseudoraphe or median area.
+
+The genus "portant des stries en forme de boutonnières," as Petit remarks,
+is quite near Fragilaria, under which the species here described were
+originally included. (See Schmidt's Atlas, Pl. 298, where numerous forms of
+F. pinnata are figured.)
+
+
+OPEPHORA SCHWARTZII (GRUN.) PETIT
+
+Valve obovate-lanceolate or nearly linear with rounded apices; striæ
+transverse, broad, 3 or 4 in 10 µ; median area lanceolate.
+
+An inner stratum, with puncta in transverse rows, is apparent.
+
+Blue clay. Not uncommon. Variable in size.
+
+Pl. 10, Figs. 16 and 19.
+
+
+OPEPHORA PACIFICA (GRUN.) PETIT
+
+Valve linear, oblong, with rounded apices. Median area linear, narrow;
+striæ punctate.
+
+Blue clay.
+
+Pl. 10, Fig. 18.
+
+Petit (Diat. Cap Horn) in his diagnosis states that the valves are
+cuneiform, but they are not always so.
+
+
+{44}OPEPHORA PINNATA VAR. LANCEOLATA N. VAR.
+
+Valve lanceolate; costæ slightly radiate, punctate; median area broad,
+lanceolate.
+
+Differs from O. pinnata in outline, radiation of the costæ and median area.
+
+Blue clay. Rare.
+
+Pl. 10, Fig. 17.
+
+
+
+FRAGILARIINÆ
+
+_Fragilaria._--Frustules in fasciæ. Valve with transverse striæ.
+Pseudoraphe indistinct.
+
+_Rhaphoneis._--Striæ radiate; pseudoraphe distinct.
+
+_Dimerogramma._--Pseudoraphe broad.
+
+_Trachysphenia._--Valve cuneiform.
+
+_Synedra._--Valve elongate.
+
+_Asterionella._--Frustules in star-shaped clusters.
+
+
+FRAGILARIA (LYNG.) RAB.
+
+(fragilis, because of the fasciæ easily breaking up)
+
+Frustules rectangular, adnate in fasciæ, soon breaking up. Valve
+lanceolate, oblong or elliptical in general outline, with convex or sinuate
+margins; without costæ; pseudoraphe narrow or indistinct; striæ transverse.
+Chromatophores vary according to species. In some they consist of four
+bands on the valves; in others they are granular (Mereschkowsky).
+
+Brun divides the genus into two sections, Fragilaria proper and Staurosira.
+The former, with an indistinct pseudoraphe, includes the species virescens,
+arctica, undata and linearis, while the latter, with distinct pseudoraphe,
+includes capucina, harrisonii, construens and parasitica.
+
+
+FRAGILARIA VIRESCENS RALFS
+
+Frustules in long fasciæ. Valve elliptical-lanceolate, obtuse at the
+apices; pseudoraphe indistinct; striæ, 17 in 10 µ, punctate.
+
+Very common in springs and pure streams. The fasciæ are often a foot or
+more in length.
+
+Pl. 10, Figs. 20 and 21.
+
+
+FRAGILARIA ARCTICA GRUN.
+
+Valve oblong or elliptical, 10 µ in length; striæ subtle, with coarse,
+short striæ at intervals on the margin and evident in zone view.
+
+Marine. Common at Cape May, N. J.
+
+Pl. 10, Figs. 22 and 23.
+
+
+FRAGILARIA UNDATA WM. SM.
+
+Valve in general outline linear-elliptical, with extremities produced;
+striæ subtle; pseudoraphe distinct.
+
+Fresh water.
+
+Pl. 10, Figs. 24, 25, 27, 28 and 29.
+
+
+{45}FRAGILARIA LINEARIS CSTR.
+
+Valve linear, with rounded apices; striæ subtle; pseudoraphe indistinct.
+
+Marine. Cape May.
+
+Pl. 10, Fig. 37. Fig. 36 is an indeterminate form occasionally found in the
+blue clay.
+
+
+FRAGILARIA CAPUCINA VAR. MESOLEPTA RAB.
+
+Valve linear, constricted at the hyaline middle; apices slightly produced;
+striæ, 17 in 10 µ. Quite variable in size.
+
+Schuylkill River. Morrisville (Keeley).
+
+Pl. 10, Fig. 34.
+
+
+FRAGILARIA HARRISONII (WM. SM.) GRUN.
+
+Frustules rectangular, solitary or in twos. Valve cruciform; pseudoraphe
+narrow, lanceolate; striæ robust, radiating in the middle, composed of
+confluent puncta, larger at the circumference.
+
+Blue clay.
+
+Pl. 10, Fig. 31.
+
+
+FRAGILARIA CONSTRUENS (EHR.) GRUN.
+
+Valve in general outline lanceolate, with produced apices; pseudoraphe
+lanceolate, distinct or broad; striæ subtle, 15 in 10 µ. L. of valve, 10-45
+µ.
+
+_Staurosira construens_ Ehr.
+
+_Odontidium tabellaria_ Wm. Sm.
+
+Blue clay.
+
+Pl. 10, Fig. 30.
+
+
+FRAGILARIA PARASITICA (WM. SM.)
+
+Frustules solitary or in twos. Valve lanceolate, sometimes constricted in
+the middle; pseudoraphe wide, lanceolate; striæ subtle. Parasitic on other
+diatoms.
+
+_Odontidium parasiticum_ Wm. Sm.
+
+Not common. Media (Palmer).
+
+In the constricted form it is known as F. construens var. binodis (Ehr.)
+Grun.
+
+Pl. 10, Fig. 35.
+
+An examination of the synonymy of the species of Fragilaria will convince
+the student of the difficulty of determining the correct name even in
+well-known forms. If all of the species of Fragilaria proper have granular
+chromatophores, and all of Staurosira are placcochromatic, a satisfactory
+division can be made, but so long as these facts are not known in all
+species, and as authors have repeatedly confused the two divisions, the
+nomenclature will be uncertain. F. harrisonii is probably in any case to be
+separated from the others. De Toni includes it under its original name of
+Odontidium, which genus he places near to Diatoma. The number of species in
+our locality is too limited to render further discussion of any value.
+
+
+{46}RHAPHONEIS EHR. (1844)
+
+(rhaphis, a needle)
+
+Frustule in zone view linear. Valve lanceolate or elliptical-lanceolate;
+pseudoraphe distinct; striæ radiating, moniliform.
+
+
+RHAPHONEIS AMPHICEROS EHR.
+
+Valve lanceolate, broad, with apices produced; striæ in curved lines,
+moniliform, the large granules in longitudinal lines.
+
+Blue clay.
+
+Pl. 10, Fig. 38.
+
+
+RHAPHONEIS AMPHICEROS VAR. RHOMBICA GRUN.
+
+Valve as in type form but shorter, with larger and more remote granules.
+
+Blue clay.
+
+Pl. 10, Figs. 39 and 40.
+
+
+RHAPHONEIS BELGICA VAR. INTERMEDIA GRUN.
+
+Valve lanceolate, rostrate; granules in longitudinal and nearly transverse,
+not radiating, lines.
+
+Absecon, N. J.
+
+Pl. 10, Fig. 41.
+
+
+DIMEROGRAMMA RALFS (1861)
+
+(dis, two, meros, a part, gramma, a letter)
+
+Frustules quadrangular, inflated at the angles, in fasciæ. Valve ovate or
+lanceolate; striæ moniliform, transverse or slightly radiate; median area
+or pseudoraphe broad, lanceolate.
+
+
+DIMEROGRAMMA MARINUM (GREG.) RALFS
+
+Valve lanceolate or linear and inflated in the middle; striæ moniliform,
+transverse or slightly radiate; median area linear or lanceolate, sometimes
+not reaching the smooth extremities; striæ, 8 in 10 µ.
+
+Pl. 12, Figs. 9 and 10.
+
+Fig. 9 differs in its lanceolate outline, in having four puncta on each
+side in a row, and in the striæ which are radiate.
+
+
+DIMEROGRAMMA SURIRELLA (EHR.) GRUN.
+
+Valve elliptical-lanceolate, with rounded apices; striæ moniliform,
+radiate; pseudoraphe narrow, lanceolate.
+
+Blue clay.
+
+Pl. 12, Fig. 11.
+
+
+{47}DIMEROGRAMMA MINUS (GREG.) RALFS
+
+Valve rhombic-lanceolate; striæ punctate, radiate; pseudoraphe lanceolate;
+apices smooth.
+
+Blue clay. Along the coast.
+
+Pl. 12, Figs. 12, 13, 14.
+
+
+TRACHYSPHENIA PETIT (1877)
+
+(trachys, rough, and sphen, a wedge)
+
+Frustules rectangular. Valve cuneiform with coarse puncta in transverse and
+longitudinal lines; pseudoraphe narrow, linear. One species only.
+
+
+TRACHYSPHENIA AUSTRALIS PETIT
+
+Characters of the genus. Valve small; puncta, 6 in 10 µ. Allied to
+Dimerogramma.
+
+Shark River, N. J. Rare.
+
+Pl. 12, Fig. 15.
+
+
+SYNEDRA EHR. (1830)
+
+(synedrion, a sitting together)
+
+Frustules adnate in small stipitate clusters or free. Valve elongate,
+linear or linear-lanceolate; pseudoraphe distinct; costæ absent.
+
+The genus Synedra has few distinctive characters. As Brun remarks (Diat.
+des Alpes et du Jura, p. 122), the dilatation of the extremities and the
+pseudo-nodule are of little value in classification, as the intermediate
+forms are so numerous. Fragilaria occurs in very long ribbons or fasciæ,
+Synedra in short fasciæ or radiating clusters. Fragilaria is seldom longer
+than three or four times the width, while Synedra is nearly always so. The
+former has fine, often subtle, markings and narrow pseudoraphe, while the
+latter has coarser punctate striæ and a more distinct pseudoraphe.
+
+Chromatophores usually consist of two bands, one on each of the valves.
+Karsten states that in the marine forms the chromatophores are oval or
+polygonal discs, each of which usually encloses a pyrenoid.
+
+
+SYNEDRA ULNA (NITZSCH) EHR.
+
+Frustules solitary or in twos. Valve 150-250 µ in length, linear or
+linear-lanceolate, with rostrate apices; striæ, 9 in 10 µ.
+
+Common in rivers and streams.
+
+Pl. 11, Figs. 4, 7 and 11 (?).
+
+Frequently interrupted in the middle. The distinction made by Wm. Smith as
+to the presence or absence of the central blank space is probably not
+necessary, as both forms are found which are otherwise identical.
+
+Fig. 5 represents the formation of a sporangial frustule which differs from
+the usual form in its inflated ends prolonged into rostrate apices. Figs. 1
+and 6 are sporangial frustules.
+
+
+{48}SYNEDRA BICEPS (KUETZ.) SCHMIDT
+
+Valve sublanceolate, inflated at the ends, apices rounded; central space
+not always distinct; pseudoraphe narrow; striæ radiate at the ends.
+
+This is not Kuetzing's species, if the descriptions and figures are
+accepted, nor is it H. L. Smith's Type No. 545, which is S. ulna var.
+danica, nor is it S. biceps Wm. Smith, but it is exactly Schmidt's form
+(Atlas, Pl. 303, Figs. 10-15).
+
+Schuylkill River.
+
+Pl. 11, Fig. 3.
+
+
+SYNEDRA DANICA KUETZ.
+
+Valve lanceolate, suddenly constricted at the rounded apices; central space
+frequently absent.
+
+Very common in streams.
+
+Pl. 11, Fig. 2.
+
+The figure represents an unusually large form. It differs from S. ulna only
+in its apices.
+
+
+SYNEDRA CAPITATA EHR.
+
+Valve long, linear, dilated into triangular acute apices; pseudoraphe
+distinct; striæ radiate at the ends.
+
+Blue clay.
+
+Pl. 11, Fig. 8.
+
+
+SYNEDRA ACUS KUETZ.
+
+Valve very narrow, lanceolate, acicular, with obtuse apices.
+
+Common in the Schuylkill River.
+
+Pl. 11, Figs. 9 and 18.
+
+
+SYNEDRA GOULARDI BRÉB.
+
+Valve constricted in the middle; apices sub-acute, sometimes slightly
+rostrate or capitate; central space evident.
+
+Neshaminy Creek (Palmer). Blue clay. Crum Creek.
+
+Pl. 11, Figs. 12 and 13.
+
+
+SYNEDRA PULCHELLA (RALFS) KUETZ.
+
+Valve lanceolate, tapering to the sub-acute, rostrate or slightly capitate
+apices; dilated at the central hyaline space; pseudoraphe distinct. Very
+variable in size.
+
+Crum Creek. Schuylkill River. Rather common.
+
+Pl. 11, Figs. 14, 15, 16.
+
+
+SYNEDRA PULCHELLA VAR. ABNORMIS MACCHIATI?
+
+Valve as in type form, except that one end is curved like a beak, as in S.
+hamata Wm. Sm., which it resembles.
+
+Not uncommon in the Schuylkill River.
+
+Pl. 11, Fig. 17.
+
+
+SYNEDRA OXYRHYNCHUS VAR. UNDULATA GRUN.
+
+Valve linear-lanceolate with produced rostrate apices, asymmetrical,
+sigmoid; pseudoraphe narrow; pseudo-nodule large.
+
+Common in fresh water.
+
+Pl. 12, Fig. 1.
+
+
+{49}SYNEDRA PULCHELLA VAR. FLEXELLA N. VAR.
+
+Frustule slightly attenuated at the ends, truncate, somewhat tumid in the
+middle and flexed. Valve lanceolate, with obtuse or subcapitate apices and
+with two almost imperceptible constrictions at the middle producing a tumid
+appearance; pseudoraphe distinct; pseudo-nodule absent. L. 56 µ; striæ,
+14-16 in 10 µ.
+
+Some valves are bent and incised on one side. The outline of the valve is
+that of pulchella.
+
+Common at Newtown Square.
+
+Pl. 12, Fig. 2.
+
+
+SYNEDRA RADIANS KUETZ.
+
+Frustules linear, in small fasciæ. Valve 34 µ in length, linear, with
+apices rostrate, obtuse, sometimes slightly capitate; pseudoraphe distinct;
+striæ about 20 in 10 µ.
+
+Fresh water.
+
+Pl. 10, Figs. 32 and 33.
+
+There is difficulty in recognizing S. radians K. as described and figured
+by different authors. On Plate 12, Fig. 8, I have drawn a specimen from H.
+L. Smith's Type Slide No. 574, labelled S. radians Kuetz., not Wm. Smith,
+which, however, corresponds closely to Smith's figure (Brit. Diat. 1, Pl.
+11, Fig. 89). De Toni gives S. radians Kuetz. as equivalent to S. tenera
+Wm. Sm. Van Heurck's figure of S. radians, and also the figure of ulna
+var., said to be synonymous with H. L. Smith's S. radians, which does not
+correspond to the specimens on Smith's slide in my possession, are
+confusing. In Van Heurck's Synopsis the striæ are said to be 16 or 17,
+while De Toni describes them as subtle and from 17 to 24 in 10 µ. The
+length is quite variable.
+
+Several species of Synedra resemble S. radians in the mode of growth, as
+they are adnate at first, in short bands, the frustules being sessile on
+other plants or objects, attached at the terminal nodules which, although
+scarcely visible in most forms, are probably present in all. The frustules
+are not closely connected at the free end, and soon become entirely
+detached.
+
+In Diatoma and Fragilaria, we find a punctum or pore at one end of a valve,
+but not in line with the pseudoraphe; in Synedra, a minute pore is usually
+found in the position of the terminal nodule and, in some species,
+indications of a central nodule are observed; the median line is wider but
+there is no raphe. In the fresh-water Synedræ, many of which are among the
+longest of diatoms, living in running streams, the terminal nodules are
+much more indistinct, while the marine forms have distinct terminal
+nodules, are not, as a rule, found in bands, and assume a more naviculoid
+outline.
+
+
+SYNEDRA VAUCHERIÆ VAR. PARVULA (KUETZ.) RAB.
+
+Valve lanceolate, with produced or rostrate apices; pseudo-nodule wide,
+excentric. L. 17 µ.
+
+Crum Creek.
+
+Pl. 12, Fig. 5.
+
+Fig. 6 represents a variety with coarser striæ from the Schuylkill River.
+Both are easily mistaken for Fragilaria intermedia.
+
+
+{50}SYNEDRA FULGENS (GREV.) WM. SM.
+
+Frustules geminate or flabellate on a stipe. Valve slightly inflated in the
+middle and at the apices; pseudoraphe narrow; striæ finely punctate,
+radiate at the ends.
+
+Marine. Atlantic City.
+
+Pl. 11, Fig. 10.
+
+
+SYNEDRA AFFINIS KUETZ.
+
+Valve lanceolate; striæ marginal, leaving a broad lanceolate pseudoraphe.
+
+Common along the coast.
+
+Pl. 12, Fig. 3.
+
+
+SYNEDRA AFFINIS VAR. PARVA (KUETZ.) V. H.
+
+Valve lanceolate, slender; striæ marginal, shorter than in the type.
+
+_Synedra gracilis_ Kuetz.
+
+Common along the coast.
+
+Pl. 12, Fig. 7.
+
+
+SYNEDRA AFFINIS VAR. TABULATA (AG.) V. H.
+
+Valve linear-lanceolate; striæ, 11 in 10 µ, very short.
+
+Not common. New Rochelle.
+
+Pl. 12, Fig. 4.
+
+
+ASTERIONELLA HASSALL (1855)
+
+(dim. of aster, a star)
+
+Frustules linear, slightly inflated at the ends, arranged in star-shaped
+clusters which soon break up. Valve linear, unequally inflated at the ends.
+
+
+ASTERIONELLA FORMOSA HASS.
+
+Valve clavate at the ends; striæ transverse, 17 in 10 µ, pseudoraphe very
+narrow or indistinct; an ovoid, hyaline area at each end.
+
+Newark, N. J. Broomall's Lake, Media (Palmer).
+
+Pl. 12, Figs. 19, 20, 21.
+
+
+ASTERIONELLA INFLATA HEIB.
+
+Valve linear, capitate at each end and tumid in the middle; striæ
+distinctly punctate; pseudoraphe indistinct, or not apparent. L. 30 µ.
+
+Fresh water. May's Landing, N. J.
+
+Pl. 12, Fig. 22.
+
+
+
+EUNOTIINÆ
+
+_Eunotia._--Frustules either free, in fasciæ or epiphytic. Valves arcuate.
+
+_Actinella._--Frustules, solitary or in small clusters, cuneate. Valve
+inflated at one end.
+
+
+{51}EUNOTIA EHR. (1837) em. GRUN. (1862)
+
+(eu, well, and noton, a back, referring to the strong, ridged dorsum)
+
+Frustules free, in fasciæ or epiphytic. Valve arcuate, without costæ,
+transversely striated; pseudoraphe absent; pseudo-nodules at each end.
+
+Chromatophores laminate along the concave zone and the valves.
+
+Very many species of Eunotia have been created to differentiate size and
+number of crenæ or undulations. An examination of certain fossil deposits
+of New England, as well as a gathering from the blue clay of Philadelphia,
+will show forms which vary infinitely. E. major and E. gracilis are
+scarcely distinguishable because of the intermediate variations. The striæ
+in all forms are punctate, but the puncta are frequently confluent.
+
+
+ANALYSIS OF SPECIES
+
+Eunotia is divided into two sections, Himantidium and Eunotia proper. In
+Himantidium, the frustules are in fasciæ, either short or long. Among those
+with short fasciæ are major, gracilis, and nymanniana; those with long
+fasciæ are pectinalis, solierolii and veneris. Eunotia proper includes
+frustules, free or epiphytic, in which the valves are not dentate on the
+dorsal margin, such as lunaris, hemicyclus, biceps and prærupta; and those
+in which the valves are dentate or crenate on the dorsum, such as monodon,
+triodon, diadema and others.
+
+The resemblance between Eunotia and Epithemia is noticeable. In both, the
+epiphytic character of the valve is seen in the shape of the frustule which
+is arched, and, in the free forms, is adherent at the ends only. In
+Epithemia, the median is more evident than the terminal nodules. In
+Eunotia, there is no median nodule, but the end nodules, in some species,
+are quite evident, and a tendency is shown to produce a very short raphe.
+The arrangement of puncta in valve view is similar in both genera.
+
+
+SECTION 1. HIMANTIDIUM
+
+EUNOTIA MAJOR (WM. SM.) RAB.
+
+Valve arcuate, linear, subcapitate, recurved. Striæ punctate, 12 in 10 µ L.
+90-190 µ.
+
+Common in fresh water.
+
+Pl. 13, Figs. 1 and 2.
+
+
+EUNOTIA GRACILIS (EHR.) RAB.
+
+Valve with sides parallel; apices slightly capitate and revolute; striæ, 10
+in 10 µ. The striæ on the connective membrane more delicate than in E.
+major. Intermediate forms occur.
+
+Common in fresh water.
+
+Pl. 13, Fig. 3. Fig. 4 is indeterminate.
+
+
+EUNOTIA NYMANNIANA GRUN.
+
+Valve small, curved, with parallel dorsal and ventral margins; apices
+truncate and recurved into dorsal elevations; striæ delicate.
+
+Blue clay. Not common.
+
+Pl. 13, Fig. 32.
+
+
+{52}EUNOTIA PECTINALIS (KUETZ.)
+
+Valve linear, arcuate, apices slightly rostrate; striæ distinctly punctate
+with puncta in longitudinal rows nearer together at the ends.
+
+_Himantidium pectinale_ Kuetz.
+
+Common in fresh water.
+
+Pl. 13, Figs. 6 and 7.
+
+The fasciæ are associated in large masses, sometimes an inch or more in
+diameter, and late in August are found a foot or more in length, of a
+beautiful chocolate color. Exceedingly abundant in the cedar-swamp streams
+of the Pine Barren regions of New Jersey. In winter, the dead frustules
+form a parchment-like coating upon the twigs, dead leaves, and other débris
+on the borders of streams.
+
+This species can scarcely be referred to Dillwyn's Conferva pectinalis, as,
+in his description, quoting Mueller, he says that "the filaments are of a
+dirty green color; seldom exceeding half an inch in length." Dillwyn's form
+is probably Fragilaria virescens, which equals Fragilaria pectinalis Ehr.,
+while Kuetzing's species is Fragilaria pectinalis Ralfs. It is not
+impossible to confuse Fragilaria virescens and Eunotia pectinalis when the
+zone only is seen under a low power and their mode of growth is similar.
+
+
+EUNOTIA PECTINALIS VAR. UNDULATA RALFS
+
+Valve as in type form, but with undulate margins.
+
+Common in the cedar swamps of New Jersey.
+
+Pl. 13, Figs. 8 and 10.
+
+
+EUNOTIA PECTINALIS VAR. SOLIEROLII (KUETZ.)
+
+Valve as in type, but with internal divisions as though in the process of
+reduplication.
+
+Not common. Moorestown, N. J. (Palmer).
+
+Pl. 13, Fig. 9.
+
+
+EUNOTIA PECTINALIS VAR. VENTRICOSA GRUN.
+
+As in type, but with the valves tumid in the middle.
+
+May's Landing, N. J.
+
+Pl. 13, Fig. 12.
+
+Fig. 11 is a form found in the blue clay. It differs in the coarser puncta
+from the var. ventricosa. In outline it resembles Eunotia arcus Wm. Sm.,
+which is Ceratoneis arcus (Ehr.) Kuetz., but the central nodule is not
+present as in the latter form, which connects Eunotia and Cymbella. It may
+be a form of E. luna Ehr. (A. S., Atlas, Pl. 286, Figs. 33 and 34.)
+
+
+EUNOTIA VENERIS KUETZ.
+
+Valve with convex dorsal and straight ventral margins, more or less
+constricted near the sub-acute apices. Striæ subtle, punctate.
+
+_Eunotia incisa_ Greg.
+
+May's Landing, N. J. Blue clay, Pavonia, N. J.
+
+Pl. 13, Figs. 30 and 31.
+
+
+{53}EUNOTIA (PROPER)
+
+EUNOTIA LUNARIS (EHR.) GRUN.
+
+Frustules sessile, solitary or in clusters. Valve arcuate, narrow,
+attenuated toward the apices, which are sometimes slightly rostrate or
+rostrate-capitate; transverse striæ, 14 in 10 µ, punctate.
+
+Very common in ditches, especially in the spring. Variable in length.
+
+Pl. 12, Figs. 24 and 25.
+
+
+EUNOTIA HEMICYCLUS (EHR.) RALFS
+
+Valve semicircular, with obtuse apices; striæ transverse, punctate;
+terminal nodules minute and indistinct.
+
+Hammonton Pond, N. J. Rare.
+
+Pl. 12, Fig. 23.
+
+The genus Pseudo-Eunotia was created by Grunow for forms like Eunotia, but
+without terminal nodules. As, however, in E. lunaris and E. hemicyclus
+nodules are evident, although not so large as in many species, I include
+these two forms as heretofore under Eunotia.
+
+
+EUNOTIA BICEPS EHR.
+
+Valve linear, slightly arcuate, narrow, with rounded apices somewhat
+revolute; striæ, 16 in 10 µ.
+
+May's Landing, N. J.
+
+Pl. 13, Fig. 27.
+
+
+EUNOTIA PRÆRUPTA EHR.
+
+Valve convex on dorsal side, apices dilated and truncate; striæ distant at
+centre.
+
+Common in the blue clay.
+
+Pl. 13, Fig. 5.
+
+
+EUNOTIA PRÆRUPTA VAR. BIDENS GRUN.
+
+Valve with two undulations; otherwise as in type.
+
+_Eunotia bigibba_ Greg.
+
+With the type.
+
+Pl. 13, Fig. 19.
+
+
+EUNOTIA ROBUSTA RALFS
+
+Valve arcuate, with several or numerous dorsal ridges or crenæ which
+decrease in relative size in proportion to their number. Striæ radiate,
+variable in distance apart, and in size of puncta.
+
+Ralfs included under this one name the following species named by
+Ehrenberg: E. diodon (2 crenæ); E. triodon (3); E. tetraodon (4); E.
+pentodon (5); E. diadema (6); E. heptodon (7); E. octodon (8); E. enneadon
+(9); E. decadon (10); E. hendecadon (11); E. duodecadon (12); E. serra
+(13); E. prioritis (14); all more than 20, E. polyodon. E. scalaris, with
+from 15 to 17 crenæ, and E. icosodon with 20, may be added.
+
+It is probable that all of these forms occur at May's Landing, N. J. The
+forms with more than eight crenæ are comparatively rare. In the blue clay
+those with from four to six are most common.
+
+Pl. 13, Figs. 13, 14, 15, 16, 17, 21, 24, 25.
+
+
+{54}EUNOTIA BACTRIANA EHR.
+
+Valve linear, apices revolute, acute, dentate on the dorsal margin, with
+one acute crena near each end.
+
+Tom's River, N. J. Rare.
+
+Pl. 13, Fig. 18.
+
+
+EUNOTIA BIDENTULA WM. SM.
+
+Valve with straight ventral margin, and with two undulations on the dorsum;
+apices large, rounded.
+
+May's Landing, N. J. Rare.
+
+Pl. 13, Fig. 20 (not Schumann's form, which has angular crenæ).
+
+
+EUNOTIA FORMICA EHR. VAR.?
+
+Valve turgid in the middle and at the apices which are unilaterally
+truncate.
+
+Pensauken, N. J. (artesian well).
+
+Pl. 13, Fig. 26 (not a typical form).
+
+The following are forms which appear to be indeterminate, or, in any case,
+are scarcely worthy of distinction by specific names, as might be said of
+others of the innumerable variations of this genus:
+
+Fig. 23, Pl. 13, probably a form of prærupta. Newtown Square.
+
+Fig. 28, Pl. 13, from the blue clay.
+
+Fig. 29, Pl. 13, an asymmetrical form, apparently abnormal, but not rare at
+May's Landing, N. J.
+
+Fig. 17, Pl. 38. Valve convex on the dorsal side, incised on the ventral;
+striæ about 15 in 10 µ, closer at the ends; L. 30 µ. Schuylkill River.
+
+Fig. 18, Pl. 38. Valve arcuate, asymmetrical, broader at one end; terminal
+nodules large; striæ, 10 in 10 µ; L. 47 µ. Gloucester, N. J., artesian
+well.
+
+Numerous variations of the above species are illustrated in Schmidt (Atlas,
+Pls. 285-291).
+
+
+ACTINELLA LEWIS (1865)
+
+(dim. of actin, a ray)
+
+Frustules solitary, or in small clusters, sub-cuneate or nearly linear.
+Valve arcuate, rounded at one end and suddenly widened at the other into a
+cup-shaped or lychnoid inflation.
+
+
+ACTINELLA PUNCTATA LEWIS
+
+Valve with fine, transverse striæ; on the margin, puncta at intervals;
+terminal nodules distinct.
+
+May's Landing, N. J.
+
+Pl. 12, Figs. 16, 17, 18.
+
+Fig. 17, from Tom's River, N. J., is an approach toward A. brasiliensis
+Grun.
+
+Fig. 18 represents the frustules geminate, a frequent occurrence.
+
+
+
+{55}NAVICULOIDEÆ
+
+In discussing the Naviculoid group, the general divisions of Cleve are here
+followed, and all diatoms having a true raphe are included. I have added
+the genus Epithemia and also Rhopalodia, partly because they contain a
+raphe of a certain kind and partly because they resemble the markings of
+certain of the genus Hantzschia in the following group, although in other
+respects there is probably no similarity.
+
+The difficulty of combining the numerous genera into groups which are
+naturally affiliated is avoided in the following arrangement based on
+superficial similarities, and is intended merely as an artificial key. To
+unite all forms having a raphe and which are symmetrical with valves
+similar and not sigmoid, under the one genus Navicula, as has been the
+custom previous to the publication of Cleve's monograph, would result in
+associating species differing in so many respects in relation to structure
+of the valve and cell contents that it seems advisable to retain the new
+genera, especially as the original genus is likely to be still further
+reduced when more is known of the structure and life history of the group.
+
+
+KEY TO THE GENERA
+
+
+  Valves dissimilar. Achnantheæ
+
+  symmetrical                                                 Cocconeis
+
+  asymmetrical
+
+    to the longitudinal axis                                  Anorthoneis
+
+    to the transverse axis                                    Rhoicosphenia
+
+    in zone view                                              Achnanthes
+
+  Valves similar and asymmetrical
+
+  asymmetrical to the longitudinal axis
+
+    valves parallel                                           Cymbella
+
+    valves not parallel                                       Amphora
+
+    valves keeled, twisted (sometimes symmetrical)            Amphiprora
+
+    valves keeled                                             Tropidoneis
+
+    valves reniform and keeled                                Auricula
+
+    median line sigmoid at the ends                           Scoliotropis
+
+  asymmetrical to the transverse axis
+
+    striæ punctate and costate                                Gomphoneis
+
+    striæ punctate                                            Gomphonema
+
+  Valves similar, symmetrical and sigmoid
+
+    striæ oblique                                             Pleurosigma
+
+    striæ at right angles                                     Gyrosigma
+
+  Valves similar, symmetrical, not sigmoid
+
+    striæ punctate, nodules elongated                         Frustulia
+
+    striæ subtly punctate, central nodule forked              Amphipleura
+
+    striæ punctate and reticulate, in two strata              Dictyoneis
+
+    striæ punctate and alveolate, in three strata             Trachyneis
+
+    striæ punctate, in two strata                             Brèbissonia
+
+    striæ interrupted by blank lines                          Anomoeoneis
+
+    striæ crossed by longitudinal lines                       Caloneis
+
+    striæ oblique, median fissures in opposite directions     Neidium
+
+    striæ punctate and costate, median line with horns        Diploneis
+
+    striæ punctate; valves separated by septate plates        Mastogloia
+
+    striæ punctate, central area dilated into a stauros       Stauroneis
+
+    striæ punctate, area without stauros or horns             Navicula
+
+    striæ costate, not punctate                               Pinnularia
+
+
+
+{56}ACHNANTHEÆ
+
+Frustules stipitate, free or parasitic. Valves cuneate, elliptical or
+suborbicular, dissimilar, bent along the transverse or the longitudinal
+axes, the lower valve with a true raphe and central and terminal nodules,
+the upper valve with a pseudoraphe or median line.
+
+_Rhoicosphenia._--Stipitate; valves with transverse puncta, bent along the
+transverse axis, cuneate, with diaphragms at the ends.
+
+_Anorthoneis._--Free; puncta radiate; valves bent slightly along the
+transverse axis, suborbicular.
+
+_Cocconeis._--Parasitic; valves elliptical, usually bent along the
+longitudinal axis; striæ punctate, transverse and longitudinal.
+
+_Achnanthes._--Stipitate; valves lanceolate or elliptical, bent along the
+transverse axis; striæ transverse, punctate; costæ sometimes present.
+
+
+RHOICOSPHENIA GRUN. (1860)
+
+(rhoicos, curved, and sphen, a wedge)
+
+Frustule in zone view curved; valves cuneate, dissimilar, the upper with a
+pseudoraphe, the lower with a raphe.
+
+Chromatophore a single plate along both valves, and one of the inner walls
+of the zone. Conjugation as in Gomphonema, with which it is generally
+associated in classification.
+
+
+RHOICOSPHENIA CURVATA (KUETZ.) GRUN.
+
+Valve clavate, with rounded apex and base; lower valve with raphe, a narrow
+axial area and slightly radiate, punctate striæ; the upper valve with a
+narrow pseudoraphe and parallel striæ; a short diaphragm at the ends of
+each valve. Length usually from 15 to 25 µ, but frequently of twice the
+size.
+
+Common in Crum Creek.
+
+Pl. 19, Figs. 25, 26, 27.
+
+
+ANORTHONEIS GRUN. (1868)
+
+(anorthos, not straight)
+
+Valves dissimilar, the upper valve with an excentric axial area, the lower
+with an excentric raphe.
+
+
+ANORTHONEIS EXCENTRICA (DONK.) GRUN.
+
+Valves orbicular, with radiating, punctate striæ, closer at the
+circumference, producing the appearance of a border. Axial area not
+reaching the ends. Frustules occur free on the sands of the sea-shore. L.
+25 to 50 µ.
+
+Belmar, N. J.
+
+Pl. 16, Figs. 30 and 31.
+
+
+{57}COCCONEIS EHR. (1835) em. GRUN. (1868)
+
+(coccos, a berry)
+
+Valves elliptical, dissimilar, the upper valve with a pseudoraphe and the
+lower with a genuine raphe and nodules, usually with a rim or annulus.
+Frustules epiphytic.
+
+Cocconeis is generally considered as a degenerated form of Mastogloia, as
+indicated by the "obsoletely loculiferous rim." The frustules are usually
+bent along the longitudinal axis, probably because of the attachment to the
+curved stems of water-plants.
+
+The cell contents of only a few species are known. In C. pediculus, a
+single chromatophore occurs on the inside of the upper valve. In
+conjugation, two cells open and secrete a gelatinous mass from which an
+auxospore is formed.
+
+Cleve separates the forms having a loculiferous rim (Cocconeis) from those
+without a rim (Eucocconeis). As the rim is easily detachable, the
+distinction is often made with difficulty.
+
+
+COCCONEIS SCUTELLUM EHR.
+
+Valves elliptical, the upper with a linear or lanceolate pseudoraphe and
+coarse puncta in transverse and radiating lines; the lower valve with much
+finer puncta in radiating lines, a lanceolate axial area and, sometimes, a
+loculiferous rim.
+
+Along the coast. Common, but extremely variable.
+
+Pl. 16, Fig. 21 (upper valve). Fig. 18, var. ?
+
+
+COCCONEIS SCUTELLUM VAR. ORNATA GRUN.
+
+Upper valve with linear axial area, and transverse and radiating punctate
+lines which end at the border in a double row of finer puncta; lower valve
+with much finer puncta, a lanceolate axial area and a loculiferous rim.
+
+Atlantic City. Common.
+
+Pl. 16, Figs. 27 and 28.
+
+The forms along the coast vary infinitely both in size and appearance. The
+var. ornata is very abundant along the entire coast. In any gathering,
+valves are found with or without the rim which is frequently seen detached.
+The upper valve is sometimes without the double row of puncta. Fig. 21
+represents an upper valve more coarsely punctate than usually occurs. Very
+many intermediate forms might be noticed.
+
+
+COCCONEIS PEDICULUS EHR.
+
+Valves rhombic-elliptical, very convex, somewhat asymmetrical; the upper
+valve with a linear pseudoraphe, sometimes widened near the ends, and
+slightly radiating, finely punctate striæ; lower valve with narrow, axial
+area and finely punctate, radiating striæ.
+
+Not uncommon in fresh water. Abundant in a ditch at Paoli, Pa.
+
+Pl. 16, Figs. 23 and 24.
+
+
+COCCONEIS PLACENTULA EHR.
+
+Valve elliptical; upper valve with a linear or lanceolate axial area, and
+punctate striæ in transverse and radiating rows, the puncta at equal
+distances; the lower valve with a lanceolate axial area, radiating rows of
+puncta, and a wide border of finely punctate, radiating striæ, separated
+from the central part of the valve by a narrow hyaline zone.
+
+Common in salt, brackish and fresh water.
+
+Pl. 16, Figs. 19 and 20.
+
+
+{58}COCCONEIS PLACENTULA VAR. LINEATA (EHR.) V. H.
+
+As in the type, except that the upper valve has the puncta arranged in
+zig-zag, giving the appearance of sinuous, longitudinal lines.
+
+Common along the coast.
+
+Pl. 16, Fig. 29.
+
+C. pediculus and C. placentula are the only species I have found in fresh
+water. Cleve states that the former occurs also in brackish water.
+
+The following are among the species placed by Cleve in a new genus,
+Eucocconeis, distinguished by the absence of a loculiferous rim.
+
+
+COCCONEIS DIRUPTA GREG.
+
+Valves elliptical, the lower with fine puncta in slightly radiating lines,
+a narrow axial area and a central area dilated into a lanceolate,
+stauriform space; the terminal fissures turned in opposite directions; the
+upper valve similar to the lower valve except in the absence of raphe and
+nodules.
+
+Along the coast. New Rochelle.
+
+Pl. 16, Fig. 22 (lower valve).
+
+
+COCCONEIS PELLUCIDA GRUN.
+
+Valves elliptical, the upper with broad axial area on each side of which
+are fine, longitudinal rows of short striæ; the lower valve with more
+numerous longitudinal rows, a marginal line and indistinct raphe; the
+terminal fissures small and turned in opposite directions.
+
+New Rochelle.
+
+Pl. 16, Figs. 25 and 26.
+
+In the var. minor Grun. the median line of the lower valve is sometimes
+slightly sigmoid.
+
+
+ACHNANTHES BORY (1822)
+
+(achne, froth or down, and anthos, a flower)
+
+Frustules stipitate, solitary or in short fasciæ, flexed. Valves elliptical
+or lanceolate, naviculoid, dissimilar, the lower with a raphe and median
+and terminal nodules, and the upper with a pseudoraphe or median space.
+
+The genus has no apparent affinity with any other.
+
+
+ACHNANTHES LONGIPES AG.
+
+Valves linear-elliptical, obtuse at the apex, sometimes slightly
+constricted in the middle. Connective zone with transverse, subtly punctate
+striæ, interrupted by longitudinal lines. Central nodule of lower valve
+dilated into a stauros reaching the margin. Valves costate, the costæ
+alternating with double rows of fine puncta.
+
+Along the coast, in estuaries.
+
+Pl. 16, Figs. 1 and 2.
+
+A. longipes is the only species in our locality considered by Cleve as
+belonging to the genus; the other forms, distinguished by the absence of
+costæ, are included in the genus Achnanthidium of Kuetzing.
+
+In A. longipes, the chromatophores consist of scattered, rounded granules,
+while in Achnanthidium the chromatophore is a single plate along the upper
+valve, or a double one {59}along the connective zone. It is necessary,
+therefore, to distinguish between A. longipes and the following group, but,
+because of the long continued union of all of the stipitate forms having
+the general appearance of a true Achnanthes, I shall continue to describe
+the local species under the generally accepted name.
+
+
+ACHNANTHES BREVIPES AG.
+
+Valves without costæ; striæ moniliform; upper valve with excentric
+pseudoraphe or median line; otherwise as in A. longipes.
+
+Along the coast, in estuaries.
+
+Pl. 16, Fig. 3.
+
+
+ACHNANTHES SUBSESSILIS KUETZ.
+
+Valves linear-elliptical, rounded at the ends; upper valve with excentric
+pseudoraphe; striæ moniliform, puncta smaller than in A. brevipes.
+
+Along the coast, in estuaries.
+
+Pl. 16, Figs. 4, 5, 6.
+
+The three species described above are named from the length of the stipe,
+but this varies considerably and is not of special significance.
+
+
+ACHNANTHES INFLATA (KUETZ.) GRUN.
+
+Valves more or less inflated in the middle, usually with the stauros of the
+lower valve asymmetrical and wider than in A. subsessilis, with which it
+agrees in size and markings.
+
+Gloucester, N. J. (artesian well).
+
+Pl. 16, Figs. 7 and 8.
+
+
+ACHNANTHES COARCTATA (BRÉB.) GRUN.
+
+Valves lanceolate, oblong, broad at the ends and constricted in the middle.
+Stauros wide; pseudoraphe of the upper valve excentric; striæ slightly
+radiate on the lower valve; puncta small.
+
+Blue clay.
+
+Pl. 16, Fig. 9.
+
+
+ACHNANTHES LANCEOLATA (BRÉB.) GRUN.
+
+Valves more or less elliptical; striæ radiating, 12 in 10 µ, punctate; on
+the lower valve a horse-shoe shaped hyaline space on one side of the
+centre; on the upper valve an irregular stauros, not reaching the margin.
+L. 8-20 µ.
+
+In springs. Abundant at Newtown Square.
+
+Pl. 16, Figs. 10, 11, 12.
+
+
+ACHNANTHES EXIGUA GRUN.
+
+Valves oblong-lanceolate, with rostrate ends, sometimes slightly
+constricted in the middle. Stauros rather wide; striæ punctate, radiating,
+22 in 10 µ. L. 10-12 µ.
+
+_Stauroneis exilis_ Kuetz. (not Achnanthes exilis Kuetz.)
+
+Frequently found in aquaria where I have kept it growing continuously for
+years.
+
+Pl. 16, Figs. 14 and 15.
+
+
+ACHNANTHES LINEARIS FORMA CURTA H. L. SMITH
+
+Frustules solitary or geminate. Valves linear-elliptical, or
+elliptical-lanceolate. Lower valve without distinct axial area; upper valve
+with axial area widened in the middle; striæ slightly radiate (?). L. 7 µ.
+One of the smallest of diatoms.
+
+{60}This form I found in a pure gathering covering the sides of a
+greenhouse tank at Elm, N. J. It was sent to Prof. H. L. Smith, who
+determined it as forma curta of A. linearis.
+
+Pl. 16, Figs. 16 and 17.
+
+
+ACHNANTHES DANICA (FLOEGEL) GRUN.
+
+Valves rhombic-lanceolate, with subacute ends. Striæ, 25 in 10 µ, radiate.
+Lower valve with stauros widened toward the margin, and cleft into three
+divisions.
+
+Pavonia, N. J. (artesian well).
+
+Pl. 16, Fig. 13.
+
+I have seen the lower valve only. Cleve states that the upper valve is
+costate with "alternating fine lineolæ twice as close as the costæ."
+
+
+CYMBELLA AG.  (1830)
+
+(cymbe, a boat)
+
+Frustules free, stipitate or enclosed in tubes. Valve boat-shaped; median
+line asymmetrical, straight or curved.
+
+Chromatophore single, covering the entire interior of the frustule, except
+the ventral part of the zone and the median lines. Its longitudinal axis is
+on the dorsal part of the zone. A pyrenoid lies in a fold of the
+chromatophore on the dorsal part.
+
+The genus includes the former genera of Cocconema, characterized by
+stipitate forms, and Encyonema in which the frustules are frequently
+enclosed in gelatinous tubes.
+
+
+SECTION 1.--CYMBELLA PROPER. FRUSTULES FREE OR SOMETIMES STIPITATE
+
+CYMBELLA HETEROPLEURA (EHR.) KUETZ.
+
+Valve nearly symmetrical, lanceolate, with rostrate, produced apices;
+median line nearly straight; axial area linear, widened in the middle;
+striæ radiate, punctate.
+
+Blue clay.
+
+Pl. 18, Fig. 10.
+
+
+CYMBELLA CUSPIDATA KUETZ.
+
+Valve broad, elliptical, with rostrate, somewhat acute, apices and nearly
+straight, ventral margin; median line straight, axial area linear, widened
+in the middle; striæ radiate, punctate.
+
+Blue clay.
+
+Pl. 18, Fig. 17.
+
+
+CYMBELLA NAVICULIFORMIS AUERSWALD
+
+Valve linear-elliptical, with abruptly produced apices; ventral margin
+straight; median line almost straight; axial area narrow, central area
+large, rounded; striæ distant in the middle, closer at the ends.
+
+Fresh water.
+
+Pl. 18, Fig. 6.
+
+
+CYMBELLA EHRENBERGII KUETZ.
+
+Valve lanceolate, with ventral margin nearly straight and apices
+sub-rostrate; median line straight, excentric; axial area narrow; central
+area widened in the middle; striæ coarsely punctate.
+
+Fresh water.
+
+Pl. 18, Fig. 9.
+
+
+{61}CYMBELLA AFFINIS KUETZ.
+
+Valve about three times as long as broad, strongly convex on the dorsal
+side and straight on the ventral; apices sub-rostrate; striæ punctate;
+axial area narrow, not widened in the middle; median line curved; a small
+or indistinct punctum on the ventral side of the median line (not shown in
+the figure).
+
+Common in ponds. Abundant in East Park Reservoir.
+
+Pl. 18, Fig. 18.
+
+
+CYMBELLA EXCISA (KUETZ.) DE TONI
+
+Valve as in affinis, but with tumid and excised ventral margin; a punctum
+is found on the ventral side (not shown in the figure).
+
+According to Cleve this is a variety of C. affinis.
+
+Common in ponds.
+
+Pl. 18, Figs. 15, 19?
+
+
+CYMBELLA PARVA (WM. SM.) CL.
+
+Valve semi-lanceolate, with produced apices; ventral margin slightly tumid;
+axial area narrow; striæ coarsely but obscurely punctate.
+
+C. affinis and C. parva are quite variable, the latter differing by its
+lanceolate form and the absence of a punctum, which, however, is sometimes
+difficult to recognize. In a gathering of C. parva, it is quite possible to
+find numerous abnormal forms which appear to be sporangial, so that
+specific distinctions are difficult if based on occasional specimens.
+
+Common in ponds.
+
+Pl. 38, Fig. 14.
+
+
+CYMBELLA AMPHICEPHALA NÆGELI
+
+Valve unequally elliptical, with broad, rostrate apices; axial area narrow;
+median line straight; central area small, rounded; striæ, 12 in 10 µ on the
+dorsal, closer on the ventral, side and at the ends.
+
+Kirkwood Pond, N. J.
+
+Pl. 18, Fig. 16.
+
+
+CYMBELLA SINUATA GREG.
+
+Valve linear-elliptical, gibbous on the ventral side; axial area
+indistinct; central area widened on the ventral side nearly to the margin.
+
+Crum Creek.
+
+Pl. 18, Fig. 13.
+
+
+SECTION 2.--COCCONEMA. FRUSTULES STIPITATE
+
+CYMBELLA ASPERA (EHR.) CL.
+
+Valve large, cymbiform, arcuate on the dorsal, slightly gibbous on the
+ventral side; axial area linear, broad, slightly widened in the middle; no
+row of puncta on the ventral side. The puncta form curved longitudinal
+lines and the innermost row on the ventral side appears sometimes distant
+from the others, but not as in C. cistula.
+
+_Cocconema asperum_ Ehr.
+
+_Cymbella gastroides_ Kuetz.
+
+{62}Not Cymbella gastroides H. L. Smith, Type No. 118, which is C. mexicana
+A. S., having a punctum in the middle of the central nodule; in outline it
+is like C. gastroides var. minor Kuetz.
+
+Blue clay.
+
+Pl. 18, Fig. 1 (an unusual form, but it resembles Grunow's. (Diat. Franz
+Jos. Land, Pl. 1, Fig. 7.)
+
+
+CYMBELLA CYMBIFORMIS (KUETZ.) BRÉB.
+
+Valve cymbiform, slightly gibbous on the ventral margin; apices broad,
+somewhat truncate; a punctum occurs on the ventral side of the median line;
+striæ, 8 in 10 µ, closely punctate.
+
+Kirkwood Pond, N. J.
+
+Pl. 18, Fig. 2.
+
+
+CYMBELLA CISTULA (HEMPR.) KIRCHN.
+
+Valve cymbiform, with gibbous ventral margin and truncate apices; a
+distinct row of several puncta occurs below the median line in typical
+forms.
+
+Blue clay.
+
+Pl. 18, Fig. 3.
+
+
+CYMBELLA LANCEOLATA (EHR.) KIRCHN.
+
+Valve cymbiform, with gibbous ventral margin; apices truncate; axial area
+very narrow, scarcely widened in the middle; striæ with fine close puncta.
+
+Kirkwood Pond, N. J.
+
+Pl. 18, Fig. 4.
+
+
+CYMBELLA MEXICANA (EHR.) A. S.
+
+Valve broad, with gibbous ventral margin and sub-rostrate, truncate apices;
+median line with reflexed terminal fissures; striæ with coarse puncta; a
+large punctum occurs in the centre of the central area.
+
+Blue clay.
+
+Pl. 18, Fig. 5.
+
+
+CYMBELLA TUMIDA (BRÉB.) V. H.
+
+Valve cymbiform, with gibbous ventral margin and abruptly rostrate ends;
+median line arcuate; axial area narrow; central area large, orbicular;
+below the central nodule is a punctum; striæ punctate.
+
+Crum Creek.
+
+Pl. 18, Fig. 7.
+
+
+SECTION 3.--ENCYONEMA. FRUSTULES IN TUBES
+
+CYMBELLA VENTRICOSA KUETZ.
+
+Valve lunate, with straight or slightly gibbous ventral margin; axial area
+indistinct; median line straight or nearly so; striæ punctate.
+
+Very common, but extremely variable. The ventral margin is sometimes
+straight and sometimes quite gibbous.
+
+Pl. 18, Figs. 14, 22; Pl. 38, Fig. 16; Pl. 40, Fig. 8.
+
+{63}C. ventricosa is considered by some authors to be equivalent to C.
+affinis var. semicircularis Lagerst., Encyonema prostratum (Berk.) Ralfs,
+E. cæspitosum Kuetz. and E. auerswaldii Rab. H. L. Smith's Type Slide of C.
+ventricosa Ag. is said to equal C. affinis Kuetz., but the specimens appear
+to me to be equivalent to C. ventricosa Kuetz. Cleve unites many forms,
+including E. cæspitosum, under C. ventricosa.
+
+
+CYMBELLA PROSTRATA (BERK.) CL.
+
+Valve semi-elliptical, obtuse at the apices, which are sometimes prolonged
+and turned downwards; median line straight, terminal nodules distant from
+the ends; axial area narrow, central area rounded; striæ in radiating,
+slightly curved lines, indistinctly punctate.
+
+Common in fresh water; occasional in brackish.
+
+Pl. 18, Fig. 21 (represents a frequent variation).
+
+
+CYMBELLA PHILADELPHICA N. SP.
+
+Valve semi-elliptical-lanceolate, with rounded apices; ventral margin
+strongly gibbous; terminal nodules distant from the ends; axial area broad,
+central area widened on the dorsal side; striæ radiate, not curved nor of
+unequal length, indistinctly punctate, 10 in 10 µ on the dorsal, 8 in 10 µ
+on the ventral side. L. 86 µ.
+
+This form approaches Encyonema prostratum (Berk.) Ralfs, Schmidt's Atlas,
+Pl. 71, Fig. 7, but differs in the striæ and the axial and central areas.
+
+Blue clay of Philadelphia. Rare.
+
+Pl. 18, Fig. 8.
+
+
+CYMBELLA TRIANGULUM (EHR.) CL.
+
+Valve semi-elliptical, with acute ends; median line straight; ventral side
+half the width of the dorsal, with straight, slightly convex or concave
+margin; striæ radiate, coarsely punctate.
+
+_Gloeonema triangulum_ Ehr.
+
+Baker's Run, Willistown, Pa.
+
+Pl. 18, Fig. 24.
+
+
+CYMBELLA TURGIDA (GREG.) CL.
+
+Valve semi-elliptical, with acute ends; ventral margin gibbous; ventral
+side half the width of the dorsal; median line straight; terminal fissures
+turned downwards; axial area broad; striæ radiate, coarsely punctate.
+
+Baker's Run, Willistown, Pa.
+
+Pl. 18, Fig. 23.
+
+
+CYMBELLA TURGIDA (GREG.) CL. VAR. ?
+
+Valve lunate, with gibbous ventral margin; median line straight; terminal
+fissures turned downwards near the ends; axial area lanceolate, striæ
+radiate on the dorsal side, 8 in 10 µ, punctate, 9 on the ventral side,
+closer at the ends where they are convergent. L. 65 µ. Not a typical form.
+
+Willistown, Pa.
+
+Pl. 18, Fig. 12.
+
+
+CYMBELLA RHOMBOIDEA N. SP.
+
+Valve rhomboidal, with acute ends; dorsal part one and a half times the
+width of the ventral; median line nearly straight, with terminal fissures
+turned downwards near the ends; axial area broad, not widened in the
+middle, except slightly on the ventral side; striæ {64}radiate, distant in
+the middle of the dorsal side where they are 7 in 10 µ, coarsely punctate,
+the puncta in longitudinal lines, 9 in 10 µ on the ventral side, closer at
+the ends. L. 69 µ.
+
+Baker's Run, Willistown, Pa.
+
+Pl. 18, Fig. 11.
+
+
+CYMBELLA GRACILIS (RAB.) CL.
+
+Valve semi-lanceolate, with acute ends; median line nearly straight, with
+terminal fissures turned downwards, distant from the ends; axial area
+linear; ventral margin straight or slightly gibbous in the middle.
+
+Hammonton Pond, N. J.
+
+Pl. 18, Fig. 20.
+
+
+CYMBELLA LACUSTRIS (AG.) CL.
+
+Valve elliptical-lanceolate, with obtuse ends, nearly symmetrical; median
+line straight, terminal fissures distant from the ends; striæ radiate in
+the middle, convergent at the ends, coarsely lineate.
+
+Belmar, N. J.
+
+Pl. 18, Fig. 25.
+
+
+AMPHORA EHR. (1840)
+
+(amphora, a jar)
+
+Valves asymmetrical along the longitudinal axis, as in Cymbella, but with
+the plane passing through the dorsal and ventral sides of one valve at an
+angle with that of the other. As Cleve states, Cymbella and Amphora are
+forms of Navicula "with both valves similar and asymmetrical along the
+longitudinal axis," and the difference between Cymbella and Amphora is in
+the "degree of asymmetry." If, following H. L. Smith's diagrams (Lens, Vol.
+2, 1873, p. 66), we assume that the usual form of the valve in Navicula is
+elliptical or lanceolate, and the zone view is rectangular, we have in
+Cymbella an arcuate median line and a more or less reniform valve, while
+the zone view remains rectangular with the valves parallel. Now, if the
+valves are asymmetrical along the longitudinal axis, and one side of one
+valve is separated from the corresponding side of the opposite valve by a
+wider connective zone than is the case on the other side, the transverse
+section of the frustule will appear cuneate, as in Amphora, and the
+connective zone will be wider on one side than the other. When, therefore,
+we examine an entire frustule as it is usually seen, we shall find the two
+raphes of the valves in focus at the same time on the ventral side, and, by
+changing the focus, the convex sides of the same valves are seen, the
+dorsal view with, usually, a wider connective zone. As an illustration,
+compare Figs. 5 and 6, on Plate 15, Fig. 6 being the ventral, and Fig. 5
+the dorsal view.
+
+As Amphoræ are epiphytic or parasitic, they are considered, as Cleve
+remarks, like Achnanthes and Cocconeis, as "degenerated forms."
+
+Chromatophores usually single, lying on the ventral connective zone.
+Mereschkowsky describes nine forms.
+
+Cleve divides the genus into a number of groups as follows:
+
+_Amphora proper._--Connective zone not complex; valves with longitudinal
+lines on the dorsal side; coarsely punctate or costate.
+
+_Diplamphora._--Zone complex; otherwise as in Amphora.
+
+_Halamphora._--Longitudinal lines absent; frustule elongate, with
+protracted ends.
+
+{65}_Oxyamphora._--Zone complex; longitudinal lines absent; frustule
+elliptical; valve lunate, with or without a central stauros; striæ
+punctate.
+
+_Amblyamphora._--Zone complex; frustule rectangular; valve lunate; striæ
+punctate; axial and central areas indistinct.
+
+_Psammamphora._--Zone not complex; frustule rectangular; central nodule
+frequently dilated to a stauros; no axial or central area.
+
+_Cymbamphora._--Valve semi-lanceolate; median line straight, approximate to
+the ventral margin.
+
+
+AMPHORA
+
+AMPHORA ROBUSTA GREG.
+
+Frustule elliptical, truncate; valve lunate, with straight ventral margin;
+median line biarcuate; ventral side with coarse, radiate striæ, 6 in 10 µ,
+on both sides of the median line.
+
+Along the coast.
+
+Pl. 15, Fig. 1.
+
+
+AMPHORA PROTEUS GREG.
+
+Frustule elliptical, truncate; valve lunate, with straight ventral margin;
+median line biarcuate; no central area. Striæ on the dorsal side not
+interrupted, 9 in 10 µ. Ventral side striate toward the ends.
+
+Differs from A. robusta chiefly in size and coarseness of puncta. Extremely
+variable in size.
+
+Common along the coast.
+
+Pl. 15, Figs. 5, 6, and 19.
+
+
+AMPHORA OVALIS (BRÉB.) KUETZ.
+
+Frustule elliptical, truncate; valve lunate; median line biarcuate; striæ
+on dorsal side 10-16 in 10 µ.
+
+_Var. libyca (Ehr.) Cl._--Central area distinct on the dorsal side.
+
+_Var. pediculus (Kuetz.) Cl._--Central area and nodule quite distinct.
+Striæ finer than in var. libyca.
+
+Common in ponds. Quite variable.
+
+Pl. 15, Fig. 7.
+
+
+AMPHORA GIGANTEA VAR. FUSCA A. S.
+
+Frustule elliptical; valve lunate, with straight ventral margin. Axial area
+absent on the dorsal side; dorsal striæ, 10 in 10 µ, punctate. Ventral part
+hyaline except at the ends, which are obliquely striated, with short,
+punctate lines. L. 70-120 µ.
+
+Absecon, N. J.
+
+Pl. 38, Fig. 1.
+
+
+DIPLAMPHORA
+
+AMPHORA CRASSA GREG.
+
+Valve linear-elliptical, with obtuse, incurved ends. Median line biarcuate.
+Axial and central areas indistinct on the dorsal side; striæ coarsely
+punctate, interrupted by a longitudinal line on the dorsal side.
+
+Along the coast.
+
+Pl. 15, Fig. 3.
+
+
+{66}AMPHORA AREOLATA GRUN.
+
+Valve with straight ventral margin; median line straight, approximate to
+the ventral margin; axial area indistinct; several longitudinal lines
+crossed by apparent costæ which alternate with rows of fine puncta.
+
+Blue clay. Rare.
+
+Pl. 15, Fig. 11.
+
+
+HALAMPHORA
+
+AMPHORA COFFÆIFORMIS (AG.) KUETZ.
+
+Frustule lanceolate, truncate; zone with numerous divisions. Valve arcuate
+on the dorsal and nearly straight on the ventral side; ends protracted or
+slightly capitate.
+
+_A. aponina_ Kuetz.
+
+_A. salina_ Wm. Sm.
+
+Along the coast.
+
+Pl. 15, Figs. 8 and 18.
+
+
+OXYAMPHORA
+
+AMPHORA LINEOLATA EHR.
+
+Frustule membranaceous, elliptical, truncate, with broad ends. Zone with
+numerous divisions. Dorsal part striated transversely; ventral side with
+longitudinal lines.
+
+_A. plicata_ Greg.
+
+_A. hyalina_ H. L. Smith, Type No. 64.
+
+Along the coast.
+
+Pl. 15, Figs. 9 and 10.
+
+
+AMPHORA OSTREARIA BRÉB.
+
+Frustule oblong, with rounded angles. Zone with five or more divisions
+transversely striated. Central area narrow, biarcuate; central nodule
+dilated to a stauros. Valve narrow, with arcuate dorsal and straight
+ventral margin, acute at the ends. Striæ transverse, finely punctate.
+
+_A. vitræa_ Cl.; _A. porcellus_ Kitton; _A. quadrata_ Bréb.; _A. elegans_
+Greg. Appearance varies according to the position of the valve.
+
+Along the coast.
+
+Pl. 15, Figs. 12 and 21.
+
+
+AMPHORA LÆVIS GREG.
+
+Frustule oblong, hyaline and membranaceous. Valve linear or slightly
+arcuate, with ventral margin tumid in the middle; ends obtuse; central
+nodule dilated to a stauros; median line very narrow, biarcuate, coinciding
+with the dorsal margin at the ends; striæ transverse, punctate.
+
+Blue clay.
+
+Pl. 15, Fig. 13.
+
+
+AMPHORA ACUTA GREG.
+
+Valve lunate, with acute ends; ventral margin straight; ventral side very
+narrow. Central nodule dilated to a stauros; striæ transverse, punctate.
+
+Along the coast.
+
+Pl. 15, Fig. 20.
+
+
+{67}AMBLYAMPHORA
+
+AMPHORA OBTUSA GREG.
+
+Frustule rectangular. Valve linear, obliquely rounded at the ends, with
+arcuate dorsal, and straight ventral, margin; median line biarcuate; striæ,
+18-20 in 10 µ.
+
+Along the coast. Common.
+
+Pl. 15, Fig. 4.
+
+
+PSAMMAMPHORA
+
+AMPHORA ARENARIA DONK.
+
+Frustule hyaline, rectangular, slightly tumid in the middle, with rounded
+angles. Valve linear with broad ventral side and straight or sinuate
+ventral margin. Striæ, 24-27 in 10 µ (Cleve).
+
+Common along the coast.
+
+Pl. 15, Fig. 17.
+
+The distinction between A. obtusa and A. arenaria is not always evident if
+the valves alone are seen. The former has a complex zone, the latter a
+simple zone, and the valve has finer striæ. Cleve's descriptions and
+references in regard to these two forms do not agree with the descriptions
+and figures of H. L. Smith, or with the figures of Schmidt. The valves of
+most Amphoræ are capable of assuming various outlines according to their
+position.
+
+
+AMPHORA OCELLATA VAR. CINGULATA CLEVE
+
+Frustule rectangular. Valve linear, with dorsal margin arcuate and the
+ventral margin straight. Central nodule with a stauros on the dorsal side.
+
+Squan River, N. J.
+
+Pl. 15, Figs. 14 and 15.
+
+
+CYMBAMPHORA
+
+AMPHORA ANGUSTA VAR. EULENSTEINII GRUN.
+
+Valve lanceolate, acute at the ends. Median line straight, approximate to
+the margin. Axial area widened on the dorsal side, indistinct on the
+ventral; striæ punctate.
+
+_A. eulensteinii_ A. S.
+
+Common along the coast.
+
+Pl. 15, Fig. 16.
+
+On Pl. 40, Figs. 21, 22, and 23, I have attempted, imitating H. L. Smith's
+figures (Lens, l.c.), to illustrate the difference in the transverse
+sections of Navicula, Cymbella and Amphora.
+
+Fig. 21 represents the transverse section of a convex Navicula, in which
+the valves ecg and fdh are parallel, and the median nodules c and d are
+central.
+
+Fig. 22 is a transverse section of Cymbella in which the valves are nearly
+parallel and the median nodules are excentric. The girdles on one side, ea
+and af, are narrower than gb and bh on the other side.
+
+Fig. 23 is a transverse section of an Amphora in which the valves appear in
+zone view with the median nodules of both valves on the same side. The
+girdles on the ventral side, ea and af, are narrower than gb and bh on the
+dorsal side. The girdles on the dorsal side are seldom as broad as gb and
+bh, the valve extending over a great part of the dorsal side to g' and h'.
+
+
+{68}AMPHIPRORA EHR. (1843)
+
+(amphi, on both ends, and prora, a prow)
+
+Frustule twisted in the longitudinal axis, constricted in the middle; zone
+complex, with numerous divisions crossed by fine striæ. Valve lanceolate,
+acute. The raphe confined within a sigmoid keel or extension of the valve;
+the central and terminal nodules indistinct. Striæ transverse, punctate,
+with coarser striæ at the junction of the keel and lower part of the valve.
+
+Chromatophores single, with indented border except in A. pulchra, in which
+there are two chromatophores with entire borders.
+
+
+AMPHIPRORA ALATA KUETZ.
+
+Frustule with a row of puncta at the junction line. Valve linear, acute at
+the ends. Median line sigmoid. Striæ lineate on the lower part of the
+valve, punctate on the keel.
+
+Along the coast. Not common.
+
+Pl. 14, Fig. 3.
+
+
+AMPHIPRORA PULCHRA BAIL.
+
+Frustule with sigmoid connective zone. Valve very convex, with sinuate keel
+and junction lines evident. In zone view and in valve view, one half of the
+frustule, owing to the elevation of the keel, is wider than the other half.
+Striæ punctate, coarser on the keel.
+
+Not uncommon along the coast.
+
+Pl. 14, Figs. 1 and 2.
+
+
+AMPHIPRORA CONSPICUA GREV.
+
+Valve linear or elliptical, with acute ends. Median line sigmoid, but the
+junction lines not evident. Striæ lineate, with coarser lines near the
+middle.
+
+Not common. Port Penn, Delaware River.
+
+Pl. 14, Fig. 4.
+
+
+AMPHIPRORA ORNATA BAIL.
+
+Frustule membranaceous, constricted in the middle, with well-marked folds
+extending from the junction line in both directions. Valve lanceolate,
+constricted in the middle and with protracted ends. Keel undulate on the
+edge.
+
+A beautiful, transparent and delicate form, the only fresh-water species in
+our locality.
+
+Delaware Water Gap, Pa.
+
+Pl. 14, Figs. 6 and 7.
+
+
+AMPHIPRORA PALUDOSA WM. SM.
+
+Frustule membranaceous, constricted, with truncate ends. Valve linear, with
+acute ends. Striæ scarcely visible.
+
+Cape May (Cleve).
+
+Pl. 14, Fig. 5.
+
+
+TROPIDONEIS CLEVE (1891)
+
+(tropis, a keel)
+
+Frustule oblong, constricted in the middle; keel not sigmoid. Axial area
+not evident. Striæ very fine, punctate, in longitudinal lines.
+
+
+{69}TROPIDONEIS LEPIDOPTERA (GREG.) CLEVE
+
+Valve with straight, median excentric line. Keel unilateral, projecting
+above the median line in zone view; central area small. Transverse striæ
+finely punctate. As usually seen, the valve is inclined. According to
+Karsten there are two chromatophores on the connective zone, each divided
+into four parts, each of which contains a large oval pyrenoid.
+
+_Amphiprora lepidoptera_ Greg.
+
+Along the coast.
+
+Pl. 14, Figs. 8 and 9.
+
+
+AURICULA CASTRACANE (1873)
+
+(auricula, the ear, the shape of the valve)
+
+Frustule globose. Valve reniform or cymbiform, elevated into a keel which
+is not sigmoid. Median line biarcuate. Differs from Amphiprora in not
+having a sigmoid keel.
+
+
+AURICULA MUCRONATA (H. L. SMITH) PERAGALLO
+
+In zone view, the median line deeply bisects the longitudinal axis, ending
+in a mucronate central nodule. Connective zone complex. Valve very complex,
+with ventral margin nearly straight and raphe excentric. Central nodule
+near the margin, terminal nodules small. Striæ, 35-40 in 10 µ (Cleve).
+Chromatophore single, on the ventral part.
+
+_Amphora mucronata_ H. L. Smith.
+
+_Amphora (?) insecta_ Grun.
+
+_Auricula insecta_ (Grun.) Cleve.
+
+"A rare and very curious pelagic species" (Peragallo, Diat. Villefranche).
+
+Prof. H. L. Smith included this form in his first century of "Species
+Typicæ Diatomacearum," which was issued prior to 1876, the date of
+publication, in Schmidt's Atlas, of Amphora insecta Grun.
+
+Atlantic City, N. J. Rare.
+
+Pl. 15, Fig. 2.
+
+
+SCOLIOTROPIS CLEVE (1894)
+
+(scolios, twisted, and tropis, a keel)
+
+Frustule linear, oblong. Median line sigmoid near the ends. Valve with
+transverse costæ alternating with two intermediate rows of puncta in
+oblique lines.
+
+
+SCOLIOTROPIS LATESTRIATA VAR. AMPHORA CLEVE
+
+Valve asymmetrical, with the median line curved. Frustule sub-acute at the
+ends. Median lines not on the same side of each valve of the frustule.
+
+Abundant at Cape May, N. J. Not common elsewhere.
+
+Pl. 14, Figs. 10 and 11.
+
+
+GOMPHONEIS CLEVE (1894)
+
+(gomphos, a peg, and neis (naus))
+
+Valve elongated, asymmetrical to the transverse axis; axial area narrow;
+central area rounded, stigmatic; striæ radiating, costæ alternating with
+double rows of fine puncta. An indistinct, longitudinal line near the
+border.
+
+Chromatophores and conjugation have not been determined.
+
+
+{70}GOMPHONEIS HERCULANEUM (EHR.) CL.
+
+Valve clavate, with rounded apex; costæ, 13 in 10 µ, alternating with
+double rows of fine puncta, 22 in 10 µ, in oblique rows; axial area narrow,
+central area rounded, with one stigma.
+
+_Gomphonema capitatum_ Ehr var. _herculaneum_ Ehr., H. L. S., Type Slide
+No. 177.
+
+Common in the blue clay.
+
+Pl. 19, Fig. 2.
+
+Pl. 38, Fig. 15, zone view of young frustule.
+
+
+GOMPHONEIS MAMILLA (EHR.) CL.
+
+Valve lanceolate, with rounded apex and base; striæ costate, 10 in 10 µ,
+alternating with double rows of fine puncta; axial area linear, sometimes
+oblique, central area small, with one or more stigmas.
+
+Blue clay. Rare.
+
+Pl. 19, Fig. 1.
+
+In one frustule I noticed one valve with one stigma and the other with four
+stigmas.
+
+The difference between G. mamilla and G. elegans is not very great. In the
+latter the central area is larger and the longitudinal lines not so near to
+the margin. The stigmas form a circlet. There appears to be a coincidence
+in the relation of Gomphoneis to Gomphonema, and that of the true
+Achnanthes to the group described by Cleve under Achnanthidium. In
+Gomphoneis and Achnanthes the striation is both costate and punctate while
+in Gomphonema and Achnanthidium the striation is punctate only.
+
+
+GOMPHONEMA AG. (1824)
+
+(gomphos, a peg, and nema, a filament)
+
+Valve elongated, asymmetrical with respect to the transverse axis; striæ
+transverse, usually radiate, punctate.
+
+Chromatophore band single, the middle lying on one zone.
+
+In conjugation, according to Thwaites and Pfitzer, from two mother cells,
+which do not form a positive union, two auxospores are developed parallel
+to the original frustules. In Plate 19, Fig. 19, I have drawn a
+representation of the auxospore formation as I have frequently observed it
+in a gathering sent me by Mr. T. C. Palmer, containing G. angustatum, a
+common species in this locality. The sagittal plane of the valve of the
+auxospore is at right angles to the plane of the valve of the mother cell.
+Two valves of one of the mother cells are seen separated, one on each side
+of the auxospore which is nearly twice the length of the original
+frustules. The two valves of the other mother cell are not shown as they
+are not usually found closely united. In the figure one valve alone of the
+auxospore is seen, the opposite valve not being in focus. The valves of the
+auxospore are usually more or less arcuate, as in Cymbella, to which the
+genus is closely allied.
+
+Grunow divides Gomphonema into two groups, Asymmetricæ and Symmetricæ,
+according to the presence or absence of stigmas. Cleve suggests Stigmaticæ
+and Astigmaticæ as more suitable in order to agree with the Cymbellæ. The
+Stigmaticæ are found chiefly in fresh water, sometimes in brackish. All of
+the marine forms belong to the Astigmaticæ, which, however, include some
+common fresh-water forms. Many species of Gomphonema are stipitate, some
+occur in gelatinous masses, and others are free.
+
+
+{71}GOMPHONEMA MONTANUM SCHUM.
+
+Valve slightly biconstricted, with obtuse apex and basis, somewhat cuneate;
+axial area linear, widened in the middle unilaterally; stigma, one; striæ
+about 11 in 10 µ, more distant in the middle, punctate.
+
+_Gomphonema subclavatum_ var. _montana_ (Schum.) Cl.
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 19, Fig. 3.
+
+
+GOMPHONEMA GEMINATUM LYNG.
+
+Valve biconstricted, with large, rounded, sub-truncate apex and broad,
+sub-truncate basis; striæ, 9 in 10 µ, radiate in the middle, alternately
+longer and shorter, transverse at the basis and near the apex where they
+again radiate, coarsely punctate, puncta, 12 in 10 µ. Axial area linear;
+central area rounded, with several large stigmas in a longitudinal row;
+terminal fissures hook-shaped.
+
+Blue clay.
+
+Pl. 19, Fig. 4.
+
+
+GOMPHONEMA LANCEOLATUM VAR. INSIGNIS (GREG.) CL.
+
+Valve lanceolate; axial area narrow; central area unilateral with one
+stigma; striæ with coarse and distant puncta.
+
+Common and variable.
+
+_Gomphonema insigne_ Greg.
+
+Pl. 19, Figs. 6 and 12.
+
+Fig. 12 shows a unilateral central area. Fig. 6 is more clavate in outline
+with small central area. In both forms the coarse puncta are in distinct
+longitudinal lines in the middle.
+
+
+GOMPHONEMA ACUMINATUM VAR. TURRIS (EHR.) CL.?
+
+Valve clavate, with cuneate, acute apex; axial area distinct; central area
+unilateral with one stigma.
+
+Blue clay.
+
+Pl. 19, Fig. 11.
+
+
+GOMPHONEMA ACUMINATUM VAR. TURRIS (EHR.) CL.
+
+Valve clavate, with cuneate apiculate apex and narrow basis; axial area
+narrow, with a unilateral central space; stigma opposite the short striæ;
+striæ more radiate in the upper part, distant in the middle.
+
+Smith's Island, Delaware River.
+
+Pl. 19, Fig. 5.
+
+
+GOMPHONEMA ACUMINATUM VAR. CORONATA (EHR.) CL.
+
+Valve twice constricted, with broad, cuneate apex; striæ radiate in the
+middle, convergent near the apex and radiate at the apex. Variable in size
+and outline.
+
+Blue clay. Fresh water. Common.
+
+Pl. 19, Fig. 7.
+
+
+GOMPHONEMA ACUMINATUM VAR. TRIGONOCEPHALA (EHR.) CL.
+
+Valve broad, with cuneate apex; axial area narrow; central area unilateral
+with one stigma.
+
+Pavonia, N. J., artesian well.
+
+Pl. 19, Fig. 20.
+
+
+{72}GOMPHONEMA CONSTRICTUM EHR.
+
+Valve clavate, constricted beneath the abruptly rounded apex, gibbous in
+the middle, striæ alternately longer and shorter; axial area narrow,
+central area unilateral, with one stigma.
+
+Common in fresh water.
+
+Pl. 19, Fig. 8.
+
+
+GOMPHONEMA SPHÆROPHORUM EHR.
+
+Valve clavate, with capitate or rostrate-capitate apex and narrow basis;
+axial area very narrow; central area small, unilateral, with one stigma.
+
+Common in fresh water.
+
+Pl. 19, Figs. 9 and 10. Fig. 10 appears to be a transitional form having a
+more distinct axial area and rostrate apex.
+
+
+GOMPHONEMA AUGUR EHR.
+
+Valve broadly clavate, truncate and apiculate at the apex; basis sub-acute;
+axial area distinct; central area small, unilateral with one stigma; striæ
+with distant puncta.
+
+Blue clay. Willistown, Pa.
+
+Pl. 19, Fig. 21.
+
+
+GOMPHONEMA INTRICATUM KUETZ.
+
+Valve narrow, lanceolate, slightly gibbous in the middle; axial area
+distinct; central area transverse with one stigma; striæ parallel. Quite
+variable.
+
+Common in fresh water.
+
+Pl. 19, Fig. 14.
+
+
+GOMPHONEMA ANGUSTATUM KUETZ.
+
+Valve lanceolate, with sub-rostrate apex and basis; axial area indistinct;
+central area unilateral, with one small stigma; striæ slightly radiate,
+indistinctly punctate.
+
+Very common in fresh water.
+
+Pl. 19, Figs. 18 and 19.
+
+Fig. 19, as stated above, represents the formation of an auxospore.
+
+
+GOMPHONEMA ÆQUALE GREG.
+
+Valve linear-lanceolate, nearly symmetrical, with capitate apex and basis;
+axial area narrow; central area unilateral, with one stigma; striæ radiate
+in the middle, slightly convergent at the ends.
+
+_Gomphonema intricatum var. æquale_ (Greg.) Cl.
+
+Blue clay. Not common.
+
+Pl. 19, Fig. 15.
+
+
+GOMPHONEMA SARCOPHAGUS GREG.
+
+Valve linear, irregular in outline, with rounded apex and basis; axial area
+distinct; central area small, unilateral, with one stigma; striæ irregular
+with coarse, distinct puncta.
+
+Occasional in fresh water.
+
+Pl. 19, Fig. 16.
+
+
+GOMPHONEMA CAPITATUM EHR.
+
+Valve clavate, broad at the sub-truncate apex and slightly constricted, or
+with parallel margins; axial area linear, central area stellate, with one
+stigma; striæ in the middle alternately longer and shorter.
+
+Blue clay.
+
+Pl. 19, Fig. 22.
+
+
+{73}GOMPHONEMA PARVULUM VAR. MICROPUS (KUETZ.) CL.
+
+Valve clavate, with rounded apex and basis; axial area indistinct; central
+area unilateral, with a small stigma; striæ distant in the middle.
+
+Common.
+
+Pl. 19, Fig. 17.
+
+
+GOMPHONEMA VENTRICOSUM GREG.
+
+Valve clavate, with broad apex and produced, rounded basis; axial area
+narrow, widened in the middle; stigma one; striæ distant in the middle,
+finely punctate.
+
+Blue clay.
+
+Pl. 19, Fig. 13.
+
+
+GOMPHONEMA OLIVACEUM LYNG.
+
+Valve clavate, with broad apex and narrow basis; axial area very narrow;
+central area irregular, without stigma; striæ radiate, finely punctate.
+
+Very common.
+
+Pl. 19, Fig. 23.
+
+
+GOMPHONEMA BRASILIENSE VAR. DEMERARÆ GRUN.?
+
+Valve lanceolate, with sub-cuneate apex and narrowed basis; axial area
+lanceolate, broad; no stigma; median fissures remote; striæ parallel, 12 in
+10 µ, punctate, the puncta obsolescent, small or interrupted.
+
+Willistown, Pa. Rare.
+
+Pl. 19, Fig. 24.
+
+
+PLEUROSIGMA WM. SM. (1852)
+
+(pleura, a side, and sigma, the letter s)
+
+Valve lanceolate, sigmoid; axial area very narrow, central area small;
+striæ punctate, in transverse and oblique lines.
+
+Cleve divides the forms usually known as Pleurosigma into two genera,
+Pleurosigma and Gyrosigma. Pleurosigma includes all forms having oblique
+rows of puncta, while Gyrosigma includes all having longitudinal rows. Both
+have transverse striæ. The former consists entirely of marine species,
+while in the latter the species are found in fresh, brackish and salt
+water.
+
+The endochrome in Pleurosigma, according to Mueller, consists of two bands
+which differ in the median part of each valve. Mereschkowsky says that the
+endochrome is so divided as to form four bands, two on each valve, that
+their position is different in different species, and that they are not the
+same on valves of the same frustule.
+
+Cleve prefers to classify the species of Pleurosigma and Gyrosigma in
+accordance with the outline of the valve and the flexure of the median
+line. I shall, however, retain the method used by Peragallo and Grunow and
+arrange the forms according to the striation.
+
+
+(1) OBLIQUE STRIÆ ABOUT 90 DEGREES, MORE DISTINCT THAN THE TRANSVERSE
+
+PLEUROSIGMA FORMOSUM WM. SM.
+
+Valve elongated, slender, gently sigmoid, acute at the ends; oblique striæ
+crossing each other at about 90 degrees; 10-16 in 10 µ; transverse striæ,
+14-20 in 10 µ (Cleve).
+
+Along the coast.
+
+Pl. 22, Fig. 5.
+
+
+{74}PLEUROSIGMA OBSCURUM WM. SM.
+
+Valve linear, not sigmoid, or scarcely so; ends obtuse, subconical; raphe
+sigmoid, near the margin at the extremities; transverse and oblique striæ
+equidistant, 28 in 10 µ (Wm. Sm.).
+
+Abundant at Greenwich Point, Philadelphia.
+
+Pl. 22, Fig. 4.
+
+
+(2) OBLIQUE STRIÆ CLOSER AT THE ENDS
+
+PLEUROSIGMA NAVICULACEUM BRÉB.
+
+Valve lanceolate, slightly sigmoid at the extremities; raphe strongly
+sigmoid near the margin at the ends; central nodule large, rounded; oblique
+striæ, 13-14 in the middle, closer at the ends; transverse striæ, 18-20 in
+10 µ (Peragallo).
+
+Long Island Sound.
+
+Pl. 22, Fig. 6.
+
+
+PLEUROSIGMA VIRGINIACUM H. L. SMITH
+
+Valve slightly sigmoid, with acute ends; raphe more sigmoid than the valve,
+excentric near the ends; oblique striæ in different directions at the
+centre, 13 in 10 µ, closer and less distinct at the ends; central nodule
+small but prominent because of its thickness, producing by diffraction an
+apparently wide area (somewhat exaggerated in the figure). L. 95 µ, usually
+larger.
+
+_P. affine_ var. _fossilis_ Grun. (Peragallo).
+
+_P. normanii_ var. _fossilis_ Grun. (Cleve).
+
+Common in the blue clay.
+
+Pl. 22, Fig. 8.
+
+
+(3) OBLIQUE STRIÆ 60 DEGREES
+
+PLEUROSIGMA ANGULATUM (QUEKETT) CL.
+
+Valve rhomboidal, with sub-rostrate or produced ends; central nodule
+rhomboidal; raphe central; transverse and oblique striæ at an angle of 60
+degrees, equidistant, 18-22 in 10 µ.
+
+_Navicula angulata_ Quekett.
+
+Along the coast.
+
+Pl. 22, Fig. 3.
+
+
+PLEUROSIGMA STRIGOSUM WM. SM.
+
+Valve lanceolate, with sub-acute, somewhat revolute, apices; oblique striæ
+at an angle of about 60 degrees, otherwise as in angulatum.
+
+Along the coast. Not common.
+
+Pl. 22, Fig. 1.
+
+
+PLEUROSIGMA ÆSTUARII BRÉB.
+
+Valve lanceolate, with produced apices; raphe less sigmoid than the valve
+and excentric; oblique striæ, 19-21 in 10 µ, at an angle of about 60
+degrees.
+
+Along the coast. Common.
+
+Pl. 22, Fig. 7.
+
+
+{75}(4) OBLIQUE STRIÆ 60 DEGREES, THE TRANSVERSE MORE DISTANT
+
+PLEUROSIGMA RIGIDUM WM. SM.
+
+Valve nearly straight or slightly sigmoid, with obtuse ends; raphe central,
+excentric near the ends; oblique striæ, 17-21, transverse, 16-19 in 10 µ.
+(Peragallo).
+
+New Rochelle, N. Y.
+
+Pl. 22, Fig. 2 (very near the var. gigantea Grun.)
+
+
+GYROSIGMA HASSALL (1845)
+
+(gyros, curved, and sigma)
+
+Valve lanceolate, sigmoid; axial area very narrow, central area small;
+striæ punctate, in transverse and longitudinal rows.
+
+Chromatophores two, in long and narrow bands, perforated, differing from
+those of Pleurosigma. The elæoplasts are also arranged differently in the
+two genera. (Mereschkowsky, Études sur l'Endochrome des Diatomées, Imperial
+Academy of Petrograd, 1901, Vol. 11, No. 6, p. 18 et seq.)
+
+The arrangement is according to Peragallo.
+
+
+(1) LONGITUDINAL STRIÆ MORE DISTANT THAN THE TRANSVERSE
+
+GYROSIGMA HIPPOCAMPUS (EHR.)
+
+Valve lanceolate, sigmoid, with obtuse ends; raphe nearly central;
+transverse striæ 15-17, longitudinal, 10-12 in 10 µ.
+
+_Navicula hippocampus_ Ehr.
+
+_Pleurosigma hippocampus_ (Ehr.) Wm. Sm.
+
+_Gyrosigma attenuatum_ (Kuetz.) Cl.
+
+Long Island Sound.
+
+Pl. 23, Fig. 3.
+
+
+(2) LONGITUDINAL AND TRANSVERSE STRIÆ NEARLY EQUAL
+
+GYROSIGMA BALTICUM (EHR.) CL.
+
+Valve with margins parallel nearly to the extremities, which are suddenly
+unilaterally sub-conical and obtuse; raphe sigmoid; transverse and
+longitudinal striæ nearly equally distant, 15 in 10 µ (Per.). L. 200-360 µ.
+
+_Navicula baltica_ Ehr.
+
+_Pleurosigma balticum_ (Ehr.) Wm. Sm.
+
+Common along the coast.
+
+Pl. 23, Fig. 2.
+
+
+GYROSIGMA PARKERI VAR. STAURONEIOIDES GRUN.
+
+Valve lanceolate, slightly sigmoid, ends produced into beaks with sub-acute
+apices; raphe straight in the middle part; central nodule elliptical;
+transverse striæ, 21, and longitudinal, 24 in 10 µ (Per.).
+
+An apparent stauros, variable in width, extends to the margin and, in
+consequence, the median transverse striæ are more evident. L. 75 µ.
+
+Schuylkill River. Rather rare.
+
+Pl. 23, Fig. 7.
+
+
+{76}GYROSIGMA SIMILE (GRUN.)
+
+Valve slightly sigmoid, broad, with obtuse ends; raphe sigmoid, nearly
+central; transverse striæ, 15, longitudinal, 16-17 in 10 µ (Per.).
+
+_Pleurosigma simile_ Grun.
+
+_Gyrosigma balticum_ var. _similis_ (Grun.) Cl.
+
+Shark River, N. J.
+
+Pl. 23, Fig. 4.
+
+
+(3) TRANSVERSE STRIÆ MORE DISTANT
+
+GYROSIGMA ACUMINATUM (KUETZ.) CL.
+
+Valve sigmoid, tapering to the sub-acute ends; raphe central; transverse
+and longitudinal striæ nearly equally distant, 17 or 18 in 10 µ (Per.).
+
+_Frustulia acuminata_ Kuetz.
+
+Port Penn, Delaware River.
+
+Pl. 23, Fig. 5.
+
+
+GYROSIGMA STRIGILIS (WM. SM.) CL.
+
+Valve sigmoid, with obtuse ends; raphe doubly sigmoid; axial area rather
+wide; transverse striæ, 13, and longitudinal, about 16 in 10 µ.
+
+Long Island Sound. Not common.
+
+Pl. 23, Fig. 1.
+
+
+GYROSIGMA KUETZINGII (GRUN.) CL.
+
+Valve sigmoid, lanceolate, with sub-acute ends; raphe central, the central
+nodule elliptical; transverse striæ, 21-23, and longitudinal, 25-26 in 10
+µ.
+
+_Pleurosigma spencerii_ var. _acutiuscula_ Grun.
+
+_Pleurosigma spencerii_ var. _kuetzingii_ Grun.
+
+Common in fresh water.
+
+Pl. 38, Fig. 12.
+
+
+GYROSIGMA SCALPROIDES (RAB.) CL.
+
+Valve slightly sigmoid, with obtuse ends; raphe nearly straight; central
+nodule elliptical; transverse striæ, 22, slightly radiate and more distant
+in the middle; longitudinal striæ, 29 in 10 µ. L. 60 µ.
+
+Common in streams.
+
+Pl. 38, Fig. 9.
+
+In Pl. 23, Fig. 6 represents a form more sigmoid.
+
+
+GYROSIGMA SPENCERII VAR. NODIFERA GRUN.
+
+Valve sigmoid, with obtuse ends; raphe central; central nodule obliquely
+elongated; transverse striæ, 17-18 in 10 µ, curved in the middle of the
+valve, longitudinal striæ, 22 in 10 µ. L. 150 µ.
+
+Blue clay.
+
+Pl. 23, Fig. 8.
+
+
+GYROSIGMA PROLONGATUM (WM. SM.) CL.
+
+Valve narrow, lanceolate, produced into beaks, curved in a contrary
+direction; raphe central; transverse striæ, 20-21 in 10 µ, longitudinal
+closer. L. 140 µ.
+
+Along the coast, northward.
+
+Pl. 38, Fig. 13.
+
+I have not seen any specimens south of New England, but they will probably
+occur.
+
+
+{77}(4) STRIÆ ALIKE, EXTREMITIES PRODUCED
+
+GYROSIGMA FASCIOLA (EHR.) CL.
+
+Valve lanceolate, attenuated into curved beaks turned in opposite
+directions; raphe central, straight, except at the beaks; transverse striæ,
+22, longitudinal, 24 in 10 µ (Per.).
+
+New York Bay.
+
+Pl. 23, Fig. 9.
+
+
+FRUSTULIA AG. (1824); em. GRUN. (1865)
+
+(frustulum, a small piece)
+
+Valves naviculoid, similar, usually free but sometimes enclosed in
+gelatinous tubes or embedded in mucus. Median line between two thickened
+ribs. Central and terminal nodules frequently elongated. Surface of valve
+with fine puncta in longitudinal and transverse lines appearing hyaline
+under medium powers.
+
+Chromatophores, two, extending along the girdle. They differ from those of
+Navicula in being separated from the wall in the middle by a hemispherical
+mass of protoplasm. According to Pfitzer, each chromatophore is divided in
+the middle, allowing a connection between the hemispherical mass and the
+central plasma mass. Schmitz states that the chromatophore is thickened in
+the middle and contains a pyrenoid.
+
+In conjugation, two frustules form two cylindrical bodies which later
+become conical and from which are formed the sporangial valves twice the
+usual size.
+
+
+FRUSTULIA LEWISIANA (GREV.) DE TONI
+
+Valve elliptical or linear, with rounded ends; terminal nodules elongated,
+at a distance from the ends; striæ, 24 in 10 µ.
+
+Port Penn, Delaware River. Along the coast.
+
+Pl. 17, Fig. 1.
+
+
+FRUSTULIA RHOMBOIDES (EHR.) DE TONI
+
+Valve lanceolate or rhombic-lanceolate, rounded at the ends; central and
+terminal nodules short; striæ, 20 in 10 µ, sometimes coarser.
+
+Common in fresh water.
+
+Pl. 17, Fig. 2.
+
+
+FRUSTULIA RHOMBOIDES VAR. AMPHIPLEUROIDES GRUN.
+
+Valve rhombic-lanceolate; central and terminal nodules elongated; median
+line somewhat excentric.
+
+Blue clay.
+
+Pl. 17, Fig. 3.
+
+
+FRUSTULIA RHOMBOIDES VAR. SAXONICA (RAB.) DE TONI
+
+Valve smaller than in rhomboides, with somewhat produced ends, closer
+median ribs and rounded central nodule.
+
+Fresh water.
+
+Pl. 17, Fig. 6.
+
+
+FRUSTULIA VULGARIS (THWAITES) DE TONI
+
+Valve elliptical-lanceolate, with rounded or sometimes sub-rostrate ends;
+central and terminal nodules slightly elongated; striæ delicate, closer at
+the ends. Frustules at first in gelatinous tubes.
+
+_Colletonema vulgaris_ Thwaites.
+
+Fresh water.
+
+Pl. 17, Fig. 4.
+
+
+{78}FRUSTULIA INTERPOSITA (LEWIS) DE TONI
+
+Valve linear-elliptical, rounded at the ends; terminal nodules short.
+
+_Navicula interposita_ Lewis.
+
+Along the coast. Port Penn, Delaware River.
+
+Pl. 17, Fig. 5.
+
+
+AMPHIPLEURA KUETZ. (1844)
+
+(amphi, on both sides, pleura, a side)
+
+Frustules free, in gelatinous masses or in tubes. Valve linear-lanceolate;
+central nodule narrow, extending half the length of the valve or more, then
+forking toward the ends. Terminal nodules prolonged, as in Frustulia, into
+a "porte-crayon-shaped" figure.
+
+Chromatophores two, very short.
+
+
+AMPHIPLEURA PELLUCIDA KUETZ.
+
+Frustules free or in mucous masses. Valve fusiform; forks about one-fourth
+the length of the valve; striæ transverse, punctate, 36-40 in 10 µ (J. J.
+Woodward).
+
+Occasional in the Delaware River.
+
+Pl. 17, Fig. 9.
+
+
+AMPHIPLEURA RUTILANS (TRENTEPOHL) CL.
+
+Frustules enclosed in gelatinous tubes. Valve linear-lanceolate, obtuse at
+the ends; forks about one-third the length of the valve; striæ, 28 in 10 µ.
+
+_Conferva rutilans_ Trentepohl.
+
+_Schizonema dillwynii_ Wm. Sm.
+
+Abundant at Belmar, N. J.
+
+Pl. 17, Fig. 10.
+
+Fig. 11 represents a portion of the gelatinous tube containing frustules.
+
+
+DICTYONEIS CLEVE (1890)
+
+(dictyon, a net)
+
+Frustules oblong. Valve lanceolate, constricted in the middle (in our
+species); an outer layer finely punctate and an inner layer of
+reticulations; the margin of the valve divided into large, quadrate cells.
+
+The genus Dictyoneis includes species at one time ascribed to Mastogloia
+and Navicula. The structure, however, is not like that of either, as the
+loculi are attached to the valve and are not separable as in Mastogloia,
+and the cell-wall is not like that of any Navicula.
+
+Cleve remarks that Dictyoneis is found in warm waters. Lewis found one
+specimen at Black Rock Harbor, L. I., and one in the Delaware River blue
+clay. The specimens here described I found living on the New Jersey coast.
+
+
+DICTYONEIS MARGINATA VAR. TYPICA CLEVE
+
+Valve panduriform, with cuneate lobes; axial area narrow, linear, scarcely,
+or not at all, widened in the middle; terminal fissures in contrary
+directions; outer stratum finely punctate, about 25 in 10 µ, in parallel
+striæ; inner stratum coarsely reticulated. Four and one-fourth times longer
+than broad; marginal cells, 5 in 10 µ, smaller or obsolescent in the middle
+of the valve; cells of the valve in irregular transverse rows, 10-12 in 10
+µ. L. 93 µ.
+
+_Navicula marginata_ Lewis.
+
+Absecon, N. J.
+
+Pl. 20, Fig. 3.
+
+
+{79}DICTYONEIS MARGINATA VAR. COMMUTATA CLEVE
+
+Valve four and one-half times longer than broad; cells of the valve in
+irregular, transverse rows about 11 in 10 µ; marginal cells nearly equal, 6
+in 10 µ. L. 125 µ.
+
+Absecon, N. J.
+
+Pl. 20, Fig. 2.
+
+
+DICTYONEIS MARGINATA VAR. MAXIMA N. VAR.
+
+Valve with cuneate segments; marginal cells, 4 in 10 µ; cells of the valve,
+5 in 10 µ, obsolescent in the middle and smaller; transverse striæ, 25 in
+10 µ.
+
+Atlantic Coast. Rare.
+
+Pl. 20, Fig. 1 (from a specimen found at Colon).
+
+
+TRACHYNEIS CLEVE (1894)
+
+(trachys, rough, and neis (naus), named from the chief species)
+
+Valve more or less linear or linear-lanceolate. It appears to be composed
+of three strata, one an interior, coarsely dotted, an exterior of fine
+puncta in longitudinal striæ, scarcely visible, and a median of transverse
+anastomosing costæ forming irregular alveoli.
+
+Chromatophores, two or four bands on the zone (Mereschkowsky).
+
+
+TRACHYNEIS ASPERA VAR. INTERMEDIA GRUN.
+
+Valve linear-elliptic; axial area a stauros widened outward and unilateral.
+Striæ of the median layer of radiating rows of oblong alveoli.
+
+Along the coast. Not common.
+
+Pl. 17, Fig. 15.
+
+The type form and its numerous varieties are quite ubiquitous. Very large
+specimens occur in the Antarctic regions, especially in material from Ross
+Island, S. Victoria Land (Shackleton Ant. Exp.).
+
+
+BRÉBISSONIA GRUN. (1860)
+
+(named after Alphonse de Brébisson, the distinguished French naturalist)
+
+Frustules stipitate; valve lanceolate; striæ transverse in the middle,
+radiate at the ends. Median area narrow, central nodule elongated, terminal
+fissures at a distance from the ends. Valve with an outer finely punctate
+stratum.
+
+At one end of one valve in each frustule is found a conspicuous punctum,
+the plasma pore of Otto Mueller, through which the frustule is connected
+with the gelatinous stipe, analogous to the pore in Diatoma connecting the
+zig-zag frustules.
+
+Chromatophore single, lying on one girdle and passing over to each valve.
+
+
+BRÉBISSONIA BOECKII (KUETZ.) GRUN.
+
+Valve lanceolate, with sub-acute apices; striæ, 3-4 in 10 µ, not reaching
+the median line.
+
+Blue clay. Very rare. Common in brackish water at Chestertown, Md. (T. C.
+Palmer)
+
+Pl. 17, Fig. 7.
+
+
+{80}BRÉBISSONIA PALMERII, N. SP.
+
+Valve rhombic-lanceolate, with cuneate ends and produced apices. Central
+nodule more elongate and terminal fissures further from the ends than in B.
+boeckii.
+
+Pavonia, N. J. (artesian well, depth of 40 ft.). Rare.
+
+Pl. 17, Fig. 8.
+
+I take pleasure in naming this species after Mr. T. Chalkley Palmer, of
+Media, Pa., the author of numerous papers on the Diatomaceæ.
+
+Lewis partly describes a similar form, which he does not name, as a species
+of Navicula found in the blue clay at Kaighn's Point, N. J. (Lewis, "New
+and Intermediate Forms," etc., p. 15, Pl. 1, Fig. 8.)
+
+
+ANOMOEONEIS PFITZER (1871)
+
+(anomoios, unlike, and neis (naus), a boat)
+
+Valve lanceolate, axial area narrow, central area widened; transverse striæ
+punctate, the puncta in longitudinal rows or interrupted by blank lines.
+
+A single chromatophore lies along one of the girdle sides and extends over
+the valves, each of the two parts being deeply notched or slit at the ends.
+According to Schmitz there are two pyrenoids, but Heinzerling thinks there
+is but one.
+
+Cleve considers this genus not well founded, as it is based upon the cell
+contents of but one species, the structure of the other species not being
+known. As the forms here described are easily recognized by the interrupted
+puncta, the genus is, at least, convenient.
+
+
+ANOMOEONEIS SPHÆROPHORA (KUETZ.) CL.
+
+Valve elliptic-lanceolate, ends rostrate-capitate. Axial area narrow,
+central area rounded, larger on one side of the median line than the other.
+Striæ very slightly radiate, 16 in 10 µ, punctate, the puncta interrupted
+by longitudinal blank lines.
+
+Pfitzer states that the central plasma mass is unequal on the two sides.
+
+_Navicula sphærophora_ Kuetz.
+
+Fresh and brackish water. Not common.
+
+Pl. 40, Fig. 2.
+
+
+ANOMOEONEIS SERIANS (BRÉB.) CL.
+
+Valve lanceolate, acute; axial area lanceolate; striæ, 24 in 10 µ; puncta
+elongate.
+
+Not common in this locality, but abundant northwards; fossil in the peat
+deposits of New England.
+
+May's Landing, N. J.
+
+Pl. 17, Fig. 12.
+
+Forma minor--Valve rhombic-lanceolate, smaller than the type.
+
+May's Landing, N. J.
+
+Pl. 17, Fig. 13.
+
+
+ANOMOEONEIS FOLLIS (EHR.) CL.
+
+Valve rhomboid, tumid in the middle and obtuse at the produced ends.
+Central area lanceolate; striæ radiate in the middle, transverse at the
+ends.
+
+_Navicula follis_ Ehr.
+
+_Navicula trochus_ Kuetz.
+
+{81}Reported by Lewis as very rare in the blue clay of the Delaware River.
+I have not seen it in this locality. The figure is drawn from a specimen in
+the W. Bridgewater, Mass., deposit.
+
+Pl. 17, Fig. 14.
+
+
+CALONEIS CLEVE (1894)
+
+(calos, beautiful)
+
+Valve convex, linear or lanceolate in general outline, with transverse,
+smooth or finely punctate striæ crossed by one or more longitudinal lines.
+
+Endochrome of two chromatophores lying one on each valve, entire in some
+species and deeply cleft in others.
+
+
+CALONEIS LIBER (WM. SM.) CL.
+
+Valve linear, with parallel margins and rounded ends; axial area narrow,
+central area orbicular; striæ transverse in the middle, slightly divergent
+at the ends, 16 in 10 µ; terminal fissures slightly curved in the same
+direction; longitudinal line median. L. 82 µ.
+
+Atlantic coast, chiefly southward.
+
+Pl. 40, Fig. 1.
+
+
+CALONEIS SILICULA (EHR.) CL.
+
+Valve linear, gibbous in the middle, with broad sub-cuneate ends; axial
+area narrow, central area rounded; longitudinal line marginal; striæ
+parallel or nearly so, 16 to 18 in 10 µ.
+
+_Navicula silicula_ Ehr.
+
+_Navicula limosa_ Donk.
+
+Blue clay.
+
+Pl. 21, Fig. 3 (var. genuina Cl.).
+
+
+CALONEIS SILICULA VAR. INFLATA (GRUN.) CL.
+
+Valve gibbous in the middle, with rounded ends; central area elliptical.
+
+Schuylkill River.
+
+Pl. 21, Fig. 4.
+
+C. silicula may be recognized by its yellow color when dry. Its varieties
+are extremely numerous.
+
+
+CALONEIS TRINODIS (LEWIS)
+
+Valve divided into three segments of equal width; ends cuneate and usually
+produced; axial area elliptical with a lunate marking on each side; striæ
+radiate in the middle, elsewhere parallel, about 20 in 10 µ, finely
+punctate; longitudinal line marginal, scarcely visible; the striæ become
+fainter toward the axial area.
+
+Occasional in streams and in the blue clay. Abundant in a water-trough at
+Ashbourne, Pa.
+
+Pl. 21, Fig. 8.
+
+I have retained Lewis' name as specific. Lewis, wrongly, I think, ascribes
+his species to _Navicula trinodis_ Wm. Sm., which is not figured by Smith,
+but is illustrated by Van Heurck (Syn. Pl. 14, Fig. 31a), and is named by
+Cleve _Navicula contenta_ var. _biceps_ Arnott. {82}De Toni includes Lewis'
+name under _Rhoiconeis trinodis_ (Wm. Sm.) Grun. Rhoiconeis is
+achnanthiform, with frustules arcuate, and the species is named by Cleve
+_Achnanthes trinodis_ (Arnott). _Caloneis schumanniana_ (Grun.) Cl., to
+which as a variety Cleve unites Lewis' form, appears to resemble it only in
+the lunate marks.
+
+Fig. 9 represents a single specimen found in the Pavonia deposit and which
+I believe to be an abnormal form of C. trinodis, differing only in the
+degree of inflation and in the larger central area.
+
+_Navicula trinodis_ var. _inflata_ Schultze, from Staten Island, is the
+same form figured by Lewis, who states that certain specimens have produced
+apices.
+
+
+CALONEIS PERMAGNA (BAIL.) CL.
+
+Valve lanceolate, with produced apices; median line nearly straight; axial
+area lanceolate, irregular or slightly unilateral, about half the width of
+the valve; striæ, 9 in 10 µ, radiate and indistinctly punctate;
+longitudinal lines double. L. 100-200 µ.
+
+_Pinnularia permagna_ Bail.
+
+Common in brackish water.
+
+Pl. 21, Fig. 1.
+
+
+CALONEIS PERMAGNA VAR. LEWISIANA N. VAR.
+
+Valve lanceolate, with undulating sides and sub-cuneate apices; axial area
+less than one-third the width of the valve; striæ radiate, 12 in 10 µ,
+indistinctly punctate; longitudinal lines double, closer together than in
+the type. L. 140 µ.
+
+Lewis illustrates this variety in "New and Rare Species," Pl. 2, Fig. 11,
+and states that it is probably Navicula esox Kuetzing. This is an error, as
+Kuetzing's species is Pinnularia esox Ehr., a form near P. major.
+
+Rather common in the Delaware River.
+
+Pl. 21, Fig. 2.
+
+
+CALONEIS FORMOSA (GREG.) CL.
+
+Valve lanceolate, with sub-cuneate apices; axial area one-fourth to
+one-fifth the width of the valve, somewhat unilateral, dilated in the
+middle; striæ, 12-14 in 10 µ radiate, punctate; longitudinal lines double,
+distinct. Variable in size and outline.
+
+Abundant along the shores of the Delaware River.
+
+Pl. 21, Fig. 18.
+
+
+CALONEIS BREVIS VAR. VEXANS (GRUN.) CL.
+
+Valve elliptical-lanceolate; apices obtuse; median fissures distant; axial
+area narrow; central area large, orbicular; longitudinal lines close
+together, median.
+
+Shark River, N. J.
+
+Pl. 21, Fig. 5.
+
+
+CALONEIS WARDII CL.
+
+Valve linear, ends cuneate; axial area linear; central area dilated to a
+stauros reaching the margin; striæ parallel, radiate at the ends, 18 in 10
+µ; longitudinal lines marginal.
+
+Not uncommon in the Delaware River.
+
+Pl. 21, Figs. 6 and 7.
+
+
+{83}CALONEIS POWELLII (LEWIS) CL.
+
+Valve linear, with cuneate ends; axial area linear; central area large,
+quadrate, united to the wide longitudinal lines; striæ parallel, smooth, 8
+in 10 µ.
+
+Long Island (Lewis); Smith's Island, Delaware River.
+
+Pl. 21, Fig. 10.
+
+
+NEIDIUM PFITZER (1871)
+
+(neidion, dim. of naus, a boat)
+
+Valve linear or lanceolate; median fissures turned in opposite directions,
+terminal fissures appearing bifurcate (?); striæ transverse, usually
+oblique, finely punctate, crossed by one or several longitudinal blank
+lines.
+
+Chromatophores, two, lying on the girdle side, in cell division each
+forming a partially divided pair. A large pyrenoid is said to be found in
+the middle of each chromatophore, but Mereschkowsky states that the
+pyrenoids are absent, but that in N. affine four elæoplasts are always seen
+in the centre of the frustule.
+
+A genus easily recognized by the peculiar terminal and median fissures and
+by the yellowish or brownish color of the valves when dry, darker than in
+Caloneis.
+
+
+NEIDIUM AFFINE (EHR.) PFITZER
+
+Valve linear, with protracted, sub-rostrate or capitate ends.
+
+_Navicula affinis_ Ehr.
+
+
+NEIDIUM AFFINE VAR. GENUINA FORMA MAXIMA CL.
+
+Striæ, 14 in 10 µ, punctate, oblique in the middle, convergent at the ends;
+puncta, 15 in 10 µ. L. 238 µ.
+
+Pensauken, N. J. (artesian well).
+
+Pl. 21, Fig. 11.
+
+Var. genuina forma minor Cl.--L. 26 µ; striæ, 24 in 10 µ.
+
+Brandywine Creek.
+
+Pl. 21, Fig. 12.
+
+
+NEIDIUM AFFINE VAR. AMPHIRHYNCUS (EHR.) CL.
+
+Valve linear, with protracted capitate ends; striæ transverse, interrupted
+by several longitudinal lines.
+
+Willistown, Pa.
+
+Pl. 21, Fig. 13.
+
+
+NEIDIUM AMPHIGOMPHUS (EHR.) PFITZER
+
+Valve with parallel margins and cuneate ends; striæ transverse, interrupted
+by several longitudinal lines; central area widened transversely.
+
+_Navicula amphigomphus_ Ehr.
+
+Wissahickon.
+
+Pl. 21, Fig. 14.
+
+
+NEIDIUM PRODUCTUM (WM. SM.) CL.
+
+Valve linear, elongate, with capitate apices; striæ slightly oblique;
+longitudinal lines marginal; axial area very narrow, central area small.
+
+_Navicula producta_ Wm. Sm.
+
+Newtown Square.
+
+Pl. 21, Fig. 16.
+
+
+{84}NEIDIUM IRIDIS (EHR.) CL.
+
+Valve linear or lanceolate-elliptical, with sub-cuneate or rounded ends;
+striæ oblique, about 18 in 10 µ; central area orbicular.
+
+_Navicula iridis_ Ehr.
+
+_Navicula firma_ Kuetz.
+
+Willistown, Pa.; Middletown, Delaware Co., Pa. (Palmer).
+
+Pl. 21, Fig. 17.
+
+The form here figured is probably the variety ampliata (Ehr.) Cl. with less
+acute apices and more elliptical outline. The species occurs in many
+variations, the larger being found northward, especially in the peat
+deposits of New England.
+
+
+NEIDIUM HITCHCOCKII (EHR.) CL.
+
+Valve linear, with triundulate margin and cuneate ends; striæ transverse,
+oblique.
+
+_Navicula hitchcockii_ Ehr.
+
+Pavonia, N. J. (artesian well); Kirkwood Pond, N. J.
+
+Pl. 21, Fig. 15.
+
+
+DIPLONEIS EHR. (1840)
+
+(diplos, double)
+
+Valve elliptical or panduriform; median line enclosed in strongly siliceous
+horns corresponding to the lyre-shaped areas of Navicula lyra but never
+punctate; central nodule, quadrate; valve costate, or striate, or both;
+between the horns and the outer part are thinner spaces or sulci, and, in
+some species, outside of the sulci are narrow spaces known as lunulæ.
+
+Chromatophores, two, upon the girdle or the valves. Pyrenoids have been
+found in one species only, D. interrupta.
+
+
+DIPLONEIS ELLIPTICA (KUETZ.) CL.
+
+Valve elliptical; central nodule large; sulci narrow, curved, close to the
+horns; striæ punctate, in rows radiating more and more toward the ends.
+Variable in size and in the coarseness of puncta which are from 10 to 13 in
+10 µ (Cleve).
+
+Cleve describes D. ovalis Hilse as having the central nodule rounded, but
+otherwise about the same as D. elliptica, and as equivalent to Navicula
+ovalis A. Schmidt (Atlas, Pl. 7, Figs. 33 to 36).
+
+Very common in fresh water and occasional in brackish.
+
+Pl. 20, Fig. 14.
+
+
+DIPLONEIS SMITHII (BRÉB.) CL.
+
+Valve elliptical; central nodule not broad; furrows evenly curved on the
+outer edge, crossed by costæ and double oblique rows of alveoli. Variable
+in size and in the curvature of the furrows.
+
+Cleve forms a new species, D. major, of the large form figured by Schmidt
+(Atlas, Pl. 7, Figs. 18, 19, 21 and 22), stating that the structure is much
+coarser and the form is larger with broad furrows. In the specimen here
+figured the size is median and the furrows are as in D. major.
+
+Marine and brackish. Common.
+
+Pl. 20, Fig. 17.
+
+
+{85}DIPLONEIS CRABRO VAR. PANDURA (BRÉB.) CL.
+
+Valve constricted, segments tongue-shaped; central nodule small; horns
+narrow, nearly parallel, with a row of large puncta; costæ, 4 in 10 µ,
+convergent in the middle, radiating at the ends, alternating with a double
+row of puncta, 11 in 10 µ.
+
+Pavonia, N. J. (artesian well).
+
+Pl. 20, Fig. 4.
+
+
+DIPLONEIS CRABRO VAR. EXPLETA (A. S.) CL.
+
+Valve slightly constricted, segments tongue-shaped; costæ robust, 5 or 6 in
+10 µ, alternating with double rows of rather coarse puncta. L. 56 µ.
+
+Port Penn, Delaware River.
+
+Pl. 20, Fig. 15.
+
+
+DIPLONEIS CRABRO VAR. PANDURELLA CL.?
+
+Valve constricted, the lobes elliptical; central nodule large, with horns
+parallel in the middle, convergent at the ends; furrows wide, with faint
+costæ; no lunula; costæ parallel in the middle, radiate at the ends, 9 in
+10 µ, alternating with very fine double rows of puncta (not shown in the
+figure). L. 65 µ.
+
+Blue clay.
+
+Pl. 20, Fig. 13.
+
+
+DIPLONEIS CRABRO VAR.?
+
+Valve constricted, segments elliptical; costæ, 8 in 10 µ, converging in the
+middle, radiating at the ends; horns narrow; furrows wide, costate; lunulæ
+indistinct. L. 75 µ.
+
+Resembles var. pandurella except in the convergence of the costæ and in the
+lunula.
+
+Squan River. Marine.
+
+Pl. 20, Fig. 9.
+
+
+DIPLONEIS FUSCA VAR. DELICATA (A. S.) CL.
+
+Valve elliptical; furrows broad, crossed with rows of faint costæ and
+alveoli; costæ, 6 or 7 in 10 µ; alveoli, 10 in 10 µ, in short, irregular,
+longitudinal rows. L. 84 µ.
+
+Port Penn, Delaware River.
+
+Pl. 20, Fig. 11.
+
+
+DIPLONEIS GRUENDLERI (A. S.) CL.
+
+Valve constricted, segments tongue-shaped, often unequal; horns broad,
+divergent in the middle; furrows narrow; costæ transverse, crossed by from
+3 to 7 longitudinal costæ, interrupted in the middle at the border.
+
+Blue clay.
+
+Pl. 20, Figs. 7 and 8.
+
+
+DIPLONEIS PUELLA (SCHUM.) CL.
+
+Valve elliptical, sometimes orbicular; furrows very narrow; striæ, 20 in 10
+µ, indistinct. L. 15 µ.
+
+_Diploneis elliptica_ var. _minutissima_ Grun.
+
+Shark River, N. J. Brackish.
+
+Pl. 20, Fig. 12.
+
+
+DIPLONEIS EXCENTRICA, N. SP.
+
+Valve elliptical; central nodule quadrate; furrows of the same width
+throughout, nearly parallel; costæ radiating toward the ends, 10 in 10 µ,
+indistinct on the furrows, alternating with alveoli, 7 in 10 µ, in
+irregular, longitudinal lines. One side of the valve is one and a half
+times the width of the other. L. 49 µ.
+
+{86}I can find neither description nor figure of any species to which I can
+ascribe this form. It approaches D. elliptica. The alveoli are quite
+distinct and distant from each other.
+
+Brackish water. Very abundant in a gathering from Squan River, N. J.
+
+Pl. 20, Fig. 10.
+
+
+DIPLONEIS OCULATA (BRÉB.) CL.
+
+Valve elliptical; striæ radiate at the ends, about 20 in 10 µ, coarsely
+punctate. L. 23 µ.
+
+Fresh water.
+
+Pl. 26, Fig. 7.
+
+The figure is drawn from Brébisson's original material in H. L. Smith's
+Type Slide No. 299.
+
+_Navicula oculata_ Bréb.
+
+Reported from New Jersey. I have not seen this species in this locality.
+Navicula oculata, referred to by Kain as occurring in Shark River, is not
+this form.
+
+
+DIPLONEIS GEMMATA (GREV.) CL.
+
+Valve oblong-linear, with cuneate ends and parallel or slightly concave
+sides; central nodule large; horns parallel; furrows about one-third the
+width of the valve. Costæ about 5 in 10 µ, alternating with double rows of
+fine puncta; short costæ occur along the borders of the horns.
+
+Port Penn, Delaware River.
+
+Pl. 20, Fig. 16.
+
+
+DIPLONEIS CAMPYLODISCUS (GRUN.) CL.
+
+Valve suborbicular; central nodule quadrate; horns divergent; costæ, 6 in
+10 µ, alternating with double rows of alveoli; furrows broad, costate near
+the horns.
+
+Differs from Cleve's description in having 6, instead of 4, costæ in 10 µ.
+
+Pensauken, N. J. (artesian well). Rare.
+
+Pl. 20, Fig. 6.
+
+
+MASTOGLOIA THWAITES (1856)
+
+(mastos, a breast, and gloios, gelatinous, referring to the "mamillate
+cushion" in which the frustules are often immersed)
+
+Frustule rectangular. Valves similar, naviculoid. Central and axial areas
+usually narrow or indistinct; striæ punctate, parallel in the middle. On
+each side, between the valve and the zone, is a septate plate.
+
+
+ANALYSIS OF SPECIES
+
+
+  Striæ interrupted by a hyaline furrow on each side of
+    the median line                                           kinsmanii
+
+  Striæ not interrupted:
+
+    Loculi, five, or less                                     exigua
+
+          more than five, equal, ending at distance from
+             the ends                                         smithii
+
+            ending near the ends, distinct                    lanceolata
+
+                                  indistinct                  elegans
+
+            very numerous                                     apiculata
+
+            unequal                                           angulata
+
+{87}Karsten states that there are two chromatophores, each of which extends
+from the middle of one valve to the end and down the middle of the other
+valve. Mereschkowsky says, however, that there are four plates or
+chromatophores, sometimes on the valve, sometimes on the zone, according to
+the species, and that two long pyrenoids unite the two opposite
+chromatophores.
+
+
+MASTOGLOIA KINSMANII LEWIS
+
+Valve lanceolate-elliptical, with sub-rostrate ends; loculi more numerous
+than in M. angulata but less than in M. apiculata, the middle ones larger.
+Median line with a sulcus on each side; central area quadrate.
+
+_Mastogloia braunii_ Grun. (According to Cleve).
+
+Atlantic City.
+
+Pl. 17, Fig. 16.
+
+
+MASTOGLOIA EXIGUA LEWIS
+
+Valve elliptical- or linear-lanceolate; loculi, 2-5, usually 3, larger in
+the middle and rounded; central space small; striæ, 20-24 in 10 µ.
+
+Along the coast.
+
+Pl. 17, Fig. 24.
+
+
+MASTOGLOIA SMITHII THWAITES
+
+Valve lanceolate, sub-rostrate; loculi forming a wide band ending at a
+distance from the ends; striæ transverse, with puncta forming longitudinal
+rows; central area rounded or transversely elliptical.
+
+Along the coast.
+
+Pl. 17, Fig. 19.
+
+
+MASTOGLOIA LANCEOLATA THWAITES
+
+Valve lanceolate, with sub-rostrate apices; loculi very numerous; median
+and central areas indistinct; striæ, 19 in 10 µ, punctate, convergent at
+the ends.
+
+Along the coast.
+
+Pl. 17, Fig. 18.
+
+
+MASTOGLOIA ELEGANS LEWIS
+
+Valve lanceolate, acute; loculi indistinct or rudimentary, extending to the
+ends; central area apparently quadrate, sometimes indistinct; puncta
+distinct, 15 in 10 µ, in transverse and longitudinal rows.
+
+Along the coast. Common.
+
+Pl. 17, Fig. 20.
+
+
+MASTOGLOIA APICULATA WM. SM.
+
+Valve elliptical-lanceolate, sometimes with slightly produced apices;
+median line between two ribs; central space very small; loculi numerous;
+puncta in slightly radiating rows and in longitudinal lines.
+
+Along the coast.
+
+Pl. 17, Figs. 21, 22, 23.
+
+
+MASTOGLOIA ANGULATA LEWIS
+
+Valve elliptical, with produced apices; loculi usually less than 12,
+unequal, the larger in the middle; striæ, 12 in 10 µ, puncta in decussating
+rows. "Differs from apiculata in its more broadly elliptical shape, the
+smaller number of its loculi and the angular character of its striation"
+(Lewis).
+
+{88}Considered by Cleve as synonymous with M. apiculata Grun., not Wm.
+Smith, and by De Toni as synonymous with M. apiculata Wm. Sm. In any case,
+M. angulata Lewis is not the same as M. apiculata Wm. Sm., the loculi of
+which are equal.
+
+Atlantic City. H. L. Smith T. S. No. 211.
+
+Pl. 17, Fig. 17.
+
+
+STAURONEIS EHR. (1843)
+
+(stauros, a cross, and neis (naus), a boat)
+
+Frustules free, sometimes geminate; valve as in Navicula but with a
+stauros. Cell contents as in Navicula. Mereschkowsky, however, says that
+the chromatophores always contain more pyrenoids than are found in
+Navicula. Heinzerling gives the number as two to four in each
+chromatophore.
+
+Cleve includes under Naviculæ Microstigmaticæ all species of Stauroneis,
+Pleurostauron, Schizostauron, certain Schizonemæ and Naviculæ. As a matter
+of convenience, and because I have already included certain Schizonemæ and
+Scoliopleura under Navicula, and because of the small number of species in
+our locality, I have arranged them under the three divisions of Cleve as
+follows:
+
+_Stauroneis._--Forms having a true stauros, without diaphragms.
+
+_Pleurostauron._--Forms like Stauroneis but with diaphragms at the ends.
+
+_Schizostauron._--Forms having a bifid stauros.
+
+
+STAURONEIS PHOENICENTERON EHR.
+
+Valve lanceolate, obtuse; striæ radiate, 18 in 10 µ, distinctly punctate.
+L. usually 125 µ but sometimes 200 µ.
+
+Common in fresh water.
+
+Pl. 27, Fig. 1.
+
+
+STAURONEIS ANCEPS EHR.
+
+Valve lanceolate, with rostrate or capitate ends; stauros in some cases
+does not reach the margin. The varieties are very numerous.
+
+_Var. gracilis (Ehr.) Cl._--Valve lanceolate, striæ very fine; margin of
+stauros striated. L. 100 µ. Cape May, N. J. Pl. 27, Fig. 5.
+
+_Var. amphicephala (Kuetz.) Cl._--Valve capitate at the ends; striæ, 24 in
+10 µ. L. 47 µ. Fresh water. Pl. 27, Fig. 7.
+
+_Var. ?_--Valve with produced ends; striæ, 30 or more in 10 µ. L. 104 µ.
+Willistown, Pa. Pl. 27, Fig. 4.
+
+_Var. ?_--Valve with produced ends; striæ, about 28 in 10 µ, punctate. L.
+47 µ. Newtown Square. Pl. 27, Fig. 8.
+
+_Var. ?_--Valve with produced ends; striæ, 22 in 10 µ, showing a tendency
+to form longitudinal rows of puncta as in Stauroneis stodderi Greenleaf,
+but the rows are not so evident. L. 60 µ. Pavonia, N. J., artesian well.
+Pl. 27, Fig. 9.
+
+
+STAURONEIS FRICKEI VAR. ANGUSTA N. VAR.
+
+Valve lanceolate, gradually tapering to the obtuse ends; terminal fissures
+prominent, forking at a distance of 7 µ from the ends. Frustules frequently
+geminate. L. 173 µ.
+
+Newtown Square. Rare.
+
+Pl. 26, Fig. 18.
+
+Near Stauroneis frickei A. S. (Atlas, Pl. 242, Fig. 16), except that the
+stauros is narrow at the margin.
+
+
+{89}STAURONEIS SALINA WM. SM.
+
+Valve lanceolate, obtuse; stauros narrow, with short, scattered striæ at
+the margin, 18 in 10 µ, punctate. L. 65 µ.
+
+Along the coast. Common.
+
+Pl. 27, Fig. 6.
+
+
+STAURONEIS LEGUMEN EHR.
+
+Valve elliptical-lanceolate, inflated in the middle, with produced
+sub-capitate or rostrate ends separated by diaphragms. Stauros wide,
+striated at the margins; axial area very narrow; striæ radiate, about 26
+(?) in 10 µ, punctate. L. 28 µ.
+
+Pavonia, N. J., artesian well.
+
+Pl. 39, Fig. 15.
+
+In Cleve's description and Van Heurck's figure, the median inflation is
+"not larger than the others." In the present form the median inflation is
+wider.
+
+
+STAURONEIS ACUTA WM. SM.
+
+Valve rhombic-lanceolate, obtuse; a diaphragm at each end; stauros widened
+outwards; striæ, 15 or 16 in 10 µ, punctate. L. 130 µ.
+
+Blue clay.
+
+Pl. 27, Fig. 2.
+
+
+STAURONEIS AMERICANA A. S.
+
+Valve elliptical-lanceolate, obtuse; striæ, 14 in 10 µ. L. 119 µ.
+
+Pavonia, N. J., artesian well. Rare.
+
+The only specimen found is asymmetrical with respect to the transverse
+axis.
+
+On Plate 40, Fig. 4, is illustrated an abnormal form of Stauroneis,
+apparently near S. acuta, having an elongated central nodule and radiating,
+curved and coarsely punctate striæ. Blue clay.
+
+
+STAURONEIS SMITHII GRUN.
+
+Valve lanceolate, inflated in the middle and at the ends, which have
+diaphragms and are produced into rostrate apices; stauros reaching the
+margin; striæ parallel, about 25 in 10 µ (28 to 30, Cleve), distinctly
+punctate.
+
+Not uncommon in meadow pools near Newtown Square.
+
+Pl. 27, Fig. 11.
+
+
+STAURONEIS CRUCICULA (GRUN.) CL.
+
+Valve lanceolate, with obtuse, produced ends; stauros bifid; striæ, 24 in
+10 µ, oblique, parallel to the branches of the stauros, closer at the ends,
+punctate. L. 32 µ.
+
+Newtown Square. East Park Reservoir. Rare.
+
+Pl. 27, Fig. 10.
+
+
+NAVICULA BORY (1826)
+
+(dim. of navis, a boat)
+
+Valve linear to elliptical; ends acute, rounded, rostrate, capitate or
+truncate; axial area usually distinct; central area distinct, rounded or
+rarely extended into a transverse fascia; striæ transverse or radiate,
+punctate; central area not dilated into a transverse stauros nor into
+horns.
+
+{90}The endochrome in the greater number of species consists of two
+chromatophores extending along the zone and sometimes partly over the
+valves. Sometimes, however, as in N. hennedyi, N. lyra and N. humerosa, the
+bands are on the valves. Certain species have four bands, others eight, and
+in one the endochrome is granular. (Mereschkowsky, l. c., p. 9 et seq.)
+Pyrenoids are usually absent. On account of the diversity of the
+chromatophores, Mereschkowsky considers the genus not homogeneous. The
+difficulty of arranging groups according to the cell contents, however, is
+so great that, for the present, the species must be described by the usual
+characteristics of the valves and divided as follows, according to Cleve,
+to the extent of employing the classification of all Naviculoid forms as
+applicable, especially to the species of Navicula. Van Heurck's analysis
+includes Pinnularia, Trachyneis, Diploneis, Caloneis, Neidium and
+Anomoeoneis, which are here separated, while N. lyra and N. hennedyi are
+placed in different groups, although they are closely related. In other
+respects Cleve's divisions correspond, to some extent, to those of Van
+Heurck.
+
+The genus Navicula at one time included the following: Dictyoneis,
+Pleurosigma, Gyrosigma, Caloneis, Neidium, Diploneis, Frustulia,
+Trachyneis, Anomoeoneis, Pinnularia and Stauroneis, and few forms with a
+raphe escaped. For this reason the diagnosis of the present genus is
+somewhat limited. Pleurosigma and Gyrosigma differ from Navicula in their
+outline, Dictyoneis in the double stratification, Caloneis in the marginal
+lines, Neidium in the median and terminal fissures, Diploneis in the horns,
+Frustulia in the terminal nodules, Trachyneis in the stratification of the
+valve, Anomoeoneis in the longitudinal arrangement of the puncta,
+Pinnularia in the smooth costæ and Stauroneis in the stauros.
+
+As the object of the present work is to aid the student of local forms in
+the identification of species by the briefest methods, the further
+discussion of the reasons for classification will be left for his
+gratification in referring to the authorities on the subject.
+
+
+PUNCTATÆ CLEVE
+
+Valve elliptical to lanceolate; central nodule not stauroid or continued
+into lyriform spaces; striæ distinctly or coarsely punctate, in radiate
+rows.
+
+
+NAVICULA MACULATA (BAIL.) CL.
+
+Valve lanceolate-elliptical, with produced or sub-rostrate ends; axial area
+narrow, wider near the ends and dilated to a rounded, transverse central
+area; striæ radiate, 6 in 10 µ, puncta, 7 in 10 µ, in irregular,
+longitudinal rows. L. 90 to 120 µ (Cl.).
+
+_Stauroneis maculata_ Bail.
+
+_Navicula fischeri_ A. S.
+
+Blue clay. Along the coast, especially southward.
+
+Pl. 24, Fig. 1.
+
+
+NAVICULA LATISSIMA GREG.
+
+Valve oblong-elliptical or elliptical-lanceolate, with sub-cuneate ends;
+axial area lanceolate, widened in the middle to an orbicular space; striæ
+radiate, 7 in 10 µ, puncta, 11 in 10 µ, the median striæ alternating with
+short striæ along the sides. L. 50-150 µ (Cl).
+
+Blue clay. Pavonia, N. J., artesian well.
+
+Pl. 24, Fig. 3.
+
+
+{91}NAVICULA LATISSIMA VAR. ELONGATA (PANT.) CL.
+
+Valve elliptical-lanceolate, with rounded ends; striæ and puncta closer
+than in the type form; axial area narrow, widened in the middle; terminal
+fissures hook-shaped, turned in different directions.
+
+_Navicula humerosa_ var. _elongata_ Pant.
+
+Fossil at Buckshutem, N. J.
+
+Pl. 24, Fig. 5.
+
+
+NAVICULA FUCHSII PANT.
+
+Valve elliptical, with slightly produced apices; axial area wide,
+lanceolate; central area orbicular; striæ alternately longer and shorter in
+the middle, 10-12 in 10 µ; puncta on the border of the axial area larger,
+elongated; median fissures incrassate.
+
+_Navicula humerosa_ var. _fuchsii_ (Pant.) Cl.
+
+_Navicula_ (_latissima_ var.?) _fuchsii_ Pant.
+
+Port Penn, Delaware River.
+
+Pl. 24, Fig. 6.
+
+
+NAVICULA HUMEROSA BRÉB.
+
+Valve lanceolate-elliptical or oblong-elliptical, with sub-cuneate or
+sub-rostrate ends; axial area narrow, lanceolate; central area rounded,
+somewhat transverse; terminal fissures hook-shaped, in the same direction;
+central pores incrassate; striæ, 11 in 10 µ, the middle alternately longer
+and shorter, closer at the ends. L. 60-86 µ. Variable in size, outline and
+fineness of striation.
+
+N. monilifera Cleve (N. granulata Bréb.) differs in having coarser striæ.
+
+Blue clay. Along the coast.
+
+Pl. 25, Fig. 5.
+
+
+NAVICULA PUSILLA WM. SM.
+
+Valve ovate-elliptical, with rostrate or sub-rostrate ends; axial area
+narrow; central area elliptical; striæ radiate, 10-12 in 10 µ in the middle
+where they are longer and shorter alternately, closer at the ends; median
+fissures somewhat incrassate, terminal in the same direction. L. 47 µ.
+
+Smith's Island, Delaware River.
+
+Pl. 25, Figs. 4, 6?
+
+Cleve gives the striæ as 13-18 in the typical form, and 11-13 in varieties.
+In the form here figured the striation is as stated by De Toni, but is
+about 19 at the ends.
+
+Fig. 6 appears to be a small form of N. pusilla, near lanceolata Grun., at
+least according to the figure in "Arctic Diatoms," but not Gregory's
+figure. It occurs rarely in fresh water at Newtown Square. It may be a
+small form of N. punctulata and, if so, is probably accidental, as the
+material is entirely fresh-water.
+
+
+NAVICULA PUSILLA VAR. SUBCAPITATA N. VAR.
+
+Valve elliptical with rostrate-capitate and truncate ends; striæ about 12
+in 10 µ in the middle where they are unequal; axial area narrow, slightly
+widened in the middle; central pores incrassate, terminal fissures in the
+same direction. Differs from type in outline and centre.
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 25, Fig. 8.
+
+
+{92}NAVICULA DELAWARENSIS GRUN.
+
+Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow,
+lanceolate, widened in the middle; striæ about 10 in 10 µ; in the middle,
+much closer at the ends; puncta in the middle, 9 in 10 µ, closer and much
+smaller at the ends. L. 58-95 µ.
+
+Cleve (Le Diatomiste, Vol. 2, p. 14) states that this form is very near N.
+pusilla but is much larger. Specimens from Smith's Island measure 58-65 µ,
+from Wildwood, 95 µ in length.
+
+Pl. 25, Fig. 3.
+
+
+NAVICULA PUNCTULATA WM. SM.
+
+Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow,
+central area rounded; striæ, 11 in 10 µ, closer at the ends, a few shorter
+in the middle; puncta, 10 in 10 µ. L. 54 µ.
+
+_Navicula marina_ Ralfs.
+
+Port Penn, Delaware River (brackish water).
+
+Pl. 25, Fig. 9.
+
+"Although this species is described as marine in the Synopsis of Prof.
+Smith, I have never found it in purely marine localities" (Donkin).
+
+
+NAVICULA PUNCTATA VAR. ASYMMETRICA LAGERSTEDT
+
+Valve lanceolate, with rostrate ends; axial area narrow, central area
+transverse, irregular; striæ radiate, punctate, 12 in 10 µ. L. 36 µ.
+
+_Navicula amphibola_ Cleve.
+
+Blue clay.
+
+Pl. 27, Fig. 15.
+
+
+NAVICULA BRASILIENSIS VAR. BICUNEATA CL., FORMA CONSTRICTA
+
+Valve oblong-elliptical, slightly constricted, with cuneate-rostrate ends;
+axial area narrow; central area dilated transversely and unilaterally;
+striæ, 9 in 10 µ; puncta closer at the border and in irregular longitudinal
+rows in the middle; terminal fissures small, hook-shaped, turned in the
+same direction. L. 93 µ.
+
+Corresponds closely to Cleve's variety except in the constriction.
+
+Blue clay.
+
+Pl. 25, Fig. 2.
+
+
+NAVICULA LACUSTRIS GREG.
+
+Valve lanceolate, sub-acute; axial area narrow; central area orbicular;
+striæ radiate, 14 in 10 µ, punctate, the median puncta sometimes more
+distant than the others.
+
+Blue clay. Rare.
+
+Pl. 27, Fig. 12.
+
+
+LYRATÆ CL.
+
+Valve elliptical or elliptical-lanceolate; striæ punctate, transverse;
+axial area narrow or indistinct; central area expanded on each side into
+lyre-shaped or horn-like blank spaces.
+
+
+NAVICULA PRÆTEXTA EHR.
+
+Valve elliptical; lateral areas not regular, with scattered puncta; striæ
+radiate, 5 or 6 in 10 µ; puncta, 7 or 8 in 10 µ; along the axial area, a
+single or double row of puncta; at {93}the middle of the border, on each
+side, two striæ approach each other closely with a short stria between
+them; terminal fissures small, in the same direction. L. 120 µ.
+
+Port Penn, Delaware River.
+
+Pl. 24, Fig. 2.
+
+While variable in size and striation, approaching N. hennedyi, this
+species, as here figured, is found in the Miocene and later deposits and is
+extant in most parts of the world.
+
+
+NAVICULA IRRORATA GREV.
+
+Valve oblong-elliptical, with cuneate-rostrate ends; striæ, 7 or 8 in 10 µ,
+puncta, 7 in 10 µ; axial area bordered by puncta in unequal, transverse
+rows. L. 84 µ.
+
+Blue clay. Rare.
+
+Pl. 24, Fig. 4.
+
+
+NAVICULA HENNEDYI WM. SM.
+
+Valve elliptical; areas semilanceolate; striæ about 11 in 10 µ, sometimes
+longer and shorter on the margin; short rows of transverse striæ along the
+axial area.
+
+Blue clay.
+
+Pl. 25, Fig. 12.
+
+_Var. circumsecta Grun._--As in the type but with the lateral areas faintly
+striate or punctate.
+
+_Var. manca A. S._--Valve lanceolate-elliptical, the lateral areas narrow
+and convergent toward the ends; short rows of transverse striæ along the
+axial area; striæ, 9 in 10 µ; central pores incrassate.
+
+Blue clay.
+
+Pl. 25, Fig. 11.
+
+
+NAVICULA LYRA EHR.
+
+Valve elliptical, with rounded, sub-rostrate or sub-cuneate ends; lateral
+areas narrow; striæ, 6 to 14 in 10 µ (Cl.), punctate. L. 50-180 µ.
+
+_Var. ehrenbergii Cl._--Lateral areas constricted in the middle, divergent
+at the ends. Cleve refers to Schmidt, Atlas, Pl. 2, Fig. 25, which is not
+divergent at the ends.
+
+Along the coast.
+
+Pl. 25, Fig. 10.
+
+A narrower form occurs which has the areas divergent.
+
+_Var. ?_--Valve elliptical, lateral areas narrow, convergent at the ends
+with short rows of punctate striæ; marginal striæ, 10 in 10 µ, punctate. L.
+60 µ.
+
+Squan River, N. J.
+
+Pl. 20, Fig. 5.
+
+_Var. dilatata A. S._--Valve elliptical, rostrate; lateral areas convergent
+in the middle and nearly parallel or convergent at the ends.
+
+Blue clay.
+
+Pl. 25, Fig. 13.
+
+N. lyra is exceedingly variable in outline, fineness of striation and in
+the lateral areas. Intermediate forms occur approaching N. hennedyi and N.
+spectabilis. In N. hennedyi the lateral areas are broad, semilanceolate,
+not narrowed in the middle. In N. spectabilis the lateral areas are broad
+and narrowed in the middle. In N. lyra the lateral areas are narrow and
+either constricted or not in the middle. In many forms in {94}these three
+species the lateral areas are more or less striated or punctate. Cleve does
+not consider this a distinction of any importance, although certain
+varieties are founded upon it. All three species are very common in the
+blue clay and along the coast, but their varieties are too numerous to
+describe or figure.
+
+
+NAVICULA SPECTABILIS VAR. EMARGINATA CL.
+
+Valve elliptical; lateral areas broad, narrowed in the middle, delicately
+striated; marginal striæ, 10 in 10 µ. L. 70 µ.
+
+Blue clay.
+
+Pl. 25, Fig. 7.
+
+
+NAVICULA PYGMÆA KUETZ.
+
+Valve elliptical, appearing hyaline; axial and central areas faint; lateral
+areas convergent in the middle; striæ indistinct, about 25 in 10 µ. L. 23
+µ.
+
+Brandywine Creek (Palmer).
+
+Pl. 27, Fig. 23.
+
+
+DECUSSATÆ CL.
+
+Valve elliptical or lanceolate; axial area narrow; central area small;
+striæ punctate, in transverse and oblique, curved rows.
+
+
+NAVICULA PLACENTA EHR.
+
+Valve elliptical, with short, rostrate-capitate ends; axial area narrow;
+central area elliptical; striæ in two directions, the transverse about 22
+(to 27, Cl.) in 10 µ, the oblique striæ crossing in both directions in
+curved lines appearing "coarser than the transverse" (Lewis).
+
+A very peculiar species which, as Cleve remarks, seems not to be allied to
+any other. L. about 35 µ, quite constant in size. It is reported from
+Finland, Scotland, Hungary and New Zealand. Dr. Lewis found it in the
+Delaware River. It is occasional in the Schuylkill River and the blue clay,
+and very abundant on Marchantia and mosses on the wet rocks of the upper
+Wissahickon (F. J. Keeley).
+
+Pl. 27, Fig. 17.
+
+
+LINEOLATÆ CL.
+
+Valve more or less lanceolate; axial area narrow or indistinct; striæ
+radiate or parallel, lineate, that is, with the puncta closer than the
+striæ.
+
+
+NAVICULA RADIOSA KUETZ.
+
+Valve lanceolate with sub-rostrate apices; axial area indistinct; central
+area small; striæ radiate in the middle, from 6 to 8 in 10 µ, and
+convergent at the ends, about 12 in 10 µ. L. 47 µ.
+
+Very common in fresh water.
+
+Pl. 26, Fig. 17; Pl. 40, Fig. 9.
+
+
+NAVICULA PEREGRINA EHR.
+
+Valve lanceolate, obtuse; axial area narrow; central area large, rounded or
+slightly irregular; striæ coarse in the middle, 5 in 10 µ, radiate;
+convergent at the ends, 7 or 8 in 10 µ.
+
+Abundant in brackish water. Delaware River.
+
+Pl. 26, Fig. 20.
+
+
+{95}NAVICULA CYPRINUS (WM. SM.)
+
+Valve lanceolate, slightly gibbous in the middle, sub-cuneate at the ends;
+axial area narrow; central area small; striæ radiate in the middle, 10 in
+10 µ, with shorter, transverse striæ intermediate; transverse at the
+extreme ends. L. 82 µ.
+
+_Navicula digito-radiata_ var. _cyprinus_ (Ehr. ?) Wm. Sm. Whether the form
+here figured is Ehrenberg's or not, it is the species known as Pinnularia
+cyprinus Ehr. of Wm. Smith.
+
+Common in Shark River, N. J.
+
+Pl. 26, Fig. 21.
+
+
+NAVICULA REINHARDTII GRUN.
+
+Valve elliptical or elliptical-lanceolate, with broad, rounded ends; axial
+area narrow, widened at the ends to the width of the valve; central area
+widened transversely to an irregular, quadrate space; striæ coarse, 8 in 10
+µ, distinctly lineate, alternately longer and shorter in the middle,
+radiate, nearly transverse at the ends. L. 59 µ.
+
+Blue clay. Rare.
+
+Pl. 26, Fig. 22.
+
+
+NAVICULA LANCEOLATA VAR. ARENARIA (DONK.) CL.
+
+Valve lanceolate; axial area very narrow or indistinct; central area small,
+rounded; striæ radiate, 11 in 10 µ in the middle, closer at the ends. L.
+47-54 µ.
+
+_Navicula arenaria_ Donk.
+
+Shark River, N. J.
+
+Pl. 26, Fig. 23.
+
+
+NAVICULA SALINARUM GRUN.
+
+Valve elliptical-lanceolate with produced sub-capitate or rostrate ends;
+striæ radiate in the middle, longer and shorter; transverse at the ends,
+lineate. L. 32 µ.
+
+Atlantic City, N. J.
+
+Pl. 26, Fig. 24.
+
+
+NAVICULA VIRIDULA VAR. ROSTELLATA KUETZ.
+
+Valve lanceolate with rostrate ends; axial area very narrow, central area
+orbicular; striæ radiate in the middle, about 12 in 10 µ, convergent at the
+ends and closer. L. 43 µ.
+
+Common in fresh water.
+
+Pl. 26, Fig. 16.
+
+
+NAVICULA GRACILIS VAR. SCHIZONEMOIDES (EHR.) V. H.
+
+Valve lanceolate, obtuse; axial area widened in the middle; striæ radiate
+in the middle, about 12 in 10 µ, transverse or slightly convergent at the
+ends. L. 45-60 µ. Occurs in gelatinous tubes; usually found free.
+
+_Colletonema neglectum_ Thwaites.
+
+Fresh water.
+
+Pl. 26, Fig. 19.
+
+
+NAVICULA RAMOSISSIMA (AG.) CL.
+
+Valve lanceolate, sub-acute; axial area very narrow; central area scarcely
+widened; striæ, 12 in 10 µ, parallel throughout. L. 45 µ.
+
+_Micromega ramosissimum_ Ag.
+
+_Schizonema smithii_ Kuetz. (not Ag.).
+
+East River, N. Y.
+
+Pl. 26, Fig. 14.
+
+
+{96}NAVICULA ANGLICA RALFS
+
+Valve elliptical, with sub-capitate or rostrate ends; axial area narrow,
+central area small; striæ radiate, 12-13 in 10 µ, distinctly punctate. L.
+26 µ.
+
+Fresh water.
+
+Pl. 26, Fig. 26.
+
+
+NAVICULA GASTRUM EHR.
+
+Valve elliptical, with rostrate ends; axial area narrow, central area
+transverse or irregular; striæ radiate, 9 in 10 µ in the middle. L. 26 µ.
+
+The form here figured approaches N. anglica.
+
+Kirkwood Pond, N. J.
+
+Pl. 26, Fig. 25.
+
+
+NAVICULA DICEPHALA WM. SM.
+
+Valve linear, with rostrate or rostrate-capitate ends; axial area narrow,
+central area rectangular, transverse; striæ radiate, 12 in 10 µ. L. 32 µ.
+
+Fresh water.
+
+Pl. 27, Fig. 16.
+
+
+NAVICULA HUMILIS DONK.
+
+Valve elliptical, with broad, rostrate ends; axial area narrow; central
+area small; striæ radiate and distant in the middle, convergent at the
+ends, coarse, appearing costate, averaging 9 in 10 µ. L. 19 µ. As Donkin
+states, the striæ are "very conspicuous."
+
+_Navicula hungarica_ var. _capitata_ (Ehr.) Cl.
+
+_Navicula globiceps_ Lagerstedt, according to Cleve.
+
+Willistown, Pa.
+
+Pl. 27, Fig. 24.
+
+
+NAVICULA PINNATA PANT. ?
+
+Valve lanceolate, obtuse; axial area narrow, widened in the middle; striæ
+coarse, 7 in 10 µ in the middle, radiate, 10 in 10 µ at the ends and
+transverse, indistinctly lineate. L. 40 µ.
+
+Near _Navicula ardua_ Mann (Diat. Albatross Voy., Cont. U. S. Nat.
+Herbarium Vol. 10, Part 5, p. 336, Pl. 53, Fig. 2) which, however, is said
+to have "strictly unbeaded costæ."
+
+Pavonia, N. J., artesian well.
+
+Pl. 27, Fig. 20.
+
+
+NAVICULA PENNATA A. S.
+
+Valve lanceolate, acute; axial area narrow; central area quadrate,
+transverse; striæ radiate, coarse, 5 in 10 µ, lineate. L. 68-95 µ (Cleve).
+
+Pavonia, N. J., artesian well.
+
+Pl. 27, Fig. 22.
+
+
+NAVICULA INFLEXA GREG.
+
+Valve slightly elliptical-lanceolate, sub-acute, smooth at the ends; axial
+area narrow, widened in the middle; striæ radiate, 11 in 10 µ, lineate.
+Frustule in zone view constricted in the middle. L. 28-45 µ.
+
+Common along the coast.
+
+Pl. 27, Figs. 18 and 19.
+
+
+{97}NAVICULA OBLONGA KUETZ.
+
+Valve linear-lanceolate, with broad, rounded ends; margin sometimes
+undulate; axial area narrow; central area large, orbicular; striæ in the
+middle distant, radiate, convergent at the ends and curved or sharply bent,
+7 in 10 µ, lineate. L. 70-200 µ (Cleve).
+
+Blue clay. Occasional in fresh water.
+
+Pl. 27, Fig. 21.
+
+
+NAVICULA HASTA PANT.
+
+Valve lanceolate, gently tapering to the obtuse, produced ends; axial area
+lanceolate, widened to an orbicular space in the middle; striæ radiate, the
+median coarse and quite distant, 5 in 10 µ, becoming closer at the ends
+where they are 12 in 10 µ, lineate. The distance between the median striæ
+gives the appearance of a stauros.
+
+Occasional in the blue clay.
+
+Pl. 27, Fig. 13.
+
+
+NAVICULA HASTA VAR. PUNCTATA N. VAR.
+
+Valve as in type but with striæ in the middle distinctly punctate and
+reaching the median line.
+
+Greenwich Point, Philadelphia.
+
+Pl. 27, Fig. 14.
+
+
+NAVICULA RHYNCOCEPHALA KUETZ.
+
+Valve lanceolate, with produced ends; axial area indistinct; central area
+small, rounded; striæ radiate in the middle, convergent at the ends, 10-11
+in 10 µ, punctate. L. 42 µ.
+
+Fresh water. Common.
+
+Pl. 31, Fig. 8.
+
+
+NAVICULA CRYPTOCEPHALA KUETZ.
+
+Valve lanceolate, with rostrate ends; axial area indistinct; central area
+small; striæ, 16 in 10 µ, lineate, radiate in the middle, convergent at the
+ends. L. 28 µ.
+
+Common in fresh water.
+
+Intermediate forms occur between N. rhyncocephala and N. cryptocephala.
+
+Pl. 31, Fig. 9.
+
+
+NAVICULA LONGA (GREG.) RALFS
+
+Valve slender, rhombic, elongated, with acute ends; axial area indistinct;
+central area small; striæ, 6 or 7 in 10 µ, radiate in the middle, elsewhere
+transverse; central pores closely approximate. L. 120 µ.
+
+New Rochelle, N. Y.
+
+Pl. 31, Fig. 10.
+
+Cleve refers this form to N. directa var. remota Grun. Some specimens are
+found in this locality showing the "generally twisted" median line
+mentioned by Gregory.
+
+
+MESOLEIÆ CL.
+
+Valve linear or elliptical; axial area narrow; central area quadrate; striæ
+radiate, finely punctate.
+
+
+NAVICULA MUTICA KUETZ.
+
+Valve ovate, elliptical or lanceolate; axial area narrow; central area
+dilated into a stauros not reaching the margin; striæ about 20 in 10 µ,
+more distant in the middle, radiate, punctate. A punctum occurs on one side
+of the central nodule.
+
+{98}Reported from New Jersey in fresh water. I have not found it. The
+figure is from a specimen from another locality.
+
+Pl. 26, Fig. 6.
+
+
+NAVICULA MINIMA GRUN.
+
+Valve broadly elliptical, 13-15 µ in length; axial area narrow; central
+area small but with a quadrate pseudo-stauros which is striated; striæ,
+about 28 in 10 µ, radiate.
+
+Agrees closely with N. saugeri var. Grun. in V. H. Synopsis, Pl. 14, Fig.
+16, said to be intermediate between N. minima and N. atomoides Grun. N.
+minima var. atomoides Grun. is smaller.
+
+Common in water-troughs.
+
+Pl. 26, Fig. 13.
+
+
+NAVICULA PUPULA VAR. BACILLARIOIDES GRUN.
+
+Valve linear, with rounded ends; axial area linear, expanding on both sides
+near the ends of the valve, forming a transverse lunate space; central area
+small, apparently expanded into a stauros, which, however, is striated;
+striæ, 18 in 10 µ, at the middle, closer at the ends, punctate. L. 54 µ.
+
+Pavonia, N. J., artesian well.
+
+Pl. 26, Fig. 9.
+
+
+BACILLARES CL.
+
+Valve linear or linear-elliptical, with broad ends; axial area narrow, the
+median line enclosed in siliceous ribs; striæ finely punctate, more distant
+in the middle.
+
+
+NAVICULA BACILLUM EHR.
+
+Valve linear, with rounded ends; axial area enclosed in siliceous ribs and
+slightly expanded on each side at the ends; terminal nodules incrassate;
+central area small, elliptical; striæ, 15 in 10 µ in the middle,
+transverse, distinctly punctate, closer at the ends L. 47 µ.
+
+Fresh water.
+
+Pl. 26, Fig. 10.
+
+Cleve describes the form as having slightly radiate striæ in the middle.
+There is considerable difference in the descriptions of Cleve, Donkin,
+Grunow and Van Heurck, as also in all of the figures.
+
+
+NAVICULA AMERICANA EHR.
+
+Valve oblong-linear, with rounded ends, sometimes slightly constricted;
+axial area about one-half the width of the valve, dilated in the middle;
+striæ parallel in the middle, radiate at the ends, 15-16 in 10 µ. A punctum
+is usually found in the central nodule. L. 55-154 µ.
+
+Blue clay. Occasional in fresh water.
+
+Pl. 26, Fig. 8.
+
+
+DECIPIENTES CL.
+
+Valve lanceolate, with obtuse ends; axial area narrow; central area
+orbicular; striæ radiate in the middle and more distant.
+
+
+NAVICULA SEMEN EHR.
+
+Valve elliptic-lanceolate, with sub-rostrate, truncate apices; axial area
+narrow, {99}sinuous; central area orbicular; terminal fissures small,
+hook-shaped; striæ robust, 7 or 8 in the middle, closer at the ends,
+indistinctly punctate or lineolate.
+
+Blue clay. Not common.
+
+Pl. 26, Fig. 11.
+
+Cleve states that this form belongs to the post-glacial deposits and is
+found living only in the Hartz Mountains.
+
+
+NAVICULA INTEGRA WM. SM.
+
+Valve lanceolate with triundulate margins and rostrate-apiculate ends;
+striæ radiate, more distant in the middle, 20-23 in µ, punctate; axial area
+very narrow, central area rounded or elliptical. L. 33-43 µ.
+
+Pavonia, N. J., artesian well. Common in Chester River, Md.
+
+Pl. 26, Fig. 5.
+
+
+MICROSTIGMATICÆ CL.
+
+Valve lanceolate; axial area narrow; central area small, rounded; striæ
+finely punctate, nearly parallel. (Includes here only the division
+Libellus.)
+
+
+NAVICULA TUMIDA (BRÉB.) CL.
+
+Valve lanceolate, with rounded ends; axial area narrow, central area
+elliptical; raphe slightly sigmoid; striæ, 13 in 10 µ, finely punctate, a
+few shorter in the middle.
+
+_Scoliopleura tumida_ (Bréb.) V. H.
+
+Cape May, N. J.
+
+Pl. 25, Fig. 1.
+
+
+NAVICULA GREVILLEI (AG.) CL.
+
+Frustules in gelatinous tubes, rectangular; zone with numerous longitudinal
+divisions. Valve elliptical-lanceolate, obtuse; axial area narrow, central
+area small; striæ lineate, about 18 in 10 µ in the middle where they are
+slightly radiate and more evident, closer near the ends and transverse;
+median line with terminal pores distant from the ends. L. 60 µ.
+
+_Schizonema grevillei_ Ag.
+
+East River, N. Y.
+
+Pl. 31, Figs. 3 and 4.
+
+
+NAVICULA LIBELLUS GREG.
+
+Valve rhombic-elliptical, obtuse at the ends; axial area narrow, central
+rounded, small; striæ punctate, slightly radiate, about 19 in 10 µ;
+terminal fissures close to the ends, indistinct. L. 60 µ.
+
+Cleve describes this form as having acute ends, while Gregory states that
+it is "more obtuse and broader than N. rhombica." Gregory's Figure 101
+apparently shows the ends acute, but he says that the valve view is
+"rhombic or elliptic-lanceolate, broad, with obtuse ends" (Diat. of the
+Clyde, p. 57, Pl. 6).
+
+Hackensack Swamp, N. J.
+
+Pl. 31, Fig. 5.
+
+
+ORTHOSTICHÆ CL.
+
+Valve lanceolate or elongated; axial area narrow; central area sometimes
+apparently dilated into a stauros; striæ punctate, the puncta in transverse
+and longitudinal rows.
+
+
+{100}NAVICULA CUSPIDATA KUETZ.
+
+Valve rhombic-lanceolate, with acute ends; axial area linear, narrow, not
+widened in the middle; striæ transverse, 14-19 in 10 µ (Cl.). L. 70-150 µ.
+
+Blue clay. Not uncommon in fresh water.
+
+Pl. 26, Figs. 1 and 2.
+
+Fig. 2 represents an inner valve or stratum, with strong costæ variable in
+size, formerly known as Surirella craticula Ehr.
+
+_N. cuspidata var. ambigua (Ehr.) Cl._--Valve elliptical-lanceolate, with
+rostrate ends, smaller than the type and with finer striæ.
+
+Crum Creek.
+
+Pl. 26, Fig. 3.
+
+
+NAVICULA SPICULA (HICKIE) CL.
+
+Valve narrow, lanceolate with acute ends; axial area narrow, central area
+dilated into a stauros reaching the margin; transverse striæ, 25-29 in 10
+µ, longitudinal closer. L. 50-130 (Cl.).
+
+Sometimes confused with N. crucigera.
+
+_Stauroneis spicula_ Hickie.
+
+Newark, N. J.
+
+Pl. 26, Fig. 4.
+
+
+NAVICULA CRUCIGERA (WM. SM.) CL.
+
+Valve lanceolate, narrow, with acute apices; central nodule a stauros
+reaching the margin but crossed by two or three coarser striæ; transverse
+striæ, 12 in 10 µ, punctate, the puncta about 25 in 10 µ. L. 80-100 µ
+(Cl.). Frustules in gelatinous tubes or free.
+
+_Schizonema cruciger_ Wm. Sm.
+
+Pl. 26, Fig. 15.
+
+Reported as occurring in New York Bay, but I have not seen it. The figure
+is from a specimen from another locality.
+
+
+MINUSCULÆ CL.
+
+Valve lanceolate or elliptical, chiefly distinguished by the small size;
+axial area indistinct; central area small; striæ radiate, very finely
+punctate.
+
+
+NAVICULA ATOMUS NÆGELI
+
+Valve elliptical, 6-8 µ in length; striæ radiate, 26-30 µ, closer near the
+ends; axial area linear, scarcely widened in the middle.
+
+Water-troughs and ditches. Probably common, but frequently not noticed
+because of its minuteness. A mounting medium of the highest refractive
+index, such as realgar, is required to resolve the striæ. In the figure the
+striæ are drawn a little coarser than they appear in most specimens.
+
+Pl. 26, Fig. 12.
+
+
+LÆVISTRIATÆ CL.
+
+Valve lanceolate, axial area distinct; central area orbicular; striæ
+coarse, indistinctly punctate, approaching the costæ of Pinnularia.
+
+
+{101}NAVICULA YARRENSIS GRUN.
+
+Valve elliptical-lanceolate, with rounded ends; axial area lanceolate,
+widened in the middle; striæ, 5 in 10 µ. L. 97 µ.
+
+Cape May, N. J. Common.
+
+Pl. 25, Fig. 14.
+
+Fig. 15, a smaller form, 65 µ in length; striæ, 6 in 10 µ.
+
+Fig. 16, 54 µ in length; striæ, 8 in 10 µ (near var. valida Pant.).
+
+
+NAVICULA ELEGANS WM. SM.
+
+Valve elliptical-lanceolate, with produced ends; axial area very narrow,
+central area large, orbicular; striæ strongly divergent in the middle,
+slightly, if at all, convergent at the ends, curved toward the margin,
+indistinctly lineate, 9 in 10 µ. L. 95 µ.
+
+Blue clay. Not rare.
+
+Pl. 31, Fig. 1.
+
+_Navicula elegans var. cuspidata Cl._--Valve as in type form but smaller
+and with rostrate apices; striæ, 10 in 10 µ. L. 82 µ.
+
+Belmar, N. J.
+
+Pl. 31, Fig. 2.
+
+Cleve remarks that the type form is acute and the striæ 9, while the var.
+cuspidata has 12 striæ in 10 µ. In Fig. 1, Pl. 31, is represented a valve
+having 9 striæ in 10 µ, but not acute, while Fig. 2, with but slight
+variation in striæ, is more cuspidate. It is probable there are
+intermediate variations.
+
+
+NAVICULA PALPEBRALIS BRÉB.
+
+Valve elliptical-lanceolate, with acute apiculate ends; axial area broad,
+lanceolate; striæ radiate, lineate, about 11 in 10 µ. L. 60 µ.
+
+Along the coast.
+
+Pl. 31, Figs. 6 and 7.
+
+On Plate 40, Fig. 5, is represented an abnormal form of Navicula in which
+the central pores are in a line transverse to the longitudinal axis and
+each raphe is curved in a line which almost returns to the centre. The
+puncta are in curved lines radiating from the rounded hyaline centre.
+
+Pavonia, N. J., artesian well.
+
+Weissflog has described valves of Navicula somewhat similar in punctation.
+
+
+PINNULARIA EHR. (1843)
+
+(pinnula, a small feather)
+
+Valve linear or nearly so, with rounded ends; axial area broad; central and
+terminal areas large; costæ smooth, transverse or radiating, usually
+convergent at the ends.
+
+The costæ are channels on the inside of the valve, closed, except in the
+middle where elliptical foramina, opening into the interior of the valve,
+give rise through their terminal margins to the two longitudinal lines on
+each side of the valve. The raphe begins as a groove in the side of the
+conical central nodule and continues as a cleft at right angles to the
+plane of the surface of the valve, in which case the raphe forms a single
+line; if the raphe is inclined to the valve surface, then two lines appear
+in projection, the upper and lower edges of the cleft. In some forms the
+surface of the edge of the raphe on one side is folded or grooved for a
+considerable distance, and the opposite edge is elevated into a ridge or
+{102}tongue fitting into the groove. In such cases it is possible, in
+projection, to see the upper or outer edges of the raphe, the lower edges
+and the edges of the tongue and groove, thus showing four lines; sometimes,
+when the tongue and groove do not meet, six lines. The so-called inner
+channel is the part of the raphe on the inside of the tongue, and the
+so-called exterior channel is the part of the raphe on the outside of the
+tongue. If, in addition to this formation of the raphe, the plane of
+cleavage changes toward the terminal nodules, the lines will cross each
+other and, when two are superimposed, disappear altogether. For the careful
+examination of the raphe it is necessary to employ large forms, and it is
+advisable to use nitrate of silver which remains in the raphe, and, as in
+slides mounted by Mr. F. J. Keeley, shows in a beautiful manner the entire
+outline of raphe and fissures. The terminal fissures owe their separation
+to the different directions taken by the two edges of the raphe on each
+side, one edge bending in a wide curve toward the end of the valve, showing
+two lines, the upper and lower edges of one side of the raphe when inclined
+to the plane of the surface, and the other edge of the raphe turning
+suddenly in an opposite direction and ending abruptly in a curve, giving
+rise to the appearance, by diffraction, of a punctum.
+
+Pl. 40, Figs. 13, 14 and 15.
+
+Endochrome consists of two chromatophores lying on the zones.
+
+Pinnularia is usually divided into the Majores, or larger, and the Minores,
+or smaller forms, the latter being further divided according to their
+striæ. The following classification is chiefly that of Cleve.
+
+_Majores._--Valve large, linear with parallel or slightly radiate striæ and
+broad axial area.
+
+_Gracillimæ._--Valve small, striæ parallel or nearly so; axial area very
+narrow.
+
+_Capitatæ._--Valve with capitate or rostrate ends; striæ radiate.
+
+_Divergentes._--Striæ strongly radiate.
+
+_Brevistriatæ._--Striæ short.
+
+_Distantes._--Striæ distant.
+
+_Tabellariæ._--Striæ radiate in the middle, strongly convergent at the
+ends.
+
+_Marinæ._--Marine forms.
+
+
+MAJORES
+
+PINNULARIA MAJOR (KUETZ.) WM. SM.
+
+Valve linear, usually slightly gibbous in the middle and at the ends; raphe
+oblique; axial area less than one-third the width of valve, convergent at
+the ends; striæ, 7 or 8 in 10 µ, radiate in the middle, convergent at the
+ends, crossed by a narrow band. L. ? to 300 µ.
+
+Blue clay. Fresh water. Abundant at Middletown, Delaware Co. (T. C.
+Palmer).
+
+Pl. 28, Fig. 4.
+
+Fig. 9, Pl. 29, is one of a number of smaller forms which are difficult to
+determine, approaching P. viridis.
+
+
+PINNULARIA MAJOR VAR. PULCHELLA N. VAR.
+
+Valve strongly gibbous in the middle and gradually widened to the rounded
+ends; axial area broad, less than one-third the width of the valve, widened
+unilaterally in the middle; striæ, 7 in 10 µ, crossed by a band nearly as
+wide as the length of the costæ and scarcely distinct. L. 273 µ.
+
+{103}The central nodule is scarcely evident, probably because it is not so
+thick as in other forms. The outline is near to that of N. mesogongyla and
+certain forms of N. nobilis, differing from the latter in the median line,
+striæ and band which is wider than that of P. latevittata var. domingensis
+Cl.
+
+Hammonton Pond, N. J.
+
+Pl. 28, Fig. 2.
+
+A very beautiful form which I cannot find described or figured. It does not
+appear to be N. major var. turgidula Cl., which has a narrow band. In the
+fossil deposit from Hopkinton, N. H., valves occur similar in outline but
+smaller.
+
+
+PINNULARIA NOBILIS EHR.
+
+Valve slightly gibbous in the middle and at the ends; median line complex;
+striæ, 4 or 5 in 10 µ, slightly convergent or parallel at the ends, crossed
+by a band one-third as wide as the length of the striæ. L. ? to 350 µ.
+
+Blue clay. Fresh water.
+
+Pl. 28, Fig. 1.
+
+
+PINNULARIA DACTYLUS EHR.
+
+Valve broad, linear, slightly gibbous in the middle; ends broad, rounded;
+median line not complex, sinuous; striæ, 4 or 5 in 10 µ, crossed by a very
+broad band. L. ? to 300 µ.
+
+_Navicula gigas_ A. S.
+
+Blue clay. Fresh water.
+
+Pl. 28, Fig. 3.
+
+Forms occur which are with difficulty assigned to either nobilis or
+dactylus.
+
+
+PINNULARIA DACTYLUS VAR. DARIANA (A. S.) CL.
+
+Valve linear-lanceolate, obtuse; axial area broad, less than one-third the
+width of the valve; striæ, 6 in 10 µ, crossed by a broad band. L. 220 µ.
+
+Absecon, N. J.
+
+Pl. 29, Fig. 3.
+
+
+PINNULARIA DACTYLUS VAR. DEMERARÆ CL.
+
+Valve elliptical-lanceolate, with sub-cuneate ends; axial area lanceolate,
+broad in the middle; median line flexuose; striæ radiate throughout, 6 in
+10 µ. L. 150 µ.
+
+Blue clay.
+
+Pl. 29, Fig. 10.
+
+
+PINNULARIA GENTILIS (DONK.) CL.
+
+Valve linear, with rounded ends; axial area about one-fourth the diameter
+of the valve; striæ radiate in the middle, convergent at the ends, 7 in 10
+µ, crossed by a broad indistinct band.
+
+Fresh water. Not common.
+
+Pl. 29, Fig. 1.
+
+
+PINNULARIA TRIGONOCEPHALA CL.
+
+Valve linear, gibbous in the middle and at the cuneate ends; axial area
+wider between the middle and the ends, dilated to an elliptical space in
+the middle; striæ, 6 in 10 µ. L. 145 µ.
+
+Blue clay.
+
+Pl. 29, Fig. 8.
+
+
+{104}PINNULARIA VIRIDIS NITZSCH
+
+Valve linear-elliptical, with rounded ends; axial area narrow, widened in
+the middle; striæ, 6 to 7 in 10 µ, crossed by a band as wide as one-third
+the length of the striæ.
+
+Common in fresh water.
+
+Pl. 29, Fig. 2.
+
+Quite variable in size. Approaches P. major by intermediate forms as in
+Fig. 9, Pl. 29.
+
+
+PINNULARIA VIRIDIS VAR. FALLAX CL.
+
+Valve linear, with rounded ends; axial area narrow, slightly widened in the
+middle; striæ sometimes unilaterally interrupted, nearly parallel, 10 in 10
+µ.
+
+Elm, N. J.
+
+Pl. 29, Fig. 4.
+
+In Fig. 2, Pl. 30, a form is represented which corresponds closely to
+Navicula viridis var. B, of Wm. Smith. It is given as synonymous with var.
+fallax; it is bilaterally interrupted. Blue clay.
+
+
+PINNULARIA VIRIDIS VAR. ?
+
+Valve linear-elliptical, with rounded ends; axial area narrow, widened in
+the middle to a transverse fascia which is sometimes unilateral; striæ, 14,
+in the middle, divergent, convergent at the ends and closer, crossed by a
+narrow band. L. 45-60 µ. Fascia sometimes absent or very narrow.
+
+Northbrook, Pa.
+
+Pl. 30, Fig. 17 (represents a form with wider area than usual).
+
+
+PINNULARIA VIRIDIS VAR. CAUDATA N. VAR.
+
+Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow,
+widened to an orbicular space in the middle; striæ radiate in the middle,
+11-12 in 10 µ, convergent and closer at the ends, crossed by a narrow band;
+median line with very long terminal fissures; terminal nodules noticeable
+because of the thickening of the edges of the terminal striæ. L. 43 µ.
+
+Fresh water, Newtown Square. Not common.
+
+Pl. 30, Fig. 18.
+
+
+PINNULARIA SOCIALIS (PALMER)
+
+Valve linear, with rounded ends; axial area broad, one-third the width of
+the valve; striæ slightly radiate in the middle, convergent at the ends,
+elsewhere parallel, 8 in 10 µ, crossed by an indistinct band about
+one-third the length of the striæ. L. 60-120 µ.
+
+This species, discovered by Mr. Palmer near Media, Pa., is remarkable for
+the grouping of the frustules "held with girdle sides together by a
+siliceous cementing of valve edges and enclosed in a common coleoderm." The
+usual number included in a group is four, but sometimes six or eight are
+noticed. The frustules adhere near their ends and are so firmly fastened
+that boiling in nitric acid and bichromate of potash for fifteen minutes
+will not separate them.
+
+_Navicula socialis_ Palmer (Proc. Acad. Nat. Sci., Phila., 1910, p. 460,
+Pl. 35).
+
+Media, Pa.
+
+Pl. 29, Fig. 5.
+
+
+{105}PINNULARIA ÆSTUARII CL.
+
+Valve linear, with rounded ends; axial area broad, less than one-third the
+width of the valve; central area a transverse fascia; striæ, 7 in 10 µ,
+parallel except at the ends where they are slightly convergent; median line
+flexuose, with short, terminal semicircular fissures. L. 85 µ.
+
+Port Penn, Delaware River. Rare.
+
+Pl. 29, Fig. 6.
+
+
+GRACILLIMÆ
+
+PINNULARIA MOLARIS (GRUN.) CL.
+
+Valve very convex, linear, with sub-cuneate ends; axial area narrow,
+expanded in the middle to a transverse fascia reaching the margin; striæ
+divergent in the middle, convergent at the ends, 16 in 10 µ. L. 60 µ.
+
+Fresh water.
+
+Pl. 29, Fig. 15.
+
+
+PINNULARIA LEPTOSOMA GRUN.
+
+Valve linear, rounded at the ends; axial area narrow; central area a broad
+transverse fascia; striæ slightly divergent in the middle and convergent at
+the ends, 17 in 10 µ in the middle, closer at the ends. L. 56 µ.
+
+Fresh water. Not common.
+
+Pl. 30, Fig. 10.
+
+
+CAPITATÆ
+
+PINNULARIA MESOLEPTA EHR.
+
+Valve linear, with triundulate margins and capitate ends; axial area
+narrow, widened in the middle; striæ divergent in the middle, convergent at
+the ends, about 12 in 10 µ. L. 34 µ.
+
+Common in fresh water.
+
+Pl. 29, Fig. 13.
+
+
+PINNULARIA MESOLEPTA VAR. STAURONEIFORMIS GRUN.
+
+Valve triundulate, capitate; axial area narrow, widened in the middle to a
+transverse fascia, broader at the margin; striæ strongly divergent in the
+middle and convergent at the ends, 9-10 in 10 µ. L. 70 µ.
+
+Pavonia, N. J., artesian well. Fresh water.
+
+Pl. 30, Fig. 20.
+
+
+PINNULARIA SUBCAPITATA GREG.
+
+Valve linear or linear-elliptical, with sub-capitate ends; axial area
+distinct, widened to a transverse fascia in the middle; striæ divergent in
+the middle, convergent at the ends, 13 in 10 µ. L. 32 µ.
+
+Fresh water.
+
+Pl. 29, Fig. 20.
+
+
+{106}PINNULARIA SUBCAPITATA VAR. PAUCISTRIATA GRUN.
+
+Valve linear-elliptical, with rounded ends; axial area gradually widened
+into a broad, transverse fascia; striæ divergent in the middle, convergent
+at the ends, 11-12 in 10 µ. L. 47 µ.
+
+Fresh water.
+
+Pl. 30, Fig. 16.
+
+
+PINNULARIA TERMES (EHR.) A. S.
+
+Valve linear, with concave margins and rostrate-capitate ends; axial area
+narrow, widened in the middle to an orbicular or sub-quadrate space; striæ
+divergent in the middle, scarcely, if at all, convergent at the ends, 10 in
+10 µ.
+
+Pensauken, N. J., artesian well.
+
+Pl. 29, Fig. 17.
+
+This is, I believe, the form figured by Schmidt (Atlas, Pl. 45, Fig. 67).
+Cleve refers it to Pinnularia interrupta forma biceps, in which the central
+space is rhomboid.
+
+
+PINNULARIA TERMES VAR. STAURONEIFORMIS V. H.
+
+Valve linear, with concave margins and capitate-rostrate ends; axial area
+narrow, widened into a rhomboidal fascia, reaching the margin; striæ, 10 in
+10 µ, divergent in the middle, convergent at the ends.
+
+_Pinnularia interrupta forma stauroneiformis_ Cl.
+
+Fresh water.
+
+Pl. 29, Fig. 14.
+
+
+PINNULARIA APPENDICULATA (AG.) CL.
+
+Valve linear, with subcapitate ends; axial area narrow; central area a
+transverse fascia; striæ divergent in the middle, convergent at the ends,
+16 in 10 µ. L. 43 µ.
+
+Fresh water. Marl pits, Lenola, N. J. (Palmer).
+
+Pl. 29, Fig. 18.
+
+
+PINNULARIA BRAUNII GRUN.
+
+Valve linear-lanceolate, with capitate ends; axial area gradually widened
+toward the middle and expanded into a fascia reaching the margin; striæ
+divergent in the middle, convergent at the ends, 11 in 10 µ. L. 52 µ.
+
+Pensauken, N. J., artesian well.
+
+Pl. 29, Fig. 16.
+
+
+PINNULARIA MICROSTAURON (EHR.) CL.
+
+Valve convex, linear, tapering to sub-cuneate or sub-rostrate ends; axial
+area very narrow; central area a broad fascia; striæ divergent in the
+middle, convergent at the ends, 12 in 10 µ. L. 35 µ.
+
+Pavonia, N. J., artesian well.
+
+Pl. 29, Fig. 19.
+
+This form does not exactly correspond to Cleve's diagnosis, as the ends are
+not broad. All species in the group Capitatæ are quite variable.
+
+
+{107}DIVERGENTES
+
+PINNULARIA DIVERGENS VAR. ELLIPTICA GRUN.
+
+Valve linear, with rounded ends; axial area widened in the middle to a
+transverse fascia; striæ, 9 in 10 µ, divergent in the middle, convergent at
+the ends. L. 150 µ.
+
+Fresh water. Not common in this locality.
+
+Pl. 31, Fig. 13.
+
+
+PINNULARIA CARDINALICULUS CL.
+
+Valve linear, with rounded ends; axial area wide, less than one-third the
+width of the valve, expanded to a transverse fascia; striæ divergent in the
+middle and slightly convergent at the ends, 9 in 10 µ. L. 97 µ.
+
+Blue clay.
+
+Pl. 30, Fig. 1.
+
+As a rule, the median fissures in Pinnularia are turned inwards on the side
+of the longer edge of the terminal fissures, but not always. In this
+specimen the median fissures are turned slightly toward the side of the
+shorter edge of the terminal fissures.
+
+
+PINNULARIA LEGUMEN EHR.
+
+Valve linear, with more or less triundulate margins and broad, capitate
+ends; axial area less than one-fourth the width of valve, widened in the
+middle; striæ strongly divergent in the middle and convergent at the ends,
+10 in 10 µ. L. 84 µ.
+
+Fresh water. May's Landing, N. J.
+
+Pl. 30, Fig. 3.
+
+
+PINNULARIA LEGUMEN VAR. ?
+
+Valve as in type, but with a transverse fascia; striæ, 10 in 10 µ, curved
+or bent near the ends. L. 84 µ.
+
+This form is not var. florentina Grun.
+
+May's Landing, N. J. (with the type).
+
+Pl. 30, Fig. 4.
+
+
+PINNULARIA BRÉBISSONII (KUETZ.) CL.
+
+Valve linear-elliptical, with rounded ends; axial area narrow, widened into
+a transverse fascia which is usually broader at the ends; striæ divergent
+in the middle, convergent at the ends, about 12 in 10 µ. L. 40-60 µ (Cl.).
+
+Fresh water. Common.
+
+Pl. 29, Fig. 12; Pl. 31, Fig. 11.
+
+Variable in outline.
+
+
+PINNULARIA MORMONORUM (GRUN.)
+
+Valve linear, with rounded ends; striæ divergent in the middle, convergent
+at the ends, 10 in 10 µ; axial area rhombic-lanceolate, widened to a fascia
+usually reaching the border. L. 62 µ.
+
+_Navicula mormonorum_ Grun.
+
+Common near Willistown, Pa.
+
+This form is regarded by Cleve as P. brébissonii, but the axial area
+appears to distinguish it. The valves are sometimes narrowed in the middle.
+
+Pl. 29, Fig. 11.
+
+
+{108}BREVISTRIATÆ
+
+PINNULARIA ACROSPHÆRIA (BRÉB.) CL.
+
+Valve linear, gibbous in the middle and at the ends; axial area about half
+the width of the valve; median line with approximate central pores; median
+area punctate; striæ nearly parallel, radiate at the ends, 9 in 10 µ. L.
+32-180 µ (Cl.).
+
+Blue clay. Recent, fresh water.
+
+Pl. 30, Fig. 7.
+
+
+PINNULARIA ACROSPHÆRIA VAR. TURGIDULA GRUN. ?
+
+Valve strongly gibbous in the middle; ends rounded; striæ, 12-13 in 10 µ.
+L. 54 µ.
+
+Blue clay, Gloucester, N. J., artesian well.
+
+Pl. 30, Fig. 8.
+
+
+PINNULARIA BLANDITA N. SP.
+
+Valve linear, gibbous in the middle, and with rounded ends; striæ radiate
+in the middle, convergent at the ends, 13 in 10 µ; axial area about
+one-fourth the width of the valve, widened in the middle; median line with
+small semicircular terminal fissures. L. 65 µ.
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 30, Fig. 25.
+
+
+PINNULARIA PARVA (EHR.) CL. VAR. ?
+
+Valve linear, tapering to the subcapitate ends; axial area broad,
+lanceolate; median line with approximate central pores and semicircular
+terminal fissures; striæ slightly divergent in the middle and convergent at
+the ends, 12 in 10 µ. L. 58 µ.
+
+Differs from the type in having finer striæ.
+
+Atco, N. J.
+
+Pl. 30, Fig. 14.
+
+
+PINNULARIA NODOSA FORMA CAPITATA CL.
+
+Valve triundulate, with capitate ends; axial area about one-fourth the
+width of valve; striæ parallel, convergent at the ends, 10 in 10 µ,
+sometimes interrupted in the middle. L. 47 µ.
+
+Fresh water. Common.
+
+Pl. 30, Figs. 15 and 19.
+
+
+PINNULARIA POLYONCA (BRÉB.) LEWIS
+
+Valve with triundulate margins, more inflated in the middle, with capitate
+ends; axial area very broad; striæ marginal, short, 9 in 10 µ, divergent in
+the middle, convergent at the ends. L. 97 µ.
+
+Kirkwood Pond, N. J.
+
+Pl. 30, Fig. 21.
+
+The description of Kuetzing (Species Algarum, p. 85), where he states that
+the margins are "triundulate, the median inflation larger, apices
+rounded-capitate," appears to sufficiently distinguish this species, which
+I believe to be the same as Brun's Navicula peripunctata, except that the
+form figured (Espèces Nouvelles, Pl. 16, Fig. 11) is interrupted in the
+middle, a common variation in these forms. Cleve makes Navicula polyonca
+Bréb. equal Pinnularia mesolepta, but at the same time he considers Lewis'
+form and also Brun's as equivalent to Navicula formica Ehr., and calls it
+Pinnularia nodosa var. formica Ehr. P. mesolepta has a narrower area than
+nodosa. I adhere to Lewis' identification, as in any case it is the form
+here figured and is nearly, if not quite, the same as Brun's species.
+
+
+{109}DISTANTES
+
+PINNULARIA LATA (BRÉB.) WM. SM.
+
+Valve linear-elliptical, broad; axial area broad, widened in the middle;
+striæ slightly radiate in the middle, 3 in 10 µ; median line oblique, the
+terminal fissures hook-shaped. L. 86 µ.
+
+Blue clay. Not uncommon.
+
+Pl. 30, Fig. 23.
+
+
+PINNULARIA BOREALIS EHR.
+
+Valve linear, with rounded or sub-truncate ends; axial area about
+one-fourth the width of the valve, widened in the middle; median line with
+large hook-shaped terminal fissures; striæ, 4 or 5 in 10 µ. L. 54 µ.
+
+Blue clay. Occasional in fresh water in a smaller form. Specimens occur
+intermediate between P. lata and P. borealis.
+
+Pl. 30, Fig. 22; Pl. 31, Fig. 12.
+
+
+PINNULARIA BOREALIS VAR. SCALARIS (EHR.) CL.
+
+Valve narrow, linear; axial area broad, widened into a transverse fascia;
+striæ, 8 in 10 µ. L. 32 µ.
+
+Fresh water.
+
+Pl. 30, Fig. 24.
+
+
+TABELLARIÆ
+
+PINNULARIA STOMATOPHORA (GRUN.) CL.
+
+Valve linear, with rounded ends; axial area less than one-third the width
+of the valve, gradually widened in the middle to a transverse fascia; on
+each side of the central nodule is a lunate space; striæ divergent in the
+middle, convergent at the ends, 13 in 10 µ; terminal fissures very long,
+bayonet shaped. L. 75 µ.
+
+Cleve describes a variety continua as not interrupted. In some forms the
+fascia is marked by very faint, short striæ on the margin.
+
+Fresh water. Newtown Square.
+
+Pl. 30, Fig. 12.
+
+
+PINNULARIA GIBBA (KUETZ.) V. H.
+
+Valve linear, tapering to the subcapitate ends; axial area dilated in the
+middle; striæ, 10-11 µ, divergent in the middle, convergent at the ends. L.
+80 µ.
+
+Fresh water.
+
+Pl. 30, Fig. 5.
+
+
+PINNULARIA MESOGONGYLA (EHR.) CL.
+
+Valve linear, gibbous in the middle, ends subcapitate; axial area narrow,
+widened in the middle to a large orbicular space; striæ strongly divergent
+in the middle, convergent at the ends, 11 in 10 µ. L. 60 µ.
+
+Fresh water. Common.
+
+Pl. 30, Fig. 6.
+
+
+{110}PINNULARIA STAUROPTERA (GRUN.) CL.
+
+Valve linear, with slightly triundulate margins tapering to the subcapitate
+ends; axial area more than one-third the width of the valve, slightly
+widened in the middle; median line with approximate central pores and
+semicircular terminal fissures; striæ divergent in the middle, convergent
+at the ends, 11 in 10 µ. L. 82 µ.
+
+May's Landing, N. J.
+
+Pl. 30, Fig. 13.
+
+Some of the forms are more triundulate than the specimen figured.
+
+
+PINNULARIA STAUROPTERA VAR. INTERRUPTA CL.
+
+Valve linear, tapering to the subcapitate ends; axial area broad, widened
+in the middle to a transverse fascia; striæ divergent in the middle,
+convergent at the ends, 10 in 10 µ; median pores approximate. L. 118 µ.
+
+Schuylkill River.
+
+Pl. 30, Fig. 11.
+
+
+PINNULARIA TABELLARIA (EHR.) CL.
+
+Valve linear, gibbous in the middle and tapering to the subcapitate ends;
+axial area about one-third the width of the valve, widened in the middle;
+median line with approximate central pores and bayonet-shaped terminal
+fissures; striæ sometimes unilaterally interrupted, divergent in the
+middle, strongly convergent at the ends, 9 in 10 µ. L. 138 µ.
+
+Blue clay. Rare.
+
+Pl. 30, Fig. 9.
+
+The form here figured has coarser striæ than in the type which is also
+usually more capitate.
+
+P. legumen has triundulate margins, P. mesogongyla has an orbicular space,
+while P. gibba has the space widened. According to Cleve, P. gibba has
+approximate central pores, as has also P. mesogongyla. In what I have
+considered to be P. legumen, the central pores are more approximate than in
+the other two species mentioned. In fact, all of the three resemble each
+other closely, and are variously named by different authors. The form of P.
+gibba here figured, which may be P. stauroptera, is not the typical form of
+Wm. Smith, which has a narrow area and central space. There are, however,
+among the typical specimens in H. L. Smith's Type Slide No. 275, smaller
+valves which show a resemblance.
+
+
+MARINÆ
+
+PINNULARIA RECTANGULATA (GREG.) CL.
+
+Valve linear, with abruptly rounded ends; axial area very narrow; central
+area large, somewhat quadrate; striæ, 7-8 in 10 µ. L. 78 µ.
+
+_Navicula rectangulata Greg._
+
+Shark River, N. J.
+
+Pl. 29, Fig. 7.
+
+
+{111}EPITHEMIA BRÉB. (1838)
+
+(epithema, a cover or lid)
+
+Frustules epiphytic, solitary, sometimes geminate, adherent on the ventral
+side at the ends; in zone view rectangular, sometimes tumid in the middle.
+Valve arcuate, having an interior costate stratum or transverse septa
+extending to the girdle, often detached, and an exterior valve surface with
+transverse rows of puncta. Central and terminal nodules not easily seen; in
+some species a true raphe is indicated.
+
+The resemblance between Epithemia and Eunotia has been already mentioned.
+In the shape and striation of the valves there is an approach to Cymbella.
+
+The genus is divided into two groups, one in which the costæ alternate with
+double rows of puncta, as in E. turgida, and the other in which the rows of
+puncta are more than two.
+
+The endochrome usually consists of a band lying along the ventral zone and
+extending in two flaps on the valves.
+
+
+EPITHEMIA TURGIDA (EHR.) KUETZ.
+
+Valve arcuate, with ends subcapitate; costæ radiate, 4 in 10 µ, alternating
+with double rows of puncta. Median nodule central, the raphe curved toward
+the ventral edge which it closely follows.
+
+Parasitic on algæ. Very common in fresh water, especially in ponds. In the
+figure the valve is asymmetrical with respect to the transverse axis, an
+unusual condition.
+
+Pl. 31, Fig. 14.
+
+
+EPITHEMIA ARGUS KUETZ.
+
+Valve with dorsal margin convex, and ventral margin nearly straight; ends
+rounded, constricted; costæ robust, alternating with more than two rows of
+puncta; zone view rectangular, the thickened ends of the costæ forming
+large nodules in a row along the edge of the valve next to the connecting
+zone.
+
+_Cystopleura argus_ (Ehr.) Kunze.
+
+Common in fresh water.
+
+Pl. 31, Figs. 15 and 21.
+
+
+EPITHEMIA ARGUS VAR. ?
+
+Valve strongly arcuate on the dorsal side and concave on the ventral;
+tapering to the rounded but not produced ends; costæ at unequal distances,
+about 2 in 10 µ; granules in transverse rows, 8 in 10 µ. L. 100 µ.
+
+Pensauken, N. J., artesian well.
+
+Pl. 31, Fig. 16.
+
+
+EPITHEMIA MUELLERI A. S. ?
+
+Valve broad, convex, slightly arcuate, with obtuse, somewhat constricted
+apices; costæ about 4 in 10 µ; striæ, 12-14 in 10 µ; in zone view the
+outline is rectangular, slightly tumid in the middle. L. 78 µ.
+
+Blue clay.
+
+Pl. 31, Fig. 17.
+
+
+{112}EPITHEMIA ZEBRA VAR. PROBOSCIDEA (KUETZ.) GRUN.
+
+Valve convex on the dorsal, concave on the ventral side; costæ, 3-4 in 10
+µ, slightly radiating; apices recurved, capitate.
+
+Blue clay.
+
+Pl. 31, Fig. 18.
+
+
+EPITHEMIA GIBBERULA VAR. PRODUCTA GRUN.
+
+Valve narrow, lunate, with produced and arcuate apices; costæ radiate, 3-4
+in 10 µ; striæ, 16-18 in 10 µ, punctate. L. 58 µ, usually smaller.
+
+Blue clay.
+
+Pl. 31, Fig. 19.
+
+
+EPITHEMIA MUSCULUS KUETZ.
+
+Valve short, strongly arcuate on the dorsal, concave on the ventral side;
+apices slightly produced; costæ radiate, about 5 in 10 µ; striæ, 15 in 10
+µ, punctate. L. 20-60 µ.
+
+Shark River, N. J.
+
+Pl. 31, Fig. 20.
+
+
+EPITHEMIA MUSCULUS VAR. CONSTRICTA (BRÉB.) V. H.
+
+Frustule elliptical, slightly constricted in the middle. Valve convex on
+the dorsal, straight on the ventral side; costæ about 4 in 10 µ; striæ
+about 18 in 10 µ, finely punctate. L. 45 µ.
+
+_Epithemia succinta_ Bréb.
+
+New Rochelle, N. Y.
+
+Pl. 31, Fig. 22.
+
+
+RHOPALODIA MUELLER (1885)
+
+(Rhopalodes, like a war club)
+
+Frustule in zone view linear, linear-elliptical (in our species), or
+clavate. Valve reniform or lunate; a raphe, not visible in some species in
+the usual position of the valve, is found along the convex edge or keel.
+Median and terminal nodules, although very small, can be determined. The
+name is more appropriate to the African species which are clavate. Two
+species only are found in this locality.
+
+The chief distinction between Epithemia and Rhopalodia is in the position
+of the raphe and the nodules. In R. gibba and R. ventricosa the costæ are
+parallel and not radiate since the valves are not lunate.
+
+Chromatophore a single band irregularly divided.
+
+
+RHOPALODIA GIBBA (KUETZ.) MUELLER
+
+Valve linear, arcuate on the dorsal, straight on the ventral side, reflexed
+at the extremities. Costæ, 6-7 in 10 µ; striæ about 14 in 10 µ. L. 80-200
+µ.
+
+Fresh water. Common.
+
+Pl. 31, Fig. 23.
+
+In this species the raphe and nodules can be seen only when the valve is
+examined at right angles to its usual position.
+
+
+{113}RHOPALODIA VENTRICOSA (KUETZ.) MUELLER
+
+Valve gibbous in the middle on the dorsal side, straight on the ventral
+side, with reflexed apices; costæ, 7 in 10 µ; striæ, 14-16 in 10 µ. L.
+40-100 µ.
+
+The median nodule appears as a minute depression in the middle of the
+dorsal side. The two species usually occur together.
+
+_Epithemia gibba_ var. _ventricosa_ Kuetz.
+
+Pl. 31, Fig. 24.
+
+
+
+SURIRELLOIDEÆ
+
+The Surirelloideæ are usually understood to include the genera Surirella,
+Podocystis, Cymatopleura and Campylodiscus, all of which resemble each
+other more or less, either in having a keel or markings like the divisions
+of the keel in Surirella and a median line, or pseudoraphe. The genus
+Nitzschia also has a keel, but it does not border each side of the valve as
+in Surirella, being found either near one margin or between it and the
+centre. Certain of the Surirellæ are allied to the group Tryblionella of
+the Nitzschiæ, while forms of Stenopterobia are distinguished with
+difficulty from the group Sigmata.
+
+The following arrangement, therefore, is intended to include all genera
+having a keel or something which resembles it.
+
+_Hantzschia._--Valve asymmetrical; keels of the two valves opposite each
+other.
+
+_Nitzschia._--Valve asymmetrical; keels not (usually) opposite each other.
+
+_Surirella._--Valve usually symmetrical; a keel on each border.
+
+_Cymatopleura._--Valve without an elevated keel, but with markings like
+those of Surirella; undulated in zone view.
+
+_Campylodiscus._--Valves saddle-shaped.
+
+
+HANTZSCHIA GRUN. (1877)
+
+(named after C. A. Hantzsch)
+
+Valve arcuate, with rostrate ends; keel puncta short, prolonged into costæ
+or extending across the valve; median nodule rudimentary; the keels of the
+two valves opposite each other.
+
+Distinguished from Nitzschia chiefly by the position of the keels.
+According to Mereschkowsky, however, two species of Nitzschia, N.
+lanceolata and N. spectabilis, show the same peculiarity.
+
+Chromatophores four, two on each of the zones (Mereschkowsky).
+
+
+HANTZSCHIA AMPHIOXYS (EHR.) GRUN.
+
+Valve slightly arcuate, with rostrate apices; keel puncta, 8 in 10 µ; striæ
+transverse, 16-18 in 10 µ, punctate. L. 60 µ.
+
+Quite variable.
+
+Fresh water.
+
+Pl. 32, Fig. 9.
+
+
+{114}HANTZSCHIA AMPHIOXYS VAR. MAJOR GRUN.
+
+Valve as in type, but the keel puncta are 5 in 10 µ and the striæ are 11-12
+in 10 µ. L. 71 µ.
+
+H. amphioxys var. major Grun. is stated to be 120 µ in length. The present
+form is smaller but corresponds in puncta and striation. Van Heurck remarks
+that it approaches H. virgata.
+
+Abundant in sand ripples on the beach at Cape May, N. J.
+
+Pl. 39, Fig. 4.
+
+Fig. 6, Pl. 39, is drawn from an authentic specimen of Wm. Smith's
+Nitzschia amphioxys, from England, and is introduced for comparison. The
+central nodule is not evident.
+
+Fig. 3, Pl. 39, is from a specimen from an unknown locality. The keel
+puncta are 6 and the striæ 16 in 10 µ.
+
+
+HANTZSCHIA VIRGATA (ROPER) GRUN.
+
+Valve arcuate on the dorsal side, nearly straight on the ventral side, with
+rostrate, recurved apices; keel puncta prolonged to one-third the width of
+the valve, 4 in 10 µ; transverse striæ, 9-10 in 10 µ. L. 115 µ.
+
+Shark River, N. J. (Kain).
+
+I have not been able to find this form on our coast. The figure is drawn
+from a specimen from another locality.
+
+Pl. 32, Fig. 23.
+
+
+HANTZSCHIA MARINA (DONK.) GRUN.
+
+Valve with dorsal margin slightly arcuate, ventral margin straight; apices
+rostrate and recurved; keel puncta, 6 in 10 µ, prolonged into costæ across
+the entire valve; transverse striæ, 12 in 10 µ, in double rows of
+alternating puncta between the costæ. L. 106 µ.
+
+_Epithemia marina_ Donkin.
+
+Along the coast.
+
+Pl. 32, Fig. 22.
+
+
+NITZSCHIA HASSALL (1845), em. GRUN. (1880)
+
+(named after Christian L. Nitzsch, of Halle)
+
+Frustules usually free, sometimes enclosed in tubes or united into a
+filament. Valves keeled, the keels of the two valves usually diagonally
+opposite (see Hantzschia); keel puncta short or prolonged.
+
+According to Mereschkowsky, there are at least two endochrome plates placed
+transversely on the zones; sometimes there are from four to six plates, in
+one species twenty granules and in another no trace of any endochrome
+whatever.
+
+The following analysis is that of Grunow as given in Cleve and Grunow's
+"Arctic Diatoms," and adopted and illustrated by Van Heurck in his
+"Synopsis."
+
+
+GROUPS
+
+1. _Tryblionella._--Keel very excentric, valve often folded; keel puncta
+indistinct, usually the same in number as the striæ.
+
+2. _Panduriformes._--Valve broad, constricted in the middle, with more or
+less evident fold; keel very near the edge; keel puncta quite evident or
+apparently wanting.
+
+{115}3. _Apiculatæ._--Keel very near the edge; valve linear or somewhat
+narrower in the middle; striæ on the longitudinal fold fainter than on the
+remaining surface, or wanting; puncta not in quincunx.
+
+4. _Pseudo-Tryblionella._--Keel more or less close to the edge; valve with
+a more or less deep longitudinal fold over which the striæ are spread in
+the same way as over the remaining surface; keel puncta always distinct.
+
+5. _Circumsutæ._--Valve with more or less wide longitudinal fold; keel very
+excentric; keel puncta quite evident; surface of valve irregularly punctate
+and also traversed by rows of delicate puncta which belong to a different
+layer of the valve.
+
+6. _Dubiæ._--Like the group Pseudo-Tryblionella, but the valves are not so
+much folded; frustules sometimes narrowed in the middle. The separation of
+species is difficult and, in part, doubtful. Keel excentric.
+
+7. _Bilobatæ._--Like the group Dubiæ, but with more central keel and so
+forming a transition to the group Pseudo-Amphiprora; valves without
+longitudinal folds.
+
+8. _Pseudo-Amphiprora._--Valve with quite central, sharp keel, arcuate,
+without longitudinal fold; keel puncta always evident; frustule narrowed in
+the middle with more or less marked central nodule.
+
+Includes two species not found in this locality.
+
+9. _Perrya._--Valve arched with very sharp central keel; not narrowed in
+the middle; keel puncta mostly on short or long lines which are sometimes
+interrupted.
+
+Includes six species not found in this locality.
+
+10. _Epithemioideæ._--Keel excentric; keel puncta extended into costæ
+across the entire valve.
+
+11. _Grunowia._--As in the group Epithemioideæ, except that the costæ are
+shorter, not extending across the valve; keel very excentric.
+
+12. _Scalares._--Like Grunowia, but with sharper, somewhat excentric keel;
+transverse section of frustule quadrangular.
+
+13. _Insignes._--Like Scalares, but with more central keel so that many of
+the forms are near the group Perrya; frustule somewhat sigmoid.
+
+14. _Bacillaria._--Keel central or nearly so; valve somewhat arched; keel
+sharp, as in the group Insignes.
+
+15. _Vivaces._--Keel moderately excentric; valve, according to position,
+semi-lanceolate, with keel puncta in short rows, or lanceolate with quite
+central keel. The valves have in many positions a resemblance to
+Hantzschia, so that N. vivax frequently becomes confounded with a form of
+H. amphioxys. The median keel puncta are not distant and a central nodule
+is not evident as is the case in all species of Hantzschia.
+
+16. _Spathulatæ._--Like the group Bacillaria, but usually with very
+delicate striated valves; keel in valve view usually bordered with two
+parallel lines.
+
+17. _Dissipatæ._--Like Vivaces and Spathulatæ, but with smaller central
+keel and without parallel lines. Valves usually small, very delicately
+striated; no central nodule.
+
+18. _Sigmoideæ._--Keel quite central; no parallel lines; frustule sigmoid;
+valve without longitudinal furrow; keel puncta not extended; no central
+nodule evident.
+
+19. _Sigmata._--Like Sigmoideæ, but with a more excentric keel.
+
+20. _Obtusæ._--Like Sigmata, with a more or less excentric keel which has
+in the middle a small bending to the inside; middle keel puncta somewhat
+more distant than the others, and between them a central nodule evident.
+
+{116}21. _Spectabiles._--Valve large, slightly arcuate, with excentric
+keel; no longitudinal folds; keel puncta somewhat extended over the valve
+but much less than in the group Insignes, and often scarcely perceptible.
+
+22. _Lineares._--Keel somewhat excentric, but less than in Spectabiles;
+frustule straight, sometimes a little constricted in the middle, so that a
+transition is shown to the groups Dubiæ and Bilobatæ. Valve without
+longitudinal fold; keel puncta round or somewhat angular, scarcely
+extended.
+
+23. _Lanceolatæ._--Valve lanceolate, linear-lanceolate or rarely
+elliptical, with very excentric keel; not folded; keel puncta not extended.
+
+24. _Nitzschiella._--Valve with excentric keel and long, produced apices.
+
+
+TRYBLIONELLA
+
+NITZSCHIA TRYBLIONELLA HANTZSCH
+
+Valve elliptical-lanceolate, with subacute apices; longitudinal fold well
+marked; striæ coarse, transverse, 5 in 10 µ; indistinct puncta intermediate
+between the striæ. L. 45 µ. Quite variable.
+
+Blue clay.
+
+Pl. 32, Fig. 8.
+
+
+NITZSCHIA GRANULATA GRUN.
+
+Valve elliptical or elliptical-lanceolate; striæ in double rows, each row
+of three or four small puncta along the margin and rows of large puncta
+about 6 in 10 µ across the valve. L. 28-44 µ.
+
+Blue clay. Along the coast.
+
+Pl. 32, Fig. 3.
+
+
+NITZSCHIA NAVICULARIS (BRÉB.) GRUN.
+
+Valve elliptical-lanceolate, with acute apices; striæ on one side a double
+row of large and small puncta, and on the other side radiate short rows of
+large puncta, 7 in 10 µ; middle of valve hyaline. L. 35-60 µ.
+
+Blue clay. Not common.
+
+Pl. 32, Fig. 4.
+
+
+NITZSCHIA COMPRESSA (BAIL.)
+
+Valve elliptical-lanceolate, sometimes acuminate; striæ, 6 or 7 in 10 µ,
+coarsely punctate. L. 56 µ.
+
+_Pyxidicula compressa_ Bailey.
+
+_Nitzschia punctata_ (Wm. Sm.) Grun.
+
+_Tryblionella punctata_ Wm. Sm.
+
+Common along the coast.
+
+Pl. 39, Fig. 7.
+
+Var. minor (H. L. Smith).--Valve acuminate; striæ, 8 in 10 µ. L. 22 µ.
+
+_Pyxidicula compressa_ var. _minor_ H. L. Smith, Type Slide No. 431.
+
+Pl. 39, Fig. 8.
+
+The smaller forms occur northward, while the larger are found southward.
+This is unquestionably Bailey's form, as indicated by his figure and by the
+fact that it is found everywhere along the coast. Wm. Smith's T. punctata
+is the same species, although the puncta are smaller.
+
+
+{117}PANDURIFORMES
+
+NITZSCHIA PANDURIFORMIS GREG.
+
+Valve elliptical, constricted in the middle, with sub-cuneate apices;
+longitudinal fold, with a punctate longitudinal line; striæ transverse and
+oblique, 15 in 10 µ; keel puncta, 6 in 10 µ. L. 108 µ.
+
+Along the coast. More often found southward.
+
+Pl. 39, Fig. 2.
+
+
+NITZSCHIA PANDURIFORMIS VAR. MINOR GRUN.
+
+Valve elliptical, constricted in the middle, with cuneate apices; keel
+puncta, 9 in 10 µ; striæ in transverse and oblique lines about 20 in 10 µ;
+longitudinal fold bordered by a punctate line. L. 34 µ.
+
+Pavonia, N. J., artesian well.
+
+Pl. 32, Fig. 5.
+
+The var. continua Grun. is reported as occurring in Shark River. It varies
+in having the longitudinal fold punctate. It is also usually smaller than
+var. minor.
+
+
+APICULATÆ
+
+NITZSCHIA APICULATA (GREG.) GRUN.
+
+Valve oblong-linear, with cuneate-apiculate apices; striæ punctate,
+apparently interrupted or pervious, about 18 in 10 µ. L. 26 µ.
+
+Chester River, Md.
+
+Pl. 32, Fig. 6.
+
+The puncta are continued across the valve, but are less distinct on the
+fold. The figure shows the entire frustule with the fold on each valve. The
+valves are sometimes slightly constricted.
+
+
+NITZSCHIA ACUMINATA (WM. SM.) GRUN.
+
+Valve linear, sometimes slightly constricted in the middle, with acuminate
+apices; longitudinal fold entirely without or with indistinct striæ; keel
+puncta not evident; striæ, 14-15 in 10 µ. L. 82 µ.
+
+Port Penn, Delaware River.
+
+Pl. 32, Fig. 13.
+
+
+NITZSCHIA PLANA WM. SM.
+
+Valve linear; apices acute, slightly constricted in the middle;
+longitudinal fold further from the keel than the margin, broad, with
+scattered puncta; striæ subtle, irregular, interrupted, about 18 in 10 µ;
+keel puncta oblong, 3-6 in 10 µ. L. 100-170 µ.
+
+Blue clay. Along the coast.
+
+Pl. 32, Fig. 2.
+
+
+{118}PSEUDO-TRYBLIONELLA
+
+NITZSCHIA LITORALIS VAR. DELAWARENSIS GRUN.
+
+Valve linear, with obtusely rounded cuneate ends, scarcely, if at all,
+constricted in the middle; longitudinal fold wide; keel puncta, 5 or 6 in
+10 µ, sometimes confluent; striæ obscure, about 21 in 10 µ. L. 75 µ.
+
+Delaware River.
+
+Pl. 32, Fig. 12.
+
+This form is drawn from a slide of Christian Febiger containing an
+abundance of specimens from Delaware City, and marked "Nitzschia dubia."
+
+
+CIRCUMSUTÆ
+
+NITZSCHIA CIRCUMSUTA (BAIL.) GRUN.
+
+Valve elliptical, sometimes more than 200 µ in length; longitudinal fold
+more or less conspicuous; keel puncta about 4 in 10 µ, the middle distant
+with the appearance of a nodule; striæ irregular, subtle, finely punctate,
+frequently interrupted.
+
+_Surirella circumsuta_ Bail.
+
+_Tryblionella scutellum_ Wm. Sm.
+
+Common in brackish water.
+
+Pl. 32, Fig. 1.
+
+
+DUBIÆ
+
+NITZSCHIA DUBIA WM. SM.
+
+Valve linear, scarcely, if at all, constricted in the middle, with cuneate,
+produced, apiculate apices, somewhat recurved; keel very excentric; puncta
+sometimes partly prolonged, about 9 in 10 µ; striæ, 20-24 in 10 µ. L. 93 µ.
+
+Reported from along the New Jersey coast. I have not seen it. It is
+generally regarded as fresh-water. Slides sometimes labelled N. dubia are
+in reality N. litoralis var. delawarensis.
+
+Pl. 39, Fig. 5.
+
+The figure is drawn from a specimen from another locality.
+
+
+BILOBATÆ
+
+NITZSCHIA BILOBATA WM. SM.
+
+Valve linear-lanceolate, constricted in the middle, apiculate at the ends;
+keel puncta 6 in 10 µ, prolonged unequally across part of the valve, the
+two median sub-remote; striæ, 16 in 10 µ. Frustule oblong, truncate,
+constricted in the middle. L. 120 µ.
+
+Shark River, N. J., Chester River, Md.
+
+Pl. 32, Figs. 10 and 11.
+
+
+EPITHEMIOIDEÆ
+
+NITZSCHIA EPITHEMIOIDES GRUN.
+
+Valve linear, with cuneate, rostrate apices; slightly constricted on the
+keel side; keel puncta, 8 or 9 in 10 µ, extending as costæ across the
+valve; striæ delicate, 22 in 10 µ. L. 47 µ.
+
+Brackish water, Long Island Sound.
+
+Pl. 32, Fig. 21.
+
+
+{119}GRUNOWIA
+
+NITZSCHIA TABELLARIA GRUN.
+
+Valve rhomboidal, inflated in the middle; apices produced; keel puncta
+extend in costæ across half of the valve, 7 in 10 µ; striæ transverse,
+about 22 in 10 µ. L. 20 µ.
+
+_Dimerogramma sinuatum_ Thwaites.
+
+_Nitzschia sinuata_ var. _tabellaria_ (Grun.) V. H.
+
+Schuylkill River. Not common.
+
+Pl. 32, Fig. 7.
+
+
+SCALARES
+
+NITZSCHIA SCALARIS (EHR.) WM. SM.
+
+Valve linear, with obtusely conical apices; costæ transverse, extending
+more or less to one-third the width of the valve, 3 or 4 in 10 µ; striæ, 9
+or 10 in 10 µ, punctate. Length of valve quite variable, up to 480 µ
+(Cleve).
+
+A well-known form, abundant in salt marshes and more or less brackish
+water.
+
+Pl. 33, Fig. 6. (To the right of the figure is an outline of the valve
+reduced one-third.)
+
+
+INSIGNES
+
+NITZSCHIA INSIGNIS GREG.
+
+Valve nearly linear or linear-lanceolate; apices broad, slightly produced,
+obtuse; keel puncta extended into short costæ, 4 or 5 in 10 µ; striæ about
+14 in 10 µ. Length variable up to 400 µ.
+
+Delaware Bay.
+
+Pl. 33, Fig. 8.
+
+
+BACILLARIA
+
+NITZSCHIA PAXILLIFER (O. F. MUELLER) HEIBERG
+
+Frustules united in a filament, afterwards free; valve lanceolate with
+nearly central keel; keel puncta, 7-9 in 10 µ; striæ about 21 in 10 µ. L.
+110 µ.
+
+_Vibrio paxillifer_ O. F. Mueller.
+
+_Bacillaria paradoxa_ Gmelin.
+
+_Nitzschia paradoxa_ (Gmelin) Grun.
+
+Brackish water or streams subject to its influence.
+
+Pl. 33, Figs. 13 and 14.
+
+Otto Frederick Mueller, in 1786, published at Copenhagen a work on
+"Infusorial Animalcules," including a description of a Vibrio which he
+named paxillifer, obviously alluding to the partially-extended frustules
+bearing at the end a tablet-like bundle. Two years later, Gmelin described
+the same form as Bacillaria paradoxa, a name still used. Heiberg, however,
+in 1863, placed the form under Nitzschia where it properly belongs and
+called it Nitzschia paxillifer (O. F. Mueller). I have adopted Heiberg's
+name.
+
+Perhaps the most remarkable of all diatoms. Many species possess the power
+of motion, which, however, is evident only in the free frustule. In N.
+paxillifer, the movement of the frustules occurs without the loss of
+continuity or adherence to each other, so that, while at one time the
+adnate frustules form a narrow filament, like that of Fragilaria, at
+another {120}time they move laterally to their extreme length and form a
+thread of frustules adherent at their ends, later resuming their original
+position. The motion is repeated at intervals of from five to ten seconds.
+No satisfactory explanation of the movement has ever been made. In the
+filamentous form the frustules adhere to water-plants.
+
+
+VIVACES
+
+NITZSCHIA FLUMINENSIS GRUN.
+
+Valve lanceolate, apices produced; keel puncta, 4-6 in 10 µ, partly
+extended in short costæ; striæ transverse, 14-15 in 10 µ, punctate; keel
+without a pseudo-nodule. L. 73 µ.
+
+Common at Greenwich Point, Philadelphia.
+
+Pl. 32, Fig. 16.
+
+The form here figured is smaller than the type, which is from 130-160 µ in
+length.
+
+
+SPATHULATÆ
+
+NITZSCHIA SPATHULATA BRÉB.
+
+Frustule linear, truncate, dilated at the ends; zone with longitudinal
+folds; valve lanceolate, keel central; apices acute, with an elevated
+appendage; keel puncta, 5-6 in 10 µ; striæ very fine. L. 56 µ.
+
+Atlantic City and Cape May, N. J. (Lewis).
+
+Pl. 40, Fig. 3.
+
+
+DISSIPATÆ
+
+NITZSCHIA DISSIPATA (KUETZ.) GRUN.
+
+Valve lanceolate, with sub-rostrate apices; keel excentric; keel puncta
+about 6 in 10 µ; striæ, 14 in 10 µ. L. 20-40 µ.
+
+Fresh and brackish water.
+
+Pl. 40, Fig. 7.
+
+
+SIGMOIDEÆ
+
+NITZSCHIA MACILENTA GREG.
+
+Frustule sigmoid, truncate at the ends; valve linear, with sub-acute apices
+and nearly central keel; keel with 5-6 puncta in 10 µ; striæ obscure, about
+25 to 28 (?) in 10 µ. Length variable, up to 490 µ.
+
+As the valve is usually seen when the keel is on the margin, the outline
+(reduced one-third, shown to the left of the figure) is, as a rule,
+sigmoid.
+
+Delaware Bay.
+
+Pl. 33, Fig. 7.
+
+
+NITZSCHIA VERMICULARIS (KUETZ.) HANTZSCH
+
+Valve linear, sigmoid, attenuated toward the obtuse ends; keel puncta, 9 in
+10 µ, quite distinct; striæ very fine. L. 105 µ.
+
+Fresh-water pools.
+
+Pl. 32, Fig. 24; Pl. 33, Fig. 9.
+
+
+{121}SIGMATA
+
+NITZSCHIA SIGMA (KUETZ.) WM. SM.
+
+Frustule linear, sigmoid; valve linear, slightly sigmoid, tapering to the
+sub-acute apices; keel excentric, puncta, 8 in 10 µ; striæ, 20-24 in 10 µ.
+L. to 250 µ.
+
+Along the coast.
+
+Pl. 39, Fig. 13.
+
+
+NITZSCHIA SIGMATELLA GREG.
+
+Valve linear, sigmoid, slightly attenuated toward the obtuse apices; keel
+excentric, puncta, 8-10 (?) in 10 µ; striæ delicate, 25-30 in 10 µ. L. to
+400 µ. The keel puncta are quite obscure.
+
+_Nitzschia curvula_ Wm. Sm.
+
+_Nitzschia sigma_ var. _curvula_ (Wm. Sm.) De Toni.
+
+Fresh water. Hammonton Pond; May's Landing, N. J.
+
+Pl. 33, Figs. 4 and 5.
+
+Gregory remarks that the keel puncta are seen in some specimens. In both of
+the forms figured I have counted 30 striæ in 10 µ, but, after many
+examinations, I have not been quite certain about the keel puncta. The
+general appearance of the valves in any position is that of a Stenopterobia
+or Surirella anceps, with which it occurs.
+
+
+NITZSCHIA CLAUSII HANTZSCH
+
+Valve linear, slightly sigmoid, tapering to the sub-capitate ends; keel
+puncta, 11 in 10 µ; striæ subtle. L. 40 µ.
+
+Abundant in Ridley Creek, Delaware Co. (Palmer).
+
+Pl. 32, Fig. 20.
+
+
+OBTUSÆ
+
+NITZSCHIA OBTUSA WM. SM.
+
+Frustule sigmoid, rounded at the ends; keel somewhat excentric, inflexed in
+the middle, the two median puncta distant; keel puncta, 5-6 in 10 µ; striæ,
+26 in 10 µ. L. to 300 µ.
+
+Along the coast.
+
+Pl. 39, Fig. 16.
+
+
+NITZSCHIA OBTUSA VAR. FLEXELLA H. L. SMITH
+
+Valve more attenuate at the ends than the type and smaller.
+
+Pl. 39, Fig. 14.
+
+
+NITZSCHIA OBTUSA VAR. SCALPELLIFORMIS GRUN.
+
+Valve linear, with apices unilaterally truncate; keel excentric; keel
+puncta, 8 in 10 µ; striæ, 26 in 10 µ. L. 48 µ.
+
+Along the coast.
+
+Pl. 32, Fig. 17.
+
+
+{122}SPECTABILES
+
+NITZSCHIA SPECTABILIS VAR. AMERICANA GRUN.
+
+Frustule linear, slightly constricted in the middle, with sub-cuneate ends;
+valve linear, slightly arcuate, tapering to the sub-rostrate ends; keel
+excentric, keel puncta sometimes confluent, 4-6 in 10 µ, prolonged into
+short costæ; striæ distinct, 14 in the middle, 18 at the ends in 10 µ (but
+variable in different specimens). L. 186 µ.
+
+Blue clay, especially at Tioga St.
+
+Pl. 33, Fig. 3; Pl. 39, Fig. 1.
+
+This is, probably, one of the most beautiful of the Nitzschiæ. It
+sometimes, according to De Toni, reaches a length of 520 µ.
+
+Grunow states that his variety is found in the S. Bridgeton deposit. In a
+slide of Moeller labelled "Bridgeton, Maine," I find specimens identical in
+every respect with the Philadelphia form.
+
+
+LINEARES
+
+NITZSCHIA LINEARIS (AG.) WM. SM.
+
+Valve linear, slightly inflexed in the middle; keel excentric; keel puncta,
+8-9 in 10 µ, the two median distant; striæ about 30 in 10 µ. Frustules in
+zone view narrowed toward the ends, truncate. L. 75 µ.
+
+Very common in fresh water.
+
+Pl. 32, Fig. 18. Fig. 20, Pl. 40, a transverse section of frustule.
+
+
+LANCEOLATÆ
+
+NITZSCHIA PALEA (KUETZ.) WM. SM.
+
+Valve linear-lanceolate, slightly rostrate at the apices; keel puncta, 10
+in 10 µ, the median not distant; striæ, 33-36 in 10 µ; zone view linear,
+with rounded ends. L. 25-65 µ.
+
+Fresh water.
+
+Pl. 32, Fig. 15.
+
+
+NITZSCHIA AMPHIBIA GRUN.
+
+Valve lanceolate, apices sometimes slightly produced, rounded; keel puncta,
+8-9 in 10 µ; striæ, 16 in 10 µ. L. 20-32 µ.
+
+Fresh water.
+
+Pl. 32, Figs. 14 and 25.
+
+
+NITZSCHIA COMMUNIS RAB.
+
+Frustule linear, slightly attenuated at the obtuse ends; valve
+elliptical-lanceolate, attenuated toward the obtuse ends; keel puncta, 12
+in 10 µ; striæ more than 30 in 10 µ. L. 35 µ.
+
+Fresh water.
+
+Pl. 32, Fig. 19.
+
+
+NITZSCHIA INTERMEDIA HANTZSCH
+
+Valve linear-lanceolate; keel puncta, 8 in 10 µ; striæ about 24 in 10 µ. L.
+100 µ.
+
+Crum Creek. Not common.
+
+Pl. 33, Fig. 2.
+
+
+{123}NITZSCHIELLA
+
+NITZSCHIA LONGISSIMA (BRÉB.) RALFS
+
+Valve linear-lanceolate, with exceedingly long horns or beaks; keel puncta
+about 10 in 10 µ; striæ about 16 in 10 µ. L. to 500 µ.
+
+Shark River, N. J.
+
+Pl. 33, Fig. 1.
+
+Forma parva V. H.--Keel puncta, 10-12 in 10 µ. L. 70 µ.
+
+East Park Reservoir, Philadelphia.
+
+Pl. 33, Fig. 10.
+
+Differs from N. closterium (Ehr.) Wm. Sm. in the keel puncta.
+
+The type form occurs in brackish and salt water. The occurrence of the
+variety in fresh water is another instance of the finding of presumably
+brackish forms in the water supply of the city. If these cases prove to be
+unusual, it may be because of one of two reasons. The Schuylkill River,
+before the building of the dam at Fairmount, was tidal as far as the Falls
+of Schuylkill, and brackish influences, while not now existent, may have
+caused the growth of forms which now survive. Another reason may be that
+the opening of the locks at Fairmount Dam may cause a slight admission of
+brackish forms from tidal water below. The abundance of the brackish
+species appears to indicate that the first reason is the more plausible.
+
+
+NITZSCHIA REVERSA WM. SM.
+
+Valve lanceolate extended into beaks or horns curving in opposite
+directions; keel puncta not evident; striæ, "20-26" in 10 µ. L. 70 µ.
+
+Brackish water. Abundant in Duck Creek, Delaware River.
+
+Pl. 33, Fig. 11.
+
+
+NITZSCHIA ACICULARIS (KUETZ.) WM. SM.
+
+Valve lanceolate, with beaks or horns about half the length of the median
+part of the valve; keel puncta, 18 in 10 µ; striæ exceedingly delicate,
+"about 40 in 10 µ." L. 45 µ.
+
+Fresh water. Darby Creek.
+
+Pl. 33, Fig. 12.
+
+
+HOMOEOCLADIA AG. (1827)
+
+(homoios, like, and clados, a branch)
+
+Frustules like Nitzschia, but enclosed in branching or simple tubes.
+
+
+HOMOEOCLADIA FILIFORMIS WM. SM.
+
+Frustule linear, tumid in the middle, obtuse at the ends; valve
+linear-lanceolate, with somewhat acute apices; keel central or nearly so;
+keel puncta, 8 in 10 µ; striæ delicate. L. 108 µ.
+
+Fresh and brackish water. Newark, N. J.
+
+Pl. 33, Fig. 15.
+
+
+{124}SURIRELLA TURPIN (1828)
+
+(named after Dr. Suriray, a physician of Havre)
+
+Valve linear, elliptical or ovate; pseudoraphe linear or lanceolate; a
+marginal keel forming wings or alæ seen in zone view; costæ short or
+reaching the pseudoraphe, frequently with intercostal striæ more or less
+evident.
+
+The genus is divided by Grunow according to the length and form of the
+costæ. I include Stenopterobia.
+
+Section 1.--Costæ of nearly equal width throughout, reaching the
+pseudoraphe.
+
+Section 2.--Costæ short or marginal.
+
+Section 3.--Costæ dilated at the margin, attenuated toward the pseudoraphe.
+
+Section 4.--Valve having the appearance of Nitzschia, with inconspicuous
+alæ (Stenopterobia).
+
+The endochrome consists of two laminate chromatophores, one on each valve.
+
+The auxospores are single, originating from the union of two frustules (H.
+L. Smith).
+
+
+SECTION 1
+
+SURIRELLA BISERIATA (EHR.) BRÉB.
+
+Valve lanceolate, subacute at the ends; costæ robust, about 2 in 10 µ,
+parallel in the middle, radiate at the ends; pseudoraphe narrow. L. 100 µ.
+
+_Surirella bifrons_ Ehr.
+
+Fresh water.
+
+Pl. 39, Fig. 12; Pl. 35, Fig. 2 (smaller form).
+
+
+SURIRELLA LINEARIS WM. SM.
+
+Valve linear, with cuneate ends, slightly constricted in the middle; costæ
+parallel, 2-3 in 10 µ. L. 90 µ.
+
+Fresh water.
+
+Pl. 35, Fig. 8.
+
+
+SURIRELLA AMPHIOXYS WM. SM.
+
+Valve oblong-linear, with cuneate ends; pseudoraphe narrow; costæ, 3-4 in
+10 µ; striæ, 14-16 in 10 µ, somewhat radiate. L. 34-54 µ.
+
+_Surirella moelleriana_ Grun.
+
+Fresh and brackish water. Common along the coast.
+
+Pl. 35, Figs. 12 and 13.
+
+
+SURIRELLA ROBUSTA EHR.
+
+Valve linear-ovate; pseudoraphe wide; alæ prominent; costæ wide, 1¼ in 10
+µ. Frustule in zone view clavate. L. 200-365 µ.
+
+Fresh water.
+
+Pl. 36, Fig. 2.
+
+
+{125}SURIRELLA SPLENDIDA (EHR.) KUETZ.
+
+Valve ovate; costæ, 1½ to 2 in 10 µ; pseudoraphe linear, narrow. L. 125-200
+µ.
+
+Fresh water.
+
+Pl. 35, Fig. 3.
+
+S. splendida is smaller than S. robusta and wider in proportion, but, as
+intermediate forms occur, it is difficult to distinguish between them.
+
+
+SURIRELLA ELEGANS EHR.
+
+Valve ovate, rounded at one end and acute at the other; pseudoraphe
+lanceolate, narrow; costæ, 1½ in 10 µ; striæ subtle, 22 in 10 µ. Frustule
+in zone view cuneate. L. 180-220 µ.
+
+Fresh water.
+
+Pl. 36, Fig. 1.
+
+
+SURIRELLA STRIATULA TURPIN
+
+Valve broad, obovate or elliptical, rounded at each end; costæ, 1¼ in 10 µ,
+curved at the ends; striæ, 14 in 10 µ. Frustule in zone view cuneate;
+marginal alæ quite robust. L. 100-160 µ.
+
+Blue clay. Brackish water.
+
+Pl. 34, Fig. 1.
+
+In the specimen figured, the outline is exactly elliptical, although the
+species is usually conical at one end.
+
+
+SURIRELLA GEMMA EHR.
+
+Valve ovate or ovate-elliptical, rounded at each end, sometimes
+asymmetrical along the longitudinal axis; pseudoraphe very narrow; costæ
+distant, at irregular intervals, about 2 in 10 µ, somewhat radiate,
+reaching the pseudoraphe; striæ, 20 in 10 µ, punctate. Frustule in zone
+view cuneate. L. 70-120 µ.
+
+Along the coast.
+
+Pl. 36, Fig. 4.
+
+
+SURIRELLA TENERA GREG.
+
+Valve ovate; pseudoraphe narrow, well-defined; costæ indistinct, 2½ in 10
+µ, their margins invisible; striæ about 14 in 10 µ, punctate, more evident
+near the margin. L. 90 µ.
+
+_Surirella diaphana_ Bleisch.
+
+Pavonia, N. J., artesian well.
+
+Pl. 35, Fig. 6.
+
+The figure is that of the var. nervosa A. S. (Atlas, Pl. 23, Fig. 15),
+which differs from the type in having the position of the costæ indicated
+by scattered puncta.
+
+
+{126}SECTION 2
+
+SURIRELLA GUATIMALENSIS EHR.
+
+Valve ovate; pseudoraphe very narrow and indistinct; costæ short, marginal,
+2-2½ in 10 µ, absent from the rounded end. L. 120 µ.
+
+_Surirella cardinalis_ Kitton.
+
+Smith's Island, Delaware River.
+
+Pl. 36, Fig. 5.
+
+
+SURIRELLA OVALIS BRÉB.
+
+Valve ovate; costæ short, marginal, radiate, 3-6 in 10 µ, often unequal;
+central area ovate, indistinctly costate; striæ scarcely visible, about 18
+in 10 µ; pseudoraphe narrow. L. 45-93 µ.
+
+_Surirella davidsonii_ A. S.
+
+Fresh or brackish water.
+
+Pl. 35, Fig. 5; Pl. 39, Fig. 11.
+
+The smaller specimen is from the Delaware River, and the larger from the
+Hudson River.
+
+
+SURIRELLA CRUMENA BRÉB.
+
+Valve nearly orbicular; costæ short, marginal, radiate; pseudoraphe narrow,
+indistinct; central area indistinctly costate, sometimes interrupted.
+
+On account of the extreme confusion in the names of many forms which appear
+to be variations of S. ovalis, I have followed Van Heurck in retaining the
+original names as specific. De Toni gives S. crumena as a variety of S.
+ovalis.
+
+Fresh and brackish water. Quite common in the Delaware River.
+
+Pl. 35, Fig. 4.
+
+
+SURIRELLA PINNATA WM. SM.
+
+Valve ovate or oblong-ovate; costæ reaching the linear pseudoraphe, about 6
+in 10 µ. L. 40 µ.
+
+_Surirella ovalis_ var. _pinnata_ (Wm. Sm.) De Toni.
+
+S. pinnata is the type of a number of small forms usually found together,
+including S. panduriformis, S. angusta and S. minuta.
+
+Fresh water. Media (Palmer).
+
+Pl. 36, Fig. 7; Fig. 9 (abnormal).
+
+Var. minuta, a small form of S. pinnata, occurs with the type.
+
+
+SURIRELLA PANDURIFORMIS WM. SM.
+
+Valve linear-oblong, with rounded ends, more or less constricted in the
+middle; otherwise as in S. pinnata. L. 54 µ.
+
+Fresh water.
+
+Pl. 36, Fig. 6.
+
+
+{127}SURIRELLA ANGUSTA KUETZ.
+
+Valve linear, with cuneate ends; otherwise as in S. pinnata.
+
+Fresh water.
+
+Pl. 36, Fig. 8.
+
+S. pinnata, S. panduriformis, and S. angusta have a narrow central area,
+and differ from S. ovalis which has short costæ.
+
+
+SURIRELLA OBLONGA EHR. ?
+
+Valve elliptical-lanceolate, with obtuse ends; costæ, marginal, 2½ in 10 µ;
+median area granulate; pseudoraphe narrow, lanceolate, scarcely visible;
+striæ about 18 in 10 µ. L. 60 µ.
+
+Blue clay. Rare.
+
+Pl. 35, Fig. 9.
+
+This has the outline and appearance of S. oblonga Ehr. (Mik. Pl. 15, Fig.
+48), but the costæ are closer.
+
+
+SURIRELLA RECEDENS A. S.
+
+Valve ovate; costæ, 2-2½ in 10 µ; pseudoraphe narrow, not reaching the ends
+of the valve; intercostal spaces more evident near the middle. L. 50 µ.
+
+Blue clay. Not uncommon.
+
+Pl. 35, Fig. 7.
+
+
+SURIRELLA CRUCIATA A. S.
+
+Valve ovate; pseudoraphe very narrow; costæ, 2 in 10 µ; the outline of
+several of the median costæ strongly emphasized, while the other costæ are
+indistinct. L. 54 µ.
+
+Blue clay.
+
+Pl. 35, Fig. 10.
+
+
+SURIRELLA GRACILIS GRUN.
+
+Valve linear, with sub-cuneate ends, slightly constricted in the middle;
+pseudoraphe very narrow; costæ, 6-7 in 10 µ; transverse striæ about 26 in
+10 µ, punctate. L. 75 µ.
+
+According to De Toni (p. 598), this form is a Nitzschia. It has, however, a
+narrow pseudoraphe.
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 35, Fig. 11.
+
+
+SECTION 3
+
+SURIRELLA FASTUOSA EHR.
+
+Valve ovate; costæ about 1-2 in 10 µ, dilated at the margin and contracting
+at about one-fourth the distance toward the middle; area, ovate-lanceolate;
+pseudoraphe, narrow and indistinct; intercostate striæ more evident near
+the margin, 19 in 10 µ, becoming again evident in a narrow band about
+one-half the distance to the pseudoraphe. L. 50-120 µ.
+
+Along the coast. More common southward.
+
+Pl. 35, Fig. 1.
+
+
+{128}SURIRELLA FEBIGERII LEWIS
+
+Valve ovate-lanceolate; costæ about 2½ in 10 µ with punctate interspaces
+extending half the distance toward the median hyaline area, which is
+divided longitudinally on each side of the narrow pseudoraphe by two
+longitudinal bands composed of short, transverse, irregular, punctate
+lines.
+
+Along the coast.
+
+Pl. 36, Fig. 3.
+
+
+SECTION 4 (STENOPTEROBIA)
+
+SURIRELLA ANCEPS LEWIS
+
+Frustule linear, straight or nearly so; valve sigmoid with rounded apices;
+costæ marginal, nearly obsolete; striæ distinct, about 15 in 10 µ;
+pseudoraphe wide. L. to 320 µ.
+
+Hammonton Pond and Tom's River, N. J.
+
+Pl. 34, Fig. 2.
+
+
+SURIRELLA INTERMEDIA LEWIS
+
+Frustule linear, straight, widened at the truncate ends; valve linear,
+sigmoid, tapering to the sub-acute ends; costæ about 5 in 10 µ; striæ about
+20 in 10 µ. L. variable.
+
+Hammonton Pond, N. J.
+
+Pl. 34, Fig. 3; Pl. 39, Fig. 9 (zone view).
+
+This, perhaps, is forma sub-acuta Fricke.
+
+Fig. 7, Pl. 34, is probably a small form of S. intermedia, from Willistown,
+Pa. It resembles a Nitzschia.
+
+
+SURIRELLA DELICATISSIMA LEWIS
+
+Frustule linear, rounded at the ends; valve linear-lanceolate, sometimes
+very slightly constricted in the middle, with acute apices; costæ, 5 in 10
+µ; striæ about 20 in 10 µ; pseudoraphe well defined, lanceolate. L. to 90
+µ.
+
+Fresh water. Newtown Square.
+
+Pl. 34, Figs. 5 and 6 (small forms).
+
+
+SURIRELLA ARCTISSIMA A. S.
+
+Valve linear, tapering to the sub-acute ends; costæ marginal, 5 in 10 µ;
+striæ, 18 in 10 µ; pseudoraphe not evident. L. 184 µ.
+
+May's Landing, N. J.
+
+Pl. 34, Fig. 4.
+
+Fig. 10, Pl. 39, is a small form from Newtown Square, Pa., in which the
+length is 86 µ, the costæ 5 and the striæ 16 in 10 µ.
+
+
+PODOCYSTIS KUETZ. (1844)
+
+(pous, a foot, and cystis, a bag)
+
+Frustules cuneate, similar to Surirella, but attached by short stipes to
+other algæ; valve obovate.
+
+
+{129}PODOCYSTIS ADRIATICA KUETZ.
+
+Valve nearly symmetrical, obovate, with transverse costæ about 4 in 10 µ,
+alternating with double rows of coarse puncta; median line distinct,
+linear. L. 43 µ.
+
+_Podocystis americana_ Bail.
+
+Hell Gate, N. Y.
+
+Pl. 40, Fig. 6.
+
+
+CYMATOPLEURA WM. SM. (1851)
+
+(cuma, a wave, and pleura, a side)
+
+Valve elliptical; surface transversely undulate, with short, marginal
+costæ. Frustule in zone view linear, with undulated sides.
+
+Auxospore formation as in Surirella.
+
+
+CYMATOPLEURA SOLEA (BRÉB.) WM. SM.
+
+Valve oblong, with cuneate apices, constricted in the middle; costæ about 6
+in 10 µ; striæ, 10 in 10 µ; pseudoraphe scarcely visible. L. 50-300 µ.
+
+Blue clay. Common in the Hudson River.
+
+Pl. 34, Figs. 8 and 9.
+
+
+CYMATOPLEURA ELLIPTICA (BRÉB.) WM. SM.
+
+Valve elliptical; marginal costæ short, 3 in 10 µ; striæ delicate, 18 in 10
+µ; undulations four or more. L. 70-140 µ.
+
+Blue clay.
+
+Pl. 37, Fig. 1.
+
+_Forma spiralis._--Valve ovate, swelled into curved ridges at the lower
+end, with a contraction of the valve.
+
+Port Penn, Delaware River.
+
+Pl. 37, Fig. 2.
+
+
+CYMATOPLEURA MARINA LEWIS
+
+Frustule linear, with numerous undulations, ends apiculate; valve
+linear-lanceolate, with acute ends; striæ transverse, punctate at unequal
+intervals, from 16-18 in 10 µ. L. 43 µ.
+
+East River, N. Y.
+
+Pl. 37, Figs. 3 and 4.
+
+Lewis states that the ends are more or less truncate. I do not find them
+so.
+
+
+CAMPYLODISCUS EHR. (1841)
+
+(campulos, curved like a saddle)
+
+Valve orbicular or sub-orbicular, with costæ or punctate rays converging
+from the circumference toward the hyaline centre, which sometimes appears
+like a pseudoraphe. Frustule of two saddle-shaped valves at right angles to
+each other. The zone view may be of almost any shape according to position.
+
+Endochrome consists of two bands, each lining the inner surface of each
+valve. Auxospore and conjugation unknown.
+
+
+{130}CAMPYLODISCUS ECHENEIS EHR.
+
+Valve sub-orbicular, saddle-shaped; costæ indistinct, short, marginal; rows
+of round or elongated puncta converge toward the lanceolate, hyaline median
+space. Diam. 80-140 µ.
+
+_Campylodiscus argus_ Bail.
+
+Blue clay. Reservoir at Thompson and Twenty-sixth Sts., Phila.
+
+Pl. 37, Fig. 6.
+
+This form, usually considered as brackish and marine, is occasionally found
+in fresh water. According to Deby, it is fossil in the "Champlain deposit
+of N. A."
+
+
+CAMPYLODISCUS HIBERNICUS EHR.
+
+Valve irregularly orbicular; costæ, 40-60, about 2 in 10 µ, wide at the
+margin and attenuated toward the centre which is somewhat quadrate; the
+radials rough with minute apiculi.
+
+Pensauken, N. J., artesian well.
+
+Pl. 37, Fig. 5.
+
+
+
+{131}APPENDIX
+
+
+COLLECTION AND PREPARATION OF DIATOMS
+
+It is assumed that every student of the Diatomaceæ has a general knowledge
+of the collection, preparation, mounting and examination of material. For
+the novice, however, the following methods, used by the author for many
+years, may be of service.
+
+_Collection of Fresh-water Material._--The yellow film on the inside of
+aquaria always contains small species. Stems of water-plants near the
+shores of ponds and the submerged roots, the brownish coating of rocks in
+streams and water-falls, fountains, and water-troughs, are prolific. At all
+times of the year, some diatoms may be found in a thin layer upon the mud
+of rivers or creeks. In the spring, brown patches of mud, filled with
+bubbles, floating near the shore in ponds, or coming down with the current
+in rivers, are rich in various forms. Within the limits assigned to our
+district, I have made collections in the following localities: Schuylkill
+River, including the region near Fairmount Dam, several reservoirs and the
+water-supply; the Wissahickon and Fairmount Park, Darby, Crum and Ridley
+Creeks, the Neshaminy and the Brandywine; meadow pools and rivulets near
+the city; the upper Delaware, the Water Gap and numerous cascades
+northward; the Shawangunk Mountains and the Poconos; many parts of New
+Jersey along the coast; the Pine Barren region, the Hammonton, Atsion and
+Kirkwood Ponds and the swamps near Atco.
+
+In the collection of fresh-water material, it is well to be provided with a
+number of small bottles. Take a handful of the water-plants or algæ, and
+squeeze the material into the bottles, or, lacking a bottle, wrap it in
+paper. With a small forceps it is possible to detach minute quantities of a
+pure gathering which may not need further preparation beyond burning to a
+red heat on the cover-glass before mounting. A malacca cane, with extending
+rod to which may be screwed a bottle, net, spoon or hook, is useful on a
+long trip. If it is impossible to separate the thin film of diatoms from
+the mud in the bed of streams, dip up the surface mud with one bottle,
+allow to settle a few minutes, then pour off the supernatant liquid, which
+will be comparatively free from sand, into another bottle. It must be
+confessed, however, that the mud in streams near Philadelphia contains a
+large quantity of fine mica which, in some instances, it is impossible to
+remove.
+
+_Collection of Marine Material._--Shell scrapings, the stomachs of fish,
+marine algæ, especially the brown and red algæ, the hulls of vessels, mud
+from anchors and dredgings, are all sources which may prove valuable. In
+the sand ripples, after the tide recedes, a yellowish-brown deposit will be
+noticed. This should be taken up carefully with a spoon and placed in a
+bottle; the sand will settle at once and a very pure gathering will be held
+in suspension in the water. Such collections may be made along the entire
+coast of New Jersey on sunny days in summer. In salt meadows near Absecon
+and Hackensack, large quantities of diatoms, including Pleurosigma, may be
+obtained in the yellow scum floating on the surface.
+
+_The Blue Clay Deposit._--The blue clay occurs as a pre- or post-glacial
+deposit in the bed of the ancient Delaware River, and, at depths varying
+usually from fifteen to forty feet below the surface, has been obtained
+from artesian wells at Pavonia, Pensauken and Gloucester, N. J., also at
+Port Penn on the Delaware, and especially from the dredgings {132}made by
+the removal of Smith's Island opposite the city. In the city proper, it may
+be stated briefly that material may be found in a stratum of very light
+blue clay at a depth varying from twenty to sixty feet in many places south
+of Arch St. east of Broad St., and also along the beds of ancient rivulets
+near Tioga St., at Sixteenth St., and in certain other places which were
+probably subject to tidal overflow. One of the best collections was made
+along the bank of the Schuylkill at the east end of Walnut St. Bridge, at a
+depth of thirteen feet below the surface. Excavations for the Reading
+Terminal and the Subway and several buildings, as the Bingham House, have
+furnished numerous specimens.
+
+_Cleaning the Material._--Some gatherings may be so pure as to be ready for
+mounting when treated with dilute alcohol and oil of cloves. If, when
+gathered, the diatoms are immersed in a saturated solution of picric acid
+for several days, they may be stained with carmine or methylene blue, or
+whatever may be required to emphasize the contents of the frustules,
+including the endochrome and the pyrenoids. After staining, pass as rapidly
+as expedient through the treatment with dilute alcohol and oil of cloves,
+and mount in benzol balsam, avoiding heat. A hot solution of mercuric
+bichloride is sometimes used for the preservation of the endochrome,
+although washing is needed before mounting. For the particular stain
+considered best for certain details of structure, it will be advisable to
+consult works on Micro-Chemistry or Heinzerling (_l. c._). The stains of
+most importance are carmine, methylene blue, hæmatoxylin, gold chloride and
+Bismarck brown.
+
+Whatever method may be used in staining, the identification of forms is
+impossible, in most cases, unless the valves are carefully cleaned and the
+cell-contents destroyed. For this purpose provide a casserole holding from
+five to eight ounces, an iron tripod stand with alcohol lamp, several
+six-inch test-tubes, preferably those with a standard base, fitted with
+pure rubber corks. Take the material as free from twigs, dead leaves, sand,
+and other matter as possible, place it in the casserole, and add about the
+same quantity of nitric acid. Boil for twenty minutes and then add about
+half a teaspoonful of powdered bichromate of potash, stirring with a glass
+rod. Then take a beaker-glass partly filled with water and pour into it
+slowly the liquid which has been allowed to cool a short time, whirling the
+casserole to cause the concentration of sand in the centre. Allow the
+material to settle for half an hour or longer, according to the amount of
+diatoms and their size. Pour off the water, add more water, and place in a
+test-tube. Repeat the decantation, shaking the test-tube, closed with a
+rubber cork, vigorously each time. From time to time whirl the diatoms in
+the casserole and throw away the sand collected in the centre. By repeating
+the decantation, shaking and whirling, the deposit will be found to consist
+almost entirely of diatoms. It may be necessary to repeat the boiling in
+the acid and bichromate. If, however, any detritus other than sand is
+noted, boil in sulphuric acid and add from time to time minute pinches of
+powdered chlorate of potash, being careful to protect the eyes by holding a
+piece of glass before them; otherwise the explosions which occur are likely
+to throw some of the boiling acid into the eyes and destroy the sight. The
+material, when clean, should be white or, in the case of Synedra,
+yellowish. It is quite easy to construct a box fitted with the proper
+apparatus for boiling and provided with a glass door for observation, and a
+method of introducing the chlorate of potash through a small aperture or
+tube. The box may be placed in the garden or fastened outside of a window
+so that the poisonous fumes may be carried off.
+
+An excellent method, in the case of larger forms, is to boil the material
+already cleaned by the acid in water to which a few shavings of coarse
+brown soap are added. The difference in density will hold in suspension any
+flocculent matter, and while many of the smaller {133}forms will not
+settle, the others will be perfectly cleaned. When satisfied with the
+cleaning, preserve the stock material in part alcohol and, in using, pour
+into a smaller bottle the amount required, replace the dilute alcohol with
+distilled water, and mount as directed. It often happens that gatherings
+are made consisting almost entirely of sand. Attempts at cleaning in the
+usual way will cause the loss of nearly all of the diatoms. In this case,
+after the material has been treated with acid until nothing remains but
+sand and a few diatoms, the mechanical finger must be used.
+
+In the cleaning of marine deposits, various methods may be required. In the
+case of partly siliceous species, washing in pure water repeatedly is all
+that can be done. The larger and heavier diatoms may be separated from the
+sand by elutriation or by whirling in a casserole, by rocking in a shallow
+dish the shape of a watch crystal, or by pouring slowly over a strip of
+plate-glass at least two feet in length inclined at an angle of thirty
+degrees. The sand will cling to the glass, while the greater portion of the
+diatoms will run off. Where particles of shells or foraminifera are
+present, a preliminary boiling in hydrochloric acid is advisable. In all
+marine gatherings, the salt should first be washed out before proceeding
+with the cleaning.
+
+For hardened masses of clay and for fossil deposits, it is necessary to
+boil in carbonate of soda and follow with the acid treatment. Citric acid
+and acetate of potash used alternately in boiling may be tried. Soaking for
+a time in acetate of potash and allowing the material to deliquesce for a
+week before further process, has proved successful in some instances. The
+repetition of several methods and the gentle breaking of the harder masses
+with the point of a needle will disintegrate almost any diatomaceous earth,
+but, as a last resort for refractory deposits, boil in pure water, add a
+piece of caustic potash about the size of a pea, continue the boiling not
+more than thirty seconds longer, and pour instantly into dilute
+hydrochloric acid; otherwise the diatoms will be destroyed. Afterwards
+proceed with the usual treatment.
+
+_Slides and Covers._--Take half an ounce of No. 1 covers, circles, and
+place them in a wide-mouthed bottle. Add a portion of the following mixture
+(Dr. Carl Seiler's formula):
+
+  Bichromate of potash    2 oz.
+  Sulphuric acid          3 fl. oz.
+  Water                   25 fl. oz.
+
+Shake the bottle in order that the surfaces of the covers may be fully
+exposed to the action of the acid, and set aside for several hours. Decant
+the solution, add water repeatedly until all traces of the mixture are
+removed, and keep the circles in the bottle in fifty-per cent. alcohol.
+When needed, take out a circle with forceps and dry on a linen cloth.
+
+The slides may be treated in the same way, or they may be easily prepared
+by immersion in a solution of washing soda, and then washed and dried. This
+process may be used in cleaning the balsam or styrax from old slides.
+
+_Preparation of Strewn Mounts._--Place several covers on the mounting
+stand. With a dipping tube, cover each circle with distilled water, and add
+a small drop of the prepared diatoms, being careful to avoid any vibration
+of the stand. Heat the stand until small bubbles begin to appear, remove
+the lamp, and allow the water to evaporate. If the above method is
+carefully followed, the diatoms will be deposited in an even layer,
+provided the material is not too dense. Take a slide, centre it, and place
+a small amount of styrax on the centre. Invert the prepared cover, and
+gently place it upon the styrax. Heat the slide {134}on the mounting stand
+until the styrax bubbles and then allow to cool. If bubbles still remain,
+heat again until they disappear. It is well to mount several slides more
+than required, as some may be imperfect.
+
+_Preparation of Selected Mounts._--Take a slide, place a minute quantity of
+beeswax on two places at a distance apart nearly equal to the diameter of
+the cover used. Place a cover on the wax and press it down flat, or
+sufficiently to keep it in position. Dip a fine needle into the following
+cement:
+
+  Glacial acetic acid    12 drachms
+  Gelatine                2 drachms
+  Alcohol                 1 drachm
+
+This is made by adding the acid to the gelatine in a water-bath and then
+the alcohol, and filtering. Apply the moistened needle to the centre of the
+cover and spread as small a quantity as possible in a thin layer. Now place
+the slide upon the turn table, centre it with respect to the position of
+the gelatine, and with the finest sable brush draw a circle about a tenth
+of an inch in diameter around the gelatine in water-color (Windsor), blue
+or vermilion, or in India ink. Instead of the water-color, a circle of
+tin-foil the size of the cover and pierced with a hole in the centre may be
+used, but the colored circle is to be preferred, as, when brought into
+view, it indicates exactly the focus required for observing the diatom.
+
+The bottle containing the cleaned material, which has been kept in water
+and alcohol, should be refilled with distilled water and well shaken, when
+a small portion may be taken up with a dipping tube and evenly distributed
+over a portion of a slide and then dried. By the use of a mechanical
+finger, fitted with a small piece of finely spun glass attached by wax to
+the holder of the finger, when the microscope is focussed until the glass
+thread touches the diatom selected, it will adhere to the thread. Raise the
+body of the microscope, remove the slide containing the spread material, or
+move it to another part of the stage, and place the slide with the prepared
+cover in the same position. Now carefully lower the body-tube of the
+instrument until the diatom rests upon the gelatine, breathe gently upon
+it, remove the cover from the slide, invert it over another slide
+containing a drop of styrax and proceed by heating to mount as before. The
+size of the diatom, the amount of gelatine, and several other factors, will
+enter into the question of success or failure. I have, however, employed
+the above method and have mounted thousands of slides of selected diatoms
+successfully. It is necessary to avoid any air current which will cause the
+diatom to fall from the thread. On very cold days the glass thread
+sometimes becomes electrified and the diatoms will not stick; on sultry
+days in August in our locality the diatoms will stick too closely.
+
+By the same method, slides of arranged diatoms can be made using a glass
+circle properly marked with lines in the eye-piece. Care should be taken to
+use glass threads more or less in proportion to the size of the diatoms. A
+cat's whisker is preferred by some to the glass thread. It has the
+advantage of not breaking, but unless it is quite short it is too flexible.
+If the point of the thread becomes covered with gelatine, lower it into a
+minute drop of water upon a separate slide, and by moving it about it will
+be cleaned. The diatom itself may be washed in the same way, if it is not
+too small.
+
+_Instruments Required._--For collecting, in order to determine the quality
+of the find, any simple lens of fifteen to twenty diameters is sufficient.
+A Stanhope is quite useful {135}although difficult to obtain, while an
+achromatic triplet of sufficient power will probably be all that is
+necessary. For selecting with the mechanical finger, an objective of
+two-thirds-inch focus is the most convenient, but for determining species a
+one-fifth-inch is needed, an immersion objective being essential for minute
+forms.
+
+No particular form of microscope is required. Any instrument having
+standard parts, inclination of the body to the axis, a sub-stage condenser
+and movable stage, will prove serviceable in nearly all investigations. For
+critical work, measurement of striæ and location of specimens on the slide,
+the large models of Bausch and Lomb leave nothing to be desired. One
+smaller instrument may be used for rapid examination and for selection with
+the mechanical finger. If the stage is supplied with a vernier, the diatoms
+can be located rapidly and recorded for future reference. The Zentmayer
+Army Hospital stand with mechanical stage is excellent. The Continental
+stands, convenient for laboratory work, especially in the examination of
+bacteria, are not so serviceable as the larger stands of American and
+English make. The stand especially designed by Dr. Henri Van Heurck, the
+celebrated Belgian naturalist, is, without doubt, admirably suited to the
+investigation of the Diatomaceæ. In the form of the Circuit Stage as made
+by Watson and Sons, of London, supplied with proper condenser and
+mechanical stage with vernier attachment, it has been used in the
+preparation of the present work with much satisfaction.
+
+The drawings have all been made with an Abbé camera lucida, a 3 mm.
+objective and a No. 10 eye-piece, producing a magnification of about 800
+diameters. All illustrations are from actual specimens in my cabinet or, in
+a few instances, from slides sent me by friends. In the measurement of
+striæ and puncta, the number in ten microns is stated, and will be found to
+be approximately correct in most of the drawings, except when the number is
+in excess of twenty in ten microns, in which case it is impossible to
+represent the markings accurately on figures of the magnification adopted.
+All drawings are from specimens in this locality, except in a few cases
+mentioned in the text.
+
+
+
+
+{137}INDEX
+
+
+(SYNONYMS IN ITALICS)
+
+
+
+                                                PAGE
+  Achnanthes,                                     58
+    brevipes Ag.,                                 59
+    coarctata (Bréb.) Grun.,                      59
+    danica (Floegel) Grun.,                       60
+    exigua Grun.,                                 59
+    inflata (Kuetz.) Grun.,                       59
+    lanceolata (Bréb.) Grun.,                     59
+    linearis forma curta H.L.S.,                  59
+    longipes Ag.,                                 58
+    subsessilis Kuetz.,                           59
+
+  Actinella,                                      54
+    punctata Lewis,                               54
+
+  Actinocyclus,                                   26
+    barkleyi var. aggregata Rattr.,               27
+    ellipticus var. delawarensis n. var.,         27
+    moniliformis Ralfs,                           27
+
+  Actinoptychus,                                  24
+    _cellulosa_ Ehr.,                             24
+    heliopelta Grun. var.?,                       25
+    _omphalopelta_ Ehr.,                          24
+    undulatus (Kuetz.) Ralfs,                     24
+    vulgaris var. interrupta n. var.,             24
+
+  Amphipleura,                                    78
+    pellucida Kuetz.,                             78
+    rutilans (Trentepohl) Cl.,                    78
+
+  Amphiprora,                                     68
+    alata Kuetz.,                                 68
+    conspicua Grev.,                              68
+    _lepidoptera_ Greg.,                          69
+    ornata Bail.,                                 68
+    paludosa Wm. Sm.,                             68
+    pulchra Bail.,                                68
+
+  _Amphitetras_,
+    _antediluviana_ Ehr.,                         32
+    _tessellata_ Shad.,                           32
+
+  Amphora,                                        65
+    acuta Greg.,                                  66
+    angusta var. eulensteinii Grun.,              67
+    _aponina_ Kuetz.,                             66
+    arenaria Donk.,                               67
+    areolata Grun.,                               66
+    coffæiformis (Ag.) Kuetz.,                    66
+    crassa Greg.,                                 65
+    _eulensteinii_ A.S.,                          67
+    gigantea var. fusca A.S.,                     65
+    _insecta_ Grun.,                              69
+    lævis Greg.,                                  66
+    lineolata Ehr.,                               66
+    _mucronata_ H.L.S.,                           69
+    obtusa Greg.,                                 67
+    ocellata var. cingulata Cl.,                  67
+    ostrearia Bréb.,                              66
+    ovalis (Bréb.) Kuetz.,                        65
+      var. libyca (Ehr.) Cl.,                     65
+      var. pediculus (Kuetz.) Cl.,                65
+    _plicata_ Greg.,                              66
+    _porcellus_ Kitton,                           66
+    proteus Greg.,                                65
+    _quadrata_ Bréb.,                             66
+    robusta Greg.,                                65
+    _salina_ Wm. Sm.,                             66
+    _vitræa_ Cl.,                                 66
+
+  Anomoeoneis,                                    80
+    follis (Ehr.) Cl.,                            80
+    serians Bréb.,                                80
+    sphærophora (Kuetz.) Cl.,                     80
+
+  Anorthoneis,                                    56
+    excentrica (Donk.) Grun.,                     56
+
+  Asterionella,                                   50
+    formosa Hass.,                                50
+    inflata Heib.,                                50
+
+  Attheya,                                        38
+    decora West,                                  38
+
+  Aulacodiscus,                                   26
+    argus (Ehr.) A.S.,                            26
+
+  Auliscus,                                       28
+    cælatus Bail.,                                29
+    pruinosus Bail.,                              28
+    punctatus Bail.,                              28
+    sculptus (Wm. Sm.) Ralfs,                     29
+    _spinosus_ Christian,                         29
+
+  Auricula,                                       69
+    _insecta_ (Grun.) Cl.,                        69
+    mucronata (H.L.S.) Per.,                      69
+
+  _Bacillaria_,                                  119
+    _paradoxa_ Gmelin,                           119
+
+  Biddulphia,                                     31
+    alternans (Bail.) V. H.,                      33
+    antediluviana (Ehr.) V. H.,                   32
+    biddulphiana (Smith),                         31
+    favus (Ehr.) V. H.,                           31
+    granulata Roper,                              32
+    lævis Ehr.,                                   33
+    _pulchella_ Gray.,                            31
+    reticulum (Ehr.),                             33
+    rhombus (Ehr.) Wm. Sm.,                       32
+    smithii (Ralfs) V. H.,                        32
+    turgida (Ehr.) Wm. Sm.,                       32
+
+  Brébissonia,                                    79
+    boeckii (Kuetz.) Grun.,                       79
+    palmerii n. sp.,                              80
+
+  Caloneis,                                       81
+    brevis var. vexans Grun.,                     82
+    formosa (Greg.) Cl.,                          82
+    liber (Wm. Sm.) Cl.,                          81
+    permagna (Bail.) Cl.,                         82
+      var. lewisiana n. var.,                     82
+    powellii (Lewis) Cl.,                         83
+    silicula (Ehr.) Cl.,                          81
+      var. inflata (Grun.) Cl.,                   81
+    trinodis (Lewis),                             81
+    wardii Cl.,                                   82
+
+  Campylodiscus,                                 129
+    _argus_ Bail.,                               130
+    echeneis Ehr.,                               130
+    hibernicus Ehr.,                             130
+
+  _Cerataulus_
+    _smithii_ Ralfs,                              32
+    _turgidus_ Ehr.,                              32
+
+  Cocconeis,                                      57
+    dirupta Greg.,                                58
+    pediculus Ehr.,                               57
+    pellucida Grun.,                              58
+    placentula Ehr.,                              57
+      var. lineata (Ehr.) V. H.,                  58
+    scutellum Ehr.,                               57
+      var. ornata Grun.,                          57
+
+  _Cocconema_
+    _asperum_ Ehr.,                               61
+
+  _Colletonema_
+    _neglectum_ Thwaites,                         95
+    _vulgaris_ Thwaites,                          77
+
+  _Conferva_
+    _biddulphiana_ Smith,                         31
+    _flocculosa_ Roth,                            36
+    _moniliformis_ Mueller,                       16
+    _nummuloides_ Dillw.,                       1617
+    _rutilans_ Trentepohl,                        78
+
+  Coscinodiscus,                                  21
+    argus Ehr.,                                   23
+    asteromphalus Ehr.,                           23
+      var. omphalantha Grun.,                     23
+    biangulatus A. S.,                            23
+    denarius A. S.,                               22
+    excentricus Ehr.,                             21
+      var. perpusilla Grun.,                      21
+    lewisianus Grev.,                             24
+    lineatus Ehr.,                                21
+    marginatus Ehr.,                              22
+    _minor_ Wm. Sm.,                              14
+    nitidulus Grun.,                              21
+    nitidus Greg.,                                21
+    oculus-iridus Ehr.,                           23
+    polyacanthus Grun.,                           22
+    radiatus Ehr.,                                23
+    _striatus_ Kuetz.,                            19
+    subaulacodiscoidalis Rattr.,                  23
+    subtilis Ehr.,                                21
+    velatus Ehr.,                                 22
+
+  _Creswellia_
+    _turris_ Grev.,                               18
+
+  Cyclotella,                                     19
+    antiqua Wm. Sm.,                              20
+    comta (Ehr.) Kuetz.,                          20
+    _dallasiana_ Wm. Sm.,                         19
+    _kuetzingiana_ Wm. Sm.,                       19
+    meneghiniana Kuetz.,                          19
+      var. stelligera Cl. and Grun.,              20
+      var. stellulifera Cl. and Grun.,            20
+    operculata (Ag.) Kuetz.,                      20
+    _scotica_ Kuetz.,                             18
+    striata (Kuetz.) Grun.,                       19
+    stylorum (Br.?) V. H.,                        20
+
+  Cymatopleura,                                  129
+    elliptica (Bréb.) Wm. Sm.,                   129
+    marina Lewis,                                129
+    solea (Bréb.) Wm. Sm.,                       129
+
+  Cymbella,                                       60
+    affinis Kuetz.,                               61
+    amphicephala Nægeli,                          61
+    aspera (Ehr.) Cl.,                            61
+    cistula (Hempr.) Kirchn.,                     62
+    cuspidata Kuetz.,                             60
+    cymbiformis (Kuetz.) Bréb.,                   62
+    ehrenbergii Kuetz.,                           60
+    excisa (Kuetz.) De Toni,                      61
+    _gastroides_ Kuetz.,                          61
+    gracilis (Rab.) Cl.,                          64
+    heteropleura (Ehr.) Kuetz.,                   60
+    lacustris (Ag.) Cl.,                          64
+    lanceolata (Ehr.) Kirchn.,                    62
+    mexicana (Ehr.) A. S.,                        62
+    naviculiformis Auerswald,                     60
+    parva (Wm. Sm.) Cl.,                          61
+    philadelphica n. sp.,                         63
+    prostrata (Berk.) Cl.,                        63
+    rhomboidea n. sp.,                            63
+    sinuata Greg.,                                61
+    triangulum (Ehr.) Cl.,                        63
+    tumida (Bréb.) V. H.,                         62
+    turgida (Greg.) Cl.,                          63
+      var.?,                                      63
+    ventricosa Kuetz.,                            62
+
+  Diatoma,                                        41
+    anceps (Ehr.) Kirchn.,                        42
+    _arcuatum_ Lyng.,                             35
+    _biddulphianum_ Ag.,                          31
+    hiemale (Lyng.) Heib.,                        42
+    _marinum_ Lyng.,                              37
+    vulgare Bory.,                                42
+      var. elongatum (Ag.),                       42
+      var. grande (Wm. Sm.) Grun.,                42
+
+  Dictyoneis,                                     78
+    marginata var. commutata Cl.,                 79
+      var. maxima n. var.,                        79
+      var. typica Cl.,                            78
+
+  Dimerogramma,                                   46
+    marinum (Greg.) Ralfs,                        46
+    minus (Greg.) Ralfs,                          47
+    _sinuatum_ Thwaites,                         119
+    surirella (Ehr.) Grun.,                       46
+
+  Diploneis,                                      84
+    campylodiscus (Grun.) Cl.,                    86
+    crabro Ehr. var.?,                            85
+      var. expleta (A. S.) Cl.,                   85
+      var. pandura (Bréb.) Cl.,                   85
+      var. pandurella Cl.?,                       85
+    elliptica (Kuetz.) Cl.,                       84
+      var. _minutissima_ Grun.,                   85
+    excentrica n. sp.,                            85
+    fusca var. delicata (A. S.) Cl.,              85
+    gemmata (Grev.) Cl.,                          86
+    gruendleri (A. S.) Cl.,                       85
+    oculata (Bréb.) Cl.,                          86
+    puella (Schum.) Cl.,                          85
+    smithii (Bréb.) Cl.,                          84
+
+  Ditylum,                                        30
+    intricatum (West) Grun.,                      30
+
+  _Echinella_
+    _circularis_ Grev.,                           40
+    _flabellata_ Carm.,                           39
+    _paradoxa_ Lyng.,                             39
+
+  Encyonema,                                      62
+
+  Epithemia,                                     111
+    argus Kuetz.,                                111
+      var.?,                                     111
+    _gibba_ var. _ventricosa_ Kuetz.,            113
+    gibberula var. producta Grun.,               112
+    _marina_ Donk.,                              114
+    muelleri A. S.?,                             111
+    musculus Kuetz.,                             112
+      var. constricta (Bréb.) V. H.,             112
+    _succincta_ Bréb.,                           112
+    turgida (Ehr.) Kuetz.,                       111
+    zebra var. proboscidea (Kuetz.) Grun.,       112
+
+  Eunotia,                                        51
+    bactriana Ehr.,                               54
+    biceps Ehr.,                                  53
+    bidentula Wm. Sm.,                            54
+    _bigibba_ Greg.,                              53
+    formica Ehr. var.?,                           54
+    gracilis (Ehr.) Rab.,                         51
+    hemicyclus (Ehr.) Ralfs,                      53
+    _incisa_ Greg.,                               52
+    luna Ehr.,                                    52
+    lunaris (Ehr.) Grun.,                         53
+    major (Wm. Sm.) Rab.,                         51
+    nymanniana Grun.,                             51
+    pectinalis (Kuetz.),                          52
+      var. solierolii (Kuetz.),                   52
+      var. undulata Ralfs,                        52
+      var. ventricosa Grun.,                      52
+    prærupta Ehr.,                                53
+      var. bidens Grun.,                          53
+    robusta Ralfs,                                53
+    veneris Kuetz.,                               52
+
+  Eunotogramma,                                   33
+    læve Grun.,                                   33
+
+  Euodia,                                         34
+    gibba Bail.,                                  34
+
+  Eupodiscus,                                     28
+    _argus_ (Ehr.) Wm. Sm.,                       26
+    radiatus Bail.,                               28
+    _radiatus_ Wm. Sm.,                           32
+
+  Fragilaria,                                     44
+    arctica Grun.,                                44
+    capucina var. mesolepta Rab.,                 45
+    construens (Ehr.) Grun.,                      45
+    harrisonii (Wm. Sm.) Grun.,                   45
+    linearis Cstr.,                               45
+    parasitica (Wm. Sm.),                         45
+    undata Wm. Sm.,                               44
+    virescens Ralfs,                              44
+
+  Frustulia,                                      77
+    _acuminata_ Kuetz.,                           76
+    interposita (Lewis) De Toni,                  78
+    lewisiana (Grev.) De Toni,                    77
+    rhomboides (Ehr.) De Toni,                    77
+      var. amphipleuroides Grun.,                 77
+      var. saxonica Rab.,                         77
+    vulgaris (Thwaites) De Toni,                  77
+
+  Gaillonella,                                    16
+    _crenulata_ Ehr.,                             15
+    _granulata_ Ehr.,                             15
+    _moniliformis_ Bail.,                         16
+    nummuloides (Dillw.) Bory.,                   16
+    _sulcata_ Ehr.,                               15
+
+  _Gloeonema_,                                    63
+    _triangulum_ Ehr.,                            63
+
+  Gomphoneis,                                     70
+    herculaneum (Ehr.) Cl.,                       70
+    mamilla (Ehr.) Cl.,                           70
+
+  Gomphonema,                                     70
+    acuminatum,                                   71
+      var. coronata (Ehr.) Cl.,                   71
+      var. trigonocephala (Ehr.) Cl.,             71
+      var. turris (Ehr.) Cl.,                     71
+      var. turris (Ehr.) Cl.?,                    71
+    æquale Greg.,                                 72
+    angustatum Kuetz.,                            72
+    augur Ehr.,                                   72
+    brasiliense var. demeraræ Grun.?,             73
+    capitatum Ehr.,                               72
+    capitatum var. herculaneum Ehr.,              70
+    constrictum Ehr.,                             72
+    geminatum Lyng.,                              71
+    _insigne_ Greg.,                              71
+    intricatum Kuetz.,                            72
+    lanceolatum var. insignis (Greg.) Cl.,        71
+    montanum Schum.,                              71
+    olivaceum Lyng.,                              73
+    parvulum var. micropus (Kuetz.) Cl.,          73
+    sarcophagus Greg.,                            72
+    sphærophorum Ehr.,                            72
+    _subclavatum_ var. _montana_ Schum.,          71
+    _tinctum_ Ag.,                                40
+    ventricosum Greg.,                            73
+
+  Grammatophora,                                  36
+    angulosa var. hamulifera (Kuetz.) Grun.,      37
+    islandica Ehr.,                               37
+    marina (Lyng.) Kuetz.,                        37
+      var. subtilissima (Bail.) V. H.,            37
+    serpentina Ralfs,                             37
+    _subtilissima_ Bail.,                         37
+
+  Gyrosigma,                                      75
+    acuminatum (Kuetz.) Cl.,                      76
+    _attenuatum_ (Kuetz.) Cl.,                    75
+    balticum (Ehr.) Cl.,                          75
+      var. _similis_ (Grun.) Cl.,                 76
+    fasciola (Ehr.) Cl.,                          77
+    hippocampus (Ehr.),                           75
+    kuetzingii (Grun.) Cl.,                       76
+    parkeri var. stauroneioides Grun.,            75
+    prolongatum (Wm. Sm.) Cl.,                    76
+    scalproides (Rab.) Cl.,                       76
+    simile (Grun.),                               76
+    spencerii var. nodifera Grun.,                76
+    strigilis (Wm. Sm.) Cl.,                      76
+
+  Hantzschia,                                    113
+    amphioxys (Ehr.) Grun.,                      113
+      var. major Grun.,                          114
+    marina (Donk.) Grun.,                        114
+    virgata (Roper) Grun.,                       114
+
+  _Himantidium_
+    _pectinate_ Kuetz.,                           52
+
+  Homoeocladia,                                  123
+    filiformis Wm. Sm.,                          123
+
+  Hyalodiscus,                                    17
+    radiatus var. arctica Grun.,                  17
+    scoticus (Kuetz.) Grun.,                      18
+    stelliger Bail.,                              17
+    subtilis Bail.,                               18
+
+  Licmophora,                                     38
+    baileyi (Ehr.) Grun.,                         40
+    ehrenbergii (Kuetz.) Grun.,                   40
+    flabellata (Carm.) Ag.,                       39
+    gracilis (Ehr.) Grun.,                        39
+      var. elongata (Kuetz.) De Toni,             39
+    lyngbyei (Kuetz.) Grun.,                      40
+    ovulum Mer.,                                  39
+    paradoxa (Lyng.) Ag.,                         39
+    _splendida_ Wm. Sm.,                          39
+    tincta (Ag.) Grun.,                           40
+
+  Lysigonium,                                     16
+    moniliforme (Muell.) Link,                    16
+    _nummuloides_ (Lyng.) O'Meara,                17
+    varians (Ag.) De Toni,                        17
+
+  Mastogloia,                                     86
+    angulata Lewis,                               87
+    apiculata Wm. Sm.,                            87
+    _braunii_ Grun.,                              87
+    elegans Lewis,                                87
+    exigua Lewis,                                 87
+    kinsmanii Lewis,                              87
+    lanceolata Thwaites,                          87
+    smithii Thwaites,                             87
+
+  Meloseira,                                      14
+    _borreri_ Grev.,                              17
+    crenulata (Ehr.) Kuetz.,                      15
+    distans (Ehr.) Kuetz.,                        14
+    _gowenii_ A. S.,                              15
+    granulata (Ehr.) Ralfs,                       15
+    _nivalis_ Wm. Sm.,                            14
+    _nummuloides_ Ag.,                            16
+    roeseana Rab.,                                15
+      var. epidendron (Ehr.) Grun.,               15
+    sulcata Kuetz.,                               15
+    undulata (Ehr.) Kuetz.,                       15
+    _varians_ Ag.,                                17
+
+  Meridion,                                       40
+    circulare (Grev.) Ag.,                        40
+    _constrictum_ Ralfs,                          41
+
+  _Micromega_
+    _ramosissimum_ Ag.,                           95
+
+  Navicula,                                       89
+    _affinis_ Ehr.,                               83
+    americana Ehr.,                               98
+    _amphibola_ Cl.,                              92
+    _amphigomphus_ Ehr.,                          83
+    anglica Ralfs,                                96
+    _angulata_ Quek.,                             74
+    ardua Mann,                                   96
+    _arenaria_ Donk.,                             95
+    atomus Nægeli,                               100
+    bacillum Ehr.,                                98
+    _baltica_ Ehr.,                               75
+    brasiliensis var. bicuneata Cl., forma
+      constricta,                                 92
+    crucigera (Wm. Sm.) Cl.,                     100
+    cryptocephala Kuetz.,                         97
+    cuspidata Kuetz.,                            100
+      var. ambigua (Ehr.) Cl.,                   100
+    cyprinus (Wm. Sm.),                           95
+    delawarensis Grun.,                           92
+    dicephala Wm. Sm.,                            96
+    _digito-radiata_ var. _cyprinus_ (Ehr.?) Wm.
+      Sm.,                                        95
+    elegans Wm. Sm.,                             101
+      var. cuspidata Cl.,                        101
+    _firma_ Kuetz.,                               84
+    _fischeri_ A. S.,                             90
+    _follis_ Ehr.,                                80
+    fuchsii Pant.,                                91
+    gastrum Ehr.,                                 96
+    _gigas_ A. S.,                               103
+    _globiceps_ Lagerstedt,                       96
+    gracilis var. schizonemoides (Ehr.) V. H.,    95
+    grevillei (Ag.) Cl.,                          99
+    hasta Pant.,                                  97
+      var. punctata n. var.,                      97
+    hennedyi Wm. Sm.,                             93
+      var. circumsecta Grun.,                     93
+      var. manta A. S.,                           93
+    _hippocampus_ Ehr.,                           75
+    _hitchcockii_ Ehr.,                           84
+    humerosa Bréb.,                               91
+      var. _elongata_ Pant.,                      91
+      var. _fuchsii_ (Pant.) Cl.,                 91
+    humilis Donk.,                                96
+    _hungarica_ var. _capitata_ (Ehr.) Cl.,       96
+    inflexa Greg.,                                96
+    integra Wm. Sm.,                              99
+    _interposita_ Lewis,                          78
+    _iridis_ Ehr.,                                84
+    irrorata Grev.,                               93
+    lacustris Greg.,                              92
+    lanceolata var. arenaria (Donk.) Cl.,         95
+    latissima Greg.,                              90
+      var. elongata (Pant.) Cl.,                  91
+    libellus Greg.,                               99
+    _limosa_ Donk.,                               81
+    longa (Greg.) Ralfs,                          97
+    lyra Ehr.,                                    93
+      var. dilatata A. S.,                        93
+      var. ehrenbergii Cl.,                       93
+      var.?,                                      93
+    maculata (Bail.) Cl.,                         90
+    _marginata_ Lewis,                            78
+    _marina_ Ralfs,                               92
+    minima Grun.,                                 98
+    _mormonorum_ Grun.,                          107
+    mutica Kuetz.,                                97
+    oblonga Kuetz.,                               97
+    _oculata_ Bréb.,                              86
+    palpebralis Bréb.,                           101
+    pennata A. S.,                                96
+    peregrina Ehr.,                               94
+    pinnata Pant.?,                               96
+    placenta Ehr.,                                94
+    prætexta Ehr.,                                92
+    _producta_ Wm. Sm.,                           83
+    punctata var. asymmetrica Lagerstedt,         92
+    punctulata Wm. Sm.,                           92
+    pupula var. bacillarioides Grun.,             98
+    pusilla Wm. Sm.,                              91
+      var. subcapitata n. var.,                   91
+    pygmæa Kuetz.,                                94
+    radiosa Kuetz.,                               94
+    ramosissima (Ag.) Cl.,                        95
+    _rectangulata_ Greg.,                        110
+    reinhardtii Grun.,                            95
+    rhyncocephala Kuetz.,                         97
+    salinarum Grun.,                              95
+    semen Ehr.,                                   98
+    _silicula_ Ehr.,                              81
+    _socialis_ Palmer,                           104
+    spectabilis var. emarginata Cl.,              94
+    _sphærophora_ Kuetz.,                         80
+    spicula (Hickie) Cl.,                        100
+    _trochus_ Kuetz.,                             80
+    tumida (Bréb.) Cl.,                           99
+    viridula var. rostellata Kuetz.,              95
+    yarrensis Grun.,                             101
+
+  Neidium,                                        83
+    affine (Ehr.) Pfitzer,                        83
+      var. amphirhyncus (Ehr.) Cl.,               83
+      var. genuina forma maxima Cl.,              83
+      var. genuina forma minor Cl.,               83
+    amphigomphus (Ehr.) Pfitzer,                  83
+    hitchcockii (Ehr.) Cl.,                       84
+    iridis (Ehr.) Cl.,                            84
+    productum (Wm. Sm.) Cl.,                      83
+
+  Nitzschia,                                     114
+    acicularis (Kuetz.) Wm. Sm.,                 123
+    acuminata (Wm. Sm.) Grun.,                   117
+    amphibis Grun.,                              122
+    amphioxys Wm. Sm.,                           114
+    apiculata (Greg.) Grun.,                     117
+    bilobata Wm. Sm.,                            118
+    circumsuta (Bail.) Grun.,                    118
+    clausii Hantzsch,                            121
+    communis Rab.,                               122
+    compressa Bail.,                             116
+      var. minor H. L. S.,                       116
+    _curvula_ Wm. Sm.,                           121
+    dissipata (Kuetz.) Grun.,                    120
+    dubia Wm. Sm.,                               118
+    epithemioides Grun.,                         118
+    fluminensis Grun.,                           120
+    granulata Grun.,                             116
+    insignis Greg.,                              119
+    intermedia Hantzsch,                         122
+    linearis (Ag.) Wm. Sm.,                      122
+    litoralis var. delawarensis Grun.,           118
+    longissima (Bréb.) Ralfs,                    123
+      forma parva V. H.,                         123
+    macilenta Greg.,                             120
+    navicularis (Bréb.) Grun.,                   116
+    obtusa Wm. Sm.,                              121
+      var. flexella H. L. S.,                    121
+      var. scalpelliformis Grun.,                121
+    palea (Kuetz.) Wm. Sm.,                      122
+    panduriformis Greg.,                         117
+      var. minor Grun.,                          117
+    _paradoxa_ (Gmelin) Grun.,                   119
+    paxillifer (O. F. Mueller) Heib.,            119
+    plana Wm. Sm.,                               117
+    _punctata_ (Wm. Sm.) Grun.,                  116
+    reversa Wm. Sm.,                             123
+    scalaris (Ehr.) Wm. Sm.,                     119
+    sigma (Kuetz.) Wm. Sm.,                      121
+      var. _curvula_ (Wm. Sm.) De Toni,          121
+    sigmatella Greg.,                            121
+    _sinuata_ var. _tabellaria_ (Grun.) V. H.,   119
+    spathulata Bréb.,                            120
+    spectabilis var. americana Grun.,            122
+    tabellaria Grun.,                            119
+    tryblionella Hantzsch,                       116
+    vermicularis (Kuetz.) Hantzsch,              120
+
+  _Odontidium_
+    _parasiticum_ Wm. Sm.,                        45
+    _tabellaria_ Wm. Sm.,                         45
+
+  Opephora,                                       43
+    pacifica (Grun.) Petit,                       43
+    pinnata var. lanceolata n. var.,              44
+    schwartzii (Grun.) Petit,                     43
+
+  _Orthosira_
+    _orichalcea_ Wm. Sm.,                         15
+    _punctata_ Wm. Sm.,                           15
+    _spinosa_ Grev.,                              15
+
+  _Paralia_
+    _marina_ Heib.,                               15
+    _sulcata_ (Ehr.) Cl.,                         15
+
+  Pinnularia,                                    101
+    acrosphæria (Bréb.) Cl.,                     108
+      var. turgidula Grun.?,                     108
+    æstuarii Cl.,                                105
+    appendiculata (Ag.) Cl.,                     106
+    blandita n. sp.,                             108
+    borealis Ehr.,                               109
+      var. scalaris (Ehr.) Cl.,                  109
+    braunii Grun.,                               106
+    brébissonii (Kuetz.) Cl.,                    107
+    cardinaliculus Cl.,                          107
+    _cyprinus_ Wm. Sm.,                           95
+    dactylus Ehr.,                               103
+      var. dariana (A. S.) Cl.,                  103
+      var. demeraræ Cl.,                         103
+    divergens var. elliptica Grun.,              107
+    gentilis (Donk.) Cl.,                        103
+    gibba (Kuetz.) V. H.,                        109
+    _interrupta_ forma _stauroneiformis_ Cl.,    106
+    lata (Bréb.) Wm. Sm.,                        109
+    legumen Ehr.,                                107
+      var.?,                                     107
+    leptosoma Grun.,                             105
+    major (Kuetz.) Wm. Sm.,                      102
+      var. pulchella n. var.,                    102
+    mesogongyla (Ehr.) Cl.,                      109
+    mesolepta Ehr.,                              105
+      var. stauroneiformis Grun.,                105
+    microstauron (Ehr.) Cl.,                     106
+    molaris (Grun.) Cl.,                         105
+    mormonorum Grun.,                            107
+    nobilis Ehr.,                                103
+    nodosa forma capitata Cl.,                   108
+    parva (Ehr.) Cl.,                            108
+    _permagna_ Bail.,                             82
+    polyonca (Bréb.) Lewis,                      108
+    rectangulata (Greg.) Cl.,                    110
+    socialis (Palmer),                           104
+    stauroptera (Grun.) Cl.,                     110
+      var. interrupta forma stauroneiformis Cl., 110
+    stomatophora (Grun.) Cl.,                    109
+    subcapitata Greg.,                           105
+      var. paucistriata Grun.,                   106
+    tabellaria (Ehr.) Cl.,                       110
+    termes (Ehr.) A. S.,                         106
+      var. stauroneiformis V. H.,                106
+    trigonocephala Cl.,                          103
+    viridis Nitzsch,                             104
+      var. caudata n. var.,                      104
+      var. fallax Cl.,                           104
+      var.?,                                     104
+
+  Plagiogramma,                                   42
+    obesum Grev.,                                 43
+    pygmæum Grev.,                                43
+    tessellatum Grev.,                            43
+    wallichianum Grev.,                           43
+
+  Pleurosigma,                                    73
+    æstuarii Bréb.,                               74
+    _affine_ var. _fossilis_ Grun.,               74
+    angulatum (Quekett) Cl.,                      74
+    _balticum_ (Ehr.) Wm. Sm.,                    75
+    formosum Wm. Sm.,                             73
+    _hippocampus_ (Ehr.) Wm. Sm.,                 75
+    naviculaceum Bréb.,                           74
+    _normanii_ var. _fossilis_ Grun.,             74
+    obscurum Wm. Sm.,                             74
+    rigidum Wm. Sm.,                              75
+    _simile_ Grun.,                               76
+    _spencerii_ var. _acutiuscula_ Grun.,         76
+      var. _kuetzingii_ Grun.,                    76
+    strigosum Wm. Sm.,                            74
+    virginiacum H. L. S.,                         74
+
+  Podocystis,                                    128
+    adriatica Kuetz.,                            129
+    _americana_ Bail.,                           129
+
+  _Podosira_
+    _hormoides_ Wm. Sm.,                          18
+    _maculata_ Wm. Sm.,                           17
+
+  _Podosphenia_
+    _baileyi_ (Edw.) Lewis,                       40
+    _ehrenbergii_ Kuetz.,                         40
+    _lyngbyei_ Kuetz.,                            40
+
+  Polymyxus,                                      25
+    coronalis L. W. Bail.,                        25
+
+  Pseudauliscus,                                  29
+    radiatus (Bail.) Rattr.,                      29
+    spinosus (Christian) Rattr.,                  29
+
+  Pyxidicula,                                     19
+    _compressa_ Bail.,                           116
+      var. _minor_ H. L. S.,                     116
+    cruciata Ehr.,                                19
+    _radiata_ O'Meara,                            17
+
+  Rhabdonema,                                     35
+    adriaticum Kuetz.,                            36
+    arcuatum (Lyng.) Kuetz.,                      35
+    minutum Kuetz.,                               36
+
+  Rhaphoneis,                                     46
+    amphiceros Ehr.,                              46
+      var. rhombica Grun.,                        46
+    belgica var. intermedia Grun.,                46
+
+  _Rhipidophora_
+    _elongata_ Kuetz.,                            39
+    _paradoxa_ Kuetz.,                            39
+
+  Rhoicosphenia,                                  56
+    curvata (Kuetz.) Grun.,                       56
+
+  Rhopalodia,                                    112
+    gibba (Kuetz.) Mueller,                      112
+    ventricosa (Kuetz.) Mueller,                 113
+
+  _Schizonema_
+    _cruciger_ Wm. Sm.,                          100
+    _dillwynii_ Wm. Sm.,                          78
+    _grevillei_ Ag.,                              99
+    _smithii_ Kuetz.,                             95
+
+  _Scoliopleura_
+    _tumida_ (Bréb.) V. H.,                       99
+
+  Scoliotropis,                                   69
+    latestriata var. amphora Cl.,                 69
+
+  Stauroneis,                                     88
+    acuta Wm. Sm.,                                89
+    americana A. S.,                              89
+    anceps Ehr.,                                  88
+      var. amphicephala (Kuetz.) Cl.,             88
+      var. gracilis (Ehr.) Cl.,                   88
+    crucicula (Grun.) Cl.,                        89
+    _exilis_ Kuetz.,                              59
+    frickei var. angusta n. var.,                 88
+    legumen Ehr.,                                 89
+    _maculata_ Bail.,                             90
+    phoenicenteron Ehr.,                          88
+    salina Wm. Sm.,                               89
+    smithii Grun.,                                89
+    _spicula_ Hickie,                            100
+
+  _Staurosira_
+    _construens_ Ehr.,                            45
+
+  Stephanopyxis,                                  18
+    _appendiculata_ Ehr.,                         18
+    corona (Ehr.) Grun.,                          18
+    turris (Grev.) Ralfs,                         18
+
+  Striatella,                                     37
+    interrupta (Ehr.) Heib.,                      38
+    unipunctata (Lyng.) Ag.,                      38
+
+  Surirella,                                     124
+    amphioxys Wm. Sm.,                           124
+    anceps Lewis,                                128
+    angusta Kuetz.,                              127
+    arctissima A. S.,                            128
+    _bifrons_ Ehr.,                              124
+    biseriata (Ehr.) Bréb.,                      124
+    _cardinalis_ Kitton,                         126
+    _circumsuta_ Bail.,                          118
+    cruciata A. S.,                              127
+    crumena Bréb.,                               126
+    _davidsonii_ A. S.,                          126
+    delicatissima Lewis,                         128
+    _diaphana_ Bleisch,                          125
+    elegans Ehr.,                                125
+    fastuosa Ehr.,                               127
+    febigerii Lewis,                             128
+    gemma Ehr.,                                  125
+    gracilis Grun.,                              127
+    guatimalensis Ehr.,                          126
+    intermedia Lewis,                            128
+    linearis Wm. Sm.,                            124
+    _moelleriana_ Grun.,                         124
+    oblonga Ehr.?,                               127
+    ovalis Bréb.,                                126
+      var. _pinnata_ (Wm. Sm.) De Toni,          126
+    panduriformis Wm. Sm.,                       126
+    pinnata Wm. Sm.,                             126
+      var. minuta Grun.,                         126
+    recedens A. S.,                              127
+    robusta Ehr.,                                124
+    splendida (Ehr.) Kuetz.,                     125
+    striatula Turpin,                            125
+    tenera Greg.,                                125
+
+  Synedra,                                        47
+    acus Kuetz.,                                  48
+    affinis Kuetz.,                               50
+      var. parva (Kuetz.) V. H.,                  50
+      var. tabulata (Ag.) V. H.,                  50
+    biceps (Kuetz.) A. S.,                        48
+    capitata Ehr.,                                48
+    danica Kuetz.,                                48
+    fulgens (Grev.) Wm. Sm.,                      50
+    goulardi Bréb.,                               48
+    _gracilis_ Kuetz.,                            50
+    oxyrhynchus var. undulata Grun.,              48
+    pulchella (Ralfs) Kuetz.,                     48
+      var. abnormis Macchiati?,                   48
+      var. flexella n. var.,                      49
+    radians Kuetz.,                               49
+    ulna (Nitzsch) Ehr.,                          47
+    vaucheriæ var. parvula (Kuetz.) Rab.,         49
+
+  Tabellaria,                                     36
+    fenestrata (Lyng.),                           36
+    flocculosa (Roth) Kuetz.,                     36
+
+  Terpsinoë,                                      34
+    americana (Bail.) Ralfs,                      34
+    novæ-cæsareæ Boyer,                           34
+
+  _Tessella_
+    _interrupta_ Ehr.,                            38
+
+  Trachyneis,                                     79
+    aspera var. intermedia Grun.,                 79
+
+  Trachysphenia,                                  47
+    australis Petit,                              47
+
+  _Triceratium_
+    _alternans_ Bail.,                            33
+    _favus_ Ehr.,                                 31
+    _obtusum_ Br.,                                33
+    _pileotus_ Ehr.,                              30
+    _punctatum_ Br.,                              33
+    _sculptum_ Shad.,                             33
+
+  Trinacria,                                      30
+    pileolus (Ehr.) Grun.,                        30
+
+  _Tripodiscus_
+    _argus_ Ehr.,                                 26
+
+  Tropidoneis,                                    68
+    lepidoptera (Greg.) Cl.,                      69
+
+  _Tryblionella_
+    _punctata_ Wm. Sm.,                          116
+    _scutellum_ Wm. Sm.,                         118
+
+  _Vibrio_
+    _paxillifer_ O. F. Mueller,                  119
+
+
+
+
+PLATES
+
+
+PLATE 1
+
+
+
+  MELOSEIRA
+
+  3-4            Meloseira roeseana var. epidendron (Ehr.) Grun.         15
+
+  5-6            Meloseira roeseana Rab.                                 15
+
+  8-9            Meloseira distans (Ehr.) Kuetz.                         14
+
+  10             Meloseira granulata (Ehr.) Ralfs                        15
+
+  11-12          Meloseira sulcata Kuetz.                                15
+
+  15-16-17       Meloseira undulata (Ehr.) Kuetz.                        15
+
+  GAILLONELLA
+
+  13-14          Gaillonella nummuloides (Dillw.) Bory                   16
+
+  LYSIGONIUM
+
+  7              Lysigonium moniliforme (Muell.) Link.                   16
+
+  18-19          Lysigonium varians (Ag.) De Toni                        17
+
+  HYALODISCUS
+
+  20             Hyalodiscus scoticus (Kuetz.) Grun.                     18
+
+  21             Hyalodiscus radiatus var. arctica Grun.                 17
+
+  22             Hyalodiscus stelliger Bail.                             17
+
+  NOTE.--The figures in all of the plates, except when otherwise
+  noted, are magnified 800 diameters.
+
+
+
+[Illustration: PLATE 1]
+
+
+PLATE 2
+
+
+
+  STEPHANOPYXIS
+
+  1-2            Stephanopyxis turris (Grev.) Ralfs                      18
+
+  3              Stephanopyxis corona (Ehr.) Grun.                       18
+
+  CYCLOTELLA
+
+  4              Cyclotella meneghiniana var. stelligera Cl. and Grun.   20
+
+  5-6            Cyclotella operculata (Ag.) Kuetz.                      20
+
+  7              Cyclotella comta (Ehr.) Kuetz.                          20
+
+  8              Cyclotella meneghiniana Kuetz.                          19
+
+  9              Cyclotella striata (Kuetz.) Grun.                       19
+
+  10             Cyclotella stylorum (Br.?) V. H.                        20
+
+  11             Cyclotella antiqua Wm. Sm.                              20
+
+  12             Cyclotella meneghiniana var. stellulifera Cl. and Grun. 20
+
+  COSCINODISCUS
+
+  13             Coscinodiscus denarius A. S.                            22
+
+  14             Coscinodiscus excentricus Ehr.                          21
+
+  15-17          Coscinodiscus subtilis Ehr.                             21
+
+  16             Coscinodiscus asteromphalus Ehr.                        23
+
+  18             Coscinodiscus nitidus Greg.                             21
+
+  19             Coscinodiscus nitidulus Grun.                           21
+
+  20             Coscinodiscus excentricus var. perpusilla Grun. ?       21
+
+
+
+[Illustration: PLATE 2]
+
+
+PLATE 3
+
+
+
+  COSCINODISCUS--Continued
+
+  1-11           Coscinodiscus radiatus Ehr.                             23
+
+  2              Coscinodiscus velatus Ehr.                              22
+
+  3              Coscinodiscus biangulatus A. S.                         23
+
+  4              Coscinodiscus subaulacodiscoidalis Rattr.               23
+
+  5              Coscinodiscus lewisianus Grev.                          24
+
+  7              Coscinodiscus argus Ehr.                                23
+
+  8              Coscinodiscus lineatus Ehr.                             21
+
+  9              Coscinodiscus marginatus Ehr.                           22
+
+  10             Coscinodiscus oculus-iridis Ehr.                        23
+
+  ACTINOCYCLUS
+
+  6              Actinocyclus ellipticus var. delawarensis n. var.       27
+
+
+
+[Illustration: PLATE 3]
+
+
+PLATE 4
+
+
+
+  ACTINOPTYCHUS
+
+  1-4-6          Actinoptychus undulatus (Kuetz.) Ralfs.                 24
+
+  2              Actinoptychus undulatus (inner stratum)                 24
+
+  3              Actinoptychus heliopelta Grun. var.?                    25
+
+  5              Actinoptychus vulgaris var. interrupta n. var.          24
+
+  POLYMYXUS
+
+  7              Polymyxus coronalis L. W. Bail.                         25
+
+  AULACODISCUS
+
+  8              Aulacodiscus argus (Ehr.) A. S.                         26
+
+
+
+[Illustration: PLATE 4]
+
+
+PLATE 5
+
+
+
+  EUODIA
+
+  1              Euodia gibba Bail.                                      34
+
+  POLYMYXUS
+
+  2              Polymyxus coronalis L. W. Bail., zone view              25
+
+  EUPODISCUS
+
+  3              Eupodiscus radiatus Bail.                               28
+
+  AULISCUS
+
+  4              Auliscus cælatus Bail.                                  29
+
+  5              Auliscus sculptus (Wm. Sm.) Ralfs                       29
+
+  6              Auliscus punctatus Bail.                                28
+
+  7              Auliscus (intermediate form between A. cælatus and A.
+      sculptus)                                                          29
+
+  8              Auliscus pruinosus Bail.                                28
+
+  PSEUDAULISCUS
+
+  9              Pseudauliscus radiatus (Bail.) Rattr.                   29
+
+  10             Pseudauliscus spinosus (Christian) Rattr.               29
+
+
+
+[Illustration: PLATE 5]
+
+
+PLATE 6
+
+
+
+  ACTINOCYCLUS
+
+  1              Actinocyclus barkleyi var. aggregata Rattr.             27
+
+  2              Actinocyclus moniliformis Ralfs.                        27
+
+  BIDDULPHIA
+
+  3              Biddulphia antediluviana (Ehr.) V. H.                   32
+
+  5              Biddulphia reticulum (Ehr.)                             33
+
+  6              Biddulphia favus (Ehr.) V. H.                           31
+
+  7-8            Biddulphia alternans (Bail.) V. H.                      33
+
+  TRINACRIA
+
+  9              Trinacria pileolus (Ehr.) Grun.                         30
+
+  DITYLUM
+
+  4              Ditylum intricatum (West) Grun.                         30
+
+  TERPSINOË
+
+  10             Terpsinoë americana (Bail.) Ralfs.                      34
+
+  11             Terpsinoë novæ-cæsareæ Boyer                            34
+
+
+
+[Illustration: PLATE 6]
+
+
+PLATE 7
+
+
+
+  BIDDULPHIA
+
+  1-2-3-4        Biddulphia biddulphiana (Smith)                         31
+
+  5              Biddulphia rhombus (Ehr.) Wm. Sm.                       32
+
+  6              Biddulphia granulata Roper                              32
+
+  7              Biddulphia turgida (Ehr.) Wm. Sm.                       32
+
+  8              Biddulphia smithii (Ralfs) V. H.                        32
+
+  9              Biddulphia lævis Ehr.                                   33
+
+  10             Biddulphia lævis Ehr. Sporangial frustules (260 diam.)  33
+
+  EUNOTOGRAMMA
+
+  11             Eunotogramma læve Grun.                                 33
+
+
+
+[Illustration: PLATE 7]
+
+
+PLATE 8
+
+
+
+  RHABDONEMA
+
+  1-2-3          Rhabdonema arcuatum (Lyng.) Kuetz.                      35
+
+  4-5-6          Rhabdonema adriaticum Kuetz.                            36
+
+  7              Rhabdonema minutum Kuetz.                               36
+
+  TABELLARIA
+
+  8-9-10         Tabellaria flocculosa (Roth) Kuetz.                     36
+
+  11-12          Tabellaria fenestrata (Lyng.) Kuetz.                    36
+
+  GRAMMATOPHORA
+
+  13-14          Grammatophora marina var. subtilissima (Bail.) V. H.    37
+
+  15-16          Grammatophora angulosa var. hamulifera (Kuetz.) Grun.   37
+
+  17-18          Grammatophora marina (Lyng.) Kuetz.                     37
+
+  19-20          Grammatophora islandica Ehr.                            37
+
+  21             Grammatophora serpentina Ralfs.                         37
+
+  STRIATELLA
+
+  22-23          Striatella unipunctata (Lyng.) Ag.                      38
+
+  24             Striatella interrupta (Ehr.) Heib.                      38
+
+  ATTHEYA
+
+  25             Attheya decora West                                     38
+
+
+
+[Illustration: PLATE 8]
+
+
+PLATE 9
+
+
+
+  LICMOPHORA
+
+  1-2            Licmophora flabellata (Carm.) Ag.                       39
+
+  3-4            Licmophora lyngbyei Kuetz.                              40
+
+  5              Licmophora ehrenbergii (Kuetz.) Grun.                   40
+
+  6-7            Licmophora paradoxa (Lyng.) Ag.                         39
+
+  8-9            Licmophora ovulum Mer.                                  39
+
+  10             Licmophora baileyi (Edw.) Grun.                         40
+
+  11             Licmophora gracilis (Ehr.) Grun.                        39
+
+  12-13          Licmophora gracilis var. elongata (Kuetz.) De Toni      39
+
+  14-15          Licmophora tincta (Ag.) Grun.                           40
+
+
+
+[Illustration: PLATE 9]
+
+
+PLATE 10
+
+
+
+  MERIDION
+
+  1-2-3          Meridion circulare (Grev.) Ag.                          40
+
+  DIATOMA
+
+  4              Diatoma vulgare var. grande (Wm. Sm.) Grun.             42
+
+  5-6            Diatoma anceps (Ehr.) Kirchn.                           42
+
+  7-8            Diatoma hiemale (Lyng.) Heib.                           42
+
+  9-10           Diatoma vulgare Bory.                                   42
+
+  PLAGIOGRAMMA
+
+  11             Plagiogramma tessellatum Grev.                          43
+
+  12             Plagiogramma obesum Grev.                               43
+
+  13             Plagiogramma pygmæum Grev.                              43
+
+  14             Plagiogramma wallichianum Grev.                         43
+
+  EUNOTOGRAMMA
+
+  15             Eunotogramma læve Grun.                                 33
+
+  OPEPHORA
+
+  16-19          Opephora schwartzii (Grun.) Petit.                      43
+
+  17             Opephora pinnata var. lanceolata n. var.                44
+
+  18             Opephora pacifica (Grun.) Petit.                        43
+
+  FRAGILARIA
+
+  20-21          Fragilaria virescens Ralfs.                             44
+
+  22-23          Fragilaria arctica Grun.                                44
+
+  24-25-27-28-29 Fragilaria undata Wm. Sm.                               44
+
+  26             Fragilaria undata Wm. Sm., var.?                        44
+
+  30             Fragilaria construens (Ehr.) Grun.                      45
+
+  31             Fragilaria harrisonii (Wm. Sm.) Grun.                   45
+
+  34             Fragilaria capucina var. mesolepta Rab.                 45
+
+  35             Fragilaria parasitica (Wm. Sm.)                         45
+
+  36             Fragilaria sp. ?                                        45
+
+  37             Fragilaria linearis Cstr.                               45
+
+  RHAPHONEIS
+
+  38             Rhaphoneis amphiceros Ehr.                              46
+
+  39-40          Rhaphoneis amphiceros var. rhombica Grun.               46
+
+  41             Rhaphoneis belgica var. intermedia Grun.                46
+
+  SYNEDRA
+
+  32-33          Synedra radians Kuetz.                                  49
+
+
+
+[Illustration: PLATE 10]
+
+
+PLATE 11
+
+
+
+  SYNEDRA--Continued
+
+  1-5-6          Synedra ulna (Nitzsch) Ehr. Sporangial                  47
+
+  2              Synedra danica Kuetz.                                   48
+
+  3              Synedra biceps (Kuetz.) A. S.                           48
+
+  4-7-11         Synedra ulna (Nitzsch) Ehr.                             47
+
+  8              Synedra capitata Ehr.                                   48
+
+  9-18           Synedra acus Kuetz.                                     48
+
+  10             Synedra fulgens (Grev.) Wm. Sm.                         50
+
+  12-13          Synedra goulardi Bréb.                                  48
+
+  14-15-16       Synedra pulchella (Ralfs) Kuetz.                        48
+
+  17             Synedra pulchella var. abnormis Macchiati?              48
+
+
+
+[Illustration: PLATE 11]
+
+
+PLATE 12
+
+
+
+  SYNEDRA--Continued
+
+  1              Synedra oxyrhynchus var. undulata Grun.                 48
+
+  2              Synedra pulchella var. flexella n. var.                 49
+
+  3              Synedra affinis Kuetz.                                  50
+
+  4              Synedra affinis var. tabulata (Ag.) V. H.               50
+
+  5-6            Synedra vaucheriæ var. parvula (Kuetz.) Rab.            49
+
+  7              Synedra affinis var. parva (Kuetz.) V. H.               50
+
+  8              Synedra radians (Kuetz.) H. L. S.                       49
+
+  DIMEROGRAMMA
+
+  9-10           Dimerogramma marinum (Greg.)                            46
+
+  11             Dimerogramma surirella (Ehr.) Grun.                     46
+
+  12-13-14       Dimerogramma minus (Greg.) Ralfs.                       47
+
+  TRACHYSPHENIA
+
+  15             Trachysphenia australis Petit.                          47
+
+  ACTINELLA
+
+  16-17-18       Actinella punctata Lewis.                               54
+
+  ASTERIONELLA
+
+  19-20-21       Asterionella formosa Hass.                              50
+
+  22             Asterionella inflata Heib.                              50
+
+  EUNOTIA
+
+  23             Eunotia hemicyclus (Ehr.) Ralfs                         53
+
+  24-25          Eunotia lunaris (Ehr.) Grun.                            53
+
+
+
+[Illustration: PLATE 12]
+
+
+PLATE 13
+
+
+
+  EUNOTIA--Continued
+
+  1-2            Eunotia major (Wm. Sm.) Rab.                            51
+
+  3              Eunotia gracilis (Ehr.) Rab.                            51
+
+  4              Eunotia major (Wm. Sm.) Rab. (intermediate form)        51
+
+  5              Eunotia prærupta Ehr.                                   53
+
+  6-7            Eunotia pectinalis (Kuetz.)                             52
+
+  8-10           Eunotia pectinalis var. undulata Ralfs                  52
+
+  9              Eunotia pectinalis var. solierolii (Kuetz.)             52
+
+  11             Eunotia luna Ehr. var.?                                 52
+
+  12             Eunotia pectinalis var. ventricosa Grun.                52
+
+  13             Eunotia robusta Ralfs (E. scalaris Ehr.)                53
+
+  14             Eunotia robusta Ralfs (E. prioritis Ehr.)               53
+
+  15             Eunotia robusta Ralfs (E. decadon Ehr.)                 53
+
+  16             Eunotia robusta Ralfs (E. octodon Ehr.)                 53
+
+  17-22          Eunotia robusta Ralfs (E. heptodon Ehr.)                53
+
+  18             Eunotia bactriana Ehr.                                  54
+
+  19             Eunotia prærupta var. bidens Grun.                      53
+
+  20             Eunotia bidentula Wm. Sm.                               54
+
+  21             Eunotia robusta Ralfs (E. diadema Ehr.)                 53
+
+  23             Eunotia prærupta Ehr. var.?                             53
+
+  24             Eunotia robusta Ralfs (E. triodon Ehr.)                 53
+
+  25             Eunotia robusta Ralfs (E. tetraodon Ehr.)               53
+
+  26             Eunotia formica Ehr. var.?                              54
+
+  27             Eunotia biceps Ehr.                                     53
+
+  28-29          Eunotia sp.?                                            54
+
+  30-31          Eunotia veneris Kuetz.                                  52
+
+  32             Eunotia nymanniana Grun.                                51
+
+
+
+[Illustration: PLATE 13]
+
+
+PLATE 14
+
+
+
+  AMPHIPRORA
+
+  1-2            Amphiprora pulchra Bail.                                68
+
+  3              Amphiprora alata Kuetz.                                 68
+
+  4              Amphiprora conspicua Grev.                              68
+
+  5              Amphiprora paludosa Wm. Sm.                             68
+
+  6-7            Amphiprora ornata Bail.                                 68
+
+  TROPIDONEIS
+
+  8-9            Tropidoneis lepidoptera (Greg.) Cleve.                  69
+
+  SCOLIOTROPIS
+
+  10-11          Scoliotropis latestriata var. amphora Cleve.            69
+
+
+
+[Illustration: PLATE 14]
+
+
+PLATE 15
+
+
+
+  AMPHORA
+
+  1              Amphora robusta Greg.                                   65
+
+  3              Amphora crassa Greg.                                    65
+
+  4              Amphora obtusa Greg.                                    67
+
+  5-6-19         Amphora proteus Greg.                                   65
+
+  7              Amphora ovalis (Bréb.) Kuetz.                           65
+
+  8-18           Amphora coffæiformis (Ag.) Kuetz.                       66
+
+  9-10           Amphora lineolata Ehr.                                  66
+
+  11             Amphora areolata Grun.                                  66
+
+  12-21          Amphora ostrearia Bréb.                                 66
+
+  13             Amphora lævis Greg.                                     66
+
+  14-15          Amphora ocellata var. cingulata Cleve.                  67
+
+  16             Amphora angusta var. culensteinii Grun.                 67
+
+  17             Amphora arenaria Donk.                                  67
+
+  20             Amphora acuta Greg.                                     66
+
+  AURICULA
+
+  2              Auricula mucronata (H. L. Smith) Peragallo              69
+
+
+
+[Illustration: PLATE 15]
+
+
+PLATE 16
+
+
+
+  ACHNANTHES
+
+  1-2            Achnanthes longipes Ag.                                 58
+
+  3              Achnanthes brevipes Ag.                                 59
+
+  4-5-6          Achnanthes subsessilis Kuetz.                           59
+
+  7-8            Achnanthes inflata (Kuetz.) Grun.                       59
+
+  9              Achnanthes coarctata (Bréb.) Grun.                      59
+
+  10-11-12       Achnanthes lanceolata (Bréb.) Grun.                     59
+
+  13             Achnanthes danica (Floegel) Grun. (lower valve)         60
+
+  14-15          Achnanthes exigua Grun.                                 59
+
+  16-17          Achnanthes linearis forma curta H. L. Smith             59
+
+  COCCONEIS
+
+  18             Cocconeis scutellum var.?                               57
+
+  19-20          Cocconeis placentula Ehr.                               57
+
+  21             Cocconeis scutellum Ehr. (upper valve)                  57
+
+  22             Cocconeis dirupta Greg. (lower valve)                   58
+
+  23-24          Cocconeis pediculus Ehr.                                57
+
+  25-26          Cocconeis pellucida Grun.                               58
+
+  27-28          Cocconeis scutellum var. ornata Grun.                   57
+
+  29             Cocconeis placentula var. lineata (Ehr.) V. H.          58
+
+  ANORTHONEIS
+
+  30-31          Anorthoneis excentrica (Donk.) Grun.                    56
+
+
+
+[Illustration: PLATE 16]
+
+
+PLATE 17
+
+
+
+  FRUSTULIA
+
+  1              Frustulia lewisiana (Grev.) De Toni                     77
+
+  2              Frustulia rhomboides (Ehr.) De Toni                     77
+
+  3              Frustulia rhomboides var. amphipleuroides Grun.         77
+
+  4              Frustulia vulgaris (Thwaites) De Toni                   77
+
+  5              Frustulia interposita (Lewis) De Toni                   78
+
+  6              Frustulia rhomboides var. saxonica (Rab.) De Toni       77
+
+  BREBISSONIA
+
+  7              Brébissonia boeckii (Kuetz.) Grun.                      79
+
+  8              Brébissonia palmerii n. sp.                             80
+
+  AMPHIPLEURA
+
+  9              Amphipleura pellucida Kuetz.                            78
+
+  10-11          Amphipleura rutilans (Trentepohl) Cl.                   78
+
+  ANOMOEONEIS
+
+  12             Anomoeoneis serians (Bréb.) Cl.                         80
+
+  13             Anomoeoneis serians forma minor                         80
+
+  14             Anomoeoneis follis (Ehr.) Cl.                           80
+
+  TRACHYNEIS
+
+  15             Trachyneis aspera var. intermedia Grun.                 70
+
+  MASTOGLOIA
+
+  16             Mastogloia kinsmanii Lewis                              87
+
+  17             Mastogloia angulata Lewis                               87
+
+  18             Mastogloia lanceolata Thwaites                          87
+
+  19             Mastogloia smithii Thwaites                             87
+
+  20             Mastogloia elegans Lewis                                87
+
+  21-22-23       Mastogloia apiculata Wm. Sm.                            87
+
+  24             Mastogloia exigua Lewis                                 87
+
+
+
+[Illustration: PLATE 17]
+
+
+PLATE 18
+
+
+
+  CYMBELLA
+
+  1              Cymbella aspera (Ehr.) Cl.                              61
+
+  2              Cymbella cymbiformis (Kuetz.) Bréb.                     62
+
+  3              Cymbella cistula (Hempr.) Kirchn.                       62
+
+  4              Cymbella lanceolata (Ehr.) Kirchn.                      62
+
+  5              Cymbella mexicana (Ehr.) A. S.                          62
+
+  6              Cymbella naviculiformis Auerswald.                      60
+
+  7              Cymbella tumida (Bréb.) V. H.                           62
+
+  8              Cymbella philadelphica n. sp.                           63
+
+  9              Cymbella ehrenbergii Kuetz.                             60
+
+  10             Cymbella heteropleura (Ehr.) Kuetz.                     60
+
+  11             Cymbella rhomboidea n. sp.                              63
+
+  12             Cymbella turgida (Greg.) Cl. var.?                      63
+
+  13             Cymbella sinuata Greg.                                  61
+
+  14             Cymbella ventricosa Kuetz.                              62
+
+  15-19          Cymbella excisa (Kuetz.) De Toni.                       61
+
+  16             Cymbella amphicephala Nægeli.                           61
+
+  17             Cymbella cuspidata Kuetz.                               60
+
+  18             Cymbella affinis Kuetz.                                 61
+
+  20             Cymbella gracilis (Rab.) Cl.                            64
+
+  21             Cymbella prostrata (Berk.) Cl.                          63
+
+  22             Cymbella ventricosa Kuetz.?                             62
+
+  23             Cymbella turgida (Greg.) Cl.                            63
+
+  24             Cymbella triangulum (Ehr.) Cl.                          63
+
+  25             Cymbella lacustris (Ag.) Cl.                            64
+
+
+
+[Illustration: PLATE 18]
+
+
+PLATE 19
+
+
+
+  GOMPHONEIS
+
+  1              Gomphoneis mamilla (Ehr.) Cl.                           70
+
+  2              Gomphoneis herculaneum (Ehr.) Cl.                       70
+
+  GOMPHONEMA
+
+  3              Gomphonema montanum Schum.                              71
+
+  4              Gomphonema geminatum Lyng.                              71
+
+  5              Gomphonema acuminatum var. turris (Ehr.) Cl.            71
+
+  6-12           Gomphonema lanceolatum var. insignis (Greg.) Cl.        71
+
+  7              Gomphonema acuminatum var. coronata (Ehr.) Cl.          71
+
+  8              Gomphonema constrictum Ehr.                             72
+
+  9-10           Gomphonema sphærophorum Ehr.                            72
+
+  11             Gomphonema acuminatum var. turris (Ehr.) Cl.?           71
+
+  13             Gomphonema ventricosum Greg.                            73
+
+  14             Gomphonema intricatum Kuetz.                            72
+
+  15             Gomphonema æquale Greg.                                 72
+
+  16             Gomphonema sarcophagus Greg.                            72
+
+  17             Gomphonema parvulum var. micropus (Kuetz.) Cl.          73
+
+  18-19          Gomphonema angustatum Kuetz.                            72
+
+  20             Gomphonema acuminatum var. trigonocephala (Ehr.) Cl.    71
+
+  21             Gomphonema augur Ehr.                                   72
+
+  22             Gomphonema capitatum Ehr.                               72
+
+  23             Gomphonema olivaceum Lyng.                              73
+
+  24             Gomphonema brasiliense var. demeraræ Grun.?             73
+
+  RHOICOSPHENIA
+
+  25-26-27       Rhoicosphenia curvata (Kuetz.) Grun.                    56
+
+
+
+[Illustration: PLATE 19]
+
+
+PLATE 20
+
+
+
+  DICTYONEIS
+
+  1              Dictyoneis marginata var. maxima n. var.                79
+
+  2              Dictyoneis marginata var. commutata Cleve.              79
+
+  3              Dictyoneis marginata var. typica Cleve.                 78
+
+  DIPLONEIS
+
+  4              Diploneis crabro var. pandura (Bréb.) Cl.               85
+
+  6              Diploneis campylodiscus (Grun.) Cl.                     86
+
+  7-8            Diploneis gruendleri (A. S.) Cl.                        85
+
+  9              Diploneis crabro Ehr. var.?                             85
+
+  10             Diploneis excentrica n. sp.                             85
+
+  11             Diploneis fusca var. delicata (A. S.) Cl.               85
+
+  12             Diploneis puella (Schum.) Cl.                           85
+
+  13             Diploneis crabro var. pandurella Cl.?                   85
+
+  14             Diploneis elliptica (Kuetz.) Cl.                        84
+
+  15             Diploneis crabro var. expleta (A. S.) Cl.               85
+
+  16             Diploneis geminata (Grev.) Cl.                          86
+
+  17             Diploneis smithii (Bréb.) Cl.                           84
+
+  NAVICULA
+
+  5              Navicula lyra Ehr. var.?                                93
+
+
+
+[Illustration: PLATE 20]
+
+
+PLATE 21
+
+
+
+  CALONEIS
+
+  1              Caloneis permagna (Bail.) Cl.                           82
+
+  2              Caloneis permagna var. lewisiana n. var.                82
+
+  3              Caloneis silicula (Ehr.) Cl.                            81
+
+  4              Caloneis silicula var. inflata (Grun.) Cl.              81
+
+  5              Caloneis brevis var. vexans (Grun.) Cl.                 82
+
+  6-7            Caloneis wardii Cl.                                     82
+
+  8              Caloneis trinodis (Lewis)                               81
+
+  9              Caloneis trinodis (Lewis) var.?                         81
+
+  10             Caloneis powellii (Lewis) Cl.                           83
+
+  18             Caloneis formosa (Greg.) Cl.                            82
+
+  NEIDIUM
+
+  11             Neidium affine (Ehr.) Pfitzer                           83
+
+  12             Neidium affine var. genuina forma minor Cl.             83
+
+  13             Neidium affine var. amphirhyncus (Ehr.) Cl.             83
+
+  14             Neidium amphigomphus (Ehr.) Pfitzer.                    83
+
+  15             Neidium hitchcockii (Ehr.) Cl.                          84
+
+  16             Neidium productum (Wm. Sm.) Cl.                         83
+
+  17             Neidium iridus (Ehr.) Cl.                               84
+
+
+
+[Illustration: PLATE 21]
+
+
+PLATE 22
+
+
+
+  PLEUROSIGMA
+
+  1              Pleurosigma strigosum Wm. Sm.                           74
+
+  2              Pleurosigma rigidum Wm. Sm.                             75
+
+  3              Pleurosigma angulatum (Quekett) Cl.                     74
+
+  4              Pleurosigma obscurum Wm. Sm.                            74
+
+  5              Pleurosigma formosum Wm. Sm.                            73
+
+  6              Pleurosigma naviculaceum Bréb.                          74
+
+  7              Pleurosigma æstuarii Bréb.                              74
+
+  8              Pleurosigma virginiacum H. L. Smith                     74
+
+
+
+[Illustration: PLATE 22]
+
+
+PLATE 23
+
+
+
+  GYROSIGMA
+
+  1              Gyrosigma strigilis (Wm. Sm.) Cl.                       76
+
+  2              Gyrosigma balticum (Ehr.) Cl.                           75
+
+  3              Gyrosigma hippocampus (Ehr.)                            75
+
+  4              Gyrosigma simile (Grun.)                                76
+
+  5              Gyrosigma acuminatum (Kuetz.) Cl.                       76
+
+  6              Gyrosigma scalproides (Rab.) Cl.                        76
+
+  7              Gyrosigma parkeri var. stauroneioides Grun.             75
+
+  8              Gyrosigma spencerii var. nodifera Grun.                 76
+
+  9              Gyrosigma fasciola (Ehr.) Cl.                           77
+
+
+
+[Illustration: PLATE 23]
+
+
+PLATE 24
+
+
+
+  NAVICULA
+
+  1              Navicula maculata (Bail.) Cl.                           90
+
+  2              Navicula prætexta Ehr.                                  92
+
+  3              Navicula latissima Greg.                                90
+
+  4              Navicula irrorata Grev.                                 93
+
+  5              Navicula latissima var. elongata (Pant.) Cl.            91
+
+  6              Navicula fuchsii Pant.                                  91
+
+
+
+[Illustration: PLATE 24]
+
+
+PLATE 25
+
+
+
+  NAVICULA
+
+  1              Navicula tumida (Bréb.) Cl.                             99
+
+  2              Navicula brasiliensis var. bicuneata Cl. forma
+      constricta.                                                        92
+
+  3              Navicula delawarensis Grun.                             92
+
+  4-6            Navicula pusilla Wm. Sm.                                91
+
+  5              Navicula humerosa Bréb.                                 91
+
+  7              Navicula spectabilis var. emarginata Cl.                94
+
+  8              Navicula pusilla var. subcapitata n. var.               91
+
+  9              Navicula punctulata Wm. Sm.                             92
+
+  10             Navicula lyra Ehr.                                      93
+
+  11             Navicula hennedyi var. manca A. S.                      93
+
+  12             Navicula hennedyi Wm. Sm.                               93
+
+  13             Navicula lyra var. dilatata A. S.                       93
+
+  14             Navicula yarrensis Grun.                               101
+
+  15             Navicula yarrensis Grun. (smaller form)                101
+
+  16             Navicula yarrensis Grun. var.?                         101
+
+
+
+[Illustration: PLATE 25]
+
+
+PLATE 26
+
+
+
+  NAVICULA
+
+  1-2            Navicula cuspidata Kuetz.                              100
+
+  3              Navicula cuspidata var. ambigua (Ehr.) Cl.             100
+
+  4              Navicula spicula (Hickie) Cl.                          100
+
+  5              Navicula integra Wm. Sm.                                99
+
+  6              Navicula mutica Kuetz.                                  97
+
+  8              Navicula americana Ehr.                                 98
+
+  9              Navicula pupula var. bacillarioides Grun.               98
+
+  10             Navicula bacillum Ehr.                                  98
+
+  11             Navicula semen Ehr.                                     98
+
+  12             Navicula atomus Nægeli.                                100
+
+  13             Navicula minima Grun.                                   98
+
+  14             Navicula ramosissima (Ag.) Cl.                          95
+
+  15             Navicula crucigera (Wm. Sm.) Cl.                       100
+
+  16             Navicula viridula var. rostellata Kuetz.                95
+
+  17             Navicula radiosa Kuetz.                                 94
+
+  19             Navicula gracilis var. schizonemoides (Ehr.) V. H.      95
+
+  20             Navicula peregrina Ehr.                                 94
+
+  21             Navicula cyprinus (Wm. Sm.)                             95
+
+  22             Navicula reinhardtii Grun.                              95
+
+  23             Navicula lanceolata var. arenaria (Donk.) Cl.           95
+
+  24             Navicula salinarum Grun.                                95
+
+  25             Navicula gastrum Ehr.                                   96
+
+  26             Navicula anglica Ralfs.                                 96
+
+  DIPLONEIS
+
+  7              Diploneis oculata (Bréb.) Cl.                           86
+
+  STAURONEIS
+
+  18             Stauroneis frickei var. angusta n. var.                 88
+
+
+
+[Illustration: PLATE 26]
+
+
+PLATE 27
+
+
+
+  STAURONEIS--Continued
+
+  1              Stauroneis phoenicenteron Ehr.                          88
+
+  2              Stauroneis acuta Wm. Sm.                                89
+
+  3              Stauroneis americana A. S.                              89
+
+  4              Stauroneis anceps var.?                                 88
+
+  5              Stauroneis anceps var. gracilis (Ehr.) Cl.              88
+
+  6              Stauroneis salina Wm. Sm.                               89
+
+  7              Stauroneis anceps var. amphicephala (Kuetz.) Cl.        88
+
+  8              Stauroneis anceps var.?                                 88
+
+  9              Stauroneis anceps var.?                                 88
+
+  10             Stauroneis crucicula (Grun.) Cl.                        89
+
+  11             Stauroneis smithii Grun.                                89
+
+  NAVICULA
+
+  12             Navicula lacustris Greg.                                92
+
+  13             Navicula hasta Pant.                                    97
+
+  14             Navicula hasta var. punctata n. var.                    97
+
+  15             Navicula punctata var. asymmetrica Lagerstedt           92
+
+  16             Navicula dicephala Wm. Sm.                              96
+
+  17             Navicula placenta Ehr.                                  94
+
+  18-19          Navicula inflexa Greg.                                  96
+
+  20             Navicula pinnata Pant.?                                 96
+
+  21             Navicula oblonga Kuetz.                                 97
+
+  22             Navicula pennata A. S.                                  96
+
+  23             Navicula pygmæa Kuetz.                                  94
+
+  24             Navicula humilis Donk.                                  96
+
+
+
+[Illustration: PLATE 27]
+
+
+PLATE 28
+
+
+
+  PINNULARIA
+
+  1              Pinnularia nobilis Ehr.                                103
+
+  2              Pinnularia major var. pulchella n. var.                102
+
+  3              Pinnularia dactylus Ehr.                               103
+
+  4              Pinnularia major (Kuetz.) Wm. Sm.                      102
+
+
+
+[Illustration: PLATE 28]
+
+
+PLATE 29
+
+
+
+  PINNULARIA--Continued
+
+  1              Pinnularia gentilis (Donk.) Cl.                        103
+
+  2              Pinnularia viridis Nitzsch.                            104
+
+  3              Pinnularia dactylus var. dariana (A. S.) Cl.           103
+
+  4              Pinnularia viridis var. fallax Cl.                     104
+
+  5              Pinnularia socialis Palmer                             104
+
+  6              Pinnularia æstuarii Cl.                                105
+
+  7              Pinnularia rectangulata (Greg.) Cl.                    110
+
+  8              Pinnularia trigonocephala Cl.                          103
+
+  9              Pinnularia major (Kuetz.) Wm. Sm. (small form near P.
+      viridis)                                                          102
+
+  10             Pinnularia dactylus var. demeraræ Cl.                  103
+
+  11             Pinnularia mormonorum (Grun.)                          107
+
+  12             Pinnularia brébissonii (Kuetz.) Cl.                    107
+
+  13             Pinnularia mesolepta Ehr.                              105
+
+  14             Pinnularia termes var. stauroneiformis V. H.           106
+
+  15             Pinnularia molaris (Grun.) Cl.                         105
+
+  16             Pinnularia braunii Grun.                               106
+
+  17             Pinnularia termes (Ehr.) A. S.                         106
+
+  18             Pinnularia appendiculata (Ag.) Cl.                     106
+
+  19             Pinnularia microstauron (Ehr.) Cl. var.?               106
+
+  20             Pinnularia subcapitata Greg.                           105
+
+
+
+[Illustration: PLATE 29]
+
+
+PLATE 30
+
+
+
+  PINNULARIA--Continued
+
+  1              Pinnularia cardinaliculus Cl.                          107
+
+  2              Pinnularia viridis var. fallax Cl.? (var. B., Wm.
+      Sm.?).                                                            104
+
+  3              Pinnularia legumen Ehr.                                107
+
+  4              Pinnularia legumen var.?                               107
+
+  5              Pinnularia gibba (Kuetz.) V. H.                        109
+
+  6              Pinnularia mesogongyla (Ehr.) Cl.                      109
+
+  7              Pinnularia acrosphæria (Bréb.) Cl.                     108
+
+  8              Pinnularia acrosphæria var. turgidula Grun.            108
+
+  9              Pinnularia tabellaria (Ehr.) Cl. var.?                 110
+
+  10             Pinnularia leptosoma Grun.                             105
+
+  11             Pinnularia stauroptera var. interrupta Cl.             110
+
+  12             Pinnularia stomatophora (Grun.) Cl.                    109
+
+  13             Pinnularia stauroptera (Grun.) Cl.                     110
+
+  14             Pinnularia parva (Ehr.) Cl. var.?                      108
+
+  15-19          Pinnularia nodosa forma capitata Cl.                   108
+
+  16             Pinnularia subcapitata var. paucistriata Grun.         105
+
+  17             Pinnularia viridis Nitzsch var.                        104
+
+  18             Pinnularia viridis var. caudata n. var.                104
+
+  20             Pinnularia mesolepta var. stauroneiformis Grun.        105
+
+  21             Pinnularia polyonca (Bréb.) Lewis.                     108
+
+  22             Pinnularia borealis Ehr.                               109
+
+  23             Pinnularia lata (Bréb.) Wm. Sm.                        109
+
+  24             Pinnularia borealis var. scalaris (Ehr.) Cl.           109
+
+  25             Pinnularia blandita n. sp.                             108
+
+
+
+[Illustration: PLATE 30]
+
+
+PLATE 31
+
+
+
+  NAVICULA
+
+  1              Navicula elegans Wm. Sm.                               101
+
+  2              Navicula elegans var. cuspidata Cl.                    101
+
+  3-4            Navicula grevillei (Ag.) Cl.                            99
+
+  5              Navicula libellus Greg.                                 99
+
+  6-7            Navicula palpebralis Bréb.                             101
+
+  8              Navicula rhyncocephala Kuetz.                           97
+
+  9              Navicula cryptocephala Kuetz.                           97
+
+  10             Navicula longa (Greg.) Ralfs.                           97
+
+  PINNULARIA
+
+  11             Pinnularia brébissonii (Kuetz.) Cl.                    107
+
+  12             Pinnularia borealis Ehr.                               109
+
+  13             Pinnularia divergens var. elliptica Grun.              107
+
+  EPITHEMIA
+
+  14             Epithemia turgida (Ehr.) Kuetz.                        111
+
+  15-21          Epithemia argus Kuetz.                                 111
+
+  16             Epithemia argus var.?                                  111
+
+  17             Epithemia muelleri A. S.                               111
+
+  18             Epithemia zebra var. proboscidea (Kuetz.) Grun.        112
+
+  19             Epithemia gibberula var. producta Grun.                112
+
+  20             Epithemia musculus Kuetz.                              112
+
+  22             Epithemia musculus var. constricta (Bréb.) V. H.       112
+
+  RHOPALODIA
+
+  23             Rhopalodia gibba (Kuetz.) Mueller                      112
+
+  24             Rhopalodia ventricosa (Kuetz.) Mueller                 113
+
+
+
+[Illustration: PLATE 31]
+
+
+PLATE 32
+
+
+
+  NITZSCHIA
+
+  1              Nitzschia circumsuta (Bail.) Grun.                     118
+
+  2              Nitzschia plana Wm. Sm.                                117
+
+  3              Nitzschia granulata Grun.                              116
+
+  4              Nitzschia navicularis (Bréb.) Grun.                    116
+
+  5              Nitzschia panduriformis var. minor Grun.               117
+
+  6              Nitzschia apiculata (Greg.) Grun.                      117
+
+  7              Nitzschia tabellaria Grun.                             119
+
+  8              Nitzschia tryblionella Hantzsch                        116
+
+  10-11          Nitzschia bilobata Wm. Sm.                             118
+
+  12             Nitzschia litoralis var. delawarensis Grun.            118
+
+  13             Nitzschia acuminata (Wm. Sm.) Grun.                    117
+
+  14-25          Nitzschia amphibia Grun.                               122
+
+  15             Nitzschia palea (Kuetz.) Wm. Sm.                       122
+
+  16             Nitzschia fluminensis Grun.                            120
+
+  17             Nitzschia obtusa var. scalpelliformis Grun.            121
+
+  18             Nitzschia linearis (Ag.) Wm. Sm.                       122
+
+  19             Nitzschia communis Rab.                                122
+
+  20             Nitzschia clausii Hantzsch.                            121
+
+  21             Nitzschia epithemioides Grun.                          118
+
+  24             Nitzschia vermicularis (Kuetz.) Wm. Sm.                120
+
+  HANTZSCHIA
+
+  9              Hantzschia amphioxys (Ehr.) Grun.                      113
+
+  22             Hantzschia marina (Donk.) Grun.                        114
+
+  23             Hantzschia virgata (Roper) Grun.                       114
+
+
+
+[Illustration: PLATE 32]
+
+
+PLATE 33
+
+
+
+  NITZSCHIA
+
+  1              Nitzschia longissima (Bréb.) Ralfs                     123
+
+  2              Nitzschia intermedia Hantzsch                          122
+
+  3              Nitzschia spectabilis var. americana Grun.             122
+
+  4-5            Nitzschia sigmatella Greg.                             121
+
+  6              Nitzschia scalaris (Ehr.) Wm. Sm.                      119
+
+  7              Nitzschia macilenta Greg.                              120
+
+  8              Nitzschia insignis Greg.                               119
+
+  9              Nitzschia vermicularis (Kuetz.) Hantzsch               120
+
+  10             Nitzschia longissima forma parva V. H.                 123
+
+  11             Nitzschia reversa Wm. Sm.                              123
+
+  12             Nitzschia acicularis (Kuetz.) Wm. Sm.                  123
+
+  13-14          Nitzschia paxillifer (O. F. Mueller) Heib.             119
+
+  HOMOEOCLADIA
+
+  15             Homoeocladia filiformis Wm. Sm.                        123
+
+
+
+[Illustration: PLATE 33]
+
+
+PLATE 34
+
+
+
+  SURIRELLA
+
+  1              Surirella striatula Turpin                             125
+
+  2              Surirella anceps Lewis                                 128
+
+  3              Surirella intermedia Lewis                             128
+
+  4              Surirella arctissima A. S.                             128
+
+  5-6            Surirella delicatissima Lewis                          128
+
+  7              Surirella intermedia Lewis forma minor?                128
+
+  CYMATOPLEURA
+
+  8-9            Cymatopleura solea (Bréb.) Wm. Sm.                     129
+
+
+
+[Illustration: PLATE 34]
+
+
+PLATE 35
+
+
+
+  SURIRELLA
+
+  1              Surirella fastuosa Ehr.                                127
+
+  2              Surirella biseriata (Ehr.) Bréb.                       124
+
+  3              Surirella splendida (Ehr.) Kuetz.                      125
+
+  4              Surirella crumena Bréb.                                126
+
+  5              Surirella ovalis Bréb.                                 126
+
+  6              Surirella tenera Greg.                                 125
+
+  7              Surirella recedens A. S.                               127
+
+  8              Surirella linearis Wm. Sm.                             124
+
+  9              Surirella oblonga Ehr.?                                127
+
+  10             Surirella cruciata A. S.                               127
+
+  11             Surirella gracilis Grun.                               127
+
+  12-13          Surirella amphioxys Wm. Sm.                            124
+
+
+
+[Illustration: PLATE 35]
+
+
+PLATE 36
+
+
+
+  SURIRELLA--Continued
+
+  1              Surirella elegans Ehr.                                 125
+
+  2              Surirella robusta Ehr.                                 124
+
+  3              Surirella febigerii Lewis                              128
+
+  4              Surirella gemma Ehr.                                   125
+
+  5              Surirella guatimalensis Ehr.                           126
+
+  6              Surirella panduriformis Wm. Sm.                        126
+
+  7-9            Surirella pinnata Wm. Sm.                              126
+
+  8              Surirella angusta Kuetz.                               127
+
+
+
+[Illustration: PLATE 36]
+
+
+PLATE 37
+
+
+
+  CYMATOPLEURA
+
+  1              Cymatopleura elliptica (Bréb.) Wm. Sm.                 129
+
+  2              Cymatopleura elliptica forma spiralis                  129
+
+  3-4            Cymatopleura marina Lewis                              129
+
+  CAMPYLODISCUS
+
+  5              Campylodiscus hibernicus Ehr.                          130
+
+  6              Campylodiscus echeneis Ehr.                            130
+
+
+
+[Illustration: PLATE 37]
+
+
+PLATE 38
+
+
+
+  1              Amphora gigantea var. fusca A. S.                       65
+
+  2              Meloseira crenulata (Ehr.) Kuetz.                       15
+
+  3-4            Licmophora baileyi (Edw.) Grun.                         40
+
+  5              Coscinodiscus polyacanthus Grun.                        22
+
+  6-7            Ditylum intricatum (West) Grun.                         30
+
+  8              Pyxidicula cruciata Ehr.                                19
+
+  9              Gyrosigma scalproides (Rab.) Cl.                        76
+
+  10             Coscinodiscus asteromphalus var. omphalantha (Ehr.)
+      Grun.                                                              23
+
+  11             Rhabdonema minutum Kuetz.                               36
+
+  12             Gyrosigma kuetzingii (Grun.) Cl.                        76
+
+  13             Gyrosigma prolongatum (Wm. Sm.) Cl.                     76
+
+  14             Cymbella parva (Wm. Sm.) Cl.                            61
+
+  15             Gomphoneis herculaneum (Ehr.) Cl. (zone view)           70
+
+  16             Cymbella ventricosa Kuetz.                              62
+
+  17-18          Eunotia sp. (abnormal?)                                 54
+
+
+
+[Illustration: PLATE 38]
+
+
+PLATE 39
+
+
+
+  1              Nitzschia spectabilis var. americana Grun. (zone view) 122
+
+  2              Nitzschia panduriformis Greg.                          117
+
+  3              Hantzschia amphioxys (Ehr.) Grun.                      113
+
+  4              Hantzschia amphioxys var. major Grun.                  114
+
+  5              Nitzschia dubia Wm. Sm.                                118
+
+  6              Nitzschia amphioxys Wm. Sm.                            114
+
+  7              Nitzschia compressa (Bail.)                            116
+
+  8              Nitzschia compressa var. minor H. L. Smith             116
+
+  9              Surirella intermedia Lewis (zone view)                 128
+
+  10             Surirella arctissima A. S. forma minor                 128
+
+  11             Surirella ovalis Bréb.                                 126
+
+  12             Surirella biseriata (Ehr.) Bréb.                       124
+
+  13             Nitzschia sigma (Kuetz.) Wm. Sm.                       121
+
+  14             Nitzschia obtusa var. flexella H. L. Smith             121
+
+  15             Stauroneis legumen Ehr.                                 89
+
+  16             Nitzschia obtusa Wm. Sm.                               121
+
+
+
+[Illustration: PLATE 39]
+
+
+PLATE 40
+
+
+
+  1              Caloneis liber (Wm. Sm.) Cl.                            81
+
+  2              Anomoeoneis sphærophora (Kuetz.) Cl.                    80
+
+  3              Nitzschia spathulata Bréb.                             120
+
+  4              Stauroneis ? abnormal                                   89
+
+  5              Navicula ? abnormal                                    101
+
+  6              Podocystis adriatica Kuetz.                            129
+
+  7              Nitzschia dissipata (Kuetz.) Grun.                     120
+
+  8              Cymbella ventricosa Kuetz. (zone view)                  62
+
+  9              Navicula radiosa Kuetz. (zone view)                     94
+
+  10             Detail of Rhabdonema arcuatum (Lyng.) Kuetz.            35
+
+  11             Diatoma anceps (Ehr.) Kirchn. (containing
+      chromataphores)                                                    42
+
+  12             Coscinodiscus asteromphalus Ehr. (trans. section, after
+      Pelletan)                                                          23
+
+  13-14-15       Transverse section (diagram) of Pinnularia showing
+      straight, oblique and grooved raphes                              101
+
+  16             Transverse section (diagram) of Biddulphia favus
+      showing inner punctate stratum (after Deby)                        31
+
+  17             Transverse (ideal) section of Surirella                124
+
+  18-19          Transverse (ideal) section of Pinnularia, before and
+      after division                                                    101
+
+  20             Transverse section of Nitzschia linearis (Ag.) Wm. Sm. 122
+
+  21             Transverse section (diagram) of Navicula                89
+
+  22             Transverse section (diagram) of Cymbella                60
+
+  23             Transverse section (diagram) of Amphora                 65
+
+
+
+[Illustration: PLATE 40]
+
+
+
+
+
+End of the Project Gutenberg EBook of The Diatomaceae of Philadelphia and
+Vicinity, by Charles Sumner Boyer
+
+*** END OF THIS PROJECT GUTENBERG EBOOK DIATOMACEAE ***
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+  <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
+  <link rel="coverpage" href="images/cover.jpg" />
+  <title>
+    Diatomaceae of Philadelphia
+  </title>
+
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+<pre>
+
+The Project Gutenberg EBook of The Diatomaceae of Philadelphia and Vicinity, by 
+Charles Sumner Boyer
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: The Diatomaceae of Philadelphia and Vicinity
+
+Author: Charles Sumner Boyer
+
+Release Date: January 3, 2014 [EBook #44569]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+*** START OF THIS PROJECT GUTENBERG EBOOK DIATOMACEAE ***
+
+
+
+
+Produced by Charlene Taylor, Bryan Ness, Keith Edkins and
+the Online Distributed Proofreading Team at
+http://www.pgdp.net (This file was produced from images
+generously made available by The Internet Archive)
+
+
+
+
+
+
+</pre>
+
+  <div class="ac w85 fcenter sp5">
+    <a href="images/frontispiece.jpg"><img style="width:100%" src="images/frontispiece.jpg"
+    alt="Duck Pond" title="Duck Pond"/></a>
+    <div class="smaller ac">
+      <p class="sp0">DUCK POND, CORNER OF FOURTH AND MARKET STREETS (ABOUT 1700)</p>
+    </div>
+  </div>
+
+  <p class="sp3 ac" style="margin-bottom:19.1ex;"><span class="xxx-larger">THE DIATOMACEÆ OF<br/>
+  PHILADELPHIA AND VICINITY</span></p>
+
+  <p class="ac" style="margin-bottom:0.3ex;">BY</p>
+
+  <p class="sp3 ac" style="margin-bottom:9ex;"><span class="x-larger">CHARLES S. BOYER, A.M.,
+  F.R.M.S.</span></p>
+
+  <p class="sp3 ac" style="margin-bottom:19.2ex;"><i>ILLUSTRATED WITH SEVEN HUNDRED<br/>
+  DRAWINGS BY THE AUTHOR</i></p>
+
+  <p class="ac" style="margin-bottom:0ex;"><span class="smaller">PRESS OF</span></p>
+
+  <p class="ac" style="margin-bottom:0.1ex;">J. B. LIPPINCOTT COMPANY</p>
+
+  <p class="ac" style="margin-bottom:0.1ex;"><span class="smaller">EAST WASHINGTON SQUARE
+  PHILADELPHIA</span></p>
+
+  <p class="sp5 ac" style="margin-bottom:9ex;"><span class="smaller">1916</span></p>
+
+  <h1 class="sp3 ac" style="margin-bottom:2ex;"><span class="x-larger">PREFACE</span></h1>
+
+  <p>The present contribution to the local flora is intended as an introduction to more extended
+  research.</p>
+
+  <p>The study is of advantage in relation to the life history of aquatic animals, the determination
+  of ocean currents, as proved by polar discoveries, the investigation of geological strata where
+  other fossil forms are absent, and the analysis of water supply; and, when we consider the
+  universal distribution of diatomaceæ in the earth, the water and even in the air and the enormous
+  deposits formed in past ages and still forming, we are able to realize the importance of a
+  knowledge of these complicated forms and their function of purification.</p>
+
+  <p>The absence of descriptive works of reference in available form in this country, the polyglot
+  confusion of authorities abroad and the amount of time, patience and skill required in obtaining,
+  preparing and examining specimens, render the study one of difficulty.</p>
+
+  <p>The bibliography is omitted, as it is understood by those who possess the works of reference,
+  and but few synonyms are given, having but little, except historical, value, especially when it is
+  considered that modern investigators have no access to many of the earlier collections, when any
+  of these exist.</p>
+
+  <p>So far as the marine forms are concerned, it is probable that nearly all occurring north of
+  Florida are here included, and the fresh-water species described represent a large proportion of
+  those found east of the Alleghanies. All of the figures are drawn to the same scale, a
+  magnification of eight hundred diameters, from specimens in my possession, nearly all of which
+  were found in or near Philadelphia.</p>
+
+  <p>If the work is of any value in inducing further investigation, I hope, in the words of Julien
+  Deby, that "those who follow my advice will find in the study of these wonderful little organisms
+  as much pleasure as I myself have found."</p>
+
+  <div class="poem sp5">
+    <p><span class="sc">The Author.</span></p>
+  </div>
+
+  <div><span class="pagenum" id="page5">{5}</span></div>
+
+  <h1 class="sp3 ac" style="margin-bottom:2ex;"><span class="x-larger">INTRODUCTION</span></h1>
+
+  <p>The Delaware River rises in the Western Catskill Mountains, flows southward for about three
+  hundred and seventy-five miles, and expands into Delaware Bay about sixty miles from the sea. Its
+  origin is among the Devonian and Carboniferous rocks, and in its course it passes through
+  Silurian, Triassic and Cretaceous formations, finally reaching the Cambrian and Laurentian beds.
+  It also drains regions of the glacial drift and beds which overlie overturned Miocene strata, and
+  are sometimes mixed with them. From the mountains, nearly four thousand feet high, to the Bay,
+  where the depth of water is not greater than seventy-five feet, the diatomaceous flora, from
+  Alpine cascades to the salt marshes of New Jersey, contains a larger number of species than any
+  other equal portion of the American coast.</p>
+
+  <p>The city of Philadelphia, about one hundred miles from the sea, lies at the junction of the
+  Schuylkill with the Delaware, and much of the land near the rivers, especially southward, is flat
+  and low, composed of recent alluvial deposits. In the central districts the ground is high, the
+  deep sub-soil being mostly a dry gravel resting upon gneiss and schist, although it is in part
+  composed of a bluish clay which was probably laid down in the bed of the ancient river before the
+  last period of the glacial drift. The blue clay was not all deposited at the same time, as in the
+  lower strata many marine forms are found which do not occur in the upper layers. This is notably
+  the case in a deposit obtained at Spreckel's Sugar Refinery and also at the east end of Walnut
+  Street Bridge, where a layer of blue clay occurs which is overlain by glacial drift. In other
+  parts of the city mixtures of blue clay with more recent deposits are found, including fresh-water
+  forms from numerous creeks and rivulets which traversed what is now the city proper, and
+  especially from the vicinity of Fourth and Market Streets, where there existed as late as the year
+  1700 a large pond known as the "Duck Pond" which was subject to tidal overflow from its outlet,
+  Dock Creek. The river water at Philadelphia is not noticeably brackish, although the tide extends
+  thirty miles above the city and, before the building of Fairmount Dam, to the Falls of the
+  Schuylkill. At certain times, when the river is low, the influx of tide water is sufficient to
+  produce an abundance of brackish water diatoms at Greenwich Point. The entire absence, however, at
+  present, of many of the marine forms obtained in dredgings in the Delaware opposite the city, as
+  at Smith's Island, now removed, and in certain well borings at Pavonia, Pensauken, Gloucester and
+  other places in New Jersey, where the depth reached the old blue clay, indicates conditions quite
+  different from those now prevalent. In the Bay itself comparatively few living species are found,
+  at least in any abundance.</p>
+
+  <p>In the study of local forms which follows, the district included may be considered as
+  circumscribed by the circumference of a circle having a radius of one hundred miles from
+  Philadelphia, containing the States of New Jersey and Delaware, the southeastern part of <span
+  class="pagenum" id="page6">{6}</span>Pennsylvania, a portion of Maryland on the south and
+  extending eastward to New York Bay and Long Island Sound as far as New Rochelle.</p>
+
+  <p>The greater number of fresh-water species described have been obtained from near the city along
+  the Darby, Crum, Ridley and Brandywine Creeks and from various places in New Jersey, including the
+  Pine Barren region of the southern part of the State. Numerous collections have been made in the
+  Schuylkill and the various reservoirs and along the Wissahickon, "where an Alpine gorge in
+  miniature of singular loveliness is to be found within the limits of a city." The fossil deposits
+  are from well borings near Camden, N. J., and from excavations in various parts of the city.</p>
+
+  <p>There appears to be no relation between the Miocene beds of the eastern coast and the deposits
+  here described, all of which have been formed later than the glacial period or in an interval
+  between two such periods. Apparently no diatoms grew during the glacial era, at least in
+  sufficient abundance to leave any perceptible traces of their existence. An examination of glacial
+  "flour" and clays from the Catskills shows an entire absence of these forms, and I have never
+  found them in the milky flow from the glaciers of the Alps nor in the constantly muddy streams in
+  certain of our Western States. The opacity of the water produces the same result as the absence of
+  light in the deep lakes of New England, where diatoms are found only on the stalks or roots of
+  water-plants near the shore, while in shallow ponds, such as the small lake near the summit of Mt.
+  Lafayette, the growth is abundant. Certain species will grow wherever there are moisture, light
+  and heat, but the greater number require the presence, in small amounts, of substances produced by
+  the decay of animal and vegetable life. An abundance of diatoms in fresh water is usually an
+  indication of its potability, while their entire absence in shallow water may be due to an excess
+  of bacteria.</p>
+
+  <p>The specimens from which the drawings are made have been collected by the author for many
+  years; in addition to possessing an almost complete library on the subject, he has had the
+  advantage of examining material obtained by the late Mr. Lewis Woolman and numerous slides
+  furnished by a number of friends, including Mr. John A. Shulze, Mr. Frank J. Keeley and Mr. T.
+  Chalkley Palmer, to whom I here take pleasure in expressing my thanks.</p>
+
+  <p>The difficulties of the study are well stated by Agardh in the following extract from the
+  preface to his Systema Algarum:</p>
+
+  <p>"Because, indeed, in this respect, no one will wonder whether in the distinction of species and
+  reference to synonyms we have, perchance, committed many errors. They have occurred and are bound
+  to occur, partly from the fact that one is not permitted to see the original specimens of all
+  authors; partly, because sometimes even the original specimens of these plants are erroneous;
+  partly, because the figures and descriptions of authors are often lacking and imperfect....</p>
+
+  <p>"There is added the difficulty of the study itself of these plants, their submerged habitat,
+  the minuteness of their structure, the rarity of their fruit, the change in the dried <span
+  class="pagenum" id="page7">{7}</span>plant, the impossibility of culture, the fallacies of
+  microscopical vision and the chaotic condition of Algology itself to-day."</p>
+
+  <p class="sp3">The words of Agardh, written in 1824, are almost as true to-day. The lack of
+  authentic specimens, which we hope will be remedied in time by the collections of the Smithsonian
+  Institute, numerous incorrectly labelled slides in amateur collections, the imperfections of
+  figures copied and recopied, without regard to relative size or correct references, and the
+  confusion in the attempts to harmonize different descriptions, deter the student at the outset.
+  The remaining difficulties mentioned by Agardh add, however, to the remarkable interest these
+  forms have always had, since no increase in optical perfection of the microscope serves to lessen
+  the mystery of their structure and mode of growth.</p>
+
+  <h2>CLASSIFICATION</h2>
+
+  <p>The few species of diatoms first discovered were included by Lyngbye, Dillwyn, and others in
+  the genus <i>Conferva</i>. In 1824, the species, increased to forty-eight, were separated by
+  Agardh into eight genera distinguished partly by their mode of growth. But little change was made
+  until Heiberg, in 1863, advocated the division into symmetrical and asymmetrical forms. Without
+  entering upon a general review of the later classifications, including Pfitzer's and Petit's
+  divisions according to the number and location of the chromatophores, or the arrangement of Prof.
+  H. L. Smith, because of the presence or absence of a raphe, or that of Mereschkowsky into motile
+  and immotile forms, the modification of all of these methods by Schuett is here adopted, varied in
+  accordance with certain monographs which appear to offer advantage.</p>
+
+  <p>It is customary, especially among writers who are familiar with other classes of plants, to
+  decry any classification of diatoms according to the markings of their siliceous envelopes. As,
+  however, one of the chief distinctions of the class is the possession of a more or less siliceous
+  and indestructible frustule, and as the cell and its contents are never seen except within the
+  valves, their variety forms the only available method of identification. The cell contents, owing
+  to the difficulty of observing their living condition, their continued change, their lack of
+  distinct variation and their entire absence in fossil forms, render their consideration as a
+  complete method of classification an impossibility. If, however, the cell contents can be brought
+  into relation with the markings of their siliceous envelope, it will be a consummation for which
+  the future student of these complicated forms ought to be grateful. That this result is one to be
+  expected may be inferred from the fact that the arrangement of protoplasmic masses in the interior
+  of the cell is coincident in some cases with markings on the valve, and the character of the
+  endochrome is assuming a certain value in accentuating the difference between such forms as
+  <i>Pleurosigma</i> and <i>Gyrosigma</i>, or in the resemblance between <i>Hantzschia</i> and
+  <i>Nitzschia</i>, or between <i>Surirella</i> and <i>Campylodiscus</i>. Mereschkowsky, however,
+  states that it is necessary to be careful in "establishing the relationship between diatoms based
+  on the resemblance of their chromatophores," <span class="pagenum" id="page8">{8}</span>and
+  further observes that in <i>Hantzschia amphioxys</i>, <i>Scoliotropis latestriata</i> and
+  <i>Achnanthes brevipes</i>, three widely separated forms, the chromatophores are essentially the
+  same.</p>
+
+  <p class="sp5">In one of the earliest classifications of diatoms, the individual cell received
+  less consideration than the nature of the filament or thallus in which many species occur in the
+  first stages of their growth. Those, however, which exist in colonies at first are, sooner or
+  later, broken up into separate frustules, either before or at the time of their maturity or
+  previous to conjugation, while very many species are never seen except in a free state. The union
+  of frustules, therefore, is of secondary importance and the group must be considered as
+  filamentous or unicellular algæ. Their relation to other algæ is not well determined. Among the
+  <i>Desmidiaceæ</i>, a family of the order <i>Conjugales</i>, of the class <i>Chlorophyceæ</i>, the
+  cells are in many forms divided by a constriction into symmetrical halves. The Conjugales are
+  starch forming, with walls of cellulose. In the Diatomaceæ the starch is replaced by oil globules,
+  while the walls of cellulose are more or less filled with a deposit of silica. The Conjugales,
+  however, reproduce by zygospores and usually contain pyrenoids, as may be seen in the parietal
+  chromatophores of <i>Spirogyra</i>. In the class <i>Heterokontæ</i> we have the reserve material
+  in the form of oil, instead of starch, but there are no pyrenoids. To this class belongs the order
+  <i>Confervaceæ</i>, in which the cells are unicellular or filamentous, and to which all of the
+  Diatomaceæ were referred. While, therefore, Diatomaceæ have a close affinity to the Desmidiaceæ
+  and to the Confervaceæ, the determination of their origin, one from another, or from a common
+  ancestral type, appears to be a matter of conjecture.</p>
+
+  <div><span class="pagenum" id="page9">{9}</span></div>
+
+  <h1 class="sp3 ac" style="margin-bottom:2ex;"><span class="x-larger">MORPHOLOGY AND
+  DEVELOPMENT</span></h1>
+
+  <h2>THE CELL</h2>
+
+  <p>The cell membrane is composed of two usually equal parts, each of which consists of a valve and
+  a girdle or zone formed of cellulose modified by silica deposited in an insoluble state from a
+  very dilute aqueous solution. The valves are more siliceous and robust than the girdle. Both are
+  in most species easily separable, or at least the bands of the girdle which may be more or less
+  closely fastened to the valves have a motion over each other permitting the cell to enlarge at
+  pleasure. The longitudinal diameter of the cell, or the distance between the centres of the two
+  valves, will vary according to the convexity of the valve and the age of the frustule which may be
+  often determined by the width or number of the girdle bands. These, owing to their diversity of
+  form and arrangement, will be further described under the generic diagnoses.</p>
+
+  <p>The siliceous cell-wall is covered on the outside by a layer of protoplasm called the
+  coleoderm. This layer may be quite thin and evident only when treated with fuchsin or Bismarck
+  brown, or it may be of considerable thickness. The cell contains the cytoplasma, protoplasm,
+  cell-sap, endochrome, pyrenoids, oil globules and nucleus, together with certain other less
+  understood bodies.</p>
+
+  <p>The Cytoplasma is a thin skin of colorless plasma covering the entire inner surface of the
+  cell. It is invisible in the living cell but is evident in plasmolysis. In long forms it is
+  thickened at the ends and is condensed at the plasma bridge which frequently connects the two
+  valves and divides the cell into two parts, each containing more or less protoplasm surrounding
+  the vacuole in which are found the cell-sap and certain granules. In some forms, as Meloseira, the
+  cytoplasma includes the entire mass of protoplasm.</p>
+
+  <p>The Endochrome is seen in the form of one or more bands or plates, of a yellowish or brownish
+  color, on the inner side of the valves or connective zone, or in granules or irregular masses,
+  more or less numerous, on the inner walls, or sometimes grouped near the centre. It consists of a
+  mixture of chlorophyll and diatomine which differ in their relative solubility in alcohol and in
+  their spectroscopic analyses. The color varies from green to a chocolate brown in proportion to
+  the amount of diatomine. So far as the function of the endochrome is concerned it does not appear
+  to differ from that of ordinary chlorophyll, absorbing, under the influence of light, the carbon,
+  and disengaging the oxygen of the carbonic anhydride in the water. Diatoms do not live in
+  absolutely pure or non-aërated water. The individual plates or granules of the endochrome are
+  called chromatophores. Their number and significance will be referred to in the description of
+  genera.</p>
+
+  <p><span class="sc">The Pyrenoids.</span>&mdash;In the chromatophores of many species are found
+  colorless, homogeneous bodies, strongly refractive, of various shapes, usually lenticular or
+  fusiform, which are known as Pyrenoids (Schmitz). They are scarcely evident in the living cell,
+  but are distinguished by the action of hæmatoxylin and other reagents. Flat forms occur in
+  Surirella and Pleurosigma, lens forms in Pinnularia, Stauroneis, Synedra, Fragilaria and
+  Nitzschia, while a spherical form is found in Cymbella cuspidata. The pyrenoids are always
+  imbedded in the chromatophore. Their growth is by division. Schmitz considers them a part of the
+  living chromatophore, and their substance as working material which in excess has become resolved
+  into the nature of a crystal which its form sometimes resembles. Comparisons are made between them
+  and crystalloids found in certain monocotyledons. The pyrenoid is evidently concerned in the
+  formation of the chromatophore, or in its division. Much of the conjecture, however, is due to the
+  behavior of pyrenoids in other plants.</p>
+
+  <div><span class="pagenum" id="page10">{10}</span></div>
+
+  <p><span class="sc">Oil Globules.</span>&mdash;It has been established by Pfitzer that starch and
+  sugar, as assimilation products, are replaced by oil in the cells of diatoms ("da bekannlich
+  Staerke und Zucker bei den Bacillariaceen nicht nachzuweisen sind"). The oil drops are more or
+  less numerous, of various sizes, and are found in the cytoplasma, the cell-sap, and sometimes the
+  chromatophores. Mereschkowsky describes certain globules as elæoplasts, which he divides into four
+  kinds according to their number and position. Whether all of these are oil globules is a question
+  not yet determined.</p>
+
+  <p>Other bodies, known as "Buetschli granules," or volutin, and described as "little blisters
+  filled with a tolerably robust refractive substance," are considered by Lauterborn to be a
+  nitrogen reserve store. They are found in the cytoplasma, or in the cell-sap, and can be fixed in
+  picric acid and stained in methylene blue.</p>
+
+  <p class="sp3"><span class="sc">Note.</span>&mdash;For a discussion of the morphology of diatoms
+  and a valuable résumé of the investigations of Buetschli, Karsten, Lauterborn, Mereschkowsky,
+  Mueller, Pfitzer, Schuett, and others, the student is referred to "Der Bau der Diatomzelle," by
+  Dr. Otto Heinzerling, in "Bibliotheca Botanica," 1908.</p>
+
+  <h2><span class="sc">Cell Division</span></h2>
+
+  <p>The growth of diatoms follows the usual method of cell division as described by Sachs (Text
+  Book of Botany, 2nd ed., p. 16): "The nucleus of a cell which is about to divide becomes broader,
+  assuming the form of a biconcave lens, and its nucleolus breaks up into irregular granules which
+  together with its other granular contents begin to form a nuclear disc in the equatorial plane. A
+  delicate striation is now apparent in what is becoming the long axis of the nucleus, at right
+  angles to the nuclear disc, and the characteristic nuclear spindle is gradually produced. The
+  nuclear disc splits into two halves lying side by side, each of which travels to the corresponding
+  pole of the nucleus; thus two nuclei are constituted which are connected by fibrillæ."</p>
+
+  <p>The cell-wall and the chromatophore bands divide, each nucleus passes to the centre, and two
+  new cells are formed. In the meantime, to permit of this division, the two siliceous valves
+  separate, the girdle bands slipping over each other, and opposite the larger or enclosing valve a
+  new valve is formed, the girdle band of which is seen later within the girdle of the mother valve.
+  Opposite the smaller valve of the original cell and adjoining the new valve, another valve is
+  formed which also produces a girdle within the girdle of the smaller valve. As a result of
+  division we have, therefore, the valves of the original, or mother cell, the two new valves and
+  four girdle bands. (Pl. <a href="#plate40"><b>40</b></a>, Figs. 18 and 19.)</p>
+
+  <p class="sp3">In the process of division, the continual formation of new valves, enclosed in the
+  older girdle bands, will naturally cause a reduction in the size of the frustule. While this
+  reduction, owing to the elasticity of the girdle, does not always occur, I believe, yet, in most
+  cases, the diameter is so reduced that a rejuvenescence of growth is required. This is caused by
+  the production of auxospores which may appear without conjugation. In this process, the beginning
+  of which, in certain species, may be noticed by the increase in the size of the girdle as in
+  reduplication, the two valves separate and within is formed a more or less spherical mass about
+  twice the size of the original frustule and which forms on its circumference two large and often
+  shapeless valves. These valves form others which assume the appearance of the original valves, but
+  larger, and proceed to grow in the usual way. The reduction in size of the frustule seldom
+  proceeds further than about half the size of the type form, so that, as a general rule, it may be
+  stated that diatoms are not often smaller than half the larger size.</p>
+
+  <h2><span class="sc">Reproduction</span></h2>
+
+  <p>The process of reproduction has been observed in many cases, but the conclusions reached are
+  somewhat at variance with each other. The auxospore formation is simply a <span class="pagenum"
+  id="page11">{11}</span>method of rejuvenescence. When, however, the auxospores are thrown off from
+  filamentous diatoms, it is probable that two may conjugate, their contents dividing each into two
+  daughter cells which unite into two zygospores. The usual method is the union of two frustules,
+  which, throwing off the old valves, coalesce into a single mass of protoplasm which produces an
+  auxospore, sometimes called a sporangial frustule. It is stated that in some cases two frustules
+  coalesce and produce two auxospores.</p>
+
+  <p>The existence of spores in diatoms is a much-disputed point. While they have never been seen,
+  the inference that they exist is very great, as otherwise it becomes difficult to understand the
+  sudden growth of species in localities and under conditions that seem to preclude the actual
+  presence of the living frustule. It is a matter of common observation that, in examining
+  collections of living forms, minute frustules or brownish globules appear to resemble larger
+  diatoms. In gatherings of Gomphonema, when many specimens are sessile on the same object, numerous
+  intermediate sizes, varying from minute globules to the type, are seen, yet not positively
+  demonstrable as the same.</p>
+
+  <p class="sp3">Conjugation, the formation of auxospores, and the actual process of cell division
+  are seldom seen, as they occur during the night or at least in darkness. It is advisable in order
+  to observe reduplication to obtain the material about midnight and place it in very dilute
+  alcohol. In filamentous forms, however, the cell division is easily observed at any time in its
+  various stages. By immersing in picric acid (saturated solution), transferring to very dilute
+  alcohol which is gradually increased in strength, and then passing through oil of cloves and
+  finally to the mounting medium, excellent preparations can be made. By staining with gold chloride
+  alone the nucleus is made apparent without further treatment.</p>
+
+  <h2><span class="sc">Evolution of Forms</span></h2>
+
+  <p class="sp3">It may be assumed that diatoms originated in the sea; to deny this requires
+  evidence of the existence of fresh-water species previous to the Miocene period which is entirely
+  marine. In those subject to fluctuations of the waves, as pelagic diatoms, their existence appears
+  to be contingent upon the methods by which the separate frustules can cohere. Various devices,
+  including hooks, spiral bundles, horns and processes exuding threads of plasma, exist for holding
+  together the frustules. When marine forms are found in quiet waters some of these devices, being
+  no longer of any value, cease to grow, although free swimming diatoms are rare. They either occur
+  in long chains or are stipitate or sessile. If it is further assumed that the fresh-water diatoms
+  are found in greater abundance in later periods, the action of running streams makes necessary the
+  provision of some means by which the species may continue to colonize. This may be recognized in
+  the occurrence of linear forms chiefly in streams. Circular forms, such as Cyclotella which have
+  no raphe, are found in quiet waters, such as pools or ditches, and never exist living in running
+  streams. Those forms only would be able to live in water having a more or less swift current under
+  one of three conditions: they must, as in Gomphonema, be adherent to surrounding objects by a
+  stipe; or be enclosed in a gelatinous tube, as in Hom&#x0153;ocladia; or have an independent
+  motion powerful enough to overcome the influence of the current. It is true that many forms with a
+  raphe have no apparent motion. In the case of Mastogloia provision is made in a gelatinous cushion
+  in which the frustules are preserved. In Cocconeis, with a true raphe in one valve only, in
+  Epithemia, with a partial raphe, or in certain Eunotiæ with a trace of one, we find species
+  evidently degenerate and parasitic. The long Synedræ, having only a median line, live in running
+  streams, since they are attached at one end to other algae. Forms with a true raphe appear to be
+  more highly developed, since they are able to seek locations favorable to growth. Given,
+  therefore, the structure of the valve, the habitat may be inferred.</p>
+
+  <div><span class="pagenum" id="page12">{12}</span></div>
+
+  <h2><span class="sc">The Motion of Diatoms</span></h2>
+
+  <p>The erratic backward and forward movement of certain diatoms, especially those of the
+  Naviculoid group, or the slow, rolling motion of Surirella, has been discussed in so many ways
+  without definite conclusions that a brief statement will be sufficient. Osmosis, the
+  am&#x0153;boid movement of the coleoderm, the protrusion of protoplasm or protoplasmic threads
+  through the raphe, the existence of actual organs of locomotion or cilia, and the lack of
+  synchronism in the chemical action occurring at the ends of the cell which is sometimes divided by
+  the plasma bridge, have been offered in explanation. The chief objection to the theory of cyclosis
+  appears to be that the resultant motion is so greatly in excess of the rotation of protoplasm in
+  the cell. More or less motion is observed in various kinds of free cells, but the movement of
+  diatoms is not evident in those without either a raphe or a keel upon which and apparently by
+  which the phenomena are produced.</p>
+
+  <p>Mr. T. Chalkley Palmer, in various articles in the Proceedings of the Delaware County Institute
+  of Science, especially in Vols. 1 and 3, gives the results of exhaustive experiments. "Nothing, it
+  would seem," he says, "could be more conclusive as to the essential sameness of the nature of
+  motion in monads and diatoms, than the fact that both monads and diatoms require oxygen in order
+  to perform motion, that they come to rest when oxygen becomes scarce, and that they resume their
+  motion when oxygen is again supplied."</p>
+
+  <p class="sp3">He also thinks "that the living substance of the cell, more or less deeply overlaid
+  with coleoderm substance of varying consistency, and itself assuming that degree of fluidity which
+  best meets the requirements of the situation, permeates the raphes, circulates in the keels, or in
+  some cases protrudes quite beyond the silica, and functions as the actual propulsive agent."</p>
+
+  <h2><span class="sc">The Function of Diatoms</span></h2>
+
+  <p>Of all forms of vegetation, the Diatomaceæ are, perhaps, the most ubiquitous. Where-ever a
+  sufficient amount of moisture, heat and light are found, they grow. It was during the Miocene
+  period that they first appeared, and, as marine forms, reached their greatest development, both as
+  to size and beauty of marking, while their prevalence throughout the world in enormous quantities
+  has been often mentioned. The Miocene beds of Richmond and Maryland continued over the Cretaceous
+  formations of New Jersey have outcropped in certain localities within our district, but are not
+  considered in this discussion.</p>
+
+  <p>The function of diatoms is not essentially different from that of other algæ in providing food
+  for aquatic animals, such as Salpæ and oysters, but it is, however, in other respects that they
+  are not only important but necessary factors in the preservation of life.</p>
+
+  <div class="poem">
+    <p style="margin-left:-0.40em">"Full nature swarms with life; one wondrous mass</p>
+    <p>Of animals, or atoms organized,</p>
+    <p>Waiting the vital breath, when parent heaven</p>
+    <p>Shall bid his spirit blow. The hoary fen,</p>
+    <p>In putrid streams, emits the living cloud</p>
+    <p>Of pestilence. Thro' subterranean cells</p>
+    <p>Where searching sunbeams scarce can find a way,</p>
+    <p>Earth animated heaves."</p>
+  </div>
+
+  <p class="sp5">I am not certain if Thomson fully understood the matter, but he has remarkably
+  described the facts. When "the vital breath" of returning spring animates the earth, the
+  "subterranean cells" of diatoms, the "atoms organized," through the liberation of vast quantities
+  of oxygen, immediately begin the purification of the "putrid streams." Were these streams not so
+  purified, the accumulation of animal and vegetable débris would eventually cause an enormous
+  bacterial growth fatal to animal life.</p>
+
+  <div><span class="pagenum" id="page13">{13}</span></div>
+
+  <h1 class="sp3 ac" style="margin-bottom:2ex;"><span class="x-larger">DIATOMACEÆ</span></h1>
+
+  <p class="sp4">Unicellular or filamentous. Cells either free, sessile, united in filaments,
+  immersed in a gelatinous envelope or in fronds composed of branching tubes; microscopic, enclosed
+  in a more or less siliceous envelope (frustule), composed of two parts (valves), usually connected
+  by an intervening band (zone or girdle). Cell contents include yellowish or brownish
+  chlorophyll-like bodies which occur in one or several bands (placcochromatic), or as variously
+  distributed granular masses (coccochromatic) lining the inner walls. Growth by ordinary cell
+  division or by auxospores; sexual multiplication by the formation of sporangia. Valves of two
+  kinds: (<i>a</i>) Those in which the markings or parts are more or less concentric (Centricæ);
+  (<i>b</i>) Those (Pennatæ) in which the parts are more or less symmetrically divided by a line
+  (pseudoraphe) or by a cleft (raphe).</p>
+
+  <h1 class="ac" style="margin-bottom:1.6ex;"><span class="larger">CENTRICÆ</span></h1>
+
+  <p>Valves without a dividing line or cleft; markings more or less radiate; transverse section of
+  frustule circular, polygonal, or elliptical, sometimes irregular.</p>
+
+  <p>Divided into four groups:</p>
+
+  <p>1. <i>Discoideæ.</i>&mdash;Frustules (cells) discoid; valves without horns or elevations
+  (sometimes with processes).</p>
+
+  <p>2. <i>Solenoideæ.</i>&mdash;Frustules with numerous girdle bands.</p>
+
+  <p>3. <i>Biddulphioideæ.</i>&mdash;Frustules box-like, <i>i. e.</i>, with the longitudinal axis
+  greater than in the Discoideæ. Valves with two or more angles, elevations or horns.</p>
+
+  <p>4. <i>Rutilarioideæ.</i>&mdash;Valves as if naviculoid, but with irregular or radial
+  structure.</p>
+
+  <p class="sp4">Groups 2 and 4 are not included in our description. No. 2 contains plankton genera
+  only, while No. 4 consists of genera not yet found in this locality.</p>
+
+  <h2>DISCOIDEÆ</h2>
+
+  <p>1. <i>Coscinodisceæ.</i>&mdash;Valve not divided by rays or costæ into sectors; puncta
+  sometimes radiate; ocelli or processes absent.</p>
+
+  <p>2. <i>Actinodisceæ.</i>&mdash;Valve with radial striæ divided into sectors: ocelli and
+  processes absent.</p>
+
+  <p class="sp4">3. <i>Eupodisceæ.</i>&mdash;Valve disc-shaped with mammiform processes or one or
+  more ocelli.</p>
+
+  <h3>1. COSCINODISCEÆ</h3>
+
+  <p>(<i>a</i>) <i>Meloseirinæ.</i>&mdash;Frustules short, in chains.</p>
+
+  <p class="sp4">(<i>b</i>) <i>Coscinodiscinæ.</i>&mdash;Frustules disc form, usually single, rarely
+  in short chains.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">(<i>a</i>) MELOSEIRINÆ</span></p>
+
+  <p>1. <i>Meloseira.</i>&mdash;Valve punctate, with a constriction or furrow between edge of valve
+  and girdle.</p>
+
+  <p>2. <i>Gaillonella.</i>&mdash;Valve punctate, with a circular collar or crest near edge of
+  valve.</p>
+
+  <p>3. <i>Lysigonium.</i>&mdash;Valve punctate, neither keeled nor constricted.</p>
+
+  <p>4. <i>Hyalodiscus.</i>&mdash;Valve punctate in the centre; border with decussating radial
+  lines.</p>
+
+  <p>5. <i>Stephanopyxis.</i>&mdash;Border of valve with a crown of thorns; valve areolate.</p>
+
+  <p class="sp3">6. <i>Pyxidicula.</i>&mdash;Valve areolate, with a border of spines.</p>
+
+  <div><span class="pagenum" id="page14">{14}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Meloseira Ag.</span> (1824), em.
+  <span class="sc">De Toni</span> (1892)</h4>
+
+  <p class="ac">(melos, a limb or member, and seira, a chain)</p>
+
+  <p>Frustules globose, ellipsoidal or cylindrical, concatenate, closely joined together. Valve
+  either simply punctate or punctate and areolate. A constriction of the cell-wall, forming a furrow
+  between the edge of the valve and the girdle, is more or less evident.</p>
+
+  <p>The genus Meloseira constituted by Agardh has been variously modified by Kuetzing, Thwaites,
+  Wm. Smith, Van Heurck, De Toni, and others. In Systema Algarum Agardh included certain species of
+  Conferva, of Lyngbye, Dillwyn and others, and limited his genus to frustules more or less globose
+  (fila articulata ad genicula constricta), although in his Conspectus Criticus (p. 64), he modifies
+  the description (fila teretia articulata, articulis diametro æqualibus vel longioribus) to include
+  M. varians. As, however, Lysigonium Link, Gaillonella Bory, and other genera enlarged by Ehrenberg
+  and Kuetzing, came to be included under Meloseira, Thwaites suggested the division of the genus
+  into two: Orthosira, in which the frustules are not convex at the ends and Aulacosira in which no
+  central line is apparent but with two distinct sulci. Wm. Smith adopts the genus Orthosira but
+  rejects Aulacosira, including all forms under the former genus and Meloseira, suggesting that
+  differences "exist in the formation of the sporangia" of the two genera. M. varians and M.
+  crenulata appear to form auxospores or sporangial frustules in different ways, as will be noticed
+  hereafter.</p>
+
+  <p class="sp3">As, however, the present state of our knowledge is so limited and as much confusion
+  would result in further changing the nomenclature, I shall adopt, for the most part, the division
+  made by De Toni, separating Gaillonella and Lysigonium and employing the name Meloseira as
+  emendated in Sylloge Algarum, although, as stated, it omits the species of Agardh. That a further
+  division may be necessary is indicated by the differences existing between the Orthosira forms and
+  the others.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANALYSIS OF SPECIES</span></p>
+
+  <table class="sp2 mc w50" title="Species of Meloseira" summary="Species of Meloseira">
+    <tr class="pb05">
+      <td colspan="2">Frustules cylindrical and lengthened:</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Valves with two distinct furrows; granules small</td>
+      <td class="vbm">distans</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Valves with coarse granules</td>
+      <td class="vbm">granulata</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Valves denticulate on the margin</td>
+      <td class="vbm">crenulata</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Valves denticulate and constricted</td>
+      <td class="vbm">roeseana</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Valves with row of large puncta on the girdle side</td>
+      <td class="vbm">undulata</td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="2">Frustules cylindrical and compressed:</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Valves punctate and areolate</td>
+      <td class="vbm">sulcata</td>
+    </tr>
+  </table>
+
+  <p class="sp3">The chromatophores consist of circular and compressed or irregular flat granules
+  which lie along the wall of the cell.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MELOSEIRA DISTANS (EHR.)
+  KUETZ.</span></p>
+
+  <p>Frustules cylindrical, slender, with two furrows, one on each side of the suture; valve in zone
+  view with fine puncta in longitudinal rows; puncta in valve view scattered. L. 7-10 µ.</p>
+
+  <p><i>Meloseira nivalis</i> Wm. Sm.</p>
+
+  <p><i>Coscinodiscus minor</i> Wm. Sm.</p>
+
+  <p>Fresh water. Fossil in New England deposits.</p>
+
+  <p>Pl. <a href="#plate1"><b>1</b></a>, Figs. 8 and 9.</p>
+
+  <p class="sp3"><span class="sc">Note.</span>&mdash;In all species of Meloseira, as well as
+  Gaillonella and Lysigonium, the frustules are so closely coherent that when the filaments are
+  broken entire frustules are less frequently found than a union of two valves of contiguous
+  frustules.</p>
+
+  <div><span class="pagenum" id="page15">{15}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MELOSEIRA GRANULATA (EHR.)
+  RALFS</span></p>
+
+  <p>Frustules cylindrical, robust, 5-18 µ in diam., with large granules in longitudinal, sometimes
+  spiral, lines, variable in size and arrangement in the same filament. Valve in valve view with
+  scattered puncta. Variable in relative width and length, passing to M. crenulata.</p>
+
+  <p><i>Gaillonella granulata</i> Ehr.</p>
+
+  <p><i>Orthosira punctata</i> Wm. Sm.</p>
+
+  <p>Fresh water. Fossil at Coldspring, L. I.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MELOSEIRA CRENULATA (EHR.)
+  KUETZ.</span></p>
+
+  <p>Frustules cylindrical, with furrows on each side of the suture, 10-20 µ in diam.; puncta in
+  longitudinal rows. Margins of valves denticulate at the junction of the frustules; valves with
+  puncta scattered at the centre, radiate at the circumference.</p>
+
+  <p>Common in fresh water; quite variable in size.</p>
+
+  <p><i>Gaillonella crenulata</i> Ehr.</p>
+
+  <p><i>Orthosira orichalcea</i> Wm. Sm. in part; not Conferva orichalcea. Mertens or Gaillonella
+  aurichalcea Ehr. and Bailey.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Figs. 1 and 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MELOSEIRA ROESEANA
+  RAB.</span></p>
+
+  <p>Frustules cylindrical, constricted toward each end, with coarse, longitudinal striæ; valve
+  convex, striæ punctate, radiating, with several large granules at the centre. Connective zone with
+  longitudinal rows of fine puncta. Diam. 12-45 µ.</p>
+
+  <p><i>Orthosira spinosa</i> Grev.</p>
+
+  <p>Fresh water. Media, Pa. (Palmer); not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Figs. 5 and 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MELOSEIRA ROESEANA VAR.
+  EPIDENDRON (EHR.) GRUN.</span></p>
+
+  <p>Frustules denticulate at the margin; valve with coarse granules at the centre from which
+  radiate lines of fine puncta.</p>
+
+  <p>Wet rocks of the Wissahickon.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Figs. 3 and 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MELOSEIRA UNDULATA (EHR.)
+  KUETZ.</span></p>
+
+  <p>Frustules single or in twos, usually broader than long, constricted near the margin. Valve with
+  six to twelve internal projections forming with the outline of the constriction of the valve a
+  polygonal figure within the circumference. Surface of the valve with radiating lines of puncta
+  disappearing toward the centre, at which are numerous coarse puncta.</p>
+
+  <p><i>Meloseira gowenii</i> A. Schmidt.</p>
+
+  <p>Blue clay of Philadelphia, especially common at Twelfth and Market Sts.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Figs. 15, 16, 17.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MELOSEIRA SULCATA
+  KUETZ.</span></p>
+
+  <p>Frustules quite robust, with diam. several times the length, deeply furrowed at the margin,
+  areolate and punctate. Valve with radiating striæ disappearing toward the centre, and with a
+  double row of cells near the margin, the outer one having the appearance of a crown of teeth.</p>
+
+  <p><i>Gaillonella sulcata</i> Ehr.</p>
+
+  <p><i>Paralia sulcata</i> (Ehr.) Cleve.</p>
+
+  <p><i>Paralia marina</i> Heib.</p>
+
+  <div><span class="pagenum" id="page16">{16}</span></div>
+
+  <p>Marine and brackish. Common in all parts of the world, and fossil in the Miocene. The
+  Philadelphia form is the var. genuina Grun.</p>
+
+  <p>Pl. <a href="#plate1"><b>1</b></a>, Figs. 11 and 12.</p>
+
+  <p>In a gathering from Media of Meloseira crenulata (Palmer leg.), occasional filaments are
+  noticed with much longer and narrower frustules which become enlarged in the middle and are seen
+  to contain inner frustules in the process of still further division, as shown in Fig. 2, Pl. <a
+  href="#plate38"><b>38</b></a>.</p>
+
+  <p class="sp3">Meloseira dickei Thwaites shows internal box-like cells placed one within the
+  other, which were supposed by Thwaites to be a method of reproduction. Wm. Smith doubts this, but
+  is unable to offer any explanation. In the present form the mode of reduplication is that usually
+  found in filamentous forms, but in this case the presence of perfect frustules enclosing others in
+  the process of still further division has been heretofore unfamiliar to me. The swelling in the
+  middle appears to indicate that not all filamentous diatoms are reduced in size by subdivision. In
+  outline the valve is like that of a "truncated cone," as described by Petit in referring to
+  Gaillonella granulata var. bambusina Petit (Diat. Nouv. et Rares, Jour. de Micrographie,
+  1890).</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Gaillonella Bory de St.
+  Vincent</span> (1823)</h4>
+
+  <p class="ac">(named after Gaillon, a botanist of Dieppe)</p>
+
+  <p>Frustules ellipsoidal, united in long filaments, usually found in pairs; each valve is
+  furnished with a circular collar or crest extending at right angles to the convex edge. Valve
+  hyaline at the centre from near which radiate lines of fine puncta, 18-20 in 10 µ.</p>
+
+  <p class="sp3"><span class="sc">Note.</span>&mdash;The original names of both Meloseira and
+  Gaillonella are retained, as there is no good reason for contracting the Greek diphthong in the
+  first, and the second is the correct spelling.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GAILLONELLA NUMMULOIDES (DILLW.)
+  BORY</span></p>
+
+  <p>Frustules as in the generic diagnosis. Diam. 30 µ.</p>
+
+  <p><i>Conferva nummuloides</i> Dillwyn (Brit. Confervæ, p. 45, Sup. Pl. B).</p>
+
+  <p><i>Meloseira nummuloides</i> Ag.</p>
+
+  <p>Heiberg and O'Meara assign this species to <i>Lysigonium moniliforme</i> (Muell.) Link, which
+  is not keeled. While Dillwyn's and Lyngbye's figures do not show the keel, it is probable from
+  their descriptions that the angular outline produced by the keel was noticed.</p>
+
+  <p>Marine or brackish. Coast of New Jersey; Hudson River (Bail.).</p>
+
+  <p>Pl. <a href="#plate1"><b>1</b></a>, Figs. 13 and 14.</p>
+
+  <p class="sp3"><i>Gaillonella moniliformis</i> of Bailey is this form, as he describes it as
+  having "two minute projections of the delicate transverse ridges seen near the ends of the two
+  globules belonging to a joint." (Amer. Jour. Science, 1842, p. 89, Pl. 2, Fig. 3.)</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Lysigonium Link</span> (1820)</h4>
+
+  <p class="ac">(luo, to loose, and gonu, a joint)</p>
+
+  <p class="sp3">Frustules globose, concatenate; valve simply punctate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LYSIGONIUM MONILIFORME (MUELL.)
+  LINK</span></p>
+
+  <p>Frustules usually in twos, not keeled; valve with puncta in longitudinal lines, the puncta of
+  the enveloping zone larger and in transverse rows. L. 25-40 µ (De Toni).</p>
+
+  <p><i>Conferva moniliformis</i> Mueller (1783).</p>
+
+  <div><span class="pagenum" id="page17">{17}</span></div>
+
+  <p><i>Conferva nummuloides</i> Eng. Bot. pl., 2287, not Dillwyn.</p>
+
+  <p><i>Meloseira borreri</i> Grev.</p>
+
+  <p><i>Lysigonium nummuloides</i> (Lyngb., Kuetz.) O'Meara = <i>Gaillonella nummuloides</i>
+  (Dillw.) Bory. See O'Meara, p. 248.</p>
+
+  <p>Marine and brackish. Long Island Sound and coast of New Jersey.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LYSIGONIUM VARIANS (AG.) DE
+  TONI</span></p>
+
+  <p>Frustules cylindrical, in long filaments, slightly constricted on each side of the suture;
+  puncta in oblique rows in zone view. Valves 15-35 µ in diam. (De Toni), sub-plane, with fine
+  puncta in lines radiating from the centre. Under medium magnification the frustules appear smooth.
+  Very variable in size.</p>
+
+  <p><i>Meloseira varians</i> Ag.</p>
+
+  <p>Fresh water. Common in ditches and springs.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Figs. 18 and 19.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Hyalodiscus Ehr.</span> (1845)</h4>
+
+  <p class="ac">(hyalos, transparent, and discus, a disc)</p>
+
+  <p class="sp3">Frustules spheroidal; valve with a flattened, irregularly punctate umbilicus from
+  which proceed radiating or decussating lines of fine puncta.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANALYSIS OF SPECIES</span></p>
+
+  <table class="sp3 mc w50" title="Species of Hyalodiscus" summary="Species of Hyalodiscus">
+    <tr class="pb05">
+      <td class="itp05">Valves divided into sectors</td>
+      <td class="vbm">stelliger</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Valves not divided but interrupted by short dark lines at intervals</td>
+      <td class="vbm">radiatus</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Valves with very fine puncta</td>
+      <td class="vbm">scoticus</td>
+    </tr>
+  </table>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HYALODISCUS STELLIGER
+  BAIL.</span></p>
+
+  <p>Valve with puncta in oblique decussating rows which, by reason of the difference in obliquity,
+  form numerous sectors. Umbilicus irregular, with scattered, coarse puncta. Margin wide,
+  striated.</p>
+
+  <p><i>Podosira maculata</i> Wm. Sm.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Fig. 22.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HYALODISCUS RADIATUS VAR. ARCTICA
+  GRUN.</span></p>
+
+  <p>Valve with radiating puncta from a rather small umbilicus, the rays interspersed with short,
+  dark lines, having the appearance of spines, at irregular intervals. Margin broad, striated.</p>
+
+  <p><i>Pyxidicula radiata</i> O'Meara.</p>
+
+  <p>The Philadelphia form corresponds exactly to Grunow's variety which has closer puncta than the
+  type form.</p>
+
+  <p>Blue clay. Rather rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate1"><b>1</b></a>, Fig. 21.</p>
+
+  <div><span class="pagenum" id="page18">{18}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HYALODISCUS SCOTICUS (KUETZ.)
+  GRUN.</span></p>
+
+  <p>Valve small, with puncta about 24 in 10 µ, appearing hyaline.</p>
+
+  <p>De Toni remarks that it resembles a small form of H. subtilis which occurs north and south of
+  our limits and is yet likely to be recorded.</p>
+
+  <p><i>Cyclotella scotica</i> Kuetz.</p>
+
+  <p><i>Podosira hormoides</i> Wm. Sm.</p>
+
+  <p>Blue clay. Not rare.</p>
+
+  <p>Pl. <a href="#plate1"><b>1</b></a>, Fig. 20.</p>
+
+  <p class="sp3">Endochrome in the form of four flaps or patches bound together about a common
+  pyrenoid. In H. subtilis numerous rod-shaped chromatophores lie in a row and are not bound in the
+  centre (Mereschkowsky).</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Stephanopyxis Ehr.</span> (1844) em.
+  <span class="sc">Grun.</span> (1884)</h4>
+
+  <p class="ac">(stephanos, a crown, and pyxis, a kind of vase or box)</p>
+
+  <p>Frustules ellipsoidal, concatenate; valves tumid, of unequal convexity, coarsely areolate, the
+  cells in rows parallel to the longitudinal axis, not radiate, with stray spines or teeth placed
+  concentrically more or less near the margin.</p>
+
+  <p class="sp3">According to Karsten the chromatophores are round or angular discs which lie near
+  the connective zone.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STEPHANOPYXIS TURRIS (GREV.)
+  RALFS</span></p>
+
+  <p>Valve cylindrical, with a crown of stout spines less than the diameter of the valve near the
+  margin. Cells hexagonal, about 2 in 10 µ, sometimes punctate. The valve having the greater
+  convexity has the larger spines, though usually less of them.</p>
+
+  <p><i>Creswellia turris</i> Grev. (Gregory, Diat. of the Clyde, T. R. S. E., vol. 21, part 4, p.
+  66.)</p>
+
+  <p><i>Stephanopyxis appendiculata</i> Ehr.?</p>
+
+  <p>Creswellia is incorrectly based, as stated by Ralfs, on the concatenation of the valves which
+  was not noticed by Ehrenberg in the fossil forms. It had been suggested by Kuetzing in Systema
+  Algarum (p. 126).</p>
+
+  <p>Blue clay. Port Penn and Smith's Island.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Figs. 1 and 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STEPHANOPYXIS CORONA (EHR.)
+  GRUN.</span></p>
+
+  <p>Valve larger than in turris, sub-globose, coarsely areolate cells, 4-5 in 10 µ. One valve
+  furnished with a crown of teeth shaped like the letter <span class="sans"><b>T</b></span> and
+  united at the top into a ring above the margin of the valve; the other valve with long spines more
+  or less concentrically arranged.</p>
+
+  <p>Blue clay. Not common. Fossil in the Nottingham deposit.</p>
+
+  <p>Pl. <a href="#plate2"><b>2</b></a>, Fig. 3.</p>
+
+  <p class="sp3"><span class="sc">Note.</span>&mdash;The diatomaceous deposit, so often called
+  "Bermuda" or "Bermuda tripoli," especially by foreign writers, is in reality the Miocene stratum
+  extending for miles along the Patuxent River near the village of Nottingham, Md. The author is
+  perfectly familiar with the location, having made large collections there. The mistake in the name
+  is due to the fact that Prof. Bailey received material from Mr. Tuomey marked "Bermuda Hundred,"
+  which is located near Petersburg, Va. Attempts have been made to find material there and while
+  there is an earth containing Miocene diatoms at Petersburg, it does not exactly correspond to the
+  material sent to Ehrenberg by Bailey, who was in doubt as to the locality. The Bermuda Islands are
+  of coral formation and have no deposits of diatomaceous earth.</p>
+
+  <div><span class="pagenum" id="page19">{19}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Pyxidicula Ehr.</span> (1833)</h4>
+
+  <p class="ac">(dim. of pyxis, a box)</p>
+
+  <p class="sp3">Frustules globular, solitary or in short fasciæ. Valve more or less hemispherical,
+  areolate, destitute of spines.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PYXIDICULA CRUCIATA
+  EHR.</span></p>
+
+  <p>Valve hemispherical, with large, hexagonal cells. An inner stratum is finely punctate.</p>
+
+  <p>Blue clay. Walnut St. Bridge. Rare.</p>
+
+  <p>Pl. <a href="#plate38"><b>38</b></a>, Fig. 8.</p>
+
+  <p>This form is not usually described as having punctate areolæ, but it does not apparently differ
+  from other forms of Pyxidicula of Ehrenberg as described by Kuetzing (Species Algarum, pp. 21-23),
+  including <i>P. areolata</i>. In fact, it differs from Stephanopyxis, which is also sometimes
+  punctate, only in the absence of spines. In fossil deposits the absence of an easily detached
+  stratum is not significant. The difference, except in size, between it and <i>P. mediterranea</i>
+  Grun. (V. H. S., Pl. 95, Figs. 15 and 16), I am unable to determine.</p>
+
+  <p class="sp4">Although many species of Meloseira are fresh-water, the habitat of the group
+  Meloseirinæ is, in general, marine. It more nearly coincides in structure and development with
+  other algæ not diatomaceous, the siliceous envelope constituting its most distinctive feature. As
+  we proceed in the classification, the structure both of the frustule and contents becomes more
+  complicated.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">(<i>b</i>)
+  COSCINODISCINÆ</span></p>
+
+  <p>1. <i>Cyclotella.</i>&mdash;Valve with two concentric divisions of different structure, one a
+  wide border and the other a central surface.</p>
+
+  <p class="sp3">2. <i>Coscinodiscus.</i>&mdash;Valve areolate or punctate, with a narrow border of
+  the same structure.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Cyclotella Kuetz.</span> (1833)</h4>
+
+  <p class="ac">(cyclos, a circle)</p>
+
+  <p>Frustules single or geminate, cylindrical, short, in zone view rectangular or with undulating
+  sides. Valve usually with smooth or punctate striæ, centre sometimes bullose, smooth, or with
+  granules scattered or radiating.</p>
+
+  <p class="sp3">Chromatophores numerous along the valves (Pfitzer).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA STRIATA (KUETZ.)
+  GRUN.</span></p>
+
+  <p>Valve 30-80 µ in diam., with coarse striæ, 7-12 in 10 µ, centre coarsely punctate and
+  bullose.</p>
+
+  <p><i>Coscinodiscus striatus</i> Kuetz.</p>
+
+  <p><i>Cyclotella dallasiana</i> Wm. Sm.</p>
+
+  <p>Common in the blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA MENEGHINIANA
+  KUETZ.</span></p>
+
+  <p>Frustule in zone view rectangular, undulated; valve, 10-20 µ in diam., marginal striæ robust
+  and transversely punctate, centre radiately punctate.</p>
+
+  <p><i>Cyclotella kuetzingiana</i> Wm. Sm. (not Thwaites).</p>
+
+  <p>Crum Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 8.</p>
+
+  <div><span class="pagenum" id="page20">{20}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA MENEGHINIANA, VAR.
+  STELLIGERA CL. AND GRUN.</span></p>
+
+  <p>Differs from the type in the coarse radiating lines at the centre.</p>
+
+  <p>Broomall Lake, Media.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA MENEGHINIANA, VAR.
+  STELLULIFERA CL. AND GRUN.</span></p>
+
+  <p>As in type but with the central rays granulate.</p>
+
+  <p>Broomall Lake, Media.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA STYLORUM (BR.?) V.
+  H.</span></p>
+
+  <p>Margin striated, the alternate striæ thickened near the border, producing an appearance of
+  subquadrate cells. Centre faintly granulate, the outer border of which is encircled by 10-12
+  puncta, each of which is surrounded by a small hyaline space.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Van Heurck gives this form doubtfully as a variety of <i>striata</i>, while De Toni makes it
+  synonymous with it. Van Heurck's figure is not that of Brightwell, but as the specimen above
+  described is, I believe, exactly the same as Van Heurck's, I retain his name.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA COMTA (EHR.)
+  KUETZ.</span></p>
+
+  <p>Valve with marginal striæ well marked, each third or fourth costa more robust than the others.
+  Central part finely striated, the striæ punctate, radiating.</p>
+
+  <p>Fresh water.</p>
+
+  <p>Pl. <a href="#plate2"><b>2</b></a>, Fig. 7.</p>
+
+  <p class="sp3">The form here figured is probably the variety <i>radiosa</i> Grun. and is from a
+  New England specimen. It is quite likely to occur in this locality.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA OPERCULATA (AG.)
+  KUETZ.</span></p>
+
+  <p>Frustules in zone view undulated. Angles rounded. Marginal costæ alternating with minute
+  spines; centre nearly smooth, depressed, convex or flexuose.</p>
+
+  <p>Fresh water.</p>
+
+  <p>Pl. <a href="#plate2"><b>2</b></a>, Figs. 5 and 6.</p>
+
+  <p class="sp3">The figure is drawn from a specimen from Boston, Mass., H. L. Smith Type Slide No.
+  107, marked equivalent to <i>C. minutula</i> Wm. Sm.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYCLOTELLA ANTIQUA WM.
+  SM.</span></p>
+
+  <p>Marginal costæ alternating with thick puncta; centre finely granulate with subtriangular
+  elevations. Frustules in zone view rectangular.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate2"><b>2</b></a>, Fig. 11.</p>
+
+  <p>The form corresponds to the original specimens of Wm. Smith in the deposit of Stavenger,
+  Norway.</p>
+
+  <p class="sp3">The genus Cyclotella comprises about seventy specific names, many of which may be
+  referred to other genera, while some of Ehrenberg's are incapable of verification on account of
+  the small size of the figures and the lack of sufficient description. About half of the forms are
+  marine. The fresh-water species are usually found living in more or less stagnant water or in
+  pools contaminated with drainage, being an exception to the general rule that diatoms are more
+  abundant in water free from deleterious matter.</p>
+
+  <div><span class="pagenum" id="page21">{21}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Coscinodiscus Ehr.</span> (1838)</h4>
+
+  <p class="ac">(coscinon, a sieve, and discus)</p>
+
+  <p>Frustules solitary, cylindrical, compressed; valve circular or elliptical; surface flat or
+  sometimes convex near the border; markings more or less angular, radiating, sometimes fasciculate;
+  border usually well defined. Central space, if present, hyaline, sometimes surrounded with a
+  rosette of large cells.</p>
+
+  <p>Chromatophores round, angular or irregular discs usually without pyrenoids (Karsten).</p>
+
+  <p>Rattray's classification is here followed, so far as it refers to our species.</p>
+
+  <p><i>Excentrici.</i>&mdash;Valves circular; central space absent; markings angular, in oblique,
+  decussating rows.</p>
+
+  <p><i>Lineati.</i>&mdash;Central space absent; markings angular, oblique decussating rows
+  straight.</p>
+
+  <p><i>Fasciculati.</i>&mdash;Markings fasciculate, or sometimes only near the border.</p>
+
+  <p><i>Radiati.</i>&mdash;Markings rounded or angular, more or less radiate.</p>
+
+  <p class="sp3"><i>Elaborati.</i>&mdash;Valves elliptical, markings rounded.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EXCENTRICI</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS EXCENTRICUS
+  EHR.</span></p>
+
+  <p>Valve with a hyaline excentric space from which proceed, usually in six directions, rows of
+  polygonal markings decreasing toward the narrow, coarsely striated border, the rows appearing
+  convex toward the centre. Apiculi at unequal distances apart. Quite variable in size.</p>
+
+  <p>Common in the blue clay and along the coast.</p>
+
+  <p>Pl. <a href="#plate2"><b>2</b></a>, Figs. 14 and 20.</p>
+
+  <p class="sp3">Fig. 20 is probably var. <i>perpusilla</i> Grun. (Diat. Fr. Jos. L., Pl. 4 (D),
+  Fig. 7).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LINEATI</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS LINEATUS
+  EHR.</span></p>
+
+  <p>Valve circular, markings hexagonal, cells in parallel rows. Border narrow, cellular.</p>
+
+  <p>Blue clay and Atlantic coast. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate3"><b>3</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FASCICULATI</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS NITIDUS
+  GREG.</span></p>
+
+  <p>Valve flat, markings rounded, distant, radiate, decreasing toward the border which is coarsely
+  striate. Quite variable in size and in the distance between the markings.</p>
+
+  <p>Blue clay and Atlantic coast. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS NITIDULUS
+  GRUN.</span></p>
+
+  <p>Valve usually not quite circular; markings smaller than in nitidus and fasciculate near the
+  border.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate2"><b>2</b></a>, Fig. 19.</p>
+
+  <p class="sp3">Various intermediate forms between nitidus and nitidulus occur.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS SUBTILIS
+  EHR.</span></p>
+
+  <p>Markings polygonal, irregular at the centre, but forming numerous fasciculi radiating <span
+  class="pagenum" id="page22">{22}</span>toward the border, the rows parallel to the central row of
+  each fasciculus. Border narrow with fine striæ; apiculi often present between the fasciculi.</p>
+
+  <p>Blue clay and along the coast. Very common in the water supply of Philadelphia and Camden,
+  where the diameter seldom exceeds 40 µ and the markings on the semi-radius are 10 in 10 µ.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 17.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS DENARIUS
+  SCHMIDT</span></p>
+
+  <p>Markings larger than in C. subtilis, equal, forming usually ten fasciculi, each beginning near
+  the semi-radius and containing ten parallel rows of granules.</p>
+
+  <p>Common in the blue clay and sparingly along the coast.</p>
+
+  <p>Pl. <a href="#plate2"><b>2</b></a>, Fig. 13.</p>
+
+  <p class="sp3">Forms are found intermediate between C. subtilis and C. denarius, as shown in Fig.
+  15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS POLYACANTHUS
+  GRUN.</span></p>
+
+  <p>Markings angular, 10 in 10 µ, decreasing toward the border, fasciculate. Apiculi large, twelve
+  or more, usually inserted at the middle of each fasciculus, and extending into the interior of the
+  cell. The apiculi in outline resemble the heads of horse-shoe nails, and are seen with difficulty
+  except when the valve is examined from the inner side. Border narrow, striated. Diam. 70 µ.</p>
+
+  <p>Pensauken, N. J., artesian well.</p>
+
+  <p>Pl. <a href="#plate38"><b>38</b></a>, Fig. 5.</p>
+
+  <p class="sp3">Rattray's description of <i>C. polyacanthus</i> var. <i>intermedia</i> Grun., from
+  Cape Wankarema, Siberia, gives the diam. as 60 µ, and there are about 7 markings by actual count
+  in 10 µ in Grunow's figure (Diat. Fr. Jos. Land, Pl. 3 (C), Fig. 25). The apiculi are more
+  numerous, but there appears to be little doubt of the general similarity. The Philadelphia form is
+  abundant in the Pensauken well deposit at a depth of 33 ft. The apiculi become quite distinct in
+  slides stained with silver nitrate by Mr. F. J. Keeley; they are distinct from small apiculi
+  sometimes evident between the fasciculi. The specimens in the Pensauken deposit are mingled with
+  other forms which cannot be distinguished from <i>C. subtilis</i>. Whether the two are identical,
+  I am unable to determine. Rattray (Rev. Cos., p. 47) refers to H. L. Smith's Type Slide No. 100,
+  from rice-field mud, Savannah, Ga., as <i>C. subtilis</i>. In Smith's slide, in my possession, a
+  number of the forms show faint outlines of the large apiculi and are otherwise exactly like C.
+  polyacanthus.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RADIATI</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS VELATUS
+  EHR.</span></p>
+
+  <p>Markings angular, decreasing slightly toward the coarsely striated border, covered with fine
+  puncta.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate3"><b>3</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS MARGINATUS
+  EHR.</span></p>
+
+  <p>Markings rounded, large, decreasing toward the broad border, which is coarsely marked with
+  distant striæ. The cells are punctate.</p>
+
+  <p>Common in the blue clay.</p>
+
+  <p>Pl. <a href="#plate3"><b>3</b></a>, Fig. 9.</p>
+
+  <p class="sp3">In the fossil forms the puncta are not evident, hence the species is usually
+  described as not punctate.</p>
+
+  <div><span class="pagenum" id="page23">{23}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS RADIATUS
+  EHR.</span></p>
+
+  <p>Markings polygonal, slightly decreasing toward the border where they are much smaller; border
+  well marked, striate. Quite variable in size.</p>
+
+  <p>Common in the blue clay and along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate3"><b>3</b></a>, Fig. 11. Fig. 1 is probably a smaller form.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS
+  SUBAULACODISCOIDALIS RATTR.</span></p>
+
+  <p>Markings small, decreasing toward the border in somewhat fasciculate rows. About one-third the
+  distance from the border are five (Rattray finds six) well-marked apiculi somewhat resembling
+  those of Aulacodiscus. Border narrow, hyaline.</p>
+
+  <p>Rare in the lower stratum of the blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate3"><b>3</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS ARGUS
+  EHR.</span></p>
+
+  <p>Markings angular with central dots, increasing from the centre toward the border, where they
+  are smaller.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate3"><b>3</b></a>, Fig. 7 (a small form).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS BIANGULATUS
+  SCHMIDT</span></p>
+
+  <p>Central space and rosette absent, markings large, angular, not punctate, with large central
+  papillæ, decreasing toward the border. Border wide, coarsely marked with rows of granules, and
+  with two indentations on the inner side distant from each other about two-thirds of the
+  diameter.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate3"><b>3</b></a>, Fig. 3.</p>
+
+  <p class="sp3">Distinguished from Coscinodiscus asteromphalus var. omphalantha Grun., which also
+  has two constrictions, by the absence of punctate markings.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS ASTEROMPHALUS
+  EHR.</span></p>
+
+  <p>Central space small, surrounded by a rosette of large polygonal cells from which radiate
+  hexagonal cells, increasing about half way toward the border and then slightly decreasing. Cells
+  punctate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate2"><b>2</b></a>, Fig. 16; Pl. <a href="#plate40"><b>40</b></a>,
+  Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS ASTEROMPHALUS VAR.
+  OMPHALANTHA (EHR.) GRUN.</span></p>
+
+  <p>Central space absent, rosette evident. Markings 2½ in 10 µ, somewhat smaller near the rosette
+  and decreasing near the border, which is constricted in two places, as in C. biangulatus.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate38"><b>38</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS OCULUS-IRIDIS
+  EHR.</span></p>
+
+  <p>Central space and rosette distinct; markings polygonal, not punctate, with large papillæ,
+  smaller near the rosette, increasing toward the semi-radius, and then decreasing to the striated
+  border which is comparatively narrow.</p>
+
+  <p>Blue clay and Atlantic coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate3"><b>3</b></a>, Fig. 10.</p>
+
+  <div><span class="pagenum" id="page24">{24}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ELABORATI</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COSCINODISCUS LEWISIANUS
+  GREV.</span></p>
+
+  <p>Valves elliptical, major axis a little more than twice the minor. From a point, usually near
+  one side, radiate rows of granules in lines nearly parallel to the major axis. Border broad, with
+  distinct striæ.</p>
+
+  <p>Great Sedge Island, N. J. (artesian well), and in outcrops later than the Miocene, where it is
+  usually found.</p>
+
+  <p class="sp4">Pl. <a href="#plate3"><b>3</b></a>, Fig. 5.</p>
+
+  <h3>2. ACTINODISCEÆ</h3>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINOPTYCHINÆ</span></p>
+
+  <p>Valves divided into sectors alternately elevated and depressed.</p>
+
+  <p>(1) <i>Actinoptychus.</i>&mdash;Sectors plane.</p>
+
+  <p class="sp3">(2) <i>Polymyxus.</i>&mdash;Sectors convex.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Actinoptychus Ehr.</span> (1839) em.
+  V. H. (1890)</h4>
+
+  <p class="ac">(actis, a ray, and ptyx, a fold)</p>
+
+  <p class="sp3">Frustule cylindrical, less in length than the diameter, in zone view undulated.
+  Valve divided into six or more sectors alternately raised and depressed, areolate and punctate,
+  varying in the alternate divisions. The areolation is confined to the outer layer of the valve
+  while the punctation is usually on an inner valve often found detached. Processes on the border,
+  three or more. Umbilicus circular or angular, hyaline.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANALYSIS OF SPECIES</span></p>
+
+  <table class="sp3 mc w50" title="Species of Actinoptychus" summary="Species of Actinoptychus">
+    <tr class="pb05">
+      <td class="itp05">Sectors, six</td>
+      <td class="vbm">undulatus</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Sectors, eight or more, cellular</td>
+      <td class="vbm">heliopelta</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Sectors, fourteen, punctate</td>
+      <td class="vbm">vulgaris</td>
+    </tr>
+  </table>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINOPTYCHUS UNDULATUS (KUETZ.)
+  RALFS</span></p>
+
+  <p>Valve areolate and punctate in quincunx, divided into six equal sectors, alternately elevated
+  or depressed, their areolations appearing different. Margin well defined. Umbilicus smooth,
+  hexagonal. Processes three, sometimes six, inserted within the margin of each alternate division.
+  Very variable in size and appearance.</p>
+
+  <p>This is the Actinocyclus of Bailey, figured and described in Amer. Jour. Science, 1842, p. 93,
+  Pl. 2, Fig. 11, but not named. Kuetzing describes and names it and refers to Bailey.</p>
+
+  <p><i>Actinoptychus omphalopelta</i> Ehr.</p>
+
+  <p><i>Actinoptychus cellulosa</i> Ehr., H. L. Smith Sp. Typ., 384.</p>
+
+  <p>Quite common in marine and brackish water and in the blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate4"><b>4</b></a>, Figs. 1, 2, 4 and 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINOPTYCHUS VULGARIS VAR.
+  INTERRUPTA N. VAR.</span></p>
+
+  <p>Valve with fourteen sectors, the alternate ones divided by a smooth lanceolate space for about
+  one-half the radius, forming with the smooth, circular umbilicus a seven pointed star. The sectors
+  thus divided have coarser puncta in quincunx than the other sectors, ending in a smooth area near
+  the margin, and also larger black puncta scattered from the centre to the semi-radius.</p>
+
+  <p>Near A. vulgaris var. neogradensis Pant.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate4"><b>4</b></a>, Fig. 5.</p>
+
+  <div><span class="pagenum" id="page25">{25}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINOPTYCHUS HELIOPELTA GRUN.
+  VAR.?</span></p>
+
+  <p>Valve circular, sectors, eight, umbilicus circular, without rays; border wide, cellular, with
+  distinct rays. Inserted at a distance within the inner edge of the border are large processes, one
+  on each of four alternate sectors, and two on each of the others. The sectors are cellulate and
+  punctate.</p>
+
+  <p>Near A. heliopelta var. versicolor Brun., which, however, in the specimen in my collection from
+  Atlantic City (artesian well), has a greater number of processes and they are situated on the edge
+  of the border.</p>
+
+  <p>Outcrop at Buckshutem, N. J. Rare.</p>
+
+  <p>Pl. <a href="#plate4"><b>4</b></a>, Fig. 3.</p>
+
+  <p class="sp3">It has been quite well determined, I think, that the typical forms of A. heliopelta
+  occur at the base of the Miocene. At Rock Hall, Md., on the eastern shore of Chesapeake Bay, at a
+  depth of from 21 to 130 ft., and at Wildwood, N. J., at a depth of from 78 to 179 ft.,
+  diatomaceous beds occur considered by Mr. Lewis Woolman (Geol. Surv. of N. J., 1898, pp. 116-121)
+  "as synchronous in age," the former being deposited in the Delaware River Delta and the latter in
+  the Chesapeake in post-miocene times. In each of these beds a small form of A. heliopelta is
+  rarely found. The material at Buckshutem is post-miocene, and the form here figured shows a marked
+  variation from the Miocene species and a gradual approach toward A. undulatus.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Polymyxus L. W. Bail.</span>
+  (1855)</h4>
+
+  <p class="sp3">Valve circular, usually divided into fourteen sectors which are on the same plane
+  at the centre, but the alternate ones are elevated into mammillated projections terminated by
+  small processes on the margin. Zone view rectangular with undulations subconical, terminated by
+  the processes.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">POLYMYXUS CORONALIS L. W.
+  BAIL.</span></p>
+
+  <p>Central space hyaline, rounded or slightly stellate, from which radiate rows of fine puncta in
+  quincunx, shown in the figure only on the alternate elevations, the depressed interspaces being
+  out of focus. The mammillæ are stated by Bailey to vary from six to ten.</p>
+
+  <p>Very rare in the blue clay (Walnut St. Bridge). Occurs also in the Wildwood deposit (Bull.
+  Torrey Bot. Club, 1895, p. 261).</p>
+
+  <p class="sp4">Pl. <a href="#plate4"><b>4</b></a>, Fig. 7, and Pl. <a href="#plate5"><b>5</b></a>,
+  Fig. 2.</p>
+
+  <h3>3. EUPODISCEÆ</h3>
+
+  <p class="sp3"><i>Aulacodiscinæ.</i>&mdash;Valves with mammiform elevations near the border
+  surmounted by nipple-like processes.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AULACODISCUS&mdash;THE ONLY GENUS
+  AS ABOVE</span></p>
+
+  <p><i>Eupodiscinæ.</i>&mdash;Valves with ocelli.</p>
+
+  <p>(1) <i>Actinocyclus.</i>&mdash;Valve with one small ocellus; striæ radial.</p>
+
+  <p>(2) <i>Eupodiscus.</i>&mdash;Valve with one or more ocelli; striæ not radial.</p>
+
+  <p>(3) <i>Auliscus.</i>&mdash;Valve with large, elevated ocelli. Central area hyaline. Markings
+  granular and costate.</p>
+
+  <p class="sp3">(4) <i>Pseudauliscus.</i>&mdash;Valve with radiating granules. No central
+  space.</p>
+
+  <div><span class="pagenum" id="page26">{26}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Aulacodiscus Ehr.</span> (1844) em.
+  <span class="sc">Rattr.</span> (1888)</h4>
+
+  <p class="ac">(aulax, a furrow, and discus)</p>
+
+  <p>Valve usually circular, plane or with an elevated zone, frequently inflated beneath the
+  processes; central space irregular or rounded, sometimes absent; markings granular, radial,
+  sometimes in a reticulum.</p>
+
+  <p class="sp3">The genus comprises more than one hundred species most of which are fossil, and is
+  represented in this locality by a single form, <i>A. argus</i>, included by Rattray in his section
+  "Retiformes," distinguished by the presence of a reticulum.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AULACODISCUS ARGUS (EHR.)
+  SCHMIDT</span></p>
+
+  <p>Frustule in zone view elliptical. Valve circular, 125-190 µ in diam., closely covered with two
+  kinds of markings, one, a mesh of large, radiating, angular cells, the outer plate, and the other,
+  radiating rows of circular granules with hyaline spaces intervening and closer near the border,
+  forming the inner plate which can occasionally be seen detached. Central space absent. The walls
+  of the angular cells are crossed with fine lines and are probably composed of granules compressed
+  so closely as to produce partial opacity, the depth of which depends in a measure not only on the
+  superposition of the two plates, but on the relative closeness and thickness of the cell-walls. In
+  a fully-developed specimen the effect is to produce more or less triangular cells containing three
+  or four granules. In some cases the opacity is so great as to render detail invisible.</p>
+
+  <p>In the figure the valve is supposed to be divided into three sectors, illustrating at "a" the
+  lower plate, at "c" the combination of the upper and lower plates, and in the other sector the
+  cellular mesh of the upper plate. Processes, usually three, quite robust and inserted at from
+  one-fourth to one-fifth the length of the radius from the border which is striated on the inner
+  side. A form with four processes is found in the lower blue clay.</p>
+
+  <p><i>Tripodiscus argus</i> Ehr.</p>
+
+  <p><i>Eupodiscus argus</i> (Ehr.) Wm. Sm.</p>
+
+  <p>Not uncommon in the blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate4"><b>4</b></a>, Fig. 8.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Actinocyclus Ehr.</span> (1837)</h4>
+
+  <p class="ac">(actis, a ray, and cyclos)</p>
+
+  <p>Valve circular or elliptical; surface flat at the centre, sloping toward the border. Central
+  space usually evident, rounded or irregular. Markings rounded, granular, punctiform, in radial, or
+  nearly radial, rows, sometimes fasciculate. A nodule, more or less evident, is found near the
+  border which is usually striate.</p>
+
+  <p class="sp3">Chromatophores round discs or granules.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANALYSIS OF SPECIES</span></p>
+
+  <table class="sp2 mc w50" title="Species of Actinocyclus" summary="Species of Actinocyclus">
+    <tr class="pb05">
+      <td class="itp05">Valve circular, rows radial, hyaline lines at the border</td>
+      <td class="vbm">barkleyi</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Valve circular, rows fasciculate</td>
+      <td class="vbm">moniliformis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Valve elliptical</td>
+      <td class="vbm">ellipticus</td>
+    </tr>
+  </table>
+
+  <p class="sp3">The nodule is generally supposed to be a thickening of the cell-wall, and, in the
+  opinion of Rattray, a projection outward, but "whether there may not be at the same time a slight
+  inward protuberance is difficult to determine," though, as a rule, he seems to "think there is
+  not."</p>
+
+  <div><span class="pagenum" id="page27">{27}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINOCYCLUS BARKLEYI VAR.
+  AGGREGATA RATTR.</span></p>
+
+  <p>Surface flat from centre to semi-radius. Central space irregular, sometimes with a few
+  scattered granules. Markings round with central dots distinct, about 7 at the centre, decreasing
+  in straight radial rows to 12 in 10 µ at the border, where they form moniliform striæ. Border
+  narrow with striæ about 16 in 10 µ. Hyaline interspaces at the origin of the shorter rows, but not
+  at equal intervals. At the border, linear hyaline spaces occur at somewhat irregular intervals
+  between the moniliform striæ owing to the termination of certain radial rows before they reach the
+  circumference. Nodule small, from one-seventh to one-fourth the radius from the border.</p>
+
+  <p>According to Rattray the distinction between A. ralfsii and A. barkleyi is partly in the
+  absence of the zone arrangement of the hyaline spaces in the latter, and to the slight differences
+  in the number of granules. The variety aggregata differs from the type form of barkleyi mainly in
+  the distance of the nodule from the border. I have specimens from the blue clay material at Walnut
+  St. Bridge, and from Smith's Island, in which the distance from the border in one case is, as
+  stated above, quite different from that in the other. In specimens from Morris Cove, Conn., the
+  locality referred to by Rattray, variations occur.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate6"><b>6</b></a>, Fig. 1.</p>
+
+  <p class="sp3">In the figure the subulate hyaline spaces at the border are, in some instances,
+  wider than usual.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINOCYCLUS MONILIFORMIS
+  RALFS</span></p>
+
+  <p>Surface flat, from centre to about five-sixths of the radius. Central space rounded, with one
+  or more granules. Markings, 8 in 10 µ, round, in radial rows, fasciculate, the oblique transverse
+  rows irregular, very slightly decreasing until near the edge of the flattened zone, and then
+  suddenly decreasing and appearing as decussating lines oblique to the border. Apiculi distinct,
+  interfasciculate within the border. Nodule quite evident, surrounded by a rather wide irregular
+  hyaline space on the margin of the flattened zone in the middle of the fasciculus. Border wide,
+  with striæ about 20 in 10 µ.</p>
+
+  <p>Blue clay. Port Penn. Not common.</p>
+
+  <p>Pl. <a href="#plate6"><b>6</b></a>, Fig. 2.</p>
+
+  <p>Equivalent to Actinocyclus ehrenbergii, H. L. S. Type Slide 10.</p>
+
+  <p class="sp3">In a valve from Port Penn, Delaware Bay, two nodules occur nearly opposite each
+  other.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINOCYCLUS ELLIPTICUS VAR.
+  DELAWARENSIS N. VAR.</span></p>
+
+  <p>Valve rhombic-elliptical. Markings somewhat angular, 6 in 10 µ at the centre where they are
+  sub-concentric, thence decreasing in lines radiating more or less toward the border, where they
+  suddenly become punctiform, striæ about 20 in 10 µ. Border equal to one-fifth the radius. A nodule
+  is found on the inner side of the border. Apiculi apparently absent.</p>
+
+  <p>The markings are larger than in the Richmond forms which are associated by Rattray with
+  Actinocyclus ellipticus Grun. The form corresponds closely to Witt's Cestodiscus ovalis var.?
+  (Witt, Polierschief. von Archangelsk-Kurojedowo, Pl. 8, Fig. 2), except as to the border. It does
+  not answer to Van Heurck's figure or any other.</p>
+
+  <p>Blue clay. Very rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate3"><b>3</b></a>, Fig. 6.</p>
+
+  <div><span class="pagenum" id="page28">{28}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Eupodiscus Ehr.</span> (1844)</h4>
+
+  <p class="ac">(eu, well, pous, a foot, and discus)</p>
+
+  <p class="sp3">Valve circular, 45-117 µ in diam. (De Toni). Central space absent, surface plane
+  with angular cells. At the border short, circular processes or ocelli.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUPODISCUS RADIATUS
+  BAIL.</span></p>
+
+  <p>Valve with radiating hexagonal cells, sometimes slightly curved toward the large ocelli
+  inserted near the border which are hyaline at the centre. Border wide, coarsely striate.</p>
+
+  <p>The number of ocelli heretofore recorded is four. Specimens with five processes are found in
+  the artesian well at St. Augustine, Fla., and in material at Twelfth and Brandywine Sts. Mr. Hugo
+  Bilgram has discovered valves with three and six ocelli.</p>
+
+  <p>Not common in the blue clay, but abundant along the southern coast of the Atlantic states and
+  the Gulf of Mexico.</p>
+
+  <p>Not Eupodiscus radiatus Wm. Sm, which is Biddulphia smithii (Ralfs) V. H.</p>
+
+  <p class="sp3">Pl. <a href="#plate5"><b>5</b></a>, Fig. 3.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Auliscus Ehr.</span> (1843)</h4>
+
+  <p class="ac">(aulax, a furrow, referring to the grooves in certain species, according to De Toni,
+  but preferably from auliscos, a small reed, referring to the processes?)</p>
+
+  <p>Frustule cylindrical; zone with longitudinal rows of fine puncta. Valve circular or elliptical,
+  plane except near the processes; central area hyaline, usually circular. Markings of two kinds,
+  granules radiating or scattered and radiating, costate lines, prominent or indistinct. Processes,
+  two or three, large, short, cylindrical, with hyaline surface, near the ends of the major axis in
+  a line oblique to it.</p>
+
+  <p>Auliscus is divided by Rattray into fourteen sections, defined chiefly by the character and
+  arrangement of the markings. About eighty species are described, but as many of the forms are
+  fossil, occuring in the Miocene of California, Oamaru and elsewhere, and as so few species are
+  found in this locality, I shall refer but briefly to this division.</p>
+
+  <table class="sp2 mc w50" title="Sections of Auliscus" summary="Sections of Auliscus">
+    <tr class="pb05">
+      <td class="itp05"><i>Striolati.</i>&mdash;No transverse median areas, striæ inconspicuous</td>
+      <td class="vbm">punctatus</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05"><i>Lineolati.</i>&mdash;Markings distinct, pruinose, interrupted</td>
+      <td class="vbm">pruinosus</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05"><i>Costati.</i>&mdash;Transverse median areas usually distinct, markings
+      continuous, costate</td>
+      <td class="vbm">sculptus<br/>
+      cælatus</td>
+    </tr>
+  </table>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AULISCUS PUNCTATUS
+  BAIL.</span></p>
+
+  <p>Valve broadly elliptical, or suborbicular, covered with delicate interrupted striæ radiating in
+  sinuous lines to the circumference, more evident on the transverse median area; puncta 3 in 10 µ,
+  grouped into a rounded area on each side of the median line, elsewhere scattered. Central space
+  rounded, processes two, large, suborbicular.</p>
+
+  <p>Port Penn, Delaware River. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate5"><b>5</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AULISCUS PRUINOSUS
+  BAIL.</span></p>
+
+  <p>Valve elliptical, with distinct, interrupted, pruinose, irregular markings diverging in curved
+  lines toward the circumference in the median part and converging toward the processes,
+  interspersed with numerous darker markings having the appearance of apiculi. Central space nearly
+  circular, sometimes with several granules. Processes large near the ends of the major axis and not
+  oblique to it, or scarcely so, the edges with a crenulate border.</p>
+
+  <p>Blue clay. Rather rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate5"><b>5</b></a>, Fig. 8.</p>
+
+  <div><span class="pagenum" id="page29">{29}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AULISCUS SCULPTUS (WM. SM.)
+  RALFS</span></p>
+
+  <p>Valve elliptical or subcircular, median areas distinct, rounded, circumscribed by coarse
+  distant costæ radiating near the border where they are more evident, and converging toward the
+  processes. Central space rounded, sometimes indefinite. Processes, two, circular.</p>
+
+  <p>Typical specimens show wide, coarse, distant costæ, but, in some cases, the median areas are
+  indistinctly outlined.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate5"><b>5</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AULISCUS CÆLATUS BAIL.</span></p>
+
+  <p>Valve elliptical or subcircular, with radiating costæ, more evident around the median areas and
+  at the border, converging toward the processes, with intermediate punctate radiating lines.
+  Central space rounded or irregular. Processes circular.</p>
+
+  <p>A. sculptus has coarser costæ and the interspaces are hyaline, or apparently so, while in A.
+  cælatus the punctate striæ between the costæ are more evident.</p>
+
+  <p>Blue clay. Not uncommon.</p>
+
+  <p>Pl. <a href="#plate5"><b>5</b></a>, Fig. 4.</p>
+
+  <p class="sp3">Fig. 7 is a small, indefinite form intermediate between A. sculptus and A. cælatus.
+  The numerous variations in this genus make it difficult to satisfactorily differentiate the
+  species. The size of the four above described varies from 40 to 150 µ.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Pseudauliscus A. S.</span> (1875)
+  <span class="sc">and Leuduger-Fortmorel</span> (1879)</h4>
+
+  <p>Valve circular or subcircular, nearly flat or depressed at the centre. Central space not
+  evident. Processes circular, with narrow border, near the circumference. Border narrow, striated.
+  Markings granular, radiating, sometimes interspersed with striæ and apiculi.</p>
+
+  <p class="sp3">Differs from Auliscus chiefly in the absence of a central space and costæ.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PSEUDAULISCUS RADIATUS (BAIL.)
+  RATTR.</span></p>
+
+  <p>Valve circular, or nearly so, flat. Central area with scattered granules radiating and
+  increasing in size outward in diverging rows toward the border which is coarsely striated.
+  Processes, two, circular. Two small apiculi are inserted at about one-fifth the radius from the
+  border near the ends of the minor axis.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Pl. <a href="#plate5"><b>5</b></a>, Fig. 9.</p>
+
+  <p class="sp3">The apiculi are not always figured. They appear in a number of specimens from the
+  Miocene of Maryland, Atlantic City, Harvey Cedars and Newbern.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PSEUDAULISCUS SPINOSUS
+  (CHRISTIAN) RATTR.</span></p>
+
+  <p>Valve subcircular or slightly quadrangular, depressed at the centre and rising to an elevated
+  zone near the border, the two zones separated by a distinct line. The inner zone indistinctly
+  reticulate with fine puncta radiating from the centre and apiculi at intervals. The outer zone
+  with smaller apiculi surrounding the inner zone and with intermingled rows of fine puncta and
+  interrupted diverging striæ. Near each end of the minor axis is a rather long, robust spine
+  inserted at one-fourth the radius from the border which is narrow and striated. Processes
+  circular, close to the circumference.</p>
+
+  <p><i>Auliscus spinosus</i> Christian.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Pl. <a href="#plate5"><b>5</b></a>, Fig. 10.</p>
+
+  <p class="sp4">The genus is named by Schmidt, described by Leuduger-Fortmorel and emendated by
+  Rattray.</p>
+
+  <div><span class="pagenum" id="page30">{30}</span></div>
+
+  <h2>BIDDULPHIOIDEÆ</h2>
+
+  <h3>BIDDULPHIEÆ</h3>
+
+  <p>(<i>a</i>) <i>Triceratiinæ.</i>&mdash;Frustule cylindrical or prismatic, with three or more
+  sides.</p>
+
+  <p>(<i>b</i>) <i>Biddulphiinæ.</i>&mdash;Frustule cylindroid; valve with ends elevated into round
+  processes or long horns.</p>
+
+  <p>(<i>c</i>) <i>Anauleæ.</i>&mdash;Valve elliptical, lunate or triangular, with internal
+  septa.</p>
+
+  <p class="sp4">(<i>d</i>) <i>Euodieæ.</i>&mdash;Frustule cuneate in zone view; valve lunate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">(<i>a</i>)
+  TRICERATIINÆ</span></p>
+
+  <p>(1) <i>Ditylum.</i>&mdash;Frustule imperfectly siliceous. Zone with numerous divisions. Valve
+  with central spine.</p>
+
+  <p class="sp3">(2) <i>Trinacria.</i>&mdash;Processes with sharp spines.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Ditylum Bail.</span> (1861)</h4>
+
+  <p class="ac">(dis, two, and tyle, a swelling, referring to the outline of the frustule)</p>
+
+  <p class="sp3">Frustule quadrangular, convex at the ends. Valve triangular, with undulating sides,
+  the angles ending in a sharp point surmounted by a bristle. Surface of valve convex at centre from
+  which projects a long stout spine.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DITYLUM INTRICATUM (WEST)
+  GRUN.</span></p>
+
+  <p>Valve with the angles separated from the central part by lines imitating septa. Surface with
+  radiating lines of fine puncta.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Pl. <a href="#plate6"><b>6</b></a>, Fig. 4.</p>
+
+  <p>Detached valves only have been found in the blue clay. The form is regarded as but slightly
+  siliceous and, therefore, the zone or girdle not being found in the fossil deposits, I am unable
+  to illustrate it from material in the vicinity. On Plate <a href="#plate38"><b>38</b></a>, Figs. 6
+  and 7, I have sketched the zone and valve views of specimens found recently at Vera Cruz and
+  labelled by H. L. Smith Triceratum intricatum West. I can find no difference between the recent
+  and fossil forms of the valves. The zone is covered with fine puncta in quincunx, not visible
+  under ordinary illumination.</p>
+
+  <p class="sp3">The form as figured in Plate <a href="#plate6"><b>6</b></a> corresponds to the
+  figure of Lithodesmium undulatum Ehr. in Van Heurck, and West, in describing the Triceratium
+  undulatum Wm. Sm. (figured as T. striolatum), thought that his T. intricatum was distinct from
+  Ehrenberg's form on the ground that the latter came from the "Bermuda" (Nottingham) earth and must
+  be strongly siliceous. Lithodesmium is characterized by the envelopment of the frustules by a
+  cellular membrane which does not appear, evidently, in Ditylum. D. brightwellii is distinguished
+  by its crown of spines on the margin; otherwise it closely resembles D. intricatum.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Trinacria Heib.</span> (1863)</h4>
+
+  <p class="ac">(treis, three, and acra, a point)</p>
+
+  <p class="sp3">Valve triangular, angles elevated into spines. Cells at the margin large.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TRINACRIA PILEOLUS (EHR.)
+  GRUN.</span></p>
+
+  <p>Valve with concave sides. Surface concave with unequal punctiform and scattered markings with
+  central dots. Cells at the margin large, rounded. At the angles, which vary in elevation, a few
+  puncta are seen.</p>
+
+  <p><i>Triceratium pileolus</i> Ehr.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p class="sp4">Pl. <a href="#plate6"><b>6</b></a>, Fig. 9.</p>
+
+  <div><span class="pagenum" id="page31">{31}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">(<i>b</i>)
+  BIDDULPHIINÆ</span></p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Biddulphia Gray</span> (1831) em.
+  <span class="sc">Van Heurck</span> (1885)</h4>
+
+  <p class="ac">(a genus, constituted from Conferva biddulphiana of the English Botany, named after
+  a Miss Biddulph)</p>
+
+  <p class="sp3">Frustule prismatic or subcylindrical, concatenate, filamentous, or in zig-zag, or,
+  as usually found, free. Zone well developed. Valve triangular, polygonal, elliptic or subcircular,
+  convex, more or less elevated at the angles into processes or horns. Markings cellular or
+  punctate. Chromatophores, small plates of various forms.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">KEY TO THE SPECIES</span></p>
+
+  <table class="sp3 mc w50" title="Species of Biddulphia" summary="Species of Biddulphia">
+    <tr class="pb05">
+      <td class="itp05">Valves costate</td>
+      <td class="vbm">biddulphiana</td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="2">Valves not costate:</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Markings cellular, angles elevated into horns</td>
+      <td class="vbm">favus</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="hid">Markings cellular,</span> angles not elevated</td>
+      <td class="vbm">antediluviana</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Markings punctate, angles with subconical processes and long spines</td>
+      <td class="vbm">granulata</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="gap" style="width:2em">&nbsp;</span>spines short</td>
+      <td class="vbm">rhombus</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="gap" style="width:2em">&nbsp;</span>spines minute</td>
+      <td class="vbm">smithii</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="gap" style="width:2em">&nbsp;</span>processes truncate, valve
+      elliptical</td>
+      <td class="vbm">turgida</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="gap" style="width:2em">&nbsp;</span><span class="hid">processes
+      truncate,</span> valve orbicular</td>
+      <td class="vbm">lævis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="gap" style="width:2em">&nbsp;</span>processes absent, valve
+      divided by irregular lines</td>
+      <td class="vbm">alternans</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="gap" style="width:2em">&nbsp;</span>not so divided</td>
+      <td class="vbm">reticulum</td>
+    </tr>
+  </table>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA BIDDULPHIANA
+  (SMITH)</span></p>
+
+  <p>Frustule quadrangular with convex ends and rounded angles. Valve elliptical with undulated
+  sides, divided by septa into three or more sections. Processes large, rounded, globular or
+  subconical. Zone varying in width. Surface with rounded reticulations in longitudinal and
+  transverse rows, except at the centre where they are concentric and smaller.</p>
+
+  <p><i>Conferva biddulphiana</i> Smith (English Botany, 1807, Pl. 1762, upper figures).</p>
+
+  <p><i>Diatoma biddulphianum</i> Ag.</p>
+
+  <p><i>Biddulphia pulchella</i> Gray.</p>
+
+  <p>Blue clay. Hoboken Tunnel. Along the coast.</p>
+
+  <p>Pl. <a href="#plate7"><b>7</b></a>, Figs. 1, 2, 3, and 4.</p>
+
+  <p class="sp3">Quite variable in size and number of septate divisions. Fig. 3 is an unusual form
+  with narrow zone, having but one row of large reticulations, evidently a young frustule.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA FAVUS (EHR.) V.
+  H.</span></p>
+
+  <p>Frustule quadrangular, elevated at the angles into subconical processes oblique to the
+  longitudinal axis. Valve triangular or quadrangular, plane, of two layers, the outer layer
+  composed of large hexagonal cells in rows parallel to the sides, the inner of small puncta
+  radiating from the centre. Zone punctate in quincunx, never found open.</p>
+
+  <p><i>Triceratium favus</i> Ehr.</p>
+
+  <p>Blue clay. Common along the coast.</p>
+
+  <p>The quadrangular form occurs only southward.</p>
+
+  <p class="sp3">Pl. <a href="#plate6"><b>6</b></a>, Fig. 6. At "a" a cell showing the lower
+  punctate layer. Pl. <a href="#plate40"><b>40</b></a>, Fig. 16, a transverse section of a portion
+  of the valve showing the cellular structure and the punctated lower stratum.</p>
+
+  <div><span class="pagenum" id="page32">{32}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA ANTEDILUVIANA (EHR.)
+  V. H.</span></p>
+
+  <p>Frustules quadrangular, sometimes united in zig-zag chains. Valve quadrangular with more or
+  less concave sides, sometimes cruciform. Surface with angular cells arranged in concentric and
+  radiating lines increasing toward the circumference. At each angle is a large, rounded process,
+  which, as well as the secondary layer, scarcely visible, is finely punctate.</p>
+
+  <p><i>Amphitetras antediluviana</i> Ehr.</p>
+
+  <p><i>Amphitetras tessellata</i> Shad.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Pl. <a href="#plate6"><b>6</b></a>, Fig. 3.</p>
+
+  <p class="sp3">A cruciform variety occurs at Pensauken, N. J., artesian well (Coll. F. J.
+  Keeley).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA GRANULATA
+  ROPER</span></p>
+
+  <p>Valve elliptical-lanceolate, convex, with diagonal rows of puncta 12 in 10 µ and sometimes with
+  small scattered spurs. Processes inflated at the base, obtuse at the ends, which are curved
+  outward toward alternate sides. Near each process and on opposite sides of the longitudinal axis
+  is placed a stout spine bent or curved inward near the middle. Connective zone with diagonal rows
+  of puncta smaller than those on the valve.</p>
+
+  <p>Pavonia, N. J., artesian well. Fossil in the Pleistocene. Along the coast. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate7"><b>7</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA RHOMBUS (EHR.) WM.
+  SM.</span></p>
+
+  <p>Valve rhomboidal, sometimes triangular, with subconical processes. Surface convex with
+  hexagonal reticulations, 7-9 in 10 µ, irregular at the centre and radiating to the circumference.
+  Minute spurs are scattered over the surface, and on each side are usually two or three short
+  spines.</p>
+
+  <p>Common along the coast and fossil in the Miocene and later deposits.</p>
+
+  <p class="sp3">Pl. <a href="#plate7"><b>7</b></a>, Fig. 5 (somewhat inclined, as usually
+  seen).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA SMITHII (RALFS) V.
+  H.</span></p>
+
+  <p>Valve orbicular, convex, with reticulations 5 in 10 µ radiating from the centre and decreasing
+  toward the margin and processes which are truncate. A short spine is found on each side half way
+  between the processes. Zone narrow with fine puncta 12 in 10 µ in longitudinal rows.</p>
+
+  <p><i>Cerataulus smithii</i> Ralfs.</p>
+
+  <p><i>Eupodiscus radiatus</i> Wm. Sm.</p>
+
+  <p>Blue clay. Along the coast southward.</p>
+
+  <p class="sp3">Pl. <a href="#plate7"><b>7</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA TURGIDA (EHR.) WM.
+  SM.</span></p>
+
+  <p>Valve elliptical or orbicular, surface convex. Processes very large, cylindrical, placed
+  obliquely and inclined by the torsion of the frustule. Between the processes are two stout spines,
+  one on each side, frequently forked at the ends. Puncta fine, irregular at the centre and
+  radiating toward the circumference.</p>
+
+  <p><i>Cerataulus turgidus</i> Ehr.</p>
+
+  <p>Blue clay. Along the coast. Quite variable in size.</p>
+
+  <p class="sp3">Pl. <a href="#plate7"><b>7</b></a>, Fig. 7.</p>
+
+  <div><span class="pagenum" id="page33">{33}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA LÆVIS EHR.</span></p>
+
+  <p>Valve suborbicular or triangular, with short, truncate processes. Surface with fine puncta
+  about 13 in 10 µ radiating in straight or curved lines toward the circumference and with fine
+  spurs at intervals. Nearer one process than the other, and about half way between centre and
+  circumference, are two small spines, one on each side. Quite variable in size.</p>
+
+  <p>Blue clay. Common along the coast.</p>
+
+  <p>Pl. <a href="#plate7"><b>7</b></a>, Fig. 9.</p>
+
+  <p class="sp3">Fig. 10 (magnification about 260 diameters only) illustrates sporangial frustules
+  discovered by Mr. T. Chalkley Palmer at Reedy Island, Delaware River. In frustules having a
+  cylindrical form, the endochrome lines the cell-walls in the form of granules which become
+  congregated toward the centre in the sporangia.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA ALTERNANS (BAIL.) V.
+  H.</span></p>
+
+  <p>Valve triangular or, rarely, quadrangular, with sides straight or slightly concave, usually
+  unequal. Angles obtuse, separated from the centre by costate lines. Surface with puncta of
+  irregular shape, large at the centre, with smaller puncta interspersed. In many valves several
+  lines appearing like costæ extend inward from the border in various directions. Angles with small
+  puncta in transverse and longitudinal rows.</p>
+
+  <p><i>Triceratium alternans</i> Bail.</p>
+
+  <p>Blue clay. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate6"><b>6</b></a>, Fig. 7 and probably Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BIDDULPHIA RETICULUM
+  (EHR.)</span></p>
+
+  <p>Frustule quadrangular. Valve triangular with straight or concave sides and rounded angles.
+  Surface convex at the centre and angles. Markings of unequal size, mostly larger at the centre,
+  scattered; at the angles, small puncta in longitudinal rows.</p>
+
+  <p><i>Triceratium sculptum</i> Shad.</p>
+
+  <p><i>Triceratium punctatum</i> Br.</p>
+
+  <p><i>Triceratium obtusum</i> Br.</p>
+
+  <p>For explanation of the synonymy see "Biddulphoid Forms of N. A. Diat.," Proc. Acad. Nat. Sci.,
+  1900, p. 724.</p>
+
+  <p>Blue clay. Along the coast.</p>
+
+  <p class="sp4">Pl. <a href="#plate6"><b>6</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">(<i>c</i>) ANAULEÆ</span></p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Eunotogramma Weisse</span>
+  (1854)</h4>
+
+  <p class="ac">(eu, well, noton, a back, and gramma)</p>
+
+  <p class="sp3">Frustule quadrangular. Valve elliptical or lunate divided by septa which constrict
+  the margin. Surface flat with punctate markings.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTOGRAMMA LÆVE
+  GRUN.</span></p>
+
+  <p>Valve lunate with obtuse ends. Septa, from four to eleven or more. Surface with puncta in
+  transverse and longitudinal rows, sometimes indistinct and scattered.</p>
+
+  <p>Shark River. Rare. More common southward. Fossil at Buckshutem, N. J.</p>
+
+  <p>Pl. <a href="#plate7"><b>7</b></a>, Fig. 11, and Pl. <a href="#plate10"><b>10</b></a>, Fig.
+  15.</p>
+
+  <p class="sp3">I am unable to distinguish between E. læve and E. debile, as intermediate forms
+  occur.</p>
+
+  <div><span class="pagenum" id="page34">{34}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Terpsinoë Ehr.</span></h4>
+
+  <p class="ac">(terpsinoos, gladdening?)</p>
+
+  <p class="sp3">Frustules quadrangular, adnate in filaments, usually free. Valve elliptical or
+  triangular, with undulating sides divided by septa into three or more sections.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TERPSINOË AMERICANA (BAIL.)
+  RALFS</span></p>
+
+  <p>Valve lobed at each end or angle. Central space rounded, hyaline. Surface with fine puncta in
+  radiating lines.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate6"><b>6</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TERPSINOË NOVÆ-CÆSAREÆ
+  BOYER</span></p>
+
+  <p>Valve triangular, with concave sides and broad angles equally three-lobed, separated from the
+  central part by septa. Central space small or absent. Puncta delicate, radiating or scattered. L.
+  of side 62 µ.</p>
+
+  <p>Pleistocene clay at Buckshutem, N. J. Fossil at Wildwood, N. J.</p>
+
+  <p>T. americana, forma trigona Pant.? (Le Diatomiste, Vol. 2, p. 207.)</p>
+
+  <p class="sp4">Pl. <a href="#plate6"><b>6</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">(<i>d</i>) EUODIEÆ</span></p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Euodia Bail.</span> (1860)</h4>
+
+  <p class="ac">(derivation uncertain; apparently from euodia, fragrant, probably a euphemism)</p>
+
+  <p class="sp3">Frustule in zone view cuneate. Valve semi-lunate, coscinodiscoid.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUODIA GIBBA BAIL.</span></p>
+
+  <p>Valve with rounded markings, larger and scattered at the centre, radiating at the circumference
+  and in indefinite straight rows at the semi-radius.</p>
+
+  <p>Delaware Bay (Mann).</p>
+
+  <p>Pl. <a href="#plate5"><b>5</b></a>, Fig. 1.</p>
+
+  <p class="sp4">I have not seen this in the Philadelphia material. The figure is drawn from a
+  specimen from the Gulf Stream, S. Atlantic.</p>
+
+  <div><span class="pagenum" id="page35">{35}</span></div>
+
+  <h1 class="ac" style="margin-bottom:1.6ex;"><span class="larger">PENNATÆ</span></h1>
+
+  <p>Valve zygomorphous. Structure pinnate, not concentric. Valve divided either by a true raphe or
+  cleft or by a linear space or line imitating a raphe.</p>
+
+  <p>Divided into three Groups:</p>
+
+  <p>1. <i>Fragilarioideæ.</i>&mdash;Valves without a raphe; usually with a pseudoraphe or median
+  line.</p>
+
+  <p>2. <i>Naviculoideæ.</i>&mdash;Either one or both valves with a true raphe.</p>
+
+  <p class="sp4">3. <i>Surirelloideæ.</i>&mdash;Valves in which the raphe is concealed near the
+  margin on one or both sides of each valve in a more or less elevated keel or wing.</p>
+
+  <h2>FRAGILARIOIDEÆ</h2>
+
+  <p>(<i>a</i>) <i>Tabellarieæ.</i>&mdash;Valve symmetrical with respect to both the longitudinal
+  and transverse axes; septate, not cuneate.</p>
+
+  <p>(<i>b</i>) <i>Meridioneæ.</i>&mdash;Valve symmetrical with respect to the longitudinal axis,
+  asymmetrical to the transverse axis, cuneate, finely striated.</p>
+
+  <p class="sp4">(<i>c</i>) <i>Fragilarieæ.</i>&mdash;Valve of varied shape, not cuneate; costate or
+  with transverse rows of puncta.</p>
+
+  <h3>(<i>a</i>) TABELLARIEÆ</h3>
+
+  <p>Frustule in zone view rectangular, in valve view linear or linear-elliptical, sometimes
+  constricted in the middle, symmetrical to both axes, not cuneate; with two or more septa or
+  annuli.</p>
+
+  <p>Chromatophores numerous, granular.</p>
+
+  <p><i>Rhabdonema.</i>&mdash;Frustules with numerous septate partitions having one or several
+  foramina. Transverse costæ or rows of coarse puncta.</p>
+
+  <p><i>Tabellaria.</i>&mdash;Frustules with two to six nearly straight septa. Transverse striæ
+  subtly punctate.</p>
+
+  <p><i>Grammatophora.</i>&mdash;Frustules with two sinuate perforate curved septa. Transverse striæ
+  subtly punctate.</p>
+
+  <p><i>Striatella.</i>&mdash;Frustules with alternate partitions, septate or partly so.</p>
+
+  <p class="sp3"><i>Attheya.</i>&mdash;Frustules not septate but with numerous annuli.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Rhabdonema Kuetz.</span> (1844)</h4>
+
+  <p class="ac">(rhabdos, a rod, and nema, a thread)</p>
+
+  <p>Frustules quadrangular, concatenate, composed of numerous septate partitions with transverse
+  costæ or rows of puncta. Valves elliptical, with a pseudoraphe and transverse apparent costæ and
+  punctate lines; the partitions with one or several foramina.</p>
+
+  <p class="sp3">Chromatophores in rosettes of various kinds (Karsten); usually parallel to the
+  septa.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHABDONEMA ARCUATUM (LYNG.)
+  KUETZ.</span></p>
+
+  <p>Valve hyaline at the ends, with transverse rows of puncta producing the appearance of costæ
+  between the rows; pseudoraphe distinct; foramen single.</p>
+
+  <p><i>Diatoma arcuatum</i> Lyngbye.</p>
+
+  <p>Common along the coast.</p>
+
+  <p>Pl. <a href="#plate8"><b>8</b></a>, Figs. 1, 2, and 3; Pl. <a href="#plate40"><b>40</b></a>,
+  Fig. 10.</p>
+
+  <div><span class="pagenum" id="page36">{36}</span></div>
+
+  <p class="sp3">According to T. H. Buffham (Jour. Quek. M. C., Series 2, Vol. 2, p. 131), the
+  frustules are of two kinds, those in which the length and breadth are the same and those which are
+  much lengthened, with a wide hyaline girdle frequently in the middle. At the time of
+  fructification the smaller frustules are attached to a larger one which produces a sporangium at
+  the end of the girdle from which the other end of the frustule has disappeared, or, if the two
+  halves of the frustule remain, two sporangia are formed.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHABDONEMA MINUTUM
+  KUETZ.</span></p>
+
+  <p>Frustules small; valve not smooth at the ends, elliptical or lanceolate-elliptical, with
+  transverse rows of puncta; pseudoraphe distinct. Foramen single, alternating above and below in
+  adjoining partitions.</p>
+
+  <p>Common in the blue clay and along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Fig. 7 and Pl. <a
+  href="#plate38"><b>38</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHABDONEMA ADRIATICUM
+  KUETZ.</span></p>
+
+  <p>Valve linear-lanceolate, with smooth angles; rows of puncta transverse, the intervals appearing
+  as costæ, as in arcuatum. Foramina, three.</p>
+
+  <p>Blue clay in the Pensauken and Pavonia deposits and along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 4, 5 and 6.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Tabellaria Ehr.</span> (1839)</h4>
+
+  <p class="ac">(tabella, a tablet)</p>
+
+  <p>Frustules quadrangular, adnate in filaments, frequently found in zig-zag chains, united by a
+  gelatinous isthmus, at length separating. Valve linear, inflated in the middle and at the ends;
+  striæ transverse.</p>
+
+  <p class="sp3">Chromatophores numerous, small, along the zones.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TABELLARIA FENESTRATA (LYNG.)
+  KUETZ.</span></p>
+
+  <p>Valve elongated; pseudoraphe narrow; transverse striæ faint. In the zone view a straight septum
+  is shown at each end of a valve.</p>
+
+  <p>Common, especially in the cedar swamps and ponds of the Pine Barren region, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 11 and 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TABELLARIA FLOCCULOSA (ROTH)
+  KUETZ.</span></p>
+
+  <p>Valve linear, with median inflation larger than the terminal; pseudoraphe rather broad in the
+  middle; transverse striæ subtly punctate. In zone view the frustules are quadrangular, or nearly
+  so, with about six sometimes curved septa at one end alternating with those on the other end.</p>
+
+  <p><i>Conferva flocculosa</i> Roth.</p>
+
+  <p>Common especially in the Pine Barrens of New Jersey.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 8, 9 and 10.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Grammatophora Ehr.</span> (1840)</h4>
+
+  <p class="ac">(from gramma, a letter, and phoreo, I bear)</p>
+
+  <p>Frustules quadrangular, adnate, in zig-zag, united by an isthmus, or, usually, found free;
+  divided by two sinuate and perforate curved septa. Valve linear or oblong, sometimes with sinuate
+  sides, and with a pseudoraphe and transverse punctate lines.</p>
+
+  <p class="sp3">Chromatophores granular.</p>
+
+  <div><span class="pagenum" id="page37">{37}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GRAMMATOPHORA MARINA (LYNG.)
+  KUETZ.</span></p>
+
+  <p>Valve linear-elliptical, with smooth apices. Septum with a wide undulation near its origin,
+  thence straight and incrassate at the end. Striæ in quincunx, 18-21 in 10 µ.</p>
+
+  <p><i>Diatoma marinum</i> Lyngbye.</p>
+
+  <p>Blue clay. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 17 and 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GRAMMATOPHORA MARINA VAR.
+  SUBTILISSIMA (BAIL.) V. H.</span></p>
+
+  <p>Valve linear, slightly constricted near the smooth apices. Septum undulated near its origin and
+  then straight, incrassate at the end. Puncta in quincunx very subtle, 34-36 in 10 µ.</p>
+
+  <p><i>Grammatophora subtilissima</i> Bail.</p>
+
+  <p>Grammatophora oceanica var. subtilissima (Bail.) V. H., according to De Toni. G. marina and G.
+  oceanica are united by some authors; the latter has more subtle striæ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 13 and 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GRAMMATOPHORA SERPENTINA
+  RALFS</span></p>
+
+  <p>Valve linear-elliptical, long, measuring to 150 µ (De Toni); smooth at the apices. Septum with
+  numerous undulations and hooked at the apex. Puncta in quincunx, 17 in 10 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Fig. 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GRAMMATOPHORA ANGULOSA VAR.
+  HAMULIFERA (KUETZ.) GRUN.</span></p>
+
+  <p>Frustule nearly quadrate; valve with rounded but not smooth apices. Septum bent into a sharp
+  angle near its origin and ending in a broad hook. Puncta in transverse rows, 14 in 10 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 15 and 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GRAMMATOPHORA ISLANDICA
+  EHR.</span></p>
+
+  <p>Frustule oblong; valve elliptical-lanceolate. Septum robust with several undulations and hooked
+  at the end. Pseudoraphe distinct; transverse rows of puncta, 10 in 10 µ.</p>
+
+  <p>Reported by Kuetzing in the Atlantic Ocean and by Kain at Belmar, N. J. I have not found it on
+  our coast and I believe, in some cases, it has been confused with <i>G. angulosa</i> var.
+  <i>hamulifera</i>. The figure is drawn from an Iceland form in H. L. Smith T. S., 186.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 19 and 20.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Striatella Ag.</span> (1832)</h4>
+
+  <p class="ac">(dim. of stria, referring to the lines on the frustule)</p>
+
+  <p class="sp3">Frustules tabulate, adnate in short, stipitate filaments, scarcely siliceous,
+  divided into partitions, septate or partly so at alternate ends.</p>
+
+  <div><span class="pagenum" id="page38">{38}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STRIATELLA UNIPUNCTATA (LYNG.)
+  AG.</span></p>
+
+  <p>Frustules with numerous bent septa extending the entire length. Valve lanceolate, somewhat
+  unsymmetrical, subtly punctate, with pseudoraphe quite distinct.</p>
+
+  <p>"The specific name is derived from the appearance of the endochrome which in the living
+  specimen is invariably collected in a central mass with slender threads radiating in all
+  directions toward the cell-wall" (Wm. Sm.). Pyrenoids cuneate, in the centre of the endochrome,
+  numerous.</p>
+
+  <p>Long Island Sound and along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Figs. 22 and 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STRIATELLA INTERRUPTA (EHR.)
+  HEIB.</span></p>
+
+  <p>Frustules quadrangular, with robust alternate septa extending to the middle. Puncta in
+  quincunx, 22 in 10 µ.</p>
+
+  <p><i>Tessella interrupta</i> Ehr.</p>
+
+  <p>Very rare along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate8"><b>8</b></a>, Fig. 24. (From a form found at Stonington,
+  Conn.)</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Attheya West</span> (1860)</h4>
+
+  <p class="ac">(named after Thomas Atthey)</p>
+
+  <p class="sp3">Frustules quadrangular, tabulate, with numerous annuli. Valve
+  elliptical-lanceolate, with a pseudoraphe and a central punctum. Extending from each end is a
+  strong spine half as long as the valve.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ATTHEYA DECORA WEST</span></p>
+
+  <p>The only species. Diagnosis of the genus. The valves are imperfectly siliceous, scarcely
+  visible in balsam.</p>
+
+  <p>Very local. Abundant at Shark River, N. J.</p>
+
+  <p class="sp4">Pl. <a href="#plate8"><b>8</b></a>, Fig. 25.</p>
+
+  <h3>(<i>b</i>) MERIDIONEÆ</h3>
+
+  <p>Valve symmetrical in zone and valve view along the sagittal line, but asymmetrical to the
+  transverse axis, cuneate. In zone view sometimes with wedge-shaped septa. Valve finely striated,
+  without central and usually without terminal nodules; a pseudoraphe present.</p>
+
+  <p><i>Licmophora.</i>&mdash;Frustules cuneate in stipitate fan-shaped fascicles.</p>
+
+  <p class="sp3"><i>Meridion.</i>&mdash;Frustules cuneate in spiral fascicles.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Licmophora Ag.</span> (1827)</h4>
+
+  <p class="ac">(licmos, a fan, and phoreo, I bear)</p>
+
+  <p class="sp3">Frustules wedge-shaped, joined together into fan-shaped, stipitate fascicles. Valve
+  cuneate, rounded at both ends, septate. Chromatophores granular, round or oval in our species.</p>
+
+  <div><span class="pagenum" id="page39">{39}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANALYSIS OF SPECIES</span></p>
+
+  <p>(In accordance, so far as it relates to our species, with the classification of C.
+  Mereschkowsky, Diagnoses of New Licmophoræ, Nuova Notarisia, 1901.)</p>
+
+  <table class="sp3 mc w50" title="Species of Licmophora" summary="Species of Licmophora">
+    <tr class="pb05">
+      <td class="itp05">Placatæ&mdash;valve narrow, striæ very fine, septa superficial</td>
+      <td class="vbm">flabellata</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Dubiæ&mdash;valve bacilliform, septa shallow, frustule with thick walls</td>
+      <td class="vbm">ovulum</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Paradoxæ&mdash;valve with lower end produced, striæ fine, pseudoraphe
+      distinct, septa deep</td>
+      <td class="vbm">paradoxa<br/>
+      gracilis<br/>
+      tincta<br/>
+      baileyi ?</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Lyngbyeæ&mdash;valve narrow, attenuated at both ends, distinct, septa
+      deep</td>
+      <td class="vbm">lyngbyei</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Peristriatæ&mdash;valve broad, pseudoraphe wide, striæ robust</td>
+      <td class="vbm">ehrenbergii</td>
+    </tr>
+  </table>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA FLABELLATA (CARM.)
+  AG.</span></p>
+
+  <p>Frustule elongate, narrow; valve narrow, lanceolate-cuneate, enlarged at the base; striæ very
+  fine, 30 in 10 µ.</p>
+
+  <p><i>Echinella flabellata</i> Carm.</p>
+
+  <p><i>Licmophora splendida</i> Wm. Sm.</p>
+
+  <p>Common along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Figs. 1 and 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA OVULUM MER.</span></p>
+
+  <p>Valve ovate, attenuated to the rounded inferior apex; pseudoraphe indistinct, striæ fine, 24 in
+  10 µ. Zone view broad, cuneate, angles rounded, inferior apex broad; frustule robust, septa
+  superficial, straight. (Mereschkowsky, in part.)</p>
+
+  <p>Atlantic City. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Figs. 8 and 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA PARADOXA (LYNG.)
+  AG.</span></p>
+
+  <p>Frustule broad, with rounded angles; septa curved; valve ovate, inferior apex produced.
+  Pseudoraphe distinct; striæ varying from 25 below to 30 above in 10 µ.</p>
+
+  <p><i>Echinella paradoxa</i> Lyng.</p>
+
+  <p><i>Rhipidophora paradoxa</i> Kuetz.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Figs. 6 and 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA GRACILIS (EHR.)
+  GRUN.</span></p>
+
+  <p>Frustule cuneate, narrow, with sinuate margin; valve clavate, linear at the base; striæ, 20 to
+  22 in 10 µ.</p>
+
+  <p>New Rochelle. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA GRACILIS VAR. ELONGATA
+  (KUETZ.) DE TONI</span></p>
+
+  <p>As in the type, but more graceful and with deeper septa.</p>
+
+  <p><i>Rhipidophora elongata</i> Kuetz.</p>
+
+  <p>Along the coast. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Figs. 12 and 13.</p>
+
+  <div><span class="pagenum" id="page40">{40}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA TINCTA (AG.)
+  GRUN.</span></p>
+
+  <p>Frustules cuneate, narrow, usually found in twos. Valve clavate, hyaline, rather broad at the
+  base; septa moderately deep; pseudoraphe indistinct; striæ, 27 at the base, 30 in the middle and
+  33 at the apex in 10 µ.</p>
+
+  <p><i>Gomphonema tinctum</i> Ag.</p>
+
+  <p>Along the coast. Abundant from about the middle of July to the middle of August.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Figs. 14 and 15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA BAILEYI (EDW.)
+  GRUN.</span></p>
+
+  <p>Frustule broadly cuneate or with convex margins, rarely almost orbicular; valve spatulate or
+  ovate with slender, produced base; septa very deep; pseudoraphe distinct; striæ 20 in 10 µ.</p>
+
+  <p><i>Podosphenia baileyi</i> (Edw.) Lewis.</p>
+
+  <p>Long Island Sound and upper coast of New Jersey.</p>
+
+  <p>This form is placed in a doubtful position by Mereschkowsky. As it corresponds more closely to
+  the Paradoxæ, it is placed here provisionally. The girdle face and apex of the valve are round,
+  the pseudoraphe is distinct and the septa deep, but the stipe is short.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Fig. 10 and Pl. <a
+  href="#plate38"><b>38</b></a>, Figs. 3 and 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA LYNGBYEI (KUETZ.)
+  GRUN.</span></p>
+
+  <p>Frustule cuneate, slightly rounded at the angles. Valve oblanceolate; pseudoraphe distinct;
+  septa deep; striæ, 12 in 10 µ below, and 16 in 10 µ above.</p>
+
+  <p><i>Podosphenia lyngbyei</i> Kuetz.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Figs. 3 and 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">LICMOPHORA EHRENBERGII (KUETZ.)
+  GRUN.</span></p>
+
+  <p>Frustule cuneate, broad. Valve obovate-lanceolate; pseudoraphe wide; striæ coarse, 8 in 10 µ,
+  moniliform.</p>
+
+  <p><i>Podosphenia ehrenbergii</i> Kuetz.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate9"><b>9</b></a>, Fig. 5.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Meridion Ag.</span> (1824)</h4>
+
+  <p class="ac">(merizo, I divide)</p>
+
+  <p>Frustules in zone view cuneate, adnate in circular or spiral fasciæ, at length becoming free.
+  Valve symmetrical with respect to the longitudinal axis, more or less cuneate; costæ and striæ
+  transverse.</p>
+
+  <p class="sp3">Chromatophores numerous, small, elongated, in irregular rows on the zone
+  (Pfitzer).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MERIDION CIRCULARE (GREV.)
+  AG.</span></p>
+
+  <p>Transverse costæ coarse, variable in number and distance apart, sometimes interrupted or
+  indistinct; striæ interstitial, 16 in 10 µ.</p>
+
+  <p>In springs and small streams of pure water.</p>
+
+  <p><i>Echinella circularis</i> Grev.</p>
+
+  <div><span class="pagenum" id="page41">{41}</span></div>
+
+  <p>Meridion constrictum Ralfs, sometimes given as a variety of M. circulare, differs only in the
+  constriction below the apex. The two kinds of frustules are usually found growing together and as
+  the variation is often extremely slight they are here included under the earlier name.</p>
+
+  <p>Pl. <a href="#plate10"><b>10</b></a>, Figs. 1, 2 and 3.</p>
+
+  <p>Fig. 1 represents the constricted form which is the more common. Fig. 3 is a sporangial
+  form.</p>
+
+  <p>The sporangial frustules vary in shape and size, some being long and slender, others clavate,
+  but they are all more or less tumid in the middle, with costæ more indefinite than in perfect
+  valves. All gradations occur, one end becoming shorter until the valve has the shape of the
+  variety known as constrictum. It would seem, therefore, that the non-constricted form is a passage
+  from the sporangial to the smaller or adult form, or is of no specific importance. All forms are
+  found living together. The adult frustules are the smaller ones; it is from them that the
+  sporangia are produced.</p>
+
+  <p>Meridion intermedium H. L. Smith (Amer. Quart. Mic. Jour., Vol. 1, p. 12) is characterized by
+  less evident costæ and is more delicate in general appearance. Some forms are capitate and others
+  are not. Prof. Smith compares the M. intermedium with Peronia erinacea Bréb. and Arnott which he
+  has named M. erinaceum, hitherto found only in Europe, and points out the relation of the two
+  forms to Licmophora. An examination of the H. L. S. type slides of the two diatoms proves that
+  Peronia has very delicate costæ and a distinct pseudoraphe not noticeable in Meridion. On the
+  slide of Peronia are frustules exactly similar to certain of the sporangial variations of M.
+  circulare.</p>
+
+  <p class="sp4">The fan-like arrangement of Licmophora, the marine form, and the circular chains of
+  Meridion, the fresh-water genus, are similar. Both are stipitate at the beginning of their
+  growth.</p>
+
+  <h3>(<i>c</i>) FRAGILARIEÆ</h3>
+
+  <p>Divided into three sections:</p>
+
+  <p><i>Diatominæ.</i>&mdash;Valve circular, elliptical to linear, quadrate or cruciform, with
+  transverse costæ; without raphe, a pseudoraphe sometimes wanting.</p>
+
+  <p><i>Fragilariinæ.</i>&mdash;Valve elongate, with small central and terminal elevations, without
+  costæ but with transverse punctate striæ; without genuine central nodule.</p>
+
+  <p class="sp4"><i>Eunotiinæ.</i>&mdash;Valve lunate; a raphe sometimes partially formed with
+  terminal nodules near the edges.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIATOMINÆ</span></p>
+
+  <p><i>Diatoma.</i>&mdash;Frustules in filaments. Valve linear or elliptical, costate.</p>
+
+  <p><i>Plagiogramma.</i>&mdash;Frustules in fasciæ or free. Valve costate.</p>
+
+  <p class="sp3"><i>Opephora.</i>&mdash;Valve costate, with an inner punctate stratum.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Diatoma De Candolle</span> (1805) em.
+  <span class="sc">Heib.</span> (1863)</h4>
+
+  <p class="ac">(diatemno, I cut in two)</p>
+
+  <p>Frustules oblong or quadrate, adnate in filaments, attached by alternate angles and finally
+  separating. Valve linear or elliptical, with transverse costæ and rows of puncta and a
+  pseudoraphe.</p>
+
+  <p class="sp3">Chromatophores large granules without definite arrangement. (See Pl. <a
+  href="#plate40"><b>40</b></a>, Fig. 11.)</p>
+
+  <div><span class="pagenum" id="page42">{42}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIATOMA VULGARE BORY.</span></p>
+
+  <p>Valve elliptical-lanceolate, with apices sometimes rostrate or capitate; pseudoraphe narrow;
+  costæ, 5 in 10 µ.</p>
+
+  <p>Common everywhere in pure fresh water and extremely variable.</p>
+
+  <p>Pl. <a href="#plate10"><b>10</b></a>, Figs. 9 and 10.</p>
+
+  <p>Var. elongatum (Ag.) = var. ehrenbergii (Kuetz.)&mdash;elliptical-lanceolate, constricted near
+  the apex.</p>
+
+  <p>Var. grande (Wm. Sm.) Grun.&mdash;linear, elongated, constricted near the apices.</p>
+
+  <p>Pl. <a href="#plate10"><b>10</b></a>, Fig. 4.</p>
+
+  <p class="sp3">Both of these varieties, with numerous intermediate forms, are abundant near
+  Newtown Square. Varieties of Grunow, known as breve, ovate-lanceolate; productum, ovate-lanceolate
+  with produced apices; capitulatum, lanceolate with capitate extremities, are mingled together in
+  the same gathering.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIATOMA ANCEPS (EHR.)
+  KIRCHN.</span></p>
+
+  <p>Valve linear with rostrate apices; costæ robust; striæ delicate, 20 in 10 µ. Zone view
+  quadrangular.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Figs. 5 and 6. Fig. 11, Pl. <a
+  href="#plate40"><b>40</b></a>, shows frustules containing the nuclei and chromatophores.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIATOMA HIEMALE (LYNG.)
+  HEIB.</span></p>
+
+  <p>Valve ovate-lanceolate to lanceolate; apices obtuse, not produced. Costæ not numerous, robust;
+  striæ moniliform. Zone view quadrate, the costæ as septa deeply dividing the valve into convex
+  elevations.</p>
+
+  <p>Common in springs.</p>
+
+  <p>Pl. <a href="#plate10"><b>10</b></a>, Figs. 7 and 8.</p>
+
+  <p class="sp3">In all species of Diatoma a punctum, or pore, is observed, usually at alternate
+  ends of the two valves, by means of which a communication exists between adjoining frustules and
+  causes them to adhere in zig-zag chains when partially separated.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Plagiogramma Grev.</span> (1859)</h4>
+
+  <p class="ac">(plagios, on the side, and gramma, a letter)</p>
+
+  <p>Frustules quadrangular, adnate in fasciæ, or free. Valve linear, elliptical, or
+  elliptical-lanceolate, divided by two or more median and two terminal costæ or with a central and
+  two terminal hyaline spaces.</p>
+
+  <table class="sp3 mc w50" title="Species of Plagiogramma" summary="Species of Plagiogramma">
+    <tr class="pb05">
+      <td colspan="2">Valve with two median and two terminal costæ:</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Linear, pseudoraphe distinct</td>
+      <td class="vbm">pygmæum</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Linear, with striæ at the ends</td>
+      <td class="vbm">wallichianum</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Ovate-lanceolate</td>
+      <td class="vbm">obesum</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">Valve without costæ but with central and terminal nodules: pseudoraphe
+      absent</td>
+      <td class="vbm">tessellatum</td>
+    </tr>
+  </table>
+
+  <div><span class="pagenum" id="page43">{43}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLAGIOGRAMMA PYGMÆUM
+  GREV.</span></p>
+
+  <p>Valve linear-elliptical; pseudoraphe distinct; rows of granules transverse, usually six in each
+  compartment, moniliform, three on each side.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLAGIOGRAMMA WALLICHIANUM
+  GREV.</span></p>
+
+  <p>Valve linear, rounded at the ends; pseudoraphe absent; transverse rows of granules, six or
+  seven in each compartment, and two or three rows of smaller granules at each end.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLAGIOGRAMMA OBESUM
+  GREV.</span></p>
+
+  <p>Valve rhombic-lanceolate, the costæ scarcely visible; pseudoraphe rather wide; rows of
+  granules, about seven in each compartment, slightly radiating.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLAGIOGRAMMA TESSELLATUM
+  GREV.</span></p>
+
+  <p>Valve elliptical-lanceolate; central space transversely elliptical to the major axis, half the
+  diameter of the valve; terminal spaces more or less circular or ovate. Granular markings large,
+  quadrangular, in transverse rows. Pseudoraphe not distinct. As the central space does not reach
+  the margin, it is a question whether this form is a Plagiogramma or a new genus.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 11.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Opephora Petit</span> (1888)</h4>
+
+  <p class="ac">(ope, an opening, and phoreo)</p>
+
+  <p>Frustule rectangular. Valve cuneiform, linear or elliptical-lanceolate, with broad, transverse
+  striæ and a well-defined pseudoraphe or median area.</p>
+
+  <p class="sp3">The genus "portant des stries en forme de boutonnières," as Petit remarks, is quite
+  near Fragilaria, under which the species here described were originally included. (See Schmidt's
+  Atlas, Pl. 298, where numerous forms of F. pinnata are figured.)</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">OPEPHORA SCHWARTZII (GRUN.)
+  PETIT</span></p>
+
+  <p>Valve obovate-lanceolate or nearly linear with rounded apices; striæ transverse, broad, 3 or 4
+  in 10 µ; median area lanceolate.</p>
+
+  <p>An inner stratum, with puncta in transverse rows, is apparent.</p>
+
+  <p>Blue clay. Not uncommon. Variable in size.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Figs. 16 and 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">OPEPHORA PACIFICA (GRUN.)
+  PETIT</span></p>
+
+  <p>Valve linear, oblong, with rounded apices. Median area linear, narrow; striæ punctate.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate10"><b>10</b></a>, Fig. 18.</p>
+
+  <p class="sp3">Petit (Diat. Cap Horn) in his diagnosis states that the valves are cuneiform, but
+  they are not always so.</p>
+
+  <div><span class="pagenum" id="page44">{44}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">OPEPHORA PINNATA VAR. LANCEOLATA
+  N. VAR.</span></p>
+
+  <p>Valve lanceolate; costæ slightly radiate, punctate; median area broad, lanceolate.</p>
+
+  <p>Differs from O. pinnata in outline, radiation of the costæ and median area.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p class="sp4">Pl. <a href="#plate10"><b>10</b></a>, Fig. 17.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIINÆ</span></p>
+
+  <p><i>Fragilaria.</i>&mdash;Frustules in fasciæ. Valve with transverse striæ. Pseudoraphe
+  indistinct.</p>
+
+  <p><i>Rhaphoneis.</i>&mdash;Striæ radiate; pseudoraphe distinct.</p>
+
+  <p><i>Dimerogramma.</i>&mdash;Pseudoraphe broad.</p>
+
+  <p><i>Trachysphenia.</i>&mdash;Valve cuneiform.</p>
+
+  <p><i>Synedra.</i>&mdash;Valve elongate.</p>
+
+  <p class="sp3"><i>Asterionella.</i>&mdash;Frustules in star-shaped clusters.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Fragilaria (Lyng.) Rab.</span></h4>
+
+  <p class="ac">(fragilis, because of the fasciæ easily breaking up)</p>
+
+  <p>Frustules rectangular, adnate in fasciæ, soon breaking up. Valve lanceolate, oblong or
+  elliptical in general outline, with convex or sinuate margins; without costæ; pseudoraphe narrow
+  or indistinct; striæ transverse. Chromatophores vary according to species. In some they consist of
+  four bands on the valves; in others they are granular (Mereschkowsky).</p>
+
+  <p class="sp3">Brun divides the genus into two sections, Fragilaria proper and Staurosira. The
+  former, with an indistinct pseudoraphe, includes the species virescens, arctica, undata and
+  linearis, while the latter, with distinct pseudoraphe, includes capucina, harrisonii, construens
+  and parasitica.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA VIRESCENS
+  RALFS</span></p>
+
+  <p>Frustules in long fasciæ. Valve elliptical-lanceolate, obtuse at the apices; pseudoraphe
+  indistinct; striæ, 17 in 10 µ, punctate.</p>
+
+  <p>Very common in springs and pure streams. The fasciæ are often a foot or more in length.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Figs. 20 and 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA ARCTICA
+  GRUN.</span></p>
+
+  <p>Valve oblong or elliptical, 10 µ in length; striæ subtle, with coarse, short striæ at intervals
+  on the margin and evident in zone view.</p>
+
+  <p>Marine. Common at Cape May, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Figs. 22 and 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA UNDATA WM.
+  SM.</span></p>
+
+  <p>Valve in general outline linear-elliptical, with extremities produced; striæ subtle;
+  pseudoraphe distinct.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Figs. 24, 25, 27, 28 and 29.</p>
+
+  <div><span class="pagenum" id="page45">{45}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA LINEARIS
+  CSTR.</span></p>
+
+  <p>Valve linear, with rounded apices; striæ subtle; pseudoraphe indistinct.</p>
+
+  <p>Marine. Cape May.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 37. Fig. 36 is an indeterminate form
+  occasionally found in the blue clay.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA CAPUCINA VAR.
+  MESOLEPTA RAB.</span></p>
+
+  <p>Valve linear, constricted at the hyaline middle; apices slightly produced; striæ, 17 in 10 µ.
+  Quite variable in size.</p>
+
+  <p>Schuylkill River. Morrisville (Keeley).</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 34.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA HARRISONII (WM. SM.)
+  GRUN.</span></p>
+
+  <p>Frustules rectangular, solitary or in twos. Valve cruciform; pseudoraphe narrow, lanceolate;
+  striæ robust, radiating in the middle, composed of confluent puncta, larger at the
+  circumference.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 31.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA CONSTRUENS (EHR.)
+  GRUN.</span></p>
+
+  <p>Valve in general outline lanceolate, with produced apices; pseudoraphe lanceolate, distinct or
+  broad; striæ subtle, 15 in 10 µ. L. of valve, 10-45 µ.</p>
+
+  <p><i>Staurosira construens</i> Ehr.</p>
+
+  <p><i>Odontidium tabellaria</i> Wm. Sm.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 30.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRAGILARIA PARASITICA (WM.
+  SM.)</span></p>
+
+  <p>Frustules solitary or in twos. Valve lanceolate, sometimes constricted in the middle;
+  pseudoraphe wide, lanceolate; striæ subtle. Parasitic on other diatoms.</p>
+
+  <p><i>Odontidium parasiticum</i> Wm. Sm.</p>
+
+  <p>Not common. Media (Palmer).</p>
+
+  <p>In the constricted form it is known as F. construens var. binodis (Ehr.) Grun.</p>
+
+  <p>Pl. <a href="#plate10"><b>10</b></a>, Fig. 35.</p>
+
+  <p class="sp3">An examination of the synonymy of the species of Fragilaria will convince the
+  student of the difficulty of determining the correct name even in well-known forms. If all of the
+  species of Fragilaria proper have granular chromatophores, and all of Staurosira are
+  placcochromatic, a satisfactory division can be made, but so long as these facts are not known in
+  all species, and as authors have repeatedly confused the two divisions, the nomenclature will be
+  uncertain. F. harrisonii is probably in any case to be separated from the others. De Toni includes
+  it under its original name of Odontidium, which genus he places near to Diatoma. The number of
+  species in our locality is too limited to render further discussion of any value.</p>
+
+  <div><span class="pagenum" id="page46">{46}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Rhaphoneis Ehr.</span> (1844)</h4>
+
+  <p class="ac">(rhaphis, a needle)</p>
+
+  <p class="sp3">Frustule in zone view linear. Valve lanceolate or elliptical-lanceolate;
+  pseudoraphe distinct; striæ radiating, moniliform.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHAPHONEIS AMPHICEROS
+  EHR.</span></p>
+
+  <p>Valve lanceolate, broad, with apices produced; striæ in curved lines, moniliform, the large
+  granules in longitudinal lines.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 38.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHAPHONEIS AMPHICEROS VAR.
+  RHOMBICA GRUN.</span></p>
+
+  <p>Valve as in type form but shorter, with larger and more remote granules.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Figs. 39 and 40.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHAPHONEIS BELGICA VAR.
+  INTERMEDIA GRUN.</span></p>
+
+  <p>Valve lanceolate, rostrate; granules in longitudinal and nearly transverse, not radiating,
+  lines.</p>
+
+  <p>Absecon, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate10"><b>10</b></a>, Fig. 41.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Dimerogramma Ralfs</span> (1861)</h4>
+
+  <p class="ac">(dis, two, meros, a part, gramma, a letter)</p>
+
+  <p class="sp3">Frustules quadrangular, inflated at the angles, in fasciæ. Valve ovate or
+  lanceolate; striæ moniliform, transverse or slightly radiate; median area or pseudoraphe broad,
+  lanceolate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIMEROGRAMMA MARINUM (GREG.)
+  RALFS</span></p>
+
+  <p>Valve lanceolate or linear and inflated in the middle; striæ moniliform, transverse or slightly
+  radiate; median area linear or lanceolate, sometimes not reaching the smooth extremities; striæ, 8
+  in 10 µ.</p>
+
+  <p>Pl. <a href="#plate12"><b>12</b></a>, Figs. 9 and 10.</p>
+
+  <p class="sp3">Fig. 9 differs in its lanceolate outline, in having four puncta on each side in a
+  row, and in the striæ which are radiate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIMEROGRAMMA SURIRELLA (EHR.)
+  GRUN.</span></p>
+
+  <p>Valve elliptical-lanceolate, with rounded apices; striæ moniliform, radiate; pseudoraphe
+  narrow, lanceolate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Fig. 11.</p>
+
+  <div><span class="pagenum" id="page47">{47}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIMEROGRAMMA MINUS (GREG.)
+  RALFS</span></p>
+
+  <p>Valve rhombic-lanceolate; striæ punctate, radiate; pseudoraphe lanceolate; apices smooth.</p>
+
+  <p>Blue clay. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Figs. 12, 13, 14.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Trachysphenia Petit</span>
+  (1877)</h4>
+
+  <p class="ac">(trachys, rough, and sphen, a wedge)</p>
+
+  <p class="sp3">Frustules rectangular. Valve cuneiform with coarse puncta in transverse and
+  longitudinal lines; pseudoraphe narrow, linear. One species only.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TRACHYSPHENIA AUSTRALIS
+  PETIT</span></p>
+
+  <p>Characters of the genus. Valve small; puncta, 6 in 10 µ. Allied to Dimerogramma.</p>
+
+  <p>Shark River, N. J. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Fig. 15.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Synedra Ehr.</span> (1830)</h4>
+
+  <p class="ac">(synedrion, a sitting together)</p>
+
+  <p>Frustules adnate in small stipitate clusters or free. Valve elongate, linear or
+  linear-lanceolate; pseudoraphe distinct; costæ absent.</p>
+
+  <p>The genus Synedra has few distinctive characters. As Brun remarks (Diat. des Alpes et du Jura,
+  p. 122), the dilatation of the extremities and the pseudo-nodule are of little value in
+  classification, as the intermediate forms are so numerous. Fragilaria occurs in very long ribbons
+  or fasciæ, Synedra in short fasciæ or radiating clusters. Fragilaria is seldom longer than three
+  or four times the width, while Synedra is nearly always so. The former has fine, often subtle,
+  markings and narrow pseudoraphe, while the latter has coarser punctate striæ and a more distinct
+  pseudoraphe.</p>
+
+  <p class="sp3">Chromatophores usually consist of two bands, one on each of the valves. Karsten
+  states that in the marine forms the chromatophores are oval or polygonal discs, each of which
+  usually encloses a pyrenoid.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA ULNA (NITZSCH)
+  EHR.</span></p>
+
+  <p>Frustules solitary or in twos. Valve 150-250 µ in length, linear or linear-lanceolate, with
+  rostrate apices; striæ, 9 in 10 µ.</p>
+
+  <p>Common in rivers and streams.</p>
+
+  <p>Pl. <a href="#plate11"><b>11</b></a>, Figs. 4, 7 and 11 (?).</p>
+
+  <p>Frequently interrupted in the middle. The distinction made by Wm. Smith as to the presence or
+  absence of the central blank space is probably not necessary, as both forms are found which are
+  otherwise identical.</p>
+
+  <p class="sp3">Fig. 5 represents the formation of a sporangial frustule which differs from the
+  usual form in its inflated ends prolonged into rostrate apices. Figs. 1 and 6 are sporangial
+  frustules.</p>
+
+  <div><span class="pagenum" id="page48">{48}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA BICEPS (KUETZ.)
+  SCHMIDT</span></p>
+
+  <p>Valve sublanceolate, inflated at the ends, apices rounded; central space not always distinct;
+  pseudoraphe narrow; striæ radiate at the ends.</p>
+
+  <p>This is not Kuetzing's species, if the descriptions and figures are accepted, nor is it H. L.
+  Smith's Type No. 545, which is S. ulna var. danica, nor is it S. biceps Wm. Smith, but it is
+  exactly Schmidt's form (Atlas, Pl. 303, Figs. 10-15).</p>
+
+  <p>Schuylkill River.</p>
+
+  <p class="sp3">Pl. <a href="#plate11"><b>11</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA DANICA KUETZ.</span></p>
+
+  <p>Valve lanceolate, suddenly constricted at the rounded apices; central space frequently
+  absent.</p>
+
+  <p>Very common in streams.</p>
+
+  <p>Pl. <a href="#plate11"><b>11</b></a>, Fig. 2.</p>
+
+  <p class="sp3">The figure represents an unusually large form. It differs from S. ulna only in its
+  apices.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA CAPITATA EHR.</span></p>
+
+  <p>Valve long, linear, dilated into triangular acute apices; pseudoraphe distinct; striæ radiate
+  at the ends.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate11"><b>11</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA ACUS KUETZ.</span></p>
+
+  <p>Valve very narrow, lanceolate, acicular, with obtuse apices.</p>
+
+  <p>Common in the Schuylkill River.</p>
+
+  <p class="sp3">Pl. <a href="#plate11"><b>11</b></a>, Figs. 9 and 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA GOULARDI BRÉB.</span></p>
+
+  <p>Valve constricted in the middle; apices sub-acute, sometimes slightly rostrate or capitate;
+  central space evident.</p>
+
+  <p>Neshaminy Creek (Palmer). Blue clay. Crum Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate11"><b>11</b></a>, Figs. 12 and 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA PULCHELLA (RALFS)
+  KUETZ.</span></p>
+
+  <p>Valve lanceolate, tapering to the sub-acute, rostrate or slightly capitate apices; dilated at
+  the central hyaline space; pseudoraphe distinct. Very variable in size.</p>
+
+  <p>Crum Creek. Schuylkill River. Rather common.</p>
+
+  <p class="sp3">Pl. <a href="#plate11"><b>11</b></a>, Figs. 14, 15, 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA PULCHELLA VAR. ABNORMIS
+  MACCHIATI?</span></p>
+
+  <p>Valve as in type form, except that one end is curved like a beak, as in S. hamata Wm. Sm.,
+  which it resembles.</p>
+
+  <p>Not uncommon in the Schuylkill River.</p>
+
+  <p class="sp3">Pl. <a href="#plate11"><b>11</b></a>, Fig. 17.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA OXYRHYNCHUS VAR. UNDULATA
+  GRUN.</span></p>
+
+  <p>Valve linear-lanceolate with produced rostrate apices, asymmetrical, sigmoid; pseudoraphe
+  narrow; pseudo-nodule large.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Fig. 1.</p>
+
+  <div><span class="pagenum" id="page49">{49}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA PULCHELLA VAR. FLEXELLA
+  N. VAR.</span></p>
+
+  <p>Frustule slightly attenuated at the ends, truncate, somewhat tumid in the middle and flexed.
+  Valve lanceolate, with obtuse or subcapitate apices and with two almost imperceptible
+  constrictions at the middle producing a tumid appearance; pseudoraphe distinct; pseudo-nodule
+  absent. L. 56 µ; striæ, 14-16 in 10 µ.</p>
+
+  <p>Some valves are bent and incised on one side. The outline of the valve is that of
+  pulchella.</p>
+
+  <p>Common at Newtown Square.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA RADIANS KUETZ.</span></p>
+
+  <p>Frustules linear, in small fasciæ. Valve 34 µ in length, linear, with apices rostrate, obtuse,
+  sometimes slightly capitate; pseudoraphe distinct; striæ about 20 in 10 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p>Pl. <a href="#plate10"><b>10</b></a>, Figs. 32 and 33.</p>
+
+  <p>There is difficulty in recognizing S. radians K. as described and figured by different authors.
+  On Plate <a href="#plate12"><b>12</b></a>, Fig. 8, I have drawn a specimen from H. L. Smith's Type
+  Slide No. 574, labelled S. radians Kuetz., not Wm. Smith, which, however, corresponds closely to
+  Smith's figure (Brit. Diat. 1, Pl. 11, Fig. 89). De Toni gives S. radians Kuetz. as equivalent to
+  S. tenera Wm. Sm. Van Heurck's figure of S. radians, and also the figure of ulna var., said to be
+  synonymous with H. L. Smith's S. radians, which does not correspond to the specimens on Smith's
+  slide in my possession, are confusing. In Van Heurck's Synopsis the striæ are said to be 16 or 17,
+  while De Toni describes them as subtle and from 17 to 24 in 10 µ. The length is quite
+  variable.</p>
+
+  <p>Several species of Synedra resemble S. radians in the mode of growth, as they are adnate at
+  first, in short bands, the frustules being sessile on other plants or objects, attached at the
+  terminal nodules which, although scarcely visible in most forms, are probably present in all. The
+  frustules are not closely connected at the free end, and soon become entirely detached.</p>
+
+  <p class="sp3">In Diatoma and Fragilaria, we find a punctum or pore at one end of a valve, but not
+  in line with the pseudoraphe; in Synedra, a minute pore is usually found in the position of the
+  terminal nodule and, in some species, indications of a central nodule are observed; the median
+  line is wider but there is no raphe. In the fresh-water Synedræ, many of which are among the
+  longest of diatoms, living in running streams, the terminal nodules are much more indistinct,
+  while the marine forms have distinct terminal nodules, are not, as a rule, found in bands, and
+  assume a more naviculoid outline.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA VAUCHERIÆ VAR. PARVULA
+  (KUETZ.) RAB.</span></p>
+
+  <p>Valve lanceolate, with produced or rostrate apices; pseudo-nodule wide, excentric. L. 17 µ.</p>
+
+  <p>Crum Creek.</p>
+
+  <p>Pl. <a href="#plate12"><b>12</b></a>, Fig. 5.</p>
+
+  <p class="sp3">Fig. 6 represents a variety with coarser striæ from the Schuylkill River. Both are
+  easily mistaken for Fragilaria intermedia.</p>
+
+  <div><span class="pagenum" id="page50">{50}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA FULGENS (GREV.) WM.
+  SM.</span></p>
+
+  <p>Frustules geminate or flabellate on a stipe. Valve slightly inflated in the middle and at the
+  apices; pseudoraphe narrow; striæ finely punctate, radiate at the ends.</p>
+
+  <p>Marine. Atlantic City.</p>
+
+  <p class="sp3">Pl. <a href="#plate11"><b>11</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA AFFINIS KUETZ.</span></p>
+
+  <p>Valve lanceolate; striæ marginal, leaving a broad lanceolate pseudoraphe.</p>
+
+  <p>Common along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA AFFINIS VAR. PARVA
+  (KUETZ.) V. H.</span></p>
+
+  <p>Valve lanceolate, slender; striæ marginal, shorter than in the type.</p>
+
+  <p><i>Synedra gracilis</i> Kuetz.</p>
+
+  <p>Common along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SYNEDRA AFFINIS VAR. TABULATA
+  (AG.) V. H.</span></p>
+
+  <p>Valve linear-lanceolate; striæ, 11 in 10 µ, very short.</p>
+
+  <p>Not common. New Rochelle.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Fig. 4.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Asterionella Hassall</span>
+  (1855)</h4>
+
+  <p class="ac">(dim. of aster, a star)</p>
+
+  <p class="sp3">Frustules linear, slightly inflated at the ends, arranged in star-shaped clusters
+  which soon break up. Valve linear, unequally inflated at the ends.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ASTERIONELLA FORMOSA
+  HASS.</span></p>
+
+  <p>Valve clavate at the ends; striæ transverse, 17 in 10 µ, pseudoraphe very narrow or indistinct;
+  an ovoid, hyaline area at each end.</p>
+
+  <p>Newark, N. J. Broomall's Lake, Media (Palmer).</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Figs. 19, 20, 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ASTERIONELLA INFLATA
+  HEIB.</span></p>
+
+  <p>Valve linear, capitate at each end and tumid in the middle; striæ distinctly punctate;
+  pseudoraphe indistinct, or not apparent. L. 30 µ.</p>
+
+  <p>Fresh water. May's Landing, N. J.</p>
+
+  <p class="sp4">Pl. <a href="#plate12"><b>12</b></a>, Fig. 22.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIINÆ</span></p>
+
+  <p><i>Eunotia.</i>&mdash;Frustules either free, in fasciæ or epiphytic. Valves arcuate.</p>
+
+  <p class="sp3"><i>Actinella.</i>&mdash;Frustules, solitary or in small clusters, cuneate. Valve
+  inflated at one end.</p>
+
+  <div><span class="pagenum" id="page51">{51}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Eunotia Ehr.</span> (1837) em. <span
+  class="sc">Grun.</span> (1862)</h4>
+
+  <p class="ac">(eu, well, and noton, a back, referring to the strong, ridged dorsum)</p>
+
+  <p>Frustules free, in fasciæ or epiphytic. Valve arcuate, without costæ, transversely striated;
+  pseudoraphe absent; pseudo-nodules at each end.</p>
+
+  <p>Chromatophores laminate along the concave zone and the valves.</p>
+
+  <p class="sp3">Very many species of Eunotia have been created to differentiate size and number of
+  crenæ or undulations. An examination of certain fossil deposits of New England, as well as a
+  gathering from the blue clay of Philadelphia, will show forms which vary infinitely. E. major and
+  E. gracilis are scarcely distinguishable because of the intermediate variations. The striæ in all
+  forms are punctate, but the puncta are frequently confluent.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANALYSIS OF SPECIES</span></p>
+
+  <p>Eunotia is divided into two sections, Himantidium and Eunotia proper. In Himantidium, the
+  frustules are in fasciæ, either short or long. Among those with short fasciæ are major, gracilis,
+  and nymanniana; those with long fasciæ are pectinalis, solierolii and veneris. Eunotia proper
+  includes frustules, free or epiphytic, in which the valves are not dentate on the dorsal margin,
+  such as lunaris, hemicyclus, biceps and prærupta; and those in which the valves are dentate or
+  crenate on the dorsum, such as monodon, triodon, diadema and others.</p>
+
+  <p class="sp3">The resemblance between Eunotia and Epithemia is noticeable. In both, the epiphytic
+  character of the valve is seen in the shape of the frustule which is arched, and, in the free
+  forms, is adherent at the ends only. In Epithemia, the median is more evident than the terminal
+  nodules. In Eunotia, there is no median nodule, but the end nodules, in some species, are quite
+  evident, and a tendency is shown to produce a very short raphe. The arrangement of puncta in valve
+  view is similar in both genera.</p>
+
+  <p class="ac"><span class="sc">Section 1. Himantidium</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA MAJOR (WM. SM.)
+  RAB.</span></p>
+
+  <p>Valve arcuate, linear, subcapitate, recurved. Striæ punctate, 12 in 10 µ L. 90-190 µ.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Figs. 1 and 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA GRACILIS (EHR.)
+  RAB.</span></p>
+
+  <p>Valve with sides parallel; apices slightly capitate and revolute; striæ, 10 in 10 µ. The striæ
+  on the connective membrane more delicate than in E. major. Intermediate forms occur.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 3. Fig. 4 is indeterminate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA NYMANNIANA
+  GRUN.</span></p>
+
+  <p>Valve small, curved, with parallel dorsal and ventral margins; apices truncate and recurved
+  into dorsal elevations; striæ delicate.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 32.</p>
+
+  <div><span class="pagenum" id="page52">{52}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA PECTINALIS
+  (KUETZ.)</span></p>
+
+  <p>Valve linear, arcuate, apices slightly rostrate; striæ distinctly punctate with puncta in
+  longitudinal rows nearer together at the ends.</p>
+
+  <p><i>Himantidium pectinale</i> Kuetz.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p>Pl. <a href="#plate13"><b>13</b></a>, Figs. 6 and 7.</p>
+
+  <p>The fasciæ are associated in large masses, sometimes an inch or more in diameter, and late in
+  August are found a foot or more in length, of a beautiful chocolate color. Exceedingly abundant in
+  the cedar-swamp streams of the Pine Barren regions of New Jersey. In winter, the dead frustules
+  form a parchment-like coating upon the twigs, dead leaves, and other débris on the borders of
+  streams.</p>
+
+  <p class="sp3">This species can scarcely be referred to Dillwyn's Conferva pectinalis, as, in his
+  description, quoting Mueller, he says that "the filaments are of a dirty green color; seldom
+  exceeding half an inch in length." Dillwyn's form is probably Fragilaria virescens, which equals
+  Fragilaria pectinalis Ehr., while Kuetzing's species is Fragilaria pectinalis Ralfs. It is not
+  impossible to confuse Fragilaria virescens and Eunotia pectinalis when the zone only is seen under
+  a low power and their mode of growth is similar.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA PECTINALIS VAR. UNDULATA
+  RALFS</span></p>
+
+  <p>Valve as in type form, but with undulate margins.</p>
+
+  <p>Common in the cedar swamps of New Jersey.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Figs. 8 and 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA PECTINALIS VAR.
+  SOLIEROLII (KUETZ.)</span></p>
+
+  <p>Valve as in type, but with internal divisions as though in the process of reduplication.</p>
+
+  <p>Not common. Moorestown, N. J. (Palmer).</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA PECTINALIS VAR.
+  VENTRICOSA GRUN.</span></p>
+
+  <p>As in type, but with the valves tumid in the middle.</p>
+
+  <p>May's Landing, N. J.</p>
+
+  <p>Pl. <a href="#plate13"><b>13</b></a>, Fig. 12.</p>
+
+  <p class="sp3">Fig. 11 is a form found in the blue clay. It differs in the coarser puncta from the
+  var. ventricosa. In outline it resembles Eunotia arcus Wm. Sm., which is Ceratoneis arcus (Ehr.)
+  Kuetz., but the central nodule is not present as in the latter form, which connects Eunotia and
+  Cymbella. It may be a form of E. luna Ehr. (A. S., Atlas, Pl. 286, Figs. 33 and 34.)</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA VENERIS KUETZ.</span></p>
+
+  <p>Valve with convex dorsal and straight ventral margins, more or less constricted near the
+  sub-acute apices. Striæ subtle, punctate.</p>
+
+  <p><i>Eunotia incisa</i> Greg.</p>
+
+  <p>May's Landing, N. J. Blue clay, Pavonia, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Figs. 30 and 31.</p>
+
+  <div><span class="pagenum" id="page53">{53}</span></div>
+
+  <p class="ac"><span class="sc">Eunotia (proper)</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA LUNARIS (EHR.)
+  GRUN.</span></p>
+
+  <p>Frustules sessile, solitary or in clusters. Valve arcuate, narrow, attenuated toward the
+  apices, which are sometimes slightly rostrate or rostrate-capitate; transverse striæ, 14 in 10 µ,
+  punctate.</p>
+
+  <p>Very common in ditches, especially in the spring. Variable in length.</p>
+
+  <p class="sp3">Pl. <a href="#plate12"><b>12</b></a>, Figs. 24 and 25.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA HEMICYCLUS (EHR.)
+  RALFS</span></p>
+
+  <p>Valve semicircular, with obtuse apices; striæ transverse, punctate; terminal nodules minute and
+  indistinct.</p>
+
+  <p>Hammonton Pond, N. J. Rare.</p>
+
+  <p>Pl. <a href="#plate12"><b>12</b></a>, Fig. 23.</p>
+
+  <p class="sp3">The genus Pseudo-Eunotia was created by Grunow for forms like Eunotia, but without
+  terminal nodules. As, however, in E. lunaris and E. hemicyclus nodules are evident, although not
+  so large as in many species, I include these two forms as heretofore under Eunotia.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA BICEPS EHR.</span></p>
+
+  <p>Valve linear, slightly arcuate, narrow, with rounded apices somewhat revolute; striæ, 16 in 10
+  µ.</p>
+
+  <p>May's Landing, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 27.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA PRÆRUPTA EHR.</span></p>
+
+  <p>Valve convex on dorsal side, apices dilated and truncate; striæ distant at centre.</p>
+
+  <p>Common in the blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA PRÆRUPTA VAR. BIDENS
+  GRUN.</span></p>
+
+  <p>Valve with two undulations; otherwise as in type.</p>
+
+  <p><i>Eunotia bigibba</i> Greg.</p>
+
+  <p>With the type.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA ROBUSTA RALFS</span></p>
+
+  <p>Valve arcuate, with several or numerous dorsal ridges or crenæ which decrease in relative size
+  in proportion to their number. Striæ radiate, variable in distance apart, and in size of
+  puncta.</p>
+
+  <p>Ralfs included under this one name the following species named by Ehrenberg: E. diodon (2
+  crenæ); E. triodon (3); E. tetraodon (4); E. pentodon (5); E. diadema (6); E. heptodon (7); E.
+  octodon (8); E. enneadon (9); E. decadon (10); E. hendecadon (11); E. duodecadon (12); E. serra
+  (13); E. prioritis (14); all more than 20, E. polyodon. E. scalaris, with from 15 to 17 crenæ, and
+  E. icosodon with 20, may be added.</p>
+
+  <p>It is probable that all of these forms occur at May's Landing, N. J. The forms with more than
+  eight crenæ are comparatively rare. In the blue clay those with from four to six are most
+  common.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Figs. 13, 14, 15, 16, 17, 21, 24, 25.</p>
+
+  <div><span class="pagenum" id="page54">{54}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA BACTRIANA EHR.</span></p>
+
+  <p>Valve linear, apices revolute, acute, dentate on the dorsal margin, with one acute crena near
+  each end.</p>
+
+  <p>Tom's River, N. J. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA BIDENTULA WM.
+  SM.</span></p>
+
+  <p>Valve with straight ventral margin, and with two undulations on the dorsum; apices large,
+  rounded.</p>
+
+  <p>May's Landing, N. J. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate13"><b>13</b></a>, Fig. 20 (not Schumann's form, which has
+  angular crenæ).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EUNOTIA FORMICA EHR.
+  VAR.?</span></p>
+
+  <p>Valve turgid in the middle and at the apices which are unilaterally truncate.</p>
+
+  <p>Pensauken, N. J. (artesian well).</p>
+
+  <p>Pl. <a href="#plate13"><b>13</b></a>, Fig. 26 (not a typical form).</p>
+
+  <p>The following are forms which appear to be indeterminate, or, in any case, are scarcely worthy
+  of distinction by specific names, as might be said of others of the innumerable variations of this
+  genus:</p>
+
+  <p>Fig. 23, Pl. <a href="#plate13"><b>13</b></a>, probably a form of prærupta. Newtown Square.</p>
+
+  <p>Fig. 28, Pl. <a href="#plate13"><b>13</b></a>, from the blue clay.</p>
+
+  <p>Fig. 29, Pl. <a href="#plate13"><b>13</b></a>, an asymmetrical form, apparently abnormal, but
+  not rare at May's Landing, N. J.</p>
+
+  <p>Fig. 17, Pl. <a href="#plate38"><b>38</b></a>. Valve convex on the dorsal side, incised on the
+  ventral; striæ about 15 in 10 µ, closer at the ends; L. 30 µ. Schuylkill River.</p>
+
+  <p>Fig. 18, Pl. <a href="#plate38"><b>38</b></a>. Valve arcuate, asymmetrical, broader at one end;
+  terminal nodules large; striæ, 10 in 10 µ; L. 47 µ. Gloucester, N. J., artesian well.</p>
+
+  <p class="sp3">Numerous variations of the above species are illustrated in Schmidt (Atlas, Pls.
+  285-291).</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Actinella Lewis</span> (1865)</h4>
+
+  <p class="ac">(dim. of actin, a ray)</p>
+
+  <p class="sp3">Frustules solitary, or in small clusters, sub-cuneate or nearly linear. Valve
+  arcuate, rounded at one end and suddenly widened at the other into a cup-shaped or lychnoid
+  inflation.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACTINELLA PUNCTATA
+  LEWIS</span></p>
+
+  <p>Valve with fine, transverse striæ; on the margin, puncta at intervals; terminal nodules
+  distinct.</p>
+
+  <p>May's Landing, N. J.</p>
+
+  <p>Pl. <a href="#plate12"><b>12</b></a>, Figs. 16, 17, 18.</p>
+
+  <p>Fig. 17, from Tom's River, N. J., is an approach toward A. brasiliensis Grun.</p>
+
+  <p class="sp4">Fig. 18 represents the frustules geminate, a frequent occurrence.</p>
+
+  <div><span class="pagenum" id="page55">{55}</span></div>
+
+  <h2>NAVICULOIDEÆ</h2>
+
+  <p>In discussing the Naviculoid group, the general divisions of Cleve are here followed, and all
+  diatoms having a true raphe are included. I have added the genus Epithemia and also Rhopalodia,
+  partly because they contain a raphe of a certain kind and partly because they resemble the
+  markings of certain of the genus Hantzschia in the following group, although in other respects
+  there is probably no similarity.</p>
+
+  <p class="sp3">The difficulty of combining the numerous genera into groups which are naturally
+  affiliated is avoided in the following arrangement based on superficial similarities, and is
+  intended merely as an artificial key. To unite all forms having a raphe and which are symmetrical
+  with valves similar and not sigmoid, under the one genus Navicula, as has been the custom previous
+  to the publication of Cleve's monograph, would result in associating species differing in so many
+  respects in relation to structure of the valve and cell contents that it seems advisable to retain
+  the new genera, especially as the original genus is likely to be still further reduced when more
+  is known of the structure and life history of the group.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">KEY TO THE GENERA</span></p>
+
+  <table class="sp4 mc w50" title="Genera of Naviculoideae" summary="Genera of Naviculoideae">
+    <tr>
+      <td colspan="2" class="ac pb05">Valves dissimilar. Achnantheæ</td>
+    </tr>
+    <tr class="pb05">
+      <td class="itp05">symmetrical</td>
+      <td class="vbm">Cocconeis</td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="2">asymmetrical</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">to the longitudinal axis</td>
+      <td class="vbm">Anorthoneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">to the transverse axis</td>
+      <td class="vbm">Rhoicosphenia</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">in zone view</td>
+      <td class="vbm">Achnanthes</td>
+    </tr>
+    <tr>
+      <td colspan="2" class="ac pt05 pb05">Valves similar and asymmetrical</td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="2">asymmetrical to the longitudinal axis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">valves parallel</td>
+      <td class="vbm">Cymbella</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">valves not parallel</td>
+      <td class="vbm">Amphora</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">valves keeled, twisted (sometimes symmetrical)</td>
+      <td class="vbm">Amphiprora</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">valves keeled</td>
+      <td class="vbm">Tropidoneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">valves reniform and keeled</td>
+      <td class="vbm">Auricula</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">median line sigmoid at the ends</td>
+      <td class="vbm">Scoliotropis</td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="2">asymmetrical to the transverse axis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate and costate</td>
+      <td class="vbm">Gomphoneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate</td>
+      <td class="vbm">Gomphonema</td>
+    </tr>
+    <tr>
+      <td colspan="2" class="ac pt05 pb05">Valves similar, symmetrical and sigmoid</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ oblique</td>
+      <td class="vbm">Pleurosigma</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ at right angles</td>
+      <td class="vbm">Gyrosigma</td>
+    </tr>
+    <tr>
+      <td colspan="2" class="ac pt05 pb05">Valves similar, symmetrical, not sigmoid</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate, nodules elongated</td>
+      <td class="vbm">Frustulia</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ subtly punctate, central nodule forked</td>
+      <td class="vbm">Amphipleura</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate and reticulate, in two strata</td>
+      <td class="vbm">Dictyoneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate and alveolate, in three strata</td>
+      <td class="vbm">Trachyneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate, in two strata</td>
+      <td class="vbm">Brèbissonia</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ interrupted by blank lines</td>
+      <td class="vbm">Anom&#x0153;oneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="pagenum" id="page56">{56}</span>
+        <p class="sp0">striæ crossed by longitudinal lines</p>
+      </td>
+      <td class="vbm">Caloneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ oblique, median fissures in opposite directions</td>
+      <td class="vbm">Neidium</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate and costate, median line with horns</td>
+      <td class="vbm">Diploneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate; valves separated by septate plates</td>
+      <td class="vbm">Mastogloia</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate, central area dilated into a stauros</td>
+      <td class="vbm">Stauroneis</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ punctate, area without stauros or horns</td>
+      <td class="vbm">Navicula</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">striæ costate, not punctate</td>
+      <td class="vbm">Pinnularia</td>
+    </tr>
+  </table>
+
+  <h3>ACHNANTHEÆ</h3>
+
+  <p>Frustules stipitate, free or parasitic. Valves cuneate, elliptical or suborbicular, dissimilar,
+  bent along the transverse or the longitudinal axes, the lower valve with a true raphe and central
+  and terminal nodules, the upper valve with a pseudoraphe or median line.</p>
+
+  <p><i>Rhoicosphenia.</i>&mdash;Stipitate; valves with transverse puncta, bent along the transverse
+  axis, cuneate, with diaphragms at the ends.</p>
+
+  <p><i>Anorthoneis.</i>&mdash;Free; puncta radiate; valves bent slightly along the transverse axis,
+  suborbicular.</p>
+
+  <p><i>Cocconeis.</i>&mdash;Parasitic; valves elliptical, usually bent along the longitudinal axis;
+  striæ punctate, transverse and longitudinal.</p>
+
+  <p class="sp3"><i>Achnanthes.</i>&mdash;Stipitate; valves lanceolate or elliptical, bent along the
+  transverse axis; striæ transverse, punctate; costæ sometimes present.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Rhoicosphenia</span> <span
+  class="smaller">GRUN.</span> (1860)</h4>
+
+  <p class="ac">(rhoicos, curved, and sphen, a wedge)</p>
+
+  <p>Frustule in zone view curved; valves cuneate, dissimilar, the upper with a pseudoraphe, the
+  lower with a raphe.</p>
+
+  <p class="sp3">Chromatophore a single plate along both valves, and one of the inner walls of the
+  zone. Conjugation as in Gomphonema, with which it is generally associated in classification.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHOICOSPHENIA CURVATA (KUETZ.)
+  GRUN.</span></p>
+
+  <p>Valve clavate, with rounded apex and base; lower valve with raphe, a narrow axial area and
+  slightly radiate, punctate striæ; the upper valve with a narrow pseudoraphe and parallel striæ; a
+  short diaphragm at the ends of each valve. Length usually from 15 to 25 µ, but frequently of twice
+  the size.</p>
+
+  <p>Common in Crum Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Figs. 25, 26, 27.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Anorthoneis</span> <span
+  class="smaller">GRUN.</span> (1868)</h4>
+
+  <p class="ac">(anorthos, not straight)</p>
+
+  <p class="sp3">Valves dissimilar, the upper valve with an excentric axial area, the lower with an
+  excentric raphe.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANORTHONEIS EXCENTRICA (DONK.)
+  GRUN.</span></p>
+
+  <p>Valves orbicular, with radiating, punctate striæ, closer at the circumference, producing the
+  appearance of a border. Axial area not reaching the ends. Frustules occur free on the sands of the
+  sea-shore. L. 25 to 50 µ.</p>
+
+  <p>Belmar, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Figs. 30 and 31.</p>
+
+  <div><span class="pagenum" id="page57">{57}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Cocconeis</span> <span
+  class="smaller">EHR.</span> (1835) em. <span class="smaller">GRUN.</span> (1868)</h4>
+
+  <p class="ac">(coccos, a berry)</p>
+
+  <p>Valves elliptical, dissimilar, the upper valve with a pseudoraphe and the lower with a genuine
+  raphe and nodules, usually with a rim or annulus. Frustules epiphytic.</p>
+
+  <p>Cocconeis is generally considered as a degenerated form of Mastogloia, as indicated by the
+  "obsoletely loculiferous rim." The frustules are usually bent along the longitudinal axis,
+  probably because of the attachment to the curved stems of water-plants.</p>
+
+  <p>The cell contents of only a few species are known. In C. pediculus, a single chromatophore
+  occurs on the inside of the upper valve. In conjugation, two cells open and secrete a gelatinous
+  mass from which an auxospore is formed.</p>
+
+  <p class="sp3">Cleve separates the forms having a loculiferous rim (Cocconeis) from those without
+  a rim (Eucocconeis). As the rim is easily detachable, the distinction is often made with
+  difficulty.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COCCONEIS SCUTELLUM
+  EHR.</span></p>
+
+  <p>Valves elliptical, the upper with a linear or lanceolate pseudoraphe and coarse puncta in
+  transverse and radiating lines; the lower valve with much finer puncta in radiating lines, a
+  lanceolate axial area and, sometimes, a loculiferous rim.</p>
+
+  <p>Along the coast. Common, but extremely variable.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Fig. 21 (upper valve). Fig. 18, var. ?</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COCCONEIS SCUTELLUM VAR. ORNATA
+  GRUN.</span></p>
+
+  <p>Upper valve with linear axial area, and transverse and radiating punctate lines which end at
+  the border in a double row of finer puncta; lower valve with much finer puncta, a lanceolate axial
+  area and a loculiferous rim.</p>
+
+  <p>Atlantic City. Common.</p>
+
+  <p>Pl. <a href="#plate16"><b>16</b></a>, Figs. 27 and 28.</p>
+
+  <p class="sp3">The forms along the coast vary infinitely both in size and appearance. The var.
+  ornata is very abundant along the entire coast. In any gathering, valves are found with or without
+  the rim which is frequently seen detached. The upper valve is sometimes without the double row of
+  puncta. Fig. 21 represents an upper valve more coarsely punctate than usually occurs. Very many
+  intermediate forms might be noticed.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COCCONEIS PEDICULUS
+  EHR.</span></p>
+
+  <p>Valves rhombic-elliptical, very convex, somewhat asymmetrical; the upper valve with a linear
+  pseudoraphe, sometimes widened near the ends, and slightly radiating, finely punctate striæ; lower
+  valve with narrow, axial area and finely punctate, radiating striæ.</p>
+
+  <p>Not uncommon in fresh water. Abundant in a ditch at Paoli, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Figs. 23 and 24.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COCCONEIS PLACENTULA
+  EHR.</span></p>
+
+  <p>Valve elliptical; upper valve with a linear or lanceolate axial area, and punctate striæ in
+  transverse and radiating rows, the puncta at equal distances; the lower valve with a lanceolate
+  axial area, radiating rows of puncta, and a wide border of finely punctate, radiating striæ,
+  separated from the central part of the valve by a narrow hyaline zone.</p>
+
+  <p>Common in salt, brackish and fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Figs. 19 and 20.</p>
+
+  <div><span class="pagenum" id="page58">{58}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COCCONEIS PLACENTULA VAR. LINEATA
+  (EHR.) V. H.</span></p>
+
+  <p>As in the type, except that the upper valve has the puncta arranged in zig-zag, giving the
+  appearance of sinuous, longitudinal lines.</p>
+
+  <p>Common along the coast.</p>
+
+  <p>Pl. <a href="#plate16"><b>16</b></a>, Fig. 29.</p>
+
+  <p>C. pediculus and C. placentula are the only species I have found in fresh water. Cleve states
+  that the former occurs also in brackish water.</p>
+
+  <p class="sp3">The following are among the species placed by Cleve in a new genus, Eucocconeis,
+  distinguished by the absence of a loculiferous rim.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COCCONEIS DIRUPTA
+  GREG.</span></p>
+
+  <p>Valves elliptical, the lower with fine puncta in slightly radiating lines, a narrow axial area
+  and a central area dilated into a lanceolate, stauriform space; the terminal fissures turned in
+  opposite directions; the upper valve similar to the lower valve except in the absence of raphe and
+  nodules.</p>
+
+  <p>Along the coast. New Rochelle.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Fig. 22 (lower valve).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">COCCONEIS PELLUCIDA
+  GRUN.</span></p>
+
+  <p>Valves elliptical, the upper with broad axial area on each side of which are fine, longitudinal
+  rows of short striæ; the lower valve with more numerous longitudinal rows, a marginal line and
+  indistinct raphe; the terminal fissures small and turned in opposite directions.</p>
+
+  <p>New Rochelle.</p>
+
+  <p>Pl. <a href="#plate16"><b>16</b></a>, Figs. 25 and 26.</p>
+
+  <p class="sp3">In the var. minor Grun. the median line of the lower valve is sometimes slightly
+  sigmoid.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Achnanthes</span> <span
+  class="smaller">BORY</span> (1822)</h4>
+
+  <p class="ac">(achne, froth or down, and anthos, a flower)</p>
+
+  <p>Frustules stipitate, solitary or in short fasciæ, flexed. Valves elliptical or lanceolate,
+  naviculoid, dissimilar, the lower with a raphe and median and terminal nodules, and the upper with
+  a pseudoraphe or median space.</p>
+
+  <p class="sp3">The genus has no apparent affinity with any other.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES LONGIPES
+  AG.</span></p>
+
+  <p>Valves linear-elliptical, obtuse at the apex, sometimes slightly constricted in the middle.
+  Connective zone with transverse, subtly punctate striæ, interrupted by longitudinal lines. Central
+  nodule of lower valve dilated into a stauros reaching the margin. Valves costate, the costæ
+  alternating with double rows of fine puncta.</p>
+
+  <p>Along the coast, in estuaries.</p>
+
+  <p>Pl. <a href="#plate16"><b>16</b></a>, Figs. 1 and 2.</p>
+
+  <p>A. longipes is the only species in our locality considered by Cleve as belonging to the genus;
+  the other forms, distinguished by the absence of costæ, are included in the genus Achnanthidium of
+  Kuetzing.</p>
+
+  <p class="sp3">In A. longipes, the chromatophores consist of scattered, rounded granules, while in
+  Achnanthidium the chromatophore is a single plate along the upper valve, or a double one <span
+  class="pagenum" id="page59">{59}</span>along the connective zone. It is necessary, therefore, to
+  distinguish between A. longipes and the following group, but, because of the long continued union
+  of all of the stipitate forms having the general appearance of a true Achnanthes, I shall continue
+  to describe the local species under the generally accepted name.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES BREVIPES
+  AG.</span></p>
+
+  <p>Valves without costæ; striæ moniliform; upper valve with excentric pseudoraphe or median line;
+  otherwise as in A. longipes.</p>
+
+  <p>Along the coast, in estuaries.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES SUBSESSILIS
+  KUETZ.</span></p>
+
+  <p>Valves linear-elliptical, rounded at the ends; upper valve with excentric pseudoraphe; striæ
+  moniliform, puncta smaller than in A. brevipes.</p>
+
+  <p>Along the coast, in estuaries.</p>
+
+  <p>Pl. <a href="#plate16"><b>16</b></a>, Figs. 4, 5, 6.</p>
+
+  <p class="sp3">The three species described above are named from the length of the stipe, but this
+  varies considerably and is not of special significance.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES INFLATA (KUETZ.)
+  GRUN.</span></p>
+
+  <p>Valves more or less inflated in the middle, usually with the stauros of the lower valve
+  asymmetrical and wider than in A. subsessilis, with which it agrees in size and markings.</p>
+
+  <p>Gloucester, N. J. (artesian well).</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Figs. 7 and 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES COARCTATA (BRÉB.)
+  GRUN.</span></p>
+
+  <p>Valves lanceolate, oblong, broad at the ends and constricted in the middle. Stauros wide;
+  pseudoraphe of the upper valve excentric; striæ slightly radiate on the lower valve; puncta
+  small.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES LANCEOLATA (BRÉB.)
+  GRUN.</span></p>
+
+  <p>Valves more or less elliptical; striæ radiating, 12 in 10 µ, punctate; on the lower valve a
+  horse-shoe shaped hyaline space on one side of the centre; on the upper valve an irregular
+  stauros, not reaching the margin. L. 8-20 µ.</p>
+
+  <p>In springs. Abundant at Newtown Square.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Figs. 10, 11, 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES EXIGUA
+  GRUN.</span></p>
+
+  <p>Valves oblong-lanceolate, with rostrate ends, sometimes slightly constricted in the middle.
+  Stauros rather wide; striæ punctate, radiating, 22 in 10 µ. L. 10-12 µ.</p>
+
+  <p><i>Stauroneis exilis</i> Kuetz. (not Achnanthes exilis Kuetz.)</p>
+
+  <p>Frequently found in aquaria where I have kept it growing continuously for years.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Figs. 14 and 15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES LINEARIS FORMA CURTA
+  H. L. SMITH</span></p>
+
+  <p>Frustules solitary or geminate. Valves linear-elliptical, or elliptical-lanceolate. Lower valve
+  without distinct axial area; upper valve with axial area widened in the middle; striæ slightly
+  radiate (?). L. 7 µ. One of the smallest of diatoms.</p>
+
+  <div><span class="pagenum" id="page60">{60}</span></div>
+
+  <p>This form I found in a pure gathering covering the sides of a greenhouse tank at Elm, N. J. It
+  was sent to Prof. H. L. Smith, who determined it as forma curta of A. linearis.</p>
+
+  <p class="sp3">Pl. <a href="#plate16"><b>16</b></a>, Figs. 16 and 17.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ACHNANTHES DANICA (FLOEGEL)
+  GRUN.</span></p>
+
+  <p>Valves rhombic-lanceolate, with subacute ends. Striæ, 25 in 10 µ, radiate. Lower valve with
+  stauros widened toward the margin, and cleft into three divisions.</p>
+
+  <p>Pavonia, N. J. (artesian well).</p>
+
+  <p>Pl. <a href="#plate16"><b>16</b></a>, Fig. 13.</p>
+
+  <p class="sp3">I have seen the lower valve only. Cleve states that the upper valve is costate with
+  "alternating fine lineolæ twice as close as the costæ."</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Cymbella</span> <span
+  class="smaller">AG. </span> (1830)</h4>
+
+  <p class="ac">(cymbe, a boat)</p>
+
+  <p>Frustules free, stipitate or enclosed in tubes. Valve boat-shaped; median line asymmetrical,
+  straight or curved.</p>
+
+  <p>Chromatophore single, covering the entire interior of the frustule, except the ventral part of
+  the zone and the median lines. Its longitudinal axis is on the dorsal part of the zone. A pyrenoid
+  lies in a fold of the chromatophore on the dorsal part.</p>
+
+  <p class="sp3">The genus includes the former genera of Cocconema, characterized by stipitate
+  forms, and Encyonema in which the frustules are frequently enclosed in gelatinous tubes.</p>
+
+  <p class="ac"><span class="sc">Section 1.&mdash;Cymbella Proper. Frustules free or sometimes
+  stipitate</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA HETEROPLEURA (EHR.)
+  KUETZ.</span></p>
+
+  <p>Valve nearly symmetrical, lanceolate, with rostrate, produced apices; median line nearly
+  straight; axial area linear, widened in the middle; striæ radiate, punctate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA CUSPIDATA
+  KUETZ.</span></p>
+
+  <p>Valve broad, elliptical, with rostrate, somewhat acute, apices and nearly straight, ventral
+  margin; median line straight, axial area linear, widened in the middle; striæ radiate,
+  punctate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 17.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA NAVICULIFORMIS
+  AUERSWALD</span></p>
+
+  <p>Valve linear-elliptical, with abruptly produced apices; ventral margin straight; median line
+  almost straight; axial area narrow, central area large, rounded; striæ distant in the middle,
+  closer at the ends.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA EHRENBERGII
+  KUETZ.</span></p>
+
+  <p>Valve lanceolate, with ventral margin nearly straight and apices sub-rostrate; median line
+  straight, excentric; axial area narrow; central area widened in the middle; striæ coarsely
+  punctate.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 9.</p>
+
+  <div><span class="pagenum" id="page61">{61}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA AFFINIS
+  KUETZ.</span></p>
+
+  <p>Valve about three times as long as broad, strongly convex on the dorsal side and straight on
+  the ventral; apices sub-rostrate; striæ punctate; axial area narrow, not widened in the middle;
+  median line curved; a small or indistinct punctum on the ventral side of the median line (not
+  shown in the figure).</p>
+
+  <p>Common in ponds. Abundant in East Park Reservoir.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA EXCISA (KUETZ.) DE
+  TONI</span></p>
+
+  <p>Valve as in affinis, but with tumid and excised ventral margin; a punctum is found on the
+  ventral side (not shown in the figure).</p>
+
+  <p>According to Cleve this is a variety of C. affinis.</p>
+
+  <p>Common in ponds.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Figs. 15, 19?</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA PARVA (WM. SM.)
+  CL.</span></p>
+
+  <p>Valve semi-lanceolate, with produced apices; ventral margin slightly tumid; axial area narrow;
+  striæ coarsely but obscurely punctate.</p>
+
+  <p>C. affinis and C. parva are quite variable, the latter differing by its lanceolate form and the
+  absence of a punctum, which, however, is sometimes difficult to recognize. In a gathering of C.
+  parva, it is quite possible to find numerous abnormal forms which appear to be sporangial, so that
+  specific distinctions are difficult if based on occasional specimens.</p>
+
+  <p>Common in ponds.</p>
+
+  <p class="sp3">Pl. <a href="#plate38"><b>38</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA AMPHICEPHALA
+  NÆGELI</span></p>
+
+  <p>Valve unequally elliptical, with broad, rostrate apices; axial area narrow; median line
+  straight; central area small, rounded; striæ, 12 in 10 µ on the dorsal, closer on the ventral,
+  side and at the ends.</p>
+
+  <p>Kirkwood Pond, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA SINUATA GREG.</span></p>
+
+  <p>Valve linear-elliptical, gibbous on the ventral side; axial area indistinct; central area
+  widened on the ventral side nearly to the margin.</p>
+
+  <p>Crum Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 13.</p>
+
+  <p class="ac"><span class="sc">Section 2.&mdash;Cocconema. Frustules stipitate</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA ASPERA (EHR.)
+  CL.</span></p>
+
+  <p>Valve large, cymbiform, arcuate on the dorsal, slightly gibbous on the ventral side; axial area
+  linear, broad, slightly widened in the middle; no row of puncta on the ventral side. The puncta
+  form curved longitudinal lines and the innermost row on the ventral side appears sometimes distant
+  from the others, but not as in C. cistula.</p>
+
+  <p><i>Cocconema asperum</i> Ehr.</p>
+
+  <p><i>Cymbella gastroides</i> Kuetz.</p>
+
+  <div><span class="pagenum" id="page62">{62}</span></div>
+
+  <p>Not Cymbella gastroides H. L. Smith, Type No. 118, which is C. mexicana A. S., having a punctum
+  in the middle of the central nodule; in outline it is like C. gastroides var. minor Kuetz.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 1 (an unusual form, but it resembles
+  Grunow's. (Diat. Franz Jos. Land, Pl. 1, Fig. 7.)</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA CYMBIFORMIS (KUETZ.)
+  BRÉB.</span></p>
+
+  <p>Valve cymbiform, slightly gibbous on the ventral margin; apices broad, somewhat truncate; a
+  punctum occurs on the ventral side of the median line; striæ, 8 in 10 µ, closely punctate.</p>
+
+  <p>Kirkwood Pond, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA CISTULA (HEMPR.)
+  KIRCHN.</span></p>
+
+  <p>Valve cymbiform, with gibbous ventral margin and truncate apices; a distinct row of several
+  puncta occurs below the median line in typical forms.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA LANCEOLATA (EHR.)
+  KIRCHN.</span></p>
+
+  <p>Valve cymbiform, with gibbous ventral margin; apices truncate; axial area very narrow, scarcely
+  widened in the middle; striæ with fine close puncta.</p>
+
+  <p>Kirkwood Pond, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA MEXICANA (EHR.) A.
+  S.</span></p>
+
+  <p>Valve broad, with gibbous ventral margin and sub-rostrate, truncate apices; median line with
+  reflexed terminal fissures; striæ with coarse puncta; a large punctum occurs in the centre of the
+  central area.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA TUMIDA (BRÉB.) V.
+  H.</span></p>
+
+  <p>Valve cymbiform, with gibbous ventral margin and abruptly rostrate ends; median line arcuate;
+  axial area narrow; central area large, orbicular; below the central nodule is a punctum; striæ
+  punctate.</p>
+
+  <p>Crum Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 7.</p>
+
+  <p class="ac"><span class="sc">Section 3.&mdash;Encyonema. Frustules in tubes</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA VENTRICOSA
+  KUETZ.</span></p>
+
+  <p>Valve lunate, with straight or slightly gibbous ventral margin; axial area indistinct; median
+  line straight or nearly so; striæ punctate.</p>
+
+  <p>Very common, but extremely variable. The ventral margin is sometimes straight and sometimes
+  quite gibbous.</p>
+
+  <p>Pl. <a href="#plate18"><b>18</b></a>, Figs. 14, 22; Pl. <a href="#plate38"><b>38</b></a>, Fig.
+  16; Pl. <a href="#plate40"><b>40</b></a>, Fig. 8.</p>
+
+  <div><span class="pagenum" id="page63">{63}</span></div>
+
+  <p class="sp3">C. ventricosa is considered by some authors to be equivalent to C. affinis var.
+  semicircularis Lagerst., Encyonema prostratum (Berk.) Ralfs, E. cæspitosum Kuetz. and E.
+  auerswaldii Rab. H. L. Smith's Type Slide of C. ventricosa Ag. is said to equal C. affinis Kuetz.,
+  but the specimens appear to me to be equivalent to C. ventricosa Kuetz. Cleve unites many forms,
+  including E. cæspitosum, under C. ventricosa.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA PROSTRATA (BERK.)
+  CL.</span></p>
+
+  <p>Valve semi-elliptical, obtuse at the apices, which are sometimes prolonged and turned
+  downwards; median line straight, terminal nodules distant from the ends; axial area narrow,
+  central area rounded; striæ in radiating, slightly curved lines, indistinctly punctate.</p>
+
+  <p>Common in fresh water; occasional in brackish.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 21 (represents a frequent
+  variation).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA PHILADELPHICA N.
+  SP.</span></p>
+
+  <p>Valve semi-elliptical-lanceolate, with rounded apices; ventral margin strongly gibbous;
+  terminal nodules distant from the ends; axial area broad, central area widened on the dorsal side;
+  striæ radiate, not curved nor of unequal length, indistinctly punctate, 10 in 10 µ on the dorsal,
+  8 in 10 µ on the ventral side. L. 86 µ.</p>
+
+  <p>This form approaches Encyonema prostratum (Berk.) Ralfs, Schmidt's Atlas, Pl. 71, Fig. 7, but
+  differs in the striæ and the axial and central areas.</p>
+
+  <p>Blue clay of Philadelphia. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA TRIANGULUM (EHR.)
+  CL.</span></p>
+
+  <p>Valve semi-elliptical, with acute ends; median line straight; ventral side half the width of
+  the dorsal, with straight, slightly convex or concave margin; striæ radiate, coarsely
+  punctate.</p>
+
+  <p><i>Gl&#x0153;onema triangulum</i> Ehr.</p>
+
+  <p>Baker's Run, Willistown, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 24.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA TURGIDA (GREG.)
+  CL.</span></p>
+
+  <p>Valve semi-elliptical, with acute ends; ventral margin gibbous; ventral side half the width of
+  the dorsal; median line straight; terminal fissures turned downwards; axial area broad; striæ
+  radiate, coarsely punctate.</p>
+
+  <p>Baker's Run, Willistown, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA TURGIDA (GREG.) CL. VAR.
+  ?</span></p>
+
+  <p>Valve lunate, with gibbous ventral margin; median line straight; terminal fissures turned
+  downwards near the ends; axial area lanceolate, striæ radiate on the dorsal side, 8 in 10 µ,
+  punctate, 9 on the ventral side, closer at the ends where they are convergent. L. 65 µ. Not a
+  typical form.</p>
+
+  <p>Willistown, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA RHOMBOIDEA N.
+  SP.</span></p>
+
+  <p>Valve rhomboidal, with acute ends; dorsal part one and a half times the width of the ventral;
+  median line nearly straight, with terminal fissures turned downwards near the ends; axial area
+  broad, not widened in the middle, except slightly on the ventral side; striæ <span class="pagenum"
+  id="page64">{64}</span>radiate, distant in the middle of the dorsal side where they are 7 in 10 µ,
+  coarsely punctate, the puncta in longitudinal lines, 9 in 10 µ on the ventral side, closer at the
+  ends. L. 69 µ.</p>
+
+  <p>Baker's Run, Willistown, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA GRACILIS (RAB.)
+  CL.</span></p>
+
+  <p>Valve semi-lanceolate, with acute ends; median line nearly straight, with terminal fissures
+  turned downwards, distant from the ends; axial area linear; ventral margin straight or slightly
+  gibbous in the middle.</p>
+
+  <p>Hammonton Pond, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 20.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMBELLA LACUSTRIS (AG.)
+  CL.</span></p>
+
+  <p>Valve elliptical-lanceolate, with obtuse ends, nearly symmetrical; median line straight,
+  terminal fissures distant from the ends; striæ radiate in the middle, convergent at the ends,
+  coarsely lineate.</p>
+
+  <p>Belmar, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate18"><b>18</b></a>, Fig. 25.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Amphora</span> <span
+  class="smaller">EHR.</span> (1840)</h4>
+
+  <p class="ac">(amphora, a jar)</p>
+
+  <p>Valves asymmetrical along the longitudinal axis, as in Cymbella, but with the plane passing
+  through the dorsal and ventral sides of one valve at an angle with that of the other. As Cleve
+  states, Cymbella and Amphora are forms of Navicula "with both valves similar and asymmetrical
+  along the longitudinal axis," and the difference between Cymbella and Amphora is in the "degree of
+  asymmetry." If, following H. L. Smith's diagrams (Lens, Vol. 2, 1873, p. 66), we assume that the
+  usual form of the valve in Navicula is elliptical or lanceolate, and the zone view is rectangular,
+  we have in Cymbella an arcuate median line and a more or less reniform valve, while the zone view
+  remains rectangular with the valves parallel. Now, if the valves are asymmetrical along the
+  longitudinal axis, and one side of one valve is separated from the corresponding side of the
+  opposite valve by a wider connective zone than is the case on the other side, the transverse
+  section of the frustule will appear cuneate, as in Amphora, and the connective zone will be wider
+  on one side than the other. When, therefore, we examine an entire frustule as it is usually seen,
+  we shall find the two raphes of the valves in focus at the same time on the ventral side, and, by
+  changing the focus, the convex sides of the same valves are seen, the dorsal view with, usually, a
+  wider connective zone. As an illustration, compare Figs. 5 and 6, on Plate <a
+  href="#plate15"><b>15</b></a>, Fig. 6 being the ventral, and Fig. 5 the dorsal view.</p>
+
+  <p>As Amphoræ are epiphytic or parasitic, they are considered, as Cleve remarks, like Achnanthes
+  and Cocconeis, as "degenerated forms."</p>
+
+  <p>Chromatophores usually single, lying on the ventral connective zone. Mereschkowsky describes
+  nine forms.</p>
+
+  <p>Cleve divides the genus into a number of groups as follows:</p>
+
+  <p><i>Amphora proper.</i>&mdash;Connective zone not complex; valves with longitudinal lines on the
+  dorsal side; coarsely punctate or costate.</p>
+
+  <p><i>Diplamphora.</i>&mdash;Zone complex; otherwise as in Amphora.</p>
+
+  <p><i>Halamphora.</i>&mdash;Longitudinal lines absent; frustule elongate, with protracted
+  ends.</p>
+
+  <div><span class="pagenum" id="page65">{65}</span></div>
+
+  <p><i>Oxyamphora.</i>&mdash;Zone complex; longitudinal lines absent; frustule elliptical; valve
+  lunate, with or without a central stauros; striæ punctate.</p>
+
+  <p><i>Amblyamphora.</i>&mdash;Zone complex; frustule rectangular; valve lunate; striæ punctate;
+  axial and central areas indistinct.</p>
+
+  <p><i>Psammamphora.</i>&mdash;Zone not complex; frustule rectangular; central nodule frequently
+  dilated to a stauros; no axial or central area.</p>
+
+  <p class="sp3"><i>Cymbamphora.</i>&mdash;Valve semi-lanceolate; median line straight, approximate
+  to the ventral margin.</p>
+
+  <p class="ac"><span class="sc">Amphora</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA ROBUSTA GREG.</span></p>
+
+  <p>Frustule elliptical, truncate; valve lunate, with straight ventral margin; median line
+  biarcuate; ventral side with coarse, radiate striæ, 6 in 10 µ, on both sides of the median
+  line.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA PROTEUS GREG.</span></p>
+
+  <p>Frustule elliptical, truncate; valve lunate, with straight ventral margin; median line
+  biarcuate; no central area. Striæ on the dorsal side not interrupted, 9 in 10 µ. Ventral side
+  striate toward the ends.</p>
+
+  <p>Differs from A. robusta chiefly in size and coarseness of puncta. Extremely variable in
+  size.</p>
+
+  <p>Common along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Figs. 5, 6, and 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA OVALIS (BRÉB.)
+  KUETZ.</span></p>
+
+  <p>Frustule elliptical, truncate; valve lunate; median line biarcuate; striæ on dorsal side 10-16
+  in 10 µ.</p>
+
+  <p><i>Var. libyca (Ehr.) Cl.</i>&mdash;Central area distinct on the dorsal side.</p>
+
+  <p><i>Var. pediculus (Kuetz.) Cl.</i>&mdash;Central area and nodule quite distinct. Striæ finer
+  than in var. libyca.</p>
+
+  <p>Common in ponds. Quite variable.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA GIGANTEA VAR. FUSCA A.
+  S.</span></p>
+
+  <p>Frustule elliptical; valve lunate, with straight ventral margin. Axial area absent on the
+  dorsal side; dorsal striæ, 10 in 10 µ, punctate. Ventral part hyaline except at the ends, which
+  are obliquely striated, with short, punctate lines. L. 70-120 µ.</p>
+
+  <p>Absecon, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate38"><b>38</b></a>, Fig. 1.</p>
+
+  <p class="ac"><span class="sc">Diplamphora</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA CRASSA GREG.</span></p>
+
+  <p>Valve linear-elliptical, with obtuse, incurved ends. Median line biarcuate. Axial and central
+  areas indistinct on the dorsal side; striæ coarsely punctate, interrupted by a longitudinal line
+  on the dorsal side.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 3.</p>
+
+  <div><span class="pagenum" id="page66">{66}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA AREOLATA GRUN.</span></p>
+
+  <p>Valve with straight ventral margin; median line straight, approximate to the ventral margin;
+  axial area indistinct; several longitudinal lines crossed by apparent costæ which alternate with
+  rows of fine puncta.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 11.</p>
+
+  <p class="ac"><span class="sc">Halamphora</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA COFFÆIFORMIS (AG.)
+  KUETZ.</span></p>
+
+  <p>Frustule lanceolate, truncate; zone with numerous divisions. Valve arcuate on the dorsal and
+  nearly straight on the ventral side; ends protracted or slightly capitate.</p>
+
+  <p><i>A. aponina</i> Kuetz.</p>
+
+  <p><i>A. salina</i> Wm. Sm.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Figs. 8 and 18.</p>
+
+  <p class="ac"><span class="sc">Oxyamphora</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA LINEOLATA EHR.</span></p>
+
+  <p>Frustule membranaceous, elliptical, truncate, with broad ends. Zone with numerous divisions.
+  Dorsal part striated transversely; ventral side with longitudinal lines.</p>
+
+  <p><i>A. plicata</i> Greg.</p>
+
+  <p><i>A. hyalina</i> H. L. Smith, Type No. 64.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Figs. 9 and 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA OSTREARIA
+  BRÉB.</span></p>
+
+  <p>Frustule oblong, with rounded angles. Zone with five or more divisions transversely striated.
+  Central area narrow, biarcuate; central nodule dilated to a stauros. Valve narrow, with arcuate
+  dorsal and straight ventral margin, acute at the ends. Striæ transverse, finely punctate.</p>
+
+  <p><i>A. vitræa</i> Cl.; <i>A. porcellus</i> Kitton; <i>A. quadrata</i> Bréb.; <i>A. elegans</i>
+  Greg. Appearance varies according to the position of the valve.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Figs. 12 and 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA LÆVIS GREG.</span></p>
+
+  <p>Frustule oblong, hyaline and membranaceous. Valve linear or slightly arcuate, with ventral
+  margin tumid in the middle; ends obtuse; central nodule dilated to a stauros; median line very
+  narrow, biarcuate, coinciding with the dorsal margin at the ends; striæ transverse, punctate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA ACUTA GREG.</span></p>
+
+  <p>Valve lunate, with acute ends; ventral margin straight; ventral side very narrow. Central
+  nodule dilated to a stauros; striæ transverse, punctate.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 20.</p>
+
+  <div><span class="pagenum" id="page67">{67}</span></div>
+
+  <p class="ac"><span class="sc">Amblyamphora</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA OBTUSA GREG.</span></p>
+
+  <p>Frustule rectangular. Valve linear, obliquely rounded at the ends, with arcuate dorsal, and
+  straight ventral, margin; median line biarcuate; striæ, 18-20 in 10 µ.</p>
+
+  <p>Along the coast. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 4.</p>
+
+  <p class="ac"><span class="sc">Psammamphora</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA ARENARIA DONK.</span></p>
+
+  <p>Frustule hyaline, rectangular, slightly tumid in the middle, with rounded angles. Valve linear
+  with broad ventral side and straight or sinuate ventral margin. Striæ, 24-27 in 10 µ (Cleve).</p>
+
+  <p>Common along the coast.</p>
+
+  <p>Pl. <a href="#plate15"><b>15</b></a>, Fig. 17.</p>
+
+  <p class="sp3">The distinction between A. obtusa and A. arenaria is not always evident if the
+  valves alone are seen. The former has a complex zone, the latter a simple zone, and the valve has
+  finer striæ. Cleve's descriptions and references in regard to these two forms do not agree with
+  the descriptions and figures of H. L. Smith, or with the figures of Schmidt. The valves of most
+  Amphoræ are capable of assuming various outlines according to their position.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA OCELLATA VAR. CINGULATA
+  CLEVE</span></p>
+
+  <p>Frustule rectangular. Valve linear, with dorsal margin arcuate and the ventral margin straight.
+  Central nodule with a stauros on the dorsal side.</p>
+
+  <p>Squan River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Figs. 14 and 15.</p>
+
+  <p class="ac"><span class="sc">Cymbamphora</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHORA ANGUSTA VAR. EULENSTEINII
+  GRUN.</span></p>
+
+  <p>Valve lanceolate, acute at the ends. Median line straight, approximate to the margin. Axial
+  area widened on the dorsal side, indistinct on the ventral; striæ punctate.</p>
+
+  <p><i>A. eulensteinii</i> A. S.</p>
+
+  <p>Common along the coast.</p>
+
+  <p>Pl. <a href="#plate15"><b>15</b></a>, Fig. 16.</p>
+
+  <p>On Pl. <a href="#plate40"><b>40</b></a>, Figs. 21, 22, and 23, I have attempted, imitating H.
+  L. Smith's figures (Lens, l.c.), to illustrate the difference in the transverse sections of
+  Navicula, Cymbella and Amphora.</p>
+
+  <p>Fig. 21 represents the transverse section of a convex Navicula, in which the valves ecg and fdh
+  are parallel, and the median nodules c and d are central.</p>
+
+  <p>Fig. 22 is a transverse section of Cymbella in which the valves are nearly parallel and the
+  median nodules are excentric. The girdles on one side, ea and af, are narrower than gb and bh on
+  the other side.</p>
+
+  <p class="sp3">Fig. 23 is a transverse section of an Amphora in which the valves appear in zone
+  view with the median nodules of both valves on the same side. The girdles on the ventral side, ea
+  and af, are narrower than gb and bh on the dorsal side. The girdles on the dorsal side are seldom
+  as broad as gb and bh, the valve extending over a great part of the dorsal side to g&prime; and
+  h&prime;.</p>
+
+  <div><span class="pagenum" id="page68">{68}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Amphiprora</span> <span
+  class="smaller">EHR.</span> (1843)</h4>
+
+  <p class="ac">(amphi, on both ends, and prora, a prow)</p>
+
+  <p>Frustule twisted in the longitudinal axis, constricted in the middle; zone complex, with
+  numerous divisions crossed by fine striæ. Valve lanceolate, acute. The raphe confined within a
+  sigmoid keel or extension of the valve; the central and terminal nodules indistinct. Striæ
+  transverse, punctate, with coarser striæ at the junction of the keel and lower part of the
+  valve.</p>
+
+  <p class="sp3">Chromatophores single, with indented border except in A. pulchra, in which there
+  are two chromatophores with entire borders.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHIPRORA ALATA
+  KUETZ.</span></p>
+
+  <p>Frustule with a row of puncta at the junction line. Valve linear, acute at the ends. Median
+  line sigmoid. Striæ lineate on the lower part of the valve, punctate on the keel.</p>
+
+  <p>Along the coast. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate14"><b>14</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHIPRORA PULCHRA
+  BAIL.</span></p>
+
+  <p>Frustule with sigmoid connective zone. Valve very convex, with sinuate keel and junction lines
+  evident. In zone view and in valve view, one half of the frustule, owing to the elevation of the
+  keel, is wider than the other half. Striæ punctate, coarser on the keel.</p>
+
+  <p>Not uncommon along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate14"><b>14</b></a>, Figs. 1 and 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHIPRORA CONSPICUA
+  GREV.</span></p>
+
+  <p>Valve linear or elliptical, with acute ends. Median line sigmoid, but the junction lines not
+  evident. Striæ lineate, with coarser lines near the middle.</p>
+
+  <p>Not common. Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate14"><b>14</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHIPRORA ORNATA
+  BAIL.</span></p>
+
+  <p>Frustule membranaceous, constricted in the middle, with well-marked folds extending from the
+  junction line in both directions. Valve lanceolate, constricted in the middle and with protracted
+  ends. Keel undulate on the edge.</p>
+
+  <p>A beautiful, transparent and delicate form, the only fresh-water species in our locality.</p>
+
+  <p>Delaware Water Gap, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate14"><b>14</b></a>, Figs. 6 and 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHIPRORA PALUDOSA WM.
+  SM.</span></p>
+
+  <p>Frustule membranaceous, constricted, with truncate ends. Valve linear, with acute ends. Striæ
+  scarcely visible.</p>
+
+  <p>Cape May (Cleve).</p>
+
+  <p class="sp3">Pl. <a href="#plate14"><b>14</b></a>, Fig. 5.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Tropidoneis Cleve</span> (1891)</h4>
+
+  <p class="ac">(tropis, a keel)</p>
+
+  <p class="sp3">Frustule oblong, constricted in the middle; keel not sigmoid. Axial area not
+  evident. Striæ very fine, punctate, in longitudinal lines.</p>
+
+  <div><span class="pagenum" id="page69">{69}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TROPIDONEIS LEPIDOPTERA (GREG.)
+  CLEVE</span></p>
+
+  <p>Valve with straight, median excentric line. Keel unilateral, projecting above the median line
+  in zone view; central area small. Transverse striæ finely punctate. As usually seen, the valve is
+  inclined. According to Karsten there are two chromatophores on the connective zone, each divided
+  into four parts, each of which contains a large oval pyrenoid.</p>
+
+  <p><i>Amphiprora lepidoptera</i> Greg.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate14"><b>14</b></a>, Figs. 8 and 9.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Auricula</span> <span
+  class="smaller">CASTRACANE</span> (1873)</h4>
+
+  <p class="ac">(auricula, the ear, the shape of the valve)</p>
+
+  <p class="sp3">Frustule globose. Valve reniform or cymbiform, elevated into a keel which is not
+  sigmoid. Median line biarcuate. Differs from Amphiprora in not having a sigmoid keel.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AURICULA MUCRONATA (H. L. SMITH)
+  PERAGALLO</span></p>
+
+  <p>In zone view, the median line deeply bisects the longitudinal axis, ending in a mucronate
+  central nodule. Connective zone complex. Valve very complex, with ventral margin nearly straight
+  and raphe excentric. Central nodule near the margin, terminal nodules small. Striæ, 35-40 in 10 µ
+  (Cleve). Chromatophore single, on the ventral part.</p>
+
+  <p><i>Amphora mucronata</i> H. L. Smith.</p>
+
+  <p><i>Amphora (?) insecta</i> Grun.</p>
+
+  <p><i>Auricula insecta</i> (Grun.) Cleve.</p>
+
+  <p>"A rare and very curious pelagic species" (Peragallo, Diat. Villefranche).</p>
+
+  <p>Prof. H. L. Smith included this form in his first century of "Species Typicæ Diatomacearum,"
+  which was issued prior to 1876, the date of publication, in Schmidt's Atlas, of Amphora insecta
+  Grun.</p>
+
+  <p>Atlantic City, N. J. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate15"><b>15</b></a>, Fig. 2.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Scoliotropis</span> <span
+  class="smaller">CLEVE</span> (1894)</h4>
+
+  <p class="ac">(scolios, twisted, and tropis, a keel)</p>
+
+  <p class="sp3">Frustule linear, oblong. Median line sigmoid near the ends. Valve with transverse
+  costæ alternating with two intermediate rows of puncta in oblique lines.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SCOLIOTROPIS LATESTRIATA VAR.
+  AMPHORA CLEVE</span></p>
+
+  <p>Valve asymmetrical, with the median line curved. Frustule sub-acute at the ends. Median lines
+  not on the same side of each valve of the frustule.</p>
+
+  <p>Abundant at Cape May, N. J. Not common elsewhere.</p>
+
+  <p class="sp3">Pl. <a href="#plate14"><b>14</b></a>, Figs. 10 and 11.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Gomphoneis</span> <span
+  class="smaller">CLEVE</span> (1894)</h4>
+
+  <p class="ac">(gomphos, a peg, and neis (naus))</p>
+
+  <p>Valve elongated, asymmetrical to the transverse axis; axial area narrow; central area rounded,
+  stigmatic; striæ radiating, costæ alternating with double rows of fine puncta. An indistinct,
+  longitudinal line near the border.</p>
+
+  <p class="sp3">Chromatophores and conjugation have not been determined.</p>
+
+  <div><span class="pagenum" id="page70">{70}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEIS HERCULANEUM (EHR.)
+  CL.</span></p>
+
+  <p>Valve clavate, with rounded apex; costæ, 13 in 10 µ, alternating with double rows of fine
+  puncta, 22 in 10 µ, in oblique rows; axial area narrow, central area rounded, with one stigma.</p>
+
+  <p><i>Gomphonema capitatum</i> Ehr var. <i>herculaneum</i> Ehr., H. L. S., Type Slide No. 177.</p>
+
+  <p>Common in the blue clay.</p>
+
+  <p>Pl. <a href="#plate19"><b>19</b></a>, Fig. 2.</p>
+
+  <p class="sp3">Pl. <a href="#plate38"><b>38</b></a>, Fig. 15, zone view of young frustule.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEIS MAMILLA (EHR.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, with rounded apex and base; striæ costate, 10 in 10 µ, alternating with
+  double rows of fine puncta; axial area linear, sometimes oblique, central area small, with one or
+  more stigmas.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Pl. <a href="#plate19"><b>19</b></a>, Fig. 1.</p>
+
+  <p>In one frustule I noticed one valve with one stigma and the other with four stigmas.</p>
+
+  <p class="sp3">The difference between G. mamilla and G. elegans is not very great. In the latter
+  the central area is larger and the longitudinal lines not so near to the margin. The stigmas form
+  a circlet. There appears to be a coincidence in the relation of Gomphoneis to Gomphonema, and that
+  of the true Achnanthes to the group described by Cleve under Achnanthidium. In Gomphoneis and
+  Achnanthes the striation is both costate and punctate while in Gomphonema and Achnanthidium the
+  striation is punctate only.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Gomphonema</span> <span
+  class="smaller">AG.</span> (1824)</h4>
+
+  <p class="ac">(gomphos, a peg, and nema, a filament)</p>
+
+  <p>Valve elongated, asymmetrical with respect to the transverse axis; striæ transverse, usually
+  radiate, punctate.</p>
+
+  <p>Chromatophore band single, the middle lying on one zone.</p>
+
+  <p>In conjugation, according to Thwaites and Pfitzer, from two mother cells, which do not form a
+  positive union, two auxospores are developed parallel to the original frustules. In Plate <a
+  href="#plate19"><b>19</b></a>, Fig. 19, I have drawn a representation of the auxospore formation
+  as I have frequently observed it in a gathering sent me by Mr. T. C. Palmer, containing G.
+  angustatum, a common species in this locality. The sagittal plane of the valve of the auxospore is
+  at right angles to the plane of the valve of the mother cell. Two valves of one of the mother
+  cells are seen separated, one on each side of the auxospore which is nearly twice the length of
+  the original frustules. The two valves of the other mother cell are not shown as they are not
+  usually found closely united. In the figure one valve alone of the auxospore is seen, the opposite
+  valve not being in focus. The valves of the auxospore are usually more or less arcuate, as in
+  Cymbella, to which the genus is closely allied.</p>
+
+  <p class="sp3">Grunow divides Gomphonema into two groups, Asymmetricæ and Symmetricæ, according to
+  the presence or absence of stigmas. Cleve suggests Stigmaticæ and Astigmaticæ as more suitable in
+  order to agree with the Cymbellæ. The Stigmaticæ are found chiefly in fresh water, sometimes in
+  brackish. All of the marine forms belong to the Astigmaticæ, which, however, include some common
+  fresh-water forms. Many species of Gomphonema are stipitate, some occur in gelatinous masses, and
+  others are free.</p>
+
+  <div><span class="pagenum" id="page71">{71}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA MONTANUM
+  SCHUM.</span></p>
+
+  <p>Valve slightly biconstricted, with obtuse apex and basis, somewhat cuneate; axial area linear,
+  widened in the middle unilaterally; stigma, one; striæ about 11 in 10 µ, more distant in the
+  middle, punctate.</p>
+
+  <p><i>Gomphonema subclavatum</i> var. <i>montana</i> (Schum.) Cl.</p>
+
+  <p>Pavonia, N. J., artesian well. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA GEMINATUM
+  LYNG.</span></p>
+
+  <p>Valve biconstricted, with large, rounded, sub-truncate apex and broad, sub-truncate basis;
+  striæ, 9 in 10 µ, radiate in the middle, alternately longer and shorter, transverse at the basis
+  and near the apex where they again radiate, coarsely punctate, puncta, 12 in 10 µ. Axial area
+  linear; central area rounded, with several large stigmas in a longitudinal row; terminal fissures
+  hook-shaped.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA LANCEOLATUM VAR.
+  INSIGNIS (GREG.) CL.</span></p>
+
+  <p>Valve lanceolate; axial area narrow; central area unilateral with one stigma; striæ with coarse
+  and distant puncta.</p>
+
+  <p>Common and variable.</p>
+
+  <p><i>Gomphonema insigne</i> Greg.</p>
+
+  <p>Pl. <a href="#plate19"><b>19</b></a>, Figs. 6 and 12.</p>
+
+  <p class="sp3">Fig. 12 shows a unilateral central area. Fig. 6 is more clavate in outline with
+  small central area. In both forms the coarse puncta are in distinct longitudinal lines in the
+  middle.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA ACUMINATUM VAR. TURRIS
+  (EHR.) CL.?</span></p>
+
+  <p>Valve clavate, with cuneate, acute apex; axial area distinct; central area unilateral with one
+  stigma.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA ACUMINATUM VAR. TURRIS
+  (EHR.) CL.</span></p>
+
+  <p>Valve clavate, with cuneate apiculate apex and narrow basis; axial area narrow, with a
+  unilateral central space; stigma opposite the short striæ; striæ more radiate in the upper part,
+  distant in the middle.</p>
+
+  <p>Smith's Island, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA ACUMINATUM VAR.
+  CORONATA (EHR.) CL.</span></p>
+
+  <p>Valve twice constricted, with broad, cuneate apex; striæ radiate in the middle, convergent near
+  the apex and radiate at the apex. Variable in size and outline.</p>
+
+  <p>Blue clay. Fresh water. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA ACUMINATUM VAR.
+  TRIGONOCEPHALA (EHR.) CL.</span></p>
+
+  <p>Valve broad, with cuneate apex; axial area narrow; central area unilateral with one stigma.</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 20.</p>
+
+  <div><span class="pagenum" id="page72">{72}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA CONSTRICTUM
+  EHR.</span></p>
+
+  <p>Valve clavate, constricted beneath the abruptly rounded apex, gibbous in the middle, striæ
+  alternately longer and shorter; axial area narrow, central area unilateral, with one stigma.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA SPHÆROPHORUM
+  EHR.</span></p>
+
+  <p>Valve clavate, with capitate or rostrate-capitate apex and narrow basis; axial area very
+  narrow; central area small, unilateral, with one stigma.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Figs. 9 and 10. Fig. 10 appears to be a
+  transitional form having a more distinct axial area and rostrate apex.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA AUGUR EHR.</span></p>
+
+  <p>Valve broadly clavate, truncate and apiculate at the apex; basis sub-acute; axial area
+  distinct; central area small, unilateral with one stigma; striæ with distant puncta.</p>
+
+  <p>Blue clay. Willistown, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA INTRICATUM
+  KUETZ.</span></p>
+
+  <p>Valve narrow, lanceolate, slightly gibbous in the middle; axial area distinct; central area
+  transverse with one stigma; striæ parallel. Quite variable.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA ANGUSTATUM
+  KUETZ.</span></p>
+
+  <p>Valve lanceolate, with sub-rostrate apex and basis; axial area indistinct; central area
+  unilateral, with one small stigma; striæ slightly radiate, indistinctly punctate.</p>
+
+  <p>Very common in fresh water.</p>
+
+  <p>Pl. <a href="#plate19"><b>19</b></a>, Figs. 18 and 19.</p>
+
+  <p class="sp3">Fig. 19, as stated above, represents the formation of an auxospore.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA ÆQUALE
+  GREG.</span></p>
+
+  <p>Valve linear-lanceolate, nearly symmetrical, with capitate apex and basis; axial area narrow;
+  central area unilateral, with one stigma; striæ radiate in the middle, slightly convergent at the
+  ends.</p>
+
+  <p><i>Gomphonema intricatum var. æquale</i> (Greg.) Cl.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA SARCOPHAGUS
+  GREG.</span></p>
+
+  <p>Valve linear, irregular in outline, with rounded apex and basis; axial area distinct; central
+  area small, unilateral, with one stigma; striæ irregular with coarse, distinct puncta.</p>
+
+  <p>Occasional in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA CAPITATUM
+  EHR.</span></p>
+
+  <p>Valve clavate, broad at the sub-truncate apex and slightly constricted, or with parallel
+  margins; axial area linear, central area stellate, with one stigma; striæ in the middle
+  alternately longer and shorter.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 22.</p>
+
+  <div><span class="pagenum" id="page73">{73}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA PARVULUM VAR. MICROPUS
+  (KUETZ.) CL.</span></p>
+
+  <p>Valve clavate, with rounded apex and basis; axial area indistinct; central area unilateral,
+  with a small stigma; striæ distant in the middle.</p>
+
+  <p>Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 17.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA VENTRICOSUM
+  GREG.</span></p>
+
+  <p>Valve clavate, with broad apex and produced, rounded basis; axial area narrow, widened in the
+  middle; stigma one; striæ distant in the middle, finely punctate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA OLIVACEUM
+  LYNG.</span></p>
+
+  <p>Valve clavate, with broad apex and narrow basis; axial area very narrow; central area
+  irregular, without stigma; striæ radiate, finely punctate.</p>
+
+  <p>Very common.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GOMPHONEMA BRASILIENSE VAR.
+  DEMERARÆ GRUN.?</span></p>
+
+  <p>Valve lanceolate, with sub-cuneate apex and narrowed basis; axial area lanceolate, broad; no
+  stigma; median fissures remote; striæ parallel, 12 in 10 µ, punctate, the puncta obsolescent,
+  small or interrupted.</p>
+
+  <p>Willistown, Pa. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate19"><b>19</b></a>, Fig. 24.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Pleurosigma</span> <span
+  class="smaller">WM. SM.</span> (1852)</h4>
+
+  <p class="ac">(pleura, a side, and sigma, the letter s)</p>
+
+  <p>Valve lanceolate, sigmoid; axial area very narrow, central area small; striæ punctate, in
+  transverse and oblique lines.</p>
+
+  <p>Cleve divides the forms usually known as Pleurosigma into two genera, Pleurosigma and
+  Gyrosigma. Pleurosigma includes all forms having oblique rows of puncta, while Gyrosigma includes
+  all having longitudinal rows. Both have transverse striæ. The former consists entirely of marine
+  species, while in the latter the species are found in fresh, brackish and salt water.</p>
+
+  <p>The endochrome in Pleurosigma, according to Mueller, consists of two bands which differ in the
+  median part of each valve. Mereschkowsky says that the endochrome is so divided as to form four
+  bands, two on each valve, that their position is different in different species, and that they are
+  not the same on valves of the same frustule.</p>
+
+  <p class="sp3">Cleve prefers to classify the species of Pleurosigma and Gyrosigma in accordance
+  with the outline of the valve and the flexure of the median line. I shall, however, retain the
+  method used by Peragallo and Grunow and arrange the forms according to the striation.</p>
+
+  <p class="ac">(1) <span class="sc">Oblique Striæ about 90 Degrees, More Distinct Than the
+  Transverse</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA FORMOSUM WM.
+  SM.</span></p>
+
+  <p>Valve elongated, slender, gently sigmoid, acute at the ends; oblique striæ crossing each other
+  at about 90 degrees; 10-16 in 10 µ; transverse striæ, 14-20 in 10 µ (Cleve).</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 5.</p>
+
+  <div><span class="pagenum" id="page74">{74}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA OBSCURUM WM.
+  SM.</span></p>
+
+  <p>Valve linear, not sigmoid, or scarcely so; ends obtuse, subconical; raphe sigmoid, near the
+  margin at the extremities; transverse and oblique striæ equidistant, 28 in 10 µ (Wm. Sm.).</p>
+
+  <p>Abundant at Greenwich Point, Philadelphia.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 4.</p>
+
+  <p class="ac">(2) <span class="sc">Oblique Striæ Closer At The Ends</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA NAVICULACEUM
+  BRÉB.</span></p>
+
+  <p>Valve lanceolate, slightly sigmoid at the extremities; raphe strongly sigmoid near the margin
+  at the ends; central nodule large, rounded; oblique striæ, 13-14 in the middle, closer at the
+  ends; transverse striæ, 18-20 in 10 µ (Peragallo).</p>
+
+  <p>Long Island Sound.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA VIRGINIACUM H. L.
+  SMITH</span></p>
+
+  <p>Valve slightly sigmoid, with acute ends; raphe more sigmoid than the valve, excentric near the
+  ends; oblique striæ in different directions at the centre, 13 in 10 µ, closer and less distinct at
+  the ends; central nodule small but prominent because of its thickness, producing by diffraction an
+  apparently wide area (somewhat exaggerated in the figure). L. 95 µ, usually larger.</p>
+
+  <p><i>P. affine</i> var. <i>fossilis</i> Grun. (Peragallo).</p>
+
+  <p><i>P. normanii</i> var. <i>fossilis</i> Grun. (Cleve).</p>
+
+  <p>Common in the blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 8.</p>
+
+  <p class="ac">(3) <span class="sc">Oblique Striæ 60 Degrees</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA ANGULATUM (QUEKETT)
+  CL.</span></p>
+
+  <p>Valve rhomboidal, with sub-rostrate or produced ends; central nodule rhomboidal; raphe central;
+  transverse and oblique striæ at an angle of 60 degrees, equidistant, 18-22 in 10 µ.</p>
+
+  <p><i>Navicula angulata</i> Quekett.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA STRIGOSUM WM.
+  SM.</span></p>
+
+  <p>Valve lanceolate, with sub-acute, somewhat revolute, apices; oblique striæ at an angle of about
+  60 degrees, otherwise as in angulatum.</p>
+
+  <p>Along the coast. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA ÆSTUARII
+  BRÉB.</span></p>
+
+  <p>Valve lanceolate, with produced apices; raphe less sigmoid than the valve and excentric;
+  oblique striæ, 19-21 in 10 µ, at an angle of about 60 degrees.</p>
+
+  <p>Along the coast. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 7.</p>
+
+  <div><span class="pagenum" id="page75">{75}</span></div>
+
+  <p class="ac">(4) <span class="sc">Oblique Striæ 60 Degrees, The Transverse More
+  Distant</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PLEUROSIGMA RIGIDUM WM.
+  SM.</span></p>
+
+  <p>Valve nearly straight or slightly sigmoid, with obtuse ends; raphe central, excentric near the
+  ends; oblique striæ, 17-21, transverse, 16-19 in 10 µ. (Peragallo).</p>
+
+  <p>New Rochelle, N. Y.</p>
+
+  <p class="sp3">Pl. <a href="#plate22"><b>22</b></a>, Fig. 2 (very near the var. gigantea
+  Grun.)</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Gyrosigma Hassall</span> (1845)</h4>
+
+  <p class="ac">(gyros, curved, and sigma)</p>
+
+  <p>Valve lanceolate, sigmoid; axial area very narrow, central area small; striæ punctate, in
+  transverse and longitudinal rows.</p>
+
+  <p>Chromatophores two, in long and narrow bands, perforated, differing from those of Pleurosigma.
+  The elæoplasts are also arranged differently in the two genera. (Mereschkowsky, Études sur
+  l'Endochrome des Diatomées, Imperial Academy of Petrograd, 1901, Vol. 11, No. 6, p. 18 et
+  seq.)</p>
+
+  <p class="sp3">The arrangement is according to Peragallo.</p>
+
+  <p class="ac">(1) <span class="sc">Longitudinal Striæ More Distant Than The Transverse</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA HIPPOCAMPUS
+  (EHR.)</span></p>
+
+  <p>Valve lanceolate, sigmoid, with obtuse ends; raphe nearly central; transverse striæ 15-17,
+  longitudinal, 10-12 in 10 µ.</p>
+
+  <p><i>Navicula hippocampus</i> Ehr.</p>
+
+  <p><i>Pleurosigma hippocampus</i> (Ehr.) Wm. Sm.</p>
+
+  <p><i>Gyrosigma attenuatum</i> (Kuetz.) Cl.</p>
+
+  <p>Long Island Sound.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 3.</p>
+
+  <p class="ac">(2) <span class="sc">Longitudinal and Transverse Striæ Nearly Equal</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA BALTICUM (EHR.)
+  CL.</span></p>
+
+  <p>Valve with margins parallel nearly to the extremities, which are suddenly unilaterally
+  sub-conical and obtuse; raphe sigmoid; transverse and longitudinal striæ nearly equally distant,
+  15 in 10 µ (Per.). L. 200-360 µ.</p>
+
+  <p><i>Navicula baltica</i> Ehr.</p>
+
+  <p><i>Pleurosigma balticum</i> (Ehr.) Wm. Sm.</p>
+
+  <p>Common along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA PARKERI VAR.
+  STAURONEIOIDES GRUN.</span></p>
+
+  <p>Valve lanceolate, slightly sigmoid, ends produced into beaks with sub-acute apices; raphe
+  straight in the middle part; central nodule elliptical; transverse striæ, 21, and longitudinal, 24
+  in 10 µ (Per.).</p>
+
+  <p>An apparent stauros, variable in width, extends to the margin and, in consequence, the median
+  transverse striæ are more evident. L. 75 µ.</p>
+
+  <p>Schuylkill River. Rather rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 7.</p>
+
+  <div><span class="pagenum" id="page76">{76}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA SIMILE
+  (GRUN.)</span></p>
+
+  <p>Valve slightly sigmoid, broad, with obtuse ends; raphe sigmoid, nearly central; transverse
+  striæ, 15, longitudinal, 16-17 in 10 µ (Per.).</p>
+
+  <p><i>Pleurosigma simile</i> Grun.</p>
+
+  <p><i>Gyrosigma balticum</i> var. <i>similis</i> (Grun.) Cl.</p>
+
+  <p>Shark River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 4.</p>
+
+  <p class="ac">(3) <span class="sc">Transverse Striæ More Distant</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA ACUMINATUM (KUETZ.)
+  CL.</span></p>
+
+  <p>Valve sigmoid, tapering to the sub-acute ends; raphe central; transverse and longitudinal striæ
+  nearly equally distant, 17 or 18 in 10 µ (Per.).</p>
+
+  <p><i>Frustulia acuminata</i> Kuetz.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA STRIGILIS (WM. SM.)
+  CL.</span></p>
+
+  <p>Valve sigmoid, with obtuse ends; raphe doubly sigmoid; axial area rather wide; transverse
+  striæ, 13, and longitudinal, about 16 in 10 µ.</p>
+
+  <p>Long Island Sound. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA KUETZINGII (GRUN.)
+  CL.</span></p>
+
+  <p>Valve sigmoid, lanceolate, with sub-acute ends; raphe central, the central nodule elliptical;
+  transverse striæ, 21-23, and longitudinal, 25-26 in 10 µ.</p>
+
+  <p><i>Pleurosigma spencerii</i> var. <i>acutiuscula</i> Grun.</p>
+
+  <p><i>Pleurosigma spencerii</i> var. <i>kuetzingii</i> Grun.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate38"><b>38</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA SCALPROIDES (RAB.)
+  CL.</span></p>
+
+  <p>Valve slightly sigmoid, with obtuse ends; raphe nearly straight; central nodule elliptical;
+  transverse striæ, 22, slightly radiate and more distant in the middle; longitudinal striæ, 29 in
+  10 µ. L. 60 µ.</p>
+
+  <p>Common in streams.</p>
+
+  <p>Pl. <a href="#plate38"><b>38</b></a>, Fig. 9.</p>
+
+  <p class="sp3">In Pl. <a href="#plate23"><b>23</b></a>, Fig. 6 represents a form more sigmoid.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA SPENCERII VAR. NODIFERA
+  GRUN.</span></p>
+
+  <p>Valve sigmoid, with obtuse ends; raphe central; central nodule obliquely elongated; transverse
+  striæ, 17-18 in 10 µ, curved in the middle of the valve, longitudinal striæ, 22 in 10 µ. L. 150
+  µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA PROLONGATUM (WM. SM.)
+  CL.</span></p>
+
+  <p>Valve narrow, lanceolate, produced into beaks, curved in a contrary direction; raphe central;
+  transverse striæ, 20-21 in 10 µ, longitudinal closer. L. 140 µ.</p>
+
+  <p>Along the coast, northward.</p>
+
+  <p>Pl. <a href="#plate38"><b>38</b></a>, Fig. 13.</p>
+
+  <p class="sp3">I have not seen any specimens south of New England, but they will probably
+  occur.</p>
+
+  <div><span class="pagenum" id="page77">{77}</span></div>
+
+  <p class="ac">(4) <span class="sc">Striæ Alike, Extremities Produced</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GYROSIGMA FASCIOLA (EHR.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, attenuated into curved beaks turned in opposite directions; raphe central,
+  straight, except at the beaks; transverse striæ, 22, longitudinal, 24 in 10 µ (Per.).</p>
+
+  <p>New York Bay.</p>
+
+  <p class="sp3">Pl. <a href="#plate23"><b>23</b></a>, Fig. 9.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Frustulia</span> <span
+  class="smaller">AG.</span> (1824); em. <span class="smaller">GRUN.</span> (1865)</h4>
+
+  <p class="ac">(frustulum, a small piece)</p>
+
+  <p>Valves naviculoid, similar, usually free but sometimes enclosed in gelatinous tubes or embedded
+  in mucus. Median line between two thickened ribs. Central and terminal nodules frequently
+  elongated. Surface of valve with fine puncta in longitudinal and transverse lines appearing
+  hyaline under medium powers.</p>
+
+  <p>Chromatophores, two, extending along the girdle. They differ from those of Navicula in being
+  separated from the wall in the middle by a hemispherical mass of protoplasm. According to Pfitzer,
+  each chromatophore is divided in the middle, allowing a connection between the hemispherical mass
+  and the central plasma mass. Schmitz states that the chromatophore is thickened in the middle and
+  contains a pyrenoid.</p>
+
+  <p class="sp3">In conjugation, two frustules form two cylindrical bodies which later become
+  conical and from which are formed the sporangial valves twice the usual size.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRUSTULIA LEWISIANA (GREV.) DE
+  TONI</span></p>
+
+  <p>Valve elliptical or linear, with rounded ends; terminal nodules elongated, at a distance from
+  the ends; striæ, 24 in 10 µ.</p>
+
+  <p>Port Penn, Delaware River. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRUSTULIA RHOMBOIDES (EHR.) DE
+  TONI</span></p>
+
+  <p>Valve lanceolate or rhombic-lanceolate, rounded at the ends; central and terminal nodules
+  short; striæ, 20 in 10 µ, sometimes coarser.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRUSTULIA RHOMBOIDES VAR.
+  AMPHIPLEUROIDES GRUN.</span></p>
+
+  <p>Valve rhombic-lanceolate; central and terminal nodules elongated; median line somewhat
+  excentric.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRUSTULIA RHOMBOIDES VAR.
+  SAXONICA (RAB.) DE TONI</span></p>
+
+  <p>Valve smaller than in rhomboides, with somewhat produced ends, closer median ribs and rounded
+  central nodule.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRUSTULIA VULGARIS (THWAITES) DE
+  TONI</span></p>
+
+  <p>Valve elliptical-lanceolate, with rounded or sometimes sub-rostrate ends; central and terminal
+  nodules slightly elongated; striæ delicate, closer at the ends. Frustules at first in gelatinous
+  tubes.</p>
+
+  <p><i>Colletonema vulgaris</i> Thwaites.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 4.</p>
+
+  <div><span class="pagenum" id="page78">{78}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">FRUSTULIA INTERPOSITA (LEWIS) DE
+  TONI</span></p>
+
+  <p>Valve linear-elliptical, rounded at the ends; terminal nodules short.</p>
+
+  <p><i>Navicula interposita</i> Lewis.</p>
+
+  <p>Along the coast. Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 5.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Amphipleura</span> <span
+  class="smaller">KUETZ.</span> (1844)</h4>
+
+  <p class="ac">(amphi, on both sides, pleura, a side)</p>
+
+  <p>Frustules free, in gelatinous masses or in tubes. Valve linear-lanceolate; central nodule
+  narrow, extending half the length of the valve or more, then forking toward the ends. Terminal
+  nodules prolonged, as in Frustulia, into a "porte-crayon-shaped" figure.</p>
+
+  <p class="sp3">Chromatophores two, very short.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHIPLEURA PELLUCIDA
+  KUETZ.</span></p>
+
+  <p>Frustules free or in mucous masses. Valve fusiform; forks about one-fourth the length of the
+  valve; striæ transverse, punctate, 36-40 in 10 µ (J. J. Woodward).</p>
+
+  <p>Occasional in the Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">AMPHIPLEURA RUTILANS (TRENTEPOHL)
+  CL.</span></p>
+
+  <p>Frustules enclosed in gelatinous tubes. Valve linear-lanceolate, obtuse at the ends; forks
+  about one-third the length of the valve; striæ, 28 in 10 µ.</p>
+
+  <p><i>Conferva rutilans</i> Trentepohl.</p>
+
+  <p><i>Schizonema dillwynii</i> Wm. Sm.</p>
+
+  <p>Abundant at Belmar, N. J.</p>
+
+  <p>Pl. <a href="#plate17"><b>17</b></a>, Fig. 10.</p>
+
+  <p class="sp3">Fig. 11 represents a portion of the gelatinous tube containing frustules.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Dictyoneis</span> <span
+  class="smaller">CLEVE</span> (1890)</h4>
+
+  <p class="ac">(dictyon, a net)</p>
+
+  <p>Frustules oblong. Valve lanceolate, constricted in the middle (in our species); an outer layer
+  finely punctate and an inner layer of reticulations; the margin of the valve divided into large,
+  quadrate cells.</p>
+
+  <p>The genus Dictyoneis includes species at one time ascribed to Mastogloia and Navicula. The
+  structure, however, is not like that of either, as the loculi are attached to the valve and are
+  not separable as in Mastogloia, and the cell-wall is not like that of any Navicula.</p>
+
+  <p class="sp3">Cleve remarks that Dictyoneis is found in warm waters. Lewis found one specimen at
+  Black Rock Harbor, L. I., and one in the Delaware River blue clay. The specimens here described I
+  found living on the New Jersey coast.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DICTYONEIS MARGINATA VAR. TYPICA
+  CLEVE</span></p>
+
+  <p>Valve panduriform, with cuneate lobes; axial area narrow, linear, scarcely, or not at all,
+  widened in the middle; terminal fissures in contrary directions; outer stratum finely punctate,
+  about 25 in 10 µ, in parallel striæ; inner stratum coarsely reticulated. Four and one-fourth times
+  longer than broad; marginal cells, 5 in 10 µ, smaller or obsolescent in the middle of the valve;
+  cells of the valve in irregular transverse rows, 10-12 in 10 µ. L. 93 µ.</p>
+
+  <p><i>Navicula marginata</i> Lewis.</p>
+
+  <p>Absecon, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 3.</p>
+
+  <div><span class="pagenum" id="page79">{79}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DICTYONEIS MARGINATA VAR.
+  COMMUTATA CLEVE</span></p>
+
+  <p>Valve four and one-half times longer than broad; cells of the valve in irregular, transverse
+  rows about 11 in 10 µ; marginal cells nearly equal, 6 in 10 µ. L. 125 µ.</p>
+
+  <p>Absecon, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DICTYONEIS MARGINATA VAR. MAXIMA
+  N. VAR.</span></p>
+
+  <p>Valve with cuneate segments; marginal cells, 4 in 10 µ; cells of the valve, 5 in 10 µ,
+  obsolescent in the middle and smaller; transverse striæ, 25 in 10 µ.</p>
+
+  <p>Atlantic Coast. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 1 (from a specimen found at Colon).</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Trachyneis</span> <span
+  class="smaller">CLEVE</span> (1894)</h4>
+
+  <p class="ac">(trachys, rough, and neis (naus), named from the chief species)</p>
+
+  <p>Valve more or less linear or linear-lanceolate. It appears to be composed of three strata, one
+  an interior, coarsely dotted, an exterior of fine puncta in longitudinal striæ, scarcely visible,
+  and a median of transverse anastomosing costæ forming irregular alveoli.</p>
+
+  <p class="sp3">Chromatophores, two or four bands on the zone (Mereschkowsky).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">TRACHYNEIS ASPERA VAR. INTERMEDIA
+  GRUN.</span></p>
+
+  <p>Valve linear-elliptic; axial area a stauros widened outward and unilateral. Striæ of the median
+  layer of radiating rows of oblong alveoli.</p>
+
+  <p>Along the coast. Not common.</p>
+
+  <p>Pl. <a href="#plate17"><b>17</b></a>, Fig. 15.</p>
+
+  <p class="sp3">The type form and its numerous varieties are quite ubiquitous. Very large specimens
+  occur in the Antarctic regions, especially in material from Ross Island, S. Victoria Land
+  (Shackleton Ant. Exp.).</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Brébissonia</span> <span
+  class="smaller">GRUN.</span> (1860)</h4>
+
+  <p class="ac">(named after Alphonse de Brébisson, the distinguished French naturalist)</p>
+
+  <p>Frustules stipitate; valve lanceolate; striæ transverse in the middle, radiate at the ends.
+  Median area narrow, central nodule elongated, terminal fissures at a distance from the ends. Valve
+  with an outer finely punctate stratum.</p>
+
+  <p>At one end of one valve in each frustule is found a conspicuous punctum, the plasma pore of
+  Otto Mueller, through which the frustule is connected with the gelatinous stipe, analogous to the
+  pore in Diatoma connecting the zig-zag frustules.</p>
+
+  <p class="sp3">Chromatophore single, lying on one girdle and passing over to each valve.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BRÉBISSONIA B&#x0152;CKII
+  (KUETZ.) GRUN.</span></p>
+
+  <p>Valve lanceolate, with sub-acute apices; striæ, 3-4 in 10 µ, not reaching the median line.</p>
+
+  <p>Blue clay. Very rare. Common in brackish water at Chestertown, Md. (T. C. Palmer)</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 7.</p>
+
+  <div><span class="pagenum" id="page80">{80}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">BRÉBISSONIA PALMERII, N.
+  SP.</span></p>
+
+  <p>Valve rhombic-lanceolate, with cuneate ends and produced apices. Central nodule more elongate
+  and terminal fissures further from the ends than in B. b&#x0153;ckii.</p>
+
+  <p>Pavonia, N. J. (artesian well, depth of 40 ft.). Rare.</p>
+
+  <p>Pl. <a href="#plate17"><b>17</b></a>, Fig. 8.</p>
+
+  <p>I take pleasure in naming this species after Mr. T. Chalkley Palmer, of Media, Pa., the author
+  of numerous papers on the Diatomaceæ.</p>
+
+  <p class="sp3">Lewis partly describes a similar form, which he does not name, as a species of
+  Navicula found in the blue clay at Kaighn's Point, N. J. (Lewis, "New and Intermediate Forms,"
+  etc., p. 15, Pl. 1, Fig. 8.)</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Anom&#x0153;oneis</span> <span
+  class="smaller">PFITZER</span> (1871)</h4>
+
+  <p class="ac">(anomoios, unlike, and neis (naus), a boat)</p>
+
+  <p>Valve lanceolate, axial area narrow, central area widened; transverse striæ punctate, the
+  puncta in longitudinal rows or interrupted by blank lines.</p>
+
+  <p>A single chromatophore lies along one of the girdle sides and extends over the valves, each of
+  the two parts being deeply notched or slit at the ends. According to Schmitz there are two
+  pyrenoids, but Heinzerling thinks there is but one.</p>
+
+  <p class="sp3">Cleve considers this genus not well founded, as it is based upon the cell contents
+  of but one species, the structure of the other species not being known. As the forms here
+  described are easily recognized by the interrupted puncta, the genus is, at least, convenient.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANOM&#x0152;ONEIS SPHÆROPHORA
+  (KUETZ.) CL.</span></p>
+
+  <p>Valve elliptic-lanceolate, ends rostrate-capitate. Axial area narrow, central area rounded,
+  larger on one side of the median line than the other. Striæ very slightly radiate, 16 in 10 µ,
+  punctate, the puncta interrupted by longitudinal blank lines.</p>
+
+  <p>Pfitzer states that the central plasma mass is unequal on the two sides.</p>
+
+  <p><i>Navicula sphærophora</i> Kuetz.</p>
+
+  <p>Fresh and brackish water. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate40"><b>40</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANOM&#x0152;ONEIS SERIANS (BRÉB.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, acute; axial area lanceolate; striæ, 24 in 10 µ; puncta elongate.</p>
+
+  <p>Not common in this locality, but abundant northwards; fossil in the peat deposits of New
+  England.</p>
+
+  <p>May's Landing, N. J.</p>
+
+  <p>Pl. <a href="#plate17"><b>17</b></a>, Fig. 12.</p>
+
+  <p>Forma minor&mdash;Valve rhombic-lanceolate, smaller than the type.</p>
+
+  <p>May's Landing, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANOM&#x0152;ONEIS FOLLIS (EHR.)
+  CL.</span></p>
+
+  <p>Valve rhomboid, tumid in the middle and obtuse at the produced ends. Central area lanceolate;
+  striæ radiate in the middle, transverse at the ends.</p>
+
+  <p><i>Navicula follis</i> Ehr.</p>
+
+  <p><i>Navicula trochus</i> Kuetz.</p>
+
+  <div><span class="pagenum" id="page81">{81}</span></div>
+
+  <p>Reported by Lewis as very rare in the blue clay of the Delaware River. I have not seen it in
+  this locality. The figure is drawn from a specimen in the W. Bridgewater, Mass., deposit.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 14.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Caloneis</span> <span
+  class="smaller">CLEVE</span> (1894)</h4>
+
+  <p class="ac">(calos, beautiful)</p>
+
+  <p>Valve convex, linear or lanceolate in general outline, with transverse, smooth or finely
+  punctate striæ crossed by one or more longitudinal lines.</p>
+
+  <p class="sp3">Endochrome of two chromatophores lying one on each valve, entire in some species
+  and deeply cleft in others.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS LIBER (WM. SM.)
+  CL.</span></p>
+
+  <p>Valve linear, with parallel margins and rounded ends; axial area narrow, central area
+  orbicular; striæ transverse in the middle, slightly divergent at the ends, 16 in 10 µ; terminal
+  fissures slightly curved in the same direction; longitudinal line median. L. 82 µ.</p>
+
+  <p>Atlantic coast, chiefly southward.</p>
+
+  <p class="sp3">Pl. <a href="#plate40"><b>40</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS SILICULA (EHR.)
+  CL.</span></p>
+
+  <p>Valve linear, gibbous in the middle, with broad sub-cuneate ends; axial area narrow, central
+  area rounded; longitudinal line marginal; striæ parallel or nearly so, 16 to 18 in 10 µ.</p>
+
+  <p><i>Navicula silicula</i> Ehr.</p>
+
+  <p><i>Navicula limosa</i> Donk.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 3 (var. genuina Cl.).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS SILICULA VAR. INFLATA
+  (GRUN.) CL.</span></p>
+
+  <p>Valve gibbous in the middle, with rounded ends; central area elliptical.</p>
+
+  <p>Schuylkill River.</p>
+
+  <p>Pl. <a href="#plate21"><b>21</b></a>, Fig. 4.</p>
+
+  <p class="sp3">C. silicula may be recognized by its yellow color when dry. Its varieties are
+  extremely numerous.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS TRINODIS
+  (LEWIS)</span></p>
+
+  <p>Valve divided into three segments of equal width; ends cuneate and usually produced; axial area
+  elliptical with a lunate marking on each side; striæ radiate in the middle, elsewhere parallel,
+  about 20 in 10 µ, finely punctate; longitudinal line marginal, scarcely visible; the striæ become
+  fainter toward the axial area.</p>
+
+  <p>Occasional in streams and in the blue clay. Abundant in a water-trough at Ashbourne, Pa.</p>
+
+  <p>Pl. <a href="#plate21"><b>21</b></a>, Fig. 8.</p>
+
+  <p>I have retained Lewis' name as specific. Lewis, wrongly, I think, ascribes his species to
+  <i>Navicula trinodis</i> Wm. Sm., which is not figured by Smith, but is illustrated by Van Heurck
+  (Syn. Pl. 14, Fig. 31a), and is named by Cleve <i>Navicula contenta</i> var. <i>biceps</i> Arnott.
+  <span class="pagenum" id="page82">{82}</span>De Toni includes Lewis' name under <i>Rhoiconeis
+  trinodis</i> (Wm. Sm.) Grun. Rhoiconeis is achnanthiform, with frustules arcuate, and the species
+  is named by Cleve <i>Achnanthes trinodis</i> (Arnott). <i>Caloneis schumanniana</i> (Grun.) Cl.,
+  to which as a variety Cleve unites Lewis' form, appears to resemble it only in the lunate
+  marks.</p>
+
+  <p>Fig. 9 represents a single specimen found in the Pavonia deposit and which I believe to be an
+  abnormal form of C. trinodis, differing only in the degree of inflation and in the larger central
+  area.</p>
+
+  <p class="sp3"><i>Navicula trinodis</i> var. <i>inflata</i> Schultze, from Staten Island, is the
+  same form figured by Lewis, who states that certain specimens have produced apices.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS PERMAGNA (BAIL.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, with produced apices; median line nearly straight; axial area lanceolate,
+  irregular or slightly unilateral, about half the width of the valve; striæ, 9 in 10 µ, radiate and
+  indistinctly punctate; longitudinal lines double. L. 100-200 µ.</p>
+
+  <p><i>Pinnularia permagna</i> Bail.</p>
+
+  <p>Common in brackish water.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS PERMAGNA VAR. LEWISIANA
+  N. VAR.</span></p>
+
+  <p>Valve lanceolate, with undulating sides and sub-cuneate apices; axial area less than one-third
+  the width of the valve; striæ radiate, 12 in 10 µ, indistinctly punctate; longitudinal lines
+  double, closer together than in the type. L. 140 µ.</p>
+
+  <p>Lewis illustrates this variety in "New and Rare Species," Pl. 2, Fig. 11, and states that it is
+  probably Navicula esox Kuetzing. This is an error, as Kuetzing's species is Pinnularia esox Ehr.,
+  a form near P. major.</p>
+
+  <p>Rather common in the Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS FORMOSA (GREG.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, with sub-cuneate apices; axial area one-fourth to one-fifth the width of the
+  valve, somewhat unilateral, dilated in the middle; striæ, 12-14 in 10 µ radiate, punctate;
+  longitudinal lines double, distinct. Variable in size and outline.</p>
+
+  <p>Abundant along the shores of the Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS BREVIS VAR. VEXANS
+  (GRUN.) CL.</span></p>
+
+  <p>Valve elliptical-lanceolate; apices obtuse; median fissures distant; axial area narrow; central
+  area large, orbicular; longitudinal lines close together, median.</p>
+
+  <p>Shark River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS WARDII CL.</span></p>
+
+  <p>Valve linear, ends cuneate; axial area linear; central area dilated to a stauros reaching the
+  margin; striæ parallel, radiate at the ends, 18 in 10 µ; longitudinal lines marginal.</p>
+
+  <p>Not uncommon in the Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Figs. 6 and 7.</p>
+
+  <div><span class="pagenum" id="page83">{83}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CALONEIS POWELLII (LEWIS)
+  CL.</span></p>
+
+  <p>Valve linear, with cuneate ends; axial area linear; central area large, quadrate, united to the
+  wide longitudinal lines; striæ parallel, smooth, 8 in 10 µ.</p>
+
+  <p>Long Island (Lewis); Smith's Island, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 10.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Neidium</span> <span
+  class="smaller">PFITZER</span> (1871)</h4>
+
+  <p class="ac">(neidion, dim. of naus, a boat)</p>
+
+  <p>Valve linear or lanceolate; median fissures turned in opposite directions, terminal fissures
+  appearing bifurcate (?); striæ transverse, usually oblique, finely punctate, crossed by one or
+  several longitudinal blank lines.</p>
+
+  <p>Chromatophores, two, lying on the girdle side, in cell division each forming a partially
+  divided pair. A large pyrenoid is said to be found in the middle of each chromatophore, but
+  Mereschkowsky states that the pyrenoids are absent, but that in N. affine four elæoplasts are
+  always seen in the centre of the frustule.</p>
+
+  <p class="sp3">A genus easily recognized by the peculiar terminal and median fissures and by the
+  yellowish or brownish color of the valves when dry, darker than in Caloneis.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NEIDIUM AFFINE (EHR.)
+  PFITZER</span></p>
+
+  <p>Valve linear, with protracted, sub-rostrate or capitate ends.</p>
+
+  <p class="sp3"><i>Navicula affinis</i> Ehr.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NEIDIUM AFFINE VAR. GENUINA FORMA
+  MAXIMA CL.</span></p>
+
+  <p>Striæ, 14 in 10 µ, punctate, oblique in the middle, convergent at the ends; puncta, 15 in 10 µ.
+  L. 238 µ.</p>
+
+  <p>Pensauken, N. J. (artesian well).</p>
+
+  <p>Pl. <a href="#plate21"><b>21</b></a>, Fig. 11.</p>
+
+  <p>Var. genuina forma minor Cl.&mdash;L. 26 µ; striæ, 24 in 10 µ.</p>
+
+  <p>Brandywine Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NEIDIUM AFFINE VAR. AMPHIRHYNCUS
+  (EHR.) CL.</span></p>
+
+  <p>Valve linear, with protracted capitate ends; striæ transverse, interrupted by several
+  longitudinal lines.</p>
+
+  <p>Willistown, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NEIDIUM AMPHIGOMPHUS (EHR.)
+  PFITZER</span></p>
+
+  <p>Valve with parallel margins and cuneate ends; striæ transverse, interrupted by several
+  longitudinal lines; central area widened transversely.</p>
+
+  <p><i>Navicula amphigomphus</i> Ehr.</p>
+
+  <p>Wissahickon.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NEIDIUM PRODUCTUM (WM. SM.)
+  CL.</span></p>
+
+  <p>Valve linear, elongate, with capitate apices; striæ slightly oblique; longitudinal lines
+  marginal; axial area very narrow, central area small.</p>
+
+  <p><i>Navicula producta</i> Wm. Sm.</p>
+
+  <p>Newtown Square.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 16.</p>
+
+  <div><span class="pagenum" id="page84">{84}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NEIDIUM IRIDIS (EHR.)
+  CL.</span></p>
+
+  <p>Valve linear or lanceolate-elliptical, with sub-cuneate or rounded ends; striæ oblique, about
+  18 in 10 µ; central area orbicular.</p>
+
+  <p><i>Navicula iridis</i> Ehr.</p>
+
+  <p><i>Navicula firma</i> Kuetz.</p>
+
+  <p>Willistown, Pa.; Middletown, Delaware Co., Pa. (Palmer).</p>
+
+  <p>Pl. <a href="#plate21"><b>21</b></a>, Fig. 17.</p>
+
+  <p class="sp3">The form here figured is probably the variety ampliata (Ehr.) Cl. with less acute
+  apices and more elliptical outline. The species occurs in many variations, the larger being found
+  northward, especially in the peat deposits of New England.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NEIDIUM HITCHCOCKII (EHR.)
+  CL.</span></p>
+
+  <p>Valve linear, with triundulate margin and cuneate ends; striæ transverse, oblique.</p>
+
+  <p><i>Navicula hitchcockii</i> Ehr.</p>
+
+  <p>Pavonia, N. J. (artesian well); Kirkwood Pond, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate21"><b>21</b></a>, Fig. 15.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Diploneis</span> <span
+  class="smaller">EHR.</span> (1840)</h4>
+
+  <p class="ac">(diplos, double)</p>
+
+  <p>Valve elliptical or panduriform; median line enclosed in strongly siliceous horns corresponding
+  to the lyre-shaped areas of Navicula lyra but never punctate; central nodule, quadrate; valve
+  costate, or striate, or both; between the horns and the outer part are thinner spaces or sulci,
+  and, in some species, outside of the sulci are narrow spaces known as lunulæ.</p>
+
+  <p class="sp3">Chromatophores, two, upon the girdle or the valves. Pyrenoids have been found in
+  one species only, D. interrupta.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS ELLIPTICA (KUETZ.)
+  CL.</span></p>
+
+  <p>Valve elliptical; central nodule large; sulci narrow, curved, close to the horns; striæ
+  punctate, in rows radiating more and more toward the ends. Variable in size and in the coarseness
+  of puncta which are from 10 to 13 in 10 µ (Cleve).</p>
+
+  <p>Cleve describes D. ovalis Hilse as having the central nodule rounded, but otherwise about the
+  same as D. elliptica, and as equivalent to Navicula ovalis A. Schmidt (Atlas, Pl. 7, Figs. 33 to
+  36).</p>
+
+  <p>Very common in fresh water and occasional in brackish.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS SMITHII (BRÉB.)
+  CL.</span></p>
+
+  <p>Valve elliptical; central nodule not broad; furrows evenly curved on the outer edge, crossed by
+  costæ and double oblique rows of alveoli. Variable in size and in the curvature of the
+  furrows.</p>
+
+  <p>Cleve forms a new species, D. major, of the large form figured by Schmidt (Atlas, Pl. 7, Figs.
+  18, 19, 21 and 22), stating that the structure is much coarser and the form is larger with broad
+  furrows. In the specimen here figured the size is median and the furrows are as in D. major.</p>
+
+  <p>Marine and brackish. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 17.</p>
+
+  <div><span class="pagenum" id="page85">{85}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS CRABRO VAR. PANDURA
+  (BRÉB.) CL.</span></p>
+
+  <p>Valve constricted, segments tongue-shaped; central nodule small; horns narrow, nearly parallel,
+  with a row of large puncta; costæ, 4 in 10 µ, convergent in the middle, radiating at the ends,
+  alternating with a double row of puncta, 11 in 10 µ.</p>
+
+  <p>Pavonia, N. J. (artesian well).</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS CRABRO VAR. EXPLETA (A.
+  S.) CL.</span></p>
+
+  <p>Valve slightly constricted, segments tongue-shaped; costæ robust, 5 or 6 in 10 µ, alternating
+  with double rows of rather coarse puncta. L. 56 µ.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS CRABRO VAR. PANDURELLA
+  CL.?</span></p>
+
+  <p>Valve constricted, the lobes elliptical; central nodule large, with horns parallel in the
+  middle, convergent at the ends; furrows wide, with faint costæ; no lunula; costæ parallel in the
+  middle, radiate at the ends, 9 in 10 µ, alternating with very fine double rows of puncta (not
+  shown in the figure). L. 65 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS CRABRO VAR.?</span></p>
+
+  <p>Valve constricted, segments elliptical; costæ, 8 in 10 µ, converging in the middle, radiating
+  at the ends; horns narrow; furrows wide, costate; lunulæ indistinct. L. 75 µ.</p>
+
+  <p>Resembles var. pandurella except in the convergence of the costæ and in the lunula.</p>
+
+  <p>Squan River. Marine.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS FUSCA VAR. DELICATA (A.
+  S.) CL.</span></p>
+
+  <p>Valve elliptical; furrows broad, crossed with rows of faint costæ and alveoli; costæ, 6 or 7 in
+  10 µ; alveoli, 10 in 10 µ, in short, irregular, longitudinal rows. L. 84 µ.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS GRUENDLERI (A. S.)
+  CL.</span></p>
+
+  <p>Valve constricted, segments tongue-shaped, often unequal; horns broad, divergent in the middle;
+  furrows narrow; costæ transverse, crossed by from 3 to 7 longitudinal costæ, interrupted in the
+  middle at the border.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Figs. 7 and 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS PUELLA (SCHUM.)
+  CL.</span></p>
+
+  <p>Valve elliptical, sometimes orbicular; furrows very narrow; striæ, 20 in 10 µ, indistinct. L.
+  15 µ.</p>
+
+  <p><i>Diploneis elliptica</i> var. <i>minutissima</i> Grun.</p>
+
+  <p>Shark River, N. J. Brackish.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS EXCENTRICA, N.
+  SP.</span></p>
+
+  <p>Valve elliptical; central nodule quadrate; furrows of the same width throughout, nearly
+  parallel; costæ radiating toward the ends, 10 in 10 µ, indistinct on the furrows, alternating with
+  alveoli, 7 in 10 µ, in irregular, longitudinal lines. One side of the valve is one and a half
+  times the width of the other. L. 49 µ.</p>
+
+  <div><span class="pagenum" id="page86">{86}</span></div>
+
+  <p>I can find neither description nor figure of any species to which I can ascribe this form. It
+  approaches D. elliptica. The alveoli are quite distinct and distant from each other.</p>
+
+  <p>Brackish water. Very abundant in a gathering from Squan River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS OCULATA (BRÉB.)
+  CL.</span></p>
+
+  <p>Valve elliptical; striæ radiate at the ends, about 20 in 10 µ, coarsely punctate. L. 23 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p>Pl. <a href="#plate26"><b>26</b></a>, Fig. 7.</p>
+
+  <p>The figure is drawn from Brébisson's original material in H. L. Smith's Type Slide No. 299.</p>
+
+  <p><i>Navicula oculata</i> Bréb.</p>
+
+  <p class="sp3">Reported from New Jersey. I have not seen this species in this locality. Navicula
+  oculata, referred to by Kain as occurring in Shark River, is not this form.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS GEMMATA (GREV.)
+  CL.</span></p>
+
+  <p>Valve oblong-linear, with cuneate ends and parallel or slightly concave sides; central nodule
+  large; horns parallel; furrows about one-third the width of the valve. Costæ about 5 in 10 µ,
+  alternating with double rows of fine puncta; short costæ occur along the borders of the horns.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">DIPLONEIS CAMPYLODISCUS (GRUN.)
+  CL.</span></p>
+
+  <p>Valve suborbicular; central nodule quadrate; horns divergent; costæ, 6 in 10 µ, alternating
+  with double rows of alveoli; furrows broad, costate near the horns.</p>
+
+  <p>Differs from Cleve's description in having 6, instead of 4, costæ in 10 µ.</p>
+
+  <p>Pensauken, N. J. (artesian well). Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate20"><b>20</b></a>, Fig. 6.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Mastogloia</span> <span
+  class="smaller">THWAITES</span> (1856)</h4>
+
+  <p class="ac">(mastos, a breast, and gloios, gelatinous, referring to the "mamillate cushion" in
+  which the frustules are often immersed)</p>
+
+  <p class="sp3">Frustule rectangular. Valves similar, naviculoid. Central and axial areas usually
+  narrow or indistinct; striæ punctate, parallel in the middle. On each side, between the valve and
+  the zone, is a septate plate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">ANALYSIS OF SPECIES</span></p>
+
+  <table class="sp2 mc w50" title="Species of Mastogloia" summary="Species of Mastogloia">
+    <tr class="pb05">
+      <td class="itp05">Striæ interrupted by a hyaline furrow on each side of the median line</td>
+      <td class="vbm">kinsmanii</td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="2">Striæ not interrupted:</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2">Loculi, five, or less</td>
+      <td class="vbm">exigua</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="hid">Loculi,</span> more than five, equal, ending at distance
+      from the ends</td>
+      <td class="vbm">smithii</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="hid">Loculi,</span> ending near the ends, distinct</td>
+      <td class="vbm">lanceolata</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="hid">Loculi, ending near the ends,</span> indistinct</td>
+      <td class="vbm">elegans</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="hid">Loculi,</span> very numerous</td>
+      <td class="vbm">apiculata</td>
+    </tr>
+    <tr class="pb05">
+      <td class="pl2"><span class="hid">Loculi,</span> unequal</td>
+      <td class="vbm">angulata</td>
+    </tr>
+  </table>
+
+  <div><span class="pagenum" id="page87">{87}</span></div>
+
+  <p class="sp3">Karsten states that there are two chromatophores, each of which extends from the
+  middle of one valve to the end and down the middle of the other valve. Mereschkowsky says,
+  however, that there are four plates or chromatophores, sometimes on the valve, sometimes on the
+  zone, according to the species, and that two long pyrenoids unite the two opposite
+  chromatophores.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MASTOGLOIA KINSMANII
+  LEWIS</span></p>
+
+  <p>Valve lanceolate-elliptical, with sub-rostrate ends; loculi more numerous than in M. angulata
+  but less than in M. apiculata, the middle ones larger. Median line with a sulcus on each side;
+  central area quadrate.</p>
+
+  <p><i>Mastogloia braunii</i> Grun. (According to Cleve).</p>
+
+  <p>Atlantic City.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MASTOGLOIA EXIGUA
+  LEWIS</span></p>
+
+  <p>Valve elliptical- or linear-lanceolate; loculi, 2-5, usually 3, larger in the middle and
+  rounded; central space small; striæ, 20-24 in 10 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 24.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MASTOGLOIA SMITHII
+  THWAITES</span></p>
+
+  <p>Valve lanceolate, sub-rostrate; loculi forming a wide band ending at a distance from the ends;
+  striæ transverse, with puncta forming longitudinal rows; central area rounded or transversely
+  elliptical.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MASTOGLOIA LANCEOLATA
+  THWAITES</span></p>
+
+  <p>Valve lanceolate, with sub-rostrate apices; loculi very numerous; median and central areas
+  indistinct; striæ, 19 in 10 µ, punctate, convergent at the ends.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MASTOGLOIA ELEGANS
+  LEWIS</span></p>
+
+  <p>Valve lanceolate, acute; loculi indistinct or rudimentary, extending to the ends; central area
+  apparently quadrate, sometimes indistinct; puncta distinct, 15 in 10 µ, in transverse and
+  longitudinal rows.</p>
+
+  <p>Along the coast. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 20.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MASTOGLOIA APICULATA WM.
+  SM.</span></p>
+
+  <p>Valve elliptical-lanceolate, sometimes with slightly produced apices; median line between two
+  ribs; central space very small; loculi numerous; puncta in slightly radiating rows and in
+  longitudinal lines.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Figs. 21, 22, 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">MASTOGLOIA ANGULATA
+  LEWIS</span></p>
+
+  <p>Valve elliptical, with produced apices; loculi usually less than 12, unequal, the larger in the
+  middle; striæ, 12 in 10 µ, puncta in decussating rows. "Differs from apiculata in its more broadly
+  elliptical shape, the smaller number of its loculi and the angular character of its striation"
+  (Lewis).</p>
+
+  <div><span class="pagenum" id="page88">{88}</span></div>
+
+  <p>Considered by Cleve as synonymous with M. apiculata Grun., not Wm. Smith, and by De Toni as
+  synonymous with M. apiculata Wm. Sm. In any case, M. angulata Lewis is not the same as M.
+  apiculata Wm. Sm., the loculi of which are equal.</p>
+
+  <p>Atlantic City. H. L. Smith T. S. No. 211.</p>
+
+  <p class="sp3">Pl. <a href="#plate17"><b>17</b></a>, Fig. 17.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Stauroneis</span> <span
+  class="smaller">EHR.</span> (1843)</h4>
+
+  <p class="ac">(stauros, a cross, and neis (naus), a boat)</p>
+
+  <p>Frustules free, sometimes geminate; valve as in Navicula but with a stauros. Cell contents as
+  in Navicula. Mereschkowsky, however, says that the chromatophores always contain more pyrenoids
+  than are found in Navicula. Heinzerling gives the number as two to four in each chromatophore.</p>
+
+  <p>Cleve includes under Naviculæ Microstigmaticæ all species of Stauroneis, Pleurostauron,
+  Schizostauron, certain Schizonemæ and Naviculæ. As a matter of convenience, and because I have
+  already included certain Schizonemæ and Scoliopleura under Navicula, and because of the small
+  number of species in our locality, I have arranged them under the three divisions of Cleve as
+  follows:</p>
+
+  <p><i>Stauroneis.</i>&mdash;Forms having a true stauros, without diaphragms.</p>
+
+  <p><i>Pleurostauron.</i>&mdash;Forms like Stauroneis but with diaphragms at the ends.</p>
+
+  <p class="sp3"><i>Schizostauron.</i>&mdash;Forms having a bifid stauros.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS PH&#x0152;NICENTERON
+  EHR.</span></p>
+
+  <p>Valve lanceolate, obtuse; striæ radiate, 18 in 10 µ, distinctly punctate. L. usually 125 µ but
+  sometimes 200 µ.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS ANCEPS EHR.</span></p>
+
+  <p>Valve lanceolate, with rostrate or capitate ends; stauros in some cases does not reach the
+  margin. The varieties are very numerous.</p>
+
+  <p><i>Var. gracilis (Ehr.) Cl.</i>&mdash;Valve lanceolate, striæ very fine; margin of stauros
+  striated. L. 100 µ. Cape May, N. J. Pl. <a href="#plate27"><b>27</b></a>, Fig. 5.</p>
+
+  <p><i>Var. amphicephala (Kuetz.) Cl.</i>&mdash;Valve capitate at the ends; striæ, 24 in 10 µ. L.
+  47 µ. Fresh water. Pl. <a href="#plate27"><b>27</b></a>, Fig. 7.</p>
+
+  <p><i>Var. ?</i>&mdash;Valve with produced ends; striæ, 30 or more in 10 µ. L. 104 µ. Willistown,
+  Pa. Pl. <a href="#plate27"><b>27</b></a>, Fig. 4.</p>
+
+  <p><i>Var. ?</i>&mdash;Valve with produced ends; striæ, about 28 in 10 µ, punctate. L. 47 µ.
+  Newtown Square. Pl. <a href="#plate27"><b>27</b></a>, Fig. 8.</p>
+
+  <p class="sp3"><i>Var. ?</i>&mdash;Valve with produced ends; striæ, 22 in 10 µ, showing a tendency
+  to form longitudinal rows of puncta as in Stauroneis stodderi Greenleaf, but the rows are not so
+  evident. L. 60 µ. Pavonia, N. J., artesian well. Pl. <a href="#plate27"><b>27</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS FRICKEI VAR. ANGUSTA
+  N. VAR.</span></p>
+
+  <p>Valve lanceolate, gradually tapering to the obtuse ends; terminal fissures prominent, forking
+  at a distance of 7 µ from the ends. Frustules frequently geminate. L. 173 µ.</p>
+
+  <p>Newtown Square. Rare.</p>
+
+  <p>Pl. <a href="#plate26"><b>26</b></a>, Fig. 18.</p>
+
+  <p class="sp3">Near Stauroneis frickei A. S. (Atlas, Pl. 242, Fig. 16), except that the stauros is
+  narrow at the margin.</p>
+
+  <div><span class="pagenum" id="page89">{89}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS SALINA WM.
+  SM.</span></p>
+
+  <p>Valve lanceolate, obtuse; stauros narrow, with short, scattered striæ at the margin, 18 in 10
+  µ, punctate. L. 65 µ.</p>
+
+  <p>Along the coast. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS LEGUMEN
+  EHR.</span></p>
+
+  <p>Valve elliptical-lanceolate, inflated in the middle, with produced sub-capitate or rostrate
+  ends separated by diaphragms. Stauros wide, striated at the margins; axial area very narrow; striæ
+  radiate, about 26 (?) in 10 µ, punctate. L. 28 µ.</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p>Pl. <a href="#plate39"><b>39</b></a>, Fig. 15.</p>
+
+  <p class="sp3">In Cleve's description and Van Heurck's figure, the median inflation is "not larger
+  than the others." In the present form the median inflation is wider.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS ACUTA WM.
+  SM.</span></p>
+
+  <p>Valve rhombic-lanceolate, obtuse; a diaphragm at each end; stauros widened outwards; striæ, 15
+  or 16 in 10 µ, punctate. L. 130 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS AMERICANA A.
+  S.</span></p>
+
+  <p>Valve elliptical-lanceolate, obtuse; striæ, 14 in 10 µ. L. 119 µ.</p>
+
+  <p>Pavonia, N. J., artesian well. Rare.</p>
+
+  <p>The only specimen found is asymmetrical with respect to the transverse axis.</p>
+
+  <p class="sp3">On Plate <a href="#plate40"><b>40</b></a>, Fig. 4, is illustrated an abnormal form
+  of Stauroneis, apparently near S. acuta, having an elongated central nodule and radiating, curved
+  and coarsely punctate striæ. Blue clay.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS SMITHII
+  GRUN.</span></p>
+
+  <p>Valve lanceolate, inflated in the middle and at the ends, which have diaphragms and are
+  produced into rostrate apices; stauros reaching the margin; striæ parallel, about 25 in 10 µ (28
+  to 30, Cleve), distinctly punctate.</p>
+
+  <p>Not uncommon in meadow pools near Newtown Square.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">STAURONEIS CRUCICULA (GRUN.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, with obtuse, produced ends; stauros bifid; striæ, 24 in 10 µ, oblique,
+  parallel to the branches of the stauros, closer at the ends, punctate. L. 32 µ.</p>
+
+  <p>Newtown Square. East Park Reservoir. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 10.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Navicula</span> <span
+  class="smaller">BORY</span> (1826)</h4>
+
+  <p class="ac">(dim. of navis, a boat)</p>
+
+  <p>Valve linear to elliptical; ends acute, rounded, rostrate, capitate or truncate; axial area
+  usually distinct; central area distinct, rounded or rarely extended into a transverse fascia;
+  striæ transverse or radiate, punctate; central area not dilated into a transverse stauros nor into
+  horns.</p>
+
+  <div><span class="pagenum" id="page90">{90}</span></div>
+
+  <p>The endochrome in the greater number of species consists of two chromatophores extending along
+  the zone and sometimes partly over the valves. Sometimes, however, as in N. hennedyi, N. lyra and
+  N. humerosa, the bands are on the valves. Certain species have four bands, others eight, and in
+  one the endochrome is granular. (Mereschkowsky, l. c., p. 9 et seq.) Pyrenoids are usually absent.
+  On account of the diversity of the chromatophores, Mereschkowsky considers the genus not
+  homogeneous. The difficulty of arranging groups according to the cell contents, however, is so
+  great that, for the present, the species must be described by the usual characteristics of the
+  valves and divided as follows, according to Cleve, to the extent of employing the classification
+  of all Naviculoid forms as applicable, especially to the species of Navicula. Van Heurck's
+  analysis includes Pinnularia, Trachyneis, Diploneis, Caloneis, Neidium and Anom&#x0153;oneis,
+  which are here separated, while N. lyra and N. hennedyi are placed in different groups, although
+  they are closely related. In other respects Cleve's divisions correspond, to some extent, to those
+  of Van Heurck.</p>
+
+  <p>The genus Navicula at one time included the following: Dictyoneis, Pleurosigma, Gyrosigma,
+  Caloneis, Neidium, Diploneis, Frustulia, Trachyneis, Anom&#x0153;oneis, Pinnularia and Stauroneis,
+  and few forms with a raphe escaped. For this reason the diagnosis of the present genus is somewhat
+  limited. Pleurosigma and Gyrosigma differ from Navicula in their outline, Dictyoneis in the double
+  stratification, Caloneis in the marginal lines, Neidium in the median and terminal fissures,
+  Diploneis in the horns, Frustulia in the terminal nodules, Trachyneis in the stratification of the
+  valve, Anom&#x0153;oneis in the longitudinal arrangement of the puncta, Pinnularia in the smooth
+  costæ and Stauroneis in the stauros.</p>
+
+  <p class="sp3">As the object of the present work is to aid the student of local forms in the
+  identification of species by the briefest methods, the further discussion of the reasons for
+  classification will be left for his gratification in referring to the authorities on the
+  subject.</p>
+
+  <p class="ac"><span class="sc">Punctatæ Cleve</span></p>
+
+  <p class="sp3">Valve elliptical to lanceolate; central nodule not stauroid or continued into
+  lyriform spaces; striæ distinctly or coarsely punctate, in radiate rows.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA MACULATA (BAIL.)
+  CL.</span></p>
+
+  <p>Valve lanceolate-elliptical, with produced or sub-rostrate ends; axial area narrow, wider near
+  the ends and dilated to a rounded, transverse central area; striæ radiate, 6 in 10 µ, puncta, 7 in
+  10 µ, in irregular, longitudinal rows. L. 90 to 120 µ (Cl.).</p>
+
+  <p><i>Stauroneis maculata</i> Bail.</p>
+
+  <p><i>Navicula fischeri</i> A. S.</p>
+
+  <p>Blue clay. Along the coast, especially southward.</p>
+
+  <p class="sp3">Pl. <a href="#plate24"><b>24</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA LATISSIMA
+  GREG.</span></p>
+
+  <p>Valve oblong-elliptical or elliptical-lanceolate, with sub-cuneate ends; axial area lanceolate,
+  widened in the middle to an orbicular space; striæ radiate, 7 in 10 µ, puncta, 11 in 10 µ, the
+  median striæ alternating with short striæ along the sides. L. 50-150 µ (Cl).</p>
+
+  <p>Blue clay. Pavonia, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate24"><b>24</b></a>, Fig. 3.</p>
+
+  <div><span class="pagenum" id="page91">{91}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA LATISSIMA VAR. ELONGATA
+  (PANT.) CL.</span></p>
+
+  <p>Valve elliptical-lanceolate, with rounded ends; striæ and puncta closer than in the type form;
+  axial area narrow, widened in the middle; terminal fissures hook-shaped, turned in different
+  directions.</p>
+
+  <p><i>Navicula humerosa</i> var. <i>elongata</i> Pant.</p>
+
+  <p>Fossil at Buckshutem, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate24"><b>24</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA FUCHSII PANT.</span></p>
+
+  <p>Valve elliptical, with slightly produced apices; axial area wide, lanceolate; central area
+  orbicular; striæ alternately longer and shorter in the middle, 10-12 in 10 µ; puncta on the border
+  of the axial area larger, elongated; median fissures incrassate.</p>
+
+  <p><i>Navicula humerosa</i> var. <i>fuchsii</i> (Pant.) Cl.</p>
+
+  <p><i>Navicula</i> (<i>latissima</i> var.?) <i>fuchsii</i> Pant.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate24"><b>24</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA HUMEROSA
+  BRÉB.</span></p>
+
+  <p>Valve lanceolate-elliptical or oblong-elliptical, with sub-cuneate or sub-rostrate ends; axial
+  area narrow, lanceolate; central area rounded, somewhat transverse; terminal fissures hook-shaped,
+  in the same direction; central pores incrassate; striæ, 11 in 10 µ, the middle alternately longer
+  and shorter, closer at the ends. L. 60-86 µ. Variable in size, outline and fineness of
+  striation.</p>
+
+  <p>N. monilifera Cleve (N. granulata Bréb.) differs in having coarser striæ.</p>
+
+  <p>Blue clay. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate25"><b>25</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PUSILLA WM.
+  SM.</span></p>
+
+  <p>Valve ovate-elliptical, with rostrate or sub-rostrate ends; axial area narrow; central area
+  elliptical; striæ radiate, 10-12 in 10 µ in the middle where they are longer and shorter
+  alternately, closer at the ends; median fissures somewhat incrassate, terminal in the same
+  direction. L. 47 µ.</p>
+
+  <p>Smith's Island, Delaware River.</p>
+
+  <p>Pl. <a href="#plate25"><b>25</b></a>, Figs. 4, 6?</p>
+
+  <p>Cleve gives the striæ as 13-18 in the typical form, and 11-13 in varieties. In the form here
+  figured the striation is as stated by De Toni, but is about 19 at the ends.</p>
+
+  <p class="sp3">Fig. 6 appears to be a small form of N. pusilla, near lanceolata Grun., at least
+  according to the figure in "Arctic Diatoms," but not Gregory's figure. It occurs rarely in fresh
+  water at Newtown Square. It may be a small form of N. punctulata and, if so, is probably
+  accidental, as the material is entirely fresh-water.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PUSILLA VAR. SUBCAPITATA
+  N. VAR.</span></p>
+
+  <p>Valve elliptical with rostrate-capitate and truncate ends; striæ about 12 in 10 µ in the middle
+  where they are unequal; axial area narrow, slightly widened in the middle; central pores
+  incrassate, terminal fissures in the same direction. Differs from type in outline and centre.</p>
+
+  <p>Pavonia, N. J., artesian well. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate25"><b>25</b></a>, Fig. 8.</p>
+
+  <div><span class="pagenum" id="page92">{92}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA DELAWARENSIS
+  GRUN.</span></p>
+
+  <p>Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow, lanceolate, widened in
+  the middle; striæ about 10 in 10 µ; in the middle, much closer at the ends; puncta in the middle,
+  9 in 10 µ, closer and much smaller at the ends. L. 58-95 µ.</p>
+
+  <p>Cleve (Le Diatomiste, Vol. 2, p. 14) states that this form is very near N. pusilla but is much
+  larger. Specimens from Smith's Island measure 58-65 µ, from Wildwood, 95 µ in length.</p>
+
+  <p class="sp3">Pl. <a href="#plate25"><b>25</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PUNCTULATA WM.
+  SM.</span></p>
+
+  <p>Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow, central area rounded;
+  striæ, 11 in 10 µ, closer at the ends, a few shorter in the middle; puncta, 10 in 10 µ. L. 54
+  µ.</p>
+
+  <p><i>Navicula marina</i> Ralfs.</p>
+
+  <p>Port Penn, Delaware River (brackish water).</p>
+
+  <p>Pl. <a href="#plate25"><b>25</b></a>, Fig. 9.</p>
+
+  <p class="sp3">"Although this species is described as marine in the Synopsis of Prof. Smith, I
+  have never found it in purely marine localities" (Donkin).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PUNCTATA VAR.
+  ASYMMETRICA LAGERSTEDT</span></p>
+
+  <p>Valve lanceolate, with rostrate ends; axial area narrow, central area transverse, irregular;
+  striæ radiate, punctate, 12 in 10 µ. L. 36 µ.</p>
+
+  <p><i>Navicula amphibola</i> Cleve.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA BRASILIENSIS VAR.
+  BICUNEATA CL., FORMA CONSTRICTA</span></p>
+
+  <p>Valve oblong-elliptical, slightly constricted, with cuneate-rostrate ends; axial area narrow;
+  central area dilated transversely and unilaterally; striæ, 9 in 10 µ; puncta closer at the border
+  and in irregular longitudinal rows in the middle; terminal fissures small, hook-shaped, turned in
+  the same direction. L. 93 µ.</p>
+
+  <p>Corresponds closely to Cleve's variety except in the constriction.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate25"><b>25</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA LACUSTRIS
+  GREG.</span></p>
+
+  <p>Valve lanceolate, sub-acute; axial area narrow; central area orbicular; striæ radiate, 14 in 10
+  µ, punctate, the median puncta sometimes more distant than the others.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 12.</p>
+
+  <p class="ac"><span class="sc">Lyratæ Cl.</span></p>
+
+  <p class="sp3">Valve elliptical or elliptical-lanceolate; striæ punctate, transverse; axial area
+  narrow or indistinct; central area expanded on each side into lyre-shaped or horn-like blank
+  spaces.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PRÆTEXTA EHR.</span></p>
+
+  <p>Valve elliptical; lateral areas not regular, with scattered puncta; striæ radiate, 5 or 6 in 10
+  µ; puncta, 7 or 8 in 10 µ; along the axial area, a single or double row of puncta; at <span
+  class="pagenum" id="page93">{93}</span>the middle of the border, on each side, two striæ approach
+  each other closely with a short stria between them; terminal fissures small, in the same
+  direction. L. 120 µ.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p>Pl. <a href="#plate24"><b>24</b></a>, Fig. 2.</p>
+
+  <p class="sp3">While variable in size and striation, approaching N. hennedyi, this species, as
+  here figured, is found in the Miocene and later deposits and is extant in most parts of the
+  world.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA IRRORATA
+  GREV.</span></p>
+
+  <p>Valve oblong-elliptical, with cuneate-rostrate ends; striæ, 7 or 8 in 10 µ, puncta, 7 in 10 µ;
+  axial area bordered by puncta in unequal, transverse rows. L. 84 µ.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate24"><b>24</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA HENNEDYI WM.
+  SM.</span></p>
+
+  <p>Valve elliptical; areas semilanceolate; striæ about 11 in 10 µ, sometimes longer and shorter on
+  the margin; short rows of transverse striæ along the axial area.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate25"><b>25</b></a>, Fig. 12.</p>
+
+  <p><i>Var. circumsecta Grun.</i>&mdash;As in the type but with the lateral areas faintly striate
+  or punctate.</p>
+
+  <p><i>Var. manca A. S.</i>&mdash;Valve lanceolate-elliptical, the lateral areas narrow and
+  convergent toward the ends; short rows of transverse striæ along the axial area; striæ, 9 in 10 µ;
+  central pores incrassate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate25"><b>25</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA LYRA EHR.</span></p>
+
+  <p>Valve elliptical, with rounded, sub-rostrate or sub-cuneate ends; lateral areas narrow; striæ,
+  6 to 14 in 10 µ (Cl.), punctate. L. 50-180 µ.</p>
+
+  <p><i>Var. ehrenbergii Cl.</i>&mdash;Lateral areas constricted in the middle, divergent at the
+  ends. Cleve refers to Schmidt, Atlas, Pl. 2, Fig. 25, which is not divergent at the ends.</p>
+
+  <p>Along the coast.</p>
+
+  <p>Pl. <a href="#plate25"><b>25</b></a>, Fig. 10.</p>
+
+  <p>A narrower form occurs which has the areas divergent.</p>
+
+  <p><i>Var. ?</i>&mdash;Valve elliptical, lateral areas narrow, convergent at the ends with short
+  rows of punctate striæ; marginal striæ, 10 in 10 µ, punctate. L. 60 µ.</p>
+
+  <p>Squan River, N. J.</p>
+
+  <p>Pl. <a href="#plate20"><b>20</b></a>, Fig. 5.</p>
+
+  <p><i>Var. dilatata A. S.</i>&mdash;Valve elliptical, rostrate; lateral areas convergent in the
+  middle and nearly parallel or convergent at the ends.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate25"><b>25</b></a>, Fig. 13.</p>
+
+  <p class="sp3">N. lyra is exceedingly variable in outline, fineness of striation and in the
+  lateral areas. Intermediate forms occur approaching N. hennedyi and N. spectabilis. In N. hennedyi
+  the lateral areas are broad, semilanceolate, not narrowed in the middle. In N. spectabilis the
+  lateral areas are broad and narrowed in the middle. In N. lyra the lateral areas are narrow and
+  either constricted or not in the middle. In many forms in <span class="pagenum"
+  id="page94">{94}</span>these three species the lateral areas are more or less striated or
+  punctate. Cleve does not consider this a distinction of any importance, although certain varieties
+  are founded upon it. All three species are very common in the blue clay and along the coast, but
+  their varieties are too numerous to describe or figure.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA SPECTABILIS VAR.
+  EMARGINATA CL.</span></p>
+
+  <p>Valve elliptical; lateral areas broad, narrowed in the middle, delicately striated; marginal
+  striæ, 10 in 10 µ. L. 70 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate25"><b>25</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PYGMÆA KUETZ.</span></p>
+
+  <p>Valve elliptical, appearing hyaline; axial and central areas faint; lateral areas convergent in
+  the middle; striæ indistinct, about 25 in 10 µ. L. 23 µ.</p>
+
+  <p>Brandywine Creek (Palmer).</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 23.</p>
+
+  <p class="ac"><span class="sc">Decussatæ Cl.</span></p>
+
+  <p class="sp3">Valve elliptical or lanceolate; axial area narrow; central area small; striæ
+  punctate, in transverse and oblique, curved rows.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PLACENTA EHR.</span></p>
+
+  <p>Valve elliptical, with short, rostrate-capitate ends; axial area narrow; central area
+  elliptical; striæ in two directions, the transverse about 22 (to 27, Cl.) in 10 µ, the oblique
+  striæ crossing in both directions in curved lines appearing "coarser than the transverse"
+  (Lewis).</p>
+
+  <p>A very peculiar species which, as Cleve remarks, seems not to be allied to any other. L. about
+  35 µ, quite constant in size. It is reported from Finland, Scotland, Hungary and New Zealand. Dr.
+  Lewis found it in the Delaware River. It is occasional in the Schuylkill River and the blue clay,
+  and very abundant on Marchantia and mosses on the wet rocks of the upper Wissahickon (F. J.
+  Keeley).</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 17.</p>
+
+  <p class="ac"><span class="sc">Lineolatæ Cl.</span></p>
+
+  <p class="sp3">Valve more or less lanceolate; axial area narrow or indistinct; striæ radiate or
+  parallel, lineate, that is, with the puncta closer than the striæ.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA RADIOSA
+  KUETZ.</span></p>
+
+  <p>Valve lanceolate with sub-rostrate apices; axial area indistinct; central area small; striæ
+  radiate in the middle, from 6 to 8 in 10 µ, and convergent at the ends, about 12 in 10 µ. L. 47
+  µ.</p>
+
+  <p>Very common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 17; Pl. <a
+  href="#plate40"><b>40</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PEREGRINA
+  EHR.</span></p>
+
+  <p>Valve lanceolate, obtuse; axial area narrow; central area large, rounded or slightly irregular;
+  striæ coarse in the middle, 5 in 10 µ, radiate; convergent at the ends, 7 or 8 in 10 µ.</p>
+
+  <p>Abundant in brackish water. Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 20.</p>
+
+  <div><span class="pagenum" id="page95">{95}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA CYPRINUS (WM.
+  SM.)</span></p>
+
+  <p>Valve lanceolate, slightly gibbous in the middle, sub-cuneate at the ends; axial area narrow;
+  central area small; striæ radiate in the middle, 10 in 10 µ, with shorter, transverse striæ
+  intermediate; transverse at the extreme ends. L. 82 µ.</p>
+
+  <p><i>Navicula digito-radiata</i> var. <i>cyprinus</i> (Ehr. ?) Wm. Sm. Whether the form here
+  figured is Ehrenberg's or not, it is the species known as Pinnularia cyprinus Ehr. of Wm.
+  Smith.</p>
+
+  <p>Common in Shark River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA REINHARDTII
+  GRUN.</span></p>
+
+  <p>Valve elliptical or elliptical-lanceolate, with broad, rounded ends; axial area narrow, widened
+  at the ends to the width of the valve; central area widened transversely to an irregular, quadrate
+  space; striæ coarse, 8 in 10 µ, distinctly lineate, alternately longer and shorter in the middle,
+  radiate, nearly transverse at the ends. L. 59 µ.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 22.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA LANCEOLATA VAR. ARENARIA
+  (DONK.) CL.</span></p>
+
+  <p>Valve lanceolate; axial area very narrow or indistinct; central area small, rounded; striæ
+  radiate, 11 in 10 µ in the middle, closer at the ends. L. 47-54 µ.</p>
+
+  <p><i>Navicula arenaria</i> Donk.</p>
+
+  <p>Shark River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA SALINARUM
+  GRUN.</span></p>
+
+  <p>Valve elliptical-lanceolate with produced sub-capitate or rostrate ends; striæ radiate in the
+  middle, longer and shorter; transverse at the ends, lineate. L. 32 µ.</p>
+
+  <p>Atlantic City, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 24.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA VIRIDULA VAR. ROSTELLATA
+  KUETZ.</span></p>
+
+  <p>Valve lanceolate with rostrate ends; axial area very narrow, central area orbicular; striæ
+  radiate in the middle, about 12 in 10 µ, convergent at the ends and closer. L. 43 µ.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA GRACILIS VAR.
+  SCHIZONEMOIDES (EHR.) V. H.</span></p>
+
+  <p>Valve lanceolate, obtuse; axial area widened in the middle; striæ radiate in the middle, about
+  12 in 10 µ, transverse or slightly convergent at the ends. L. 45-60 µ. Occurs in gelatinous tubes;
+  usually found free.</p>
+
+  <p><i>Colletonema neglectum</i> Thwaites.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA RAMOSISSIMA (AG.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, sub-acute; axial area very narrow; central area scarcely widened; striæ, 12
+  in 10 µ, parallel throughout. L. 45 µ.</p>
+
+  <p><i>Micromega ramosissimum</i> Ag.</p>
+
+  <p><i>Schizonema smithii</i> Kuetz. (not Ag.).</p>
+
+  <p>East River, N. Y.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 14.</p>
+
+  <div><span class="pagenum" id="page96">{96}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA ANGLICA RALFS</span></p>
+
+  <p>Valve elliptical, with sub-capitate or rostrate ends; axial area narrow, central area small;
+  striæ radiate, 12-13 in 10 µ, distinctly punctate. L. 26 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 26.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA GASTRUM EHR.</span></p>
+
+  <p>Valve elliptical, with rostrate ends; axial area narrow, central area transverse or irregular;
+  striæ radiate, 9 in 10 µ in the middle. L. 26 µ.</p>
+
+  <p>The form here figured approaches N. anglica.</p>
+
+  <p>Kirkwood Pond, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 25.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA DICEPHALA WM.
+  SM.</span></p>
+
+  <p>Valve linear, with rostrate or rostrate-capitate ends; axial area narrow, central area
+  rectangular, transverse; striæ radiate, 12 in 10 µ. L. 32 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA HUMILIS DONK.</span></p>
+
+  <p>Valve elliptical, with broad, rostrate ends; axial area narrow; central area small; striæ
+  radiate and distant in the middle, convergent at the ends, coarse, appearing costate, averaging 9
+  in 10 µ. L. 19 µ. As Donkin states, the striæ are "very conspicuous."</p>
+
+  <p><i>Navicula hungarica</i> var. <i>capitata</i> (Ehr.) Cl.</p>
+
+  <p><i>Navicula globiceps</i> Lagerstedt, according to Cleve.</p>
+
+  <p>Willistown, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 24.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PINNATA PANT.
+  ?</span></p>
+
+  <p>Valve lanceolate, obtuse; axial area narrow, widened in the middle; striæ coarse, 7 in 10 µ in
+  the middle, radiate, 10 in 10 µ at the ends and transverse, indistinctly lineate. L. 40 µ.</p>
+
+  <p>Near <i>Navicula ardua</i> Mann (Diat. Albatross Voy., Cont. U. S. Nat. Herbarium Vol. 10, Part
+  5, p. 336, Pl. 53, Fig. 2) which, however, is said to have "strictly unbeaded costæ."</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 20.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PENNATA A. S.</span></p>
+
+  <p>Valve lanceolate, acute; axial area narrow; central area quadrate, transverse; striæ radiate,
+  coarse, 5 in 10 µ, lineate. L. 68-95 µ (Cleve).</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 22.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA INFLEXA GREG.</span></p>
+
+  <p>Valve slightly elliptical-lanceolate, sub-acute, smooth at the ends; axial area narrow, widened
+  in the middle; striæ radiate, 11 in 10 µ, lineate. Frustule in zone view constricted in the
+  middle. L. 28-45 µ.</p>
+
+  <p>Common along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Figs. 18 and 19.</p>
+
+  <div><span class="pagenum" id="page97">{97}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA OBLONGA
+  KUETZ.</span></p>
+
+  <p>Valve linear-lanceolate, with broad, rounded ends; margin sometimes undulate; axial area
+  narrow; central area large, orbicular; striæ in the middle distant, radiate, convergent at the
+  ends and curved or sharply bent, 7 in 10 µ, lineate. L. 70-200 µ (Cleve).</p>
+
+  <p>Blue clay. Occasional in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA HASTA PANT.</span></p>
+
+  <p>Valve lanceolate, gently tapering to the obtuse, produced ends; axial area lanceolate, widened
+  to an orbicular space in the middle; striæ radiate, the median coarse and quite distant, 5 in 10
+  µ, becoming closer at the ends where they are 12 in 10 µ, lineate. The distance between the median
+  striæ gives the appearance of a stauros.</p>
+
+  <p>Occasional in the blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA HASTA VAR. PUNCTATA N.
+  VAR.</span></p>
+
+  <p>Valve as in type but with striæ in the middle distinctly punctate and reaching the median
+  line.</p>
+
+  <p>Greenwich Point, Philadelphia.</p>
+
+  <p class="sp3">Pl. <a href="#plate27"><b>27</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA RHYNCOCEPHALA
+  KUETZ.</span></p>
+
+  <p>Valve lanceolate, with produced ends; axial area indistinct; central area small, rounded; striæ
+  radiate in the middle, convergent at the ends, 10-11 in 10 µ, punctate. L. 42 µ.</p>
+
+  <p>Fresh water. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA CRYPTOCEPHALA
+  KUETZ.</span></p>
+
+  <p>Valve lanceolate, with rostrate ends; axial area indistinct; central area small; striæ, 16 in
+  10 µ, lineate, radiate in the middle, convergent at the ends. L. 28 µ.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p>Intermediate forms occur between N. rhyncocephala and N. cryptocephala.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA LONGA (GREG.)
+  RALFS</span></p>
+
+  <p>Valve slender, rhombic, elongated, with acute ends; axial area indistinct; central area small;
+  striæ, 6 or 7 in 10 µ, radiate in the middle, elsewhere transverse; central pores closely
+  approximate. L. 120 µ.</p>
+
+  <p>New Rochelle, N. Y.</p>
+
+  <p>Pl. <a href="#plate31"><b>31</b></a>, Fig. 10.</p>
+
+  <p class="sp3">Cleve refers this form to N. directa var. remota Grun. Some specimens are found in
+  this locality showing the "generally twisted" median line mentioned by Gregory.</p>
+
+  <p class="ac"><span class="sc">Mesoleiæ Cl.</span></p>
+
+  <p class="sp3">Valve linear or elliptical; axial area narrow; central area quadrate; striæ
+  radiate, finely punctate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA MUTICA KUETZ.</span></p>
+
+  <p>Valve ovate, elliptical or lanceolate; axial area narrow; central area dilated into a stauros
+  not reaching the margin; striæ about 20 in 10 µ, more distant in the middle, radiate, punctate. A
+  punctum occurs on one side of the central nodule.</p>
+
+  <div><span class="pagenum" id="page98">{98}</span></div>
+
+  <p>Reported from New Jersey in fresh water. I have not found it. The figure is from a specimen
+  from another locality.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 6.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA MINIMA GRUN.</span></p>
+
+  <p>Valve broadly elliptical, 13-15 µ in length; axial area narrow; central area small but with a
+  quadrate pseudo-stauros which is striated; striæ, about 28 in 10 µ, radiate.</p>
+
+  <p>Agrees closely with N. saugeri var. Grun. in V. H. Synopsis, Pl. 14, Fig. 16, said to be
+  intermediate between N. minima and N. atomoides Grun. N. minima var. atomoides Grun. is
+  smaller.</p>
+
+  <p>Common in water-troughs.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PUPULA VAR.
+  BACILLARIOIDES GRUN.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area linear, expanding on both sides near the ends of
+  the valve, forming a transverse lunate space; central area small, apparently expanded into a
+  stauros, which, however, is striated; striæ, 18 in 10 µ, at the middle, closer at the ends,
+  punctate. L. 54 µ.</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 9.</p>
+
+  <p class="ac"><span class="sc">Bacillares Cl.</span></p>
+
+  <p class="sp3">Valve linear or linear-elliptical, with broad ends; axial area narrow, the median
+  line enclosed in siliceous ribs; striæ finely punctate, more distant in the middle.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA BACILLUM EHR.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area enclosed in siliceous ribs and slightly expanded on
+  each side at the ends; terminal nodules incrassate; central area small, elliptical; striæ, 15 in
+  10 µ in the middle, transverse, distinctly punctate, closer at the ends L. 47 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p>Pl. <a href="#plate26"><b>26</b></a>, Fig. 10.</p>
+
+  <p class="sp3">Cleve describes the form as having slightly radiate striæ in the middle. There is
+  considerable difference in the descriptions of Cleve, Donkin, Grunow and Van Heurck, as also in
+  all of the figures.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA AMERICANA
+  EHR.</span></p>
+
+  <p>Valve oblong-linear, with rounded ends, sometimes slightly constricted; axial area about
+  one-half the width of the valve, dilated in the middle; striæ parallel in the middle, radiate at
+  the ends, 15-16 in 10 µ. A punctum is usually found in the central nodule. L. 55-154 µ.</p>
+
+  <p>Blue clay. Occasional in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 8.</p>
+
+  <p class="ac"><span class="sc">Decipientes Cl.</span></p>
+
+  <p class="sp3">Valve lanceolate, with obtuse ends; axial area narrow; central area orbicular;
+  striæ radiate in the middle and more distant.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA SEMEN EHR.</span></p>
+
+  <p>Valve elliptic-lanceolate, with sub-rostrate, truncate apices; axial area narrow, <span
+  class="pagenum" id="page99">{99}</span>sinuous; central area orbicular; terminal fissures small,
+  hook-shaped; striæ robust, 7 or 8 in the middle, closer at the ends, indistinctly punctate or
+  lineolate.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p>Pl. <a href="#plate26"><b>26</b></a>, Fig. 11.</p>
+
+  <p class="sp3">Cleve states that this form belongs to the post-glacial deposits and is found
+  living only in the Hartz Mountains.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA INTEGRA WM.
+  SM.</span></p>
+
+  <p>Valve lanceolate with triundulate margins and rostrate-apiculate ends; striæ radiate, more
+  distant in the middle, 20-23 in µ, punctate; axial area very narrow, central area rounded or
+  elliptical. L. 33-43 µ.</p>
+
+  <p>Pavonia, N. J., artesian well. Common in Chester River, Md.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 5.</p>
+
+  <p class="ac"><span class="sc">Microstigmaticæ</span> <span class="smaller">CL.</span></p>
+
+  <p class="sp3">Valve lanceolate; axial area narrow; central area small, rounded; striæ finely
+  punctate, nearly parallel. (Includes here only the division Libellus.)</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA TUMIDA (BRÉB.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, with rounded ends; axial area narrow, central area elliptical; raphe slightly
+  sigmoid; striæ, 13 in 10 µ, finely punctate, a few shorter in the middle.</p>
+
+  <p><i>Scoliopleura tumida</i> (Bréb.) V. H.</p>
+
+  <p>Cape May, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate25"><b>25</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA GREVILLEI (AG.)
+  CL.</span></p>
+
+  <p>Frustules in gelatinous tubes, rectangular; zone with numerous longitudinal divisions. Valve
+  elliptical-lanceolate, obtuse; axial area narrow, central area small; striæ lineate, about 18 in
+  10 µ in the middle where they are slightly radiate and more evident, closer near the ends and
+  transverse; median line with terminal pores distant from the ends. L. 60 µ.</p>
+
+  <p><i>Schizonema grevillei</i> Ag.</p>
+
+  <p>East River, N. Y.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Figs. 3 and 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA LIBELLUS
+  GREG.</span></p>
+
+  <p>Valve rhombic-elliptical, obtuse at the ends; axial area narrow, central rounded, small; striæ
+  punctate, slightly radiate, about 19 in 10 µ; terminal fissures close to the ends, indistinct. L.
+  60 µ.</p>
+
+  <p>Cleve describes this form as having acute ends, while Gregory states that it is "more obtuse
+  and broader than N. rhombica." Gregory's Figure 101 apparently shows the ends acute, but he says
+  that the valve view is "rhombic or elliptic-lanceolate, broad, with obtuse ends" (Diat. of the
+  Clyde, p. 57, Pl. 6).</p>
+
+  <p>Hackensack Swamp, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 5.</p>
+
+  <p class="ac"><span class="sc">Orthostichæ Cl.</span></p>
+
+  <p class="sp3">Valve lanceolate or elongated; axial area narrow; central area sometimes apparently
+  dilated into a stauros; striæ punctate, the puncta in transverse and longitudinal rows.</p>
+
+  <div><span class="pagenum" id="page100">{100}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA CUSPIDATA
+  KUETZ.</span></p>
+
+  <p>Valve rhombic-lanceolate, with acute ends; axial area linear, narrow, not widened in the
+  middle; striæ transverse, 14-19 in 10 µ (Cl.). L. 70-150 µ.</p>
+
+  <p>Blue clay. Not uncommon in fresh water.</p>
+
+  <p>Pl. <a href="#plate26"><b>26</b></a>, Figs. 1 and 2.</p>
+
+  <p>Fig. 2 represents an inner valve or stratum, with strong costæ variable in size, formerly known
+  as Surirella craticula Ehr.</p>
+
+  <p><i>N. cuspidata var. ambigua (Ehr.) Cl.</i>&mdash;Valve elliptical-lanceolate, with rostrate
+  ends, smaller than the type and with finer striæ.</p>
+
+  <p>Crum Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA SPICULA (HICKIE)
+  CL.</span></p>
+
+  <p>Valve narrow, lanceolate with acute ends; axial area narrow, central area dilated into a
+  stauros reaching the margin; transverse striæ, 25-29 in 10 µ, longitudinal closer. L. 50-130
+  (Cl.).</p>
+
+  <p>Sometimes confused with N. crucigera.</p>
+
+  <p><i>Stauroneis spicula</i> Hickie.</p>
+
+  <p>Newark, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA CRUCIGERA (WM. SM.)
+  CL.</span></p>
+
+  <p>Valve lanceolate, narrow, with acute apices; central nodule a stauros reaching the margin but
+  crossed by two or three coarser striæ; transverse striæ, 12 in 10 µ, punctate, the puncta about 25
+  in 10 µ. L. 80-100 µ (Cl.). Frustules in gelatinous tubes or free.</p>
+
+  <p><i>Schizonema cruciger</i> Wm. Sm.</p>
+
+  <p>Pl. <a href="#plate26"><b>26</b></a>, Fig. 15.</p>
+
+  <p class="sp3">Reported as occurring in New York Bay, but I have not seen it. The figure is from a
+  specimen from another locality.</p>
+
+  <p class="ac"><span class="sc">Minusculæ Cl.</span></p>
+
+  <p class="sp3">Valve lanceolate or elliptical, chiefly distinguished by the small size; axial area
+  indistinct; central area small; striæ radiate, very finely punctate.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA ATOMUS NÆGELI</span></p>
+
+  <p>Valve elliptical, 6-8 µ in length; striæ radiate, 26-30 µ, closer near the ends; axial area
+  linear, scarcely widened in the middle.</p>
+
+  <p>Water-troughs and ditches. Probably common, but frequently not noticed because of its
+  minuteness. A mounting medium of the highest refractive index, such as realgar, is required to
+  resolve the striæ. In the figure the striæ are drawn a little coarser than they appear in most
+  specimens.</p>
+
+  <p class="sp3">Pl. <a href="#plate26"><b>26</b></a>, Fig. 12.</p>
+
+  <p class="ac"><span class="sc">Lævistriatæ Cl.</span></p>
+
+  <p class="sp3">Valve lanceolate, axial area distinct; central area orbicular; striæ coarse,
+  indistinctly punctate, approaching the costæ of Pinnularia.</p>
+
+  <div><span class="pagenum" id="page101">{101}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA YARRENSIS
+  GRUN.</span></p>
+
+  <p>Valve elliptical-lanceolate, with rounded ends; axial area lanceolate, widened in the middle;
+  striæ, 5 in 10 µ. L. 97 µ.</p>
+
+  <p>Cape May, N. J. Common.</p>
+
+  <p>Pl. <a href="#plate25"><b>25</b></a>, Fig. 14.</p>
+
+  <p>Fig. 15, a smaller form, 65 µ in length; striæ, 6 in 10 µ.</p>
+
+  <p class="sp3">Fig. 16, 54 µ in length; striæ, 8 in 10 µ (near var. valida Pant.).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA ELEGANS WM.
+  SM.</span></p>
+
+  <p>Valve elliptical-lanceolate, with produced ends; axial area very narrow, central area large,
+  orbicular; striæ strongly divergent in the middle, slightly, if at all, convergent at the ends,
+  curved toward the margin, indistinctly lineate, 9 in 10 µ. L. 95 µ.</p>
+
+  <p>Blue clay. Not rare.</p>
+
+  <p>Pl. <a href="#plate31"><b>31</b></a>, Fig. 1.</p>
+
+  <p><i>Navicula elegans var. cuspidata Cl.</i>&mdash;Valve as in type form but smaller and with
+  rostrate apices; striæ, 10 in 10 µ. L. 82 µ.</p>
+
+  <p>Belmar, N. J.</p>
+
+  <p>Pl. <a href="#plate31"><b>31</b></a>, Fig. 2.</p>
+
+  <p class="sp3">Cleve remarks that the type form is acute and the striæ 9, while the var. cuspidata
+  has 12 striæ in 10 µ. In Fig. 1, Pl. <a href="#plate31"><b>31</b></a>, is represented a valve
+  having 9 striæ in 10 µ, but not acute, while Fig. 2, with but slight variation in striæ, is more
+  cuspidate. It is probable there are intermediate variations.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NAVICULA PALPEBRALIS
+  BRÉB.</span></p>
+
+  <p>Valve elliptical-lanceolate, with acute apiculate ends; axial area broad, lanceolate; striæ
+  radiate, lineate, about 11 in 10 µ. L. 60 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p>Pl. <a href="#plate31"><b>31</b></a>, Figs. 6 and 7.</p>
+
+  <p>On Plate <a href="#plate40"><b>40</b></a>, Fig. 5, is represented an abnormal form of Navicula
+  in which the central pores are in a line transverse to the longitudinal axis and each raphe is
+  curved in a line which almost returns to the centre. The puncta are in curved lines radiating from
+  the rounded hyaline centre.</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p class="sp3">Weissflog has described valves of Navicula somewhat similar in punctation.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Pinnularia Ehr.</span> (1843)</h4>
+
+  <p class="ac">(pinnula, a small feather)</p>
+
+  <p>Valve linear or nearly so, with rounded ends; axial area broad; central and terminal areas
+  large; costæ smooth, transverse or radiating, usually convergent at the ends.</p>
+
+  <p>The costæ are channels on the inside of the valve, closed, except in the middle where
+  elliptical foramina, opening into the interior of the valve, give rise through their terminal
+  margins to the two longitudinal lines on each side of the valve. The raphe begins as a groove in
+  the side of the conical central nodule and continues as a cleft at right angles to the plane of
+  the surface of the valve, in which case the raphe forms a single line; if the raphe is inclined to
+  the valve surface, then two lines appear in projection, the upper and lower edges of the cleft. In
+  some forms the surface of the edge of the raphe on one side is folded or grooved for a
+  considerable distance, and the opposite edge is elevated into a ridge or <span class="pagenum"
+  id="page102">{102}</span>tongue fitting into the groove. In such cases it is possible, in
+  projection, to see the upper or outer edges of the raphe, the lower edges and the edges of the
+  tongue and groove, thus showing four lines; sometimes, when the tongue and groove do not meet, six
+  lines. The so-called inner channel is the part of the raphe on the inside of the tongue, and the
+  so-called exterior channel is the part of the raphe on the outside of the tongue. If, in addition
+  to this formation of the raphe, the plane of cleavage changes toward the terminal nodules, the
+  lines will cross each other and, when two are superimposed, disappear altogether. For the careful
+  examination of the raphe it is necessary to employ large forms, and it is advisable to use nitrate
+  of silver which remains in the raphe, and, as in slides mounted by Mr. F. J. Keeley, shows in a
+  beautiful manner the entire outline of raphe and fissures. The terminal fissures owe their
+  separation to the different directions taken by the two edges of the raphe on each side, one edge
+  bending in a wide curve toward the end of the valve, showing two lines, the upper and lower edges
+  of one side of the raphe when inclined to the plane of the surface, and the other edge of the
+  raphe turning suddenly in an opposite direction and ending abruptly in a curve, giving rise to the
+  appearance, by diffraction, of a punctum.</p>
+
+  <p>Pl. <a href="#plate40"><b>40</b></a>, Figs. 13, 14 and 15.</p>
+
+  <p>Endochrome consists of two chromatophores lying on the zones.</p>
+
+  <p>Pinnularia is usually divided into the Majores, or larger, and the Minores, or smaller forms,
+  the latter being further divided according to their striæ. The following classification is chiefly
+  that of Cleve.</p>
+
+  <p><i>Majores.</i>&mdash;Valve large, linear with parallel or slightly radiate striæ and broad
+  axial area.</p>
+
+  <p><i>Gracillimæ.</i>&mdash;Valve small, striæ parallel or nearly so; axial area very narrow.</p>
+
+  <p><i>Capitatæ.</i>&mdash;Valve with capitate or rostrate ends; striæ radiate.</p>
+
+  <p><i>Divergentes.</i>&mdash;Striæ strongly radiate.</p>
+
+  <p><i>Brevistriatæ.</i>&mdash;Striæ short.</p>
+
+  <p><i>Distantes.</i>&mdash;Striæ distant.</p>
+
+  <p><i>Tabellariæ.</i>&mdash;Striæ radiate in the middle, strongly convergent at the ends.</p>
+
+  <p class="sp3"><i>Marinæ.</i>&mdash;Marine forms.</p>
+
+  <p class="ac"><span class="sc">Majores</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MAJOR (KUETZ.) WM.
+  SM.</span></p>
+
+  <p>Valve linear, usually slightly gibbous in the middle and at the ends; raphe oblique; axial area
+  less than one-third the width of valve, convergent at the ends; striæ, 7 or 8 in 10 µ, radiate in
+  the middle, convergent at the ends, crossed by a narrow band. L. ? to 300 µ.</p>
+
+  <p>Blue clay. Fresh water. Abundant at Middletown, Delaware Co. (T. C. Palmer).</p>
+
+  <p>Pl. <a href="#plate28"><b>28</b></a>, Fig. 4.</p>
+
+  <p class="sp3">Fig. 9, Pl. <a href="#plate29"><b>29</b></a>, is one of a number of smaller forms
+  which are difficult to determine, approaching P. viridis.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MAJOR VAR. PULCHELLA
+  N. VAR.</span></p>
+
+  <p>Valve strongly gibbous in the middle and gradually widened to the rounded ends; axial area
+  broad, less than one-third the width of the valve, widened unilaterally in the middle; striæ, 7 in
+  10 µ, crossed by a band nearly as wide as the length of the costæ and scarcely distinct. L. 273
+  µ.</p>
+
+  <div><span class="pagenum" id="page103">{103}</span></div>
+
+  <p>The central nodule is scarcely evident, probably because it is not so thick as in other forms.
+  The outline is near to that of N. mesogongyla and certain forms of N. nobilis, differing from the
+  latter in the median line, striæ and band which is wider than that of P. latevittata var.
+  domingensis Cl.</p>
+
+  <p>Hammonton Pond, N. J.</p>
+
+  <p>Pl. <a href="#plate28"><b>28</b></a>, Fig. 2.</p>
+
+  <p class="sp3">A very beautiful form which I cannot find described or figured. It does not appear
+  to be N. major var. turgidula Cl., which has a narrow band. In the fossil deposit from Hopkinton,
+  N. H., valves occur similar in outline but smaller.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA NOBILIS
+  EHR.</span></p>
+
+  <p>Valve slightly gibbous in the middle and at the ends; median line complex; striæ, 4 or 5 in 10
+  µ, slightly convergent or parallel at the ends, crossed by a band one-third as wide as the length
+  of the striæ. L. ? to 350 µ.</p>
+
+  <p>Blue clay. Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate28"><b>28</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA DACTYLUS
+  EHR.</span></p>
+
+  <p>Valve broad, linear, slightly gibbous in the middle; ends broad, rounded; median line not
+  complex, sinuous; striæ, 4 or 5 in 10 µ, crossed by a very broad band. L. ? to 300 µ.</p>
+
+  <p><i>Navicula gigas</i> A. S.</p>
+
+  <p>Blue clay. Fresh water.</p>
+
+  <p>Pl. <a href="#plate28"><b>28</b></a>, Fig. 3.</p>
+
+  <p class="sp3">Forms occur which are with difficulty assigned to either nobilis or dactylus.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA DACTYLUS VAR. DARIANA
+  (A. S.) CL.</span></p>
+
+  <p>Valve linear-lanceolate, obtuse; axial area broad, less than one-third the width of the valve;
+  striæ, 6 in 10 µ, crossed by a broad band. L. 220 µ.</p>
+
+  <p>Absecon, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA DACTYLUS VAR. DEMERARÆ
+  CL.</span></p>
+
+  <p>Valve elliptical-lanceolate, with sub-cuneate ends; axial area lanceolate, broad in the middle;
+  median line flexuose; striæ radiate throughout, 6 in 10 µ. L. 150 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA GENTILIS (DONK.)
+  CL.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area about one-fourth the diameter of the valve; striæ
+  radiate in the middle, convergent at the ends, 7 in 10 µ, crossed by a broad indistinct band.</p>
+
+  <p>Fresh water. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA TRIGONOCEPHALA
+  CL.</span></p>
+
+  <p>Valve linear, gibbous in the middle and at the cuneate ends; axial area wider between the
+  middle and the ends, dilated to an elliptical space in the middle; striæ, 6 in 10 µ. L. 145 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 8.</p>
+
+  <div><span class="pagenum" id="page104">{104}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA VIRIDIS
+  NITZSCH</span></p>
+
+  <p>Valve linear-elliptical, with rounded ends; axial area narrow, widened in the middle; striæ, 6
+  to 7 in 10 µ, crossed by a band as wide as one-third the length of the striæ.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p>Pl. <a href="#plate29"><b>29</b></a>, Fig. 2.</p>
+
+  <p class="sp3">Quite variable in size. Approaches P. major by intermediate forms as in Fig. 9, Pl.
+  <a href="#plate29"><b>29</b></a>.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA VIRIDIS VAR. FALLAX
+  CL.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area narrow, slightly widened in the middle; striæ
+  sometimes unilaterally interrupted, nearly parallel, 10 in 10 µ.</p>
+
+  <p>Elm, N. J.</p>
+
+  <p>Pl. <a href="#plate29"><b>29</b></a>, Fig. 4.</p>
+
+  <p class="sp3">In Fig. 2, Pl. <a href="#plate30"><b>30</b></a>, a form is represented which
+  corresponds closely to Navicula viridis var. B, of Wm. Smith. It is given as synonymous with var.
+  fallax; it is bilaterally interrupted. Blue clay.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA VIRIDIS VAR.
+  ?</span></p>
+
+  <p>Valve linear-elliptical, with rounded ends; axial area narrow, widened in the middle to a
+  transverse fascia which is sometimes unilateral; striæ, 14, in the middle, divergent, convergent
+  at the ends and closer, crossed by a narrow band. L. 45-60 µ. Fascia sometimes absent or very
+  narrow.</p>
+
+  <p>Northbrook, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 17 (represents a form with wider area
+  than usual).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA VIRIDIS VAR. CAUDATA
+  N. VAR.</span></p>
+
+  <p>Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow, widened to an orbicular
+  space in the middle; striæ radiate in the middle, 11-12 in 10 µ, convergent and closer at the
+  ends, crossed by a narrow band; median line with very long terminal fissures; terminal nodules
+  noticeable because of the thickening of the edges of the terminal striæ. L. 43 µ.</p>
+
+  <p>Fresh water, Newtown Square. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA SOCIALIS
+  (PALMER)</span></p>
+
+  <p>Valve linear, with rounded ends; axial area broad, one-third the width of the valve; striæ
+  slightly radiate in the middle, convergent at the ends, elsewhere parallel, 8 in 10 µ, crossed by
+  an indistinct band about one-third the length of the striæ. L. 60-120 µ.</p>
+
+  <p>This species, discovered by Mr. Palmer near Media, Pa., is remarkable for the grouping of the
+  frustules "held with girdle sides together by a siliceous cementing of valve edges and enclosed in
+  a common coleoderm." The usual number included in a group is four, but sometimes six or eight are
+  noticed. The frustules adhere near their ends and are so firmly fastened that boiling in nitric
+  acid and bichromate of potash for fifteen minutes will not separate them.</p>
+
+  <p><i>Navicula socialis</i> Palmer (Proc. Acad. Nat. Sci., Phila., 1910, p. 460, Pl. 35).</p>
+
+  <p>Media, Pa.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 5.</p>
+
+  <div><span class="pagenum" id="page105">{105}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA ÆSTUARII
+  CL.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area broad, less than one-third the width of the valve;
+  central area a transverse fascia; striæ, 7 in 10 µ, parallel except at the ends where they are
+  slightly convergent; median line flexuose, with short, terminal semicircular fissures. L. 85
+  µ.</p>
+
+  <p>Port Penn, Delaware River. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 6.</p>
+
+  <p class="ac"><span class="sc">Gracillimæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MOLARIS (GRUN.)
+  CL.</span></p>
+
+  <p>Valve very convex, linear, with sub-cuneate ends; axial area narrow, expanded in the middle to
+  a transverse fascia reaching the margin; striæ divergent in the middle, convergent at the ends, 16
+  in 10 µ. L. 60 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA LEPTOSOMA
+  GRUN.</span></p>
+
+  <p>Valve linear, rounded at the ends; axial area narrow; central area a broad transverse fascia;
+  striæ slightly divergent in the middle and convergent at the ends, 17 in 10 µ in the middle,
+  closer at the ends. L. 56 µ.</p>
+
+  <p>Fresh water. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 10.</p>
+
+  <p class="ac"><span class="sc">Capitatæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MESOLEPTA
+  EHR.</span></p>
+
+  <p>Valve linear, with triundulate margins and capitate ends; axial area narrow, widened in the
+  middle; striæ divergent in the middle, convergent at the ends, about 12 in 10 µ. L. 34 µ.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MESOLEPTA VAR.
+  STAURONEIFORMIS GRUN.</span></p>
+
+  <p>Valve triundulate, capitate; axial area narrow, widened in the middle to a transverse fascia,
+  broader at the margin; striæ strongly divergent in the middle and convergent at the ends, 9-10 in
+  10 µ. L. 70 µ.</p>
+
+  <p>Pavonia, N. J., artesian well. Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 20.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA SUBCAPITATA
+  GREG.</span></p>
+
+  <p>Valve linear or linear-elliptical, with sub-capitate ends; axial area distinct, widened to a
+  transverse fascia in the middle; striæ divergent in the middle, convergent at the ends, 13 in 10
+  µ. L. 32 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 20.</p>
+
+  <div><span class="pagenum" id="page106">{106}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA SUBCAPITATA VAR.
+  PAUCISTRIATA GRUN.</span></p>
+
+  <p>Valve linear-elliptical, with rounded ends; axial area gradually widened into a broad,
+  transverse fascia; striæ divergent in the middle, convergent at the ends, 11-12 in 10 µ. L. 47
+  µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA TERMES (EHR.) A.
+  S.</span></p>
+
+  <p>Valve linear, with concave margins and rostrate-capitate ends; axial area narrow, widened in
+  the middle to an orbicular or sub-quadrate space; striæ divergent in the middle, scarcely, if at
+  all, convergent at the ends, 10 in 10 µ.</p>
+
+  <p>Pensauken, N. J., artesian well.</p>
+
+  <p>Pl. <a href="#plate29"><b>29</b></a>, Fig. 17.</p>
+
+  <p class="sp3">This is, I believe, the form figured by Schmidt (Atlas, Pl. 45, Fig. 67). Cleve
+  refers it to Pinnularia interrupta forma biceps, in which the central space is rhomboid.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA TERMES VAR.
+  STAURONEIFORMIS V. H.</span></p>
+
+  <p>Valve linear, with concave margins and capitate-rostrate ends; axial area narrow, widened into
+  a rhomboidal fascia, reaching the margin; striæ, 10 in 10 µ, divergent in the middle, convergent
+  at the ends.</p>
+
+  <p><i>Pinnularia interrupta forma stauroneiformis</i> Cl.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA APPENDICULATA (AG.)
+  CL.</span></p>
+
+  <p>Valve linear, with subcapitate ends; axial area narrow; central area a transverse fascia; striæ
+  divergent in the middle, convergent at the ends, 16 in 10 µ. L. 43 µ.</p>
+
+  <p>Fresh water. Marl pits, Lenola, N. J. (Palmer).</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA BRAUNII
+  GRUN.</span></p>
+
+  <p>Valve linear-lanceolate, with capitate ends; axial area gradually widened toward the middle and
+  expanded into a fascia reaching the margin; striæ divergent in the middle, convergent at the ends,
+  11 in 10 µ. L. 52 µ.</p>
+
+  <p>Pensauken, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MICROSTAURON (EHR.)
+  CL.</span></p>
+
+  <p>Valve convex, linear, tapering to sub-cuneate or sub-rostrate ends; axial area very narrow;
+  central area a broad fascia; striæ divergent in the middle, convergent at the ends, 12 in 10 µ. L.
+  35 µ.</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p>Pl. <a href="#plate29"><b>29</b></a>, Fig. 19.</p>
+
+  <p class="sp3">This form does not exactly correspond to Cleve's diagnosis, as the ends are not
+  broad. All species in the group Capitatæ are quite variable.</p>
+
+  <div><span class="pagenum" id="page107">{107}</span></div>
+
+  <p class="ac"><span class="sc">Divergentes</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA DIVERGENS VAR.
+  ELLIPTICA GRUN.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area widened in the middle to a transverse fascia;
+  striæ, 9 in 10 µ, divergent in the middle, convergent at the ends. L. 150 µ.</p>
+
+  <p>Fresh water. Not common in this locality.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA CARDINALICULUS
+  CL.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area wide, less than one-third the width of the valve,
+  expanded to a transverse fascia; striæ divergent in the middle and slightly convergent at the
+  ends, 9 in 10 µ. L. 97 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate30"><b>30</b></a>, Fig. 1.</p>
+
+  <p class="sp3">As a rule, the median fissures in Pinnularia are turned inwards on the side of the
+  longer edge of the terminal fissures, but not always. In this specimen the median fissures are
+  turned slightly toward the side of the shorter edge of the terminal fissures.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA LEGUMEN
+  EHR.</span></p>
+
+  <p>Valve linear, with more or less triundulate margins and broad, capitate ends; axial area less
+  than one-fourth the width of valve, widened in the middle; striæ strongly divergent in the middle
+  and convergent at the ends, 10 in 10 µ. L. 84 µ.</p>
+
+  <p>Fresh water. May's Landing, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA LEGUMEN VAR.
+  ?</span></p>
+
+  <p>Valve as in type, but with a transverse fascia; striæ, 10 in 10 µ, curved or bent near the
+  ends. L. 84 µ.</p>
+
+  <p>This form is not var. florentina Grun.</p>
+
+  <p>May's Landing, N. J. (with the type).</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA BRÉBISSONII (KUETZ.)
+  CL.</span></p>
+
+  <p>Valve linear-elliptical, with rounded ends; axial area narrow, widened into a transverse fascia
+  which is usually broader at the ends; striæ divergent in the middle, convergent at the ends, about
+  12 in 10 µ. L. 40-60 µ (Cl.).</p>
+
+  <p>Fresh water. Common.</p>
+
+  <p>Pl. <a href="#plate29"><b>29</b></a>, Fig. 12; Pl. <a href="#plate31"><b>31</b></a>, Fig.
+  11.</p>
+
+  <p class="sp3">Variable in outline.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MORMONORUM
+  (GRUN.)</span></p>
+
+  <p>Valve linear, with rounded ends; striæ divergent in the middle, convergent at the ends, 10 in
+  10 µ; axial area rhombic-lanceolate, widened to a fascia usually reaching the border. L. 62 µ.</p>
+
+  <p><i>Navicula mormonorum</i> Grun.</p>
+
+  <p>Common near Willistown, Pa.</p>
+
+  <p>This form is regarded by Cleve as P. brébissonii, but the axial area appears to distinguish it.
+  The valves are sometimes narrowed in the middle.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 11.</p>
+
+  <div><span class="pagenum" id="page108">{108}</span></div>
+
+  <p class="ac"><span class="sc">Brevistriatæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA ACROSPHÆRIA (BRÉB.)
+  CL.</span></p>
+
+  <p>Valve linear, gibbous in the middle and at the ends; axial area about half the width of the
+  valve; median line with approximate central pores; median area punctate; striæ nearly parallel,
+  radiate at the ends, 9 in 10 µ. L. 32-180 µ (Cl.).</p>
+
+  <p>Blue clay. Recent, fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA ACROSPHÆRIA VAR.
+  TURGIDULA GRUN. ?</span></p>
+
+  <p>Valve strongly gibbous in the middle; ends rounded; striæ, 12-13 in 10 µ. L. 54 µ.</p>
+
+  <p>Blue clay, Gloucester, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA BLANDITA N.
+  SP.</span></p>
+
+  <p>Valve linear, gibbous in the middle, and with rounded ends; striæ radiate in the middle,
+  convergent at the ends, 13 in 10 µ; axial area about one-fourth the width of the valve, widened in
+  the middle; median line with small semicircular terminal fissures. L. 65 µ.</p>
+
+  <p>Pavonia, N. J., artesian well. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 25.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA PARVA (EHR.) CL. VAR.
+  ?</span></p>
+
+  <p>Valve linear, tapering to the subcapitate ends; axial area broad, lanceolate; median line with
+  approximate central pores and semicircular terminal fissures; striæ slightly divergent in the
+  middle and convergent at the ends, 12 in 10 µ. L. 58 µ.</p>
+
+  <p>Differs from the type in having finer striæ.</p>
+
+  <p>Atco, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA NODOSA FORMA CAPITATA
+  CL.</span></p>
+
+  <p>Valve triundulate, with capitate ends; axial area about one-fourth the width of valve; striæ
+  parallel, convergent at the ends, 10 in 10 µ, sometimes interrupted in the middle. L. 47 µ.</p>
+
+  <p>Fresh water. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Figs. 15 and 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA POLYONCA (BRÉB.)
+  LEWIS</span></p>
+
+  <p>Valve with triundulate margins, more inflated in the middle, with capitate ends; axial area
+  very broad; striæ marginal, short, 9 in 10 µ, divergent in the middle, convergent at the ends. L.
+  97 µ.</p>
+
+  <p>Kirkwood Pond, N. J.</p>
+
+  <p>Pl. <a href="#plate30"><b>30</b></a>, Fig. 21.</p>
+
+  <p class="sp3">The description of Kuetzing (Species Algarum, p. 85), where he states that the
+  margins are "triundulate, the median inflation larger, apices rounded-capitate," appears to
+  sufficiently distinguish this species, which I believe to be the same as Brun's Navicula
+  peripunctata, except that the form figured (Espèces Nouvelles, Pl. 16, Fig. 11) is interrupted in
+  the middle, a common variation in these forms. Cleve makes Navicula polyonca Bréb. equal
+  Pinnularia mesolepta, but at the same time he considers Lewis' form and also Brun's as equivalent
+  to Navicula formica Ehr., and calls it Pinnularia nodosa var. formica Ehr. P. mesolepta has a
+  narrower area than nodosa. I adhere to Lewis' identification, as in any case it is the form here
+  figured and is nearly, if not quite, the same as Brun's species.</p>
+
+  <div><span class="pagenum" id="page109">{109}</span></div>
+
+  <p class="ac"><span class="sc">Distantes</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA LATA (BRÉB.) WM.
+  SM.</span></p>
+
+  <p>Valve linear-elliptical, broad; axial area broad, widened in the middle; striæ slightly radiate
+  in the middle, 3 in 10 µ; median line oblique, the terminal fissures hook-shaped. L. 86 µ.</p>
+
+  <p>Blue clay. Not uncommon.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA BOREALIS
+  EHR.</span></p>
+
+  <p>Valve linear, with rounded or sub-truncate ends; axial area about one-fourth the width of the
+  valve, widened in the middle; median line with large hook-shaped terminal fissures; striæ, 4 or 5
+  in 10 µ. L. 54 µ.</p>
+
+  <p>Blue clay. Occasional in fresh water in a smaller form. Specimens occur intermediate between P.
+  lata and P. borealis.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 22; Pl. <a
+  href="#plate31"><b>31</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA BOREALIS VAR. SCALARIS
+  (EHR.) CL.</span></p>
+
+  <p>Valve narrow, linear; axial area broad, widened into a transverse fascia; striæ, 8 in 10 µ. L.
+  32 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 24.</p>
+
+  <p class="ac"><span class="sc">Tabellariæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA STOMATOPHORA (GRUN.)
+  CL.</span></p>
+
+  <p>Valve linear, with rounded ends; axial area less than one-third the width of the valve,
+  gradually widened in the middle to a transverse fascia; on each side of the central nodule is a
+  lunate space; striæ divergent in the middle, convergent at the ends, 13 in 10 µ; terminal fissures
+  very long, bayonet shaped. L. 75 µ.</p>
+
+  <p>Cleve describes a variety continua as not interrupted. In some forms the fascia is marked by
+  very faint, short striæ on the margin.</p>
+
+  <p>Fresh water. Newtown Square.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 12.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA GIBBA (KUETZ.) V.
+  H.</span></p>
+
+  <p>Valve linear, tapering to the subcapitate ends; axial area dilated in the middle; striæ, 10-11
+  µ, divergent in the middle, convergent at the ends. L. 80 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA MESOGONGYLA (EHR.)
+  CL.</span></p>
+
+  <p>Valve linear, gibbous in the middle, ends subcapitate; axial area narrow, widened in the middle
+  to a large orbicular space; striæ strongly divergent in the middle, convergent at the ends, 11 in
+  10 µ. L. 60 µ.</p>
+
+  <p>Fresh water. Common.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 6.</p>
+
+  <div><span class="pagenum" id="page110">{110}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA STAUROPTERA (GRUN.)
+  CL.</span></p>
+
+  <p>Valve linear, with slightly triundulate margins tapering to the subcapitate ends; axial area
+  more than one-third the width of the valve, slightly widened in the middle; median line with
+  approximate central pores and semicircular terminal fissures; striæ divergent in the middle,
+  convergent at the ends, 11 in 10 µ. L. 82 µ.</p>
+
+  <p>May's Landing, N. J.</p>
+
+  <p>Pl. <a href="#plate30"><b>30</b></a>, Fig. 13.</p>
+
+  <p class="sp3">Some of the forms are more triundulate than the specimen figured.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA STAUROPTERA VAR.
+  INTERRUPTA CL.</span></p>
+
+  <p>Valve linear, tapering to the subcapitate ends; axial area broad, widened in the middle to a
+  transverse fascia; striæ divergent in the middle, convergent at the ends, 10 in 10 µ; median pores
+  approximate. L. 118 µ.</p>
+
+  <p>Schuylkill River.</p>
+
+  <p class="sp3">Pl. <a href="#plate30"><b>30</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA TABELLARIA (EHR.)
+  CL.</span></p>
+
+  <p>Valve linear, gibbous in the middle and tapering to the subcapitate ends; axial area about
+  one-third the width of the valve, widened in the middle; median line with approximate central
+  pores and bayonet-shaped terminal fissures; striæ sometimes unilaterally interrupted, divergent in
+  the middle, strongly convergent at the ends, 9 in 10 µ. L. 138 µ.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Pl. <a href="#plate30"><b>30</b></a>, Fig. 9.</p>
+
+  <p>The form here figured has coarser striæ than in the type which is also usually more
+  capitate.</p>
+
+  <p class="sp3">P. legumen has triundulate margins, P. mesogongyla has an orbicular space, while P.
+  gibba has the space widened. According to Cleve, P. gibba has approximate central pores, as has
+  also P. mesogongyla. In what I have considered to be P. legumen, the central pores are more
+  approximate than in the other two species mentioned. In fact, all of the three resemble each other
+  closely, and are variously named by different authors. The form of P. gibba here figured, which
+  may be P. stauroptera, is not the typical form of Wm. Smith, which has a narrow area and central
+  space. There are, however, among the typical specimens in H. L. Smith's Type Slide No. 275,
+  smaller valves which show a resemblance.</p>
+
+  <p class="ac"><span class="sc">Marinæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PINNULARIA RECTANGULATA (GREG.)
+  CL.</span></p>
+
+  <p>Valve linear, with abruptly rounded ends; axial area very narrow; central area large, somewhat
+  quadrate; striæ, 7-8 in 10 µ. L. 78 µ.</p>
+
+  <p><i>Navicula rectangulata Greg.</i></p>
+
+  <p>Shark River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate29"><b>29</b></a>, Fig. 7.</p>
+
+  <div><span class="pagenum" id="page111">{111}</span></div>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Epithemia</span> <span
+  class="smaller">BRÉB.</span> (1838)</h4>
+
+  <p class="ac">(epithema, a cover or lid)</p>
+
+  <p>Frustules epiphytic, solitary, sometimes geminate, adherent on the ventral side at the ends; in
+  zone view rectangular, sometimes tumid in the middle. Valve arcuate, having an interior costate
+  stratum or transverse septa extending to the girdle, often detached, and an exterior valve surface
+  with transverse rows of puncta. Central and terminal nodules not easily seen; in some species a
+  true raphe is indicated.</p>
+
+  <p>The resemblance between Epithemia and Eunotia has been already mentioned. In the shape and
+  striation of the valves there is an approach to Cymbella.</p>
+
+  <p>The genus is divided into two groups, one in which the costæ alternate with double rows of
+  puncta, as in E. turgida, and the other in which the rows of puncta are more than two.</p>
+
+  <p class="sp3">The endochrome usually consists of a band lying along the ventral zone and
+  extending in two flaps on the valves.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA TURGIDA (EHR.)
+  KUETZ.</span></p>
+
+  <p>Valve arcuate, with ends subcapitate; costæ radiate, 4 in 10 µ, alternating with double rows of
+  puncta. Median nodule central, the raphe curved toward the ventral edge which it closely
+  follows.</p>
+
+  <p>Parasitic on algæ. Very common in fresh water, especially in ponds. In the figure the valve is
+  asymmetrical with respect to the transverse axis, an unusual condition.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA ARGUS KUETZ.</span></p>
+
+  <p>Valve with dorsal margin convex, and ventral margin nearly straight; ends rounded, constricted;
+  costæ robust, alternating with more than two rows of puncta; zone view rectangular, the thickened
+  ends of the costæ forming large nodules in a row along the edge of the valve next to the
+  connecting zone.</p>
+
+  <p><i>Cystopleura argus</i> (Ehr.) Kunze.</p>
+
+  <p>Common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Figs. 15 and 21.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA ARGUS VAR. ?</span></p>
+
+  <p>Valve strongly arcuate on the dorsal side and concave on the ventral; tapering to the rounded
+  but not produced ends; costæ at unequal distances, about 2 in 10 µ; granules in transverse rows, 8
+  in 10 µ. L. 100 µ.</p>
+
+  <p>Pensauken, N. J., artesian well.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA MUELLERI A. S.
+  ?</span></p>
+
+  <p>Valve broad, convex, slightly arcuate, with obtuse, somewhat constricted apices; costæ about 4
+  in 10 µ; striæ, 12-14 in 10 µ; in zone view the outline is rectangular, slightly tumid in the
+  middle. L. 78 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 17.</p>
+
+  <div><span class="pagenum" id="page112">{112}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA ZEBRA VAR. PROBOSCIDEA
+  (KUETZ.) GRUN.</span></p>
+
+  <p>Valve convex on the dorsal, concave on the ventral side; costæ, 3-4 in 10 µ, slightly
+  radiating; apices recurved, capitate.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 18.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA GIBBERULA VAR. PRODUCTA
+  GRUN.</span></p>
+
+  <p>Valve narrow, lunate, with produced and arcuate apices; costæ radiate, 3-4 in 10 µ; striæ,
+  16-18 in 10 µ, punctate. L. 58 µ, usually smaller.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA MUSCULUS
+  KUETZ.</span></p>
+
+  <p>Valve short, strongly arcuate on the dorsal, concave on the ventral side; apices slightly
+  produced; costæ radiate, about 5 in 10 µ; striæ, 15 in 10 µ, punctate. L. 20-60 µ.</p>
+
+  <p>Shark River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 20.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">EPITHEMIA MUSCULUS VAR.
+  CONSTRICTA (BRÉB.) V. H.</span></p>
+
+  <p>Frustule elliptical, slightly constricted in the middle. Valve convex on the dorsal, straight
+  on the ventral side; costæ about 4 in 10 µ; striæ about 18 in 10 µ, finely punctate. L. 45 µ.</p>
+
+  <p><i>Epithemia succinta</i> Bréb.</p>
+
+  <p>New Rochelle, N. Y.</p>
+
+  <p class="sp3">Pl. <a href="#plate31"><b>31</b></a>, Fig. 22.</p>
+
+  <h4 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Rhopalodia</span> <span
+  class="smaller">MUELLER</span> (1885)</h4>
+
+  <p class="ac">(Rhopalodes, like a war club)</p>
+
+  <p>Frustule in zone view linear, linear-elliptical (in our species), or clavate. Valve reniform or
+  lunate; a raphe, not visible in some species in the usual position of the valve, is found along
+  the convex edge or keel. Median and terminal nodules, although very small, can be determined. The
+  name is more appropriate to the African species which are clavate. Two species only are found in
+  this locality.</p>
+
+  <p>The chief distinction between Epithemia and Rhopalodia is in the position of the raphe and the
+  nodules. In R. gibba and R. ventricosa the costæ are parallel and not radiate since the valves are
+  not lunate.</p>
+
+  <p class="sp3">Chromatophore a single band irregularly divided.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHOPALODIA GIBBA (KUETZ.)
+  MUELLER</span></p>
+
+  <p>Valve linear, arcuate on the dorsal, straight on the ventral side, reflexed at the extremities.
+  Costæ, 6-7 in 10 µ; striæ about 14 in 10 µ. L. 80-200 µ.</p>
+
+  <p>Fresh water. Common.</p>
+
+  <p>Pl. <a href="#plate31"><b>31</b></a>, Fig. 23.</p>
+
+  <p class="sp3">In this species the raphe and nodules can be seen only when the valve is examined
+  at right angles to its usual position.</p>
+
+  <div><span class="pagenum" id="page113">{113}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">RHOPALODIA VENTRICOSA (KUETZ.)
+  MUELLER</span></p>
+
+  <p>Valve gibbous in the middle on the dorsal side, straight on the ventral side, with reflexed
+  apices; costæ, 7 in 10 µ; striæ, 14-16 in 10 µ. L. 40-100 µ.</p>
+
+  <p>The median nodule appears as a minute depression in the middle of the dorsal side. The two
+  species usually occur together.</p>
+
+  <p><i>Epithemia gibba</i> var. <i>ventricosa</i> Kuetz.</p>
+
+  <p class="sp4">Pl. <a href="#plate31"><b>31</b></a>, Fig. 24.</p>
+
+  <h2>SURIRELLOIDEÆ</h2>
+
+  <p>The Surirelloideæ are usually understood to include the genera Surirella, Podocystis,
+  Cymatopleura and Campylodiscus, all of which resemble each other more or less, either in having a
+  keel or markings like the divisions of the keel in Surirella and a median line, or pseudoraphe.
+  The genus Nitzschia also has a keel, but it does not border each side of the valve as in
+  Surirella, being found either near one margin or between it and the centre. Certain of the
+  Surirellæ are allied to the group Tryblionella of the Nitzschiæ, while forms of Stenopterobia are
+  distinguished with difficulty from the group Sigmata.</p>
+
+  <p>The following arrangement, therefore, is intended to include all genera having a keel or
+  something which resembles it.</p>
+
+  <p><i>Hantzschia.</i>&mdash;Valve asymmetrical; keels of the two valves opposite each other.</p>
+
+  <p><i>Nitzschia.</i>&mdash;Valve asymmetrical; keels not (usually) opposite each other.</p>
+
+  <p><i>Surirella.</i>&mdash;Valve usually symmetrical; a keel on each border.</p>
+
+  <p><i>Cymatopleura.</i>&mdash;Valve without an elevated keel, but with markings like those of
+  Surirella; undulated in zone view.</p>
+
+  <p class="sp3"><i>Campylodiscus.</i>&mdash;Valves saddle-shaped.</p>
+
+  <h3 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Hantzschia</span> <span
+  class="smaller">GRUN.</span> (1877)</h3>
+
+  <p class="ac">(named after C. A. Hantzsch)</p>
+
+  <p>Valve arcuate, with rostrate ends; keel puncta short, prolonged into costæ or extending across
+  the valve; median nodule rudimentary; the keels of the two valves opposite each other.</p>
+
+  <p>Distinguished from Nitzschia chiefly by the position of the keels. According to Mereschkowsky,
+  however, two species of Nitzschia, N. lanceolata and N. spectabilis, show the same
+  peculiarity.</p>
+
+  <p class="sp3">Chromatophores four, two on each of the zones (Mereschkowsky).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HANTZSCHIA AMPHIOXYS (EHR.)
+  GRUN.</span></p>
+
+  <p>Valve slightly arcuate, with rostrate apices; keel puncta, 8 in 10 µ; striæ transverse, 16-18
+  in 10 µ, punctate. L. 60 µ.</p>
+
+  <p>Quite variable.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 9.</p>
+
+  <div><span class="pagenum" id="page114">{114}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HANTZSCHIA AMPHIOXYS VAR. MAJOR
+  GRUN.</span></p>
+
+  <p>Valve as in type, but the keel puncta are 5 in 10 µ and the striæ are 11-12 in 10 µ. L. 71
+  µ.</p>
+
+  <p>H. amphioxys var. major Grun. is stated to be 120 µ in length. The present form is smaller but
+  corresponds in puncta and striation. Van Heurck remarks that it approaches H. virgata.</p>
+
+  <p>Abundant in sand ripples on the beach at Cape May, N. J.</p>
+
+  <p>Pl. <a href="#plate39"><b>39</b></a>, Fig. 4.</p>
+
+  <p>Fig. 6, Pl. <a href="#plate39"><b>39</b></a>, is drawn from an authentic specimen of Wm.
+  Smith's Nitzschia amphioxys, from England, and is introduced for comparison. The central nodule is
+  not evident.</p>
+
+  <p class="sp3">Fig. 3, Pl. <a href="#plate39"><b>39</b></a>, is from a specimen from an unknown
+  locality. The keel puncta are 6 and the striæ 16 in 10 µ.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HANTZSCHIA VIRGATA (ROPER)
+  GRUN.</span></p>
+
+  <p>Valve arcuate on the dorsal side, nearly straight on the ventral side, with rostrate, recurved
+  apices; keel puncta prolonged to one-third the width of the valve, 4 in 10 µ; transverse striæ,
+  9-10 in 10 µ. L. 115 µ.</p>
+
+  <p>Shark River, N. J. (Kain).</p>
+
+  <p>I have not been able to find this form on our coast. The figure is drawn from a specimen from
+  another locality.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 23.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HANTZSCHIA MARINA (DONK.)
+  GRUN.</span></p>
+
+  <p>Valve with dorsal margin slightly arcuate, ventral margin straight; apices rostrate and
+  recurved; keel puncta, 6 in 10 µ, prolonged into costæ across the entire valve; transverse striæ,
+  12 in 10 µ, in double rows of alternating puncta between the costæ. L. 106 µ.</p>
+
+  <p><i>Epithemia marina</i> Donkin.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 22.</p>
+
+  <h3 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Nitzschia</span> <span
+  class="smaller">HASSALL</span> (1845), em. <span class="smaller">GRUN.</span> (1880)</h3>
+
+  <p class="ac">(named after Christian L. Nitzsch, of Halle)</p>
+
+  <p>Frustules usually free, sometimes enclosed in tubes or united into a filament. Valves keeled,
+  the keels of the two valves usually diagonally opposite (see Hantzschia); keel puncta short or
+  prolonged.</p>
+
+  <p>According to Mereschkowsky, there are at least two endochrome plates placed transversely on the
+  zones; sometimes there are from four to six plates, in one species twenty granules and in another
+  no trace of any endochrome whatever.</p>
+
+  <p class="sp3">The following analysis is that of Grunow as given in Cleve and Grunow's "Arctic
+  Diatoms," and adopted and illustrated by Van Heurck in his "Synopsis."</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">GROUPS</span></p>
+
+  <p>1. <i>Tryblionella.</i>&mdash;Keel very excentric, valve often folded; keel puncta indistinct,
+  usually the same in number as the striæ.</p>
+
+  <p>2. <i>Panduriformes.</i>&mdash;Valve broad, constricted in the middle, with more or less
+  evident fold; keel very near the edge; keel puncta quite evident or apparently wanting.</p>
+
+  <div><span class="pagenum" id="page115">{115}</span></div>
+
+  <p>3. <i>Apiculatæ.</i>&mdash;Keel very near the edge; valve linear or somewhat narrower in the
+  middle; striæ on the longitudinal fold fainter than on the remaining surface, or wanting; puncta
+  not in quincunx.</p>
+
+  <p>4. <i>Pseudo-Tryblionella.</i>&mdash;Keel more or less close to the edge; valve with a more or
+  less deep longitudinal fold over which the striæ are spread in the same way as over the remaining
+  surface; keel puncta always distinct.</p>
+
+  <p>5. <i>Circumsutæ.</i>&mdash;Valve with more or less wide longitudinal fold; keel very
+  excentric; keel puncta quite evident; surface of valve irregularly punctate and also traversed by
+  rows of delicate puncta which belong to a different layer of the valve.</p>
+
+  <p>6. <i>Dubiæ.</i>&mdash;Like the group Pseudo-Tryblionella, but the valves are not so much
+  folded; frustules sometimes narrowed in the middle. The separation of species is difficult and, in
+  part, doubtful. Keel excentric.</p>
+
+  <p>7. <i>Bilobatæ.</i>&mdash;Like the group Dubiæ, but with more central keel and so forming a
+  transition to the group Pseudo-Amphiprora; valves without longitudinal folds.</p>
+
+  <p>8. <i>Pseudo-Amphiprora.</i>&mdash;Valve with quite central, sharp keel, arcuate, without
+  longitudinal fold; keel puncta always evident; frustule narrowed in the middle with more or less
+  marked central nodule.</p>
+
+  <p>Includes two species not found in this locality.</p>
+
+  <p>9. <i>Perrya.</i>&mdash;Valve arched with very sharp central keel; not narrowed in the middle;
+  keel puncta mostly on short or long lines which are sometimes interrupted.</p>
+
+  <p>Includes six species not found in this locality.</p>
+
+  <p>10. <i>Epithemioideæ.</i>&mdash;Keel excentric; keel puncta extended into costæ across the
+  entire valve.</p>
+
+  <p>11. <i>Grunowia.</i>&mdash;As in the group Epithemioideæ, except that the costæ are shorter,
+  not extending across the valve; keel very excentric.</p>
+
+  <p>12. <i>Scalares.</i>&mdash;Like Grunowia, but with sharper, somewhat excentric keel; transverse
+  section of frustule quadrangular.</p>
+
+  <p>13. <i>Insignes.</i>&mdash;Like Scalares, but with more central keel so that many of the forms
+  are near the group Perrya; frustule somewhat sigmoid.</p>
+
+  <p>14. <i>Bacillaria.</i>&mdash;Keel central or nearly so; valve somewhat arched; keel sharp, as
+  in the group Insignes.</p>
+
+  <p>15. <i>Vivaces.</i>&mdash;Keel moderately excentric; valve, according to position,
+  semi-lanceolate, with keel puncta in short rows, or lanceolate with quite central keel. The valves
+  have in many positions a resemblance to Hantzschia, so that N. vivax frequently becomes confounded
+  with a form of H. amphioxys. The median keel puncta are not distant and a central nodule is not
+  evident as is the case in all species of Hantzschia.</p>
+
+  <p>16. <i>Spathulatæ.</i>&mdash;Like the group Bacillaria, but usually with very delicate striated
+  valves; keel in valve view usually bordered with two parallel lines.</p>
+
+  <p>17. <i>Dissipatæ.</i>&mdash;Like Vivaces and Spathulatæ, but with smaller central keel and
+  without parallel lines. Valves usually small, very delicately striated; no central nodule.</p>
+
+  <p>18. <i>Sigmoideæ.</i>&mdash;Keel quite central; no parallel lines; frustule sigmoid; valve
+  without longitudinal furrow; keel puncta not extended; no central nodule evident.</p>
+
+  <p>19. <i>Sigmata.</i>&mdash;Like Sigmoideæ, but with a more excentric keel.</p>
+
+  <p>20. <i>Obtusæ.</i>&mdash;Like Sigmata, with a more or less excentric keel which has in the
+  middle a small bending to the inside; middle keel puncta somewhat more distant than the others,
+  and between them a central nodule evident.</p>
+
+  <div><span class="pagenum" id="page116">{116}</span></div>
+
+  <p>21. <i>Spectabiles.</i>&mdash;Valve large, slightly arcuate, with excentric keel; no
+  longitudinal folds; keel puncta somewhat extended over the valve but much less than in the group
+  Insignes, and often scarcely perceptible.</p>
+
+  <p>22. <i>Lineares.</i>&mdash;Keel somewhat excentric, but less than in Spectabiles; frustule
+  straight, sometimes a little constricted in the middle, so that a transition is shown to the
+  groups Dubiæ and Bilobatæ. Valve without longitudinal fold; keel puncta round or somewhat angular,
+  scarcely extended.</p>
+
+  <p>23. <i>Lanceolatæ.</i>&mdash;Valve lanceolate, linear-lanceolate or rarely elliptical, with
+  very excentric keel; not folded; keel puncta not extended.</p>
+
+  <p class="sp3">24. <i>Nitzschiella.</i>&mdash;Valve with excentric keel and long, produced
+  apices.</p>
+
+  <p class="ac"><span class="sc">Tryblionella</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA TRYBLIONELLA
+  HANTZSCH</span></p>
+
+  <p>Valve elliptical-lanceolate, with subacute apices; longitudinal fold well marked; striæ coarse,
+  transverse, 5 in 10 µ; indistinct puncta intermediate between the striæ. L. 45 µ. Quite
+  variable.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA GRANULATA
+  GRUN.</span></p>
+
+  <p>Valve elliptical or elliptical-lanceolate; striæ in double rows, each row of three or four
+  small puncta along the margin and rows of large puncta about 6 in 10 µ across the valve. L. 28-44
+  µ.</p>
+
+  <p>Blue clay. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 3.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA NAVICULARIS (BRÉB.)
+  GRUN.</span></p>
+
+  <p>Valve elliptical-lanceolate, with acute apices; striæ on one side a double row of large and
+  small puncta, and on the other side radiate short rows of large puncta, 7 in 10 µ; middle of valve
+  hyaline. L. 35-60 µ.</p>
+
+  <p>Blue clay. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA COMPRESSA
+  (BAIL.)</span></p>
+
+  <p>Valve elliptical-lanceolate, sometimes acuminate; striæ, 6 or 7 in 10 µ, coarsely punctate. L.
+  56 µ.</p>
+
+  <p><i>Pyxidicula compressa</i> Bailey.</p>
+
+  <p><i>Nitzschia punctata</i> (Wm. Sm.) Grun.</p>
+
+  <p><i>Tryblionella punctata</i> Wm. Sm.</p>
+
+  <p>Common along the coast.</p>
+
+  <p>Pl. <a href="#plate39"><b>39</b></a>, Fig. 7.</p>
+
+  <p>Var. minor (H. L. Smith).&mdash;Valve acuminate; striæ, 8 in 10 µ. L. 22 µ.</p>
+
+  <p><i>Pyxidicula compressa</i> var. <i>minor</i> H. L. Smith, Type Slide No. 431.</p>
+
+  <p>Pl. <a href="#plate39"><b>39</b></a>, Fig. 8.</p>
+
+  <p class="sp3">The smaller forms occur northward, while the larger are found southward. This is
+  unquestionably Bailey's form, as indicated by his figure and by the fact that it is found
+  everywhere along the coast. Wm. Smith's T. punctata is the same species, although the puncta are
+  smaller.</p>
+
+  <div><span class="pagenum" id="page117">{117}</span></div>
+
+  <p class="ac"><span class="sc">Panduriformes</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA PANDURIFORMIS
+  GREG.</span></p>
+
+  <p>Valve elliptical, constricted in the middle, with sub-cuneate apices; longitudinal fold, with a
+  punctate longitudinal line; striæ transverse and oblique, 15 in 10 µ; keel puncta, 6 in 10 µ. L.
+  108 µ.</p>
+
+  <p>Along the coast. More often found southward.</p>
+
+  <p class="sp3">Pl. <a href="#plate39"><b>39</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA PANDURIFORMIS VAR.
+  MINOR GRUN.</span></p>
+
+  <p>Valve elliptical, constricted in the middle, with cuneate apices; keel puncta, 9 in 10 µ; striæ
+  in transverse and oblique lines about 20 in 10 µ; longitudinal fold bordered by a punctate line.
+  L. 34 µ.</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p>Pl. <a href="#plate32"><b>32</b></a>, Fig. 5.</p>
+
+  <p class="sp3">The var. continua Grun. is reported as occurring in Shark River. It varies in
+  having the longitudinal fold punctate. It is also usually smaller than var. minor.</p>
+
+  <p class="ac"><span class="sc">Apiculatæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA APICULATA (GREG.)
+  GRUN.</span></p>
+
+  <p>Valve oblong-linear, with cuneate-apiculate apices; striæ punctate, apparently interrupted or
+  pervious, about 18 in 10 µ. L. 26 µ.</p>
+
+  <p>Chester River, Md.</p>
+
+  <p>Pl. <a href="#plate32"><b>32</b></a>, Fig. 6.</p>
+
+  <p class="sp3">The puncta are continued across the valve, but are less distinct on the fold. The
+  figure shows the entire frustule with the fold on each valve. The valves are sometimes slightly
+  constricted.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA ACUMINATA (WM. SM.)
+  GRUN.</span></p>
+
+  <p>Valve linear, sometimes slightly constricted in the middle, with acuminate apices; longitudinal
+  fold entirely without or with indistinct striæ; keel puncta not evident; striæ, 14-15 in 10 µ. L.
+  82 µ.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA PLANA WM.
+  SM.</span></p>
+
+  <p>Valve linear; apices acute, slightly constricted in the middle; longitudinal fold further from
+  the keel than the margin, broad, with scattered puncta; striæ subtle, irregular, interrupted,
+  about 18 in 10 µ; keel puncta oblong, 3-6 in 10 µ. L. 100-170 µ.</p>
+
+  <p>Blue clay. Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 2.</p>
+
+  <div><span class="pagenum" id="page118">{118}</span></div>
+
+  <p class="ac"><span class="sc">Pseudo-Tryblionella</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA LITORALIS VAR.
+  DELAWARENSIS GRUN.</span></p>
+
+  <p>Valve linear, with obtusely rounded cuneate ends, scarcely, if at all, constricted in the
+  middle; longitudinal fold wide; keel puncta, 5 or 6 in 10 µ, sometimes confluent; striæ obscure,
+  about 21 in 10 µ. L. 75 µ.</p>
+
+  <p>Delaware River.</p>
+
+  <p>Pl. <a href="#plate32"><b>32</b></a>, Fig. 12.</p>
+
+  <p class="sp3">This form is drawn from a slide of Christian Febiger containing an abundance of
+  specimens from Delaware City, and marked "Nitzschia dubia."</p>
+
+  <p class="ac"><span class="sc">Circumsutæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA CIRCUMSUTA (BAIL.)
+  GRUN.</span></p>
+
+  <p>Valve elliptical, sometimes more than 200 µ in length; longitudinal fold more or less
+  conspicuous; keel puncta about 4 in 10 µ, the middle distant with the appearance of a nodule;
+  striæ irregular, subtle, finely punctate, frequently interrupted.</p>
+
+  <p><i>Surirella circumsuta</i> Bail.</p>
+
+  <p><i>Tryblionella scutellum</i> Wm. Sm.</p>
+
+  <p>Common in brackish water.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 1.</p>
+
+  <p class="ac"><span class="sc">Dubiæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA DUBIA WM.
+  SM.</span></p>
+
+  <p>Valve linear, scarcely, if at all, constricted in the middle, with cuneate, produced, apiculate
+  apices, somewhat recurved; keel very excentric; puncta sometimes partly prolonged, about 9 in 10
+  µ; striæ, 20-24 in 10 µ. L. 93 µ.</p>
+
+  <p>Reported from along the New Jersey coast. I have not seen it. It is generally regarded as
+  fresh-water. Slides sometimes labelled N. dubia are in reality N. litoralis var. delawarensis.</p>
+
+  <p>Pl. <a href="#plate39"><b>39</b></a>, Fig. 5.</p>
+
+  <p class="sp3">The figure is drawn from a specimen from another locality.</p>
+
+  <p class="ac"><span class="sc">Bilobatæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA BILOBATA WM.
+  SM.</span></p>
+
+  <p>Valve linear-lanceolate, constricted in the middle, apiculate at the ends; keel puncta 6 in 10
+  µ, prolonged unequally across part of the valve, the two median sub-remote; striæ, 16 in 10 µ.
+  Frustule oblong, truncate, constricted in the middle. L. 120 µ.</p>
+
+  <p>Shark River, N. J., Chester River, Md.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Figs. 10 and 11.</p>
+
+  <p class="ac"><span class="sc">Epithemioideæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA EPITHEMIOIDES
+  GRUN.</span></p>
+
+  <p>Valve linear, with cuneate, rostrate apices; slightly constricted on the keel side; keel
+  puncta, 8 or 9 in 10 µ, extending as costæ across the valve; striæ delicate, 22 in 10 µ. L. 47
+  µ.</p>
+
+  <p>Brackish water, Long Island Sound.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 21.</p>
+
+  <div><span class="pagenum" id="page119">{119}</span></div>
+
+  <p class="ac"><span class="sc">Grunowia</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA TABELLARIA
+  GRUN.</span></p>
+
+  <p>Valve rhomboidal, inflated in the middle; apices produced; keel puncta extend in costæ across
+  half of the valve, 7 in 10 µ; striæ transverse, about 22 in 10 µ. L. 20 µ.</p>
+
+  <p><i>Dimerogramma sinuatum</i> Thwaites.</p>
+
+  <p><i>Nitzschia sinuata</i> var. <i>tabellaria</i> (Grun.) V. H.</p>
+
+  <p>Schuylkill River. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 7.</p>
+
+  <p class="ac"><span class="sc">Scalares</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA SCALARIS (EHR.) WM.
+  SM.</span></p>
+
+  <p>Valve linear, with obtusely conical apices; costæ transverse, extending more or less to
+  one-third the width of the valve, 3 or 4 in 10 µ; striæ, 9 or 10 in 10 µ, punctate. Length of
+  valve quite variable, up to 480 µ (Cleve).</p>
+
+  <p>A well-known form, abundant in salt marshes and more or less brackish water.</p>
+
+  <p class="sp3">Pl. <a href="#plate33"><b>33</b></a>, Fig. 6. (To the right of the figure is an
+  outline of the valve reduced one-third.)</p>
+
+  <p class="ac"><span class="sc">Insignes</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA INSIGNIS
+  GREG.</span></p>
+
+  <p>Valve nearly linear or linear-lanceolate; apices broad, slightly produced, obtuse; keel puncta
+  extended into short costæ, 4 or 5 in 10 µ; striæ about 14 in 10 µ. Length variable up to 400
+  µ.</p>
+
+  <p>Delaware Bay.</p>
+
+  <p class="sp3">Pl. <a href="#plate33"><b>33</b></a>, Fig. 8.</p>
+
+  <p class="ac"><span class="sc">Bacillaria</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA PAXILLIFER (O. F.
+  MUELLER) HEIBERG</span></p>
+
+  <p>Frustules united in a filament, afterwards free; valve lanceolate with nearly central keel;
+  keel puncta, 7-9 in 10 µ; striæ about 21 in 10 µ. L. 110 µ.</p>
+
+  <p><i>Vibrio paxillifer</i> O. F. Mueller.</p>
+
+  <p><i>Bacillaria paradoxa</i> Gmelin.</p>
+
+  <p><i>Nitzschia paradoxa</i> (Gmelin) Grun.</p>
+
+  <p>Brackish water or streams subject to its influence.</p>
+
+  <p>Pl. <a href="#plate33"><b>33</b></a>, Figs. 13 and 14.</p>
+
+  <p>Otto Frederick Mueller, in 1786, published at Copenhagen a work on "Infusorial Animalcules,"
+  including a description of a Vibrio which he named paxillifer, obviously alluding to the
+  partially-extended frustules bearing at the end a tablet-like bundle. Two years later, Gmelin
+  described the same form as Bacillaria paradoxa, a name still used. Heiberg, however, in 1863,
+  placed the form under Nitzschia where it properly belongs and called it Nitzschia paxillifer (O.
+  F. Mueller). I have adopted Heiberg's name.</p>
+
+  <p class="sp3">Perhaps the most remarkable of all diatoms. Many species possess the power of
+  motion, which, however, is evident only in the free frustule. In N. paxillifer, the movement of
+  the frustules occurs without the loss of continuity or adherence to each other, so that, while at
+  one time the adnate frustules form a narrow filament, like that of Fragilaria, at another <span
+  class="pagenum" id="page120">{120}</span>time they move laterally to their extreme length and form
+  a thread of frustules adherent at their ends, later resuming their original position. The motion
+  is repeated at intervals of from five to ten seconds. No satisfactory explanation of the movement
+  has ever been made. In the filamentous form the frustules adhere to water-plants.</p>
+
+  <p class="ac"><span class="sc">Vivaces</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA FLUMINENSIS
+  GRUN.</span></p>
+
+  <p>Valve lanceolate, apices produced; keel puncta, 4-6 in 10 µ, partly extended in short costæ;
+  striæ transverse, 14-15 in 10 µ, punctate; keel without a pseudo-nodule. L. 73 µ.</p>
+
+  <p>Common at Greenwich Point, Philadelphia.</p>
+
+  <p>Pl. <a href="#plate32"><b>32</b></a>, Fig. 16.</p>
+
+  <p class="sp3">The form here figured is smaller than the type, which is from 130-160 µ in
+  length.</p>
+
+  <p class="ac"><span class="sc">Spathulatæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA SPATHULATA
+  BRÉB.</span></p>
+
+  <p>Frustule linear, truncate, dilated at the ends; zone with longitudinal folds; valve lanceolate,
+  keel central; apices acute, with an elevated appendage; keel puncta, 5-6 in 10 µ; striæ very fine.
+  L. 56 µ.</p>
+
+  <p>Atlantic City and Cape May, N. J. (Lewis).</p>
+
+  <p class="sp3">Pl. <a href="#plate40"><b>40</b></a>, Fig. 3.</p>
+
+  <p class="ac"><span class="sc">Dissipatæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA DISSIPATA (KUETZ.)
+  GRUN.</span></p>
+
+  <p>Valve lanceolate, with sub-rostrate apices; keel excentric; keel puncta about 6 in 10 µ; striæ,
+  14 in 10 µ. L. 20-40 µ.</p>
+
+  <p>Fresh and brackish water.</p>
+
+  <p class="sp3">Pl. <a href="#plate40"><b>40</b></a>, Fig. 7.</p>
+
+  <p class="ac"><span class="sc">Sigmoideæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA MACILENTA
+  GREG.</span></p>
+
+  <p>Frustule sigmoid, truncate at the ends; valve linear, with sub-acute apices and nearly central
+  keel; keel with 5-6 puncta in 10 µ; striæ obscure, about 25 to 28 (?) in 10 µ. Length variable, up
+  to 490 µ.</p>
+
+  <p>As the valve is usually seen when the keel is on the margin, the outline (reduced one-third,
+  shown to the left of the figure) is, as a rule, sigmoid.</p>
+
+  <p>Delaware Bay.</p>
+
+  <p class="sp3">Pl. <a href="#plate33"><b>33</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA VERMICULARIS (KUETZ.)
+  HANTZSCH</span></p>
+
+  <p>Valve linear, sigmoid, attenuated toward the obtuse ends; keel puncta, 9 in 10 µ, quite
+  distinct; striæ very fine. L. 105 µ.</p>
+
+  <p>Fresh-water pools.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 24; Pl. <a
+  href="#plate33"><b>33</b></a>, Fig. 9.</p>
+
+  <div><span class="pagenum" id="page121">{121}</span></div>
+
+  <p class="ac">SIGMATA</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA SIGMA (KUETZ.) WM.
+  SM.</span></p>
+
+  <p>Frustule linear, sigmoid; valve linear, slightly sigmoid, tapering to the sub-acute apices;
+  keel excentric, puncta, 8 in 10 µ; striæ, 20-24 in 10 µ. L. to 250 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate39"><b>39</b></a>, Fig. 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA SIGMATELLA
+  GREG.</span></p>
+
+  <p>Valve linear, sigmoid, slightly attenuated toward the obtuse apices; keel excentric, puncta,
+  8-10 (?) in 10 µ; striæ delicate, 25-30 in 10 µ. L. to 400 µ. The keel puncta are quite
+  obscure.</p>
+
+  <p><i>Nitzschia curvula</i> Wm. Sm.</p>
+
+  <p><i>Nitzschia sigma</i> var. <i>curvula</i> (Wm. Sm.) De Toni.</p>
+
+  <p>Fresh water. Hammonton Pond; May's Landing, N. J.</p>
+
+  <p>Pl. <a href="#plate33"><b>33</b></a>, Figs. 4 and 5.</p>
+
+  <p class="sp3">Gregory remarks that the keel puncta are seen in some specimens. In both of the
+  forms figured I have counted 30 striæ in 10 µ, but, after many examinations, I have not been quite
+  certain about the keel puncta. The general appearance of the valves in any position is that of a
+  Stenopterobia or Surirella anceps, with which it occurs.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA CLAUSII
+  HANTZSCH</span></p>
+
+  <p>Valve linear, slightly sigmoid, tapering to the sub-capitate ends; keel puncta, 11 in 10 µ;
+  striæ subtle. L. 40 µ.</p>
+
+  <p>Abundant in Ridley Creek, Delaware Co. (Palmer).</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 20.</p>
+
+  <p class="ac"><span class="sc">Obtusæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA OBTUSA WM.
+  SM.</span></p>
+
+  <p>Frustule sigmoid, rounded at the ends; keel somewhat excentric, inflexed in the middle, the two
+  median puncta distant; keel puncta, 5-6 in 10 µ; striæ, 26 in 10 µ. L. to 300 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate39"><b>39</b></a>, Fig. 16.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA OBTUSA VAR. FLEXELLA H.
+  L. SMITH</span></p>
+
+  <p>Valve more attenuate at the ends than the type and smaller.</p>
+
+  <p class="sp3">Pl. <a href="#plate39"><b>39</b></a>, Fig. 14.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA OBTUSA VAR.
+  SCALPELLIFORMIS GRUN.</span></p>
+
+  <p>Valve linear, with apices unilaterally truncate; keel excentric; keel puncta, 8 in 10 µ; striæ,
+  26 in 10 µ. L. 48 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 17.</p>
+
+  <div><span class="pagenum" id="page122">{122}</span></div>
+
+  <p class="ac"><span class="sc">Spectabiles</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA SPECTABILIS VAR.
+  AMERICANA GRUN.</span></p>
+
+  <p>Frustule linear, slightly constricted in the middle, with sub-cuneate ends; valve linear,
+  slightly arcuate, tapering to the sub-rostrate ends; keel excentric, keel puncta sometimes
+  confluent, 4-6 in 10 µ, prolonged into short costæ; striæ distinct, 14 in the middle, 18 at the
+  ends in 10 µ (but variable in different specimens). L. 186 µ.</p>
+
+  <p>Blue clay, especially at Tioga St.</p>
+
+  <p>Pl. <a href="#plate33"><b>33</b></a>, Fig. 3; Pl. <a href="#plate39"><b>39</b></a>, Fig. 1.</p>
+
+  <p>This is, probably, one of the most beautiful of the Nitzschiæ. It sometimes, according to De
+  Toni, reaches a length of 520 µ.</p>
+
+  <p class="sp3">Grunow states that his variety is found in the S. Bridgeton deposit. In a slide of
+  M&#x0153;ller labelled "Bridgeton, Maine," I find specimens identical in every respect with the
+  Philadelphia form.</p>
+
+  <p class="ac"><span class="sc">Lineares</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA LINEARIS (AG.) WM.
+  SM.</span></p>
+
+  <p>Valve linear, slightly inflexed in the middle; keel excentric; keel puncta, 8-9 in 10 µ, the
+  two median distant; striæ about 30 in 10 µ. Frustules in zone view narrowed toward the ends,
+  truncate. L. 75 µ.</p>
+
+  <p>Very common in fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 18. Fig. 20, Pl. <a
+  href="#plate40"><b>40</b></a>, a transverse section of frustule.</p>
+
+  <p class="ac"><span class="sc">Lanceolatæ</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA PALEA (KUETZ.) WM.
+  SM.</span></p>
+
+  <p>Valve linear-lanceolate, slightly rostrate at the apices; keel puncta, 10 in 10 µ, the median
+  not distant; striæ, 33-36 in 10 µ; zone view linear, with rounded ends. L. 25-65 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 15.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA AMPHIBIA
+  GRUN.</span></p>
+
+  <p>Valve lanceolate, apices sometimes slightly produced, rounded; keel puncta, 8-9 in 10 µ; striæ,
+  16 in 10 µ. L. 20-32 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Figs. 14 and 25.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA COMMUNIS
+  RAB.</span></p>
+
+  <p>Frustule linear, slightly attenuated at the obtuse ends; valve elliptical-lanceolate,
+  attenuated toward the obtuse ends; keel puncta, 12 in 10 µ; striæ more than 30 in 10 µ. L. 35
+  µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate32"><b>32</b></a>, Fig. 19.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA INTERMEDIA
+  HANTZSCH</span></p>
+
+  <p>Valve linear-lanceolate; keel puncta, 8 in 10 µ; striæ about 24 in 10 µ. L. 100 µ.</p>
+
+  <p>Crum Creek. Not common.</p>
+
+  <p class="sp3">Pl. <a href="#plate33"><b>33</b></a>, Fig. 2.</p>
+
+  <div><span class="pagenum" id="page123">{123}</span></div>
+
+  <p class="ac"><span class="sc">Nitzschiella</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA LONGISSIMA (BRÉB.)
+  RALFS</span></p>
+
+  <p>Valve linear-lanceolate, with exceedingly long horns or beaks; keel puncta about 10 in 10 µ;
+  striæ about 16 in 10 µ. L. to 500 µ.</p>
+
+  <p>Shark River, N. J.</p>
+
+  <p>Pl. <a href="#plate33"><b>33</b></a>, Fig. 1.</p>
+
+  <p>Forma parva V. H.&mdash;Keel puncta, 10-12 in 10 µ. L. 70 µ.</p>
+
+  <p>East Park Reservoir, Philadelphia.</p>
+
+  <p>Pl. <a href="#plate33"><b>33</b></a>, Fig. 10.</p>
+
+  <p>Differs from N. closterium (Ehr.) Wm. Sm. in the keel puncta.</p>
+
+  <p class="sp3">The type form occurs in brackish and salt water. The occurrence of the variety in
+  fresh water is another instance of the finding of presumably brackish forms in the water supply of
+  the city. If these cases prove to be unusual, it may be because of one of two reasons. The
+  Schuylkill River, before the building of the dam at Fairmount, was tidal as far as the Falls of
+  Schuylkill, and brackish influences, while not now existent, may have caused the growth of forms
+  which now survive. Another reason may be that the opening of the locks at Fairmount Dam may cause
+  a slight admission of brackish forms from tidal water below. The abundance of the brackish species
+  appears to indicate that the first reason is the more plausible.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA REVERSA WM.
+  SM.</span></p>
+
+  <p>Valve lanceolate extended into beaks or horns curving in opposite directions; keel puncta not
+  evident; striæ, "20-26" in 10 µ. L. 70 µ.</p>
+
+  <p>Brackish water. Abundant in Duck Creek, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate33"><b>33</b></a>, Fig. 11.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">NITZSCHIA ACICULARIS (KUETZ.) WM.
+  SM.</span></p>
+
+  <p>Valve lanceolate, with beaks or horns about half the length of the median part of the valve;
+  keel puncta, 18 in 10 µ; striæ exceedingly delicate, "about 40 in 10 µ." L. 45 µ.</p>
+
+  <p>Fresh water. Darby Creek.</p>
+
+  <p class="sp3">Pl. <a href="#plate33"><b>33</b></a>, Fig. 12.</p>
+
+  <h3 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Hom&#x0153;ocladia</span> <span
+  class="smaller">AG.</span> (1827)</h3>
+
+  <p class="ac">(homoios, like, and clados, a branch)</p>
+
+  <p class="sp3">Frustules like Nitzschia, but enclosed in branching or simple tubes.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">HOM&#x0152;OCLADIA FILIFORMIS WM.
+  SM.</span></p>
+
+  <p>Frustule linear, tumid in the middle, obtuse at the ends; valve linear-lanceolate, with
+  somewhat acute apices; keel central or nearly so; keel puncta, 8 in 10 µ; striæ delicate. L. 108
+  µ.</p>
+
+  <p>Fresh and brackish water. Newark, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate33"><b>33</b></a>, Fig. 15.</p>
+
+  <div><span class="pagenum" id="page124">{124}</span></div>
+
+  <h3 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Surirella</span> <span
+  class="smaller">TURPIN</span> (1828)</h3>
+
+  <p class="ac">(named after Dr. Suriray, a physician of Havre)</p>
+
+  <p>Valve linear, elliptical or ovate; pseudoraphe linear or lanceolate; a marginal keel forming
+  wings or alæ seen in zone view; costæ short or reaching the pseudoraphe, frequently with
+  intercostal striæ more or less evident.</p>
+
+  <p>The genus is divided by Grunow according to the length and form of the costæ. I include
+  Stenopterobia.</p>
+
+  <p>Section 1.&mdash;Costæ of nearly equal width throughout, reaching the pseudoraphe.</p>
+
+  <p>Section 2.&mdash;Costæ short or marginal.</p>
+
+  <p>Section 3.&mdash;Costæ dilated at the margin, attenuated toward the pseudoraphe.</p>
+
+  <p>Section 4.&mdash;Valve having the appearance of Nitzschia, with inconspicuous alæ
+  (Stenopterobia).</p>
+
+  <p>The endochrome consists of two laminate chromatophores, one on each valve.</p>
+
+  <p class="sp3">The auxospores are single, originating from the union of two frustules (H. L.
+  Smith).</p>
+
+  <p class="ac"><span class="sc">Section 1</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA BISERIATA (EHR.)
+  BRÉB.</span></p>
+
+  <p>Valve lanceolate, subacute at the ends; costæ robust, about 2 in 10 µ, parallel in the middle,
+  radiate at the ends; pseudoraphe narrow. L. 100 µ.</p>
+
+  <p><i>Surirella bifrons</i> Ehr.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate39"><b>39</b></a>, Fig. 12; Pl. <a
+  href="#plate35"><b>35</b></a>, Fig. 2 (smaller form).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA LINEARIS WM.
+  SM.</span></p>
+
+  <p>Valve linear, with cuneate ends, slightly constricted in the middle; costæ parallel, 2-3 in 10
+  µ. L. 90 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate35"><b>35</b></a>, Fig. 8.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA AMPHIOXYS WM.
+  SM.</span></p>
+
+  <p>Valve oblong-linear, with cuneate ends; pseudoraphe narrow; costæ, 3-4 in 10 µ; striæ, 14-16 in
+  10 µ, somewhat radiate. L. 34-54 µ.</p>
+
+  <p><i>Surirella m&#x0153;lleriana</i> Grun.</p>
+
+  <p>Fresh and brackish water. Common along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate35"><b>35</b></a>, Figs. 12 and 13.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA ROBUSTA EHR.</span></p>
+
+  <p>Valve linear-ovate; pseudoraphe wide; alæ prominent; costæ wide, 1¼ in 10 µ. Frustule in zone
+  view clavate. L. 200-365 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate36"><b>36</b></a>, Fig. 2.</p>
+
+  <div><span class="pagenum" id="page125">{125}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA SPLENDIDA (EHR.)
+  KUETZ.</span></p>
+
+  <p>Valve ovate; costæ, 1½ to 2 in 10 µ; pseudoraphe linear, narrow. L. 125-200 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p>Pl. <a href="#plate35"><b>35</b></a>, Fig. 3.</p>
+
+  <p class="sp3">S. splendida is smaller than S. robusta and wider in proportion, but, as
+  intermediate forms occur, it is difficult to distinguish between them.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA ELEGANS EHR.</span></p>
+
+  <p>Valve ovate, rounded at one end and acute at the other; pseudoraphe lanceolate, narrow; costæ,
+  1½ in 10 µ; striæ subtle, 22 in 10 µ. Frustule in zone view cuneate. L. 180-220 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate36"><b>36</b></a>, Fig. 1.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA STRIATULA
+  TURPIN</span></p>
+
+  <p>Valve broad, obovate or elliptical, rounded at each end; costæ, 1¼ in 10 µ, curved at the ends;
+  striæ, 14 in 10 µ. Frustule in zone view cuneate; marginal alæ quite robust. L. 100-160 µ.</p>
+
+  <p>Blue clay. Brackish water.</p>
+
+  <p>Pl. <a href="#plate34"><b>34</b></a>, Fig. 1.</p>
+
+  <p class="sp3">In the specimen figured, the outline is exactly elliptical, although the species is
+  usually conical at one end.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA GEMMA EHR.</span></p>
+
+  <p>Valve ovate or ovate-elliptical, rounded at each end, sometimes asymmetrical along the
+  longitudinal axis; pseudoraphe very narrow; costæ distant, at irregular intervals, about 2 in 10
+  µ, somewhat radiate, reaching the pseudoraphe; striæ, 20 in 10 µ, punctate. Frustule in zone view
+  cuneate. L. 70-120 µ.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate36"><b>36</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA TENERA GREG.</span></p>
+
+  <p>Valve ovate; pseudoraphe narrow, well-defined; costæ indistinct, 2½ in 10 µ, their margins
+  invisible; striæ about 14 in 10 µ, punctate, more evident near the margin. L. 90 µ.</p>
+
+  <p><i>Surirella diaphana</i> Bleisch.</p>
+
+  <p>Pavonia, N. J., artesian well.</p>
+
+  <p>Pl. <a href="#plate35"><b>35</b></a>, Fig. 6.</p>
+
+  <p class="sp3">The figure is that of the var. nervosa A. S. (Atlas, Pl. 23, Fig. 15), which
+  differs from the type in having the position of the costæ indicated by scattered puncta.</p>
+
+  <div><span class="pagenum" id="page126">{126}</span></div>
+
+  <p class="ac"><span class="sc">Section 2</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA GUATIMALENSIS
+  EHR.</span></p>
+
+  <p>Valve ovate; pseudoraphe very narrow and indistinct; costæ short, marginal, 2-2½ in 10 µ,
+  absent from the rounded end. L. 120 µ.</p>
+
+  <p><i>Surirella cardinalis</i> Kitton.</p>
+
+  <p>Smith's Island, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate36"><b>36</b></a>, Fig. 5.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA OVALIS BRÉB.</span></p>
+
+  <p>Valve ovate; costæ short, marginal, radiate, 3-6 in 10 µ, often unequal; central area ovate,
+  indistinctly costate; striæ scarcely visible, about 18 in 10 µ; pseudoraphe narrow. L. 45-93
+  µ.</p>
+
+  <p><i>Surirella davidsonii</i> A. S.</p>
+
+  <p>Fresh or brackish water.</p>
+
+  <p>Pl. <a href="#plate35"><b>35</b></a>, Fig. 5; Pl. <a href="#plate39"><b>39</b></a>, Fig.
+  11.</p>
+
+  <p class="sp3">The smaller specimen is from the Delaware River, and the larger from the Hudson
+  River.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA CRUMENA
+  BRÉB.</span></p>
+
+  <p>Valve nearly orbicular; costæ short, marginal, radiate; pseudoraphe narrow, indistinct; central
+  area indistinctly costate, sometimes interrupted.</p>
+
+  <p>On account of the extreme confusion in the names of many forms which appear to be variations of
+  S. ovalis, I have followed Van Heurck in retaining the original names as specific. De Toni gives
+  S. crumena as a variety of S. ovalis.</p>
+
+  <p>Fresh and brackish water. Quite common in the Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate35"><b>35</b></a>, Fig. 4.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA PINNATA WM.
+  SM.</span></p>
+
+  <p>Valve ovate or oblong-ovate; costæ reaching the linear pseudoraphe, about 6 in 10 µ. L. 40
+  µ.</p>
+
+  <p><i>Surirella ovalis</i> var. <i>pinnata</i> (Wm. Sm.) De Toni.</p>
+
+  <p>S. pinnata is the type of a number of small forms usually found together, including S.
+  panduriformis, S. angusta and S. minuta.</p>
+
+  <p>Fresh water. Media (Palmer).</p>
+
+  <p>Pl. <a href="#plate36"><b>36</b></a>, Fig. 7; Fig. 9 (abnormal).</p>
+
+  <p class="sp3">Var. minuta, a small form of S. pinnata, occurs with the type.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA PANDURIFORMIS WM.
+  SM.</span></p>
+
+  <p>Valve linear-oblong, with rounded ends, more or less constricted in the middle; otherwise as in
+  S. pinnata. L. 54 µ.</p>
+
+  <p>Fresh water.</p>
+
+  <p class="sp3">Pl. <a href="#plate36"><b>36</b></a>, Fig. 6.</p>
+
+  <div><span class="pagenum" id="page127">{127}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA ANGUSTA
+  KUETZ.</span></p>
+
+  <p>Valve linear, with cuneate ends; otherwise as in S. pinnata.</p>
+
+  <p>Fresh water.</p>
+
+  <p>Pl. <a href="#plate36"><b>36</b></a>, Fig. 8.</p>
+
+  <p class="sp3">S. pinnata, S. panduriformis, and S. angusta have a narrow central area, and differ
+  from S. ovalis which has short costæ.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA OBLONGA EHR.
+  ?</span></p>
+
+  <p>Valve elliptical-lanceolate, with obtuse ends; costæ, marginal, 2½ in 10 µ; median area
+  granulate; pseudoraphe narrow, lanceolate, scarcely visible; striæ about 18 in 10 µ. L. 60 µ.</p>
+
+  <p>Blue clay. Rare.</p>
+
+  <p>Pl. <a href="#plate35"><b>35</b></a>, Fig. 9.</p>
+
+  <p class="sp3">This has the outline and appearance of S. oblonga Ehr. (Mik. Pl. 15, Fig. 48), but
+  the costæ are closer.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA RECEDENS A.
+  S.</span></p>
+
+  <p>Valve ovate; costæ, 2-2½ in 10 µ; pseudoraphe narrow, not reaching the ends of the valve;
+  intercostal spaces more evident near the middle. L. 50 µ.</p>
+
+  <p>Blue clay. Not uncommon.</p>
+
+  <p class="sp3">Pl. <a href="#plate35"><b>35</b></a>, Fig. 7.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA CRUCIATA A.
+  S.</span></p>
+
+  <p>Valve ovate; pseudoraphe very narrow; costæ, 2 in 10 µ; the outline of several of the median
+  costæ strongly emphasized, while the other costæ are indistinct. L. 54 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p class="sp3">Pl. <a href="#plate35"><b>35</b></a>, Fig. 10.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA GRACILIS
+  GRUN.</span></p>
+
+  <p>Valve linear, with sub-cuneate ends, slightly constricted in the middle; pseudoraphe very
+  narrow; costæ, 6-7 in 10 µ; transverse striæ about 26 in 10 µ, punctate. L. 75 µ.</p>
+
+  <p>According to De Toni (p. 598), this form is a Nitzschia. It has, however, a narrow
+  pseudoraphe.</p>
+
+  <p>Pavonia, N. J., artesian well. Rare.</p>
+
+  <p class="sp3">Pl. <a href="#plate35"><b>35</b></a>, Fig. 11.</p>
+
+  <p class="ac"><span class="sc">Section 3</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA FASTUOSA
+  EHR.</span></p>
+
+  <p>Valve ovate; costæ about 1-2 in 10 µ, dilated at the margin and contracting at about one-fourth
+  the distance toward the middle; area, ovate-lanceolate; pseudoraphe, narrow and indistinct;
+  intercostate striæ more evident near the margin, 19 in 10 µ, becoming again evident in a narrow
+  band about one-half the distance to the pseudoraphe. L. 50-120 µ.</p>
+
+  <p>Along the coast. More common southward.</p>
+
+  <p class="sp3">Pl. <a href="#plate35"><b>35</b></a>, Fig. 1.</p>
+
+  <div><span class="pagenum" id="page128">{128}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA FEBIGERII
+  LEWIS</span></p>
+
+  <p>Valve ovate-lanceolate; costæ about 2½ in 10 µ with punctate interspaces extending half the
+  distance toward the median hyaline area, which is divided longitudinally on each side of the
+  narrow pseudoraphe by two longitudinal bands composed of short, transverse, irregular, punctate
+  lines.</p>
+
+  <p>Along the coast.</p>
+
+  <p class="sp3">Pl. <a href="#plate36"><b>36</b></a>, Fig. 3.</p>
+
+  <p class="ac"><span class="sc">Section 4 (Stenopterobia)</span></p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA ANCEPS LEWIS</span></p>
+
+  <p>Frustule linear, straight or nearly so; valve sigmoid with rounded apices; costæ marginal,
+  nearly obsolete; striæ distinct, about 15 in 10 µ; pseudoraphe wide. L. to 320 µ.</p>
+
+  <p>Hammonton Pond and Tom's River, N. J.</p>
+
+  <p class="sp3">Pl. <a href="#plate34"><b>34</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA INTERMEDIA
+  LEWIS</span></p>
+
+  <p>Frustule linear, straight, widened at the truncate ends; valve linear, sigmoid, tapering to the
+  sub-acute ends; costæ about 5 in 10 µ; striæ about 20 in 10 µ. L. variable.</p>
+
+  <p>Hammonton Pond, N. J.</p>
+
+  <p>Pl. <a href="#plate34"><b>34</b></a>, Fig. 3; Pl. <a href="#plate39"><b>39</b></a>, Fig. 9
+  (zone view).</p>
+
+  <p>This, perhaps, is forma sub-acuta Fricke.</p>
+
+  <p class="sp3">Fig. 7, Pl. <a href="#plate34"><b>34</b></a>, is probably a small form of S.
+  intermedia, from Willistown, Pa. It resembles a Nitzschia.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA DELICATISSIMA
+  LEWIS</span></p>
+
+  <p>Frustule linear, rounded at the ends; valve linear-lanceolate, sometimes very slightly
+  constricted in the middle, with acute apices; costæ, 5 in 10 µ; striæ about 20 in 10 µ;
+  pseudoraphe well defined, lanceolate. L. to 90 µ.</p>
+
+  <p>Fresh water. Newtown Square.</p>
+
+  <p class="sp3">Pl. <a href="#plate34"><b>34</b></a>, Figs. 5 and 6 (small forms).</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">SURIRELLA ARCTISSIMA A.
+  S.</span></p>
+
+  <p>Valve linear, tapering to the sub-acute ends; costæ marginal, 5 in 10 µ; striæ, 18 in 10 µ;
+  pseudoraphe not evident. L. 184 µ.</p>
+
+  <p>May's Landing, N. J.</p>
+
+  <p>Pl. <a href="#plate34"><b>34</b></a>, Fig. 4.</p>
+
+  <p class="sp3">Fig. 10, Pl. <a href="#plate39"><b>39</b></a>, is a small form from Newtown Square,
+  Pa., in which the length is 86 µ, the costæ 5 and the striæ 16 in 10 µ.</p>
+
+  <h3 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Podocystis</span> <span
+  class="smaller">KUETZ.</span> (1844)</h3>
+
+  <p class="ac">(pous, a foot, and cystis, a bag)</p>
+
+  <p class="sp3">Frustules cuneate, similar to Surirella, but attached by short stipes to other
+  algæ; valve obovate.</p>
+
+  <div><span class="pagenum" id="page129">{129}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">PODOCYSTIS ADRIATICA
+  KUETZ.</span></p>
+
+  <p>Valve nearly symmetrical, obovate, with transverse costæ about 4 in 10 µ, alternating with
+  double rows of coarse puncta; median line distinct, linear. L. 43 µ.</p>
+
+  <p><i>Podocystis americana</i> Bail.</p>
+
+  <p>Hell Gate, N. Y.</p>
+
+  <p class="sp3">Pl. <a href="#plate40"><b>40</b></a>, Fig. 6.</p>
+
+  <h3 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Cymatopleura</span> <span
+  class="smaller">WM. SM.</span> (1851)</h3>
+
+  <p class="ac">(cuma, a wave, and pleura, a side)</p>
+
+  <p>Valve elliptical; surface transversely undulate, with short, marginal costæ. Frustule in zone
+  view linear, with undulated sides.</p>
+
+  <p class="sp3">Auxospore formation as in Surirella.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMATOPLEURA SOLEA (BRÉB.) WM.
+  SM.</span></p>
+
+  <p>Valve oblong, with cuneate apices, constricted in the middle; costæ about 6 in 10 µ; striæ, 10
+  in 10 µ; pseudoraphe scarcely visible. L. 50-300 µ.</p>
+
+  <p>Blue clay. Common in the Hudson River.</p>
+
+  <p class="sp3">Pl. <a href="#plate34"><b>34</b></a>, Figs. 8 and 9.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMATOPLEURA ELLIPTICA (BRÉB.)
+  WM. SM.</span></p>
+
+  <p>Valve elliptical; marginal costæ short, 3 in 10 µ; striæ delicate, 18 in 10 µ; undulations four
+  or more. L. 70-140 µ.</p>
+
+  <p>Blue clay.</p>
+
+  <p>Pl. <a href="#plate37"><b>37</b></a>, Fig. 1.</p>
+
+  <p><i>Forma spiralis.</i>&mdash;Valve ovate, swelled into curved ridges at the lower end, with a
+  contraction of the valve.</p>
+
+  <p>Port Penn, Delaware River.</p>
+
+  <p class="sp3">Pl. <a href="#plate37"><b>37</b></a>, Fig. 2.</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CYMATOPLEURA MARINA
+  LEWIS</span></p>
+
+  <p>Frustule linear, with numerous undulations, ends apiculate; valve linear-lanceolate, with acute
+  ends; striæ transverse, punctate at unequal intervals, from 16-18 in 10 µ. L. 43 µ.</p>
+
+  <p>East River, N. Y.</p>
+
+  <p>Pl. <a href="#plate37"><b>37</b></a>, Figs. 3 and 4.</p>
+
+  <p class="sp3">Lewis states that the ends are more or less truncate. I do not find them so.</p>
+
+  <h3 class="ac" style="margin-bottom:1.1ex;"><span class="sc">Campylodiscus</span> <span
+  class="smaller">EHR.</span> (1841)</h3>
+
+  <p class="ac">(campulos, curved like a saddle)</p>
+
+  <p>Valve orbicular or sub-orbicular, with costæ or punctate rays converging from the circumference
+  toward the hyaline centre, which sometimes appears like a pseudoraphe. Frustule of two
+  saddle-shaped valves at right angles to each other. The zone view may be of almost any shape
+  according to position.</p>
+
+  <p class="sp3">Endochrome consists of two bands, each lining the inner surface of each valve.
+  Auxospore and conjugation unknown.</p>
+
+  <div><span class="pagenum" id="page130">{130}</span></div>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CAMPYLODISCUS ECHENEIS
+  EHR.</span></p>
+
+  <p>Valve sub-orbicular, saddle-shaped; costæ indistinct, short, marginal; rows of round or
+  elongated puncta converge toward the lanceolate, hyaline median space. Diam. 80-140 µ.</p>
+
+  <p><i>Campylodiscus argus</i> Bail.</p>
+
+  <p>Blue clay. Reservoir at Thompson and Twenty-sixth Sts., Phila.</p>
+
+  <p>Pl. <a href="#plate37"><b>37</b></a>, Fig. 6.</p>
+
+  <p class="sp3">This form, usually considered as brackish and marine, is occasionally found in
+  fresh water. According to Deby, it is fossil in the "Champlain deposit of N. A."</p>
+
+  <p class="ac" style="margin-bottom:1.6ex;"><span class="smaller">CAMPYLODISCUS HIBERNICUS
+  EHR.</span></p>
+
+  <p>Valve irregularly orbicular; costæ, 40-60, about 2 in 10 µ, wide at the margin and attenuated
+  toward the centre which is somewhat quadrate; the radials rough with minute apiculi.</p>
+
+  <p>Pensauken, N. J., artesian well.</p>
+
+  <p class="sp4">Pl. <a href="#plate37"><b>37</b></a>, Fig. 5.</p>
+
+  <div><span class="pagenum" id="page131">{131}</span></div>
+
+  <h1 class="sp3 ac" style="margin-bottom:2ex;"><span class="x-larger">APPENDIX</span></h1>
+
+  <p class="ac"><span class="sc">Collection and Preparation of Diatoms</span></p>
+
+  <p>It is assumed that every student of the Diatomaceæ has a general knowledge of the collection,
+  preparation, mounting and examination of material. For the novice, however, the following methods,
+  used by the author for many years, may be of service.</p>
+
+  <p><i>Collection of Fresh-water Material.</i>&mdash;The yellow film on the inside of aquaria
+  always contains small species. Stems of water-plants near the shores of ponds and the submerged
+  roots, the brownish coating of rocks in streams and water-falls, fountains, and water-troughs, are
+  prolific. At all times of the year, some diatoms may be found in a thin layer upon the mud of
+  rivers or creeks. In the spring, brown patches of mud, filled with bubbles, floating near the
+  shore in ponds, or coming down with the current in rivers, are rich in various forms. Within the
+  limits assigned to our district, I have made collections in the following localities: Schuylkill
+  River, including the region near Fairmount Dam, several reservoirs and the water-supply; the
+  Wissahickon and Fairmount Park, Darby, Crum and Ridley Creeks, the Neshaminy and the Brandywine;
+  meadow pools and rivulets near the city; the upper Delaware, the Water Gap and numerous cascades
+  northward; the Shawangunk Mountains and the Poconos; many parts of New Jersey along the coast; the
+  Pine Barren region, the Hammonton, Atsion and Kirkwood Ponds and the swamps near Atco.</p>
+
+  <p>In the collection of fresh-water material, it is well to be provided with a number of small
+  bottles. Take a handful of the water-plants or algæ, and squeeze the material into the bottles,
+  or, lacking a bottle, wrap it in paper. With a small forceps it is possible to detach minute
+  quantities of a pure gathering which may not need further preparation beyond burning to a red heat
+  on the cover-glass before mounting. A malacca cane, with extending rod to which may be screwed a
+  bottle, net, spoon or hook, is useful on a long trip. If it is impossible to separate the thin
+  film of diatoms from the mud in the bed of streams, dip up the surface mud with one bottle, allow
+  to settle a few minutes, then pour off the supernatant liquid, which will be comparatively free
+  from sand, into another bottle. It must be confessed, however, that the mud in streams near
+  Philadelphia contains a large quantity of fine mica which, in some instances, it is impossible to
+  remove.</p>
+
+  <p><i>Collection of Marine Material.</i>&mdash;Shell scrapings, the stomachs of fish, marine algæ,
+  especially the brown and red algæ, the hulls of vessels, mud from anchors and dredgings, are all
+  sources which may prove valuable. In the sand ripples, after the tide recedes, a yellowish-brown
+  deposit will be noticed. This should be taken up carefully with a spoon and placed in a bottle;
+  the sand will settle at once and a very pure gathering will be held in suspension in the water.
+  Such collections may be made along the entire coast of New Jersey on sunny days in summer. In salt
+  meadows near Absecon and Hackensack, large quantities of diatoms, including Pleurosigma, may be
+  obtained in the yellow scum floating on the surface.</p>
+
+  <p><i>The Blue Clay Deposit.</i>&mdash;The blue clay occurs as a pre- or post-glacial deposit in
+  the bed of the ancient Delaware River, and, at depths varying usually from fifteen to forty feet
+  below the surface, has been obtained from artesian wells at Pavonia, Pensauken and Gloucester, N.
+  J., also at Port Penn on the Delaware, and especially from the dredgings <span class="pagenum"
+  id="page132">{132}</span>made by the removal of Smith's Island opposite the city. In the city
+  proper, it may be stated briefly that material may be found in a stratum of very light blue clay
+  at a depth varying from twenty to sixty feet in many places south of Arch St. east of Broad St.,
+  and also along the beds of ancient rivulets near Tioga St., at Sixteenth St., and in certain other
+  places which were probably subject to tidal overflow. One of the best collections was made along
+  the bank of the Schuylkill at the east end of Walnut St. Bridge, at a depth of thirteen feet below
+  the surface. Excavations for the Reading Terminal and the Subway and several buildings, as the
+  Bingham House, have furnished numerous specimens.</p>
+
+  <p><i>Cleaning the Material.</i>&mdash;Some gatherings may be so pure as to be ready for mounting
+  when treated with dilute alcohol and oil of cloves. If, when gathered, the diatoms are immersed in
+  a saturated solution of picric acid for several days, they may be stained with carmine or
+  methylene blue, or whatever may be required to emphasize the contents of the frustules, including
+  the endochrome and the pyrenoids. After staining, pass as rapidly as expedient through the
+  treatment with dilute alcohol and oil of cloves, and mount in benzol balsam, avoiding heat. A hot
+  solution of mercuric bichloride is sometimes used for the preservation of the endochrome, although
+  washing is needed before mounting. For the particular stain considered best for certain details of
+  structure, it will be advisable to consult works on Micro-Chemistry or Heinzerling (<i>l. c.</i>).
+  The stains of most importance are carmine, methylene blue, hæmatoxylin, gold chloride and Bismarck
+  brown.</p>
+
+  <p>Whatever method may be used in staining, the identification of forms is impossible, in most
+  cases, unless the valves are carefully cleaned and the cell-contents destroyed. For this purpose
+  provide a casserole holding from five to eight ounces, an iron tripod stand with alcohol lamp,
+  several six-inch test-tubes, preferably those with a standard base, fitted with pure rubber corks.
+  Take the material as free from twigs, dead leaves, sand, and other matter as possible, place it in
+  the casserole, and add about the same quantity of nitric acid. Boil for twenty minutes and then
+  add about half a teaspoonful of powdered bichromate of potash, stirring with a glass rod. Then
+  take a beaker-glass partly filled with water and pour into it slowly the liquid which has been
+  allowed to cool a short time, whirling the casserole to cause the concentration of sand in the
+  centre. Allow the material to settle for half an hour or longer, according to the amount of
+  diatoms and their size. Pour off the water, add more water, and place in a test-tube. Repeat the
+  decantation, shaking the test-tube, closed with a rubber cork, vigorously each time. From time to
+  time whirl the diatoms in the casserole and throw away the sand collected in the centre. By
+  repeating the decantation, shaking and whirling, the deposit will be found to consist almost
+  entirely of diatoms. It may be necessary to repeat the boiling in the acid and bichromate. If,
+  however, any detritus other than sand is noted, boil in sulphuric acid and add from time to time
+  minute pinches of powdered chlorate of potash, being careful to protect the eyes by holding a
+  piece of glass before them; otherwise the explosions which occur are likely to throw some of the
+  boiling acid into the eyes and destroy the sight. The material, when clean, should be white or, in
+  the case of Synedra, yellowish. It is quite easy to construct a box fitted with the proper
+  apparatus for boiling and provided with a glass door for observation, and a method of introducing
+  the chlorate of potash through a small aperture or tube. The box may be placed in the garden or
+  fastened outside of a window so that the poisonous fumes may be carried off.</p>
+
+  <p>An excellent method, in the case of larger forms, is to boil the material already cleaned by
+  the acid in water to which a few shavings of coarse brown soap are added. The difference in
+  density will hold in suspension any flocculent matter, and while many of the smaller <span
+  class="pagenum" id="page133">{133}</span>forms will not settle, the others will be perfectly
+  cleaned. When satisfied with the cleaning, preserve the stock material in part alcohol and, in
+  using, pour into a smaller bottle the amount required, replace the dilute alcohol with distilled
+  water, and mount as directed. It often happens that gatherings are made consisting almost entirely
+  of sand. Attempts at cleaning in the usual way will cause the loss of nearly all of the diatoms.
+  In this case, after the material has been treated with acid until nothing remains but sand and a
+  few diatoms, the mechanical finger must be used.</p>
+
+  <p>In the cleaning of marine deposits, various methods may be required. In the case of partly
+  siliceous species, washing in pure water repeatedly is all that can be done. The larger and
+  heavier diatoms may be separated from the sand by elutriation or by whirling in a casserole, by
+  rocking in a shallow dish the shape of a watch crystal, or by pouring slowly over a strip of
+  plate-glass at least two feet in length inclined at an angle of thirty degrees. The sand will
+  cling to the glass, while the greater portion of the diatoms will run off. Where particles of
+  shells or foraminifera are present, a preliminary boiling in hydrochloric acid is advisable. In
+  all marine gatherings, the salt should first be washed out before proceeding with the
+  cleaning.</p>
+
+  <p>For hardened masses of clay and for fossil deposits, it is necessary to boil in carbonate of
+  soda and follow with the acid treatment. Citric acid and acetate of potash used alternately in
+  boiling may be tried. Soaking for a time in acetate of potash and allowing the material to
+  deliquesce for a week before further process, has proved successful in some instances. The
+  repetition of several methods and the gentle breaking of the harder masses with the point of a
+  needle will disintegrate almost any diatomaceous earth, but, as a last resort for refractory
+  deposits, boil in pure water, add a piece of caustic potash about the size of a pea, continue the
+  boiling not more than thirty seconds longer, and pour instantly into dilute hydrochloric acid;
+  otherwise the diatoms will be destroyed. Afterwards proceed with the usual treatment.</p>
+
+  <p><i>Slides and Covers.</i>&mdash;Take half an ounce of No. 1 covers, circles, and place them in
+  a wide-mouthed bottle. Add a portion of the following mixture (Dr. Carl Seiler's formula):</p>
+
+  <table class="sp2 mc" title="Dr. Carl Seiler's formula" summary="Dr. Carl Seiler's formula">
+    <tr>
+      <td class="pr2">Bichromate of potash</td>
+      <td>2 oz.</td>
+    </tr>
+    <tr>
+      <td>Sulphuric acid</td>
+      <td>3 fl. oz.</td>
+    </tr>
+    <tr>
+      <td>Water</td>
+      <td>25 fl. oz.</td>
+    </tr>
+  </table>
+
+  <p>Shake the bottle in order that the surfaces of the covers may be fully exposed to the action of
+  the acid, and set aside for several hours. Decant the solution, add water repeatedly until all
+  traces of the mixture are removed, and keep the circles in the bottle in fifty-per cent. alcohol.
+  When needed, take out a circle with forceps and dry on a linen cloth.</p>
+
+  <p>The slides may be treated in the same way, or they may be easily prepared by immersion in a
+  solution of washing soda, and then washed and dried. This process may be used in cleaning the
+  balsam or styrax from old slides.</p>
+
+  <p><i>Preparation of Strewn Mounts.</i>&mdash;Place several covers on the mounting stand. With a
+  dipping tube, cover each circle with distilled water, and add a small drop of the prepared
+  diatoms, being careful to avoid any vibration of the stand. Heat the stand until small bubbles
+  begin to appear, remove the lamp, and allow the water to evaporate. If the above method is
+  carefully followed, the diatoms will be deposited in an even layer, provided the material is not
+  too dense. Take a slide, centre it, and place a small amount of styrax on the centre. Invert the
+  prepared cover, and gently place it upon the styrax. Heat the slide <span class="pagenum"
+  id="page134">{134}</span>on the mounting stand until the styrax bubbles and then allow to cool. If
+  bubbles still remain, heat again until they disappear. It is well to mount several slides more
+  than required, as some may be imperfect.</p>
+
+  <p><i>Preparation of Selected Mounts.</i>&mdash;Take a slide, place a minute quantity of beeswax
+  on two places at a distance apart nearly equal to the diameter of the cover used. Place a cover on
+  the wax and press it down flat, or sufficiently to keep it in position. Dip a fine needle into the
+  following cement:</p>
+
+  <table class="sp2 mc" title="Recipe for cement" summary="Recipe for cement">
+    <tr>
+      <td class="pr2">Glacial acetic acid</td>
+      <td>12 drachms</td>
+    </tr>
+    <tr>
+      <td>Gelatine</td>
+      <td><span class="hid">0</span>2 drachms</td>
+    </tr>
+    <tr>
+      <td>Alcohol</td>
+      <td><span class="hid">0</span>1 drachm</td>
+    </tr>
+  </table>
+
+  <p>This is made by adding the acid to the gelatine in a water-bath and then the alcohol, and
+  filtering. Apply the moistened needle to the centre of the cover and spread as small a quantity as
+  possible in a thin layer. Now place the slide upon the turn table, centre it with respect to the
+  position of the gelatine, and with the finest sable brush draw a circle about a tenth of an inch
+  in diameter around the gelatine in water-color (Windsor), blue or vermilion, or in India ink.
+  Instead of the water-color, a circle of tin-foil the size of the cover and pierced with a hole in
+  the centre may be used, but the colored circle is to be preferred, as, when brought into view, it
+  indicates exactly the focus required for observing the diatom.</p>
+
+  <p>The bottle containing the cleaned material, which has been kept in water and alcohol, should be
+  refilled with distilled water and well shaken, when a small portion may be taken up with a dipping
+  tube and evenly distributed over a portion of a slide and then dried. By the use of a mechanical
+  finger, fitted with a small piece of finely spun glass attached by wax to the holder of the
+  finger, when the microscope is focussed until the glass thread touches the diatom selected, it
+  will adhere to the thread. Raise the body of the microscope, remove the slide containing the
+  spread material, or move it to another part of the stage, and place the slide with the prepared
+  cover in the same position. Now carefully lower the body-tube of the instrument until the diatom
+  rests upon the gelatine, breathe gently upon it, remove the cover from the slide, invert it over
+  another slide containing a drop of styrax and proceed by heating to mount as before. The size of
+  the diatom, the amount of gelatine, and several other factors, will enter into the question of
+  success or failure. I have, however, employed the above method and have mounted thousands of
+  slides of selected diatoms successfully. It is necessary to avoid any air current which will cause
+  the diatom to fall from the thread. On very cold days the glass thread sometimes becomes
+  electrified and the diatoms will not stick; on sultry days in August in our locality the diatoms
+  will stick too closely.</p>
+
+  <p>By the same method, slides of arranged diatoms can be made using a glass circle properly marked
+  with lines in the eye-piece. Care should be taken to use glass threads more or less in proportion
+  to the size of the diatoms. A cat's whisker is preferred by some to the glass thread. It has the
+  advantage of not breaking, but unless it is quite short it is too flexible. If the point of the
+  thread becomes covered with gelatine, lower it into a minute drop of water upon a separate slide,
+  and by moving it about it will be cleaned. The diatom itself may be washed in the same way, if it
+  is not too small.</p>
+
+  <p><i>Instruments Required.</i>&mdash;For collecting, in order to determine the quality of the
+  find, any simple lens of fifteen to twenty diameters is sufficient. A Stanhope is quite useful
+  <span class="pagenum" id="page135">{135}</span>although difficult to obtain, while an achromatic
+  triplet of sufficient power will probably be all that is necessary. For selecting with the
+  mechanical finger, an objective of two-thirds-inch focus is the most convenient, but for
+  determining species a one-fifth-inch is needed, an immersion objective being essential for minute
+  forms.</p>
+
+  <p>No particular form of microscope is required. Any instrument having standard parts, inclination
+  of the body to the axis, a sub-stage condenser and movable stage, will prove serviceable in nearly
+  all investigations. For critical work, measurement of striæ and location of specimens on the
+  slide, the large models of Bausch and Lomb leave nothing to be desired. One smaller instrument may
+  be used for rapid examination and for selection with the mechanical finger. If the stage is
+  supplied with a vernier, the diatoms can be located rapidly and recorded for future reference. The
+  Zentmayer Army Hospital stand with mechanical stage is excellent. The Continental stands,
+  convenient for laboratory work, especially in the examination of bacteria, are not so serviceable
+  as the larger stands of American and English make. The stand especially designed by Dr. Henri Van
+  Heurck, the celebrated Belgian naturalist, is, without doubt, admirably suited to the
+  investigation of the Diatomaceæ. In the form of the Circuit Stage as made by Watson and Sons, of
+  London, supplied with proper condenser and mechanical stage with vernier attachment, it has been
+  used in the preparation of the present work with much satisfaction.</p>
+
+  <p class="sp5">The drawings have all been made with an Abbé camera lucida, a 3 mm. objective and a
+  No. 10 eye-piece, producing a magnification of about 800 diameters. All illustrations are from
+  actual specimens in my cabinet or, in a few instances, from slides sent me by friends. In the
+  measurement of striæ and puncta, the number in ten microns is stated, and will be found to be
+  approximately correct in most of the drawings, except when the number is in excess of twenty in
+  ten microns, in which case it is impossible to represent the markings accurately on figures of the
+  magnification adopted. All drawings are from specimens in this locality, except in a few cases
+  mentioned in the text.</p>
+
+  <div><span class="pagenum" id="page137">{137}</span></div>
+
+  <h1 class="sp3 ac" style="margin-bottom:2ex;"><span class="x-larger">INDEX</span></h1>
+
+  <p class="sp3 ac">(SYNONYMS IN ITALICS)</p>
+
+  <table class="sp5 mc wtf" title="Index" summary="Index">
+    <tr>
+      <td class="pl0 pt1"></td>
+      <td class="ar pt1"><span class="smaller">PAGE</span></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Achnanthes,</td>
+      <td class="ar pt1"><a href="#page58">58</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">brevipes Ag.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">coarctata (Bréb.) Grun.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">danica (Floegel) Grun.,</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">exigua Grun.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">inflata (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lanceolata (Bréb.) Grun.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">linearis forma curta H.L.S.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">longipes Ag.,</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">subsessilis Kuetz.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Actinella,</td>
+      <td class="ar pt1"><a href="#page54">54</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">punctata Lewis,</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Actinocyclus,</td>
+      <td class="ar pt1"><a href="#page26">26</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">barkleyi var. aggregata Rattr.,</td>
+      <td class="ar"><a href="#page27">27</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ellipticus var. delawarensis n. var.,</td>
+      <td class="ar"><a href="#page27">27</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">moniliformis Ralfs,</td>
+      <td class="ar"><a href="#page27">27</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Actinoptychus,</td>
+      <td class="ar pt1"><a href="#page24">24</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>cellulosa</i> Ehr.,</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">heliopelta Grun. var.?,</td>
+      <td class="ar"><a href="#page25">25</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>omphalopelta</i> Ehr.,</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">undulatus (Kuetz.) Ralfs,</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">vulgaris var. interrupta n. var.,</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Amphipleura,</td>
+      <td class="ar pt1"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pellucida Kuetz.,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">rutilans (Trentepohl) Cl.,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Amphiprora,</td>
+      <td class="ar pt1"><a href="#page68">68</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">alata Kuetz.,</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">conspicua Grev.,</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>lepidoptera</i> Greg.,</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ornata Bail.,</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">paludosa Wm. Sm.,</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pulchra Bail.,</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Amphitetras</i>,</td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>antediluviana</i> Ehr.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>tessellata</i> Shad.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Amphora,</td>
+      <td class="ar pt1"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acuta Greg.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">angusta var. eulensteinii Grun.,</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>aponina</i> Kuetz.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">arenaria Donk.,</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">areolata Grun.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">coffæiformis (Ag.) Kuetz.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">crassa Greg.,</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>eulensteinii</i> A.S.,</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gigantea var. fusca A.S.,</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>insecta</i> Grun.,</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lævis Greg.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lineolata Ehr.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>mucronata</i> H.L.S.,</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">obtusa Greg.,</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ocellata var. cingulata Cl.,</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ostrearia Bréb.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ovalis (Bréb.) Kuetz.,</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. libyca (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. pediculus (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>plicata</i> Greg.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>porcellus</i> Kitton,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">proteus Greg.,</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>quadrata</i> Bréb.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">robusta Greg.,</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>salina</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>vitræa</i> Cl.,</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Anom&#x0153;oneis,</td>
+      <td class="ar pt1"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">follis (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">serians Bréb.,</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sphærophora (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Anorthoneis,</td>
+      <td class="ar pt1"><a href="#page56">56</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">excentrica (Donk.) Grun.,</td>
+      <td class="ar"><a href="#page56">56</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Asterionella,</td>
+      <td class="ar pt1"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">formosa Hass.,</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">inflata Heib.,</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Attheya,</td>
+      <td class="ar pt1"><a href="#page38">38</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">decora West,</td>
+      <td class="ar"><a href="#page38">38</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Aulacodiscus,</td>
+      <td class="ar pt1"><a href="#page26">26</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">argus (Ehr.) A.S.,</td>
+      <td class="ar"><a href="#page26">26</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Auliscus,</td>
+      <td class="ar pt1"><a href="#page28">28</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cælatus Bail.,</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pruinosus Bail.,</td>
+      <td class="ar"><a href="#page28">28</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">punctatus Bail.,</td>
+      <td class="ar"><a href="#page28">28</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sculptus (Wm. Sm.) Ralfs,</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>spinosus</i> Christian,</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Auricula,</td>
+      <td class="ar pt1"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>insecta</i> (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">mucronata (H.L.S.) Per.,</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Bacillaria</i>,</td>
+      <td class="ar pt1"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>paradoxa</i> Gmelin,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Biddulphia,</td>
+      <td class="ar pt1"><a href="#page31">31</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">alternans (Bail.) V. H.,</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">antediluviana (Ehr.) V. H.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">biddulphiana (Smith),</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">favus (Ehr.) V. H.,</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">granulata Roper,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lævis Ehr.,</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>pulchella</i> Gray.,</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">reticulum (Ehr.),</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">rhombus (Ehr.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">smithii (Ralfs) V. H.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">turgida (Ehr.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Brébissonia,</td>
+      <td class="ar pt1"><a href="#page79">79</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">b&#x0153;ckii (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page79">79</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">palmerii n. sp.,</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">
+        <p class="sp0">Caloneis,</p>
+      </td>
+      <td class="ar pt1"><a href="#page81">81</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">brevis var. vexans Grun.,</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">formosa (Greg.) Cl.,</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">liber (Wm. Sm.) Cl.,</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">permagna (Bail.) Cl.,</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. lewisiana n. var.,</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">powellii (Lewis) Cl.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">silicula (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. inflata (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">trinodis (Lewis),</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">wardii Cl.,</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Campylodiscus,</td>
+      <td class="ar pt1"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>argus</i> Bail.,</td>
+      <td class="ar"><a href="#page130">130</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">echeneis Ehr.,</td>
+      <td class="ar"><a href="#page130">130</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">hibernicus Ehr.,</td>
+      <td class="ar"><a href="#page130">130</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Cerataulus</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>smithii</i> Ralfs,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>turgidus</i> Ehr.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Cocconeis,</td>
+      <td class="ar pt1"><a href="#page57">57</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">dirupta Greg.,</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pediculus Ehr.,</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pellucida Grun.,</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">placentula Ehr.,</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. lineata (Ehr.) V. H.,</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">scutellum Ehr.,</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. ornata Grun.,</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Cocconema</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>asperum</i> Ehr.,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Colletonema</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>neglectum</i> Thwaites,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>vulgaris</i> Thwaites,</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Conferva</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>biddulphiana</i> Smith,</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>flocculosa</i> Roth,</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>moniliformis</i> Mueller,</td>
+      <td class="ar"><a href="#page16">16</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>nummuloides</i> Dillw.,</td>
+      <td class="wnw ar"><a href="#page16">16</a>, <a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>rutilans</i> Trentepohl,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Coscinodiscus,</td>
+      <td class="ar pt1"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">argus Ehr.,</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">asteromphalus Ehr.,</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. omphalantha Grun.,</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">biangulatus A. S.,</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">denarius A. S.,</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">excentricus Ehr.,</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. perpusilla Grun.,</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lewisianus Grev.,</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lineatus Ehr.,</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">marginatus Ehr.,</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>minor</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page14">14</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">nitidulus Grun.,</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">nitidus Greg.,</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">oculus-iridus Ehr.,</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">polyacanthus Grun.,</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">radiatus Ehr.,</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>striatus</i> Kuetz.,</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">subaulacodiscoidalis Rattr.,</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">subtilis Ehr.,</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">velatus Ehr.,</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Creswellia</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>turris</i> Grev.,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Cyclotella,</td>
+      <td class="ar pt1"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">antiqua Wm. Sm.,</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">comta (Ehr.) Kuetz.,</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>dallasiana</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>kuetzingiana</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">meneghiniana Kuetz.,</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. stelligera Cl. and Grun.,</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. stellulifera Cl. and Grun.,</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">operculata (Ag.) Kuetz.,</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>scotica</i> Kuetz.,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">striata (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">stylorum (Br.?) V. H.,</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Cymatopleura,</td>
+      <td class="ar pt1"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">elliptica (Bréb.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">marina Lewis,</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">solea (Bréb.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Cymbella,</td>
+      <td class="ar pt1"><a href="#page60">60</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">affinis Kuetz.,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">amphicephala Nægeli,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">aspera (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cistula (Hempr.) Kirchn.,</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cuspidata Kuetz.,</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cymbiformis (Kuetz.) Bréb.,</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ehrenbergii Kuetz.,</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">excisa (Kuetz.) De Toni,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>gastroides</i> Kuetz.,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gracilis (Rab.) Cl.,</td>
+      <td class="ar"><a href="#page64">64</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">heteropleura (Ehr.) Kuetz.,</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lacustris (Ag.) Cl.,</td>
+      <td class="ar"><a href="#page64">64</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lanceolata (Ehr.) Kirchn.,</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">mexicana (Ehr.) A. S.,</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">naviculiformis Auerswald,</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">parva (Wm. Sm.) Cl.,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">philadelphica n. sp.,</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">prostrata (Berk.) Cl.,</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">rhomboidea n. sp.,</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sinuata Greg.,</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">triangulum (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tumida (Bréb.) V. H.,</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">turgida (Greg.) Cl.,</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var.?,</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ventricosa Kuetz.,</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Diatoma,</td>
+      <td class="ar pt1"><a href="#page41">41</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">anceps (Ehr.) Kirchn.,</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>arcuatum</i> Lyng.,</td>
+      <td class="ar"><a href="#page35">35</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>biddulphianum</i> Ag.,</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">hiemale (Lyng.) Heib.,</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>marinum</i> Lyng.,</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">vulgare Bory.,</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. elongatum (Ag.),</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. grande (Wm. Sm.) Grun.,</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Dictyoneis,</td>
+      <td class="ar pt1"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">marginata var. commutata Cl.,</td>
+      <td class="ar"><a href="#page79">79</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. maxima n. var.,</td>
+      <td class="ar"><a href="#page79">79</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. typica Cl.,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Dimerogramma,</td>
+      <td class="ar pt1"><a href="#page46">46</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">marinum (Greg.) Ralfs,</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">minus (Greg.) Ralfs,</td>
+      <td class="ar"><a href="#page47">47</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>sinuatum</i> Thwaites,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">surirella (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">
+        <p class="sp0">Diploneis,</p>
+      </td>
+      <td class="ar pt1"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">campylodiscus (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page86">86</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">crabro Ehr. var.?,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. expleta (A. S.) Cl.,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. pandura (Bréb.) Cl.,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. pandurella Cl.?,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">elliptica (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>minutissima</i> Grun.,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">excentrica n. sp.,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">fusca var. delicata (A. S.) Cl.,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gemmata (Grev.) Cl.,</td>
+      <td class="ar"><a href="#page86">86</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gruendleri (A. S.) Cl.,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">oculata (Bréb.) Cl.,</td>
+      <td class="ar"><a href="#page86">86</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">puella (Schum.) Cl.,</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">smithii (Bréb.) Cl.,</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Ditylum,</td>
+      <td class="ar pt1"><a href="#page30">30</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">intricatum (West) Grun.,</td>
+      <td class="ar"><a href="#page30">30</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Echinella</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>circularis</i> Grev.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>flabellata</i> Carm.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>paradoxa</i> Lyng.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Encyonema,</td>
+      <td class="ar pt1"><a href="#page62">62</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Epithemia,</td>
+      <td class="ar pt1"><a href="#page111">111</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">argus Kuetz.,</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var.?,</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>gibba</i> var. <i>ventricosa</i> Kuetz.,</td>
+      <td class="ar"><a href="#page113">113</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gibberula var. producta Grun.,</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>marina</i> Donk.,</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">muelleri A. S.?,</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">musculus Kuetz.,</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. constricta (Bréb.) V. H.,</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>succincta</i> Bréb.,</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">turgida (Ehr.) Kuetz.,</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">zebra var. proboscidea (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Eunotia,</td>
+      <td class="ar pt1"><a href="#page51">51</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">bactriana Ehr.,</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">biceps Ehr.,</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">bidentula Wm. Sm.,</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>bigibba</i> Greg.,</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">formica Ehr. var.?,</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gracilis (Ehr.) Rab.,</td>
+      <td class="ar"><a href="#page51">51</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">hemicyclus (Ehr.) Ralfs,</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>incisa</i> Greg.,</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">luna Ehr.,</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lunaris (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">major (Wm. Sm.) Rab.,</td>
+      <td class="ar"><a href="#page51">51</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">nymanniana Grun.,</td>
+      <td class="ar"><a href="#page51">51</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pectinalis (Kuetz.),</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. solierolii (Kuetz.),</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. undulata Ralfs,</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. ventricosa Grun.,</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">prærupta Ehr.,</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. bidens Grun.,</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">robusta Ralfs,</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">veneris Kuetz.,</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Eunotogramma,</td>
+      <td class="ar pt1"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">læve Grun.,</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Euodia,</td>
+      <td class="ar pt1"><a href="#page34">34</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gibba Bail.,</td>
+      <td class="ar"><a href="#page34">34</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Eupodiscus,</td>
+      <td class="ar pt1"><a href="#page28">28</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>argus</i> (Ehr.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page26">26</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">radiatus Bail.,</td>
+      <td class="ar"><a href="#page28">28</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>radiatus</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Fragilaria,</td>
+      <td class="ar pt1"><a href="#page44">44</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">arctica Grun.,</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">capucina var. mesolepta Rab.,</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">construens (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">harrisonii (Wm. Sm.) Grun.,</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">linearis Cstr.,</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">parasitica (Wm. Sm.),</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">undata Wm. Sm.,</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">virescens Ralfs,</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Frustulia,</td>
+      <td class="ar pt1"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>acuminata</i> Kuetz.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">interposita (Lewis) De Toni,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lewisiana (Grev.) De Toni,</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">rhomboides (Ehr.) De Toni,</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. amphipleuroides Grun.,</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. saxonica Rab.,</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">vulgaris (Thwaites) De Toni,</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Gaillonella,</td>
+      <td class="ar pt1"><a href="#page16">16</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>crenulata</i> Ehr.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>granulata</i> Ehr.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>moniliformis</i> Bail.,</td>
+      <td class="ar"><a href="#page16">16</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">nummuloides (Dillw.) Bory.,</td>
+      <td class="ar"><a href="#page16">16</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>sulcata</i> Ehr.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Gl&#x0153;onema</i>,</td>
+      <td class="ar pt1"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>triangulum</i> Ehr.,</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Gomphoneis,</td>
+      <td class="ar pt1"><a href="#page70">70</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">herculaneum (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page70">70</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">mamilla (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page70">70</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Gomphonema,</td>
+      <td class="ar pt1"><a href="#page70">70</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acuminatum,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. coronata (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. trigonocephala (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. turris (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. turris (Ehr.) Cl.?,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">æquale Greg.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">angustatum Kuetz.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">augur Ehr.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">brasiliense var. demeraræ Grun.?,</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">capitatum Ehr.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">capitatum var. herculaneum Ehr.,</td>
+      <td class="ar"><a href="#page70">70</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">constrictum Ehr.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">geminatum Lyng.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>insigne</i> Greg.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">intricatum Kuetz.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lanceolatum var. insignis (Greg.) Cl.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">montanum Schum.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">olivaceum Lyng.,</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">parvulum var. micropus (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sarcophagus Greg.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sphærophorum Ehr.,</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>subclavatum</i> var. <i>montana</i> Schum.,</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>tinctum</i> Ag.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ventricosum Greg.,</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Grammatophora,</td>
+      <td class="ar pt1"><a href="#page36">36</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">angulosa var. hamulifera (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">islandica Ehr.,</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">
+        <p class="sp0">marina (Lyng.) Kuetz.,</p>
+      </td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. subtilissima (Bail.) V. H.,</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">serpentina Ralfs,</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>subtilissima</i> Bail.,</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Gyrosigma,</td>
+      <td class="ar pt1"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acuminatum (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>attenuatum</i> (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">balticum (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>similis</i> (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">fasciola (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">hippocampus (Ehr.),</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">kuetzingii (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">parkeri var. stauroneioides Grun.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">prolongatum (Wm. Sm.) Cl.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">scalproides (Rab.) Cl.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">simile (Grun.),</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">spencerii var. nodifera Grun.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">strigilis (Wm. Sm.) Cl.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Hantzschia,</td>
+      <td class="ar pt1"><a href="#page113">113</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">amphioxys (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page113">113</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. major Grun.,</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">marina (Donk.) Grun.,</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">virgata (Roper) Grun.,</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Himantidium</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>pectinate</i> Kuetz.,</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Hom&#x0153;ocladia,</td>
+      <td class="ar pt1"><a href="#page123">123</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">filiformis Wm. Sm.,</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Hyalodiscus,</td>
+      <td class="ar pt1"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">radiatus var. arctica Grun.,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">scoticus (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">stelliger Bail.,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">subtilis Bail.,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Licmophora,</td>
+      <td class="ar pt1"><a href="#page38">38</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">baileyi (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ehrenbergii (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">flabellata (Carm.) Ag.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gracilis (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. elongata (Kuetz.) De Toni,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lyngbyei (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ovulum Mer.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">paradoxa (Lyng.) Ag.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>splendida</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tincta (Ag.) Grun.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Lysigonium,</td>
+      <td class="ar pt1"><a href="#page16">16</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">moniliforme (Muell.) Link,</td>
+      <td class="ar"><a href="#page16">16</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>nummuloides</i> (Lyng.) O'Meara,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">varians (Ag.) De Toni,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Mastogloia,</td>
+      <td class="ar pt1"><a href="#page86">86</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">angulata Lewis,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">apiculata Wm. Sm.,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>braunii</i> Grun.,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">elegans Lewis,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">exigua Lewis,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">kinsmanii Lewis,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lanceolata Thwaites,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">smithii Thwaites,</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Meloseira,</td>
+      <td class="ar pt1"><a href="#page14">14</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>borreri</i> Grev.,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">crenulata (Ehr.) Kuetz.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">distans (Ehr.) Kuetz.,</td>
+      <td class="ar"><a href="#page14">14</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>gowenii</i> A. S.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">granulata (Ehr.) Ralfs,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>nivalis</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page14">14</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>nummuloides</i> Ag.,</td>
+      <td class="ar"><a href="#page16">16</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">roeseana Rab.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. epidendron (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sulcata Kuetz.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">undulata (Ehr.) Kuetz.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>varians</i> Ag.,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Meridion,</td>
+      <td class="ar pt1"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">circulare (Grev.) Ag.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>constrictum</i> Ralfs,</td>
+      <td class="ar"><a href="#page41">41</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Micromega</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>ramosissimum</i> Ag.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Navicula,</td>
+      <td class="ar pt1"><a href="#page89">89</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>affinis</i> Ehr.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">americana Ehr.,</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>amphibola</i> Cl.,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>amphigomphus</i> Ehr.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">anglica Ralfs,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>angulata</i> Quek.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ardua Mann,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>arenaria</i> Donk.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">atomus Nægeli,</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">bacillum Ehr.,</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>baltica</i> Ehr.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">brasiliensis var. bicuneata Cl., forma constricta,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">crucigera (Wm. Sm.) Cl.,</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cryptocephala Kuetz.,</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cuspidata Kuetz.,</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. ambigua (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cyprinus (Wm. Sm.),</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">delawarensis Grun.,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">dicephala Wm. Sm.,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>digito-radiata</i> var. <i>cyprinus</i> (Ehr.?) Wm. Sm.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">elegans Wm. Sm.,</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. cuspidata Cl.,</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>firma</i> Kuetz.,</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>fischeri</i> A. S.,</td>
+      <td class="ar"><a href="#page90">90</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>follis</i> Ehr.,</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">fuchsii Pant.,</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gastrum Ehr.,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>gigas</i> A. S.,</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>globiceps</i> Lagerstedt,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gracilis var. schizonemoides (Ehr.) V. H.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">grevillei (Ag.) Cl.,</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">hasta Pant.,</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. punctata n. var.,</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">hennedyi Wm. Sm.,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. circumsecta Grun.,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. manta A. S.,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>hippocampus</i> Ehr.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>hitchcockii</i> Ehr.,</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">humerosa Bréb.,</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>elongata</i> Pant.,</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>fuchsii</i> (Pant.) Cl.,</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">
+        <p class="sp0">humilis Donk.,</p>
+      </td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>hungarica</i> var. <i>capitata</i> (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">inflexa Greg.,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">integra Wm. Sm.,</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>interposita</i> Lewis,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>iridis</i> Ehr.,</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">irrorata Grev.,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lacustris Greg.,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lanceolata var. arenaria (Donk.) Cl.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">latissima Greg.,</td>
+      <td class="ar"><a href="#page90">90</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. elongata (Pant.) Cl.,</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">libellus Greg.,</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>limosa</i> Donk.,</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">longa (Greg.) Ralfs,</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lyra Ehr.,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. dilatata A. S.,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. ehrenbergii Cl.,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var.?,</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">maculata (Bail.) Cl.,</td>
+      <td class="ar"><a href="#page90">90</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>marginata</i> Lewis,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>marina</i> Ralfs,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">minima Grun.,</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>mormonorum</i> Grun.,</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">mutica Kuetz.,</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">oblonga Kuetz.,</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>oculata</i> Bréb.,</td>
+      <td class="ar"><a href="#page86">86</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">palpebralis Bréb.,</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pennata A. S.,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">peregrina Ehr.,</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pinnata Pant.?,</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">placenta Ehr.,</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">prætexta Ehr.,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>producta</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">punctata var. asymmetrica Lagerstedt,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">punctulata Wm. Sm.,</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pupula var. bacillarioides Grun.,</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pusilla Wm. Sm.,</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. subcapitata n. var.,</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pygmæa Kuetz.,</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">radiosa Kuetz.,</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ramosissima (Ag.) Cl.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>rectangulata</i> Greg.,</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">reinhardtii Grun.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">rhyncocephala Kuetz.,</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">salinarum Grun.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">semen Ehr.,</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>silicula</i> Ehr.,</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>socialis</i> Palmer,</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">spectabilis var. emarginata Cl.,</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>sphærophora</i> Kuetz.,</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">spicula (Hickie) Cl.,</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>trochus</i> Kuetz.,</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tumida (Bréb.) Cl.,</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">viridula var. rostellata Kuetz.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">yarrensis Grun.,</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Neidium,</td>
+      <td class="ar pt1"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">affine (Ehr.) Pfitzer,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. amphirhyncus (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. genuina forma maxima Cl.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. genuina forma minor Cl.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">amphigomphus (Ehr.) Pfitzer,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">hitchcockii (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">iridis (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">productum (Wm. Sm.) Cl.,</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Nitzschia,</td>
+      <td class="ar pt1"><a href="#page114">114</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acicularis (Kuetz.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acuminata (Wm. Sm.) Grun.,</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">amphibis Grun.,</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">amphioxys Wm. Sm.,</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">apiculata (Greg.) Grun.,</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">bilobata Wm. Sm.,</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">circumsuta (Bail.) Grun.,</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">clausii Hantzsch,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">communis Rab.,</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">compressa Bail.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. minor H. L. S.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>curvula</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">dissipata (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">dubia Wm. Sm.,</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">epithemioides Grun.,</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">fluminensis Grun.,</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">granulata Grun.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">insignis Greg.,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">intermedia Hantzsch,</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">linearis (Ag.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">litoralis var. delawarensis Grun.,</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">longissima (Bréb.) Ralfs,</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">forma parva V. H.,</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">macilenta Greg.,</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">navicularis (Bréb.) Grun.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">obtusa Wm. Sm.,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. flexella H. L. S.,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. scalpelliformis Grun.,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">palea (Kuetz.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">panduriformis Greg.,</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. minor Grun.,</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>paradoxa</i> (Gmelin) Grun.,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">paxillifer (O. F. Mueller) Heib.,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">plana Wm. Sm.,</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>punctata</i> (Wm. Sm.) Grun.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">reversa Wm. Sm.,</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">scalaris (Ehr.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sigma (Kuetz.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>curvula</i> (Wm. Sm.) De Toni,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">sigmatella Greg.,</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>sinuata</i> var. <i>tabellaria</i> (Grun.) V. H.,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">spathulata Bréb.,</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">spectabilis var. americana Grun.,</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tabellaria Grun.,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tryblionella Hantzsch,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">vermicularis (Kuetz.) Hantzsch,</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Odontidium</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>parasiticum</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>tabellaria</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Opephora,</td>
+      <td class="ar pt1"><a href="#page43">43</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pacifica (Grun.) Petit,</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pinnata var. lanceolata n. var.,</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">schwartzii (Grun.) Petit,</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">
+        <p class="sp0"><i>Orthosira</i></p>
+      </td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>orichalcea</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>punctata</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>spinosa</i> Grev.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Paralia</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>marina</i> Heib.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>sulcata</i> (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Pinnularia,</td>
+      <td class="ar pt1"><a href="#page101">101</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acrosphæria (Bréb.) Cl.,</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. turgidula Grun.?,</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">æstuarii Cl.,</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">appendiculata (Ag.) Cl.,</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">blandita n. sp.,</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">borealis Ehr.,</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. scalaris (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">braunii Grun.,</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">brébissonii (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cardinaliculus Cl.,</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>cyprinus</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">dactylus Ehr.,</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. dariana (A. S.) Cl.,</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. demeraræ Cl.,</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">divergens var. elliptica Grun.,</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gentilis (Donk.) Cl.,</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gibba (Kuetz.) V. H.,</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>interrupta</i> forma <i>stauroneiformis</i> Cl.,</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lata (Bréb.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">legumen Ehr.,</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var.?,</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">leptosoma Grun.,</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">major (Kuetz.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page102">102</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. pulchella n. var.,</td>
+      <td class="ar"><a href="#page102">102</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">mesogongyla (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">mesolepta Ehr.,</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. stauroneiformis Grun.,</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">microstauron (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">molaris (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">mormonorum Grun.,</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">nobilis Ehr.,</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">nodosa forma capitata Cl.,</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">parva (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>permagna</i> Bail.,</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">polyonca (Bréb.) Lewis,</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">rectangulata (Greg.) Cl.,</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">socialis (Palmer),</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">stauroptera (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. interrupta forma stauroneiformis Cl.,</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">stomatophora (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">subcapitata Greg.,</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. paucistriata Grun.,</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tabellaria (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">termes (Ehr.) A. S.,</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. stauroneiformis V. H.,</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">trigonocephala Cl.,</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">viridis Nitzsch,</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. caudata n. var.,</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. fallax Cl.,</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var.?,</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Plagiogramma,</td>
+      <td class="ar pt1"><a href="#page42">42</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">obesum Grev.,</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pygmæum Grev.,</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tessellatum Grev.,</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">wallichianum Grev.,</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Pleurosigma,</td>
+      <td class="ar pt1"><a href="#page73">73</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">æstuarii Bréb.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>affine</i> var. <i>fossilis</i> Grun.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">angulatum (Quekett) Cl.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>balticum</i> (Ehr.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">formosum Wm. Sm.,</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>hippocampus</i> (Ehr.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">naviculaceum Bréb.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>normanii</i> var. <i>fossilis</i> Grun.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">obscurum Wm. Sm.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">rigidum Wm. Sm.,</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>simile</i> Grun.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>spencerii</i> var. <i>acutiuscula</i> Grun.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>kuetzingii</i> Grun.,</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">strigosum Wm. Sm.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">virginiacum H. L. S.,</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Podocystis,</td>
+      <td class="ar pt1"><a href="#page128">128</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">adriatica Kuetz.,</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>americana</i> Bail.,</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Podosira</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>hormoides</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>maculata</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Podosphenia</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>baileyi</i> (Edw.) Lewis,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>ehrenbergii</i> Kuetz.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>lyngbyei</i> Kuetz.,</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Polymyxus,</td>
+      <td class="ar pt1"><a href="#page25">25</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">coronalis L. W. Bail.,</td>
+      <td class="ar"><a href="#page25">25</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Pseudauliscus,</td>
+      <td class="ar pt1"><a href="#page29">29</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">radiatus (Bail.) Rattr.,</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">spinosus (Christian) Rattr.,</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Pyxidicula,</td>
+      <td class="ar pt1"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>compressa</i> Bail.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>minor</i> H. L. S.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cruciata Ehr.,</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>radiata</i> O'Meara,</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Rhabdonema,</td>
+      <td class="ar pt1"><a href="#page35">35</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">adriaticum Kuetz.,</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">arcuatum (Lyng.) Kuetz.,</td>
+      <td class="ar"><a href="#page35">35</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">minutum Kuetz.,</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Rhaphoneis,</td>
+      <td class="ar pt1"><a href="#page46">46</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">amphiceros Ehr.,</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. rhombica Grun.,</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">belgica var. intermedia Grun.,</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Rhipidophora</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>elongata</i> Kuetz.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>paradoxa</i> Kuetz.,</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Rhoicosphenia,</td>
+      <td class="ar pt1"><a href="#page56">56</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">curvata (Kuetz.) Grun.,</td>
+      <td class="ar"><a href="#page56">56</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Rhopalodia,</td>
+      <td class="ar pt1"><a href="#page112">112</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gibba (Kuetz.) Mueller,</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ventricosa (Kuetz.) Mueller,</td>
+      <td class="ar"><a href="#page113">113</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Schizonema</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>cruciger</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>dillwynii</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">
+        <p class="sp0"><i>grevillei</i> Ag.,</p>
+      </td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>smithii</i> Kuetz.,</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Scoliopleura</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>tumida</i> (Bréb.) V. H.,</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Scoliotropis,</td>
+      <td class="ar pt1"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">latestriata var. amphora Cl.,</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Stauroneis,</td>
+      <td class="ar pt1"><a href="#page88">88</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acuta Wm. Sm.,</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">americana A. S.,</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">anceps Ehr.,</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. amphicephala (Kuetz.) Cl.,</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. gracilis (Ehr.) Cl.,</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">crucicula (Grun.) Cl.,</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>exilis</i> Kuetz.,</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">frickei var. angusta n. var.,</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">legumen Ehr.,</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>maculata</i> Bail.,</td>
+      <td class="ar"><a href="#page90">90</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ph&#x0153;nicenteron Ehr.,</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">salina Wm. Sm.,</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">smithii Grun.,</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>spicula</i> Hickie,</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Staurosira</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>construens</i> Ehr.,</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Stephanopyxis,</td>
+      <td class="ar pt1"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>appendiculata</i> Ehr.,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">corona (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">turris (Grev.) Ralfs,</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Striatella,</td>
+      <td class="ar pt1"><a href="#page37">37</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">interrupta (Ehr.) Heib.,</td>
+      <td class="ar"><a href="#page38">38</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">unipunctata (Lyng.) Ag.,</td>
+      <td class="ar"><a href="#page38">38</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Surirella,</td>
+      <td class="ar pt1"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">amphioxys Wm. Sm.,</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">anceps Lewis,</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">angusta Kuetz.,</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">arctissima A. S.,</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>bifrons</i> Ehr.,</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">biseriata (Ehr.) Bréb.,</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>cardinalis</i> Kitton,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>circumsuta</i> Bail.,</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">cruciata A. S.,</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">crumena Bréb.,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>davidsonii</i> A. S.,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">delicatissima Lewis,</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>diaphana</i> Bleisch,</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">elegans Ehr.,</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">fastuosa Ehr.,</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">febigerii Lewis,</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gemma Ehr.,</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">gracilis Grun.,</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">guatimalensis Ehr.,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">intermedia Lewis,</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">linearis Wm. Sm.,</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>m&#x0153;lleriana</i> Grun.,</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">oblonga Ehr.?,</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ovalis Bréb.,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. <i>pinnata</i> (Wm. Sm.) De Toni,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">panduriformis Wm. Sm.,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pinnata Wm. Sm.,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. minuta Grun.,</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">recedens A. S.,</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">robusta Ehr.,</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">splendida (Ehr.) Kuetz.,</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">striatula Turpin,</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">tenera Greg.,</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Synedra,</td>
+      <td class="ar pt1"><a href="#page47">47</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">acus Kuetz.,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">affinis Kuetz.,</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. parva (Kuetz.) V. H.,</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. tabulata (Ag.) V. H.,</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">biceps (Kuetz.) A. S.,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">capitata Ehr.,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">danica Kuetz.,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">fulgens (Grev.) Wm. Sm.,</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">goulardi Bréb.,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>gracilis</i> Kuetz.,</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">oxyrhynchus var. undulata Grun.,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pulchella (Ralfs) Kuetz.,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. abnormis Macchiati?,</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td class="pl2">var. flexella n. var.,</td>
+      <td class="ar"><a href="#page49">49</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">radians Kuetz.,</td>
+      <td class="ar"><a href="#page49">49</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">ulna (Nitzsch) Ehr.,</td>
+      <td class="ar"><a href="#page47">47</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">vaucheriæ var. parvula (Kuetz.) Rab.,</td>
+      <td class="ar"><a href="#page49">49</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Tabellaria,</td>
+      <td class="ar pt1"><a href="#page36">36</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">fenestrata (Lyng.),</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">flocculosa (Roth) Kuetz.,</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Terpsinoë,</td>
+      <td class="ar pt1"><a href="#page34">34</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">americana (Bail.) Ralfs,</td>
+      <td class="ar"><a href="#page34">34</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">novæ-cæsareæ Boyer,</td>
+      <td class="ar"><a href="#page34">34</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Tessella</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>interrupta</i> Ehr.,</td>
+      <td class="ar"><a href="#page38">38</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Trachyneis,</td>
+      <td class="ar pt1"><a href="#page79">79</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">aspera var. intermedia Grun.,</td>
+      <td class="ar"><a href="#page79">79</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Trachysphenia,</td>
+      <td class="ar pt1"><a href="#page47">47</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">australis Petit,</td>
+      <td class="ar"><a href="#page47">47</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Triceratium</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>alternans</i> Bail.,</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>favus</i> Ehr.,</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>obtusum</i> Br.,</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>pileotus</i> Ehr.,</td>
+      <td class="ar"><a href="#page30">30</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>punctatum</i> Br.,</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>sculptum</i> Shad.,</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Trinacria,</td>
+      <td class="ar pt1"><a href="#page30">30</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">pileolus (Ehr.) Grun.,</td>
+      <td class="ar"><a href="#page30">30</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Tripodiscus</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>argus</i> Ehr.,</td>
+      <td class="ar"><a href="#page26">26</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1">Tropidoneis,</td>
+      <td class="ar pt1"><a href="#page68">68</a></td>
+    </tr>
+    <tr>
+      <td class="pl1">lepidoptera (Greg.) Cl.,</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Tryblionella</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>punctata</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>scutellum</i> Wm. Sm.,</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr>
+      <td class="pl0 pt1"><i>Vibrio</i></td>
+    </tr>
+    <tr>
+      <td class="pl1"><i>paxillifer</i> O. F. Mueller,</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+  </table>
+
+  <h1 class="sp3 ac" style="margin-bottom:2ex;"><span class="x-larger">PLATES</span></h1>
+
+  <div id="plate1"></div>
+
+  <h2>PLATE 1</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 1" summary="Plate 1">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">MELOSEIRA</td>
+          </tr>
+          <tr class="pb05">
+            <td>3-4</td>
+            <td>Meloseira roeseana var. epidendron (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page15">15</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5-6</td>
+            <td>Meloseira roeseana Rab.</td>
+            <td class="ar"><a href="#page15">15</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8-9</td>
+            <td>Meloseira distans (Ehr.) Kuetz.</td>
+            <td class="ar"><a href="#page14">14</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Meloseira granulata (Ehr.) Ralfs</td>
+            <td class="ar"><a href="#page15">15</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11-12</td>
+            <td>Meloseira sulcata Kuetz.</td>
+            <td class="ar"><a href="#page15">15</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15-16-17</td>
+            <td>Meloseira undulata (Ehr.) Kuetz.</td>
+            <td class="ar"><a href="#page15">15</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">GAILLONELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>13-14</td>
+            <td>Gaillonella nummuloides (Dillw.) Bory</td>
+            <td class="ar"><a href="#page16">16</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">LYSIGONIUM</td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Lysigonium moniliforme (Muell.) Link.</td>
+            <td class="ar"><a href="#page16">16</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18-19</td>
+            <td>Lysigonium varians (Ag.) De Toni</td>
+            <td class="ar"><a href="#page17">17</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">HYALODISCUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Hyalodiscus scoticus (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page18">18</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Hyalodiscus radiatus var. arctica Grun.</td>
+            <td class="ar"><a href="#page17">17</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Hyalodiscus stelliger Bail.</td>
+            <td class="ar"><a href="#page17">17</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05"><span class="sc">Note.</span>&mdash;The figures in all
+            of the plates, except when otherwise noted, are magnified 800 diameters.</td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate01.jpg"><img
+      style="width:100%" src="images/plate01.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 1" summary="Plate 1">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">MELOSEIRA</td>
+    </tr>
+    <tr class="pb05">
+      <td>3-4</td>
+      <td>Meloseira roeseana var. epidendron (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5-6</td>
+      <td>Meloseira roeseana Rab.</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8-9</td>
+      <td>Meloseira distans (Ehr.) Kuetz.</td>
+      <td class="ar"><a href="#page14">14</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Meloseira granulata (Ehr.) Ralfs</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11-12</td>
+      <td>Meloseira sulcata Kuetz.</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15-16-17</td>
+      <td>Meloseira undulata (Ehr.) Kuetz.</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">GAILLONELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>13-14</td>
+      <td>Gaillonella nummuloides (Dillw.) Bory</td>
+      <td class="ar"><a href="#page16">16</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">LYSIGONIUM</td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Lysigonium moniliforme (Muell.) Link.</td>
+      <td class="ar"><a href="#page16">16</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18-19</td>
+      <td>Lysigonium varians (Ag.) De Toni</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">HYALODISCUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Hyalodiscus scoticus (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Hyalodiscus radiatus var. arctica Grun.</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Hyalodiscus stelliger Bail.</td>
+      <td class="ar"><a href="#page17">17</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05"><span class="sc">Note.</span>&mdash;The figures in all of the
+      plates, except when otherwise noted, are magnified 800 diameters.</td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate01.jpg"><img
+      style="width:100%" src="images/plate01.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate2"></div>
+
+  <h2>PLATE 2</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 2" summary="Plate 2">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">STEPHANOPYXIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2</td>
+            <td>Stephanopyxis turris (Grev.) Ralfs</td>
+            <td class="ar"><a href="#page18">18</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Stephanopyxis corona (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page18">18</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">CYCLOTELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Cyclotella meneghiniana var. stelligera Cl. and Grun.</td>
+            <td class="ar"><a href="#page20">20</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5-6</td>
+            <td>Cyclotella operculata (Ag.) Kuetz.</td>
+            <td class="ar"><a href="#page20">20</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Cyclotella comta (Ehr.) Kuetz.</td>
+            <td class="ar"><a href="#page20">20</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Cyclotella meneghiniana Kuetz.</td>
+            <td class="ar"><a href="#page19">19</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Cyclotella striata (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page19">19</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Cyclotella stylorum (Br.?) V. H.</td>
+            <td class="ar"><a href="#page20">20</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Cyclotella antiqua Wm. Sm.</td>
+            <td class="ar"><a href="#page20">20</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Cyclotella meneghiniana var. stellulifera Cl. and Grun.</td>
+            <td class="ar"><a href="#page20">20</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">COSCINODISCUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Coscinodiscus denarius A. S.</td>
+            <td class="ar"><a href="#page22">22</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Coscinodiscus excentricus Ehr.</td>
+            <td class="ar"><a href="#page21">21</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15-17</td>
+            <td>Coscinodiscus subtilis Ehr.</td>
+            <td class="ar"><a href="#page21">21</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Coscinodiscus asteromphalus Ehr.</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Coscinodiscus nitidus Greg.</td>
+            <td class="ar"><a href="#page21">21</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19</td>
+            <td>Coscinodiscus nitidulus Grun.</td>
+            <td class="ar"><a href="#page21">21</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Coscinodiscus excentricus var. perpusilla Grun. ?</td>
+            <td class="ar"><a href="#page21">21</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate02.jpg"><img
+      style="width:100%" src="images/plate02.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 2" summary="Plate 2">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">STEPHANOPYXIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2</td>
+      <td>Stephanopyxis turris (Grev.) Ralfs</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Stephanopyxis corona (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page18">18</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">CYCLOTELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Cyclotella meneghiniana var. stelligera Cl. and Grun.</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5-6</td>
+      <td>Cyclotella operculata (Ag.) Kuetz.</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Cyclotella comta (Ehr.) Kuetz.</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Cyclotella meneghiniana Kuetz.</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Cyclotella striata (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Cyclotella stylorum (Br.?) V. H.</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Cyclotella antiqua Wm. Sm.</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Cyclotella meneghiniana var. stellulifera Cl. and Grun.</td>
+      <td class="ar"><a href="#page20">20</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">COSCINODISCUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Coscinodiscus denarius A. S.</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Coscinodiscus excentricus Ehr.</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15-17</td>
+      <td>Coscinodiscus subtilis Ehr.</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Coscinodiscus asteromphalus Ehr.</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Coscinodiscus nitidus Greg.</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19</td>
+      <td>Coscinodiscus nitidulus Grun.</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Coscinodiscus excentricus var. perpusilla Grun. ?</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate02.jpg"><img
+      style="width:100%" src="images/plate02.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate3"></div>
+
+  <h2>PLATE 3</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 3" summary="Plate 3">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">COSCINODISCUS&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-11</td>
+            <td>Coscinodiscus radiatus Ehr.</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Coscinodiscus velatus Ehr.</td>
+            <td class="ar"><a href="#page22">22</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Coscinodiscus biangulatus A. S.</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Coscinodiscus subaulacodiscoidalis Rattr.</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Coscinodiscus lewisianus Grev.</td>
+            <td class="ar"><a href="#page24">24</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Coscinodiscus argus Ehr.</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Coscinodiscus lineatus Ehr.</td>
+            <td class="ar"><a href="#page21">21</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Coscinodiscus marginatus Ehr.</td>
+            <td class="ar"><a href="#page22">22</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Coscinodiscus oculus-iridis Ehr.</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">ACTINOCYCLUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Actinocyclus ellipticus var. delawarensis n. var.</td>
+            <td class="ar"><a href="#page27">27</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate03.jpg"><img
+      style="width:100%" src="images/plate03.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 3" summary="Plate 3">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">COSCINODISCUS&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-11</td>
+      <td>Coscinodiscus radiatus Ehr.</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Coscinodiscus velatus Ehr.</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Coscinodiscus biangulatus A. S.</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Coscinodiscus subaulacodiscoidalis Rattr.</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Coscinodiscus lewisianus Grev.</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Coscinodiscus argus Ehr.</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Coscinodiscus lineatus Ehr.</td>
+      <td class="ar"><a href="#page21">21</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Coscinodiscus marginatus Ehr.</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Coscinodiscus oculus-iridis Ehr.</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">ACTINOCYCLUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Actinocyclus ellipticus var. delawarensis n. var.</td>
+      <td class="ar"><a href="#page27">27</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate03.jpg"><img
+      style="width:100%" src="images/plate03.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate4"></div>
+
+  <h2>PLATE 4</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 4" summary="Plate 4">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">ACTINOPTYCHUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-4-6</td>
+            <td>Actinoptychus undulatus (Kuetz.) Ralfs.</td>
+            <td class="ar"><a href="#page24">24</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Actinoptychus undulatus (inner stratum)</td>
+            <td class="ar"><a href="#page24">24</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Actinoptychus heliopelta Grun. var.?</td>
+            <td class="ar"><a href="#page25">25</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Actinoptychus vulgaris var. interrupta n. var.</td>
+            <td class="ar"><a href="#page24">24</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">POLYMYXUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Polymyxus coronalis L. W. Bail.</td>
+            <td class="ar"><a href="#page25">25</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">AULACODISCUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Aulacodiscus argus (Ehr.) A. S.</td>
+            <td class="ar"><a href="#page26">26</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate04.jpg"><img
+      style="width:100%" src="images/plate04.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 4" summary="Plate 4">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">ACTINOPTYCHUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-4-6</td>
+      <td>Actinoptychus undulatus (Kuetz.) Ralfs.</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Actinoptychus undulatus (inner stratum)</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Actinoptychus heliopelta Grun. var.?</td>
+      <td class="ar"><a href="#page25">25</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Actinoptychus vulgaris var. interrupta n. var.</td>
+      <td class="ar"><a href="#page24">24</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">POLYMYXUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Polymyxus coronalis L. W. Bail.</td>
+      <td class="ar"><a href="#page25">25</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">AULACODISCUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Aulacodiscus argus (Ehr.) A. S.</td>
+      <td class="ar"><a href="#page26">26</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate04.jpg"><img
+      style="width:100%" src="images/plate04.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate5"></div>
+
+  <h2>PLATE 5</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 5" summary="Plate 5">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">EUODIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Euodia gibba Bail.</td>
+            <td class="ar"><a href="#page34">34</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">POLYMYXUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Polymyxus coronalis L. W. Bail., zone view</td>
+            <td class="ar"><a href="#page25">25</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">EUPODISCUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Eupodiscus radiatus Bail.</td>
+            <td class="ar"><a href="#page28">28</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">AULISCUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Auliscus cælatus Bail.</td>
+            <td class="ar"><a href="#page29">29</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Auliscus sculptus (Wm. Sm.) Ralfs</td>
+            <td class="ar"><a href="#page29">29</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Auliscus punctatus Bail.</td>
+            <td class="ar"><a href="#page28">28</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Auliscus (intermediate form between A. cælatus and A. sculptus)</td>
+            <td class="ar"><a href="#page29">29</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Auliscus pruinosus Bail.</td>
+            <td class="ar"><a href="#page28">28</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">PSEUDAULISCUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Pseudauliscus radiatus (Bail.) Rattr.</td>
+            <td class="ar"><a href="#page29">29</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Pseudauliscus spinosus (Christian) Rattr.</td>
+            <td class="ar"><a href="#page29">29</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate05.jpg"><img
+      style="width:100%" src="images/plate05.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 5" summary="Plate 5">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">EUODIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Euodia gibba Bail.</td>
+      <td class="ar"><a href="#page34">34</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">POLYMYXUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Polymyxus coronalis L. W. Bail., zone view</td>
+      <td class="ar"><a href="#page25">25</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">EUPODISCUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Eupodiscus radiatus Bail.</td>
+      <td class="ar"><a href="#page28">28</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">AULISCUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Auliscus cælatus Bail.</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Auliscus sculptus (Wm. Sm.) Ralfs</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Auliscus punctatus Bail.</td>
+      <td class="ar"><a href="#page28">28</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Auliscus (intermediate form between A. cælatus and A. sculptus)</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Auliscus pruinosus Bail.</td>
+      <td class="ar"><a href="#page28">28</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">PSEUDAULISCUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Pseudauliscus radiatus (Bail.) Rattr.</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Pseudauliscus spinosus (Christian) Rattr.</td>
+      <td class="ar"><a href="#page29">29</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate05.jpg"><img
+      style="width:100%" src="images/plate05.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate6"></div>
+
+  <h2>PLATE 6</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 6" summary="Plate 6">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">ACTINOCYCLUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Actinocyclus barkleyi var. aggregata Rattr.</td>
+            <td class="ar"><a href="#page27">27</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Actinocyclus moniliformis Ralfs.</td>
+            <td class="ar"><a href="#page27">27</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">BIDDULPHIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Biddulphia antediluviana (Ehr.) V. H.</td>
+            <td class="ar"><a href="#page32">32</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Biddulphia reticulum (Ehr.)</td>
+            <td class="ar"><a href="#page33">33</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Biddulphia favus (Ehr.) V. H.</td>
+            <td class="ar"><a href="#page31">31</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7-8</td>
+            <td>Biddulphia alternans (Bail.) V. H.</td>
+            <td class="ar"><a href="#page33">33</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">TRINACRIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Trinacria pileolus (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page30">30</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">DITYLUM</td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Ditylum intricatum (West) Grun.</td>
+            <td class="ar"><a href="#page30">30</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">TERPSINOË</td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Terpsinoë americana (Bail.) Ralfs.</td>
+            <td class="ar"><a href="#page34">34</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Terpsinoë novæ-cæsareæ Boyer</td>
+            <td class="ar"><a href="#page34">34</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate06.jpg"><img
+      style="width:100%" src="images/plate06.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 6" summary="Plate 6">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">ACTINOCYCLUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Actinocyclus barkleyi var. aggregata Rattr.</td>
+      <td class="ar"><a href="#page27">27</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Actinocyclus moniliformis Ralfs.</td>
+      <td class="ar"><a href="#page27">27</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">BIDDULPHIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Biddulphia antediluviana (Ehr.) V. H.</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Biddulphia reticulum (Ehr.)</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Biddulphia favus (Ehr.) V. H.</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7-8</td>
+      <td>Biddulphia alternans (Bail.) V. H.</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">TRINACRIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Trinacria pileolus (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page30">30</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">DITYLUM</td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Ditylum intricatum (West) Grun.</td>
+      <td class="ar"><a href="#page30">30</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">TERPSINOË</td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Terpsinoë americana (Bail.) Ralfs.</td>
+      <td class="ar"><a href="#page34">34</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Terpsinoë novæ-cæsareæ Boyer</td>
+      <td class="ar"><a href="#page34">34</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate06.jpg"><img
+      style="width:100%" src="images/plate06.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate7"></div>
+
+  <h2>PLATE 7</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 7" summary="Plate 7">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">BIDDULPHIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2-3-4</td>
+            <td>Biddulphia biddulphiana (Smith)</td>
+            <td class="ar"><a href="#page31">31</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Biddulphia rhombus (Ehr.) Wm. Sm.</td>
+            <td class="ar"><a href="#page32">32</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Biddulphia granulata Roper</td>
+            <td class="ar"><a href="#page32">32</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Biddulphia turgida (Ehr.) Wm. Sm.</td>
+            <td class="ar"><a href="#page32">32</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Biddulphia smithii (Ralfs) V. H.</td>
+            <td class="ar"><a href="#page32">32</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Biddulphia lævis Ehr.</td>
+            <td class="ar"><a href="#page33">33</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Biddulphia lævis Ehr. Sporangial frustules (260 diam.)</td>
+            <td class="ar"><a href="#page33">33</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">EUNOTOGRAMMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Eunotogramma læve Grun.</td>
+            <td class="ar"><a href="#page33">33</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate07.jpg"><img
+      style="width:100%" src="images/plate07.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 7" summary="Plate 7">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">BIDDULPHIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2-3-4</td>
+      <td>Biddulphia biddulphiana (Smith)</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Biddulphia rhombus (Ehr.) Wm. Sm.</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Biddulphia granulata Roper</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Biddulphia turgida (Ehr.) Wm. Sm.</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Biddulphia smithii (Ralfs) V. H.</td>
+      <td class="ar"><a href="#page32">32</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Biddulphia lævis Ehr.</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Biddulphia lævis Ehr. Sporangial frustules (260 diam.)</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">EUNOTOGRAMMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Eunotogramma læve Grun.</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate07.jpg"><img
+      style="width:100%" src="images/plate07.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate8"></div>
+
+  <h2>PLATE 8</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 8" summary="Plate 8">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">RHABDONEMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2-3</td>
+            <td>Rhabdonema arcuatum (Lyng.) Kuetz.</td>
+            <td class="ar"><a href="#page35">35</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4-5-6</td>
+            <td>Rhabdonema adriaticum Kuetz.</td>
+            <td class="ar"><a href="#page36">36</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Rhabdonema minutum Kuetz.</td>
+            <td class="ar"><a href="#page36">36</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">TABELLARIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>8-9-10</td>
+            <td>Tabellaria flocculosa (Roth) Kuetz.</td>
+            <td class="ar"><a href="#page36">36</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11-12</td>
+            <td>Tabellaria fenestrata (Lyng.) Kuetz.</td>
+            <td class="ar"><a href="#page36">36</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">GRAMMATOPHORA</td>
+          </tr>
+          <tr class="pb05">
+            <td>13-14</td>
+            <td>Grammatophora marina var. subtilissima (Bail.) V. H.</td>
+            <td class="ar"><a href="#page37">37</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15-16</td>
+            <td>Grammatophora angulosa var. hamulifera (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page37">37</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17-18</td>
+            <td>Grammatophora marina (Lyng.) Kuetz.</td>
+            <td class="ar"><a href="#page37">37</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19-20</td>
+            <td>Grammatophora islandica Ehr.</td>
+            <td class="ar"><a href="#page37">37</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Grammatophora serpentina Ralfs.</td>
+            <td class="ar"><a href="#page37">37</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">STRIATELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>22-23</td>
+            <td>Striatella unipunctata (Lyng.) Ag.</td>
+            <td class="ar"><a href="#page38">38</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Striatella interrupta (Ehr.) Heib.</td>
+            <td class="ar"><a href="#page38">38</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">ATTHEYA</td>
+          </tr>
+          <tr class="pb05">
+            <td>25</td>
+            <td>Attheya decora West</td>
+            <td class="ar"><a href="#page38">38</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate08.jpg"><img
+      style="width:100%" src="images/plate08.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 8" summary="Plate 8">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">RHABDONEMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2-3</td>
+      <td>Rhabdonema arcuatum (Lyng.) Kuetz.</td>
+      <td class="ar"><a href="#page35">35</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4-5-6</td>
+      <td>Rhabdonema adriaticum Kuetz.</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Rhabdonema minutum Kuetz.</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">TABELLARIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>8-9-10</td>
+      <td>Tabellaria flocculosa (Roth) Kuetz.</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11-12</td>
+      <td>Tabellaria fenestrata (Lyng.) Kuetz.</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">GRAMMATOPHORA</td>
+    </tr>
+    <tr class="pb05">
+      <td>13-14</td>
+      <td>Grammatophora marina var. subtilissima (Bail.) V. H.</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15-16</td>
+      <td>Grammatophora angulosa var. hamulifera (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17-18</td>
+      <td>Grammatophora marina (Lyng.) Kuetz.</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19-20</td>
+      <td>Grammatophora islandica Ehr.</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Grammatophora serpentina Ralfs.</td>
+      <td class="ar"><a href="#page37">37</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">STRIATELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>22-23</td>
+      <td>Striatella unipunctata (Lyng.) Ag.</td>
+      <td class="ar"><a href="#page38">38</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Striatella interrupta (Ehr.) Heib.</td>
+      <td class="ar"><a href="#page38">38</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">ATTHEYA</td>
+    </tr>
+    <tr class="pb05">
+      <td>25</td>
+      <td>Attheya decora West</td>
+      <td class="ar"><a href="#page38">38</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate08.jpg"><img
+      style="width:100%" src="images/plate08.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate9"></div>
+
+  <h2>PLATE 9</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 9" summary="Plate 9">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">LICMOPHORA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2</td>
+            <td>Licmophora flabellata (Carm.) Ag.</td>
+            <td class="ar"><a href="#page39">39</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3-4</td>
+            <td>Licmophora lyngbyei Kuetz.</td>
+            <td class="ar"><a href="#page40">40</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Licmophora ehrenbergii (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page40">40</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6-7</td>
+            <td>Licmophora paradoxa (Lyng.) Ag.</td>
+            <td class="ar"><a href="#page39">39</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8-9</td>
+            <td>Licmophora ovulum Mer.</td>
+            <td class="ar"><a href="#page39">39</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Licmophora baileyi (Edw.) Grun.</td>
+            <td class="ar"><a href="#page40">40</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Licmophora gracilis (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page39">39</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12-13</td>
+            <td>Licmophora gracilis var. elongata (Kuetz.) De Toni</td>
+            <td class="ar"><a href="#page39">39</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14-15</td>
+            <td>Licmophora tincta (Ag.) Grun.</td>
+            <td class="ar"><a href="#page40">40</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate09.jpg"><img
+      style="width:100%" src="images/plate09.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 9" summary="Plate 9">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">LICMOPHORA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2</td>
+      <td>Licmophora flabellata (Carm.) Ag.</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3-4</td>
+      <td>Licmophora lyngbyei Kuetz.</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Licmophora ehrenbergii (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6-7</td>
+      <td>Licmophora paradoxa (Lyng.) Ag.</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8-9</td>
+      <td>Licmophora ovulum Mer.</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Licmophora baileyi (Edw.) Grun.</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Licmophora gracilis (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12-13</td>
+      <td>Licmophora gracilis var. elongata (Kuetz.) De Toni</td>
+      <td class="ar"><a href="#page39">39</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14-15</td>
+      <td>Licmophora tincta (Ag.) Grun.</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate09.jpg"><img
+      style="width:100%" src="images/plate09.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate10"></div>
+
+  <h2>PLATE 10</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 10" summary="Plate 10">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">MERIDION</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2-3</td>
+            <td>Meridion circulare (Grev.) Ag.</td>
+            <td class="ar"><a href="#page40">40</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">DIATOMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Diatoma vulgare var. grande (Wm. Sm.) Grun.</td>
+            <td class="ar"><a href="#page42">42</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5-6</td>
+            <td>Diatoma anceps (Ehr.) Kirchn.</td>
+            <td class="ar"><a href="#page42">42</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7-8</td>
+            <td>Diatoma hiemale (Lyng.) Heib.</td>
+            <td class="ar"><a href="#page42">42</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9-10</td>
+            <td>Diatoma vulgare Bory.</td>
+            <td class="ar"><a href="#page42">42</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">PLAGIOGRAMMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Plagiogramma tessellatum Grev.</td>
+            <td class="ar"><a href="#page43">43</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Plagiogramma obesum Grev.</td>
+            <td class="ar"><a href="#page43">43</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Plagiogramma pygmæum Grev.</td>
+            <td class="ar"><a href="#page43">43</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Plagiogramma wallichianum Grev.</td>
+            <td class="ar"><a href="#page43">43</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">EUNOTOGRAMMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Eunotogramma læve Grun.</td>
+            <td class="ar"><a href="#page33">33</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">OPEPHORA</td>
+          </tr>
+          <tr class="pb05">
+            <td>16-19</td>
+            <td>Opephora schwartzii (Grun.) Petit.</td>
+            <td class="ar"><a href="#page43">43</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Opephora pinnata var. lanceolata n. var.</td>
+            <td class="ar"><a href="#page44">44</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Opephora pacifica (Grun.) Petit.</td>
+            <td class="ar"><a href="#page43">43</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">FRAGILARIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>20-21</td>
+            <td>Fragilaria virescens Ralfs.</td>
+            <td class="ar"><a href="#page44">44</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22-23</td>
+            <td>Fragilaria arctica Grun.</td>
+            <td class="ar"><a href="#page44">44</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24-25-27-28-29</td>
+            <td>Fragilaria undata Wm. Sm.</td>
+            <td class="ar"><a href="#page44">44</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>26</td>
+            <td>Fragilaria undata Wm. Sm., var.?</td>
+            <td class="ar"><a href="#page44">44</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>30</td>
+            <td>Fragilaria construens (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page45">45</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>31</td>
+            <td>Fragilaria harrisonii (Wm. Sm.) Grun.</td>
+            <td class="ar"><a href="#page45">45</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>34</td>
+            <td>Fragilaria capucina var. mesolepta Rab.</td>
+            <td class="ar"><a href="#page45">45</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>35</td>
+            <td>Fragilaria parasitica (Wm. Sm.)</td>
+            <td class="ar"><a href="#page45">45</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>36</td>
+            <td>Fragilaria sp. ?</td>
+            <td class="ar"><a href="#page45">45</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>37</td>
+            <td>Fragilaria linearis Cstr.</td>
+            <td class="ar"><a href="#page45">45</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">RHAPHONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>38</td>
+            <td>Rhaphoneis amphiceros Ehr.</td>
+            <td class="ar"><a href="#page46">46</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>39-40</td>
+            <td>Rhaphoneis amphiceros var. rhombica Grun.</td>
+            <td class="ar"><a href="#page46">46</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>41</td>
+            <td>Rhaphoneis belgica var. intermedia Grun.</td>
+            <td class="ar"><a href="#page46">46</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">SYNEDRA</td>
+          </tr>
+          <tr class="pb05">
+            <td>32-33</td>
+            <td>Synedra radians Kuetz.</td>
+            <td class="ar"><a href="#page49">49</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate10.jpg"><img
+      style="width:100%" src="images/plate10.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 10" summary="Plate 10">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">MERIDION</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2-3</td>
+      <td>Meridion circulare (Grev.) Ag.</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">DIATOMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Diatoma vulgare var. grande (Wm. Sm.) Grun.</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5-6</td>
+      <td>Diatoma anceps (Ehr.) Kirchn.</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7-8</td>
+      <td>Diatoma hiemale (Lyng.) Heib.</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9-10</td>
+      <td>Diatoma vulgare Bory.</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">PLAGIOGRAMMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Plagiogramma tessellatum Grev.</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Plagiogramma obesum Grev.</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Plagiogramma pygmæum Grev.</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Plagiogramma wallichianum Grev.</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">EUNOTOGRAMMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Eunotogramma læve Grun.</td>
+      <td class="ar"><a href="#page33">33</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">OPEPHORA</td>
+    </tr>
+    <tr class="pb05">
+      <td>16-19</td>
+      <td>Opephora schwartzii (Grun.) Petit.</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Opephora pinnata var. lanceolata n. var.</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Opephora pacifica (Grun.) Petit.</td>
+      <td class="ar"><a href="#page43">43</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">FRAGILARIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>20-21</td>
+      <td>Fragilaria virescens Ralfs.</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22-23</td>
+      <td>Fragilaria arctica Grun.</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24-25-27-28-29</td>
+      <td>Fragilaria undata Wm. Sm.</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>26</td>
+      <td>Fragilaria undata Wm. Sm., var.?</td>
+      <td class="ar"><a href="#page44">44</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>30</td>
+      <td>Fragilaria construens (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>31</td>
+      <td>Fragilaria harrisonii (Wm. Sm.) Grun.</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>34</td>
+      <td>Fragilaria capucina var. mesolepta Rab.</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>35</td>
+      <td>Fragilaria parasitica (Wm. Sm.)</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>36</td>
+      <td>Fragilaria sp. ?</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>37</td>
+      <td>Fragilaria linearis Cstr.</td>
+      <td class="ar"><a href="#page45">45</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">RHAPHONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>38</td>
+      <td>Rhaphoneis amphiceros Ehr.</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>39-40</td>
+      <td>Rhaphoneis amphiceros var. rhombica Grun.</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>41</td>
+      <td>Rhaphoneis belgica var. intermedia Grun.</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">SYNEDRA</td>
+    </tr>
+    <tr class="pb05">
+      <td>32-33</td>
+      <td>Synedra radians Kuetz.</td>
+      <td class="ar"><a href="#page49">49</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate10.jpg"><img
+      style="width:100%" src="images/plate10.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate11"></div>
+
+  <h2>PLATE 11</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 11" summary="Plate 11">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">SYNEDRA&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-5-6</td>
+            <td>Synedra ulna (Nitzsch) Ehr. Sporangial</td>
+            <td class="ar"><a href="#page47">47</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Synedra danica Kuetz.</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Synedra biceps (Kuetz.) A. S.</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4-7-11</td>
+            <td>Synedra ulna (Nitzsch) Ehr.</td>
+            <td class="ar"><a href="#page47">47</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Synedra capitata Ehr.</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9-18</td>
+            <td>Synedra acus Kuetz.</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Synedra fulgens (Grev.) Wm. Sm.</td>
+            <td class="ar"><a href="#page50">50</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12-13</td>
+            <td>Synedra goulardi Bréb.</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14-15-16</td>
+            <td>Synedra pulchella (Ralfs) Kuetz.</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Synedra pulchella var. abnormis Macchiati?</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate11.jpg"><img
+      style="width:100%" src="images/plate11.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 11" summary="Plate 11">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">SYNEDRA&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-5-6</td>
+      <td>Synedra ulna (Nitzsch) Ehr. Sporangial</td>
+      <td class="ar"><a href="#page47">47</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Synedra danica Kuetz.</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Synedra biceps (Kuetz.) A. S.</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4-7-11</td>
+      <td>Synedra ulna (Nitzsch) Ehr.</td>
+      <td class="ar"><a href="#page47">47</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Synedra capitata Ehr.</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9-18</td>
+      <td>Synedra acus Kuetz.</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Synedra fulgens (Grev.) Wm. Sm.</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12-13</td>
+      <td>Synedra goulardi Bréb.</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14-15-16</td>
+      <td>Synedra pulchella (Ralfs) Kuetz.</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Synedra pulchella var. abnormis Macchiati?</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate11.jpg"><img
+      style="width:100%" src="images/plate11.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate12"></div>
+
+  <h2>PLATE 12</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 12" summary="Plate 12">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">SYNEDRA&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Synedra oxyrhynchus var. undulata Grun.</td>
+            <td class="ar"><a href="#page48">48</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Synedra pulchella var. flexella n. var.</td>
+            <td class="ar"><a href="#page49">49</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Synedra affinis Kuetz.</td>
+            <td class="ar"><a href="#page50">50</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Synedra affinis var. tabulata (Ag.) V. H.</td>
+            <td class="ar"><a href="#page50">50</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5-6</td>
+            <td>Synedra vaucheriæ var. parvula (Kuetz.) Rab.</td>
+            <td class="ar"><a href="#page49">49</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Synedra affinis var. parva (Kuetz.) V. H.</td>
+            <td class="ar"><a href="#page50">50</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Synedra radians (Kuetz.) H. L. S.</td>
+            <td class="ar"><a href="#page49">49</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">DIMEROGRAMMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>9-10</td>
+            <td>Dimerogramma marinum (Greg.)</td>
+            <td class="ar"><a href="#page46">46</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Dimerogramma surirella (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page46">46</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12-13-14</td>
+            <td>Dimerogramma minus (Greg.) Ralfs.</td>
+            <td class="ar"><a href="#page47">47</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">TRACHYSPHENIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Trachysphenia australis Petit.</td>
+            <td class="ar"><a href="#page47">47</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">ACTINELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>16-17-18</td>
+            <td>Actinella punctata Lewis.</td>
+            <td class="ar"><a href="#page54">54</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">ASTERIONELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>19-20-21</td>
+            <td>Asterionella formosa Hass.</td>
+            <td class="ar"><a href="#page50">50</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Asterionella inflata Heib.</td>
+            <td class="ar"><a href="#page50">50</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">EUNOTIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Eunotia hemicyclus (Ehr.) Ralfs</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24-25</td>
+            <td>Eunotia lunaris (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate12.jpg"><img
+      style="width:100%" src="images/plate12.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 12" summary="Plate 12">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">SYNEDRA&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Synedra oxyrhynchus var. undulata Grun.</td>
+      <td class="ar"><a href="#page48">48</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Synedra pulchella var. flexella n. var.</td>
+      <td class="ar"><a href="#page49">49</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Synedra affinis Kuetz.</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Synedra affinis var. tabulata (Ag.) V. H.</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5-6</td>
+      <td>Synedra vaucheriæ var. parvula (Kuetz.) Rab.</td>
+      <td class="ar"><a href="#page49">49</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Synedra affinis var. parva (Kuetz.) V. H.</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Synedra radians (Kuetz.) H. L. S.</td>
+      <td class="ar"><a href="#page49">49</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">DIMEROGRAMMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>9-10</td>
+      <td>Dimerogramma marinum (Greg.)</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Dimerogramma surirella (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page46">46</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12-13-14</td>
+      <td>Dimerogramma minus (Greg.) Ralfs.</td>
+      <td class="ar"><a href="#page47">47</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">TRACHYSPHENIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Trachysphenia australis Petit.</td>
+      <td class="ar"><a href="#page47">47</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">ACTINELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>16-17-18</td>
+      <td>Actinella punctata Lewis.</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">ASTERIONELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>19-20-21</td>
+      <td>Asterionella formosa Hass.</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Asterionella inflata Heib.</td>
+      <td class="ar"><a href="#page50">50</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">EUNOTIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Eunotia hemicyclus (Ehr.) Ralfs</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24-25</td>
+      <td>Eunotia lunaris (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate12.jpg"><img
+      style="width:100%" src="images/plate12.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate13"></div>
+
+  <h2>PLATE 13</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 13" summary="Plate 13">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">EUNOTIA&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2</td>
+            <td>Eunotia major (Wm. Sm.) Rab.</td>
+            <td class="ar"><a href="#page51">51</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Eunotia gracilis (Ehr.) Rab.</td>
+            <td class="ar"><a href="#page51">51</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Eunotia major (Wm. Sm.) Rab. (intermediate form)</td>
+            <td class="ar"><a href="#page51">51</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Eunotia prærupta Ehr.</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6-7</td>
+            <td>Eunotia pectinalis (Kuetz.)</td>
+            <td class="ar"><a href="#page52">52</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8-10</td>
+            <td>Eunotia pectinalis var. undulata Ralfs</td>
+            <td class="ar"><a href="#page52">52</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Eunotia pectinalis var. solierolii (Kuetz.)</td>
+            <td class="ar"><a href="#page52">52</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Eunotia luna Ehr. var.?</td>
+            <td class="ar"><a href="#page52">52</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Eunotia pectinalis var. ventricosa Grun.</td>
+            <td class="ar"><a href="#page52">52</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Eunotia robusta Ralfs (E. scalaris Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Eunotia robusta Ralfs (E. prioritis Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Eunotia robusta Ralfs (E. decadon Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Eunotia robusta Ralfs (E. octodon Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17-22</td>
+            <td>Eunotia robusta Ralfs (E. heptodon Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Eunotia bactriana Ehr.</td>
+            <td class="ar"><a href="#page54">54</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19</td>
+            <td>Eunotia prærupta var. bidens Grun.</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Eunotia bidentula Wm. Sm.</td>
+            <td class="ar"><a href="#page54">54</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Eunotia robusta Ralfs (E. diadema Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Eunotia prærupta Ehr. var.?</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Eunotia robusta Ralfs (E. triodon Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>25</td>
+            <td>Eunotia robusta Ralfs (E. tetraodon Ehr.)</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>26</td>
+            <td>Eunotia formica Ehr. var.?</td>
+            <td class="ar"><a href="#page54">54</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>27</td>
+            <td>Eunotia biceps Ehr.</td>
+            <td class="ar"><a href="#page53">53</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>28-29</td>
+            <td>Eunotia sp.?</td>
+            <td class="ar"><a href="#page54">54</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>30-31</td>
+            <td>Eunotia veneris Kuetz.</td>
+            <td class="ar"><a href="#page52">52</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>32</td>
+            <td>Eunotia nymanniana Grun.</td>
+            <td class="ar"><a href="#page51">51</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate13.jpg"><img
+      style="width:100%" src="images/plate13.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 13" summary="Plate 13">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">EUNOTIA&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2</td>
+      <td>Eunotia major (Wm. Sm.) Rab.</td>
+      <td class="ar"><a href="#page51">51</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Eunotia gracilis (Ehr.) Rab.</td>
+      <td class="ar"><a href="#page51">51</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Eunotia major (Wm. Sm.) Rab. (intermediate form)</td>
+      <td class="ar"><a href="#page51">51</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Eunotia prærupta Ehr.</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6-7</td>
+      <td>Eunotia pectinalis (Kuetz.)</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8-10</td>
+      <td>Eunotia pectinalis var. undulata Ralfs</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Eunotia pectinalis var. solierolii (Kuetz.)</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Eunotia luna Ehr. var.?</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Eunotia pectinalis var. ventricosa Grun.</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Eunotia robusta Ralfs (E. scalaris Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Eunotia robusta Ralfs (E. prioritis Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Eunotia robusta Ralfs (E. decadon Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Eunotia robusta Ralfs (E. octodon Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17-22</td>
+      <td>Eunotia robusta Ralfs (E. heptodon Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Eunotia bactriana Ehr.</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19</td>
+      <td>Eunotia prærupta var. bidens Grun.</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Eunotia bidentula Wm. Sm.</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Eunotia robusta Ralfs (E. diadema Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Eunotia prærupta Ehr. var.?</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Eunotia robusta Ralfs (E. triodon Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>25</td>
+      <td>Eunotia robusta Ralfs (E. tetraodon Ehr.)</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>26</td>
+      <td>Eunotia formica Ehr. var.?</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>27</td>
+      <td>Eunotia biceps Ehr.</td>
+      <td class="ar"><a href="#page53">53</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>28-29</td>
+      <td>Eunotia sp.?</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>30-31</td>
+      <td>Eunotia veneris Kuetz.</td>
+      <td class="ar"><a href="#page52">52</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>32</td>
+      <td>Eunotia nymanniana Grun.</td>
+      <td class="ar"><a href="#page51">51</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate13.jpg"><img
+      style="width:100%" src="images/plate13.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate14"></div>
+
+  <h2>PLATE 14</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 14" summary="Plate 14">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">AMPHIPRORA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2</td>
+            <td>Amphiprora pulchra Bail.</td>
+            <td class="ar"><a href="#page68">68</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Amphiprora alata Kuetz.</td>
+            <td class="ar"><a href="#page68">68</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Amphiprora conspicua Grev.</td>
+            <td class="ar"><a href="#page68">68</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Amphiprora paludosa Wm. Sm.</td>
+            <td class="ar"><a href="#page68">68</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6-7</td>
+            <td>Amphiprora ornata Bail.</td>
+            <td class="ar"><a href="#page68">68</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">TROPIDONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>8-9</td>
+            <td>Tropidoneis lepidoptera (Greg.) Cleve.</td>
+            <td class="ar"><a href="#page69">69</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">SCOLIOTROPIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>10-11</td>
+            <td>Scoliotropis latestriata var. amphora Cleve.</td>
+            <td class="ar"><a href="#page69">69</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate14.jpg"><img
+      style="width:100%" src="images/plate14.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 14" summary="Plate 14">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">AMPHIPRORA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2</td>
+      <td>Amphiprora pulchra Bail.</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Amphiprora alata Kuetz.</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Amphiprora conspicua Grev.</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Amphiprora paludosa Wm. Sm.</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6-7</td>
+      <td>Amphiprora ornata Bail.</td>
+      <td class="ar"><a href="#page68">68</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">TROPIDONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>8-9</td>
+      <td>Tropidoneis lepidoptera (Greg.) Cleve.</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">SCOLIOTROPIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>10-11</td>
+      <td>Scoliotropis latestriata var. amphora Cleve.</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate14.jpg"><img
+      style="width:100%" src="images/plate14.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate15"></div>
+
+  <h2>PLATE 15</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 15" summary="Plate 15">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">AMPHORA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Amphora robusta Greg.</td>
+            <td class="ar"><a href="#page65">65</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Amphora crassa Greg.</td>
+            <td class="ar"><a href="#page65">65</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Amphora obtusa Greg.</td>
+            <td class="ar"><a href="#page67">67</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5-6-19</td>
+            <td>Amphora proteus Greg.</td>
+            <td class="ar"><a href="#page65">65</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Amphora ovalis (Bréb.) Kuetz.</td>
+            <td class="ar"><a href="#page65">65</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8-18</td>
+            <td>Amphora coffæiformis (Ag.) Kuetz.</td>
+            <td class="ar"><a href="#page66">66</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9-10</td>
+            <td>Amphora lineolata Ehr.</td>
+            <td class="ar"><a href="#page66">66</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Amphora areolata Grun.</td>
+            <td class="ar"><a href="#page66">66</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12-21</td>
+            <td>Amphora ostrearia Bréb.</td>
+            <td class="ar"><a href="#page66">66</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Amphora lævis Greg.</td>
+            <td class="ar"><a href="#page66">66</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14-15</td>
+            <td>Amphora ocellata var. cingulata Cleve.</td>
+            <td class="ar"><a href="#page67">67</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Amphora angusta var. culensteinii Grun.</td>
+            <td class="ar"><a href="#page67">67</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Amphora arenaria Donk.</td>
+            <td class="ar"><a href="#page67">67</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Amphora acuta Greg.</td>
+            <td class="ar"><a href="#page66">66</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">AURICULA</td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Auricula mucronata (H. L. Smith) Peragallo</td>
+            <td class="ar"><a href="#page69">69</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate15.jpg"><img
+      style="width:100%" src="images/plate15.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 15" summary="Plate 15">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">AMPHORA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Amphora robusta Greg.</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Amphora crassa Greg.</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Amphora obtusa Greg.</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5-6-19</td>
+      <td>Amphora proteus Greg.</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Amphora ovalis (Bréb.) Kuetz.</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8-18</td>
+      <td>Amphora coffæiformis (Ag.) Kuetz.</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9-10</td>
+      <td>Amphora lineolata Ehr.</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Amphora areolata Grun.</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12-21</td>
+      <td>Amphora ostrearia Bréb.</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Amphora lævis Greg.</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14-15</td>
+      <td>Amphora ocellata var. cingulata Cleve.</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Amphora angusta var. culensteinii Grun.</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Amphora arenaria Donk.</td>
+      <td class="ar"><a href="#page67">67</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Amphora acuta Greg.</td>
+      <td class="ar"><a href="#page66">66</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">AURICULA</td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Auricula mucronata (H. L. Smith) Peragallo</td>
+      <td class="ar"><a href="#page69">69</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate15.jpg"><img
+      style="width:100%" src="images/plate15.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate16"></div>
+
+  <h2>PLATE 16</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 16" summary="Plate 16">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">ACHNANTHES</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2</td>
+            <td>Achnanthes longipes Ag.</td>
+            <td class="ar"><a href="#page58">58</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Achnanthes brevipes Ag.</td>
+            <td class="ar"><a href="#page59">59</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4-5-6</td>
+            <td>Achnanthes subsessilis Kuetz.</td>
+            <td class="ar"><a href="#page59">59</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7-8</td>
+            <td>Achnanthes inflata (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page59">59</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Achnanthes coarctata (Bréb.) Grun.</td>
+            <td class="ar"><a href="#page59">59</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10-11-12</td>
+            <td>Achnanthes lanceolata (Bréb.) Grun.</td>
+            <td class="ar"><a href="#page59">59</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Achnanthes danica (Floegel) Grun. (lower valve)</td>
+            <td class="ar"><a href="#page60">60</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14-15</td>
+            <td>Achnanthes exigua Grun.</td>
+            <td class="ar"><a href="#page59">59</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16-17</td>
+            <td>Achnanthes linearis forma curta H. L. Smith</td>
+            <td class="ar"><a href="#page59">59</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">COCCONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Cocconeis scutellum var.?</td>
+            <td class="ar"><a href="#page57">57</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19-20</td>
+            <td>Cocconeis placentula Ehr.</td>
+            <td class="ar"><a href="#page57">57</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Cocconeis scutellum Ehr. (upper valve)</td>
+            <td class="ar"><a href="#page57">57</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Cocconeis dirupta Greg. (lower valve)</td>
+            <td class="ar"><a href="#page58">58</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23-24</td>
+            <td>Cocconeis pediculus Ehr.</td>
+            <td class="ar"><a href="#page57">57</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>25-26</td>
+            <td>Cocconeis pellucida Grun.</td>
+            <td class="ar"><a href="#page58">58</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>27-28</td>
+            <td>Cocconeis scutellum var. ornata Grun.</td>
+            <td class="ar"><a href="#page57">57</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>29</td>
+            <td>Cocconeis placentula var. lineata (Ehr.) V. H.</td>
+            <td class="ar"><a href="#page58">58</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">ANORTHONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>30-31</td>
+            <td>Anorthoneis excentrica (Donk.) Grun.</td>
+            <td class="ar"><a href="#page56">56</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate16.jpg"><img
+      style="width:100%" src="images/plate16.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 16" summary="Plate 16">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">ACHNANTHES</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2</td>
+      <td>Achnanthes longipes Ag.</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Achnanthes brevipes Ag.</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4-5-6</td>
+      <td>Achnanthes subsessilis Kuetz.</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7-8</td>
+      <td>Achnanthes inflata (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Achnanthes coarctata (Bréb.) Grun.</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10-11-12</td>
+      <td>Achnanthes lanceolata (Bréb.) Grun.</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Achnanthes danica (Floegel) Grun. (lower valve)</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14-15</td>
+      <td>Achnanthes exigua Grun.</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16-17</td>
+      <td>Achnanthes linearis forma curta H. L. Smith</td>
+      <td class="ar"><a href="#page59">59</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">COCCONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Cocconeis scutellum var.?</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19-20</td>
+      <td>Cocconeis placentula Ehr.</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Cocconeis scutellum Ehr. (upper valve)</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Cocconeis dirupta Greg. (lower valve)</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23-24</td>
+      <td>Cocconeis pediculus Ehr.</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>25-26</td>
+      <td>Cocconeis pellucida Grun.</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>27-28</td>
+      <td>Cocconeis scutellum var. ornata Grun.</td>
+      <td class="ar"><a href="#page57">57</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>29</td>
+      <td>Cocconeis placentula var. lineata (Ehr.) V. H.</td>
+      <td class="ar"><a href="#page58">58</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">ANORTHONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>30-31</td>
+      <td>Anorthoneis excentrica (Donk.) Grun.</td>
+      <td class="ar"><a href="#page56">56</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate16.jpg"><img
+      style="width:100%" src="images/plate16.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate17"></div>
+
+  <h2>PLATE 17</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 17" summary="Plate 17">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">FRUSTULIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Frustulia lewisiana (Grev.) De Toni</td>
+            <td class="ar"><a href="#page77">77</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Frustulia rhomboides (Ehr.) De Toni</td>
+            <td class="ar"><a href="#page77">77</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Frustulia rhomboides var. amphipleuroides Grun.</td>
+            <td class="ar"><a href="#page77">77</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Frustulia vulgaris (Thwaites) De Toni</td>
+            <td class="ar"><a href="#page77">77</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Frustulia interposita (Lewis) De Toni</td>
+            <td class="ar"><a href="#page78">78</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Frustulia rhomboides var. saxonica (Rab.) De Toni</td>
+            <td class="ar"><a href="#page77">77</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">BREBISSONIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Brébissonia b&#x0153;ckii (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page79">79</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Brébissonia palmerii n. sp.</td>
+            <td class="ar"><a href="#page80">80</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">AMPHIPLEURA</td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Amphipleura pellucida Kuetz.</td>
+            <td class="ar"><a href="#page78">78</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10-11</td>
+            <td>Amphipleura rutilans (Trentepohl) Cl.</td>
+            <td class="ar"><a href="#page78">78</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">ANOM&#x0152;ONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Anom&#x0153;oneis serians (Bréb.) Cl.</td>
+            <td class="ar"><a href="#page80">80</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Anom&#x0153;oneis serians forma minor</td>
+            <td class="ar"><a href="#page80">80</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Anom&#x0153;oneis follis (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page80">80</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">TRACHYNEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Trachyneis aspera var. intermedia Grun.</td>
+            <td class="ar"><a href="#page70">70</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">MASTOGLOIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Mastogloia kinsmanii Lewis</td>
+            <td class="ar"><a href="#page87">87</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Mastogloia angulata Lewis</td>
+            <td class="ar"><a href="#page87">87</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Mastogloia lanceolata Thwaites</td>
+            <td class="ar"><a href="#page87">87</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19</td>
+            <td>Mastogloia smithii Thwaites</td>
+            <td class="ar"><a href="#page87">87</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Mastogloia elegans Lewis</td>
+            <td class="ar"><a href="#page87">87</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21-22-23</td>
+            <td>Mastogloia apiculata Wm. Sm.</td>
+            <td class="ar"><a href="#page87">87</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Mastogloia exigua Lewis</td>
+            <td class="ar"><a href="#page87">87</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate17.jpg"><img
+      style="width:100%" src="images/plate17.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 17" summary="Plate 17">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">FRUSTULIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Frustulia lewisiana (Grev.) De Toni</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Frustulia rhomboides (Ehr.) De Toni</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Frustulia rhomboides var. amphipleuroides Grun.</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Frustulia vulgaris (Thwaites) De Toni</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Frustulia interposita (Lewis) De Toni</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Frustulia rhomboides var. saxonica (Rab.) De Toni</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">BREBISSONIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Brébissonia b&#x0153;ckii (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page79">79</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Brébissonia palmerii n. sp.</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">AMPHIPLEURA</td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Amphipleura pellucida Kuetz.</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10-11</td>
+      <td>Amphipleura rutilans (Trentepohl) Cl.</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">ANOM&#x0152;ONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Anom&#x0153;oneis serians (Bréb.) Cl.</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Anom&#x0153;oneis serians forma minor</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Anom&#x0153;oneis follis (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">TRACHYNEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Trachyneis aspera var. intermedia Grun.</td>
+      <td class="ar"><a href="#page70">70</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">MASTOGLOIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Mastogloia kinsmanii Lewis</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Mastogloia angulata Lewis</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Mastogloia lanceolata Thwaites</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19</td>
+      <td>Mastogloia smithii Thwaites</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Mastogloia elegans Lewis</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21-22-23</td>
+      <td>Mastogloia apiculata Wm. Sm.</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Mastogloia exigua Lewis</td>
+      <td class="ar"><a href="#page87">87</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate17.jpg"><img
+      style="width:100%" src="images/plate17.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate18"></div>
+
+  <h2>PLATE 18</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 18" summary="Plate 18">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">CYMBELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Cymbella aspera (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page61">61</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Cymbella cymbiformis (Kuetz.) Bréb.</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Cymbella cistula (Hempr.) Kirchn.</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Cymbella lanceolata (Ehr.) Kirchn.</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Cymbella mexicana (Ehr.) A. S.</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Cymbella naviculiformis Auerswald.</td>
+            <td class="ar"><a href="#page60">60</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Cymbella tumida (Bréb.) V. H.</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Cymbella philadelphica n. sp.</td>
+            <td class="ar"><a href="#page63">63</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Cymbella ehrenbergii Kuetz.</td>
+            <td class="ar"><a href="#page60">60</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Cymbella heteropleura (Ehr.) Kuetz.</td>
+            <td class="ar"><a href="#page60">60</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Cymbella rhomboidea n. sp.</td>
+            <td class="ar"><a href="#page63">63</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Cymbella turgida (Greg.) Cl. var.?</td>
+            <td class="ar"><a href="#page63">63</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Cymbella sinuata Greg.</td>
+            <td class="ar"><a href="#page61">61</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Cymbella ventricosa Kuetz.</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15-19</td>
+            <td>Cymbella excisa (Kuetz.) De Toni.</td>
+            <td class="ar"><a href="#page61">61</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Cymbella amphicephala Nægeli.</td>
+            <td class="ar"><a href="#page61">61</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Cymbella cuspidata Kuetz.</td>
+            <td class="ar"><a href="#page60">60</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Cymbella affinis Kuetz.</td>
+            <td class="ar"><a href="#page61">61</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Cymbella gracilis (Rab.) Cl.</td>
+            <td class="ar"><a href="#page64">64</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Cymbella prostrata (Berk.) Cl.</td>
+            <td class="ar"><a href="#page63">63</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Cymbella ventricosa Kuetz.?</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Cymbella turgida (Greg.) Cl.</td>
+            <td class="ar"><a href="#page63">63</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Cymbella triangulum (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page63">63</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>25</td>
+            <td>Cymbella lacustris (Ag.) Cl.</td>
+            <td class="ar"><a href="#page64">64</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate18.jpg"><img
+      style="width:100%" src="images/plate18.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 18" summary="Plate 18">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">CYMBELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Cymbella aspera (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Cymbella cymbiformis (Kuetz.) Bréb.</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Cymbella cistula (Hempr.) Kirchn.</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Cymbella lanceolata (Ehr.) Kirchn.</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Cymbella mexicana (Ehr.) A. S.</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Cymbella naviculiformis Auerswald.</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Cymbella tumida (Bréb.) V. H.</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Cymbella philadelphica n. sp.</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Cymbella ehrenbergii Kuetz.</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Cymbella heteropleura (Ehr.) Kuetz.</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Cymbella rhomboidea n. sp.</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Cymbella turgida (Greg.) Cl. var.?</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Cymbella sinuata Greg.</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Cymbella ventricosa Kuetz.</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15-19</td>
+      <td>Cymbella excisa (Kuetz.) De Toni.</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Cymbella amphicephala Nægeli.</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Cymbella cuspidata Kuetz.</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Cymbella affinis Kuetz.</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Cymbella gracilis (Rab.) Cl.</td>
+      <td class="ar"><a href="#page64">64</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Cymbella prostrata (Berk.) Cl.</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Cymbella ventricosa Kuetz.?</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Cymbella turgida (Greg.) Cl.</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Cymbella triangulum (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page63">63</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>25</td>
+      <td>Cymbella lacustris (Ag.) Cl.</td>
+      <td class="ar"><a href="#page64">64</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate18.jpg"><img
+      style="width:100%" src="images/plate18.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate19"></div>
+
+  <h2>PLATE 19</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 19" summary="Plate 19">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">GOMPHONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Gomphoneis mamilla (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page70">70</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Gomphoneis herculaneum (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page70">70</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">GOMPHONEMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Gomphonema montanum Schum.</td>
+            <td class="ar"><a href="#page71">71</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Gomphonema geminatum Lyng.</td>
+            <td class="ar"><a href="#page71">71</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Gomphonema acuminatum var. turris (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page71">71</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6-12</td>
+            <td>Gomphonema lanceolatum var. insignis (Greg.) Cl.</td>
+            <td class="ar"><a href="#page71">71</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Gomphonema acuminatum var. coronata (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page71">71</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Gomphonema constrictum Ehr.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9-10</td>
+            <td>Gomphonema sphærophorum Ehr.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Gomphonema acuminatum var. turris (Ehr.) Cl.?</td>
+            <td class="ar"><a href="#page71">71</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Gomphonema ventricosum Greg.</td>
+            <td class="ar"><a href="#page73">73</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Gomphonema intricatum Kuetz.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Gomphonema æquale Greg.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Gomphonema sarcophagus Greg.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Gomphonema parvulum var. micropus (Kuetz.) Cl.</td>
+            <td class="ar"><a href="#page73">73</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18-19</td>
+            <td>Gomphonema angustatum Kuetz.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Gomphonema acuminatum var. trigonocephala (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page71">71</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Gomphonema augur Ehr.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Gomphonema capitatum Ehr.</td>
+            <td class="ar"><a href="#page72">72</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Gomphonema olivaceum Lyng.</td>
+            <td class="ar"><a href="#page73">73</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Gomphonema brasiliense var. demeraræ Grun.?</td>
+            <td class="ar"><a href="#page73">73</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">RHOICOSPHENIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>25-26-27</td>
+            <td>Rhoicosphenia curvata (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page56">56</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate19.jpg"><img
+      style="width:100%" src="images/plate19.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 19" summary="Plate 19">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">GOMPHONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Gomphoneis mamilla (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page70">70</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Gomphoneis herculaneum (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page70">70</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">GOMPHONEMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Gomphonema montanum Schum.</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Gomphonema geminatum Lyng.</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Gomphonema acuminatum var. turris (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6-12</td>
+      <td>Gomphonema lanceolatum var. insignis (Greg.) Cl.</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Gomphonema acuminatum var. coronata (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Gomphonema constrictum Ehr.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9-10</td>
+      <td>Gomphonema sphærophorum Ehr.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Gomphonema acuminatum var. turris (Ehr.) Cl.?</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Gomphonema ventricosum Greg.</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Gomphonema intricatum Kuetz.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Gomphonema æquale Greg.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Gomphonema sarcophagus Greg.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Gomphonema parvulum var. micropus (Kuetz.) Cl.</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18-19</td>
+      <td>Gomphonema angustatum Kuetz.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Gomphonema acuminatum var. trigonocephala (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page71">71</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Gomphonema augur Ehr.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Gomphonema capitatum Ehr.</td>
+      <td class="ar"><a href="#page72">72</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Gomphonema olivaceum Lyng.</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Gomphonema brasiliense var. demeraræ Grun.?</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">RHOICOSPHENIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>25-26-27</td>
+      <td>Rhoicosphenia curvata (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page56">56</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate19.jpg"><img
+      style="width:100%" src="images/plate19.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate20"></div>
+
+  <h2>PLATE 20</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 20" summary="Plate 20">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">DICTYONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Dictyoneis marginata var. maxima n. var.</td>
+            <td class="ar"><a href="#page79">79</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Dictyoneis marginata var. commutata Cleve.</td>
+            <td class="ar"><a href="#page79">79</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Dictyoneis marginata var. typica Cleve.</td>
+            <td class="ar"><a href="#page78">78</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">DIPLONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Diploneis crabro var. pandura (Bréb.) Cl.</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Diploneis campylodiscus (Grun.) Cl.</td>
+            <td class="ar"><a href="#page86">86</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7-8</td>
+            <td>Diploneis gruendleri (A. S.) Cl.</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Diploneis crabro Ehr. var.?</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Diploneis excentrica n. sp.</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Diploneis fusca var. delicata (A. S.) Cl.</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Diploneis puella (Schum.) Cl.</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Diploneis crabro var. pandurella Cl.?</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Diploneis elliptica (Kuetz.) Cl.</td>
+            <td class="ar"><a href="#page84">84</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Diploneis crabro var. expleta (A. S.) Cl.</td>
+            <td class="ar"><a href="#page85">85</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Diploneis geminata (Grev.) Cl.</td>
+            <td class="ar"><a href="#page86">86</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Diploneis smithii (Bréb.) Cl.</td>
+            <td class="ar"><a href="#page84">84</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">NAVICULA</td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Navicula lyra Ehr. var.?</td>
+            <td class="ar"><a href="#page93">93</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate20.jpg"><img
+      style="width:100%" src="images/plate20.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 20" summary="Plate 20">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">DICTYONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Dictyoneis marginata var. maxima n. var.</td>
+      <td class="ar"><a href="#page79">79</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Dictyoneis marginata var. commutata Cleve.</td>
+      <td class="ar"><a href="#page79">79</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Dictyoneis marginata var. typica Cleve.</td>
+      <td class="ar"><a href="#page78">78</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">DIPLONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Diploneis crabro var. pandura (Bréb.) Cl.</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Diploneis campylodiscus (Grun.) Cl.</td>
+      <td class="ar"><a href="#page86">86</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7-8</td>
+      <td>Diploneis gruendleri (A. S.) Cl.</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Diploneis crabro Ehr. var.?</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Diploneis excentrica n. sp.</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Diploneis fusca var. delicata (A. S.) Cl.</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Diploneis puella (Schum.) Cl.</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Diploneis crabro var. pandurella Cl.?</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Diploneis elliptica (Kuetz.) Cl.</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Diploneis crabro var. expleta (A. S.) Cl.</td>
+      <td class="ar"><a href="#page85">85</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Diploneis geminata (Grev.) Cl.</td>
+      <td class="ar"><a href="#page86">86</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Diploneis smithii (Bréb.) Cl.</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">NAVICULA</td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Navicula lyra Ehr. var.?</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate20.jpg"><img
+      style="width:100%" src="images/plate20.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate21"></div>
+
+  <h2>PLATE 21</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 21" summary="Plate 21">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">CALONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Caloneis permagna (Bail.) Cl.</td>
+            <td class="ar"><a href="#page82">82</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Caloneis permagna var. lewisiana n. var.</td>
+            <td class="ar"><a href="#page82">82</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Caloneis silicula (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page81">81</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Caloneis silicula var. inflata (Grun.) Cl.</td>
+            <td class="ar"><a href="#page81">81</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Caloneis brevis var. vexans (Grun.) Cl.</td>
+            <td class="ar"><a href="#page82">82</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6-7</td>
+            <td>Caloneis wardii Cl.</td>
+            <td class="ar"><a href="#page82">82</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Caloneis trinodis (Lewis)</td>
+            <td class="ar"><a href="#page81">81</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Caloneis trinodis (Lewis) var.?</td>
+            <td class="ar"><a href="#page81">81</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Caloneis powellii (Lewis) Cl.</td>
+            <td class="ar"><a href="#page83">83</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Caloneis formosa (Greg.) Cl.</td>
+            <td class="ar"><a href="#page82">82</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">NEIDIUM</td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Neidium affine (Ehr.) Pfitzer</td>
+            <td class="ar"><a href="#page83">83</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Neidium affine var. genuina forma minor Cl.</td>
+            <td class="ar"><a href="#page83">83</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Neidium affine var. amphirhyncus (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page83">83</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Neidium amphigomphus (Ehr.) Pfitzer.</td>
+            <td class="ar"><a href="#page83">83</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Neidium hitchcockii (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page84">84</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Neidium productum (Wm. Sm.) Cl.</td>
+            <td class="ar"><a href="#page83">83</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Neidium iridus (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page84">84</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate21.jpg"><img
+      style="width:100%" src="images/plate21.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 21" summary="Plate 21">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">CALONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Caloneis permagna (Bail.) Cl.</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Caloneis permagna var. lewisiana n. var.</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Caloneis silicula (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Caloneis silicula var. inflata (Grun.) Cl.</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Caloneis brevis var. vexans (Grun.) Cl.</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6-7</td>
+      <td>Caloneis wardii Cl.</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Caloneis trinodis (Lewis)</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Caloneis trinodis (Lewis) var.?</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Caloneis powellii (Lewis) Cl.</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Caloneis formosa (Greg.) Cl.</td>
+      <td class="ar"><a href="#page82">82</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">NEIDIUM</td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Neidium affine (Ehr.) Pfitzer</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Neidium affine var. genuina forma minor Cl.</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Neidium affine var. amphirhyncus (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Neidium amphigomphus (Ehr.) Pfitzer.</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Neidium hitchcockii (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Neidium productum (Wm. Sm.) Cl.</td>
+      <td class="ar"><a href="#page83">83</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Neidium iridus (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page84">84</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate21.jpg"><img
+      style="width:100%" src="images/plate21.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate22"></div>
+
+  <h2>PLATE 22</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 22" summary="Plate 22">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">PLEUROSIGMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Pleurosigma strigosum Wm. Sm.</td>
+            <td class="ar"><a href="#page74">74</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Pleurosigma rigidum Wm. Sm.</td>
+            <td class="ar"><a href="#page75">75</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Pleurosigma angulatum (Quekett) Cl.</td>
+            <td class="ar"><a href="#page74">74</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Pleurosigma obscurum Wm. Sm.</td>
+            <td class="ar"><a href="#page74">74</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Pleurosigma formosum Wm. Sm.</td>
+            <td class="ar"><a href="#page73">73</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Pleurosigma naviculaceum Bréb.</td>
+            <td class="ar"><a href="#page74">74</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Pleurosigma æstuarii Bréb.</td>
+            <td class="ar"><a href="#page74">74</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Pleurosigma virginiacum H. L. Smith</td>
+            <td class="ar"><a href="#page74">74</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate22.jpg"><img
+      style="width:100%" src="images/plate22.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 22" summary="Plate 22">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">PLEUROSIGMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Pleurosigma strigosum Wm. Sm.</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Pleurosigma rigidum Wm. Sm.</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Pleurosigma angulatum (Quekett) Cl.</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Pleurosigma obscurum Wm. Sm.</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Pleurosigma formosum Wm. Sm.</td>
+      <td class="ar"><a href="#page73">73</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Pleurosigma naviculaceum Bréb.</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Pleurosigma æstuarii Bréb.</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Pleurosigma virginiacum H. L. Smith</td>
+      <td class="ar"><a href="#page74">74</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate22.jpg"><img
+      style="width:100%" src="images/plate22.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate23"></div>
+
+  <h2>PLATE 23</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 23" summary="Plate 23">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">GYROSIGMA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Gyrosigma strigilis (Wm. Sm.) Cl.</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Gyrosigma balticum (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page75">75</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Gyrosigma hippocampus (Ehr.)</td>
+            <td class="ar"><a href="#page75">75</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Gyrosigma simile (Grun.)</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Gyrosigma acuminatum (Kuetz.) Cl.</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Gyrosigma scalproides (Rab.) Cl.</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Gyrosigma parkeri var. stauroneioides Grun.</td>
+            <td class="ar"><a href="#page75">75</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Gyrosigma spencerii var. nodifera Grun.</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Gyrosigma fasciola (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page77">77</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate23.jpg"><img
+      style="width:100%" src="images/plate23.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 23" summary="Plate 23">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">GYROSIGMA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Gyrosigma strigilis (Wm. Sm.) Cl.</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Gyrosigma balticum (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Gyrosigma hippocampus (Ehr.)</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Gyrosigma simile (Grun.)</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Gyrosigma acuminatum (Kuetz.) Cl.</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Gyrosigma scalproides (Rab.) Cl.</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Gyrosigma parkeri var. stauroneioides Grun.</td>
+      <td class="ar"><a href="#page75">75</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Gyrosigma spencerii var. nodifera Grun.</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Gyrosigma fasciola (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page77">77</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate23.jpg"><img
+      style="width:100%" src="images/plate23.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate24"></div>
+
+  <h2>PLATE 24</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 24" summary="Plate 24">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">NAVICULA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Navicula maculata (Bail.) Cl.</td>
+            <td class="ar"><a href="#page90">90</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Navicula prætexta Ehr.</td>
+            <td class="ar"><a href="#page92">92</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Navicula latissima Greg.</td>
+            <td class="ar"><a href="#page90">90</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Navicula irrorata Grev.</td>
+            <td class="ar"><a href="#page93">93</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Navicula latissima var. elongata (Pant.) Cl.</td>
+            <td class="ar"><a href="#page91">91</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Navicula fuchsii Pant.</td>
+            <td class="ar"><a href="#page91">91</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate24.jpg"><img
+      style="width:100%" src="images/plate24.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 24" summary="Plate 24">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">NAVICULA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Navicula maculata (Bail.) Cl.</td>
+      <td class="ar"><a href="#page90">90</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Navicula prætexta Ehr.</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Navicula latissima Greg.</td>
+      <td class="ar"><a href="#page90">90</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Navicula irrorata Grev.</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Navicula latissima var. elongata (Pant.) Cl.</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Navicula fuchsii Pant.</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate24.jpg"><img
+      style="width:100%" src="images/plate24.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate25"></div>
+
+  <h2>PLATE 25</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 25" summary="Plate 25">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">NAVICULA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Navicula tumida (Bréb.) Cl.</td>
+            <td class="ar"><a href="#page99">99</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Navicula brasiliensis var. bicuneata Cl. forma constricta.</td>
+            <td class="ar"><a href="#page92">92</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Navicula delawarensis Grun.</td>
+            <td class="ar"><a href="#page92">92</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4-6</td>
+            <td>Navicula pusilla Wm. Sm.</td>
+            <td class="ar"><a href="#page91">91</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Navicula humerosa Bréb.</td>
+            <td class="ar"><a href="#page91">91</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Navicula spectabilis var. emarginata Cl.</td>
+            <td class="ar"><a href="#page94">94</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Navicula pusilla var. subcapitata n. var.</td>
+            <td class="ar"><a href="#page91">91</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Navicula punctulata Wm. Sm.</td>
+            <td class="ar"><a href="#page92">92</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Navicula lyra Ehr.</td>
+            <td class="ar"><a href="#page93">93</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Navicula hennedyi var. manca A. S.</td>
+            <td class="ar"><a href="#page93">93</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Navicula hennedyi Wm. Sm.</td>
+            <td class="ar"><a href="#page93">93</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Navicula lyra var. dilatata A. S.</td>
+            <td class="ar"><a href="#page93">93</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Navicula yarrensis Grun.</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Navicula yarrensis Grun. (smaller form)</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Navicula yarrensis Grun. var.?</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate25.jpg"><img
+      style="width:100%" src="images/plate25.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 25" summary="Plate 25">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">NAVICULA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Navicula tumida (Bréb.) Cl.</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Navicula brasiliensis var. bicuneata Cl. forma constricta.</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Navicula delawarensis Grun.</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4-6</td>
+      <td>Navicula pusilla Wm. Sm.</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Navicula humerosa Bréb.</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Navicula spectabilis var. emarginata Cl.</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Navicula pusilla var. subcapitata n. var.</td>
+      <td class="ar"><a href="#page91">91</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Navicula punctulata Wm. Sm.</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Navicula lyra Ehr.</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Navicula hennedyi var. manca A. S.</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Navicula hennedyi Wm. Sm.</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Navicula lyra var. dilatata A. S.</td>
+      <td class="ar"><a href="#page93">93</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Navicula yarrensis Grun.</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Navicula yarrensis Grun. (smaller form)</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Navicula yarrensis Grun. var.?</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate25.jpg"><img
+      style="width:100%" src="images/plate25.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate26"></div>
+
+  <h2>PLATE 26</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 26" summary="Plate 26">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">NAVICULA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1-2</td>
+            <td>Navicula cuspidata Kuetz.</td>
+            <td class="ar"><a href="#page100">100</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Navicula cuspidata var. ambigua (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page100">100</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Navicula spicula (Hickie) Cl.</td>
+            <td class="ar"><a href="#page100">100</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Navicula integra Wm. Sm.</td>
+            <td class="ar"><a href="#page99">99</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Navicula mutica Kuetz.</td>
+            <td class="ar"><a href="#page97">97</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Navicula americana Ehr.</td>
+            <td class="ar"><a href="#page98">98</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Navicula pupula var. bacillarioides Grun.</td>
+            <td class="ar"><a href="#page98">98</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Navicula bacillum Ehr.</td>
+            <td class="ar"><a href="#page98">98</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Navicula semen Ehr.</td>
+            <td class="ar"><a href="#page98">98</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Navicula atomus Nægeli.</td>
+            <td class="ar"><a href="#page100">100</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Navicula minima Grun.</td>
+            <td class="ar"><a href="#page98">98</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Navicula ramosissima (Ag.) Cl.</td>
+            <td class="ar"><a href="#page95">95</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Navicula crucigera (Wm. Sm.) Cl.</td>
+            <td class="ar"><a href="#page100">100</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Navicula viridula var. rostellata Kuetz.</td>
+            <td class="ar"><a href="#page95">95</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Navicula radiosa Kuetz.</td>
+            <td class="ar"><a href="#page94">94</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19</td>
+            <td>Navicula gracilis var. schizonemoides (Ehr.) V. H.</td>
+            <td class="ar"><a href="#page95">95</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Navicula peregrina Ehr.</td>
+            <td class="ar"><a href="#page94">94</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Navicula cyprinus (Wm. Sm.)</td>
+            <td class="ar"><a href="#page95">95</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Navicula reinhardtii Grun.</td>
+            <td class="ar"><a href="#page95">95</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Navicula lanceolata var. arenaria (Donk.) Cl.</td>
+            <td class="ar"><a href="#page95">95</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Navicula salinarum Grun.</td>
+            <td class="ar"><a href="#page95">95</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>25</td>
+            <td>Navicula gastrum Ehr.</td>
+            <td class="ar"><a href="#page96">96</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>26</td>
+            <td>Navicula anglica Ralfs.</td>
+            <td class="ar"><a href="#page96">96</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">DIPLONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Diploneis oculata (Bréb.) Cl.</td>
+            <td class="ar"><a href="#page86">86</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">STAURONEIS</td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Stauroneis frickei var. angusta n. var.</td>
+            <td class="ar"><a href="#page88">88</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate26.jpg"><img
+      style="width:100%" src="images/plate26.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 26" summary="Plate 26">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">NAVICULA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1-2</td>
+      <td>Navicula cuspidata Kuetz.</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Navicula cuspidata var. ambigua (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Navicula spicula (Hickie) Cl.</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Navicula integra Wm. Sm.</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Navicula mutica Kuetz.</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Navicula americana Ehr.</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Navicula pupula var. bacillarioides Grun.</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Navicula bacillum Ehr.</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Navicula semen Ehr.</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Navicula atomus Nægeli.</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Navicula minima Grun.</td>
+      <td class="ar"><a href="#page98">98</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Navicula ramosissima (Ag.) Cl.</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Navicula crucigera (Wm. Sm.) Cl.</td>
+      <td class="ar"><a href="#page100">100</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Navicula viridula var. rostellata Kuetz.</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Navicula radiosa Kuetz.</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19</td>
+      <td>Navicula gracilis var. schizonemoides (Ehr.) V. H.</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Navicula peregrina Ehr.</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Navicula cyprinus (Wm. Sm.)</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Navicula reinhardtii Grun.</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Navicula lanceolata var. arenaria (Donk.) Cl.</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Navicula salinarum Grun.</td>
+      <td class="ar"><a href="#page95">95</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>25</td>
+      <td>Navicula gastrum Ehr.</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>26</td>
+      <td>Navicula anglica Ralfs.</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">DIPLONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Diploneis oculata (Bréb.) Cl.</td>
+      <td class="ar"><a href="#page86">86</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">STAURONEIS</td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Stauroneis frickei var. angusta n. var.</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate26.jpg"><img
+      style="width:100%" src="images/plate26.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate27"></div>
+
+  <h2>PLATE 27</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 27" summary="Plate 27">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">STAURONEIS&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Stauroneis ph&#x0153;nicenteron Ehr.</td>
+            <td class="ar"><a href="#page88">88</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Stauroneis acuta Wm. Sm.</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Stauroneis americana A. S.</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Stauroneis anceps var.?</td>
+            <td class="ar"><a href="#page88">88</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Stauroneis anceps var. gracilis (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page88">88</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Stauroneis salina Wm. Sm.</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Stauroneis anceps var. amphicephala (Kuetz.) Cl.</td>
+            <td class="ar"><a href="#page88">88</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Stauroneis anceps var.?</td>
+            <td class="ar"><a href="#page88">88</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Stauroneis anceps var.?</td>
+            <td class="ar"><a href="#page88">88</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Stauroneis crucicula (Grun.) Cl.</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Stauroneis smithii Grun.</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">NAVICULA</td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Navicula lacustris Greg.</td>
+            <td class="ar"><a href="#page92">92</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Navicula hasta Pant.</td>
+            <td class="ar"><a href="#page97">97</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Navicula hasta var. punctata n. var.</td>
+            <td class="ar"><a href="#page97">97</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Navicula punctata var. asymmetrica Lagerstedt</td>
+            <td class="ar"><a href="#page92">92</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Navicula dicephala Wm. Sm.</td>
+            <td class="ar"><a href="#page96">96</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Navicula placenta Ehr.</td>
+            <td class="ar"><a href="#page94">94</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18-19</td>
+            <td>Navicula inflexa Greg.</td>
+            <td class="ar"><a href="#page96">96</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Navicula pinnata Pant.?</td>
+            <td class="ar"><a href="#page96">96</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Navicula oblonga Kuetz.</td>
+            <td class="ar"><a href="#page97">97</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Navicula pennata A. S.</td>
+            <td class="ar"><a href="#page96">96</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Navicula pygmæa Kuetz.</td>
+            <td class="ar"><a href="#page94">94</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Navicula humilis Donk.</td>
+            <td class="ar"><a href="#page96">96</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate27.jpg"><img
+      style="width:100%" src="images/plate27.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 27" summary="Plate 27">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">STAURONEIS&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Stauroneis ph&#x0153;nicenteron Ehr.</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Stauroneis acuta Wm. Sm.</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Stauroneis americana A. S.</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Stauroneis anceps var.?</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Stauroneis anceps var. gracilis (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Stauroneis salina Wm. Sm.</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Stauroneis anceps var. amphicephala (Kuetz.) Cl.</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Stauroneis anceps var.?</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Stauroneis anceps var.?</td>
+      <td class="ar"><a href="#page88">88</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Stauroneis crucicula (Grun.) Cl.</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Stauroneis smithii Grun.</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">NAVICULA</td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Navicula lacustris Greg.</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Navicula hasta Pant.</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Navicula hasta var. punctata n. var.</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Navicula punctata var. asymmetrica Lagerstedt</td>
+      <td class="ar"><a href="#page92">92</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Navicula dicephala Wm. Sm.</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Navicula placenta Ehr.</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18-19</td>
+      <td>Navicula inflexa Greg.</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Navicula pinnata Pant.?</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Navicula oblonga Kuetz.</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Navicula pennata A. S.</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Navicula pygmæa Kuetz.</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Navicula humilis Donk.</td>
+      <td class="ar"><a href="#page96">96</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate27.jpg"><img
+      style="width:100%" src="images/plate27.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate28"></div>
+
+  <h2>PLATE 28</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 28" summary="Plate 28">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">PINNULARIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Pinnularia nobilis Ehr.</td>
+            <td class="ar"><a href="#page103">103</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Pinnularia major var. pulchella n. var.</td>
+            <td class="ar"><a href="#page102">102</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Pinnularia dactylus Ehr.</td>
+            <td class="ar"><a href="#page103">103</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Pinnularia major (Kuetz.) Wm. Sm.</td>
+            <td class="ar"><a href="#page102">102</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate28.jpg"><img
+      style="width:100%" src="images/plate28.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 28" summary="Plate 28">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">PINNULARIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Pinnularia nobilis Ehr.</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Pinnularia major var. pulchella n. var.</td>
+      <td class="ar"><a href="#page102">102</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Pinnularia dactylus Ehr.</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Pinnularia major (Kuetz.) Wm. Sm.</td>
+      <td class="ar"><a href="#page102">102</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate28.jpg"><img
+      style="width:100%" src="images/plate28.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate29"></div>
+
+  <h2>PLATE 29</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 29" summary="Plate 29">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">PINNULARIA&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Pinnularia gentilis (Donk.) Cl.</td>
+            <td class="ar"><a href="#page103">103</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Pinnularia viridis Nitzsch.</td>
+            <td class="ar"><a href="#page104">104</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Pinnularia dactylus var. dariana (A. S.) Cl.</td>
+            <td class="ar"><a href="#page103">103</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Pinnularia viridis var. fallax Cl.</td>
+            <td class="ar"><a href="#page104">104</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Pinnularia socialis Palmer</td>
+            <td class="ar"><a href="#page104">104</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Pinnularia æstuarii Cl.</td>
+            <td class="ar"><a href="#page105">105</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Pinnularia rectangulata (Greg.) Cl.</td>
+            <td class="ar"><a href="#page110">110</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Pinnularia trigonocephala Cl.</td>
+            <td class="ar"><a href="#page103">103</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Pinnularia major (Kuetz.) Wm. Sm. (small form near P. viridis)</td>
+            <td class="ar"><a href="#page102">102</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Pinnularia dactylus var. demeraræ Cl.</td>
+            <td class="ar"><a href="#page103">103</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Pinnularia mormonorum (Grun.)</td>
+            <td class="ar"><a href="#page107">107</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Pinnularia brébissonii (Kuetz.) Cl.</td>
+            <td class="ar"><a href="#page107">107</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Pinnularia mesolepta Ehr.</td>
+            <td class="ar"><a href="#page105">105</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Pinnularia termes var. stauroneiformis V. H.</td>
+            <td class="ar"><a href="#page106">106</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Pinnularia molaris (Grun.) Cl.</td>
+            <td class="ar"><a href="#page105">105</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Pinnularia braunii Grun.</td>
+            <td class="ar"><a href="#page106">106</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Pinnularia termes (Ehr.) A. S.</td>
+            <td class="ar"><a href="#page106">106</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Pinnularia appendiculata (Ag.) Cl.</td>
+            <td class="ar"><a href="#page106">106</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19</td>
+            <td>Pinnularia microstauron (Ehr.) Cl. var.?</td>
+            <td class="ar"><a href="#page106">106</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Pinnularia subcapitata Greg.</td>
+            <td class="ar"><a href="#page105">105</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate29.jpg"><img
+      style="width:100%" src="images/plate29.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 29" summary="Plate 29">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">PINNULARIA&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Pinnularia gentilis (Donk.) Cl.</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Pinnularia viridis Nitzsch.</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Pinnularia dactylus var. dariana (A. S.) Cl.</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Pinnularia viridis var. fallax Cl.</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Pinnularia socialis Palmer</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Pinnularia æstuarii Cl.</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Pinnularia rectangulata (Greg.) Cl.</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Pinnularia trigonocephala Cl.</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Pinnularia major (Kuetz.) Wm. Sm. (small form near P. viridis)</td>
+      <td class="ar"><a href="#page102">102</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Pinnularia dactylus var. demeraræ Cl.</td>
+      <td class="ar"><a href="#page103">103</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Pinnularia mormonorum (Grun.)</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Pinnularia brébissonii (Kuetz.) Cl.</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Pinnularia mesolepta Ehr.</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Pinnularia termes var. stauroneiformis V. H.</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Pinnularia molaris (Grun.) Cl.</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Pinnularia braunii Grun.</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Pinnularia termes (Ehr.) A. S.</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Pinnularia appendiculata (Ag.) Cl.</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19</td>
+      <td>Pinnularia microstauron (Ehr.) Cl. var.?</td>
+      <td class="ar"><a href="#page106">106</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Pinnularia subcapitata Greg.</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate29.jpg"><img
+      style="width:100%" src="images/plate29.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate30"></div>
+
+  <h2>PLATE 30</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 30" summary="Plate 30">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">PINNULARIA&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Pinnularia cardinaliculus Cl.</td>
+            <td class="ar"><a href="#page107">107</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Pinnularia viridis var. fallax Cl.? (var. B., Wm. Sm.?).</td>
+            <td class="ar"><a href="#page104">104</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Pinnularia legumen Ehr.</td>
+            <td class="ar"><a href="#page107">107</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Pinnularia legumen var.?</td>
+            <td class="ar"><a href="#page107">107</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Pinnularia gibba (Kuetz.) V. H.</td>
+            <td class="ar"><a href="#page109">109</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Pinnularia mesogongyla (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page109">109</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Pinnularia acrosphæria (Bréb.) Cl.</td>
+            <td class="ar"><a href="#page108">108</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Pinnularia acrosphæria var. turgidula Grun.</td>
+            <td class="ar"><a href="#page108">108</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Pinnularia tabellaria (Ehr.) Cl. var.?</td>
+            <td class="ar"><a href="#page110">110</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Pinnularia leptosoma Grun.</td>
+            <td class="ar"><a href="#page105">105</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Pinnularia stauroptera var. interrupta Cl.</td>
+            <td class="ar"><a href="#page110">110</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Pinnularia stomatophora (Grun.) Cl.</td>
+            <td class="ar"><a href="#page109">109</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Pinnularia stauroptera (Grun.) Cl.</td>
+            <td class="ar"><a href="#page110">110</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Pinnularia parva (Ehr.) Cl. var.?</td>
+            <td class="ar"><a href="#page108">108</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15-19</td>
+            <td>Pinnularia nodosa forma capitata Cl.</td>
+            <td class="ar"><a href="#page108">108</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Pinnularia subcapitata var. paucistriata Grun.</td>
+            <td class="ar"><a href="#page105">105</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Pinnularia viridis Nitzsch var.</td>
+            <td class="ar"><a href="#page104">104</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Pinnularia viridis var. caudata n. var.</td>
+            <td class="ar"><a href="#page104">104</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Pinnularia mesolepta var. stauroneiformis Grun.</td>
+            <td class="ar"><a href="#page105">105</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Pinnularia polyonca (Bréb.) Lewis.</td>
+            <td class="ar"><a href="#page108">108</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Pinnularia borealis Ehr.</td>
+            <td class="ar"><a href="#page109">109</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Pinnularia lata (Bréb.) Wm. Sm.</td>
+            <td class="ar"><a href="#page109">109</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Pinnularia borealis var. scalaris (Ehr.) Cl.</td>
+            <td class="ar"><a href="#page109">109</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>25</td>
+            <td>Pinnularia blandita n. sp.</td>
+            <td class="ar"><a href="#page108">108</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate30.jpg"><img
+      style="width:100%" src="images/plate30.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 30" summary="Plate 30">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">PINNULARIA&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Pinnularia cardinaliculus Cl.</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Pinnularia viridis var. fallax Cl.? (var. B., Wm. Sm.?).</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Pinnularia legumen Ehr.</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Pinnularia legumen var.?</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Pinnularia gibba (Kuetz.) V. H.</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Pinnularia mesogongyla (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Pinnularia acrosphæria (Bréb.) Cl.</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Pinnularia acrosphæria var. turgidula Grun.</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Pinnularia tabellaria (Ehr.) Cl. var.?</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Pinnularia leptosoma Grun.</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Pinnularia stauroptera var. interrupta Cl.</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Pinnularia stomatophora (Grun.) Cl.</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Pinnularia stauroptera (Grun.) Cl.</td>
+      <td class="ar"><a href="#page110">110</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Pinnularia parva (Ehr.) Cl. var.?</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15-19</td>
+      <td>Pinnularia nodosa forma capitata Cl.</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Pinnularia subcapitata var. paucistriata Grun.</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Pinnularia viridis Nitzsch var.</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Pinnularia viridis var. caudata n. var.</td>
+      <td class="ar"><a href="#page104">104</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Pinnularia mesolepta var. stauroneiformis Grun.</td>
+      <td class="ar"><a href="#page105">105</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Pinnularia polyonca (Bréb.) Lewis.</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Pinnularia borealis Ehr.</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Pinnularia lata (Bréb.) Wm. Sm.</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Pinnularia borealis var. scalaris (Ehr.) Cl.</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>25</td>
+      <td>Pinnularia blandita n. sp.</td>
+      <td class="ar"><a href="#page108">108</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate30.jpg"><img
+      style="width:100%" src="images/plate30.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate31"></div>
+
+  <h2>PLATE 31</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 31" summary="Plate 31">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">NAVICULA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Navicula elegans Wm. Sm.</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Navicula elegans var. cuspidata Cl.</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3-4</td>
+            <td>Navicula grevillei (Ag.) Cl.</td>
+            <td class="ar"><a href="#page99">99</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Navicula libellus Greg.</td>
+            <td class="ar"><a href="#page99">99</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6-7</td>
+            <td>Navicula palpebralis Bréb.</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Navicula rhyncocephala Kuetz.</td>
+            <td class="ar"><a href="#page97">97</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Navicula cryptocephala Kuetz.</td>
+            <td class="ar"><a href="#page97">97</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Navicula longa (Greg.) Ralfs.</td>
+            <td class="ar"><a href="#page97">97</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">PINNULARIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Pinnularia brébissonii (Kuetz.) Cl.</td>
+            <td class="ar"><a href="#page107">107</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Pinnularia borealis Ehr.</td>
+            <td class="ar"><a href="#page109">109</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Pinnularia divergens var. elliptica Grun.</td>
+            <td class="ar"><a href="#page107">107</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">EPITHEMIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Epithemia turgida (Ehr.) Kuetz.</td>
+            <td class="ar"><a href="#page111">111</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15-21</td>
+            <td>Epithemia argus Kuetz.</td>
+            <td class="ar"><a href="#page111">111</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Epithemia argus var.?</td>
+            <td class="ar"><a href="#page111">111</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Epithemia muelleri A. S.</td>
+            <td class="ar"><a href="#page111">111</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Epithemia zebra var. proboscidea (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page112">112</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19</td>
+            <td>Epithemia gibberula var. producta Grun.</td>
+            <td class="ar"><a href="#page112">112</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Epithemia musculus Kuetz.</td>
+            <td class="ar"><a href="#page112">112</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Epithemia musculus var. constricta (Bréb.) V. H.</td>
+            <td class="ar"><a href="#page112">112</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">RHOPALODIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Rhopalodia gibba (Kuetz.) Mueller</td>
+            <td class="ar"><a href="#page112">112</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Rhopalodia ventricosa (Kuetz.) Mueller</td>
+            <td class="ar"><a href="#page113">113</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate31.jpg"><img
+      style="width:100%" src="images/plate31.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 31" summary="Plate 31">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">NAVICULA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Navicula elegans Wm. Sm.</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Navicula elegans var. cuspidata Cl.</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3-4</td>
+      <td>Navicula grevillei (Ag.) Cl.</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Navicula libellus Greg.</td>
+      <td class="ar"><a href="#page99">99</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6-7</td>
+      <td>Navicula palpebralis Bréb.</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Navicula rhyncocephala Kuetz.</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Navicula cryptocephala Kuetz.</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Navicula longa (Greg.) Ralfs.</td>
+      <td class="ar"><a href="#page97">97</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">PINNULARIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Pinnularia brébissonii (Kuetz.) Cl.</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Pinnularia borealis Ehr.</td>
+      <td class="ar"><a href="#page109">109</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Pinnularia divergens var. elliptica Grun.</td>
+      <td class="ar"><a href="#page107">107</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">EPITHEMIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Epithemia turgida (Ehr.) Kuetz.</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15-21</td>
+      <td>Epithemia argus Kuetz.</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Epithemia argus var.?</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Epithemia muelleri A. S.</td>
+      <td class="ar"><a href="#page111">111</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Epithemia zebra var. proboscidea (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19</td>
+      <td>Epithemia gibberula var. producta Grun.</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Epithemia musculus Kuetz.</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Epithemia musculus var. constricta (Bréb.) V. H.</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">RHOPALODIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Rhopalodia gibba (Kuetz.) Mueller</td>
+      <td class="ar"><a href="#page112">112</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Rhopalodia ventricosa (Kuetz.) Mueller</td>
+      <td class="ar"><a href="#page113">113</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate31.jpg"><img
+      style="width:100%" src="images/plate31.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate32"></div>
+
+  <h2>PLATE 32</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 32" summary="Plate 32">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">NITZSCHIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Nitzschia circumsuta (Bail.) Grun.</td>
+            <td class="ar"><a href="#page118">118</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Nitzschia plana Wm. Sm.</td>
+            <td class="ar"><a href="#page117">117</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Nitzschia granulata Grun.</td>
+            <td class="ar"><a href="#page116">116</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Nitzschia navicularis (Bréb.) Grun.</td>
+            <td class="ar"><a href="#page116">116</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Nitzschia panduriformis var. minor Grun.</td>
+            <td class="ar"><a href="#page117">117</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Nitzschia apiculata (Greg.) Grun.</td>
+            <td class="ar"><a href="#page117">117</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Nitzschia tabellaria Grun.</td>
+            <td class="ar"><a href="#page119">119</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Nitzschia tryblionella Hantzsch</td>
+            <td class="ar"><a href="#page116">116</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10-11</td>
+            <td>Nitzschia bilobata Wm. Sm.</td>
+            <td class="ar"><a href="#page118">118</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Nitzschia litoralis var. delawarensis Grun.</td>
+            <td class="ar"><a href="#page118">118</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Nitzschia acuminata (Wm. Sm.) Grun.</td>
+            <td class="ar"><a href="#page117">117</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14-25</td>
+            <td>Nitzschia amphibia Grun.</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Nitzschia palea (Kuetz.) Wm. Sm.</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Nitzschia fluminensis Grun.</td>
+            <td class="ar"><a href="#page120">120</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Nitzschia obtusa var. scalpelliformis Grun.</td>
+            <td class="ar"><a href="#page121">121</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18</td>
+            <td>Nitzschia linearis (Ag.) Wm. Sm.</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>19</td>
+            <td>Nitzschia communis Rab.</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Nitzschia clausii Hantzsch.</td>
+            <td class="ar"><a href="#page121">121</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Nitzschia epithemioides Grun.</td>
+            <td class="ar"><a href="#page118">118</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>24</td>
+            <td>Nitzschia vermicularis (Kuetz.) Wm. Sm.</td>
+            <td class="ar"><a href="#page120">120</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">HANTZSCHIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Hantzschia amphioxys (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page113">113</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Hantzschia marina (Donk.) Grun.</td>
+            <td class="ar"><a href="#page114">114</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Hantzschia virgata (Roper) Grun.</td>
+            <td class="ar"><a href="#page114">114</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate32.jpg"><img
+      style="width:100%" src="images/plate32.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 32" summary="Plate 32">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">NITZSCHIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Nitzschia circumsuta (Bail.) Grun.</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Nitzschia plana Wm. Sm.</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Nitzschia granulata Grun.</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Nitzschia navicularis (Bréb.) Grun.</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Nitzschia panduriformis var. minor Grun.</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Nitzschia apiculata (Greg.) Grun.</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Nitzschia tabellaria Grun.</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Nitzschia tryblionella Hantzsch</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10-11</td>
+      <td>Nitzschia bilobata Wm. Sm.</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Nitzschia litoralis var. delawarensis Grun.</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Nitzschia acuminata (Wm. Sm.) Grun.</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14-25</td>
+      <td>Nitzschia amphibia Grun.</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Nitzschia palea (Kuetz.) Wm. Sm.</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Nitzschia fluminensis Grun.</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Nitzschia obtusa var. scalpelliformis Grun.</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18</td>
+      <td>Nitzschia linearis (Ag.) Wm. Sm.</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>19</td>
+      <td>Nitzschia communis Rab.</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Nitzschia clausii Hantzsch.</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Nitzschia epithemioides Grun.</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>24</td>
+      <td>Nitzschia vermicularis (Kuetz.) Wm. Sm.</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">HANTZSCHIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Hantzschia amphioxys (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page113">113</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Hantzschia marina (Donk.) Grun.</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Hantzschia virgata (Roper) Grun.</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate32.jpg"><img
+      style="width:100%" src="images/plate32.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate33"></div>
+
+  <h2>PLATE 33</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 33" summary="Plate 33">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">NITZSCHIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Nitzschia longissima (Bréb.) Ralfs</td>
+            <td class="ar"><a href="#page123">123</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Nitzschia intermedia Hantzsch</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Nitzschia spectabilis var. americana Grun.</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4-5</td>
+            <td>Nitzschia sigmatella Greg.</td>
+            <td class="ar"><a href="#page121">121</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Nitzschia scalaris (Ehr.) Wm. Sm.</td>
+            <td class="ar"><a href="#page119">119</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Nitzschia macilenta Greg.</td>
+            <td class="ar"><a href="#page120">120</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Nitzschia insignis Greg.</td>
+            <td class="ar"><a href="#page119">119</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Nitzschia vermicularis (Kuetz.) Hantzsch</td>
+            <td class="ar"><a href="#page120">120</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Nitzschia longissima forma parva V. H.</td>
+            <td class="ar"><a href="#page123">123</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Nitzschia reversa Wm. Sm.</td>
+            <td class="ar"><a href="#page123">123</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Nitzschia acicularis (Kuetz.) Wm. Sm.</td>
+            <td class="ar"><a href="#page123">123</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13-14</td>
+            <td>Nitzschia paxillifer (O. F. Mueller) Heib.</td>
+            <td class="ar"><a href="#page119">119</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">HOM&#x0152;OCLADIA</td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Hom&#x0153;ocladia filiformis Wm. Sm.</td>
+            <td class="ar"><a href="#page123">123</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate33.jpg"><img
+      style="width:100%" src="images/plate33.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 33" summary="Plate 33">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">NITZSCHIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Nitzschia longissima (Bréb.) Ralfs</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Nitzschia intermedia Hantzsch</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Nitzschia spectabilis var. americana Grun.</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4-5</td>
+      <td>Nitzschia sigmatella Greg.</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Nitzschia scalaris (Ehr.) Wm. Sm.</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Nitzschia macilenta Greg.</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Nitzschia insignis Greg.</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Nitzschia vermicularis (Kuetz.) Hantzsch</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Nitzschia longissima forma parva V. H.</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Nitzschia reversa Wm. Sm.</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Nitzschia acicularis (Kuetz.) Wm. Sm.</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13-14</td>
+      <td>Nitzschia paxillifer (O. F. Mueller) Heib.</td>
+      <td class="ar"><a href="#page119">119</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">HOM&#x0152;OCLADIA</td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Hom&#x0153;ocladia filiformis Wm. Sm.</td>
+      <td class="ar"><a href="#page123">123</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate33.jpg"><img
+      style="width:100%" src="images/plate33.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate34"></div>
+
+  <h2>PLATE 34</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 34" summary="Plate 34">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">SURIRELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Surirella striatula Turpin</td>
+            <td class="ar"><a href="#page125">125</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Surirella anceps Lewis</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Surirella intermedia Lewis</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Surirella arctissima A. S.</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5-6</td>
+            <td>Surirella delicatissima Lewis</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Surirella intermedia Lewis forma minor?</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">CYMATOPLEURA</td>
+          </tr>
+          <tr class="pb05">
+            <td>8-9</td>
+            <td>Cymatopleura solea (Bréb.) Wm. Sm.</td>
+            <td class="ar"><a href="#page129">129</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate34.jpg"><img
+      style="width:100%" src="images/plate34.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 34" summary="Plate 34">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">SURIRELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Surirella striatula Turpin</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Surirella anceps Lewis</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Surirella intermedia Lewis</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Surirella arctissima A. S.</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5-6</td>
+      <td>Surirella delicatissima Lewis</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Surirella intermedia Lewis forma minor?</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">CYMATOPLEURA</td>
+    </tr>
+    <tr class="pb05">
+      <td>8-9</td>
+      <td>Cymatopleura solea (Bréb.) Wm. Sm.</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate34.jpg"><img
+      style="width:100%" src="images/plate34.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate35"></div>
+
+  <h2>PLATE 35</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 35" summary="Plate 35">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">SURIRELLA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Surirella fastuosa Ehr.</td>
+            <td class="ar"><a href="#page127">127</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Surirella biseriata (Ehr.) Bréb.</td>
+            <td class="ar"><a href="#page124">124</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Surirella splendida (Ehr.) Kuetz.</td>
+            <td class="ar"><a href="#page125">125</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Surirella crumena Bréb.</td>
+            <td class="ar"><a href="#page126">126</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Surirella ovalis Bréb.</td>
+            <td class="ar"><a href="#page126">126</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Surirella tenera Greg.</td>
+            <td class="ar"><a href="#page125">125</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Surirella recedens A. S.</td>
+            <td class="ar"><a href="#page127">127</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Surirella linearis Wm. Sm.</td>
+            <td class="ar"><a href="#page124">124</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Surirella oblonga Ehr.?</td>
+            <td class="ar"><a href="#page127">127</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Surirella cruciata A. S.</td>
+            <td class="ar"><a href="#page127">127</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Surirella gracilis Grun.</td>
+            <td class="ar"><a href="#page127">127</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12-13</td>
+            <td>Surirella amphioxys Wm. Sm.</td>
+            <td class="ar"><a href="#page124">124</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate35.jpg"><img
+      style="width:100%" src="images/plate35.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 35" summary="Plate 35">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">SURIRELLA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Surirella fastuosa Ehr.</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Surirella biseriata (Ehr.) Bréb.</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Surirella splendida (Ehr.) Kuetz.</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Surirella crumena Bréb.</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Surirella ovalis Bréb.</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Surirella tenera Greg.</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Surirella recedens A. S.</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Surirella linearis Wm. Sm.</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Surirella oblonga Ehr.?</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Surirella cruciata A. S.</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Surirella gracilis Grun.</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12-13</td>
+      <td>Surirella amphioxys Wm. Sm.</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate35.jpg"><img
+      style="width:100%" src="images/plate35.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate36"></div>
+
+  <h2>PLATE 36</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 36" summary="Plate 36">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">SURIRELLA&mdash;Continued</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Surirella elegans Ehr.</td>
+            <td class="ar"><a href="#page125">125</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Surirella robusta Ehr.</td>
+            <td class="ar"><a href="#page124">124</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Surirella febigerii Lewis</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Surirella gemma Ehr.</td>
+            <td class="ar"><a href="#page125">125</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Surirella guatimalensis Ehr.</td>
+            <td class="ar"><a href="#page126">126</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Surirella panduriformis Wm. Sm.</td>
+            <td class="ar"><a href="#page126">126</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7-9</td>
+            <td>Surirella pinnata Wm. Sm.</td>
+            <td class="ar"><a href="#page126">126</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Surirella angusta Kuetz.</td>
+            <td class="ar"><a href="#page127">127</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate36.jpg"><img
+      style="width:100%" src="images/plate36.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 36" summary="Plate 36">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">SURIRELLA&mdash;Continued</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Surirella elegans Ehr.</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Surirella robusta Ehr.</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Surirella febigerii Lewis</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Surirella gemma Ehr.</td>
+      <td class="ar"><a href="#page125">125</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Surirella guatimalensis Ehr.</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Surirella panduriformis Wm. Sm.</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7-9</td>
+      <td>Surirella pinnata Wm. Sm.</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Surirella angusta Kuetz.</td>
+      <td class="ar"><a href="#page127">127</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate36.jpg"><img
+      style="width:100%" src="images/plate36.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate37"></div>
+
+  <h2>PLATE 37</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 37" summary="Plate 37">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac">CYMATOPLEURA</td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Cymatopleura elliptica (Bréb.) Wm. Sm.</td>
+            <td class="ar"><a href="#page129">129</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Cymatopleura elliptica forma spiralis</td>
+            <td class="ar"><a href="#page129">129</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3-4</td>
+            <td>Cymatopleura marina Lewis</td>
+            <td class="ar"><a href="#page129">129</a></td>
+          </tr>
+          <tr class="pb05">
+            <td colspan="3" class="ac pt05">CAMPYLODISCUS</td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Campylodiscus hibernicus Ehr.</td>
+            <td class="ar"><a href="#page130">130</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Campylodiscus echeneis Ehr.</td>
+            <td class="ar"><a href="#page130">130</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate37.jpg"><img
+      style="width:100%" src="images/plate37.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 37" summary="Plate 37">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac">CYMATOPLEURA</td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Cymatopleura elliptica (Bréb.) Wm. Sm.</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Cymatopleura elliptica forma spiralis</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3-4</td>
+      <td>Cymatopleura marina Lewis</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr class="pb05">
+      <td colspan="3" class="ac pt05">CAMPYLODISCUS</td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Campylodiscus hibernicus Ehr.</td>
+      <td class="ar"><a href="#page130">130</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Campylodiscus echeneis Ehr.</td>
+      <td class="ar"><a href="#page130">130</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate37.jpg"><img
+      style="width:100%" src="images/plate37.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate38"></div>
+
+  <h2>PLATE 38</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 38" summary="Plate 38">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Amphora gigantea var. fusca A. S.</td>
+            <td class="ar"><a href="#page65">65</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Meloseira crenulata (Ehr.) Kuetz.</td>
+            <td class="ar"><a href="#page15">15</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3-4</td>
+            <td>Licmophora baileyi (Edw.) Grun.</td>
+            <td class="ar"><a href="#page40">40</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Coscinodiscus polyacanthus Grun.</td>
+            <td class="ar"><a href="#page22">22</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6-7</td>
+            <td>Ditylum intricatum (West) Grun.</td>
+            <td class="ar"><a href="#page30">30</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Pyxidicula cruciata Ehr.</td>
+            <td class="ar"><a href="#page19">19</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Gyrosigma scalproides (Rab.) Cl.</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Coscinodiscus asteromphalus var. omphalantha (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Rhabdonema minutum Kuetz.</td>
+            <td class="ar"><a href="#page36">36</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Gyrosigma kuetzingii (Grun.) Cl.</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Gyrosigma prolongatum (Wm. Sm.) Cl.</td>
+            <td class="ar"><a href="#page76">76</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Cymbella parva (Wm. Sm.) Cl.</td>
+            <td class="ar"><a href="#page61">61</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Gomphoneis herculaneum (Ehr.) Cl. (zone view)</td>
+            <td class="ar"><a href="#page70">70</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Cymbella ventricosa Kuetz.</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17-18</td>
+            <td>Eunotia sp. (abnormal?)</td>
+            <td class="ar"><a href="#page54">54</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate38.jpg"><img
+      style="width:100%" src="images/plate38.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 38" summary="Plate 38">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Amphora gigantea var. fusca A. S.</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Meloseira crenulata (Ehr.) Kuetz.</td>
+      <td class="ar"><a href="#page15">15</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3-4</td>
+      <td>Licmophora baileyi (Edw.) Grun.</td>
+      <td class="ar"><a href="#page40">40</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Coscinodiscus polyacanthus Grun.</td>
+      <td class="ar"><a href="#page22">22</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6-7</td>
+      <td>Ditylum intricatum (West) Grun.</td>
+      <td class="ar"><a href="#page30">30</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Pyxidicula cruciata Ehr.</td>
+      <td class="ar"><a href="#page19">19</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Gyrosigma scalproides (Rab.) Cl.</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Coscinodiscus asteromphalus var. omphalantha (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Rhabdonema minutum Kuetz.</td>
+      <td class="ar"><a href="#page36">36</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Gyrosigma kuetzingii (Grun.) Cl.</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Gyrosigma prolongatum (Wm. Sm.) Cl.</td>
+      <td class="ar"><a href="#page76">76</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Cymbella parva (Wm. Sm.) Cl.</td>
+      <td class="ar"><a href="#page61">61</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Gomphoneis herculaneum (Ehr.) Cl. (zone view)</td>
+      <td class="ar"><a href="#page70">70</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Cymbella ventricosa Kuetz.</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17-18</td>
+      <td>Eunotia sp. (abnormal?)</td>
+      <td class="ar"><a href="#page54">54</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate38.jpg"><img
+      style="width:100%" src="images/plate38.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate39"></div>
+
+  <h2>PLATE 39</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 39" summary="Plate 39">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Nitzschia spectabilis var. americana Grun. (zone view)</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Nitzschia panduriformis Greg.</td>
+            <td class="ar"><a href="#page117">117</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Hantzschia amphioxys (Ehr.) Grun.</td>
+            <td class="ar"><a href="#page113">113</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Hantzschia amphioxys var. major Grun.</td>
+            <td class="ar"><a href="#page114">114</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Nitzschia dubia Wm. Sm.</td>
+            <td class="ar"><a href="#page118">118</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Nitzschia amphioxys Wm. Sm.</td>
+            <td class="ar"><a href="#page114">114</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Nitzschia compressa (Bail.)</td>
+            <td class="ar"><a href="#page116">116</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Nitzschia compressa var. minor H. L. Smith</td>
+            <td class="ar"><a href="#page116">116</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Surirella intermedia Lewis (zone view)</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Surirella arctissima A. S. forma minor</td>
+            <td class="ar"><a href="#page128">128</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Surirella ovalis Bréb.</td>
+            <td class="ar"><a href="#page126">126</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Surirella biseriata (Ehr.) Bréb.</td>
+            <td class="ar"><a href="#page124">124</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13</td>
+            <td>Nitzschia sigma (Kuetz.) Wm. Sm.</td>
+            <td class="ar"><a href="#page121">121</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>14</td>
+            <td>Nitzschia obtusa var. flexella H. L. Smith</td>
+            <td class="ar"><a href="#page121">121</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>15</td>
+            <td>Stauroneis legumen Ehr.</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Nitzschia obtusa Wm. Sm.</td>
+            <td class="ar"><a href="#page121">121</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate39.jpg"><img
+      style="width:100%" src="images/plate39.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="sp3 w100 smaller handonly" title="Plate 39" summary="Plate 39">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Nitzschia spectabilis var. americana Grun. (zone view)</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Nitzschia panduriformis Greg.</td>
+      <td class="ar"><a href="#page117">117</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Hantzschia amphioxys (Ehr.) Grun.</td>
+      <td class="ar"><a href="#page113">113</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Hantzschia amphioxys var. major Grun.</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Nitzschia dubia Wm. Sm.</td>
+      <td class="ar"><a href="#page118">118</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Nitzschia amphioxys Wm. Sm.</td>
+      <td class="ar"><a href="#page114">114</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Nitzschia compressa (Bail.)</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Nitzschia compressa var. minor H. L. Smith</td>
+      <td class="ar"><a href="#page116">116</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Surirella intermedia Lewis (zone view)</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Surirella arctissima A. S. forma minor</td>
+      <td class="ar"><a href="#page128">128</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Surirella ovalis Bréb.</td>
+      <td class="ar"><a href="#page126">126</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Surirella biseriata (Ehr.) Bréb.</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13</td>
+      <td>Nitzschia sigma (Kuetz.) Wm. Sm.</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>14</td>
+      <td>Nitzschia obtusa var. flexella H. L. Smith</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>15</td>
+      <td>Stauroneis legumen Ehr.</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Nitzschia obtusa Wm. Sm.</td>
+      <td class="ar"><a href="#page121">121</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate39.jpg"><img
+      style="width:100%" src="images/plate39.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <div id="plate40"></div>
+
+  <h2>PLATE 40</h2>
+
+  <table class="sp3 mc w100 nothand" title="Plate" summary="Plate">
+    <tr>
+      <td class="w50 vmi pr2" style="padding:0">
+        <table class="w100" title="Plate 40" summary="Plate 40">
+          <tr>
+            <td><span class="sc">Fig.</span></td>
+            <td></td>
+            <td class="ar"><span class="sc">Page</span></td>
+          </tr>
+          <tr class="pb05">
+            <td>1</td>
+            <td>Caloneis liber (Wm. Sm.) Cl.</td>
+            <td class="ar"><a href="#page81">81</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>2</td>
+            <td>Anom&#x0153;oneis sphærophora (Kuetz.) Cl.</td>
+            <td class="ar"><a href="#page80">80</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>3</td>
+            <td>Nitzschia spathulata Bréb.</td>
+            <td class="ar"><a href="#page120">120</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>4</td>
+            <td>Stauroneis ? abnormal</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>5</td>
+            <td>Navicula ? abnormal</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>6</td>
+            <td>Podocystis adriatica Kuetz.</td>
+            <td class="ar"><a href="#page129">129</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>7</td>
+            <td>Nitzschia dissipata (Kuetz.) Grun.</td>
+            <td class="ar"><a href="#page120">120</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>8</td>
+            <td>Cymbella ventricosa Kuetz. (zone view)</td>
+            <td class="ar"><a href="#page62">62</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>9</td>
+            <td>Navicula radiosa Kuetz. (zone view)</td>
+            <td class="ar"><a href="#page94">94</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>10</td>
+            <td>Detail of Rhabdonema arcuatum (Lyng.) Kuetz.</td>
+            <td class="ar"><a href="#page35">35</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>11</td>
+            <td>Diatoma anceps (Ehr.) Kirchn. (containing chromataphores)</td>
+            <td class="ar"><a href="#page42">42</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>12</td>
+            <td>Coscinodiscus asteromphalus Ehr. (trans. section, after Pelletan)</td>
+            <td class="ar"><a href="#page23">23</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>13-14-15</td>
+            <td>Transverse section (diagram) of Pinnularia showing straight, oblique and grooved
+            raphes</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>16</td>
+            <td>Transverse section (diagram) of Biddulphia favus showing inner punctate stratum
+            (after Deby)</td>
+            <td class="ar"><a href="#page31">31</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>17</td>
+            <td>Transverse (ideal) section of Surirella</td>
+            <td class="ar"><a href="#page124">124</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>18-19</td>
+            <td>Transverse (ideal) section of Pinnularia, before and after division</td>
+            <td class="ar"><a href="#page101">101</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>20</td>
+            <td>Transverse section of Nitzschia linearis (Ag.) Wm. Sm.</td>
+            <td class="ar"><a href="#page122">122</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>21</td>
+            <td>Transverse section (diagram) of Navicula</td>
+            <td class="ar"><a href="#page89">89</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>22</td>
+            <td>Transverse section (diagram) of Cymbella</td>
+            <td class="ar"><a href="#page60">60</a></td>
+          </tr>
+          <tr class="pb05">
+            <td>23</td>
+            <td>Transverse section (diagram) of Amphora</td>
+            <td class="ar"><a href="#page65">65</a></td>
+          </tr>
+        </table>
+      </td>
+      <td class="w50 vmi"><span class="ac w100 fcenter"><a href="images/plate40.jpg"><img
+      style="width:100%" src="images/plate40.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+  <table class="w100 smaller handonly" title="Plate 40" summary="Plate 40">
+    <tr>
+      <td><span class="sc">Fig.</span></td>
+      <td></td>
+      <td class="ar"><span class="sc">Page</span></td>
+    </tr>
+    <tr class="pb05">
+      <td>1</td>
+      <td>Caloneis liber (Wm. Sm.) Cl.</td>
+      <td class="ar"><a href="#page81">81</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>2</td>
+      <td>Anom&#x0153;oneis sphærophora (Kuetz.) Cl.</td>
+      <td class="ar"><a href="#page80">80</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>3</td>
+      <td>Nitzschia spathulata Bréb.</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>4</td>
+      <td>Stauroneis ? abnormal</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>5</td>
+      <td>Navicula ? abnormal</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>6</td>
+      <td>Podocystis adriatica Kuetz.</td>
+      <td class="ar"><a href="#page129">129</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>7</td>
+      <td>Nitzschia dissipata (Kuetz.) Grun.</td>
+      <td class="ar"><a href="#page120">120</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>8</td>
+      <td>Cymbella ventricosa Kuetz. (zone view)</td>
+      <td class="ar"><a href="#page62">62</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>9</td>
+      <td>Navicula radiosa Kuetz. (zone view)</td>
+      <td class="ar"><a href="#page94">94</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>10</td>
+      <td>Detail of Rhabdonema arcuatum (Lyng.) Kuetz.</td>
+      <td class="ar"><a href="#page35">35</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>11</td>
+      <td>Diatoma anceps (Ehr.) Kirchn. (containing chromataphores)</td>
+      <td class="ar"><a href="#page42">42</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>12</td>
+      <td>Coscinodiscus asteromphalus Ehr. (trans. section, after Pelletan)</td>
+      <td class="ar"><a href="#page23">23</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>13-14-15</td>
+      <td>Transverse section (diagram) of Pinnularia showing straight, oblique and grooved
+      raphes</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>16</td>
+      <td>Transverse section (diagram) of Biddulphia favus showing inner punctate stratum (after
+      Deby)</td>
+      <td class="ar"><a href="#page31">31</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>17</td>
+      <td>Transverse (ideal) section of Surirella</td>
+      <td class="ar"><a href="#page124">124</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>18-19</td>
+      <td>Transverse (ideal) section of Pinnularia, before and after division</td>
+      <td class="ar"><a href="#page101">101</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>20</td>
+      <td>Transverse section of Nitzschia linearis (Ag.) Wm. Sm.</td>
+      <td class="ar"><a href="#page122">122</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>21</td>
+      <td>Transverse section (diagram) of Navicula</td>
+      <td class="ar"><a href="#page89">89</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>22</td>
+      <td>Transverse section (diagram) of Cymbella</td>
+      <td class="ar"><a href="#page60">60</a></td>
+    </tr>
+    <tr class="pb05">
+      <td>23</td>
+      <td>Transverse section (diagram) of Amphora</td>
+      <td class="ar"><a href="#page65">65</a></td>
+    </tr>
+    <tr>
+      <td colspan="3"><span class="ac w100 fcenter"><a href="images/plate40.jpg"><img
+      style="width:100%" src="images/plate40.jpg" alt="" title=""/></a></span></td>
+    </tr>
+  </table>
+
+
+
+
+
+
+
+
+<pre>
+
+
+
+
+
+End of the Project Gutenberg EBook of The Diatomaceae of Philadelphia and
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+</pre>
+
+</body>
+</html>
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+The Project Gutenberg EBook of The Diatomaceae of Philadelphia and Vicinity, by 
+Charles Sumner Boyer
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+Title: The Diatomaceae of Philadelphia and Vicinity
+
+Author: Charles Sumner Boyer
+
+Release Date: January 3, 2014 [EBook #44569]
+
+Language: English
+
+Character set encoding: ASCII
+
+*** START OF THIS PROJECT GUTENBERG EBOOK DIATOMACEAE ***
+
+
+
+
+Produced by Charlene Taylor, Bryan Ness, Keith Edkins and
+the Online Distributed Proofreading Team at
+http://www.pgdp.net (This file was produced from images
+generously made available by The Internet Archive)
+
+
+
+
+
+Transcriber's note: Text enclosed by underscores is in italics (_italics_).
+      Page numbers enclosed by curly braces (example: {25}) have been
+      incorporated to facilitate the use of the Index.
+
+Images of the original pages are available through Internet Archive. See
+      https://archive.org/details/diatomaceofphi00boye
+
+       *       *       *       *       *
+
+[Illustration: DUCK POND, CORNER OF FOURTH AND MARKET STREETS (ABOUT 1700)]
+
+
+
+
+THE DIATOMACEAE OF
+PHILADELPHIA AND VICINITY
+
+
+BY
+
+CHARLES S. BOYER, A.M., F.R.M.S.
+
+
+_ILLUSTRATED WITH SEVEN HUNDRED
+DRAWINGS BY THE AUTHOR_
+
+
+PRESS OF
+
+J. B. LIPPINCOTT COMPANY
+
+EAST WASHINGTON SQUARE PHILADELPHIA
+
+1916
+
+
+
+
+PREFACE
+
+
+The present contribution to the local flora is intended as an introduction
+to more extended research.
+
+The study is of advantage in relation to the life history of aquatic
+animals, the determination of ocean currents, as proved by polar
+discoveries, the investigation of geological strata where other fossil
+forms are absent, and the analysis of water supply; and, when we consider
+the universal distribution of diatomaceae in the earth, the water and even
+in the air and the enormous deposits formed in past ages and still forming,
+we are able to realize the importance of a knowledge of these complicated
+forms and their function of purification.
+
+The absence of descriptive works of reference in available form in this
+country, the polyglot confusion of authorities abroad and the amount of
+time, patience and skill required in obtaining, preparing and examining
+specimens, render the study one of difficulty.
+
+The bibliography is omitted, as it is understood by those who possess the
+works of reference, and but few synonyms are given, having but little,
+except historical, value, especially when it is considered that modern
+investigators have no access to many of the earlier collections, when any
+of these exist.
+
+So far as the marine forms are concerned, it is probable that nearly all
+occurring north of Florida are here included, and the fresh-water species
+described represent a large proportion of those found east of the
+Alleghanies. All of the figures are drawn to the same scale, a
+magnification of eight hundred diameters, from specimens in my possession,
+nearly all of which were found in or near Philadelphia.
+
+If the work is of any value in inducing further investigation, I hope, in
+the words of Julien Deby, that "those who follow my advice will find in the
+study of these wonderful little organisms as much pleasure as I myself have
+found."
+
+  THE AUTHOR.
+
+
+
+
+{5}INTRODUCTION
+
+
+The Delaware River rises in the Western Catskill Mountains, flows southward
+for about three hundred and seventy-five miles, and expands into Delaware
+Bay about sixty miles from the sea. Its origin is among the Devonian and
+Carboniferous rocks, and in its course it passes through Silurian, Triassic
+and Cretaceous formations, finally reaching the Cambrian and Laurentian
+beds. It also drains regions of the glacial drift and beds which overlie
+overturned Miocene strata, and are sometimes mixed with them. From the
+mountains, nearly four thousand feet high, to the Bay, where the depth of
+water is not greater than seventy-five feet, the diatomaceous flora, from
+Alpine cascades to the salt marshes of New Jersey, contains a larger number
+of species than any other equal portion of the American coast.
+
+The city of Philadelphia, about one hundred miles from the sea, lies at the
+junction of the Schuylkill with the Delaware, and much of the land near the
+rivers, especially southward, is flat and low, composed of recent alluvial
+deposits. In the central districts the ground is high, the deep sub-soil
+being mostly a dry gravel resting upon gneiss and schist, although it is in
+part composed of a bluish clay which was probably laid down in the bed of
+the ancient river before the last period of the glacial drift. The blue
+clay was not all deposited at the same time, as in the lower strata many
+marine forms are found which do not occur in the upper layers. This is
+notably the case in a deposit obtained at Spreckel's Sugar Refinery and
+also at the east end of Walnut Street Bridge, where a layer of blue clay
+occurs which is overlain by glacial drift. In other parts of the city
+mixtures of blue clay with more recent deposits are found, including
+fresh-water forms from numerous creeks and rivulets which traversed what is
+now the city proper, and especially from the vicinity of Fourth and Market
+Streets, where there existed as late as the year 1700 a large pond known as
+the "Duck Pond" which was subject to tidal overflow from its outlet, Dock
+Creek. The river water at Philadelphia is not noticeably brackish, although
+the tide extends thirty miles above the city and, before the building of
+Fairmount Dam, to the Falls of the Schuylkill. At certain times, when the
+river is low, the influx of tide water is sufficient to produce an
+abundance of brackish water diatoms at Greenwich Point. The entire absence,
+however, at present, of many of the marine forms obtained in dredgings in
+the Delaware opposite the city, as at Smith's Island, now removed, and in
+certain well borings at Pavonia, Pensauken, Gloucester and other places in
+New Jersey, where the depth reached the old blue clay, indicates conditions
+quite different from those now prevalent. In the Bay itself comparatively
+few living species are found, at least in any abundance.
+
+In the study of local forms which follows, the district included may be
+considered as circumscribed by the circumference of a circle having a
+radius of one hundred miles from Philadelphia, containing the States of New
+Jersey and Delaware, the southeastern part of {6}Pennsylvania, a portion of
+Maryland on the south and extending eastward to New York Bay and Long
+Island Sound as far as New Rochelle.
+
+The greater number of fresh-water species described have been obtained from
+near the city along the Darby, Crum, Ridley and Brandywine Creeks and from
+various places in New Jersey, including the Pine Barren region of the
+southern part of the State. Numerous collections have been made in the
+Schuylkill and the various reservoirs and along the Wissahickon, "where an
+Alpine gorge in miniature of singular loveliness is to be found within the
+limits of a city." The fossil deposits are from well borings near Camden,
+N. J., and from excavations in various parts of the city.
+
+There appears to be no relation between the Miocene beds of the eastern
+coast and the deposits here described, all of which have been formed later
+than the glacial period or in an interval between two such periods.
+Apparently no diatoms grew during the glacial era, at least in sufficient
+abundance to leave any perceptible traces of their existence. An
+examination of glacial "flour" and clays from the Catskills shows an entire
+absence of these forms, and I have never found them in the milky flow from
+the glaciers of the Alps nor in the constantly muddy streams in certain of
+our Western States. The opacity of the water produces the same result as
+the absence of light in the deep lakes of New England, where diatoms are
+found only on the stalks or roots of water-plants near the shore, while in
+shallow ponds, such as the small lake near the summit of Mt. Lafayette, the
+growth is abundant. Certain species will grow wherever there are moisture,
+light and heat, but the greater number require the presence, in small
+amounts, of substances produced by the decay of animal and vegetable life.
+An abundance of diatoms in fresh water is usually an indication of its
+potability, while their entire absence in shallow water may be due to an
+excess of bacteria.
+
+The specimens from which the drawings are made have been collected by the
+author for many years; in addition to possessing an almost complete library
+on the subject, he has had the advantage of examining material obtained by
+the late Mr. Lewis Woolman and numerous slides furnished by a number of
+friends, including Mr. John A. Shulze, Mr. Frank J. Keeley and Mr. T.
+Chalkley Palmer, to whom I here take pleasure in expressing my thanks.
+
+The difficulties of the study are well stated by Agardh in the following
+extract from the preface to his Systema Algarum:
+
+"Because, indeed, in this respect, no one will wonder whether in the
+distinction of species and reference to synonyms we have, perchance,
+committed many errors. They have occurred and are bound to occur, partly
+from the fact that one is not permitted to see the original specimens of
+all authors; partly, because sometimes even the original specimens of these
+plants are erroneous; partly, because the figures and descriptions of
+authors are often lacking and imperfect....
+
+"There is added the difficulty of the study itself of these plants, their
+submerged habitat, the minuteness of their structure, the rarity of their
+fruit, the change in the dried {7}plant, the impossibility of culture, the
+fallacies of microscopical vision and the chaotic condition of Algology
+itself to-day."
+
+The words of Agardh, written in 1824, are almost as true to-day. The lack
+of authentic specimens, which we hope will be remedied in time by the
+collections of the Smithsonian Institute, numerous incorrectly labelled
+slides in amateur collections, the imperfections of figures copied and
+recopied, without regard to relative size or correct references, and the
+confusion in the attempts to harmonize different descriptions, deter the
+student at the outset. The remaining difficulties mentioned by Agardh add,
+however, to the remarkable interest these forms have always had, since no
+increase in optical perfection of the microscope serves to lessen the
+mystery of their structure and mode of growth.
+
+
+CLASSIFICATION
+
+The few species of diatoms first discovered were included by Lyngbye,
+Dillwyn, and others in the genus _Conferva_. In 1824, the species,
+increased to forty-eight, were separated by Agardh into eight genera
+distinguished partly by their mode of growth. But little change was made
+until Heiberg, in 1863, advocated the division into symmetrical and
+asymmetrical forms. Without entering upon a general review of the later
+classifications, including Pfitzer's and Petit's divisions according to the
+number and location of the chromatophores, or the arrangement of Prof. H.
+L. Smith, because of the presence or absence of a raphe, or that of
+Mereschkowsky into motile and immotile forms, the modification of all of
+these methods by Schuett is here adopted, varied in accordance with certain
+monographs which appear to offer advantage.
+
+It is customary, especially among writers who are familiar with other
+classes of plants, to decry any classification of diatoms according to the
+markings of their siliceous envelopes. As, however, one of the chief
+distinctions of the class is the possession of a more or less siliceous and
+indestructible frustule, and as the cell and its contents are never seen
+except within the valves, their variety forms the only available method of
+identification. The cell contents, owing to the difficulty of observing
+their living condition, their continued change, their lack of distinct
+variation and their entire absence in fossil forms, render their
+consideration as a complete method of classification an impossibility. If,
+however, the cell contents can be brought into relation with the markings
+of their siliceous envelope, it will be a consummation for which the future
+student of these complicated forms ought to be grateful. That this result
+is one to be expected may be inferred from the fact that the arrangement of
+protoplasmic masses in the interior of the cell is coincident in some cases
+with markings on the valve, and the character of the endochrome is assuming
+a certain value in accentuating the difference between such forms as
+_Pleurosigma_ and _Gyrosigma_, or in the resemblance between _Hantzschia_
+and _Nitzschia_, or between _Surirella_ and _Campylodiscus_. Mereschkowsky,
+however, states that it is necessary to be careful in "establishing the
+relationship between diatoms based on the resemblance of their
+chromatophores," {8}and further observes that in _Hantzschia amphioxys_,
+_Scoliotropis latestriata_ and _Achnanthes brevipes_, three widely
+separated forms, the chromatophores are essentially the same.
+
+In one of the earliest classifications of diatoms, the individual cell
+received less consideration than the nature of the filament or thallus in
+which many species occur in the first stages of their growth. Those,
+however, which exist in colonies at first are, sooner or later, broken up
+into separate frustules, either before or at the time of their maturity or
+previous to conjugation, while very many species are never seen except in a
+free state. The union of frustules, therefore, is of secondary importance
+and the group must be considered as filamentous or unicellular algae. Their
+relation to other algae is not well determined. Among the _Desmidiaceae_, a
+family of the order _Conjugales_, of the class _Chlorophyceae_, the cells
+are in many forms divided by a constriction into symmetrical halves. The
+Conjugales are starch forming, with walls of cellulose. In the Diatomaceae
+the starch is replaced by oil globules, while the walls of cellulose are
+more or less filled with a deposit of silica. The Conjugales, however,
+reproduce by zygospores and usually contain pyrenoids, as may be seen in
+the parietal chromatophores of _Spirogyra_. In the class _Heterokontae_ we
+have the reserve material in the form of oil, instead of starch, but there
+are no pyrenoids. To this class belongs the order _Confervaceae_, in which
+the cells are unicellular or filamentous, and to which all of the
+Diatomaceae were referred. While, therefore, Diatomaceae have a close
+affinity to the Desmidiaceae and to the Confervaceae, the determination of
+their origin, one from another, or from a common ancestral type, appears to
+be a matter of conjecture.
+
+
+
+
+{9}MORPHOLOGY AND DEVELOPMENT
+
+
+THE CELL
+
+The cell membrane is composed of two usually equal parts, each of which
+consists of a valve and a girdle or zone formed of cellulose modified by
+silica deposited in an insoluble state from a very dilute aqueous solution.
+The valves are more siliceous and robust than the girdle. Both are in most
+species easily separable, or at least the bands of the girdle which may be
+more or less closely fastened to the valves have a motion over each other
+permitting the cell to enlarge at pleasure. The longitudinal diameter of
+the cell, or the distance between the centres of the two valves, will vary
+according to the convexity of the valve and the age of the frustule which
+may be often determined by the width or number of the girdle bands. These,
+owing to their diversity of form and arrangement, will be further described
+under the generic diagnoses.
+
+The siliceous cell-wall is covered on the outside by a layer of protoplasm
+called the coleoderm. This layer may be quite thin and evident only when
+treated with fuchsin or Bismarck brown, or it may be of considerable
+thickness. The cell contains the cytoplasma, protoplasm, cell-sap,
+endochrome, pyrenoids, oil globules and nucleus, together with certain
+other less understood bodies.
+
+The Cytoplasma is a thin skin of colorless plasma covering the entire inner
+surface of the cell. It is invisible in the living cell but is evident in
+plasmolysis. In long forms it is thickened at the ends and is condensed at
+the plasma bridge which frequently connects the two valves and divides the
+cell into two parts, each containing more or less protoplasm surrounding
+the vacuole in which are found the cell-sap and certain granules. In some
+forms, as Meloseira, the cytoplasma includes the entire mass of protoplasm.
+
+The Endochrome is seen in the form of one or more bands or plates, of a
+yellowish or brownish color, on the inner side of the valves or connective
+zone, or in granules or irregular masses, more or less numerous, on the
+inner walls, or sometimes grouped near the centre. It consists of a mixture
+of chlorophyll and diatomine which differ in their relative solubility in
+alcohol and in their spectroscopic analyses. The color varies from green to
+a chocolate brown in proportion to the amount of diatomine. So far as the
+function of the endochrome is concerned it does not appear to differ from
+that of ordinary chlorophyll, absorbing, under the influence of light, the
+carbon, and disengaging the oxygen of the carbonic anhydride in the water.
+Diatoms do not live in absolutely pure or non-aerated water. The individual
+plates or granules of the endochrome are called chromatophores. Their
+number and significance will be referred to in the description of genera.
+
+THE PYRENOIDS.--In the chromatophores of many species are found colorless,
+homogeneous bodies, strongly refractive, of various shapes, usually
+lenticular or fusiform, which are known as Pyrenoids (Schmitz). They are
+scarcely evident in the living cell, but are distinguished by the action of
+haematoxylin and other reagents. Flat forms occur in Surirella and
+Pleurosigma, lens forms in Pinnularia, Stauroneis, Synedra, Fragilaria and
+Nitzschia, while a spherical form is found in Cymbella cuspidata. The
+pyrenoids are always imbedded in the chromatophore. Their growth is by
+division. Schmitz considers them a part of the living chromatophore, and
+their substance as working material which in excess has become resolved
+into the nature of a crystal which its form sometimes resembles.
+Comparisons are made between them and crystalloids found in certain
+monocotyledons. The pyrenoid is evidently concerned in the formation of the
+chromatophore, or in its division. Much of the conjecture, however, is due
+to the behavior of pyrenoids in other plants.
+
+{10}OIL GLOBULES.--It has been established by Pfitzer that starch and
+sugar, as assimilation products, are replaced by oil in the cells of
+diatoms ("da bekannlich Staerke und Zucker bei den Bacillariaceen nicht
+nachzuweisen sind"). The oil drops are more or less numerous, of various
+sizes, and are found in the cytoplasma, the cell-sap, and sometimes the
+chromatophores. Mereschkowsky describes certain globules as elaeoplasts,
+which he divides into four kinds according to their number and position.
+Whether all of these are oil globules is a question not yet determined.
+
+Other bodies, known as "Buetschli granules," or volutin, and described as
+"little blisters filled with a tolerably robust refractive substance," are
+considered by Lauterborn to be a nitrogen reserve store. They are found in
+the cytoplasma, or in the cell-sap, and can be fixed in picric acid and
+stained in methylene blue.
+
+NOTE.--For a discussion of the morphology of diatoms and a valuable resume
+of the investigations of Buetschli, Karsten, Lauterborn, Mereschkowsky,
+Mueller, Pfitzer, Schuett, and others, the student is referred to "Der Bau
+der Diatomzelle," by Dr. Otto Heinzerling, in "Bibliotheca Botanica," 1908.
+
+
+CELL DIVISION
+
+The growth of diatoms follows the usual method of cell division as
+described by Sachs (Text Book of Botany, 2nd ed., p. 16): "The nucleus of a
+cell which is about to divide becomes broader, assuming the form of a
+biconcave lens, and its nucleolus breaks up into irregular granules which
+together with its other granular contents begin to form a nuclear disc in
+the equatorial plane. A delicate striation is now apparent in what is
+becoming the long axis of the nucleus, at right angles to the nuclear disc,
+and the characteristic nuclear spindle is gradually produced. The nuclear
+disc splits into two halves lying side by side, each of which travels to
+the corresponding pole of the nucleus; thus two nuclei are constituted
+which are connected by fibrillae."
+
+The cell-wall and the chromatophore bands divide, each nucleus passes to
+the centre, and two new cells are formed. In the meantime, to permit of
+this division, the two siliceous valves separate, the girdle bands slipping
+over each other, and opposite the larger or enclosing valve a new valve is
+formed, the girdle band of which is seen later within the girdle of the
+mother valve. Opposite the smaller valve of the original cell and adjoining
+the new valve, another valve is formed which also produces a girdle within
+the girdle of the smaller valve. As a result of division we have,
+therefore, the valves of the original, or mother cell, the two new valves
+and four girdle bands. (Pl. 40, Figs. 18 and 19.)
+
+In the process of division, the continual formation of new valves, enclosed
+in the older girdle bands, will naturally cause a reduction in the size of
+the frustule. While this reduction, owing to the elasticity of the girdle,
+does not always occur, I believe, yet, in most cases, the diameter is so
+reduced that a rejuvenescence of growth is required. This is caused by the
+production of auxospores which may appear without conjugation. In this
+process, the beginning of which, in certain species, may be noticed by the
+increase in the size of the girdle as in reduplication, the two valves
+separate and within is formed a more or less spherical mass about twice the
+size of the original frustule and which forms on its circumference two
+large and often shapeless valves. These valves form others which assume the
+appearance of the original valves, but larger, and proceed to grow in the
+usual way. The reduction in size of the frustule seldom proceeds further
+than about half the size of the type form, so that, as a general rule, it
+may be stated that diatoms are not often smaller than half the larger size.
+
+
+REPRODUCTION
+
+The process of reproduction has been observed in many cases, but the
+conclusions reached are somewhat at variance with each other. The auxospore
+formation is simply a {11}method of rejuvenescence. When, however, the
+auxospores are thrown off from filamentous diatoms, it is probable that two
+may conjugate, their contents dividing each into two daughter cells which
+unite into two zygospores. The usual method is the union of two frustules,
+which, throwing off the old valves, coalesce into a single mass of
+protoplasm which produces an auxospore, sometimes called a sporangial
+frustule. It is stated that in some cases two frustules coalesce and
+produce two auxospores.
+
+The existence of spores in diatoms is a much-disputed point. While they
+have never been seen, the inference that they exist is very great, as
+otherwise it becomes difficult to understand the sudden growth of species
+in localities and under conditions that seem to preclude the actual
+presence of the living frustule. It is a matter of common observation that,
+in examining collections of living forms, minute frustules or brownish
+globules appear to resemble larger diatoms. In gatherings of Gomphonema,
+when many specimens are sessile on the same object, numerous intermediate
+sizes, varying from minute globules to the type, are seen, yet not
+positively demonstrable as the same.
+
+Conjugation, the formation of auxospores, and the actual process of cell
+division are seldom seen, as they occur during the night or at least in
+darkness. It is advisable in order to observe reduplication to obtain the
+material about midnight and place it in very dilute alcohol. In filamentous
+forms, however, the cell division is easily observed at any time in its
+various stages. By immersing in picric acid (saturated solution),
+transferring to very dilute alcohol which is gradually increased in
+strength, and then passing through oil of cloves and finally to the
+mounting medium, excellent preparations can be made. By staining with gold
+chloride alone the nucleus is made apparent without further treatment.
+
+
+EVOLUTION OF FORMS
+
+It may be assumed that diatoms originated in the sea; to deny this requires
+evidence of the existence of fresh-water species previous to the Miocene
+period which is entirely marine. In those subject to fluctuations of the
+waves, as pelagic diatoms, their existence appears to be contingent upon
+the methods by which the separate frustules can cohere. Various devices,
+including hooks, spiral bundles, horns and processes exuding threads of
+plasma, exist for holding together the frustules. When marine forms are
+found in quiet waters some of these devices, being no longer of any value,
+cease to grow, although free swimming diatoms are rare. They either occur
+in long chains or are stipitate or sessile. If it is further assumed that
+the fresh-water diatoms are found in greater abundance in later periods,
+the action of running streams makes necessary the provision of some means
+by which the species may continue to colonize. This may be recognized in
+the occurrence of linear forms chiefly in streams. Circular forms, such as
+Cyclotella which have no raphe, are found in quiet waters, such as pools or
+ditches, and never exist living in running streams. Those forms only would
+be able to live in water having a more or less swift current under one of
+three conditions: they must, as in Gomphonema, be adherent to surrounding
+objects by a stipe; or be enclosed in a gelatinous tube, as in
+Homoeocladia; or have an independent motion powerful enough to overcome the
+influence of the current. It is true that many forms with a raphe have no
+apparent motion. In the case of Mastogloia provision is made in a
+gelatinous cushion in which the frustules are preserved. In Cocconeis, with
+a true raphe in one valve only, in Epithemia, with a partial raphe, or in
+certain Eunotiae with a trace of one, we find species evidently degenerate
+and parasitic. The long Synedrae, having only a median line, live in
+running streams, since they are attached at one end to other algae. Forms
+with a true raphe appear to be more highly developed, since they are able
+to seek locations favorable to growth. Given, therefore, the structure of
+the valve, the habitat may be inferred.
+
+
+{12}THE MOTION OF DIATOMS
+
+The erratic backward and forward movement of certain diatoms, especially
+those of the Naviculoid group, or the slow, rolling motion of Surirella,
+has been discussed in so many ways without definite conclusions that a
+brief statement will be sufficient. Osmosis, the amoeboid movement of the
+coleoderm, the protrusion of protoplasm or protoplasmic threads through the
+raphe, the existence of actual organs of locomotion or cilia, and the lack
+of synchronism in the chemical action occurring at the ends of the cell
+which is sometimes divided by the plasma bridge, have been offered in
+explanation. The chief objection to the theory of cyclosis appears to be
+that the resultant motion is so greatly in excess of the rotation of
+protoplasm in the cell. More or less motion is observed in various kinds of
+free cells, but the movement of diatoms is not evident in those without
+either a raphe or a keel upon which and apparently by which the phenomena
+are produced.
+
+Mr. T. Chalkley Palmer, in various articles in the Proceedings of the
+Delaware County Institute of Science, especially in Vols. 1 and 3, gives
+the results of exhaustive experiments. "Nothing, it would seem," he says,
+"could be more conclusive as to the essential sameness of the nature of
+motion in monads and diatoms, than the fact that both monads and diatoms
+require oxygen in order to perform motion, that they come to rest when
+oxygen becomes scarce, and that they resume their motion when oxygen is
+again supplied."
+
+He also thinks "that the living substance of the cell, more or less deeply
+overlaid with coleoderm substance of varying consistency, and itself
+assuming that degree of fluidity which best meets the requirements of the
+situation, permeates the raphes, circulates in the keels, or in some cases
+protrudes quite beyond the silica, and functions as the actual propulsive
+agent."
+
+
+THE FUNCTION OF DIATOMS
+
+Of all forms of vegetation, the Diatomaceae are, perhaps, the most
+ubiquitous. Where-ever a sufficient amount of moisture, heat and light are
+found, they grow. It was during the Miocene period that they first
+appeared, and, as marine forms, reached their greatest development, both as
+to size and beauty of marking, while their prevalence throughout the world
+in enormous quantities has been often mentioned. The Miocene beds of
+Richmond and Maryland continued over the Cretaceous formations of New
+Jersey have outcropped in certain localities within our district, but are
+not considered in this discussion.
+
+The function of diatoms is not essentially different from that of other
+algae in providing food for aquatic animals, such as Salpae and oysters,
+but it is, however, in other respects that they are not only important but
+necessary factors in the preservation of life.
+
+ "Full nature swarms with life; one wondrous mass
+  Of animals, or atoms organized,
+  Waiting the vital breath, when parent heaven
+  Shall bid his spirit blow. The hoary fen,
+  In putrid streams, emits the living cloud
+  Of pestilence. Thro' subterranean cells
+  Where searching sunbeams scarce can find a way,
+  Earth animated heaves."
+
+I am not certain if Thomson fully understood the matter, but he has
+remarkably described the facts. When "the vital breath" of returning spring
+animates the earth, the "subterranean cells" of diatoms, the "atoms
+organized," through the liberation of vast quantities of oxygen,
+immediately begin the purification of the "putrid streams." Were these
+streams not so purified, the accumulation of animal and vegetable debris
+would eventually cause an enormous bacterial growth fatal to animal life.
+
+
+
+
+{13}DIATOMACEAE
+
+
+Unicellular or filamentous. Cells either free, sessile, united in
+filaments, immersed in a gelatinous envelope or in fronds composed of
+branching tubes; microscopic, enclosed in a more or less siliceous envelope
+(frustule), composed of two parts (valves), usually connected by an
+intervening band (zone or girdle). Cell contents include yellowish or
+brownish chlorophyll-like bodies which occur in one or several bands
+(placcochromatic), or as variously distributed granular masses
+(coccochromatic) lining the inner walls. Growth by ordinary cell division
+or by auxospores; sexual multiplication by the formation of sporangia.
+Valves of two kinds: (_a_) Those in which the markings or parts are more or
+less concentric (Centricae); (_b_) Those (Pennatae) in which the parts are
+more or less symmetrically divided by a line (pseudoraphe) or by a cleft
+(raphe).
+
+
+
+CENTRICAE
+
+Valves without a dividing line or cleft; markings more or less radiate;
+transverse section of frustule circular, polygonal, or elliptical,
+sometimes irregular.
+
+Divided into four groups:
+
+1. _Discoideae._--Frustules (cells) discoid; valves without horns or
+elevations (sometimes with processes).
+
+2. _Solenoideae._--Frustules with numerous girdle bands.
+
+3. _Biddulphioideae._--Frustules box-like, _i. e._, with the longitudinal
+axis greater than in the Discoideae. Valves with two or more angles,
+elevations or horns.
+
+4. _Rutilarioideae._--Valves as if naviculoid, but with irregular or radial
+structure.
+
+Groups 2 and 4 are not included in our description. No. 2 contains plankton
+genera only, while No. 4 consists of genera not yet found in this locality.
+
+
+
+DISCOIDEAE
+
+1. _Coscinodisceae._--Valve not divided by rays or costae into sectors;
+puncta sometimes radiate; ocelli or processes absent.
+
+2. _Actinodisceae._--Valve with radial striae divided into sectors: ocelli
+and processes absent.
+
+3. _Eupodisceae._--Valve disc-shaped with mammiform processes or one or
+more ocelli.
+
+
+
+1. COSCINODISCEAE
+
+(_a_) _Meloseirinae._--Frustules short, in chains.
+
+(_b_) _Coscinodiscinae._--Frustules disc form, usually single, rarely in
+short chains.
+
+
+
+(_a_) MELOSEIRINAE
+
+1. _Meloseira._--Valve punctate, with a constriction or furrow between edge
+of valve and girdle.
+
+2. _Gaillonella._--Valve punctate, with a circular collar or crest near
+edge of valve.
+
+3. _Lysigonium._--Valve punctate, neither keeled nor constricted.
+
+4. _Hyalodiscus._--Valve punctate in the centre; border with decussating
+radial lines.
+
+5. _Stephanopyxis._--Border of valve with a crown of thorns; valve
+areolate.
+
+6. _Pyxidicula._--Valve areolate, with a border of spines.
+
+
+{14}MELOSEIRA AG. (1824), em. DE TONI (1892)
+
+(melos, a limb or member, and seira, a chain)
+
+Frustules globose, ellipsoidal or cylindrical, concatenate, closely joined
+together. Valve either simply punctate or punctate and areolate. A
+constriction of the cell-wall, forming a furrow between the edge of the
+valve and the girdle, is more or less evident.
+
+The genus Meloseira constituted by Agardh has been variously modified by
+Kuetzing, Thwaites, Wm. Smith, Van Heurck, De Toni, and others. In Systema
+Algarum Agardh included certain species of Conferva, of Lyngbye, Dillwyn
+and others, and limited his genus to frustules more or less globose (fila
+articulata ad genicula constricta), although in his Conspectus Criticus (p.
+64), he modifies the description (fila teretia articulata, articulis
+diametro aequalibus vel longioribus) to include M. varians. As, however,
+Lysigonium Link, Gaillonella Bory, and other genera enlarged by Ehrenberg
+and Kuetzing, came to be included under Meloseira, Thwaites suggested the
+division of the genus into two: Orthosira, in which the frustules are not
+convex at the ends and Aulacosira in which no central line is apparent but
+with two distinct sulci. Wm. Smith adopts the genus Orthosira but rejects
+Aulacosira, including all forms under the former genus and Meloseira,
+suggesting that differences "exist in the formation of the sporangia" of
+the two genera. M. varians and M. crenulata appear to form auxospores or
+sporangial frustules in different ways, as will be noticed hereafter.
+
+As, however, the present state of our knowledge is so limited and as much
+confusion would result in further changing the nomenclature, I shall adopt,
+for the most part, the division made by De Toni, separating Gaillonella and
+Lysigonium and employing the name Meloseira as emendated in Sylloge
+Algarum, although, as stated, it omits the species of Agardh. That a
+further division may be necessary is indicated by the differences existing
+between the Orthosira forms and the others.
+
+
+ANALYSIS OF SPECIES
+
+
+  Frustules cylindrical and lengthened:
+
+    Valves with two distinct furrows; granules small          distans
+
+    Valves with coarse granules                               granulata
+
+    Valves denticulate on the margin                          crenulata
+
+    Valves denticulate and constricted                        roeseana
+
+    Valves with row of large puncta on the girdle side        undulata
+
+  Frustules cylindrical and compressed:
+
+    Valves punctate and areolate                              sulcata
+
+The chromatophores consist of circular and compressed or irregular flat
+granules which lie along the wall of the cell.
+
+
+MELOSEIRA DISTANS (EHR.) KUETZ.
+
+Frustules cylindrical, slender, with two furrows, one on each side of the
+suture; valve in zone view with fine puncta in longitudinal rows; puncta in
+valve view scattered. L. 7-10 [mu].
+
+_Meloseira nivalis_ Wm. Sm.
+
+_Coscinodiscus minor_ Wm. Sm.
+
+Fresh water. Fossil in New England deposits.
+
+Pl. 1, Figs. 8 and 9.
+
+NOTE.--In all species of Meloseira, as well as Gaillonella and Lysigonium,
+the frustules are so closely coherent that when the filaments are broken
+entire frustules are less frequently found than a union of two valves of
+contiguous frustules.
+
+
+{15}MELOSEIRA GRANULATA (EHR.) RALFS
+
+Frustules cylindrical, robust, 5-18 [mu] in diam., with large granules in
+longitudinal, sometimes spiral, lines, variable in size and arrangement in
+the same filament. Valve in valve view with scattered puncta. Variable in
+relative width and length, passing to M. crenulata.
+
+_Gaillonella granulata_ Ehr.
+
+_Orthosira punctata_ Wm. Sm.
+
+Fresh water. Fossil at Coldspring, L. I.
+
+Pl. 1, Fig. 10.
+
+
+MELOSEIRA CRENULATA (EHR.) KUETZ.
+
+Frustules cylindrical, with furrows on each side of the suture, 10-20 [mu]
+in diam.; puncta in longitudinal rows. Margins of valves denticulate at the
+junction of the frustules; valves with puncta scattered at the centre,
+radiate at the circumference.
+
+Common in fresh water; quite variable in size.
+
+_Gaillonella crenulata_ Ehr.
+
+_Orthosira orichalcea_ Wm. Sm. in part; not Conferva orichalcea. Mertens or
+Gaillonella aurichalcea Ehr. and Bailey.
+
+Pl. 1, Figs. 1 and 2.
+
+
+MELOSEIRA ROESEANA RAB.
+
+Frustules cylindrical, constricted toward each end, with coarse,
+longitudinal striae; valve convex, striae punctate, radiating, with several
+large granules at the centre. Connective zone with longitudinal rows of
+fine puncta. Diam. 12-45 [mu].
+
+_Orthosira spinosa_ Grev.
+
+Fresh water. Media, Pa. (Palmer); not common.
+
+Pl. 1, Figs. 5 and 6.
+
+
+MELOSEIRA ROESEANA VAR. EPIDENDRON (EHR.) GRUN.
+
+Frustules denticulate at the margin; valve with coarse granules at the
+centre from which radiate lines of fine puncta.
+
+Wet rocks of the Wissahickon.
+
+Pl. 1, Figs. 3 and 4.
+
+
+MELOSEIRA UNDULATA (EHR.) KUETZ.
+
+Frustules single or in twos, usually broader than long, constricted near
+the margin. Valve with six to twelve internal projections forming with the
+outline of the constriction of the valve a polygonal figure within the
+circumference. Surface of the valve with radiating lines of puncta
+disappearing toward the centre, at which are numerous coarse puncta.
+
+_Meloseira gowenii_ A. Schmidt.
+
+Blue clay of Philadelphia, especially common at Twelfth and Market Sts.
+
+Pl. 1, Figs. 15, 16, 17.
+
+
+MELOSEIRA SULCATA KUETZ.
+
+Frustules quite robust, with diam. several times the length, deeply
+furrowed at the margin, areolate and punctate. Valve with radiating striae
+disappearing toward the centre, and with a double row of cells near the
+margin, the outer one having the appearance of a crown of teeth.
+
+_Gaillonella sulcata_ Ehr.
+
+_Paralia sulcata_ (Ehr.) Cleve.
+
+_Paralia marina_ Heib.
+
+{16}Marine and brackish. Common in all parts of the world, and fossil in
+the Miocene. The Philadelphia form is the var. genuina Grun.
+
+Pl. 1, Figs. 11 and 12.
+
+In a gathering from Media of Meloseira crenulata (Palmer leg.), occasional
+filaments are noticed with much longer and narrower frustules which become
+enlarged in the middle and are seen to contain inner frustules in the
+process of still further division, as shown in Fig. 2, Pl. 38.
+
+Meloseira dickei Thwaites shows internal box-like cells placed one within
+the other, which were supposed by Thwaites to be a method of reproduction.
+Wm. Smith doubts this, but is unable to offer any explanation. In the
+present form the mode of reduplication is that usually found in filamentous
+forms, but in this case the presence of perfect frustules enclosing others
+in the process of still further division has been heretofore unfamiliar to
+me. The swelling in the middle appears to indicate that not all filamentous
+diatoms are reduced in size by subdivision. In outline the valve is like
+that of a "truncated cone," as described by Petit in referring to
+Gaillonella granulata var. bambusina Petit (Diat. Nouv. et Rares, Jour. de
+Micrographie, 1890).
+
+
+GAILLONELLA BORY DE ST. VINCENT (1823)
+
+(named after Gaillon, a botanist of Dieppe)
+
+Frustules ellipsoidal, united in long filaments, usually found in pairs;
+each valve is furnished with a circular collar or crest extending at right
+angles to the convex edge. Valve hyaline at the centre from near which
+radiate lines of fine puncta, 18-20 in 10 [mu].
+
+NOTE.--The original names of both Meloseira and Gaillonella are retained,
+as there is no good reason for contracting the Greek diphthong in the
+first, and the second is the correct spelling.
+
+
+GAILLONELLA NUMMULOIDES (DILLW.) BORY
+
+Frustules as in the generic diagnosis. Diam. 30 [mu].
+
+_Conferva nummuloides_ Dillwyn (Brit. Confervae, p. 45, Sup. Pl. B).
+
+_Meloseira nummuloides_ Ag.
+
+Heiberg and O'Meara assign this species to _Lysigonium moniliforme_
+(Muell.) Link, which is not keeled. While Dillwyn's and Lyngbye's figures
+do not show the keel, it is probable from their descriptions that the
+angular outline produced by the keel was noticed.
+
+Marine or brackish. Coast of New Jersey; Hudson River (Bail.).
+
+Pl. 1, Figs. 13 and 14.
+
+_Gaillonella moniliformis_ of Bailey is this form, as he describes it as
+having "two minute projections of the delicate transverse ridges seen near
+the ends of the two globules belonging to a joint." (Amer. Jour. Science,
+1842, p. 89, Pl. 2, Fig. 3.)
+
+
+LYSIGONIUM LINK (1820)
+
+(luo, to loose, and gonu, a joint)
+
+Frustules globose, concatenate; valve simply punctate.
+
+
+LYSIGONIUM MONILIFORME (MUELL.) LINK
+
+Frustules usually in twos, not keeled; valve with puncta in longitudinal
+lines, the puncta of the enveloping zone larger and in transverse rows. L.
+25-40 [mu] (De Toni).
+
+_Conferva moniliformis_ Mueller (1783).
+
+{17}_Conferva nummuloides_ Eng. Bot. pl., 2287, not Dillwyn.
+
+_Meloseira borreri_ Grev.
+
+_Lysigonium nummuloides_ (Lyngb., Kuetz.) O'Meara = _Gaillonella
+nummuloides_ (Dillw.) Bory. See O'Meara, p. 248.
+
+Marine and brackish. Long Island Sound and coast of New Jersey.
+
+Pl. 1, Fig. 7.
+
+
+LYSIGONIUM VARIANS (AG.) DE TONI
+
+Frustules cylindrical, in long filaments, slightly constricted on each side
+of the suture; puncta in oblique rows in zone view. Valves 15-35 [mu] in
+diam. (De Toni), sub-plane, with fine puncta in lines radiating from the
+centre. Under medium magnification the frustules appear smooth. Very
+variable in size.
+
+_Meloseira varians_ Ag.
+
+Fresh water. Common in ditches and springs.
+
+Pl. 1, Figs. 18 and 19.
+
+
+HYALODISCUS EHR. (1845)
+
+(hyalos, transparent, and discus, a disc)
+
+Frustules spheroidal; valve with a flattened, irregularly punctate
+umbilicus from which proceed radiating or decussating lines of fine puncta.
+
+
+ANALYSIS OF SPECIES
+
+
+  Valves divided into sectors                                 stelliger
+
+  Valves not divided but interrupted by short dark lines at
+    intervals                                                 radiatus
+
+  Valves with very fine puncta                                scoticus
+
+
+HYALODISCUS STELLIGER BAIL.
+
+Valve with puncta in oblique decussating rows which, by reason of the
+difference in obliquity, form numerous sectors. Umbilicus irregular, with
+scattered, coarse puncta. Margin wide, striated.
+
+_Podosira maculata_ Wm. Sm.
+
+Blue clay. Not common.
+
+Pl. 1, Fig. 22.
+
+
+HYALODISCUS RADIATUS VAR. ARCTICA GRUN.
+
+Valve with radiating puncta from a rather small umbilicus, the rays
+interspersed with short, dark lines, having the appearance of spines, at
+irregular intervals. Margin broad, striated.
+
+_Pyxidicula radiata_ O'Meara.
+
+The Philadelphia form corresponds exactly to Grunow's variety which has
+closer puncta than the type form.
+
+Blue clay. Rather rare.
+
+Pl. 1, Fig. 21.
+
+
+{18}HYALODISCUS SCOTICUS (KUETZ.) GRUN.
+
+Valve small, with puncta about 24 in 10 [mu], appearing hyaline.
+
+De Toni remarks that it resembles a small form of H. subtilis which occurs
+north and south of our limits and is yet likely to be recorded.
+
+_Cyclotella scotica_ Kuetz.
+
+_Podosira hormoides_ Wm. Sm.
+
+Blue clay. Not rare.
+
+Pl. 1, Fig. 20.
+
+Endochrome in the form of four flaps or patches bound together about a
+common pyrenoid. In H. subtilis numerous rod-shaped chromatophores lie in a
+row and are not bound in the centre (Mereschkowsky).
+
+
+STEPHANOPYXIS EHR. (1844) em. GRUN. (1884)
+
+(stephanos, a crown, and pyxis, a kind of vase or box)
+
+Frustules ellipsoidal, concatenate; valves tumid, of unequal convexity,
+coarsely areolate, the cells in rows parallel to the longitudinal axis, not
+radiate, with stray spines or teeth placed concentrically more or less near
+the margin.
+
+According to Karsten the chromatophores are round or angular discs which
+lie near the connective zone.
+
+
+STEPHANOPYXIS TURRIS (GREV.) RALFS
+
+Valve cylindrical, with a crown of stout spines less than the diameter of
+the valve near the margin. Cells hexagonal, about 2 in 10 [mu], sometimes
+punctate. The valve having the greater convexity has the larger spines,
+though usually less of them.
+
+_Creswellia turris_ Grev. (Gregory, Diat. of the Clyde, T. R. S. E., vol.
+21, part 4, p. 66.)
+
+_Stephanopyxis appendiculata_ Ehr.?
+
+Creswellia is incorrectly based, as stated by Ralfs, on the concatenation
+of the valves which was not noticed by Ehrenberg in the fossil forms. It
+had been suggested by Kuetzing in Systema Algarum (p. 126).
+
+Blue clay. Port Penn and Smith's Island.
+
+Pl. 2, Figs. 1 and 2.
+
+
+STEPHANOPYXIS CORONA (EHR.) GRUN.
+
+Valve larger than in turris, sub-globose, coarsely areolate cells, 4-5 in
+10 [mu]. One valve furnished with a crown of teeth shaped like the letter T
+and united at the top into a ring above the margin of the valve; the other
+valve with long spines more or less concentrically arranged.
+
+Blue clay. Not common. Fossil in the Nottingham deposit.
+
+Pl. 2, Fig. 3.
+
+NOTE.--The diatomaceous deposit, so often called "Bermuda" or "Bermuda
+tripoli," especially by foreign writers, is in reality the Miocene stratum
+extending for miles along the Patuxent River near the village of
+Nottingham, Md. The author is perfectly familiar with the location, having
+made large collections there. The mistake in the name is due to the fact
+that Prof. Bailey received material from Mr. Tuomey marked "Bermuda
+Hundred," which is located near Petersburg, Va. Attempts have been made to
+find material there and while there is an earth containing Miocene diatoms
+at Petersburg, it does not exactly correspond to the material sent to
+Ehrenberg by Bailey, who was in doubt as to the locality. The Bermuda
+Islands are of coral formation and have no deposits of diatomaceous earth.
+
+
+{19}PYXIDICULA EHR. (1833)
+
+(dim. of pyxis, a box)
+
+Frustules globular, solitary or in short fasciae. Valve more or less
+hemispherical, areolate, destitute of spines.
+
+
+PYXIDICULA CRUCIATA EHR.
+
+Valve hemispherical, with large, hexagonal cells. An inner stratum is
+finely punctate.
+
+Blue clay. Walnut St. Bridge. Rare.
+
+Pl. 38, Fig. 8.
+
+This form is not usually described as having punctate areolae, but it does
+not apparently differ from other forms of Pyxidicula of Ehrenberg as
+described by Kuetzing (Species Algarum, pp. 21-23), including _P.
+areolata_. In fact, it differs from Stephanopyxis, which is also sometimes
+punctate, only in the absence of spines. In fossil deposits the absence of
+an easily detached stratum is not significant. The difference, except in
+size, between it and _P. mediterranea_ Grun. (V. H. S., Pl. 95, Figs. 15
+and 16), I am unable to determine.
+
+Although many species of Meloseira are fresh-water, the habitat of the
+group Meloseirinae is, in general, marine. It more nearly coincides in
+structure and development with other algae not diatomaceous, the siliceous
+envelope constituting its most distinctive feature. As we proceed in the
+classification, the structure both of the frustule and contents becomes
+more complicated.
+
+
+
+(_b_) COSCINODISCINAE
+
+1. _Cyclotella._--Valve with two concentric divisions of different
+structure, one a wide border and the other a central surface.
+
+2. _Coscinodiscus._--Valve areolate or punctate, with a narrow border of
+the same structure.
+
+
+CYCLOTELLA KUETZ. (1833)
+
+(cyclos, a circle)
+
+Frustules single or geminate, cylindrical, short, in zone view rectangular
+or with undulating sides. Valve usually with smooth or punctate striae,
+centre sometimes bullose, smooth, or with granules scattered or radiating.
+
+Chromatophores numerous along the valves (Pfitzer).
+
+
+CYCLOTELLA STRIATA (KUETZ.) GRUN.
+
+Valve 30-80 [mu] in diam., with coarse striae, 7-12 in 10 [mu], centre
+coarsely punctate and bullose.
+
+_Coscinodiscus striatus_ Kuetz.
+
+_Cyclotella dallasiana_ Wm. Sm.
+
+Common in the blue clay.
+
+Pl. 2, Fig. 9.
+
+
+CYCLOTELLA MENEGHINIANA KUETZ.
+
+Frustule in zone view rectangular, undulated; valve, 10-20 [mu] in diam.,
+marginal striae robust and transversely punctate, centre radiately
+punctate.
+
+_Cyclotella kuetzingiana_ Wm. Sm. (not Thwaites).
+
+Crum Creek.
+
+Pl. 2, Fig. 8.
+
+
+{20}CYCLOTELLA MENEGHINIANA, VAR. STELLIGERA CL. AND GRUN.
+
+Differs from the type in the coarse radiating lines at the centre.
+
+Broomall Lake, Media.
+
+Pl. 2, Fig. 4.
+
+
+CYCLOTELLA MENEGHINIANA, VAR. STELLULIFERA CL. AND GRUN.
+
+As in type but with the central rays granulate.
+
+Broomall Lake, Media.
+
+Pl. 2, Fig. 12.
+
+
+CYCLOTELLA STYLORUM (BR.?) V. H.
+
+Margin striated, the alternate striae thickened near the border, producing
+an appearance of subquadrate cells. Centre faintly granulate, the outer
+border of which is encircled by 10-12 puncta, each of which is surrounded
+by a small hyaline space.
+
+Blue clay. Rare.
+
+Van Heurck gives this form doubtfully as a variety of _striata_, while De
+Toni makes it synonymous with it. Van Heurck's figure is not that of
+Brightwell, but as the specimen above described is, I believe, exactly the
+same as Van Heurck's, I retain his name.
+
+Pl. 2, Fig. 10.
+
+
+CYCLOTELLA COMTA (EHR.) KUETZ.
+
+Valve with marginal striae well marked, each third or fourth costa more
+robust than the others. Central part finely striated, the striae punctate,
+radiating.
+
+Fresh water.
+
+Pl. 2, Fig. 7.
+
+The form here figured is probably the variety _radiosa_ Grun. and is from a
+New England specimen. It is quite likely to occur in this locality.
+
+
+CYCLOTELLA OPERCULATA (AG.) KUETZ.
+
+Frustules in zone view undulated. Angles rounded. Marginal costae
+alternating with minute spines; centre nearly smooth, depressed, convex or
+flexuose.
+
+Fresh water.
+
+Pl. 2, Figs. 5 and 6.
+
+The figure is drawn from a specimen from Boston, Mass., H. L. Smith Type
+Slide No. 107, marked equivalent to _C. minutula_ Wm. Sm.
+
+
+CYCLOTELLA ANTIQUA WM. SM.
+
+Marginal costae alternating with thick puncta; centre finely granulate with
+subtriangular elevations. Frustules in zone view rectangular.
+
+Blue clay.
+
+Pl. 2, Fig. 11.
+
+The form corresponds to the original specimens of Wm. Smith in the deposit
+of Stavenger, Norway.
+
+The genus Cyclotella comprises about seventy specific names, many of which
+may be referred to other genera, while some of Ehrenberg's are incapable of
+verification on account of the small size of the figures and the lack of
+sufficient description. About half of the forms are marine. The fresh-water
+species are usually found living in more or less stagnant water or in pools
+contaminated with drainage, being an exception to the general rule that
+diatoms are more abundant in water free from deleterious matter.
+
+
+{21}COSCINODISCUS EHR. (1838)
+
+(coscinon, a sieve, and discus)
+
+Frustules solitary, cylindrical, compressed; valve circular or elliptical;
+surface flat or sometimes convex near the border; markings more or less
+angular, radiating, sometimes fasciculate; border usually well defined.
+Central space, if present, hyaline, sometimes surrounded with a rosette of
+large cells.
+
+Chromatophores round, angular or irregular discs usually without pyrenoids
+(Karsten).
+
+Rattray's classification is here followed, so far as it refers to our
+species.
+
+_Excentrici._--Valves circular; central space absent; markings angular, in
+oblique, decussating rows.
+
+_Lineati._--Central space absent; markings angular, oblique decussating
+rows straight.
+
+_Fasciculati._--Markings fasciculate, or sometimes only near the border.
+
+_Radiati._--Markings rounded or angular, more or less radiate.
+
+_Elaborati._--Valves elliptical, markings rounded.
+
+
+EXCENTRICI
+
+COSCINODISCUS EXCENTRICUS EHR.
+
+Valve with a hyaline excentric space from which proceed, usually in six
+directions, rows of polygonal markings decreasing toward the narrow,
+coarsely striated border, the rows appearing convex toward the centre.
+Apiculi at unequal distances apart. Quite variable in size.
+
+Common in the blue clay and along the coast.
+
+Pl. 2, Figs. 14 and 20.
+
+Fig. 20 is probably var. _perpusilla_ Grun. (Diat. Fr. Jos. L., Pl. 4 (D),
+Fig. 7).
+
+
+LINEATI
+
+COSCINODISCUS LINEATUS EHR.
+
+Valve circular, markings hexagonal, cells in parallel rows. Border narrow,
+cellular.
+
+Blue clay and Atlantic coast. Not common.
+
+Pl. 3, Fig. 8.
+
+
+FASCICULATI
+
+COSCINODISCUS NITIDUS GREG.
+
+Valve flat, markings rounded, distant, radiate, decreasing toward the
+border which is coarsely striate. Quite variable in size and in the
+distance between the markings.
+
+Blue clay and Atlantic coast. Common.
+
+Pl. 2, Fig. 18.
+
+
+COSCINODISCUS NITIDULUS GRUN.
+
+Valve usually not quite circular; markings smaller than in nitidus and
+fasciculate near the border.
+
+Blue clay.
+
+Pl. 2, Fig. 19.
+
+Various intermediate forms between nitidus and nitidulus occur.
+
+
+COSCINODISCUS SUBTILIS EHR.
+
+Markings polygonal, irregular at the centre, but forming numerous fasciculi
+radiating {22}toward the border, the rows parallel to the central row of
+each fasciculus. Border narrow with fine striae; apiculi often present
+between the fasciculi.
+
+Blue clay and along the coast. Very common in the water supply of
+Philadelphia and Camden, where the diameter seldom exceeds 40 [mu] and the
+markings on the semi-radius are 10 in 10 [mu].
+
+Pl. 2, Fig. 17.
+
+
+COSCINODISCUS DENARIUS SCHMIDT
+
+Markings larger than in C. subtilis, equal, forming usually ten fasciculi,
+each beginning near the semi-radius and containing ten parallel rows of
+granules.
+
+Common in the blue clay and sparingly along the coast.
+
+Pl. 2, Fig. 13.
+
+Forms are found intermediate between C. subtilis and C. denarius, as shown
+in Fig. 15.
+
+
+COSCINODISCUS POLYACANTHUS GRUN.
+
+Markings angular, 10 in 10 [mu], decreasing toward the border, fasciculate.
+Apiculi large, twelve or more, usually inserted at the middle of each
+fasciculus, and extending into the interior of the cell. The apiculi in
+outline resemble the heads of horse-shoe nails, and are seen with
+difficulty except when the valve is examined from the inner side. Border
+narrow, striated. Diam. 70 [mu].
+
+Pensauken, N. J., artesian well.
+
+Pl. 38, Fig. 5.
+
+Rattray's description of _C. polyacanthus_ var. _intermedia_ Grun., from
+Cape Wankarema, Siberia, gives the diam. as 60 [mu], and there are about 7
+markings by actual count in 10 [mu] in Grunow's figure (Diat. Fr. Jos.
+Land, Pl. 3 (C), Fig. 25). The apiculi are more numerous, but there appears
+to be little doubt of the general similarity. The Philadelphia form is
+abundant in the Pensauken well deposit at a depth of 33 ft. The apiculi
+become quite distinct in slides stained with silver nitrate by Mr. F. J.
+Keeley; they are distinct from small apiculi sometimes evident between the
+fasciculi. The specimens in the Pensauken deposit are mingled with other
+forms which cannot be distinguished from _C. subtilis_. Whether the two are
+identical, I am unable to determine. Rattray (Rev. Cos., p. 47) refers to
+H. L. Smith's Type Slide No. 100, from rice-field mud, Savannah, Ga., as
+_C. subtilis_. In Smith's slide, in my possession, a number of the forms
+show faint outlines of the large apiculi and are otherwise exactly like C.
+polyacanthus.
+
+
+RADIATI
+
+COSCINODISCUS VELATUS EHR.
+
+Markings angular, decreasing slightly toward the coarsely striated border,
+covered with fine puncta.
+
+Blue clay.
+
+Pl. 3, Fig. 2.
+
+
+COSCINODISCUS MARGINATUS EHR.
+
+Markings rounded, large, decreasing toward the broad border, which is
+coarsely marked with distant striae. The cells are punctate.
+
+Common in the blue clay.
+
+Pl. 3, Fig. 9.
+
+In the fossil forms the puncta are not evident, hence the species is
+usually described as not punctate.
+
+
+{23}COSCINODISCUS RADIATUS EHR.
+
+Markings polygonal, slightly decreasing toward the border where they are
+much smaller; border well marked, striate. Quite variable in size.
+
+Common in the blue clay and along the coast.
+
+Pl. 3, Fig. 11. Fig. 1 is probably a smaller form.
+
+
+COSCINODISCUS SUBAULACODISCOIDALIS RATTR.
+
+Markings small, decreasing toward the border in somewhat fasciculate rows.
+About one-third the distance from the border are five (Rattray finds six)
+well-marked apiculi somewhat resembling those of Aulacodiscus. Border
+narrow, hyaline.
+
+Rare in the lower stratum of the blue clay.
+
+Pl. 3, Fig. 4.
+
+
+COSCINODISCUS ARGUS EHR.
+
+Markings angular with central dots, increasing from the centre toward the
+border, where they are smaller.
+
+Blue clay.
+
+Pl. 3, Fig. 7 (a small form).
+
+
+COSCINODISCUS BIANGULATUS SCHMIDT
+
+Central space and rosette absent, markings large, angular, not punctate,
+with large central papillae, decreasing toward the border. Border wide,
+coarsely marked with rows of granules, and with two indentations on the
+inner side distant from each other about two-thirds of the diameter.
+
+Blue clay.
+
+Pl. 3, Fig. 3.
+
+Distinguished from Coscinodiscus asteromphalus var. omphalantha Grun.,
+which also has two constrictions, by the absence of punctate markings.
+
+
+COSCINODISCUS ASTEROMPHALUS EHR.
+
+Central space small, surrounded by a rosette of large polygonal cells from
+which radiate hexagonal cells, increasing about half way toward the border
+and then slightly decreasing. Cells punctate.
+
+Blue clay.
+
+Pl. 2, Fig. 16; Pl. 40, Fig. 12.
+
+
+COSCINODISCUS ASTEROMPHALUS VAR. OMPHALANTHA (EHR.) GRUN.
+
+Central space absent, rosette evident. Markings 2-1/2 in 10 [mu], somewhat
+smaller near the rosette and decreasing near the border, which is
+constricted in two places, as in C. biangulatus.
+
+Blue clay.
+
+Pl. 38, Fig. 10.
+
+
+COSCINODISCUS OCULUS-IRIDIS EHR.
+
+Central space and rosette distinct; markings polygonal, not punctate, with
+large papillae, smaller near the rosette, increasing toward the
+semi-radius, and then decreasing to the striated border which is
+comparatively narrow.
+
+Blue clay and Atlantic coast.
+
+Pl. 3, Fig. 10.
+
+
+{24}ELABORATI
+
+COSCINODISCUS LEWISIANUS GREV.
+
+Valves elliptical, major axis a little more than twice the minor. From a
+point, usually near one side, radiate rows of granules in lines nearly
+parallel to the major axis. Border broad, with distinct striae.
+
+Great Sedge Island, N. J. (artesian well), and in outcrops later than the
+Miocene, where it is usually found.
+
+Pl. 3, Fig. 5.
+
+
+
+2. ACTINODISCEAE
+
+ACTINOPTYCHINAE
+
+Valves divided into sectors alternately elevated and depressed.
+
+(1) _Actinoptychus._--Sectors plane.
+
+(2) _Polymyxus._--Sectors convex.
+
+
+ACTINOPTYCHUS EHR. (1839) em. V. H. (1890)
+
+(actis, a ray, and ptyx, a fold)
+
+Frustule cylindrical, less in length than the diameter, in zone view
+undulated. Valve divided into six or more sectors alternately raised and
+depressed, areolate and punctate, varying in the alternate divisions. The
+areolation is confined to the outer layer of the valve while the punctation
+is usually on an inner valve often found detached. Processes on the border,
+three or more. Umbilicus circular or angular, hyaline.
+
+
+ANALYSIS OF SPECIES
+
+
+  Sectors, six                                                undulatus
+
+  Sectors, eight or more, cellular                            heliopelta
+
+  Sectors, fourteen, punctate                                 vulgaris
+
+
+ACTINOPTYCHUS UNDULATUS (KUETZ.) RALFS
+
+Valve areolate and punctate in quincunx, divided into six equal sectors,
+alternately elevated or depressed, their areolations appearing different.
+Margin well defined. Umbilicus smooth, hexagonal. Processes three,
+sometimes six, inserted within the margin of each alternate division. Very
+variable in size and appearance.
+
+This is the Actinocyclus of Bailey, figured and described in Amer. Jour.
+Science, 1842, p. 93, Pl. 2, Fig. 11, but not named. Kuetzing describes and
+names it and refers to Bailey.
+
+_Actinoptychus omphalopelta_ Ehr.
+
+_Actinoptychus cellulosa_ Ehr., H. L. Smith Sp. Typ., 384.
+
+Quite common in marine and brackish water and in the blue clay.
+
+Pl. 4, Figs. 1, 2, 4 and 6.
+
+
+ACTINOPTYCHUS VULGARIS VAR. INTERRUPTA N. VAR.
+
+Valve with fourteen sectors, the alternate ones divided by a smooth
+lanceolate space for about one-half the radius, forming with the smooth,
+circular umbilicus a seven pointed star. The sectors thus divided have
+coarser puncta in quincunx than the other sectors, ending in a smooth area
+near the margin, and also larger black puncta scattered from the centre to
+the semi-radius.
+
+Near A. vulgaris var. neogradensis Pant.
+
+Blue clay. Not common.
+
+Pl. 4, Fig. 5.
+
+
+{25}ACTINOPTYCHUS HELIOPELTA GRUN. VAR.?
+
+Valve circular, sectors, eight, umbilicus circular, without rays; border
+wide, cellular, with distinct rays. Inserted at a distance within the inner
+edge of the border are large processes, one on each of four alternate
+sectors, and two on each of the others. The sectors are cellulate and
+punctate.
+
+Near A. heliopelta var. versicolor Brun., which, however, in the specimen
+in my collection from Atlantic City (artesian well), has a greater number
+of processes and they are situated on the edge of the border.
+
+Outcrop at Buckshutem, N. J. Rare.
+
+Pl. 4, Fig. 3.
+
+It has been quite well determined, I think, that the typical forms of A.
+heliopelta occur at the base of the Miocene. At Rock Hall, Md., on the
+eastern shore of Chesapeake Bay, at a depth of from 21 to 130 ft., and at
+Wildwood, N. J., at a depth of from 78 to 179 ft., diatomaceous beds occur
+considered by Mr. Lewis Woolman (Geol. Surv. of N. J., 1898, pp. 116-121)
+"as synchronous in age," the former being deposited in the Delaware River
+Delta and the latter in the Chesapeake in post-miocene times. In each of
+these beds a small form of A. heliopelta is rarely found. The material at
+Buckshutem is post-miocene, and the form here figured shows a marked
+variation from the Miocene species and a gradual approach toward A.
+undulatus.
+
+
+POLYMYXUS L. W. BAIL. (1855)
+
+Valve circular, usually divided into fourteen sectors which are on the same
+plane at the centre, but the alternate ones are elevated into mammillated
+projections terminated by small processes on the margin. Zone view
+rectangular with undulations subconical, terminated by the processes.
+
+
+POLYMYXUS CORONALIS L. W. BAIL.
+
+Central space hyaline, rounded or slightly stellate, from which radiate
+rows of fine puncta in quincunx, shown in the figure only on the alternate
+elevations, the depressed interspaces being out of focus. The mammillae are
+stated by Bailey to vary from six to ten.
+
+Very rare in the blue clay (Walnut St. Bridge). Occurs also in the Wildwood
+deposit (Bull. Torrey Bot. Club, 1895, p. 261).
+
+Pl. 4, Fig. 7, and Pl. 5, Fig. 2.
+
+
+
+3. EUPODISCEAE
+
+_Aulacodiscinae._--Valves with mammiform elevations near the border
+surmounted by nipple-like processes.
+
+
+AULACODISCUS--THE ONLY GENUS AS ABOVE
+
+_Eupodiscinae._--Valves with ocelli.
+
+(1) _Actinocyclus._--Valve with one small ocellus; striae radial.
+
+(2) _Eupodiscus._--Valve with one or more ocelli; striae not radial.
+
+(3) _Auliscus._--Valve with large, elevated ocelli. Central area hyaline.
+Markings granular and costate.
+
+(4) _Pseudauliscus._--Valve with radiating granules. No central space.
+
+
+{26}AULACODISCUS EHR. (1844) em. RATTR. (1888)
+
+(aulax, a furrow, and discus)
+
+Valve usually circular, plane or with an elevated zone, frequently inflated
+beneath the processes; central space irregular or rounded, sometimes
+absent; markings granular, radial, sometimes in a reticulum.
+
+The genus comprises more than one hundred species most of which are fossil,
+and is represented in this locality by a single form, _A. argus_, included
+by Rattray in his section "Retiformes," distinguished by the presence of a
+reticulum.
+
+
+AULACODISCUS ARGUS (EHR.) SCHMIDT
+
+Frustule in zone view elliptical. Valve circular, 125-190 [mu] in diam.,
+closely covered with two kinds of markings, one, a mesh of large,
+radiating, angular cells, the outer plate, and the other, radiating rows of
+circular granules with hyaline spaces intervening and closer near the
+border, forming the inner plate which can occasionally be seen detached.
+Central space absent. The walls of the angular cells are crossed with fine
+lines and are probably composed of granules compressed so closely as to
+produce partial opacity, the depth of which depends in a measure not only
+on the superposition of the two plates, but on the relative closeness and
+thickness of the cell-walls. In a fully-developed specimen the effect is to
+produce more or less triangular cells containing three or four granules. In
+some cases the opacity is so great as to render detail invisible.
+
+In the figure the valve is supposed to be divided into three sectors,
+illustrating at "a" the lower plate, at "c" the combination of the upper
+and lower plates, and in the other sector the cellular mesh of the upper
+plate. Processes, usually three, quite robust and inserted at from
+one-fourth to one-fifth the length of the radius from the border which is
+striated on the inner side. A form with four processes is found in the
+lower blue clay.
+
+_Tripodiscus argus_ Ehr.
+
+_Eupodiscus argus_ (Ehr.) Wm. Sm.
+
+Not uncommon in the blue clay.
+
+Pl. 4, Fig. 8.
+
+
+ACTINOCYCLUS EHR. (1837)
+
+(actis, a ray, and cyclos)
+
+Valve circular or elliptical; surface flat at the centre, sloping toward
+the border. Central space usually evident, rounded or irregular. Markings
+rounded, granular, punctiform, in radial, or nearly radial, rows, sometimes
+fasciculate. A nodule, more or less evident, is found near the border which
+is usually striate.
+
+Chromatophores round discs or granules.
+
+
+ANALYSIS OF SPECIES
+
+
+  Valve circular, rows radial, hyaline lines at the border    barkleyi
+
+  Valve circular, rows fasciculate                            moniliformis
+
+  Valve elliptical                                            ellipticus
+
+The nodule is generally supposed to be a thickening of the cell-wall, and,
+in the opinion of Rattray, a projection outward, but "whether there may not
+be at the same time a slight inward protuberance is difficult to
+determine," though, as a rule, he seems to "think there is not."
+
+
+{27}ACTINOCYCLUS BARKLEYI VAR. AGGREGATA RATTR.
+
+Surface flat from centre to semi-radius. Central space irregular, sometimes
+with a few scattered granules. Markings round with central dots distinct,
+about 7 at the centre, decreasing in straight radial rows to 12 in 10 [mu]
+at the border, where they form moniliform striae. Border narrow with striae
+about 16 in 10 [mu]. Hyaline interspaces at the origin of the shorter rows,
+but not at equal intervals. At the border, linear hyaline spaces occur at
+somewhat irregular intervals between the moniliform striae owing to the
+termination of certain radial rows before they reach the circumference.
+Nodule small, from one-seventh to one-fourth the radius from the border.
+
+According to Rattray the distinction between A. ralfsii and A. barkleyi is
+partly in the absence of the zone arrangement of the hyaline spaces in the
+latter, and to the slight differences in the number of granules. The
+variety aggregata differs from the type form of barkleyi mainly in the
+distance of the nodule from the border. I have specimens from the blue clay
+material at Walnut St. Bridge, and from Smith's Island, in which the
+distance from the border in one case is, as stated above, quite different
+from that in the other. In specimens from Morris Cove, Conn., the locality
+referred to by Rattray, variations occur.
+
+Blue clay.
+
+Pl. 6, Fig. 1.
+
+In the figure the subulate hyaline spaces at the border are, in some
+instances, wider than usual.
+
+
+ACTINOCYCLUS MONILIFORMIS RALFS
+
+Surface flat, from centre to about five-sixths of the radius. Central space
+rounded, with one or more granules. Markings, 8 in 10 [mu], round, in
+radial rows, fasciculate, the oblique transverse rows irregular, very
+slightly decreasing until near the edge of the flattened zone, and then
+suddenly decreasing and appearing as decussating lines oblique to the
+border. Apiculi distinct, interfasciculate within the border. Nodule quite
+evident, surrounded by a rather wide irregular hyaline space on the margin
+of the flattened zone in the middle of the fasciculus. Border wide, with
+striae about 20 in 10 [mu].
+
+Blue clay. Port Penn. Not common.
+
+Pl. 6, Fig. 2.
+
+Equivalent to Actinocyclus ehrenbergii, H. L. S. Type Slide 10.
+
+In a valve from Port Penn, Delaware Bay, two nodules occur nearly opposite
+each other.
+
+
+ACTINOCYCLUS ELLIPTICUS VAR. DELAWARENSIS N. VAR.
+
+Valve rhombic-elliptical. Markings somewhat angular, 6 in 10 [mu] at the
+centre where they are sub-concentric, thence decreasing in lines radiating
+more or less toward the border, where they suddenly become punctiform,
+striae about 20 in 10 [mu]. Border equal to one-fifth the radius. A nodule
+is found on the inner side of the border. Apiculi apparently absent.
+
+The markings are larger than in the Richmond forms which are associated by
+Rattray with Actinocyclus ellipticus Grun. The form corresponds closely to
+Witt's Cestodiscus ovalis var.? (Witt, Polierschief. von
+Archangelsk-Kurojedowo, Pl. 8, Fig. 2), except as to the border. It does
+not answer to Van Heurck's figure or any other.
+
+Blue clay. Very rare.
+
+Pl. 3, Fig. 6.
+
+
+{28}EUPODISCUS EHR. (1844)
+
+(eu, well, pous, a foot, and discus)
+
+Valve circular, 45-117 [mu] in diam. (De Toni). Central space absent,
+surface plane with angular cells. At the border short, circular processes
+or ocelli.
+
+
+EUPODISCUS RADIATUS BAIL.
+
+Valve with radiating hexagonal cells, sometimes slightly curved toward the
+large ocelli inserted near the border which are hyaline at the centre.
+Border wide, coarsely striate.
+
+The number of ocelli heretofore recorded is four. Specimens with five
+processes are found in the artesian well at St. Augustine, Fla., and in
+material at Twelfth and Brandywine Sts. Mr. Hugo Bilgram has discovered
+valves with three and six ocelli.
+
+Not common in the blue clay, but abundant along the southern coast of the
+Atlantic states and the Gulf of Mexico.
+
+Not Eupodiscus radiatus Wm. Sm, which is Biddulphia smithii (Ralfs) V. H.
+
+Pl. 5, Fig. 3.
+
+
+AULISCUS EHR. (1843)
+
+(aulax, a furrow, referring to the grooves in certain species, according to
+De Toni, but preferably from auliscos, a small reed, referring to the
+processes?)
+
+Frustule cylindrical; zone with longitudinal rows of fine puncta. Valve
+circular or elliptical, plane except near the processes; central area
+hyaline, usually circular. Markings of two kinds, granules radiating or
+scattered and radiating, costate lines, prominent or indistinct. Processes,
+two or three, large, short, cylindrical, with hyaline surface, near the
+ends of the major axis in a line oblique to it.
+
+Auliscus is divided by Rattray into fourteen sections, defined chiefly by
+the character and arrangement of the markings. About eighty species are
+described, but as many of the forms are fossil, occuring in the Miocene of
+California, Oamaru and elsewhere, and as so few species are found in this
+locality, I shall refer but briefly to this division.
+
+
+  _Striolati._--No transverse median areas, striae
+    inconspicuous                                             punctatus
+
+  _Lineolati._--Markings distinct, pruinose, interrupted      pruinosus
+
+  _Costati._--Transverse median areas usually distinct,       sculptus
+     markings continuous, costate                             caelatus
+
+AULISCUS PUNCTATUS BAIL.
+
+Valve broadly elliptical, or suborbicular, covered with delicate
+interrupted striae radiating in sinuous lines to the circumference, more
+evident on the transverse median area; puncta 3 in 10 [mu], grouped into a
+rounded area on each side of the median line, elsewhere scattered. Central
+space rounded, processes two, large, suborbicular.
+
+Port Penn, Delaware River. Rare.
+
+Pl. 5, Fig. 6.
+
+
+AULISCUS PRUINOSUS BAIL.
+
+Valve elliptical, with distinct, interrupted, pruinose, irregular markings
+diverging in curved lines toward the circumference in the median part and
+converging toward the processes, interspersed with numerous darker markings
+having the appearance of apiculi. Central space nearly circular, sometimes
+with several granules. Processes large near the ends of the major axis and
+not oblique to it, or scarcely so, the edges with a crenulate border.
+
+Blue clay. Rather rare.
+
+Pl. 5, Fig. 8.
+
+
+{29}AULISCUS SCULPTUS (WM. SM.) RALFS
+
+Valve elliptical or subcircular, median areas distinct, rounded,
+circumscribed by coarse distant costae radiating near the border where they
+are more evident, and converging toward the processes. Central space
+rounded, sometimes indefinite. Processes, two, circular.
+
+Typical specimens show wide, coarse, distant costae, but, in some cases,
+the median areas are indistinctly outlined.
+
+Blue clay.
+
+Pl. 5, Fig. 5.
+
+
+AULISCUS CAELATUS BAIL.
+
+Valve elliptical or subcircular, with radiating costae, more evident around
+the median areas and at the border, converging toward the processes, with
+intermediate punctate radiating lines. Central space rounded or irregular.
+Processes circular.
+
+A. sculptus has coarser costae and the interspaces are hyaline, or
+apparently so, while in A. caelatus the punctate striae between the costae
+are more evident.
+
+Blue clay. Not uncommon.
+
+Pl. 5, Fig. 4.
+
+Fig. 7 is a small, indefinite form intermediate between A. sculptus and A.
+caelatus. The numerous variations in this genus make it difficult to
+satisfactorily differentiate the species. The size of the four above
+described varies from 40 to 150 [mu].
+
+
+PSEUDAULISCUS A. S. (1875) AND LEUDUGER-FORTMOREL (1879)
+
+Valve circular or subcircular, nearly flat or depressed at the centre.
+Central space not evident. Processes circular, with narrow border, near the
+circumference. Border narrow, striated. Markings granular, radiating,
+sometimes interspersed with striae and apiculi.
+
+Differs from Auliscus chiefly in the absence of a central space and costae.
+
+
+PSEUDAULISCUS RADIATUS (BAIL.) RATTR.
+
+Valve circular, or nearly so, flat. Central area with scattered granules
+radiating and increasing in size outward in diverging rows toward the
+border which is coarsely striated. Processes, two, circular. Two small
+apiculi are inserted at about one-fifth the radius from the border near the
+ends of the minor axis.
+
+Blue clay. Rare.
+
+Pl. 5, Fig. 9.
+
+The apiculi are not always figured. They appear in a number of specimens
+from the Miocene of Maryland, Atlantic City, Harvey Cedars and Newbern.
+
+
+PSEUDAULISCUS SPINOSUS (CHRISTIAN) RATTR.
+
+Valve subcircular or slightly quadrangular, depressed at the centre and
+rising to an elevated zone near the border, the two zones separated by a
+distinct line. The inner zone indistinctly reticulate with fine puncta
+radiating from the centre and apiculi at intervals. The outer zone with
+smaller apiculi surrounding the inner zone and with intermingled rows of
+fine puncta and interrupted diverging striae. Near each end of the minor
+axis is a rather long, robust spine inserted at one-fourth the radius from
+the border which is narrow and striated. Processes circular, close to the
+circumference.
+
+_Auliscus spinosus_ Christian.
+
+Blue clay. Rare.
+
+Pl. 5, Fig. 10.
+
+The genus is named by Schmidt, described by Leuduger-Fortmorel and
+emendated by Rattray.
+
+
+
+{30}BIDDULPHIOIDEAE
+
+BIDDULPHIEAE
+
+(_a_) _Triceratiinae._--Frustule cylindrical or prismatic, with three or
+more sides.
+
+(_b_) _Biddulphiinae._--Frustule cylindroid; valve with ends elevated into
+round processes or long horns.
+
+(_c_) _Anauleae._--Valve elliptical, lunate or triangular, with internal
+septa.
+
+(_d_) _Euodieae._--Frustule cuneate in zone view; valve lunate.
+
+
+
+(_a_) TRICERATIINAE
+
+(1) _Ditylum._--Frustule imperfectly siliceous. Zone with numerous
+divisions. Valve with central spine.
+
+(2) _Trinacria._--Processes with sharp spines.
+
+
+DITYLUM BAIL. (1861)
+
+(dis, two, and tyle, a swelling, referring to the outline of the frustule)
+
+Frustule quadrangular, convex at the ends. Valve triangular, with
+undulating sides, the angles ending in a sharp point surmounted by a
+bristle. Surface of valve convex at centre from which projects a long stout
+spine.
+
+
+DITYLUM INTRICATUM (WEST) GRUN.
+
+Valve with the angles separated from the central part by lines imitating
+septa. Surface with radiating lines of fine puncta.
+
+Blue clay. Rare.
+
+Pl. 6, Fig. 4.
+
+Detached valves only have been found in the blue clay. The form is regarded
+as but slightly siliceous and, therefore, the zone or girdle not being
+found in the fossil deposits, I am unable to illustrate it from material in
+the vicinity. On Plate 38, Figs. 6 and 7, I have sketched the zone and
+valve views of specimens found recently at Vera Cruz and labelled by H. L.
+Smith Triceratum intricatum West. I can find no difference between the
+recent and fossil forms of the valves. The zone is covered with fine puncta
+in quincunx, not visible under ordinary illumination.
+
+The form as figured in Plate 6 corresponds to the figure of Lithodesmium
+undulatum Ehr. in Van Heurck, and West, in describing the Triceratium
+undulatum Wm. Sm. (figured as T. striolatum), thought that his T.
+intricatum was distinct from Ehrenberg's form on the ground that the latter
+came from the "Bermuda" (Nottingham) earth and must be strongly siliceous.
+Lithodesmium is characterized by the envelopment of the frustules by a
+cellular membrane which does not appear, evidently, in Ditylum. D.
+brightwellii is distinguished by its crown of spines on the margin;
+otherwise it closely resembles D. intricatum.
+
+
+TRINACRIA HEIB. (1863)
+
+(treis, three, and acra, a point)
+
+Valve triangular, angles elevated into spines. Cells at the margin large.
+
+
+TRINACRIA PILEOLUS (EHR.) GRUN.
+
+Valve with concave sides. Surface concave with unequal punctiform and
+scattered markings with central dots. Cells at the margin large, rounded.
+At the angles, which vary in elevation, a few puncta are seen.
+
+_Triceratium pileolus_ Ehr.
+
+Blue clay. Rare.
+
+Pl. 6, Fig. 9.
+
+
+
+{31}(_b_) BIDDULPHIINAE
+
+BIDDULPHIA GRAY (1831) em. VAN HEURCK (1885)
+
+(a genus, constituted from Conferva biddulphiana of the English Botany,
+named after a Miss Biddulph)
+
+Frustule prismatic or subcylindrical, concatenate, filamentous, or in
+zig-zag, or, as usually found, free. Zone well developed. Valve triangular,
+polygonal, elliptic or subcircular, convex, more or less elevated at the
+angles into processes or horns. Markings cellular or punctate.
+Chromatophores, small plates of various forms.
+
+
+KEY TO THE SPECIES
+
+
+  Valves costate                                              biddulphiana
+
+  Valves not costate:
+
+    Markings cellular, angles elevated into horns             favus
+
+                       angles not elevated                    antediluviana
+
+    Markings punctate, angles with subconical processes and
+      long spines                                             granulata
+
+        spines short                                          rhombus
+
+        spines minute                                         smithii
+
+        processes truncate, valve elliptical                  turgida
+
+                            valve orbicular                   laevis
+
+        processes absent, valve divided by irregular lines    alternans
+
+        not so divided                                        reticulum
+
+
+BIDDULPHIA BIDDULPHIANA (SMITH)
+
+Frustule quadrangular with convex ends and rounded angles. Valve elliptical
+with undulated sides, divided by septa into three or more sections.
+Processes large, rounded, globular or subconical. Zone varying in width.
+Surface with rounded reticulations in longitudinal and transverse rows,
+except at the centre where they are concentric and smaller.
+
+_Conferva biddulphiana_ Smith (English Botany, 1807, Pl. 1762, upper
+figures).
+
+_Diatoma biddulphianum_ Ag.
+
+_Biddulphia pulchella_ Gray.
+
+Blue clay. Hoboken Tunnel. Along the coast.
+
+Pl. 7, Figs. 1, 2, 3, and 4.
+
+Quite variable in size and number of septate divisions. Fig. 3 is an
+unusual form with narrow zone, having but one row of large reticulations,
+evidently a young frustule.
+
+
+BIDDULPHIA FAVUS (EHR.) V. H.
+
+Frustule quadrangular, elevated at the angles into subconical processes
+oblique to the longitudinal axis. Valve triangular or quadrangular, plane,
+of two layers, the outer layer composed of large hexagonal cells in rows
+parallel to the sides, the inner of small puncta radiating from the centre.
+Zone punctate in quincunx, never found open.
+
+_Triceratium favus_ Ehr.
+
+Blue clay. Common along the coast.
+
+The quadrangular form occurs only southward.
+
+Pl. 6, Fig. 6. At "a" a cell showing the lower punctate layer. Pl. 40, Fig.
+16, a transverse section of a portion of the valve showing the cellular
+structure and the punctated lower stratum.
+
+
+{32}BIDDULPHIA ANTEDILUVIANA (EHR.) V. H.
+
+Frustules quadrangular, sometimes united in zig-zag chains. Valve
+quadrangular with more or less concave sides, sometimes cruciform. Surface
+with angular cells arranged in concentric and radiating lines increasing
+toward the circumference. At each angle is a large, rounded process, which,
+as well as the secondary layer, scarcely visible, is finely punctate.
+
+_Amphitetras antediluviana_ Ehr.
+
+_Amphitetras tessellata_ Shad.
+
+Blue clay. Rare.
+
+Pl. 6, Fig. 3.
+
+A cruciform variety occurs at Pensauken, N. J., artesian well (Coll. F. J.
+Keeley).
+
+
+BIDDULPHIA GRANULATA ROPER
+
+Valve elliptical-lanceolate, convex, with diagonal rows of puncta 12 in 10
+[mu] and sometimes with small scattered spurs. Processes inflated at the
+base, obtuse at the ends, which are curved outward toward alternate sides.
+Near each process and on opposite sides of the longitudinal axis is placed
+a stout spine bent or curved inward near the middle. Connective zone with
+diagonal rows of puncta smaller than those on the valve.
+
+Pavonia, N. J., artesian well. Fossil in the Pleistocene. Along the coast.
+Not common.
+
+Pl. 7, Fig. 6.
+
+
+BIDDULPHIA RHOMBUS (EHR.) WM. SM.
+
+Valve rhomboidal, sometimes triangular, with subconical processes. Surface
+convex with hexagonal reticulations, 7-9 in 10 [mu], irregular at the
+centre and radiating to the circumference. Minute spurs are scattered over
+the surface, and on each side are usually two or three short spines.
+
+Common along the coast and fossil in the Miocene and later deposits.
+
+Pl. 7, Fig. 5 (somewhat inclined, as usually seen).
+
+
+BIDDULPHIA SMITHII (RALFS) V. H.
+
+Valve orbicular, convex, with reticulations 5 in 10 [mu] radiating from the
+centre and decreasing toward the margin and processes which are truncate. A
+short spine is found on each side half way between the processes. Zone
+narrow with fine puncta 12 in 10 [mu] in longitudinal rows.
+
+_Cerataulus smithii_ Ralfs.
+
+_Eupodiscus radiatus_ Wm. Sm.
+
+Blue clay. Along the coast southward.
+
+Pl. 7, Fig. 8.
+
+
+BIDDULPHIA TURGIDA (EHR.) WM. SM.
+
+Valve elliptical or orbicular, surface convex. Processes very large,
+cylindrical, placed obliquely and inclined by the torsion of the frustule.
+Between the processes are two stout spines, one on each side, frequently
+forked at the ends. Puncta fine, irregular at the centre and radiating
+toward the circumference.
+
+_Cerataulus turgidus_ Ehr.
+
+Blue clay. Along the coast. Quite variable in size.
+
+Pl. 7, Fig. 7.
+
+
+{33}BIDDULPHIA LAEVIS EHR.
+
+Valve suborbicular or triangular, with short, truncate processes. Surface
+with fine puncta about 13 in 10 [mu] radiating in straight or curved lines
+toward the circumference and with fine spurs at intervals. Nearer one
+process than the other, and about half way between centre and
+circumference, are two small spines, one on each side. Quite variable in
+size.
+
+Blue clay. Common along the coast.
+
+Pl. 7, Fig. 9.
+
+Fig. 10 (magnification about 260 diameters only) illustrates sporangial
+frustules discovered by Mr. T. Chalkley Palmer at Reedy Island, Delaware
+River. In frustules having a cylindrical form, the endochrome lines the
+cell-walls in the form of granules which become congregated toward the
+centre in the sporangia.
+
+
+BIDDULPHIA ALTERNANS (BAIL.) V. H.
+
+Valve triangular or, rarely, quadrangular, with sides straight or slightly
+concave, usually unequal. Angles obtuse, separated from the centre by
+costate lines. Surface with puncta of irregular shape, large at the centre,
+with smaller puncta interspersed. In many valves several lines appearing
+like costae extend inward from the border in various directions. Angles
+with small puncta in transverse and longitudinal rows.
+
+_Triceratium alternans_ Bail.
+
+Blue clay. Along the coast.
+
+Pl. 6, Fig. 7 and probably Fig. 8.
+
+
+BIDDULPHIA RETICULUM (EHR.)
+
+Frustule quadrangular. Valve triangular with straight or concave sides and
+rounded angles. Surface convex at the centre and angles. Markings of
+unequal size, mostly larger at the centre, scattered; at the angles, small
+puncta in longitudinal rows.
+
+_Triceratium sculptum_ Shad.
+
+_Triceratium punctatum_ Br.
+
+_Triceratium obtusum_ Br.
+
+For explanation of the synonymy see "Biddulphoid Forms of N. A. Diat.,"
+Proc. Acad. Nat. Sci., 1900, p. 724.
+
+Blue clay. Along the coast.
+
+Pl. 6, Fig. 5.
+
+
+
+(_c_) ANAULEAE
+
+EUNOTOGRAMMA WEISSE (1854)
+
+(eu, well, noton, a back, and gramma)
+
+Frustule quadrangular. Valve elliptical or lunate divided by septa which
+constrict the margin. Surface flat with punctate markings.
+
+
+EUNOTOGRAMMA LAEVE GRUN.
+
+Valve lunate with obtuse ends. Septa, from four to eleven or more. Surface
+with puncta in transverse and longitudinal rows, sometimes indistinct and
+scattered.
+
+Shark River. Rare. More common southward. Fossil at Buckshutem, N. J.
+
+Pl. 7, Fig. 11, and Pl. 10, Fig. 15.
+
+I am unable to distinguish between E. laeve and E. debile, as intermediate
+forms occur.
+
+
+{34}TERPSINOE EHR.
+
+(terpsinoos, gladdening?)
+
+Frustules quadrangular, adnate in filaments, usually free. Valve elliptical
+or triangular, with undulating sides divided by septa into three or more
+sections.
+
+
+TERPSINOE AMERICANA (BAIL.) RALFS
+
+Valve lobed at each end or angle. Central space rounded, hyaline. Surface
+with fine puncta in radiating lines.
+
+Blue clay. Not common.
+
+Pl. 6, Fig. 10.
+
+
+TERPSINOE NOVAE-CAESAREAE BOYER
+
+Valve triangular, with concave sides and broad angles equally three-lobed,
+separated from the central part by septa. Central space small or absent.
+Puncta delicate, radiating or scattered. L. of side 62 [mu].
+
+Pleistocene clay at Buckshutem, N. J. Fossil at Wildwood, N. J.
+
+T. americana, forma trigona Pant.? (Le Diatomiste, Vol. 2, p. 207.)
+
+Pl. 6, Fig. 11.
+
+
+
+(_d_) EUODIEAE
+
+EUODIA BAIL. (1860)
+
+(derivation uncertain; apparently from euodia, fragrant, probably a
+euphemism)
+
+Frustule in zone view cuneate. Valve semi-lunate, coscinodiscoid.
+
+
+EUODIA GIBBA BAIL.
+
+Valve with rounded markings, larger and scattered at the centre, radiating
+at the circumference and in indefinite straight rows at the semi-radius.
+
+Delaware Bay (Mann).
+
+Pl. 5, Fig. 1.
+
+I have not seen this in the Philadelphia material. The figure is drawn from
+a specimen from the Gulf Stream, S. Atlantic.
+
+
+
+{35}PENNATAE
+
+Valve zygomorphous. Structure pinnate, not concentric. Valve divided either
+by a true raphe or cleft or by a linear space or line imitating a raphe.
+
+Divided into three Groups:
+
+1. _Fragilarioideae._--Valves without a raphe; usually with a pseudoraphe
+or median line.
+
+2. _Naviculoideae._--Either one or both valves with a true raphe.
+
+3. _Surirelloideae._--Valves in which the raphe is concealed near the
+margin on one or both sides of each valve in a more or less elevated keel
+or wing.
+
+
+
+FRAGILARIOIDEAE
+
+(_a_) _Tabellarieae._--Valve symmetrical with respect to both the
+longitudinal and transverse axes; septate, not cuneate.
+
+(_b_) _Meridioneae._--Valve symmetrical with respect to the longitudinal
+axis, asymmetrical to the transverse axis, cuneate, finely striated.
+
+(_c_) _Fragilarieae._--Valve of varied shape, not cuneate; costate or with
+transverse rows of puncta.
+
+
+
+(_a_) TABELLARIEAE
+
+Frustule in zone view rectangular, in valve view linear or
+linear-elliptical, sometimes constricted in the middle, symmetrical to both
+axes, not cuneate; with two or more septa or annuli.
+
+Chromatophores numerous, granular.
+
+_Rhabdonema._--Frustules with numerous septate partitions having one or
+several foramina. Transverse costae or rows of coarse puncta.
+
+_Tabellaria._--Frustules with two to six nearly straight septa. Transverse
+striae subtly punctate.
+
+_Grammatophora._--Frustules with two sinuate perforate curved septa.
+Transverse striae subtly punctate.
+
+_Striatella._--Frustules with alternate partitions, septate or partly so.
+
+_Attheya._--Frustules not septate but with numerous annuli.
+
+
+RHABDONEMA KUETZ. (1844)
+
+(rhabdos, a rod, and nema, a thread)
+
+Frustules quadrangular, concatenate, composed of numerous septate
+partitions with transverse costae or rows of puncta. Valves elliptical,
+with a pseudoraphe and transverse apparent costae and punctate lines; the
+partitions with one or several foramina.
+
+Chromatophores in rosettes of various kinds (Karsten); usually parallel to
+the septa.
+
+
+RHABDONEMA ARCUATUM (LYNG.) KUETZ.
+
+Valve hyaline at the ends, with transverse rows of puncta producing the
+appearance of costae between the rows; pseudoraphe distinct; foramen
+single.
+
+_Diatoma arcuatum_ Lyngbye.
+
+Common along the coast.
+
+Pl. 8, Figs. 1, 2, and 3; Pl. 40, Fig. 10.
+
+{36}According to T. H. Buffham (Jour. Quek. M. C., Series 2, Vol. 2, p.
+131), the frustules are of two kinds, those in which the length and breadth
+are the same and those which are much lengthened, with a wide hyaline
+girdle frequently in the middle. At the time of fructification the smaller
+frustules are attached to a larger one which produces a sporangium at the
+end of the girdle from which the other end of the frustule has disappeared,
+or, if the two halves of the frustule remain, two sporangia are formed.
+
+
+RHABDONEMA MINUTUM KUETZ.
+
+Frustules small; valve not smooth at the ends, elliptical or
+lanceolate-elliptical, with transverse rows of puncta; pseudoraphe
+distinct. Foramen single, alternating above and below in adjoining
+partitions.
+
+Common in the blue clay and along the coast.
+
+Pl. 8, Fig. 7 and Pl. 38, Fig. 11.
+
+
+RHABDONEMA ADRIATICUM KUETZ.
+
+Valve linear-lanceolate, with smooth angles; rows of puncta transverse, the
+intervals appearing as costae, as in arcuatum. Foramina, three.
+
+Blue clay in the Pensauken and Pavonia deposits and along the coast.
+
+Pl. 8, Figs. 4, 5 and 6.
+
+
+TABELLARIA EHR. (1839)
+
+(tabella, a tablet)
+
+Frustules quadrangular, adnate in filaments, frequently found in zig-zag
+chains, united by a gelatinous isthmus, at length separating. Valve linear,
+inflated in the middle and at the ends; striae transverse.
+
+Chromatophores numerous, small, along the zones.
+
+
+TABELLARIA FENESTRATA (LYNG.) KUETZ.
+
+Valve elongated; pseudoraphe narrow; transverse striae faint. In the zone
+view a straight septum is shown at each end of a valve.
+
+Common, especially in the cedar swamps and ponds of the Pine Barren region,
+N. J.
+
+Pl. 8, Figs. 11 and 12.
+
+
+TABELLARIA FLOCCULOSA (ROTH) KUETZ.
+
+Valve linear, with median inflation larger than the terminal; pseudoraphe
+rather broad in the middle; transverse striae subtly punctate. In zone view
+the frustules are quadrangular, or nearly so, with about six sometimes
+curved septa at one end alternating with those on the other end.
+
+_Conferva flocculosa_ Roth.
+
+Common especially in the Pine Barrens of New Jersey.
+
+Pl. 8, Figs. 8, 9 and 10.
+
+
+GRAMMATOPHORA EHR. (1840)
+
+(from gramma, a letter, and phoreo, I bear)
+
+Frustules quadrangular, adnate, in zig-zag, united by an isthmus, or,
+usually, found free; divided by two sinuate and perforate curved septa.
+Valve linear or oblong, sometimes with sinuate sides, and with a
+pseudoraphe and transverse punctate lines.
+
+Chromatophores granular.
+
+
+{37}GRAMMATOPHORA MARINA (LYNG.) KUETZ.
+
+Valve linear-elliptical, with smooth apices. Septum with a wide undulation
+near its origin, thence straight and incrassate at the end. Striae in
+quincunx, 18-21 in 10 [mu].
+
+_Diatoma marinum_ Lyngbye.
+
+Blue clay. Along the coast.
+
+Pl. 8, Figs. 17 and 18.
+
+
+GRAMMATOPHORA MARINA VAR. SUBTILISSIMA (BAIL.) V. H.
+
+Valve linear, slightly constricted near the smooth apices. Septum undulated
+near its origin and then straight, incrassate at the end. Puncta in
+quincunx very subtle, 34-36 in 10 [mu].
+
+_Grammatophora subtilissima_ Bail.
+
+Grammatophora oceanica var. subtilissima (Bail.) V. H., according to De
+Toni. G. marina and G. oceanica are united by some authors; the latter has
+more subtle striae.
+
+Along the coast.
+
+Pl. 8, Figs. 13 and 14.
+
+
+GRAMMATOPHORA SERPENTINA RALFS
+
+Valve linear-elliptical, long, measuring to 150 [mu] (De Toni); smooth at
+the apices. Septum with numerous undulations and hooked at the apex. Puncta
+in quincunx, 17 in 10 [mu].
+
+Along the coast.
+
+Pl. 8, Fig. 21.
+
+
+GRAMMATOPHORA ANGULOSA VAR. HAMULIFERA (KUETZ.) GRUN.
+
+Frustule nearly quadrate; valve with rounded but not smooth apices. Septum
+bent into a sharp angle near its origin and ending in a broad hook. Puncta
+in transverse rows, 14 in 10 [mu].
+
+Along the coast.
+
+Pl. 8, Figs. 15 and 16.
+
+
+GRAMMATOPHORA ISLANDICA EHR.
+
+Frustule oblong; valve elliptical-lanceolate. Septum robust with several
+undulations and hooked at the end. Pseudoraphe distinct; transverse rows of
+puncta, 10 in 10 [mu].
+
+Reported by Kuetzing in the Atlantic Ocean and by Kain at Belmar, N. J. I
+have not found it on our coast and I believe, in some cases, it has been
+confused with _G. angulosa_ var. _hamulifera_. The figure is drawn from an
+Iceland form in H. L. Smith T. S., 186.
+
+Pl. 8, Figs. 19 and 20.
+
+
+STRIATELLA AG. (1832)
+
+(dim. of stria, referring to the lines on the frustule)
+
+Frustules tabulate, adnate in short, stipitate filaments, scarcely
+siliceous, divided into partitions, septate or partly so at alternate ends.
+
+
+{38}STRIATELLA UNIPUNCTATA (LYNG.) AG.
+
+Frustules with numerous bent septa extending the entire length. Valve
+lanceolate, somewhat unsymmetrical, subtly punctate, with pseudoraphe quite
+distinct.
+
+"The specific name is derived from the appearance of the endochrome which
+in the living specimen is invariably collected in a central mass with
+slender threads radiating in all directions toward the cell-wall" (Wm.
+Sm.). Pyrenoids cuneate, in the centre of the endochrome, numerous.
+
+Long Island Sound and along the coast.
+
+Pl. 8, Figs. 22 and 23.
+
+
+STRIATELLA INTERRUPTA (EHR.) HEIB.
+
+Frustules quadrangular, with robust alternate septa extending to the
+middle. Puncta in quincunx, 22 in 10 [mu].
+
+_Tessella interrupta_ Ehr.
+
+Very rare along the coast.
+
+Pl. 8, Fig. 24. (From a form found at Stonington, Conn.)
+
+
+ATTHEYA WEST (1860)
+
+(named after Thomas Atthey)
+
+Frustules quadrangular, tabulate, with numerous annuli. Valve
+elliptical-lanceolate, with a pseudoraphe and a central punctum. Extending
+from each end is a strong spine half as long as the valve.
+
+
+ATTHEYA DECORA WEST
+
+The only species. Diagnosis of the genus. The valves are imperfectly
+siliceous, scarcely visible in balsam.
+
+Very local. Abundant at Shark River, N. J.
+
+Pl. 8, Fig. 25.
+
+
+
+(_b_) MERIDIONEAE
+
+Valve symmetrical in zone and valve view along the sagittal line, but
+asymmetrical to the transverse axis, cuneate. In zone view sometimes with
+wedge-shaped septa. Valve finely striated, without central and usually
+without terminal nodules; a pseudoraphe present.
+
+_Licmophora._--Frustules cuneate in stipitate fan-shaped fascicles.
+
+_Meridion._--Frustules cuneate in spiral fascicles.
+
+
+LICMOPHORA AG. (1827)
+
+(licmos, a fan, and phoreo, I bear)
+
+Frustules wedge-shaped, joined together into fan-shaped, stipitate
+fascicles. Valve cuneate, rounded at both ends, septate. Chromatophores
+granular, round or oval in our species.
+
+
+{39}ANALYSIS OF SPECIES
+
+(In accordance, so far as it relates to our species, with the
+classification of C. Mereschkowsky, Diagnoses of New Licmophorae, Nuova
+Notarisia, 1901.)
+
+
+  Placatae--valve narrow, striae very fine, septa superficial flabellata
+
+  Dubiae--valve bacilliform, septa shallow, frustule with
+    thick walls                                               ovulum
+
+  Paradoxae--valve with lower end produced, striae fine,      paradoxa
+    pseudoraphe distinct, septa deep                          gracilis
+                                                              tincta
+                                                              baileyi ?
+
+  Lyngbyeae--valve narrow, attenuated at both ends, distinct,
+    septa deep                                                lyngbyei
+
+  Peristriatae--valve broad, pseudoraphe wide, striae robust  ehrenbergii
+
+
+LICMOPHORA FLABELLATA (CARM.) AG.
+
+Frustule elongate, narrow; valve narrow, lanceolate-cuneate, enlarged at
+the base; striae very fine, 30 in 10 [mu].
+
+_Echinella flabellata_ Carm.
+
+_Licmophora splendida_ Wm. Sm.
+
+Common along the coast.
+
+Pl. 9, Figs. 1 and 2.
+
+
+LICMOPHORA OVULUM MER.
+
+Valve ovate, attenuated to the rounded inferior apex; pseudoraphe
+indistinct, striae fine, 24 in 10 [mu]. Zone view broad, cuneate, angles
+rounded, inferior apex broad; frustule robust, septa superficial, straight.
+(Mereschkowsky, in part.)
+
+Atlantic City. Common.
+
+Pl. 9, Figs. 8 and 9.
+
+
+LICMOPHORA PARADOXA (LYNG.) AG.
+
+Frustule broad, with rounded angles; septa curved; valve ovate, inferior
+apex produced. Pseudoraphe distinct; striae varying from 25 below to 30
+above in 10 [mu].
+
+_Echinella paradoxa_ Lyng.
+
+_Rhipidophora paradoxa_ Kuetz.
+
+Along the coast.
+
+Pl. 9, Figs. 6 and 7.
+
+
+LICMOPHORA GRACILIS (EHR.) GRUN.
+
+Frustule cuneate, narrow, with sinuate margin; valve clavate, linear at the
+base; striae, 20 to 22 in 10 [mu].
+
+New Rochelle. Along the coast.
+
+Pl. 9, Fig. 11.
+
+
+LICMOPHORA GRACILIS VAR. ELONGATA (KUETZ.) DE TONI
+
+As in the type, but more graceful and with deeper septa.
+
+_Rhipidophora elongata_ Kuetz.
+
+Along the coast. Not common.
+
+Pl. 9, Figs. 12 and 13.
+
+
+{40}LICMOPHORA TINCTA (AG.) GRUN.
+
+Frustules cuneate, narrow, usually found in twos. Valve clavate, hyaline,
+rather broad at the base; septa moderately deep; pseudoraphe indistinct;
+striae, 27 at the base, 30 in the middle and 33 at the apex in 10 [mu].
+
+_Gomphonema tinctum_ Ag.
+
+Along the coast. Abundant from about the middle of July to the middle of
+August.
+
+Pl. 9, Figs. 14 and 15.
+
+
+LICMOPHORA BAILEYI (EDW.) GRUN.
+
+Frustule broadly cuneate or with convex margins, rarely almost orbicular;
+valve spatulate or ovate with slender, produced base; septa very deep;
+pseudoraphe distinct; striae 20 in 10 [mu].
+
+_Podosphenia baileyi_ (Edw.) Lewis.
+
+Long Island Sound and upper coast of New Jersey.
+
+This form is placed in a doubtful position by Mereschkowsky. As it
+corresponds more closely to the Paradoxae, it is placed here provisionally.
+The girdle face and apex of the valve are round, the pseudoraphe is
+distinct and the septa deep, but the stipe is short.
+
+Pl. 9, Fig. 10 and Pl. 38, Figs. 3 and 4.
+
+
+LICMOPHORA LYNGBYEI (KUETZ.) GRUN.
+
+Frustule cuneate, slightly rounded at the angles. Valve oblanceolate;
+pseudoraphe distinct; septa deep; striae, 12 in 10 [mu] below, and 16 in 10
+[mu] above.
+
+_Podosphenia lyngbyei_ Kuetz.
+
+Along the coast.
+
+Pl. 9, Figs. 3 and 4.
+
+
+LICMOPHORA EHRENBERGII (KUETZ.) GRUN.
+
+Frustule cuneate, broad. Valve obovate-lanceolate; pseudoraphe wide; striae
+coarse, 8 in 10 [mu], moniliform.
+
+_Podosphenia ehrenbergii_ Kuetz.
+
+Along the coast.
+
+Pl. 9, Fig. 5.
+
+
+MERIDION AG. (1824)
+
+(merizo, I divide)
+
+Frustules in zone view cuneate, adnate in circular or spiral fasciae, at
+length becoming free. Valve symmetrical with respect to the longitudinal
+axis, more or less cuneate; costae and striae transverse.
+
+Chromatophores numerous, small, elongated, in irregular rows on the zone
+(Pfitzer).
+
+
+MERIDION CIRCULARE (GREV.) AG.
+
+Transverse costae coarse, variable in number and distance apart, sometimes
+interrupted or indistinct; striae interstitial, 16 in 10 [mu].
+
+In springs and small streams of pure water.
+
+_Echinella circularis_ Grev.
+
+{41}Meridion constrictum Ralfs, sometimes given as a variety of M.
+circulare, differs only in the constriction below the apex. The two kinds
+of frustules are usually found growing together and as the variation is
+often extremely slight they are here included under the earlier name.
+
+Pl. 10, Figs. 1, 2 and 3.
+
+Fig. 1 represents the constricted form which is the more common. Fig. 3 is
+a sporangial form.
+
+The sporangial frustules vary in shape and size, some being long and
+slender, others clavate, but they are all more or less tumid in the middle,
+with costae more indefinite than in perfect valves. All gradations occur,
+one end becoming shorter until the valve has the shape of the variety known
+as constrictum. It would seem, therefore, that the non-constricted form is
+a passage from the sporangial to the smaller or adult form, or is of no
+specific importance. All forms are found living together. The adult
+frustules are the smaller ones; it is from them that the sporangia are
+produced.
+
+Meridion intermedium H. L. Smith (Amer. Quart. Mic. Jour., Vol. 1, p. 12)
+is characterized by less evident costae and is more delicate in general
+appearance. Some forms are capitate and others are not. Prof. Smith
+compares the M. intermedium with Peronia erinacea Breb. and Arnott which he
+has named M. erinaceum, hitherto found only in Europe, and points out the
+relation of the two forms to Licmophora. An examination of the H. L. S.
+type slides of the two diatoms proves that Peronia has very delicate costae
+and a distinct pseudoraphe not noticeable in Meridion. On the slide of
+Peronia are frustules exactly similar to certain of the sporangial
+variations of M. circulare.
+
+The fan-like arrangement of Licmophora, the marine form, and the circular
+chains of Meridion, the fresh-water genus, are similar. Both are stipitate
+at the beginning of their growth.
+
+
+
+(_c_) FRAGILARIEAE
+
+Divided into three sections:
+
+_Diatominae._--Valve circular, elliptical to linear, quadrate or cruciform,
+with transverse costae; without raphe, a pseudoraphe sometimes wanting.
+
+_Fragilariinae._--Valve elongate, with small central and terminal
+elevations, without costae but with transverse punctate striae; without
+genuine central nodule.
+
+_Eunotiinae._--Valve lunate; a raphe sometimes partially formed with
+terminal nodules near the edges.
+
+
+
+DIATOMINAE
+
+_Diatoma._--Frustules in filaments. Valve linear or elliptical, costate.
+
+_Plagiogramma._--Frustules in fasciae or free. Valve costate.
+
+_Opephora._--Valve costate, with an inner punctate stratum.
+
+
+DIATOMA DE CANDOLLE (1805) em. HEIB. (1863)
+
+(diatemno, I cut in two)
+
+Frustules oblong or quadrate, adnate in filaments, attached by alternate
+angles and finally separating. Valve linear or elliptical, with transverse
+costae and rows of puncta and a pseudoraphe.
+
+Chromatophores large granules without definite arrangement. (See Pl. 40,
+Fig. 11.)
+
+
+{42}DIATOMA VULGARE BORY.
+
+Valve elliptical-lanceolate, with apices sometimes rostrate or capitate;
+pseudoraphe narrow; costae, 5 in 10 [mu].
+
+Common everywhere in pure fresh water and extremely variable.
+
+Pl. 10, Figs. 9 and 10.
+
+Var. elongatum (Ag.) = var. ehrenbergii (Kuetz.)--elliptical-lanceolate,
+constricted near the apex.
+
+Var. grande (Wm. Sm.) Grun.--linear, elongated, constricted near the
+apices.
+
+Pl. 10, Fig. 4.
+
+Both of these varieties, with numerous intermediate forms, are abundant
+near Newtown Square. Varieties of Grunow, known as breve, ovate-lanceolate;
+productum, ovate-lanceolate with produced apices; capitulatum, lanceolate
+with capitate extremities, are mingled together in the same gathering.
+
+
+DIATOMA ANCEPS (EHR.) KIRCHN.
+
+Valve linear with rostrate apices; costae robust; striae delicate, 20 in 10
+[mu]. Zone view quadrangular.
+
+Common in fresh water.
+
+Pl. 10, Figs. 5 and 6. Fig. 11, Pl. 40, shows frustules containing the
+nuclei and chromatophores.
+
+
+DIATOMA HIEMALE (LYNG.) HEIB.
+
+Valve ovate-lanceolate to lanceolate; apices obtuse, not produced. Costae
+not numerous, robust; striae moniliform. Zone view quadrate, the costae as
+septa deeply dividing the valve into convex elevations.
+
+Common in springs.
+
+Pl. 10, Figs. 7 and 8.
+
+In all species of Diatoma a punctum, or pore, is observed, usually at
+alternate ends of the two valves, by means of which a communication exists
+between adjoining frustules and causes them to adhere in zig-zag chains
+when partially separated.
+
+
+PLAGIOGRAMMA GREV. (1859)
+
+(plagios, on the side, and gramma, a letter)
+
+Frustules quadrangular, adnate in fasciae, or free. Valve linear,
+elliptical, or elliptical-lanceolate, divided by two or more median and two
+terminal costae or with a central and two terminal hyaline spaces.
+
+
+  Valve with two median and two terminal costae:
+
+    Linear, pseudoraphe distinct                              pygmaeum
+
+    Linear, with striae at the ends                           wallichianum
+
+    Ovate-lanceolate                                          obesum
+
+  Valve without costae but with central and terminal
+      nodules: pseudoraphe absent                             tessellatum
+
+
+{43}PLAGIOGRAMMA PYGMAEUM GREV.
+
+Valve linear-elliptical; pseudoraphe distinct; rows of granules transverse,
+usually six in each compartment, moniliform, three on each side.
+
+Blue clay. Not common.
+
+Pl. 10, Fig. 13.
+
+
+PLAGIOGRAMMA WALLICHIANUM GREV.
+
+Valve linear, rounded at the ends; pseudoraphe absent; transverse rows of
+granules, six or seven in each compartment, and two or three rows of
+smaller granules at each end.
+
+Blue clay. Not common.
+
+Pl. 10, Fig. 14.
+
+
+PLAGIOGRAMMA OBESUM GREV.
+
+Valve rhombic-lanceolate, the costae scarcely visible; pseudoraphe rather
+wide; rows of granules, about seven in each compartment, slightly
+radiating.
+
+Blue clay. Not common.
+
+Pl. 10, Fig. 12.
+
+
+PLAGIOGRAMMA TESSELLATUM GREV.
+
+Valve elliptical-lanceolate; central space transversely elliptical to the
+major axis, half the diameter of the valve; terminal spaces more or less
+circular or ovate. Granular markings large, quadrangular, in transverse
+rows. Pseudoraphe not distinct. As the central space does not reach the
+margin, it is a question whether this form is a Plagiogramma or a new
+genus.
+
+Blue clay. Rare.
+
+Pl. 10, Fig. 11.
+
+
+OPEPHORA PETIT (1888)
+
+(ope, an opening, and phoreo)
+
+Frustule rectangular. Valve cuneiform, linear or elliptical-lanceolate,
+with broad, transverse striae and a well-defined pseudoraphe or median
+area.
+
+The genus "portant des stries en forme de boutonnieres," as Petit remarks,
+is quite near Fragilaria, under which the species here described were
+originally included. (See Schmidt's Atlas, Pl. 298, where numerous forms of
+F. pinnata are figured.)
+
+
+OPEPHORA SCHWARTZII (GRUN.) PETIT
+
+Valve obovate-lanceolate or nearly linear with rounded apices; striae
+transverse, broad, 3 or 4 in 10 [mu]; median area lanceolate.
+
+An inner stratum, with puncta in transverse rows, is apparent.
+
+Blue clay. Not uncommon. Variable in size.
+
+Pl. 10, Figs. 16 and 19.
+
+
+OPEPHORA PACIFICA (GRUN.) PETIT
+
+Valve linear, oblong, with rounded apices. Median area linear, narrow;
+striae punctate.
+
+Blue clay.
+
+Pl. 10, Fig. 18.
+
+Petit (Diat. Cap Horn) in his diagnosis states that the valves are
+cuneiform, but they are not always so.
+
+
+{44}OPEPHORA PINNATA VAR. LANCEOLATA N. VAR.
+
+Valve lanceolate; costae slightly radiate, punctate; median area broad,
+lanceolate.
+
+Differs from O. pinnata in outline, radiation of the costae and median
+area.
+
+Blue clay. Rare.
+
+Pl. 10, Fig. 17.
+
+
+
+FRAGILARIINAE
+
+_Fragilaria._--Frustules in fasciae. Valve with transverse striae.
+Pseudoraphe indistinct.
+
+_Rhaphoneis._--Striae radiate; pseudoraphe distinct.
+
+_Dimerogramma._--Pseudoraphe broad.
+
+_Trachysphenia._--Valve cuneiform.
+
+_Synedra._--Valve elongate.
+
+_Asterionella._--Frustules in star-shaped clusters.
+
+
+FRAGILARIA (LYNG.) RAB.
+
+(fragilis, because of the fasciae easily breaking up)
+
+Frustules rectangular, adnate in fasciae, soon breaking up. Valve
+lanceolate, oblong or elliptical in general outline, with convex or sinuate
+margins; without costae; pseudoraphe narrow or indistinct; striae
+transverse. Chromatophores vary according to species. In some they consist
+of four bands on the valves; in others they are granular (Mereschkowsky).
+
+Brun divides the genus into two sections, Fragilaria proper and Staurosira.
+The former, with an indistinct pseudoraphe, includes the species virescens,
+arctica, undata and linearis, while the latter, with distinct pseudoraphe,
+includes capucina, harrisonii, construens and parasitica.
+
+
+FRAGILARIA VIRESCENS RALFS
+
+Frustules in long fasciae. Valve elliptical-lanceolate, obtuse at the
+apices; pseudoraphe indistinct; striae, 17 in 10 [mu], punctate.
+
+Very common in springs and pure streams. The fasciae are often a foot or
+more in length.
+
+Pl. 10, Figs. 20 and 21.
+
+
+FRAGILARIA ARCTICA GRUN.
+
+Valve oblong or elliptical, 10 [mu] in length; striae subtle, with coarse,
+short striae at intervals on the margin and evident in zone view.
+
+Marine. Common at Cape May, N. J.
+
+Pl. 10, Figs. 22 and 23.
+
+
+FRAGILARIA UNDATA WM. SM.
+
+Valve in general outline linear-elliptical, with extremities produced;
+striae subtle; pseudoraphe distinct.
+
+Fresh water.
+
+Pl. 10, Figs. 24, 25, 27, 28 and 29.
+
+
+{45}FRAGILARIA LINEARIS CSTR.
+
+Valve linear, with rounded apices; striae subtle; pseudoraphe indistinct.
+
+Marine. Cape May.
+
+Pl. 10, Fig. 37. Fig. 36 is an indeterminate form occasionally found in the
+blue clay.
+
+
+FRAGILARIA CAPUCINA VAR. MESOLEPTA RAB.
+
+Valve linear, constricted at the hyaline middle; apices slightly produced;
+striae, 17 in 10 [mu]. Quite variable in size.
+
+Schuylkill River. Morrisville (Keeley).
+
+Pl. 10, Fig. 34.
+
+
+FRAGILARIA HARRISONII (WM. SM.) GRUN.
+
+Frustules rectangular, solitary or in twos. Valve cruciform; pseudoraphe
+narrow, lanceolate; striae robust, radiating in the middle, composed of
+confluent puncta, larger at the circumference.
+
+Blue clay.
+
+Pl. 10, Fig. 31.
+
+
+FRAGILARIA CONSTRUENS (EHR.) GRUN.
+
+Valve in general outline lanceolate, with produced apices; pseudoraphe
+lanceolate, distinct or broad; striae subtle, 15 in 10 [mu]. L. of valve,
+10-45 [mu].
+
+_Staurosira construens_ Ehr.
+
+_Odontidium tabellaria_ Wm. Sm.
+
+Blue clay.
+
+Pl. 10, Fig. 30.
+
+
+FRAGILARIA PARASITICA (WM. SM.)
+
+Frustules solitary or in twos. Valve lanceolate, sometimes constricted in
+the middle; pseudoraphe wide, lanceolate; striae subtle. Parasitic on other
+diatoms.
+
+_Odontidium parasiticum_ Wm. Sm.
+
+Not common. Media (Palmer).
+
+In the constricted form it is known as F. construens var. binodis (Ehr.)
+Grun.
+
+Pl. 10, Fig. 35.
+
+An examination of the synonymy of the species of Fragilaria will convince
+the student of the difficulty of determining the correct name even in
+well-known forms. If all of the species of Fragilaria proper have granular
+chromatophores, and all of Staurosira are placcochromatic, a satisfactory
+division can be made, but so long as these facts are not known in all
+species, and as authors have repeatedly confused the two divisions, the
+nomenclature will be uncertain. F. harrisonii is probably in any case to be
+separated from the others. De Toni includes it under its original name of
+Odontidium, which genus he places near to Diatoma. The number of species in
+our locality is too limited to render further discussion of any value.
+
+
+{46}RHAPHONEIS EHR. (1844)
+
+(rhaphis, a needle)
+
+Frustule in zone view linear. Valve lanceolate or elliptical-lanceolate;
+pseudoraphe distinct; striae radiating, moniliform.
+
+
+RHAPHONEIS AMPHICEROS EHR.
+
+Valve lanceolate, broad, with apices produced; striae in curved lines,
+moniliform, the large granules in longitudinal lines.
+
+Blue clay.
+
+Pl. 10, Fig. 38.
+
+
+RHAPHONEIS AMPHICEROS VAR. RHOMBICA GRUN.
+
+Valve as in type form but shorter, with larger and more remote granules.
+
+Blue clay.
+
+Pl. 10, Figs. 39 and 40.
+
+
+RHAPHONEIS BELGICA VAR. INTERMEDIA GRUN.
+
+Valve lanceolate, rostrate; granules in longitudinal and nearly transverse,
+not radiating, lines.
+
+Absecon, N. J.
+
+Pl. 10, Fig. 41.
+
+
+DIMEROGRAMMA RALFS (1861)
+
+(dis, two, meros, a part, gramma, a letter)
+
+Frustules quadrangular, inflated at the angles, in fasciae. Valve ovate or
+lanceolate; striae moniliform, transverse or slightly radiate; median area
+or pseudoraphe broad, lanceolate.
+
+
+DIMEROGRAMMA MARINUM (GREG.) RALFS
+
+Valve lanceolate or linear and inflated in the middle; striae moniliform,
+transverse or slightly radiate; median area linear or lanceolate, sometimes
+not reaching the smooth extremities; striae, 8 in 10 [mu].
+
+Pl. 12, Figs. 9 and 10.
+
+Fig. 9 differs in its lanceolate outline, in having four puncta on each
+side in a row, and in the striae which are radiate.
+
+
+DIMEROGRAMMA SURIRELLA (EHR.) GRUN.
+
+Valve elliptical-lanceolate, with rounded apices; striae moniliform,
+radiate; pseudoraphe narrow, lanceolate.
+
+Blue clay.
+
+Pl. 12, Fig. 11.
+
+
+{47}DIMEROGRAMMA MINUS (GREG.) RALFS
+
+Valve rhombic-lanceolate; striae punctate, radiate; pseudoraphe lanceolate;
+apices smooth.
+
+Blue clay. Along the coast.
+
+Pl. 12, Figs. 12, 13, 14.
+
+
+TRACHYSPHENIA PETIT (1877)
+
+(trachys, rough, and sphen, a wedge)
+
+Frustules rectangular. Valve cuneiform with coarse puncta in transverse and
+longitudinal lines; pseudoraphe narrow, linear. One species only.
+
+
+TRACHYSPHENIA AUSTRALIS PETIT
+
+Characters of the genus. Valve small; puncta, 6 in 10 [mu]. Allied to
+Dimerogramma.
+
+Shark River, N. J. Rare.
+
+Pl. 12, Fig. 15.
+
+
+SYNEDRA EHR. (1830)
+
+(synedrion, a sitting together)
+
+Frustules adnate in small stipitate clusters or free. Valve elongate,
+linear or linear-lanceolate; pseudoraphe distinct; costae absent.
+
+The genus Synedra has few distinctive characters. As Brun remarks (Diat.
+des Alpes et du Jura, p. 122), the dilatation of the extremities and the
+pseudo-nodule are of little value in classification, as the intermediate
+forms are so numerous. Fragilaria occurs in very long ribbons or fasciae,
+Synedra in short fasciae or radiating clusters. Fragilaria is seldom longer
+than three or four times the width, while Synedra is nearly always so. The
+former has fine, often subtle, markings and narrow pseudoraphe, while the
+latter has coarser punctate striae and a more distinct pseudoraphe.
+
+Chromatophores usually consist of two bands, one on each of the valves.
+Karsten states that in the marine forms the chromatophores are oval or
+polygonal discs, each of which usually encloses a pyrenoid.
+
+
+SYNEDRA ULNA (NITZSCH) EHR.
+
+Frustules solitary or in twos. Valve 150-250 [mu] in length, linear or
+linear-lanceolate, with rostrate apices; striae, 9 in 10 [mu].
+
+Common in rivers and streams.
+
+Pl. 11, Figs. 4, 7 and 11 (?).
+
+Frequently interrupted in the middle. The distinction made by Wm. Smith as
+to the presence or absence of the central blank space is probably not
+necessary, as both forms are found which are otherwise identical.
+
+Fig. 5 represents the formation of a sporangial frustule which differs from
+the usual form in its inflated ends prolonged into rostrate apices. Figs. 1
+and 6 are sporangial frustules.
+
+
+{48}SYNEDRA BICEPS (KUETZ.) SCHMIDT
+
+Valve sublanceolate, inflated at the ends, apices rounded; central space
+not always distinct; pseudoraphe narrow; striae radiate at the ends.
+
+This is not Kuetzing's species, if the descriptions and figures are
+accepted, nor is it H. L. Smith's Type No. 545, which is S. ulna var.
+danica, nor is it S. biceps Wm. Smith, but it is exactly Schmidt's form
+(Atlas, Pl. 303, Figs. 10-15).
+
+Schuylkill River.
+
+Pl. 11, Fig. 3.
+
+
+SYNEDRA DANICA KUETZ.
+
+Valve lanceolate, suddenly constricted at the rounded apices; central space
+frequently absent.
+
+Very common in streams.
+
+Pl. 11, Fig. 2.
+
+The figure represents an unusually large form. It differs from S. ulna only
+in its apices.
+
+
+SYNEDRA CAPITATA EHR.
+
+Valve long, linear, dilated into triangular acute apices; pseudoraphe
+distinct; striae radiate at the ends.
+
+Blue clay.
+
+Pl. 11, Fig. 8.
+
+
+SYNEDRA ACUS KUETZ.
+
+Valve very narrow, lanceolate, acicular, with obtuse apices.
+
+Common in the Schuylkill River.
+
+Pl. 11, Figs. 9 and 18.
+
+
+SYNEDRA GOULARDI BREB.
+
+Valve constricted in the middle; apices sub-acute, sometimes slightly
+rostrate or capitate; central space evident.
+
+Neshaminy Creek (Palmer). Blue clay. Crum Creek.
+
+Pl. 11, Figs. 12 and 13.
+
+
+SYNEDRA PULCHELLA (RALFS) KUETZ.
+
+Valve lanceolate, tapering to the sub-acute, rostrate or slightly capitate
+apices; dilated at the central hyaline space; pseudoraphe distinct. Very
+variable in size.
+
+Crum Creek. Schuylkill River. Rather common.
+
+Pl. 11, Figs. 14, 15, 16.
+
+
+SYNEDRA PULCHELLA VAR. ABNORMIS MACCHIATI?
+
+Valve as in type form, except that one end is curved like a beak, as in S.
+hamata Wm. Sm., which it resembles.
+
+Not uncommon in the Schuylkill River.
+
+Pl. 11, Fig. 17.
+
+
+SYNEDRA OXYRHYNCHUS VAR. UNDULATA GRUN.
+
+Valve linear-lanceolate with produced rostrate apices, asymmetrical,
+sigmoid; pseudoraphe narrow; pseudo-nodule large.
+
+Common in fresh water.
+
+Pl. 12, Fig. 1.
+
+
+{49}SYNEDRA PULCHELLA VAR. FLEXELLA N. VAR.
+
+Frustule slightly attenuated at the ends, truncate, somewhat tumid in the
+middle and flexed. Valve lanceolate, with obtuse or subcapitate apices and
+with two almost imperceptible constrictions at the middle producing a tumid
+appearance; pseudoraphe distinct; pseudo-nodule absent. L. 56 [mu]; striae,
+14-16 in 10 [mu].
+
+Some valves are bent and incised on one side. The outline of the valve is
+that of pulchella.
+
+Common at Newtown Square.
+
+Pl. 12, Fig. 2.
+
+
+SYNEDRA RADIANS KUETZ.
+
+Frustules linear, in small fasciae. Valve 34 [mu] in length, linear, with
+apices rostrate, obtuse, sometimes slightly capitate; pseudoraphe distinct;
+striae about 20 in 10 [mu].
+
+Fresh water.
+
+Pl. 10, Figs. 32 and 33.
+
+There is difficulty in recognizing S. radians K. as described and figured
+by different authors. On Plate 12, Fig. 8, I have drawn a specimen from H.
+L. Smith's Type Slide No. 574, labelled S. radians Kuetz., not Wm. Smith,
+which, however, corresponds closely to Smith's figure (Brit. Diat. 1, Pl.
+11, Fig. 89). De Toni gives S. radians Kuetz. as equivalent to S. tenera
+Wm. Sm. Van Heurck's figure of S. radians, and also the figure of ulna
+var., said to be synonymous with H. L. Smith's S. radians, which does not
+correspond to the specimens on Smith's slide in my possession, are
+confusing. In Van Heurck's Synopsis the striae are said to be 16 or 17,
+while De Toni describes them as subtle and from 17 to 24 in 10 [mu]. The
+length is quite variable.
+
+Several species of Synedra resemble S. radians in the mode of growth, as
+they are adnate at first, in short bands, the frustules being sessile on
+other plants or objects, attached at the terminal nodules which, although
+scarcely visible in most forms, are probably present in all. The frustules
+are not closely connected at the free end, and soon become entirely
+detached.
+
+In Diatoma and Fragilaria, we find a punctum or pore at one end of a valve,
+but not in line with the pseudoraphe; in Synedra, a minute pore is usually
+found in the position of the terminal nodule and, in some species,
+indications of a central nodule are observed; the median line is wider but
+there is no raphe. In the fresh-water Synedrae, many of which are among the
+longest of diatoms, living in running streams, the terminal nodules are
+much more indistinct, while the marine forms have distinct terminal
+nodules, are not, as a rule, found in bands, and assume a more naviculoid
+outline.
+
+
+SYNEDRA VAUCHERIAE VAR. PARVULA (KUETZ.) RAB.
+
+Valve lanceolate, with produced or rostrate apices; pseudo-nodule wide,
+excentric. L. 17 [mu].
+
+Crum Creek.
+
+Pl. 12, Fig. 5.
+
+Fig. 6 represents a variety with coarser striae from the Schuylkill River.
+Both are easily mistaken for Fragilaria intermedia.
+
+
+{50}SYNEDRA FULGENS (GREV.) WM. SM.
+
+Frustules geminate or flabellate on a stipe. Valve slightly inflated in the
+middle and at the apices; pseudoraphe narrow; striae finely punctate,
+radiate at the ends.
+
+Marine. Atlantic City.
+
+Pl. 11, Fig. 10.
+
+
+SYNEDRA AFFINIS KUETZ.
+
+Valve lanceolate; striae marginal, leaving a broad lanceolate pseudoraphe.
+
+Common along the coast.
+
+Pl. 12, Fig. 3.
+
+
+SYNEDRA AFFINIS VAR. PARVA (KUETZ.) V. H.
+
+Valve lanceolate, slender; striae marginal, shorter than in the type.
+
+_Synedra gracilis_ Kuetz.
+
+Common along the coast.
+
+Pl. 12, Fig. 7.
+
+
+SYNEDRA AFFINIS VAR. TABULATA (AG.) V. H.
+
+Valve linear-lanceolate; striae, 11 in 10 [mu], very short.
+
+Not common. New Rochelle.
+
+Pl. 12, Fig. 4.
+
+
+ASTERIONELLA HASSALL (1855)
+
+(dim. of aster, a star)
+
+Frustules linear, slightly inflated at the ends, arranged in star-shaped
+clusters which soon break up. Valve linear, unequally inflated at the ends.
+
+
+ASTERIONELLA FORMOSA HASS.
+
+Valve clavate at the ends; striae transverse, 17 in 10 [mu], pseudoraphe
+very narrow or indistinct; an ovoid, hyaline area at each end.
+
+Newark, N. J. Broomall's Lake, Media (Palmer).
+
+Pl. 12, Figs. 19, 20, 21.
+
+
+ASTERIONELLA INFLATA HEIB.
+
+Valve linear, capitate at each end and tumid in the middle; striae
+distinctly punctate; pseudoraphe indistinct, or not apparent. L. 30 [mu].
+
+Fresh water. May's Landing, N. J.
+
+Pl. 12, Fig. 22.
+
+
+
+EUNOTIINAE
+
+_Eunotia._--Frustules either free, in fasciae or epiphytic. Valves arcuate.
+
+_Actinella._--Frustules, solitary or in small clusters, cuneate. Valve
+inflated at one end.
+
+
+{51}EUNOTIA EHR. (1837) em. GRUN. (1862)
+
+(eu, well, and noton, a back, referring to the strong, ridged dorsum)
+
+Frustules free, in fasciae or epiphytic. Valve arcuate, without costae,
+transversely striated; pseudoraphe absent; pseudo-nodules at each end.
+
+Chromatophores laminate along the concave zone and the valves.
+
+Very many species of Eunotia have been created to differentiate size and
+number of crenae or undulations. An examination of certain fossil deposits
+of New England, as well as a gathering from the blue clay of Philadelphia,
+will show forms which vary infinitely. E. major and E. gracilis are
+scarcely distinguishable because of the intermediate variations. The striae
+in all forms are punctate, but the puncta are frequently confluent.
+
+
+ANALYSIS OF SPECIES
+
+Eunotia is divided into two sections, Himantidium and Eunotia proper. In
+Himantidium, the frustules are in fasciae, either short or long. Among
+those with short fasciae are major, gracilis, and nymanniana; those with
+long fasciae are pectinalis, solierolii and veneris. Eunotia proper
+includes frustules, free or epiphytic, in which the valves are not dentate
+on the dorsal margin, such as lunaris, hemicyclus, biceps and praerupta;
+and those in which the valves are dentate or crenate on the dorsum, such as
+monodon, triodon, diadema and others.
+
+The resemblance between Eunotia and Epithemia is noticeable. In both, the
+epiphytic character of the valve is seen in the shape of the frustule which
+is arched, and, in the free forms, is adherent at the ends only. In
+Epithemia, the median is more evident than the terminal nodules. In
+Eunotia, there is no median nodule, but the end nodules, in some species,
+are quite evident, and a tendency is shown to produce a very short raphe.
+The arrangement of puncta in valve view is similar in both genera.
+
+
+SECTION 1. HIMANTIDIUM
+
+EUNOTIA MAJOR (WM. SM.) RAB.
+
+Valve arcuate, linear, subcapitate, recurved. Striae punctate, 12 in 10
+[mu] L. 90-190 [mu].
+
+Common in fresh water.
+
+Pl. 13, Figs. 1 and 2.
+
+
+EUNOTIA GRACILIS (EHR.) RAB.
+
+Valve with sides parallel; apices slightly capitate and revolute; striae,
+10 in 10 [mu]. The striae on the connective membrane more delicate than in
+E. major. Intermediate forms occur.
+
+Common in fresh water.
+
+Pl. 13, Fig. 3. Fig. 4 is indeterminate.
+
+
+EUNOTIA NYMANNIANA GRUN.
+
+Valve small, curved, with parallel dorsal and ventral margins; apices
+truncate and recurved into dorsal elevations; striae delicate.
+
+Blue clay. Not common.
+
+Pl. 13, Fig. 32.
+
+
+{52}EUNOTIA PECTINALIS (KUETZ.)
+
+Valve linear, arcuate, apices slightly rostrate; striae distinctly punctate
+with puncta in longitudinal rows nearer together at the ends.
+
+_Himantidium pectinale_ Kuetz.
+
+Common in fresh water.
+
+Pl. 13, Figs. 6 and 7.
+
+The fasciae are associated in large masses, sometimes an inch or more in
+diameter, and late in August are found a foot or more in length, of a
+beautiful chocolate color. Exceedingly abundant in the cedar-swamp streams
+of the Pine Barren regions of New Jersey. In winter, the dead frustules
+form a parchment-like coating upon the twigs, dead leaves, and other debris
+on the borders of streams.
+
+This species can scarcely be referred to Dillwyn's Conferva pectinalis, as,
+in his description, quoting Mueller, he says that "the filaments are of a
+dirty green color; seldom exceeding half an inch in length." Dillwyn's form
+is probably Fragilaria virescens, which equals Fragilaria pectinalis Ehr.,
+while Kuetzing's species is Fragilaria pectinalis Ralfs. It is not
+impossible to confuse Fragilaria virescens and Eunotia pectinalis when the
+zone only is seen under a low power and their mode of growth is similar.
+
+
+EUNOTIA PECTINALIS VAR. UNDULATA RALFS
+
+Valve as in type form, but with undulate margins.
+
+Common in the cedar swamps of New Jersey.
+
+Pl. 13, Figs. 8 and 10.
+
+
+EUNOTIA PECTINALIS VAR. SOLIEROLII (KUETZ.)
+
+Valve as in type, but with internal divisions as though in the process of
+reduplication.
+
+Not common. Moorestown, N. J. (Palmer).
+
+Pl. 13, Fig. 9.
+
+
+EUNOTIA PECTINALIS VAR. VENTRICOSA GRUN.
+
+As in type, but with the valves tumid in the middle.
+
+May's Landing, N. J.
+
+Pl. 13, Fig. 12.
+
+Fig. 11 is a form found in the blue clay. It differs in the coarser puncta
+from the var. ventricosa. In outline it resembles Eunotia arcus Wm. Sm.,
+which is Ceratoneis arcus (Ehr.) Kuetz., but the central nodule is not
+present as in the latter form, which connects Eunotia and Cymbella. It may
+be a form of E. luna Ehr. (A. S., Atlas, Pl. 286, Figs. 33 and 34.)
+
+
+EUNOTIA VENERIS KUETZ.
+
+Valve with convex dorsal and straight ventral margins, more or less
+constricted near the sub-acute apices. Striae subtle, punctate.
+
+_Eunotia incisa_ Greg.
+
+May's Landing, N. J. Blue clay, Pavonia, N. J.
+
+Pl. 13, Figs. 30 and 31.
+
+
+{53}EUNOTIA (PROPER)
+
+EUNOTIA LUNARIS (EHR.) GRUN.
+
+Frustules sessile, solitary or in clusters. Valve arcuate, narrow,
+attenuated toward the apices, which are sometimes slightly rostrate or
+rostrate-capitate; transverse striae, 14 in 10 [mu], punctate.
+
+Very common in ditches, especially in the spring. Variable in length.
+
+Pl. 12, Figs. 24 and 25.
+
+
+EUNOTIA HEMICYCLUS (EHR.) RALFS
+
+Valve semicircular, with obtuse apices; striae transverse, punctate;
+terminal nodules minute and indistinct.
+
+Hammonton Pond, N. J. Rare.
+
+Pl. 12, Fig. 23.
+
+The genus Pseudo-Eunotia was created by Grunow for forms like Eunotia, but
+without terminal nodules. As, however, in E. lunaris and E. hemicyclus
+nodules are evident, although not so large as in many species, I include
+these two forms as heretofore under Eunotia.
+
+
+EUNOTIA BICEPS EHR.
+
+Valve linear, slightly arcuate, narrow, with rounded apices somewhat
+revolute; striae, 16 in 10 [mu].
+
+May's Landing, N. J.
+
+Pl. 13, Fig. 27.
+
+
+EUNOTIA PRAERUPTA EHR.
+
+Valve convex on dorsal side, apices dilated and truncate; striae distant at
+centre.
+
+Common in the blue clay.
+
+Pl. 13, Fig. 5.
+
+
+EUNOTIA PRAERUPTA VAR. BIDENS GRUN.
+
+Valve with two undulations; otherwise as in type.
+
+_Eunotia bigibba_ Greg.
+
+With the type.
+
+Pl. 13, Fig. 19.
+
+
+EUNOTIA ROBUSTA RALFS
+
+Valve arcuate, with several or numerous dorsal ridges or crenae which
+decrease in relative size in proportion to their number. Striae radiate,
+variable in distance apart, and in size of puncta.
+
+Ralfs included under this one name the following species named by
+Ehrenberg: E. diodon (2 crenae); E. triodon (3); E. tetraodon (4); E.
+pentodon (5); E. diadema (6); E. heptodon (7); E. octodon (8); E. enneadon
+(9); E. decadon (10); E. hendecadon (11); E. duodecadon (12); E. serra
+(13); E. prioritis (14); all more than 20, E. polyodon. E. scalaris, with
+from 15 to 17 crenae, and E. icosodon with 20, may be added.
+
+It is probable that all of these forms occur at May's Landing, N. J. The
+forms with more than eight crenae are comparatively rare. In the blue clay
+those with from four to six are most common.
+
+Pl. 13, Figs. 13, 14, 15, 16, 17, 21, 24, 25.
+
+
+{54}EUNOTIA BACTRIANA EHR.
+
+Valve linear, apices revolute, acute, dentate on the dorsal margin, with
+one acute crena near each end.
+
+Tom's River, N. J. Rare.
+
+Pl. 13, Fig. 18.
+
+
+EUNOTIA BIDENTULA WM. SM.
+
+Valve with straight ventral margin, and with two undulations on the dorsum;
+apices large, rounded.
+
+May's Landing, N. J. Rare.
+
+Pl. 13, Fig. 20 (not Schumann's form, which has angular crenae).
+
+
+EUNOTIA FORMICA EHR. VAR.?
+
+Valve turgid in the middle and at the apices which are unilaterally
+truncate.
+
+Pensauken, N. J. (artesian well).
+
+Pl. 13, Fig. 26 (not a typical form).
+
+The following are forms which appear to be indeterminate, or, in any case,
+are scarcely worthy of distinction by specific names, as might be said of
+others of the innumerable variations of this genus:
+
+Fig. 23, Pl. 13, probably a form of praerupta. Newtown Square.
+
+Fig. 28, Pl. 13, from the blue clay.
+
+Fig. 29, Pl. 13, an asymmetrical form, apparently abnormal, but not rare at
+May's Landing, N. J.
+
+Fig. 17, Pl. 38. Valve convex on the dorsal side, incised on the ventral;
+striae about 15 in 10 [mu], closer at the ends; L. 30 [mu]. Schuylkill
+River.
+
+Fig. 18, Pl. 38. Valve arcuate, asymmetrical, broader at one end; terminal
+nodules large; striae, 10 in 10 [mu]; L. 47 [mu]. Gloucester, N. J.,
+artesian well.
+
+Numerous variations of the above species are illustrated in Schmidt (Atlas,
+Pls. 285-291).
+
+
+ACTINELLA LEWIS (1865)
+
+(dim. of actin, a ray)
+
+Frustules solitary, or in small clusters, sub-cuneate or nearly linear.
+Valve arcuate, rounded at one end and suddenly widened at the other into a
+cup-shaped or lychnoid inflation.
+
+
+ACTINELLA PUNCTATA LEWIS
+
+Valve with fine, transverse striae; on the margin, puncta at intervals;
+terminal nodules distinct.
+
+May's Landing, N. J.
+
+Pl. 12, Figs. 16, 17, 18.
+
+Fig. 17, from Tom's River, N. J., is an approach toward A. brasiliensis
+Grun.
+
+Fig. 18 represents the frustules geminate, a frequent occurrence.
+
+
+
+{55}NAVICULOIDEAE
+
+In discussing the Naviculoid group, the general divisions of Cleve are here
+followed, and all diatoms having a true raphe are included. I have added
+the genus Epithemia and also Rhopalodia, partly because they contain a
+raphe of a certain kind and partly because they resemble the markings of
+certain of the genus Hantzschia in the following group, although in other
+respects there is probably no similarity.
+
+The difficulty of combining the numerous genera into groups which are
+naturally affiliated is avoided in the following arrangement based on
+superficial similarities, and is intended merely as an artificial key. To
+unite all forms having a raphe and which are symmetrical with valves
+similar and not sigmoid, under the one genus Navicula, as has been the
+custom previous to the publication of Cleve's monograph, would result in
+associating species differing in so many respects in relation to structure
+of the valve and cell contents that it seems advisable to retain the new
+genera, especially as the original genus is likely to be still further
+reduced when more is known of the structure and life history of the group.
+
+
+KEY TO THE GENERA
+
+
+  Valves dissimilar. Achnantheae
+
+  symmetrical                                                 Cocconeis
+
+  asymmetrical
+
+    to the longitudinal axis                                  Anorthoneis
+
+    to the transverse axis                                    Rhoicosphenia
+
+    in zone view                                              Achnanthes
+
+  Valves similar and asymmetrical
+
+  asymmetrical to the longitudinal axis
+
+    valves parallel                                           Cymbella
+
+    valves not parallel                                       Amphora
+
+    valves keeled, twisted (sometimes symmetrical)            Amphiprora
+
+    valves keeled                                             Tropidoneis
+
+    valves reniform and keeled                                Auricula
+
+    median line sigmoid at the ends                           Scoliotropis
+
+  asymmetrical to the transverse axis
+
+    striae punctate and costate                               Gomphoneis
+
+    striae punctate                                           Gomphonema
+
+  Valves similar, symmetrical and sigmoid
+
+    striae oblique                                            Pleurosigma
+
+    striae at right angles                                    Gyrosigma
+
+  Valves similar, symmetrical, not sigmoid
+
+    striae punctate, nodules elongated                        Frustulia
+
+    striae subtly punctate, central nodule forked             Amphipleura
+
+    striae punctate and reticulate, in two strata             Dictyoneis
+
+    striae punctate and alveolate, in three strata            Trachyneis
+
+    striae punctate, in two strata                            Brebissonia
+
+    striae interrupted by blank lines                         Anomoeoneis
+
+    striae crossed by longitudinal lines                      Caloneis
+
+    striae oblique, median fissures in opposite directions    Neidium
+
+    striae punctate and costate, median line with horns       Diploneis
+
+    striae punctate; valves separated by septate plates       Mastogloia
+
+    striae punctate, central area dilated into a stauros      Stauroneis
+
+    striae punctate, area without stauros or horns            Navicula
+
+    striae costate, not punctate                              Pinnularia
+
+
+
+{56}ACHNANTHEAE
+
+Frustules stipitate, free or parasitic. Valves cuneate, elliptical or
+suborbicular, dissimilar, bent along the transverse or the longitudinal
+axes, the lower valve with a true raphe and central and terminal nodules,
+the upper valve with a pseudoraphe or median line.
+
+_Rhoicosphenia._--Stipitate; valves with transverse puncta, bent along the
+transverse axis, cuneate, with diaphragms at the ends.
+
+_Anorthoneis._--Free; puncta radiate; valves bent slightly along the
+transverse axis, suborbicular.
+
+_Cocconeis._--Parasitic; valves elliptical, usually bent along the
+longitudinal axis; striae punctate, transverse and longitudinal.
+
+_Achnanthes._--Stipitate; valves lanceolate or elliptical, bent along the
+transverse axis; striae transverse, punctate; costae sometimes present.
+
+
+RHOICOSPHENIA GRUN. (1860)
+
+(rhoicos, curved, and sphen, a wedge)
+
+Frustule in zone view curved; valves cuneate, dissimilar, the upper with a
+pseudoraphe, the lower with a raphe.
+
+Chromatophore a single plate along both valves, and one of the inner walls
+of the zone. Conjugation as in Gomphonema, with which it is generally
+associated in classification.
+
+
+RHOICOSPHENIA CURVATA (KUETZ.) GRUN.
+
+Valve clavate, with rounded apex and base; lower valve with raphe, a narrow
+axial area and slightly radiate, punctate striae; the upper valve with a
+narrow pseudoraphe and parallel striae; a short diaphragm at the ends of
+each valve. Length usually from 15 to 25 [mu], but frequently of twice the
+size.
+
+Common in Crum Creek.
+
+Pl. 19, Figs. 25, 26, 27.
+
+
+ANORTHONEIS GRUN. (1868)
+
+(anorthos, not straight)
+
+Valves dissimilar, the upper valve with an excentric axial area, the lower
+with an excentric raphe.
+
+
+ANORTHONEIS EXCENTRICA (DONK.) GRUN.
+
+Valves orbicular, with radiating, punctate striae, closer at the
+circumference, producing the appearance of a border. Axial area not
+reaching the ends. Frustules occur free on the sands of the sea-shore. L.
+25 to 50 [mu].
+
+Belmar, N. J.
+
+Pl. 16, Figs. 30 and 31.
+
+
+{57}COCCONEIS EHR. (1835) em. GRUN. (1868)
+
+(coccos, a berry)
+
+Valves elliptical, dissimilar, the upper valve with a pseudoraphe and the
+lower with a genuine raphe and nodules, usually with a rim or annulus.
+Frustules epiphytic.
+
+Cocconeis is generally considered as a degenerated form of Mastogloia, as
+indicated by the "obsoletely loculiferous rim." The frustules are usually
+bent along the longitudinal axis, probably because of the attachment to the
+curved stems of water-plants.
+
+The cell contents of only a few species are known. In C. pediculus, a
+single chromatophore occurs on the inside of the upper valve. In
+conjugation, two cells open and secrete a gelatinous mass from which an
+auxospore is formed.
+
+Cleve separates the forms having a loculiferous rim (Cocconeis) from those
+without a rim (Eucocconeis). As the rim is easily detachable, the
+distinction is often made with difficulty.
+
+
+COCCONEIS SCUTELLUM EHR.
+
+Valves elliptical, the upper with a linear or lanceolate pseudoraphe and
+coarse puncta in transverse and radiating lines; the lower valve with much
+finer puncta in radiating lines, a lanceolate axial area and, sometimes, a
+loculiferous rim.
+
+Along the coast. Common, but extremely variable.
+
+Pl. 16, Fig. 21 (upper valve). Fig. 18, var. ?
+
+
+COCCONEIS SCUTELLUM VAR. ORNATA GRUN.
+
+Upper valve with linear axial area, and transverse and radiating punctate
+lines which end at the border in a double row of finer puncta; lower valve
+with much finer puncta, a lanceolate axial area and a loculiferous rim.
+
+Atlantic City. Common.
+
+Pl. 16, Figs. 27 and 28.
+
+The forms along the coast vary infinitely both in size and appearance. The
+var. ornata is very abundant along the entire coast. In any gathering,
+valves are found with or without the rim which is frequently seen detached.
+The upper valve is sometimes without the double row of puncta. Fig. 21
+represents an upper valve more coarsely punctate than usually occurs. Very
+many intermediate forms might be noticed.
+
+
+COCCONEIS PEDICULUS EHR.
+
+Valves rhombic-elliptical, very convex, somewhat asymmetrical; the upper
+valve with a linear pseudoraphe, sometimes widened near the ends, and
+slightly radiating, finely punctate striae; lower valve with narrow, axial
+area and finely punctate, radiating striae.
+
+Not uncommon in fresh water. Abundant in a ditch at Paoli, Pa.
+
+Pl. 16, Figs. 23 and 24.
+
+
+COCCONEIS PLACENTULA EHR.
+
+Valve elliptical; upper valve with a linear or lanceolate axial area, and
+punctate striae in transverse and radiating rows, the puncta at equal
+distances; the lower valve with a lanceolate axial area, radiating rows of
+puncta, and a wide border of finely punctate, radiating striae, separated
+from the central part of the valve by a narrow hyaline zone.
+
+Common in salt, brackish and fresh water.
+
+Pl. 16, Figs. 19 and 20.
+
+
+{58}COCCONEIS PLACENTULA VAR. LINEATA (EHR.) V. H.
+
+As in the type, except that the upper valve has the puncta arranged in
+zig-zag, giving the appearance of sinuous, longitudinal lines.
+
+Common along the coast.
+
+Pl. 16, Fig. 29.
+
+C. pediculus and C. placentula are the only species I have found in fresh
+water. Cleve states that the former occurs also in brackish water.
+
+The following are among the species placed by Cleve in a new genus,
+Eucocconeis, distinguished by the absence of a loculiferous rim.
+
+
+COCCONEIS DIRUPTA GREG.
+
+Valves elliptical, the lower with fine puncta in slightly radiating lines,
+a narrow axial area and a central area dilated into a lanceolate,
+stauriform space; the terminal fissures turned in opposite directions; the
+upper valve similar to the lower valve except in the absence of raphe and
+nodules.
+
+Along the coast. New Rochelle.
+
+Pl. 16, Fig. 22 (lower valve).
+
+
+COCCONEIS PELLUCIDA GRUN.
+
+Valves elliptical, the upper with broad axial area on each side of which
+are fine, longitudinal rows of short striae; the lower valve with more
+numerous longitudinal rows, a marginal line and indistinct raphe; the
+terminal fissures small and turned in opposite directions.
+
+New Rochelle.
+
+Pl. 16, Figs. 25 and 26.
+
+In the var. minor Grun. the median line of the lower valve is sometimes
+slightly sigmoid.
+
+
+ACHNANTHES BORY (1822)
+
+(achne, froth or down, and anthos, a flower)
+
+Frustules stipitate, solitary or in short fasciae, flexed. Valves
+elliptical or lanceolate, naviculoid, dissimilar, the lower with a raphe
+and median and terminal nodules, and the upper with a pseudoraphe or median
+space.
+
+The genus has no apparent affinity with any other.
+
+
+ACHNANTHES LONGIPES AG.
+
+Valves linear-elliptical, obtuse at the apex, sometimes slightly
+constricted in the middle. Connective zone with transverse, subtly punctate
+striae, interrupted by longitudinal lines. Central nodule of lower valve
+dilated into a stauros reaching the margin. Valves costate, the costae
+alternating with double rows of fine puncta.
+
+Along the coast, in estuaries.
+
+Pl. 16, Figs. 1 and 2.
+
+A. longipes is the only species in our locality considered by Cleve as
+belonging to the genus; the other forms, distinguished by the absence of
+costae, are included in the genus Achnanthidium of Kuetzing.
+
+In A. longipes, the chromatophores consist of scattered, rounded granules,
+while in Achnanthidium the chromatophore is a single plate along the upper
+valve, or a double one {59}along the connective zone. It is necessary,
+therefore, to distinguish between A. longipes and the following group, but,
+because of the long continued union of all of the stipitate forms having
+the general appearance of a true Achnanthes, I shall continue to describe
+the local species under the generally accepted name.
+
+
+ACHNANTHES BREVIPES AG.
+
+Valves without costae; striae moniliform; upper valve with excentric
+pseudoraphe or median line; otherwise as in A. longipes.
+
+Along the coast, in estuaries.
+
+Pl. 16, Fig. 3.
+
+
+ACHNANTHES SUBSESSILIS KUETZ.
+
+Valves linear-elliptical, rounded at the ends; upper valve with excentric
+pseudoraphe; striae moniliform, puncta smaller than in A. brevipes.
+
+Along the coast, in estuaries.
+
+Pl. 16, Figs. 4, 5, 6.
+
+The three species described above are named from the length of the stipe,
+but this varies considerably and is not of special significance.
+
+
+ACHNANTHES INFLATA (KUETZ.) GRUN.
+
+Valves more or less inflated in the middle, usually with the stauros of the
+lower valve asymmetrical and wider than in A. subsessilis, with which it
+agrees in size and markings.
+
+Gloucester, N. J. (artesian well).
+
+Pl. 16, Figs. 7 and 8.
+
+
+ACHNANTHES COARCTATA (BREB.) GRUN.
+
+Valves lanceolate, oblong, broad at the ends and constricted in the middle.
+Stauros wide; pseudoraphe of the upper valve excentric; striae slightly
+radiate on the lower valve; puncta small.
+
+Blue clay.
+
+Pl. 16, Fig. 9.
+
+
+ACHNANTHES LANCEOLATA (BREB.) GRUN.
+
+Valves more or less elliptical; striae radiating, 12 in 10 [mu], punctate;
+on the lower valve a horse-shoe shaped hyaline space on one side of the
+centre; on the upper valve an irregular stauros, not reaching the margin.
+L. 8-20 [mu].
+
+In springs. Abundant at Newtown Square.
+
+Pl. 16, Figs. 10, 11, 12.
+
+
+ACHNANTHES EXIGUA GRUN.
+
+Valves oblong-lanceolate, with rostrate ends, sometimes slightly
+constricted in the middle. Stauros rather wide; striae punctate, radiating,
+22 in 10 [mu]. L. 10-12 [mu].
+
+_Stauroneis exilis_ Kuetz. (not Achnanthes exilis Kuetz.)
+
+Frequently found in aquaria where I have kept it growing continuously for
+years.
+
+Pl. 16, Figs. 14 and 15.
+
+
+ACHNANTHES LINEARIS FORMA CURTA H. L. SMITH
+
+Frustules solitary or geminate. Valves linear-elliptical, or
+elliptical-lanceolate. Lower valve without distinct axial area; upper valve
+with axial area widened in the middle; striae slightly radiate (?). L. 7
+[mu]. One of the smallest of diatoms.
+
+{60}This form I found in a pure gathering covering the sides of a
+greenhouse tank at Elm, N. J. It was sent to Prof. H. L. Smith, who
+determined it as forma curta of A. linearis.
+
+Pl. 16, Figs. 16 and 17.
+
+
+ACHNANTHES DANICA (FLOEGEL) GRUN.
+
+Valves rhombic-lanceolate, with subacute ends. Striae, 25 in 10 [mu],
+radiate. Lower valve with stauros widened toward the margin, and cleft into
+three divisions.
+
+Pavonia, N. J. (artesian well).
+
+Pl. 16, Fig. 13.
+
+I have seen the lower valve only. Cleve states that the upper valve is
+costate with "alternating fine lineolae twice as close as the costae."
+
+
+CYMBELLA AG.  (1830)
+
+(cymbe, a boat)
+
+Frustules free, stipitate or enclosed in tubes. Valve boat-shaped; median
+line asymmetrical, straight or curved.
+
+Chromatophore single, covering the entire interior of the frustule, except
+the ventral part of the zone and the median lines. Its longitudinal axis is
+on the dorsal part of the zone. A pyrenoid lies in a fold of the
+chromatophore on the dorsal part.
+
+The genus includes the former genera of Cocconema, characterized by
+stipitate forms, and Encyonema in which the frustules are frequently
+enclosed in gelatinous tubes.
+
+
+SECTION 1.--CYMBELLA PROPER. FRUSTULES FREE OR SOMETIMES STIPITATE
+
+CYMBELLA HETEROPLEURA (EHR.) KUETZ.
+
+Valve nearly symmetrical, lanceolate, with rostrate, produced apices;
+median line nearly straight; axial area linear, widened in the middle;
+striae radiate, punctate.
+
+Blue clay.
+
+Pl. 18, Fig. 10.
+
+
+CYMBELLA CUSPIDATA KUETZ.
+
+Valve broad, elliptical, with rostrate, somewhat acute, apices and nearly
+straight, ventral margin; median line straight, axial area linear, widened
+in the middle; striae radiate, punctate.
+
+Blue clay.
+
+Pl. 18, Fig. 17.
+
+
+CYMBELLA NAVICULIFORMIS AUERSWALD
+
+Valve linear-elliptical, with abruptly produced apices; ventral margin
+straight; median line almost straight; axial area narrow, central area
+large, rounded; striae distant in the middle, closer at the ends.
+
+Fresh water.
+
+Pl. 18, Fig. 6.
+
+
+CYMBELLA EHRENBERGII KUETZ.
+
+Valve lanceolate, with ventral margin nearly straight and apices
+sub-rostrate; median line straight, excentric; axial area narrow; central
+area widened in the middle; striae coarsely punctate.
+
+Fresh water.
+
+Pl. 18, Fig. 9.
+
+
+{61}CYMBELLA AFFINIS KUETZ.
+
+Valve about three times as long as broad, strongly convex on the dorsal
+side and straight on the ventral; apices sub-rostrate; striae punctate;
+axial area narrow, not widened in the middle; median line curved; a small
+or indistinct punctum on the ventral side of the median line (not shown in
+the figure).
+
+Common in ponds. Abundant in East Park Reservoir.
+
+Pl. 18, Fig. 18.
+
+
+CYMBELLA EXCISA (KUETZ.) DE TONI
+
+Valve as in affinis, but with tumid and excised ventral margin; a punctum
+is found on the ventral side (not shown in the figure).
+
+According to Cleve this is a variety of C. affinis.
+
+Common in ponds.
+
+Pl. 18, Figs. 15, 19?
+
+
+CYMBELLA PARVA (WM. SM.) CL.
+
+Valve semi-lanceolate, with produced apices; ventral margin slightly tumid;
+axial area narrow; striae coarsely but obscurely punctate.
+
+C. affinis and C. parva are quite variable, the latter differing by its
+lanceolate form and the absence of a punctum, which, however, is sometimes
+difficult to recognize. In a gathering of C. parva, it is quite possible to
+find numerous abnormal forms which appear to be sporangial, so that
+specific distinctions are difficult if based on occasional specimens.
+
+Common in ponds.
+
+Pl. 38, Fig. 14.
+
+
+CYMBELLA AMPHICEPHALA NAEGELI
+
+Valve unequally elliptical, with broad, rostrate apices; axial area narrow;
+median line straight; central area small, rounded; striae, 12 in 10 [mu] on
+the dorsal, closer on the ventral, side and at the ends.
+
+Kirkwood Pond, N. J.
+
+Pl. 18, Fig. 16.
+
+
+CYMBELLA SINUATA GREG.
+
+Valve linear-elliptical, gibbous on the ventral side; axial area
+indistinct; central area widened on the ventral side nearly to the margin.
+
+Crum Creek.
+
+Pl. 18, Fig. 13.
+
+
+SECTION 2.--COCCONEMA. FRUSTULES STIPITATE
+
+CYMBELLA ASPERA (EHR.) CL.
+
+Valve large, cymbiform, arcuate on the dorsal, slightly gibbous on the
+ventral side; axial area linear, broad, slightly widened in the middle; no
+row of puncta on the ventral side. The puncta form curved longitudinal
+lines and the innermost row on the ventral side appears sometimes distant
+from the others, but not as in C. cistula.
+
+_Cocconema asperum_ Ehr.
+
+_Cymbella gastroides_ Kuetz.
+
+{62}Not Cymbella gastroides H. L. Smith, Type No. 118, which is C. mexicana
+A. S., having a punctum in the middle of the central nodule; in outline it
+is like C. gastroides var. minor Kuetz.
+
+Blue clay.
+
+Pl. 18, Fig. 1 (an unusual form, but it resembles Grunow's. (Diat. Franz
+Jos. Land, Pl. 1, Fig. 7.)
+
+
+CYMBELLA CYMBIFORMIS (KUETZ.) BREB.
+
+Valve cymbiform, slightly gibbous on the ventral margin; apices broad,
+somewhat truncate; a punctum occurs on the ventral side of the median line;
+striae, 8 in 10 [mu], closely punctate.
+
+Kirkwood Pond, N. J.
+
+Pl. 18, Fig. 2.
+
+
+CYMBELLA CISTULA (HEMPR.) KIRCHN.
+
+Valve cymbiform, with gibbous ventral margin and truncate apices; a
+distinct row of several puncta occurs below the median line in typical
+forms.
+
+Blue clay.
+
+Pl. 18, Fig. 3.
+
+
+CYMBELLA LANCEOLATA (EHR.) KIRCHN.
+
+Valve cymbiform, with gibbous ventral margin; apices truncate; axial area
+very narrow, scarcely widened in the middle; striae with fine close puncta.
+
+Kirkwood Pond, N. J.
+
+Pl. 18, Fig. 4.
+
+
+CYMBELLA MEXICANA (EHR.) A. S.
+
+Valve broad, with gibbous ventral margin and sub-rostrate, truncate apices;
+median line with reflexed terminal fissures; striae with coarse puncta; a
+large punctum occurs in the centre of the central area.
+
+Blue clay.
+
+Pl. 18, Fig. 5.
+
+
+CYMBELLA TUMIDA (BREB.) V. H.
+
+Valve cymbiform, with gibbous ventral margin and abruptly rostrate ends;
+median line arcuate; axial area narrow; central area large, orbicular;
+below the central nodule is a punctum; striae punctate.
+
+Crum Creek.
+
+Pl. 18, Fig. 7.
+
+
+SECTION 3.--ENCYONEMA. FRUSTULES IN TUBES
+
+CYMBELLA VENTRICOSA KUETZ.
+
+Valve lunate, with straight or slightly gibbous ventral margin; axial area
+indistinct; median line straight or nearly so; striae punctate.
+
+Very common, but extremely variable. The ventral margin is sometimes
+straight and sometimes quite gibbous.
+
+Pl. 18, Figs. 14, 22; Pl. 38, Fig. 16; Pl. 40, Fig. 8.
+
+{63}C. ventricosa is considered by some authors to be equivalent to C.
+affinis var. semicircularis Lagerst., Encyonema prostratum (Berk.) Ralfs,
+E. caespitosum Kuetz. and E. auerswaldii Rab. H. L. Smith's Type Slide of
+C. ventricosa Ag. is said to equal C. affinis Kuetz., but the specimens
+appear to me to be equivalent to C. ventricosa Kuetz. Cleve unites many
+forms, including E. caespitosum, under C. ventricosa.
+
+
+CYMBELLA PROSTRATA (BERK.) CL.
+
+Valve semi-elliptical, obtuse at the apices, which are sometimes prolonged
+and turned downwards; median line straight, terminal nodules distant from
+the ends; axial area narrow, central area rounded; striae in radiating,
+slightly curved lines, indistinctly punctate.
+
+Common in fresh water; occasional in brackish.
+
+Pl. 18, Fig. 21 (represents a frequent variation).
+
+
+CYMBELLA PHILADELPHICA N. SP.
+
+Valve semi-elliptical-lanceolate, with rounded apices; ventral margin
+strongly gibbous; terminal nodules distant from the ends; axial area broad,
+central area widened on the dorsal side; striae radiate, not curved nor of
+unequal length, indistinctly punctate, 10 in 10 [mu] on the dorsal, 8 in 10
+[mu] on the ventral side. L. 86 [mu].
+
+This form approaches Encyonema prostratum (Berk.) Ralfs, Schmidt's Atlas,
+Pl. 71, Fig. 7, but differs in the striae and the axial and central areas.
+
+Blue clay of Philadelphia. Rare.
+
+Pl. 18, Fig. 8.
+
+
+CYMBELLA TRIANGULUM (EHR.) CL.
+
+Valve semi-elliptical, with acute ends; median line straight; ventral side
+half the width of the dorsal, with straight, slightly convex or concave
+margin; striae radiate, coarsely punctate.
+
+_Gloeonema triangulum_ Ehr.
+
+Baker's Run, Willistown, Pa.
+
+Pl. 18, Fig. 24.
+
+
+CYMBELLA TURGIDA (GREG.) CL.
+
+Valve semi-elliptical, with acute ends; ventral margin gibbous; ventral
+side half the width of the dorsal; median line straight; terminal fissures
+turned downwards; axial area broad; striae radiate, coarsely punctate.
+
+Baker's Run, Willistown, Pa.
+
+Pl. 18, Fig. 23.
+
+
+CYMBELLA TURGIDA (GREG.) CL. VAR. ?
+
+Valve lunate, with gibbous ventral margin; median line straight; terminal
+fissures turned downwards near the ends; axial area lanceolate, striae
+radiate on the dorsal side, 8 in 10 [mu], punctate, 9 on the ventral side,
+closer at the ends where they are convergent. L. 65 [mu]. Not a typical
+form.
+
+Willistown, Pa.
+
+Pl. 18, Fig. 12.
+
+
+CYMBELLA RHOMBOIDEA N. SP.
+
+Valve rhomboidal, with acute ends; dorsal part one and a half times the
+width of the ventral; median line nearly straight, with terminal fissures
+turned downwards near the ends; axial area broad, not widened in the
+middle, except slightly on the ventral side; striae {64}radiate, distant in
+the middle of the dorsal side where they are 7 in 10 [mu], coarsely
+punctate, the puncta in longitudinal lines, 9 in 10 [mu] on the ventral
+side, closer at the ends. L. 69 [mu].
+
+Baker's Run, Willistown, Pa.
+
+Pl. 18, Fig. 11.
+
+
+CYMBELLA GRACILIS (RAB.) CL.
+
+Valve semi-lanceolate, with acute ends; median line nearly straight, with
+terminal fissures turned downwards, distant from the ends; axial area
+linear; ventral margin straight or slightly gibbous in the middle.
+
+Hammonton Pond, N. J.
+
+Pl. 18, Fig. 20.
+
+
+CYMBELLA LACUSTRIS (AG.) CL.
+
+Valve elliptical-lanceolate, with obtuse ends, nearly symmetrical; median
+line straight, terminal fissures distant from the ends; striae radiate in
+the middle, convergent at the ends, coarsely lineate.
+
+Belmar, N. J.
+
+Pl. 18, Fig. 25.
+
+
+AMPHORA EHR. (1840)
+
+(amphora, a jar)
+
+Valves asymmetrical along the longitudinal axis, as in Cymbella, but with
+the plane passing through the dorsal and ventral sides of one valve at an
+angle with that of the other. As Cleve states, Cymbella and Amphora are
+forms of Navicula "with both valves similar and asymmetrical along the
+longitudinal axis," and the difference between Cymbella and Amphora is in
+the "degree of asymmetry." If, following H. L. Smith's diagrams (Lens, Vol.
+2, 1873, p. 66), we assume that the usual form of the valve in Navicula is
+elliptical or lanceolate, and the zone view is rectangular, we have in
+Cymbella an arcuate median line and a more or less reniform valve, while
+the zone view remains rectangular with the valves parallel. Now, if the
+valves are asymmetrical along the longitudinal axis, and one side of one
+valve is separated from the corresponding side of the opposite valve by a
+wider connective zone than is the case on the other side, the transverse
+section of the frustule will appear cuneate, as in Amphora, and the
+connective zone will be wider on one side than the other. When, therefore,
+we examine an entire frustule as it is usually seen, we shall find the two
+raphes of the valves in focus at the same time on the ventral side, and, by
+changing the focus, the convex sides of the same valves are seen, the
+dorsal view with, usually, a wider connective zone. As an illustration,
+compare Figs. 5 and 6, on Plate 15, Fig. 6 being the ventral, and Fig. 5
+the dorsal view.
+
+As Amphorae are epiphytic or parasitic, they are considered, as Cleve
+remarks, like Achnanthes and Cocconeis, as "degenerated forms."
+
+Chromatophores usually single, lying on the ventral connective zone.
+Mereschkowsky describes nine forms.
+
+Cleve divides the genus into a number of groups as follows:
+
+_Amphora proper._--Connective zone not complex; valves with longitudinal
+lines on the dorsal side; coarsely punctate or costate.
+
+_Diplamphora._--Zone complex; otherwise as in Amphora.
+
+_Halamphora._--Longitudinal lines absent; frustule elongate, with
+protracted ends.
+
+{65}_Oxyamphora._--Zone complex; longitudinal lines absent; frustule
+elliptical; valve lunate, with or without a central stauros; striae
+punctate.
+
+_Amblyamphora._--Zone complex; frustule rectangular; valve lunate; striae
+punctate; axial and central areas indistinct.
+
+_Psammamphora._--Zone not complex; frustule rectangular; central nodule
+frequently dilated to a stauros; no axial or central area.
+
+_Cymbamphora._--Valve semi-lanceolate; median line straight, approximate to
+the ventral margin.
+
+
+AMPHORA
+
+AMPHORA ROBUSTA GREG.
+
+Frustule elliptical, truncate; valve lunate, with straight ventral margin;
+median line biarcuate; ventral side with coarse, radiate striae, 6 in 10
+[mu], on both sides of the median line.
+
+Along the coast.
+
+Pl. 15, Fig. 1.
+
+
+AMPHORA PROTEUS GREG.
+
+Frustule elliptical, truncate; valve lunate, with straight ventral margin;
+median line biarcuate; no central area. Striae on the dorsal side not
+interrupted, 9 in 10 [mu]. Ventral side striate toward the ends.
+
+Differs from A. robusta chiefly in size and coarseness of puncta. Extremely
+variable in size.
+
+Common along the coast.
+
+Pl. 15, Figs. 5, 6, and 19.
+
+
+AMPHORA OVALIS (BREB.) KUETZ.
+
+Frustule elliptical, truncate; valve lunate; median line biarcuate; striae
+on dorsal side 10-16 in 10 [mu].
+
+_Var. libyca (Ehr.) Cl._--Central area distinct on the dorsal side.
+
+_Var. pediculus (Kuetz.) Cl._--Central area and nodule quite distinct.
+Striae finer than in var. libyca.
+
+Common in ponds. Quite variable.
+
+Pl. 15, Fig. 7.
+
+
+AMPHORA GIGANTEA VAR. FUSCA A. S.
+
+Frustule elliptical; valve lunate, with straight ventral margin. Axial area
+absent on the dorsal side; dorsal striae, 10 in 10 [mu], punctate. Ventral
+part hyaline except at the ends, which are obliquely striated, with short,
+punctate lines. L. 70-120 [mu].
+
+Absecon, N. J.
+
+Pl. 38, Fig. 1.
+
+
+DIPLAMPHORA
+
+AMPHORA CRASSA GREG.
+
+Valve linear-elliptical, with obtuse, incurved ends. Median line biarcuate.
+Axial and central areas indistinct on the dorsal side; striae coarsely
+punctate, interrupted by a longitudinal line on the dorsal side.
+
+Along the coast.
+
+Pl. 15, Fig. 3.
+
+
+{66}AMPHORA AREOLATA GRUN.
+
+Valve with straight ventral margin; median line straight, approximate to
+the ventral margin; axial area indistinct; several longitudinal lines
+crossed by apparent costae which alternate with rows of fine puncta.
+
+Blue clay. Rare.
+
+Pl. 15, Fig. 11.
+
+
+HALAMPHORA
+
+AMPHORA COFFAEIFORMIS (AG.) KUETZ.
+
+Frustule lanceolate, truncate; zone with numerous divisions. Valve arcuate
+on the dorsal and nearly straight on the ventral side; ends protracted or
+slightly capitate.
+
+_A. aponina_ Kuetz.
+
+_A. salina_ Wm. Sm.
+
+Along the coast.
+
+Pl. 15, Figs. 8 and 18.
+
+
+OXYAMPHORA
+
+AMPHORA LINEOLATA EHR.
+
+Frustule membranaceous, elliptical, truncate, with broad ends. Zone with
+numerous divisions. Dorsal part striated transversely; ventral side with
+longitudinal lines.
+
+_A. plicata_ Greg.
+
+_A. hyalina_ H. L. Smith, Type No. 64.
+
+Along the coast.
+
+Pl. 15, Figs. 9 and 10.
+
+
+AMPHORA OSTREARIA BREB.
+
+Frustule oblong, with rounded angles. Zone with five or more divisions
+transversely striated. Central area narrow, biarcuate; central nodule
+dilated to a stauros. Valve narrow, with arcuate dorsal and straight
+ventral margin, acute at the ends. Striae transverse, finely punctate.
+
+_A. vitraea_ Cl.; _A. porcellus_ Kitton; _A. quadrata_ Breb.; _A. elegans_
+Greg. Appearance varies according to the position of the valve.
+
+Along the coast.
+
+Pl. 15, Figs. 12 and 21.
+
+
+AMPHORA LAEVIS GREG.
+
+Frustule oblong, hyaline and membranaceous. Valve linear or slightly
+arcuate, with ventral margin tumid in the middle; ends obtuse; central
+nodule dilated to a stauros; median line very narrow, biarcuate, coinciding
+with the dorsal margin at the ends; striae transverse, punctate.
+
+Blue clay.
+
+Pl. 15, Fig. 13.
+
+
+AMPHORA ACUTA GREG.
+
+Valve lunate, with acute ends; ventral margin straight; ventral side very
+narrow. Central nodule dilated to a stauros; striae transverse, punctate.
+
+Along the coast.
+
+Pl. 15, Fig. 20.
+
+
+{67}AMBLYAMPHORA
+
+AMPHORA OBTUSA GREG.
+
+Frustule rectangular. Valve linear, obliquely rounded at the ends, with
+arcuate dorsal, and straight ventral, margin; median line biarcuate;
+striae, 18-20 in 10 [mu].
+
+Along the coast. Common.
+
+Pl. 15, Fig. 4.
+
+
+PSAMMAMPHORA
+
+AMPHORA ARENARIA DONK.
+
+Frustule hyaline, rectangular, slightly tumid in the middle, with rounded
+angles. Valve linear with broad ventral side and straight or sinuate
+ventral margin. Striae, 24-27 in 10 [mu] (Cleve).
+
+Common along the coast.
+
+Pl. 15, Fig. 17.
+
+The distinction between A. obtusa and A. arenaria is not always evident if
+the valves alone are seen. The former has a complex zone, the latter a
+simple zone, and the valve has finer striae. Cleve's descriptions and
+references in regard to these two forms do not agree with the descriptions
+and figures of H. L. Smith, or with the figures of Schmidt. The valves of
+most Amphorae are capable of assuming various outlines according to their
+position.
+
+
+AMPHORA OCELLATA VAR. CINGULATA CLEVE
+
+Frustule rectangular. Valve linear, with dorsal margin arcuate and the
+ventral margin straight. Central nodule with a stauros on the dorsal side.
+
+Squan River, N. J.
+
+Pl. 15, Figs. 14 and 15.
+
+
+CYMBAMPHORA
+
+AMPHORA ANGUSTA VAR. EULENSTEINII GRUN.
+
+Valve lanceolate, acute at the ends. Median line straight, approximate to
+the margin. Axial area widened on the dorsal side, indistinct on the
+ventral; striae punctate.
+
+_A. eulensteinii_ A. S.
+
+Common along the coast.
+
+Pl. 15, Fig. 16.
+
+On Pl. 40, Figs. 21, 22, and 23, I have attempted, imitating H. L. Smith's
+figures (Lens, l.c.), to illustrate the difference in the transverse
+sections of Navicula, Cymbella and Amphora.
+
+Fig. 21 represents the transverse section of a convex Navicula, in which
+the valves ecg and fdh are parallel, and the median nodules c and d are
+central.
+
+Fig. 22 is a transverse section of Cymbella in which the valves are nearly
+parallel and the median nodules are excentric. The girdles on one side, ea
+and af, are narrower than gb and bh on the other side.
+
+Fig. 23 is a transverse section of an Amphora in which the valves appear in
+zone view with the median nodules of both valves on the same side. The
+girdles on the ventral side, ea and af, are narrower than gb and bh on the
+dorsal side. The girdles on the dorsal side are seldom as broad as gb and
+bh, the valve extending over a great part of the dorsal side to g' and h'.
+
+
+{68}AMPHIPRORA EHR. (1843)
+
+(amphi, on both ends, and prora, a prow)
+
+Frustule twisted in the longitudinal axis, constricted in the middle; zone
+complex, with numerous divisions crossed by fine striae. Valve lanceolate,
+acute. The raphe confined within a sigmoid keel or extension of the valve;
+the central and terminal nodules indistinct. Striae transverse, punctate,
+with coarser striae at the junction of the keel and lower part of the
+valve.
+
+Chromatophores single, with indented border except in A. pulchra, in which
+there are two chromatophores with entire borders.
+
+
+AMPHIPRORA ALATA KUETZ.
+
+Frustule with a row of puncta at the junction line. Valve linear, acute at
+the ends. Median line sigmoid. Striae lineate on the lower part of the
+valve, punctate on the keel.
+
+Along the coast. Not common.
+
+Pl. 14, Fig. 3.
+
+
+AMPHIPRORA PULCHRA BAIL.
+
+Frustule with sigmoid connective zone. Valve very convex, with sinuate keel
+and junction lines evident. In zone view and in valve view, one half of the
+frustule, owing to the elevation of the keel, is wider than the other half.
+Striae punctate, coarser on the keel.
+
+Not uncommon along the coast.
+
+Pl. 14, Figs. 1 and 2.
+
+
+AMPHIPRORA CONSPICUA GREV.
+
+Valve linear or elliptical, with acute ends. Median line sigmoid, but the
+junction lines not evident. Striae lineate, with coarser lines near the
+middle.
+
+Not common. Port Penn, Delaware River.
+
+Pl. 14, Fig. 4.
+
+
+AMPHIPRORA ORNATA BAIL.
+
+Frustule membranaceous, constricted in the middle, with well-marked folds
+extending from the junction line in both directions. Valve lanceolate,
+constricted in the middle and with protracted ends. Keel undulate on the
+edge.
+
+A beautiful, transparent and delicate form, the only fresh-water species in
+our locality.
+
+Delaware Water Gap, Pa.
+
+Pl. 14, Figs. 6 and 7.
+
+
+AMPHIPRORA PALUDOSA WM. SM.
+
+Frustule membranaceous, constricted, with truncate ends. Valve linear, with
+acute ends. Striae scarcely visible.
+
+Cape May (Cleve).
+
+Pl. 14, Fig. 5.
+
+
+TROPIDONEIS CLEVE (1891)
+
+(tropis, a keel)
+
+Frustule oblong, constricted in the middle; keel not sigmoid. Axial area
+not evident. Striae very fine, punctate, in longitudinal lines.
+
+
+{69}TROPIDONEIS LEPIDOPTERA (GREG.) CLEVE
+
+Valve with straight, median excentric line. Keel unilateral, projecting
+above the median line in zone view; central area small. Transverse striae
+finely punctate. As usually seen, the valve is inclined. According to
+Karsten there are two chromatophores on the connective zone, each divided
+into four parts, each of which contains a large oval pyrenoid.
+
+_Amphiprora lepidoptera_ Greg.
+
+Along the coast.
+
+Pl. 14, Figs. 8 and 9.
+
+
+AURICULA CASTRACANE (1873)
+
+(auricula, the ear, the shape of the valve)
+
+Frustule globose. Valve reniform or cymbiform, elevated into a keel which
+is not sigmoid. Median line biarcuate. Differs from Amphiprora in not
+having a sigmoid keel.
+
+
+AURICULA MUCRONATA (H. L. SMITH) PERAGALLO
+
+In zone view, the median line deeply bisects the longitudinal axis, ending
+in a mucronate central nodule. Connective zone complex. Valve very complex,
+with ventral margin nearly straight and raphe excentric. Central nodule
+near the margin, terminal nodules small. Striae, 35-40 in 10 [mu] (Cleve).
+Chromatophore single, on the ventral part.
+
+_Amphora mucronata_ H. L. Smith.
+
+_Amphora (?) insecta_ Grun.
+
+_Auricula insecta_ (Grun.) Cleve.
+
+"A rare and very curious pelagic species" (Peragallo, Diat. Villefranche).
+
+Prof. H. L. Smith included this form in his first century of "Species
+Typicae Diatomacearum," which was issued prior to 1876, the date of
+publication, in Schmidt's Atlas, of Amphora insecta Grun.
+
+Atlantic City, N. J. Rare.
+
+Pl. 15, Fig. 2.
+
+
+SCOLIOTROPIS CLEVE (1894)
+
+(scolios, twisted, and tropis, a keel)
+
+Frustule linear, oblong. Median line sigmoid near the ends. Valve with
+transverse costae alternating with two intermediate rows of puncta in
+oblique lines.
+
+
+SCOLIOTROPIS LATESTRIATA VAR. AMPHORA CLEVE
+
+Valve asymmetrical, with the median line curved. Frustule sub-acute at the
+ends. Median lines not on the same side of each valve of the frustule.
+
+Abundant at Cape May, N. J. Not common elsewhere.
+
+Pl. 14, Figs. 10 and 11.
+
+
+GOMPHONEIS CLEVE (1894)
+
+(gomphos, a peg, and neis (naus))
+
+Valve elongated, asymmetrical to the transverse axis; axial area narrow;
+central area rounded, stigmatic; striae radiating, costae alternating with
+double rows of fine puncta. An indistinct, longitudinal line near the
+border.
+
+Chromatophores and conjugation have not been determined.
+
+
+{70}GOMPHONEIS HERCULANEUM (EHR.) CL.
+
+Valve clavate, with rounded apex; costae, 13 in 10 [mu], alternating with
+double rows of fine puncta, 22 in 10 [mu], in oblique rows; axial area
+narrow, central area rounded, with one stigma.
+
+_Gomphonema capitatum_ Ehr var. _herculaneum_ Ehr., H. L. S., Type Slide
+No. 177.
+
+Common in the blue clay.
+
+Pl. 19, Fig. 2.
+
+Pl. 38, Fig. 15, zone view of young frustule.
+
+
+GOMPHONEIS MAMILLA (EHR.) CL.
+
+Valve lanceolate, with rounded apex and base; striae costate, 10 in 10
+[mu], alternating with double rows of fine puncta; axial area linear,
+sometimes oblique, central area small, with one or more stigmas.
+
+Blue clay. Rare.
+
+Pl. 19, Fig. 1.
+
+In one frustule I noticed one valve with one stigma and the other with four
+stigmas.
+
+The difference between G. mamilla and G. elegans is not very great. In the
+latter the central area is larger and the longitudinal lines not so near to
+the margin. The stigmas form a circlet. There appears to be a coincidence
+in the relation of Gomphoneis to Gomphonema, and that of the true
+Achnanthes to the group described by Cleve under Achnanthidium. In
+Gomphoneis and Achnanthes the striation is both costate and punctate while
+in Gomphonema and Achnanthidium the striation is punctate only.
+
+
+GOMPHONEMA AG. (1824)
+
+(gomphos, a peg, and nema, a filament)
+
+Valve elongated, asymmetrical with respect to the transverse axis; striae
+transverse, usually radiate, punctate.
+
+Chromatophore band single, the middle lying on one zone.
+
+In conjugation, according to Thwaites and Pfitzer, from two mother cells,
+which do not form a positive union, two auxospores are developed parallel
+to the original frustules. In Plate 19, Fig. 19, I have drawn a
+representation of the auxospore formation as I have frequently observed it
+in a gathering sent me by Mr. T. C. Palmer, containing G. angustatum, a
+common species in this locality. The sagittal plane of the valve of the
+auxospore is at right angles to the plane of the valve of the mother cell.
+Two valves of one of the mother cells are seen separated, one on each side
+of the auxospore which is nearly twice the length of the original
+frustules. The two valves of the other mother cell are not shown as they
+are not usually found closely united. In the figure one valve alone of the
+auxospore is seen, the opposite valve not being in focus. The valves of the
+auxospore are usually more or less arcuate, as in Cymbella, to which the
+genus is closely allied.
+
+Grunow divides Gomphonema into two groups, Asymmetricae and Symmetricae,
+according to the presence or absence of stigmas. Cleve suggests Stigmaticae
+and Astigmaticae as more suitable in order to agree with the Cymbellae. The
+Stigmaticae are found chiefly in fresh water, sometimes in brackish. All of
+the marine forms belong to the Astigmaticae, which, however, include some
+common fresh-water forms. Many species of Gomphonema are stipitate, some
+occur in gelatinous masses, and others are free.
+
+
+{71}GOMPHONEMA MONTANUM SCHUM.
+
+Valve slightly biconstricted, with obtuse apex and basis, somewhat cuneate;
+axial area linear, widened in the middle unilaterally; stigma, one; striae
+about 11 in 10 [mu], more distant in the middle, punctate.
+
+_Gomphonema subclavatum_ var. _montana_ (Schum.) Cl.
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 19, Fig. 3.
+
+
+GOMPHONEMA GEMINATUM LYNG.
+
+Valve biconstricted, with large, rounded, sub-truncate apex and broad,
+sub-truncate basis; striae, 9 in 10 [mu], radiate in the middle,
+alternately longer and shorter, transverse at the basis and near the apex
+where they again radiate, coarsely punctate, puncta, 12 in 10 [mu]. Axial
+area linear; central area rounded, with several large stigmas in a
+longitudinal row; terminal fissures hook-shaped.
+
+Blue clay.
+
+Pl. 19, Fig. 4.
+
+
+GOMPHONEMA LANCEOLATUM VAR. INSIGNIS (GREG.) CL.
+
+Valve lanceolate; axial area narrow; central area unilateral with one
+stigma; striae with coarse and distant puncta.
+
+Common and variable.
+
+_Gomphonema insigne_ Greg.
+
+Pl. 19, Figs. 6 and 12.
+
+Fig. 12 shows a unilateral central area. Fig. 6 is more clavate in outline
+with small central area. In both forms the coarse puncta are in distinct
+longitudinal lines in the middle.
+
+
+GOMPHONEMA ACUMINATUM VAR. TURRIS (EHR.) CL.?
+
+Valve clavate, with cuneate, acute apex; axial area distinct; central area
+unilateral with one stigma.
+
+Blue clay.
+
+Pl. 19, Fig. 11.
+
+
+GOMPHONEMA ACUMINATUM VAR. TURRIS (EHR.) CL.
+
+Valve clavate, with cuneate apiculate apex and narrow basis; axial area
+narrow, with a unilateral central space; stigma opposite the short striae;
+striae more radiate in the upper part, distant in the middle.
+
+Smith's Island, Delaware River.
+
+Pl. 19, Fig. 5.
+
+
+GOMPHONEMA ACUMINATUM VAR. CORONATA (EHR.) CL.
+
+Valve twice constricted, with broad, cuneate apex; striae radiate in the
+middle, convergent near the apex and radiate at the apex. Variable in size
+and outline.
+
+Blue clay. Fresh water. Common.
+
+Pl. 19, Fig. 7.
+
+
+GOMPHONEMA ACUMINATUM VAR. TRIGONOCEPHALA (EHR.) CL.
+
+Valve broad, with cuneate apex; axial area narrow; central area unilateral
+with one stigma.
+
+Pavonia, N. J., artesian well.
+
+Pl. 19, Fig. 20.
+
+
+{72}GOMPHONEMA CONSTRICTUM EHR.
+
+Valve clavate, constricted beneath the abruptly rounded apex, gibbous in
+the middle, striae alternately longer and shorter; axial area narrow,
+central area unilateral, with one stigma.
+
+Common in fresh water.
+
+Pl. 19, Fig. 8.
+
+
+GOMPHONEMA SPHAEROPHORUM EHR.
+
+Valve clavate, with capitate or rostrate-capitate apex and narrow basis;
+axial area very narrow; central area small, unilateral, with one stigma.
+
+Common in fresh water.
+
+Pl. 19, Figs. 9 and 10. Fig. 10 appears to be a transitional form having a
+more distinct axial area and rostrate apex.
+
+
+GOMPHONEMA AUGUR EHR.
+
+Valve broadly clavate, truncate and apiculate at the apex; basis sub-acute;
+axial area distinct; central area small, unilateral with one stigma; striae
+with distant puncta.
+
+Blue clay. Willistown, Pa.
+
+Pl. 19, Fig. 21.
+
+
+GOMPHONEMA INTRICATUM KUETZ.
+
+Valve narrow, lanceolate, slightly gibbous in the middle; axial area
+distinct; central area transverse with one stigma; striae parallel. Quite
+variable.
+
+Common in fresh water.
+
+Pl. 19, Fig. 14.
+
+
+GOMPHONEMA ANGUSTATUM KUETZ.
+
+Valve lanceolate, with sub-rostrate apex and basis; axial area indistinct;
+central area unilateral, with one small stigma; striae slightly radiate,
+indistinctly punctate.
+
+Very common in fresh water.
+
+Pl. 19, Figs. 18 and 19.
+
+Fig. 19, as stated above, represents the formation of an auxospore.
+
+
+GOMPHONEMA AEQUALE GREG.
+
+Valve linear-lanceolate, nearly symmetrical, with capitate apex and basis;
+axial area narrow; central area unilateral, with one stigma; striae radiate
+in the middle, slightly convergent at the ends.
+
+_Gomphonema intricatum var. aequale_ (Greg.) Cl.
+
+Blue clay. Not common.
+
+Pl. 19, Fig. 15.
+
+
+GOMPHONEMA SARCOPHAGUS GREG.
+
+Valve linear, irregular in outline, with rounded apex and basis; axial area
+distinct; central area small, unilateral, with one stigma; striae irregular
+with coarse, distinct puncta.
+
+Occasional in fresh water.
+
+Pl. 19, Fig. 16.
+
+
+GOMPHONEMA CAPITATUM EHR.
+
+Valve clavate, broad at the sub-truncate apex and slightly constricted, or
+with parallel margins; axial area linear, central area stellate, with one
+stigma; striae in the middle alternately longer and shorter.
+
+Blue clay.
+
+Pl. 19, Fig. 22.
+
+
+{73}GOMPHONEMA PARVULUM VAR. MICROPUS (KUETZ.) CL.
+
+Valve clavate, with rounded apex and basis; axial area indistinct; central
+area unilateral, with a small stigma; striae distant in the middle.
+
+Common.
+
+Pl. 19, Fig. 17.
+
+
+GOMPHONEMA VENTRICOSUM GREG.
+
+Valve clavate, with broad apex and produced, rounded basis; axial area
+narrow, widened in the middle; stigma one; striae distant in the middle,
+finely punctate.
+
+Blue clay.
+
+Pl. 19, Fig. 13.
+
+
+GOMPHONEMA OLIVACEUM LYNG.
+
+Valve clavate, with broad apex and narrow basis; axial area very narrow;
+central area irregular, without stigma; striae radiate, finely punctate.
+
+Very common.
+
+Pl. 19, Fig. 23.
+
+
+GOMPHONEMA BRASILIENSE VAR. DEMERARAE GRUN.?
+
+Valve lanceolate, with sub-cuneate apex and narrowed basis; axial area
+lanceolate, broad; no stigma; median fissures remote; striae parallel, 12
+in 10 [mu], punctate, the puncta obsolescent, small or interrupted.
+
+Willistown, Pa. Rare.
+
+Pl. 19, Fig. 24.
+
+
+PLEUROSIGMA WM. SM. (1852)
+
+(pleura, a side, and sigma, the letter s)
+
+Valve lanceolate, sigmoid; axial area very narrow, central area small;
+striae punctate, in transverse and oblique lines.
+
+Cleve divides the forms usually known as Pleurosigma into two genera,
+Pleurosigma and Gyrosigma. Pleurosigma includes all forms having oblique
+rows of puncta, while Gyrosigma includes all having longitudinal rows. Both
+have transverse striae. The former consists entirely of marine species,
+while in the latter the species are found in fresh, brackish and salt
+water.
+
+The endochrome in Pleurosigma, according to Mueller, consists of two bands
+which differ in the median part of each valve. Mereschkowsky says that the
+endochrome is so divided as to form four bands, two on each valve, that
+their position is different in different species, and that they are not the
+same on valves of the same frustule.
+
+Cleve prefers to classify the species of Pleurosigma and Gyrosigma in
+accordance with the outline of the valve and the flexure of the median
+line. I shall, however, retain the method used by Peragallo and Grunow and
+arrange the forms according to the striation.
+
+
+(1) OBLIQUE STRIAE ABOUT 90 DEGREES, MORE DISTINCT THAN THE TRANSVERSE
+
+PLEUROSIGMA FORMOSUM WM. SM.
+
+Valve elongated, slender, gently sigmoid, acute at the ends; oblique striae
+crossing each other at about 90 degrees; 10-16 in 10 [mu]; transverse
+striae, 14-20 in 10 [mu] (Cleve).
+
+Along the coast.
+
+Pl. 22, Fig. 5.
+
+
+{74}PLEUROSIGMA OBSCURUM WM. SM.
+
+Valve linear, not sigmoid, or scarcely so; ends obtuse, subconical; raphe
+sigmoid, near the margin at the extremities; transverse and oblique striae
+equidistant, 28 in 10 [mu] (Wm. Sm.).
+
+Abundant at Greenwich Point, Philadelphia.
+
+Pl. 22, Fig. 4.
+
+
+(2) OBLIQUE STRIAE CLOSER AT THE ENDS
+
+PLEUROSIGMA NAVICULACEUM BREB.
+
+Valve lanceolate, slightly sigmoid at the extremities; raphe strongly
+sigmoid near the margin at the ends; central nodule large, rounded; oblique
+striae, 13-14 in the middle, closer at the ends; transverse striae, 18-20
+in 10 [mu] (Peragallo).
+
+Long Island Sound.
+
+Pl. 22, Fig. 6.
+
+
+PLEUROSIGMA VIRGINIACUM H. L. SMITH
+
+Valve slightly sigmoid, with acute ends; raphe more sigmoid than the valve,
+excentric near the ends; oblique striae in different directions at the
+centre, 13 in 10 [mu], closer and less distinct at the ends; central nodule
+small but prominent because of its thickness, producing by diffraction an
+apparently wide area (somewhat exaggerated in the figure). L. 95 [mu],
+usually larger.
+
+_P. affine_ var. _fossilis_ Grun. (Peragallo).
+
+_P. normanii_ var. _fossilis_ Grun. (Cleve).
+
+Common in the blue clay.
+
+Pl. 22, Fig. 8.
+
+
+(3) OBLIQUE STRIAE 60 DEGREES
+
+PLEUROSIGMA ANGULATUM (QUEKETT) CL.
+
+Valve rhomboidal, with sub-rostrate or produced ends; central nodule
+rhomboidal; raphe central; transverse and oblique striae at an angle of 60
+degrees, equidistant, 18-22 in 10 [mu].
+
+_Navicula angulata_ Quekett.
+
+Along the coast.
+
+Pl. 22, Fig. 3.
+
+
+PLEUROSIGMA STRIGOSUM WM. SM.
+
+Valve lanceolate, with sub-acute, somewhat revolute, apices; oblique striae
+at an angle of about 60 degrees, otherwise as in angulatum.
+
+Along the coast. Not common.
+
+Pl. 22, Fig. 1.
+
+
+PLEUROSIGMA AESTUARII BREB.
+
+Valve lanceolate, with produced apices; raphe less sigmoid than the valve
+and excentric; oblique striae, 19-21 in 10 [mu], at an angle of about 60
+degrees.
+
+Along the coast. Common.
+
+Pl. 22, Fig. 7.
+
+
+{75}(4) OBLIQUE STRIAE 60 DEGREES, THE TRANSVERSE MORE DISTANT
+
+PLEUROSIGMA RIGIDUM WM. SM.
+
+Valve nearly straight or slightly sigmoid, with obtuse ends; raphe central,
+excentric near the ends; oblique striae, 17-21, transverse, 16-19 in 10
+[mu]. (Peragallo).
+
+New Rochelle, N. Y.
+
+Pl. 22, Fig. 2 (very near the var. gigantea Grun.)
+
+
+GYROSIGMA HASSALL (1845)
+
+(gyros, curved, and sigma)
+
+Valve lanceolate, sigmoid; axial area very narrow, central area small;
+striae punctate, in transverse and longitudinal rows.
+
+Chromatophores two, in long and narrow bands, perforated, differing from
+those of Pleurosigma. The elaeoplasts are also arranged differently in the
+two genera. (Mereschkowsky, Etudes sur l'Endochrome des Diatomees, Imperial
+Academy of Petrograd, 1901, Vol. 11, No. 6, p. 18 et seq.)
+
+The arrangement is according to Peragallo.
+
+
+(1) LONGITUDINAL STRIAE MORE DISTANT THAN THE TRANSVERSE
+
+GYROSIGMA HIPPOCAMPUS (EHR.)
+
+Valve lanceolate, sigmoid, with obtuse ends; raphe nearly central;
+transverse striae 15-17, longitudinal, 10-12 in 10 [mu].
+
+_Navicula hippocampus_ Ehr.
+
+_Pleurosigma hippocampus_ (Ehr.) Wm. Sm.
+
+_Gyrosigma attenuatum_ (Kuetz.) Cl.
+
+Long Island Sound.
+
+Pl. 23, Fig. 3.
+
+
+(2) LONGITUDINAL AND TRANSVERSE STRIAE NEARLY EQUAL
+
+GYROSIGMA BALTICUM (EHR.) CL.
+
+Valve with margins parallel nearly to the extremities, which are suddenly
+unilaterally sub-conical and obtuse; raphe sigmoid; transverse and
+longitudinal striae nearly equally distant, 15 in 10 [mu] (Per.). L.
+200-360 [mu].
+
+_Navicula baltica_ Ehr.
+
+_Pleurosigma balticum_ (Ehr.) Wm. Sm.
+
+Common along the coast.
+
+Pl. 23, Fig. 2.
+
+
+GYROSIGMA PARKERI VAR. STAURONEIOIDES GRUN.
+
+Valve lanceolate, slightly sigmoid, ends produced into beaks with sub-acute
+apices; raphe straight in the middle part; central nodule elliptical;
+transverse striae, 21, and longitudinal, 24 in 10 [mu] (Per.).
+
+An apparent stauros, variable in width, extends to the margin and, in
+consequence, the median transverse striae are more evident. L. 75 [mu].
+
+Schuylkill River. Rather rare.
+
+Pl. 23, Fig. 7.
+
+
+{76}GYROSIGMA SIMILE (GRUN.)
+
+Valve slightly sigmoid, broad, with obtuse ends; raphe sigmoid, nearly
+central; transverse striae, 15, longitudinal, 16-17 in 10 [mu] (Per.).
+
+_Pleurosigma simile_ Grun.
+
+_Gyrosigma balticum_ var. _similis_ (Grun.) Cl.
+
+Shark River, N. J.
+
+Pl. 23, Fig. 4.
+
+
+(3) TRANSVERSE STRIAE MORE DISTANT
+
+GYROSIGMA ACUMINATUM (KUETZ.) CL.
+
+Valve sigmoid, tapering to the sub-acute ends; raphe central; transverse
+and longitudinal striae nearly equally distant, 17 or 18 in 10 [mu] (Per.).
+
+_Frustulia acuminata_ Kuetz.
+
+Port Penn, Delaware River.
+
+Pl. 23, Fig. 5.
+
+
+GYROSIGMA STRIGILIS (WM. SM.) CL.
+
+Valve sigmoid, with obtuse ends; raphe doubly sigmoid; axial area rather
+wide; transverse striae, 13, and longitudinal, about 16 in 10 [mu].
+
+Long Island Sound. Not common.
+
+Pl. 23, Fig. 1.
+
+
+GYROSIGMA KUETZINGII (GRUN.) CL.
+
+Valve sigmoid, lanceolate, with sub-acute ends; raphe central, the central
+nodule elliptical; transverse striae, 21-23, and longitudinal, 25-26 in 10
+[mu].
+
+_Pleurosigma spencerii_ var. _acutiuscula_ Grun.
+
+_Pleurosigma spencerii_ var. _kuetzingii_ Grun.
+
+Common in fresh water.
+
+Pl. 38, Fig. 12.
+
+
+GYROSIGMA SCALPROIDES (RAB.) CL.
+
+Valve slightly sigmoid, with obtuse ends; raphe nearly straight; central
+nodule elliptical; transverse striae, 22, slightly radiate and more distant
+in the middle; longitudinal striae, 29 in 10 [mu]. L. 60 [mu].
+
+Common in streams.
+
+Pl. 38, Fig. 9.
+
+In Pl. 23, Fig. 6 represents a form more sigmoid.
+
+
+GYROSIGMA SPENCERII VAR. NODIFERA GRUN.
+
+Valve sigmoid, with obtuse ends; raphe central; central nodule obliquely
+elongated; transverse striae, 17-18 in 10 [mu], curved in the middle of the
+valve, longitudinal striae, 22 in 10 [mu]. L. 150 [mu].
+
+Blue clay.
+
+Pl. 23, Fig. 8.
+
+
+GYROSIGMA PROLONGATUM (WM. SM.) CL.
+
+Valve narrow, lanceolate, produced into beaks, curved in a contrary
+direction; raphe central; transverse striae, 20-21 in 10 [mu], longitudinal
+closer. L. 140 [mu].
+
+Along the coast, northward.
+
+Pl. 38, Fig. 13.
+
+I have not seen any specimens south of New England, but they will probably
+occur.
+
+
+{77}(4) STRIAE ALIKE, EXTREMITIES PRODUCED
+
+GYROSIGMA FASCIOLA (EHR.) CL.
+
+Valve lanceolate, attenuated into curved beaks turned in opposite
+directions; raphe central, straight, except at the beaks; transverse
+striae, 22, longitudinal, 24 in 10 [mu] (Per.).
+
+New York Bay.
+
+Pl. 23, Fig. 9.
+
+
+FRUSTULIA AG. (1824); em. GRUN. (1865)
+
+(frustulum, a small piece)
+
+Valves naviculoid, similar, usually free but sometimes enclosed in
+gelatinous tubes or embedded in mucus. Median line between two thickened
+ribs. Central and terminal nodules frequently elongated. Surface of valve
+with fine puncta in longitudinal and transverse lines appearing hyaline
+under medium powers.
+
+Chromatophores, two, extending along the girdle. They differ from those of
+Navicula in being separated from the wall in the middle by a hemispherical
+mass of protoplasm. According to Pfitzer, each chromatophore is divided in
+the middle, allowing a connection between the hemispherical mass and the
+central plasma mass. Schmitz states that the chromatophore is thickened in
+the middle and contains a pyrenoid.
+
+In conjugation, two frustules form two cylindrical bodies which later
+become conical and from which are formed the sporangial valves twice the
+usual size.
+
+
+FRUSTULIA LEWISIANA (GREV.) DE TONI
+
+Valve elliptical or linear, with rounded ends; terminal nodules elongated,
+at a distance from the ends; striae, 24 in 10 [mu].
+
+Port Penn, Delaware River. Along the coast.
+
+Pl. 17, Fig. 1.
+
+
+FRUSTULIA RHOMBOIDES (EHR.) DE TONI
+
+Valve lanceolate or rhombic-lanceolate, rounded at the ends; central and
+terminal nodules short; striae, 20 in 10 [mu], sometimes coarser.
+
+Common in fresh water.
+
+Pl. 17, Fig. 2.
+
+
+FRUSTULIA RHOMBOIDES VAR. AMPHIPLEUROIDES GRUN.
+
+Valve rhombic-lanceolate; central and terminal nodules elongated; median
+line somewhat excentric.
+
+Blue clay.
+
+Pl. 17, Fig. 3.
+
+
+FRUSTULIA RHOMBOIDES VAR. SAXONICA (RAB.) DE TONI
+
+Valve smaller than in rhomboides, with somewhat produced ends, closer
+median ribs and rounded central nodule.
+
+Fresh water.
+
+Pl. 17, Fig. 6.
+
+
+FRUSTULIA VULGARIS (THWAITES) DE TONI
+
+Valve elliptical-lanceolate, with rounded or sometimes sub-rostrate ends;
+central and terminal nodules slightly elongated; striae delicate, closer at
+the ends. Frustules at first in gelatinous tubes.
+
+_Colletonema vulgaris_ Thwaites.
+
+Fresh water.
+
+Pl. 17, Fig. 4.
+
+
+{78}FRUSTULIA INTERPOSITA (LEWIS) DE TONI
+
+Valve linear-elliptical, rounded at the ends; terminal nodules short.
+
+_Navicula interposita_ Lewis.
+
+Along the coast. Port Penn, Delaware River.
+
+Pl. 17, Fig. 5.
+
+
+AMPHIPLEURA KUETZ. (1844)
+
+(amphi, on both sides, pleura, a side)
+
+Frustules free, in gelatinous masses or in tubes. Valve linear-lanceolate;
+central nodule narrow, extending half the length of the valve or more, then
+forking toward the ends. Terminal nodules prolonged, as in Frustulia, into
+a "porte-crayon-shaped" figure.
+
+Chromatophores two, very short.
+
+
+AMPHIPLEURA PELLUCIDA KUETZ.
+
+Frustules free or in mucous masses. Valve fusiform; forks about one-fourth
+the length of the valve; striae transverse, punctate, 36-40 in 10 [mu] (J.
+J. Woodward).
+
+Occasional in the Delaware River.
+
+Pl. 17, Fig. 9.
+
+
+AMPHIPLEURA RUTILANS (TRENTEPOHL) CL.
+
+Frustules enclosed in gelatinous tubes. Valve linear-lanceolate, obtuse at
+the ends; forks about one-third the length of the valve; striae, 28 in 10
+[mu].
+
+_Conferva rutilans_ Trentepohl.
+
+_Schizonema dillwynii_ Wm. Sm.
+
+Abundant at Belmar, N. J.
+
+Pl. 17, Fig. 10.
+
+Fig. 11 represents a portion of the gelatinous tube containing frustules.
+
+
+DICTYONEIS CLEVE (1890)
+
+(dictyon, a net)
+
+Frustules oblong. Valve lanceolate, constricted in the middle (in our
+species); an outer layer finely punctate and an inner layer of
+reticulations; the margin of the valve divided into large, quadrate cells.
+
+The genus Dictyoneis includes species at one time ascribed to Mastogloia
+and Navicula. The structure, however, is not like that of either, as the
+loculi are attached to the valve and are not separable as in Mastogloia,
+and the cell-wall is not like that of any Navicula.
+
+Cleve remarks that Dictyoneis is found in warm waters. Lewis found one
+specimen at Black Rock Harbor, L. I., and one in the Delaware River blue
+clay. The specimens here described I found living on the New Jersey coast.
+
+
+DICTYONEIS MARGINATA VAR. TYPICA CLEVE
+
+Valve panduriform, with cuneate lobes; axial area narrow, linear, scarcely,
+or not at all, widened in the middle; terminal fissures in contrary
+directions; outer stratum finely punctate, about 25 in 10 [mu], in parallel
+striae; inner stratum coarsely reticulated. Four and one-fourth times
+longer than broad; marginal cells, 5 in 10 [mu], smaller or obsolescent in
+the middle of the valve; cells of the valve in irregular transverse rows,
+10-12 in 10 [mu]. L. 93 [mu].
+
+_Navicula marginata_ Lewis.
+
+Absecon, N. J.
+
+Pl. 20, Fig. 3.
+
+
+{79}DICTYONEIS MARGINATA VAR. COMMUTATA CLEVE
+
+Valve four and one-half times longer than broad; cells of the valve in
+irregular, transverse rows about 11 in 10 [mu]; marginal cells nearly
+equal, 6 in 10 [mu]. L. 125 [mu].
+
+Absecon, N. J.
+
+Pl. 20, Fig. 2.
+
+
+DICTYONEIS MARGINATA VAR. MAXIMA N. VAR.
+
+Valve with cuneate segments; marginal cells, 4 in 10 [mu]; cells of the
+valve, 5 in 10 [mu], obsolescent in the middle and smaller; transverse
+striae, 25 in 10 [mu].
+
+Atlantic Coast. Rare.
+
+Pl. 20, Fig. 1 (from a specimen found at Colon).
+
+
+TRACHYNEIS CLEVE (1894)
+
+(trachys, rough, and neis (naus), named from the chief species)
+
+Valve more or less linear or linear-lanceolate. It appears to be composed
+of three strata, one an interior, coarsely dotted, an exterior of fine
+puncta in longitudinal striae, scarcely visible, and a median of transverse
+anastomosing costae forming irregular alveoli.
+
+Chromatophores, two or four bands on the zone (Mereschkowsky).
+
+
+TRACHYNEIS ASPERA VAR. INTERMEDIA GRUN.
+
+Valve linear-elliptic; axial area a stauros widened outward and unilateral.
+Striae of the median layer of radiating rows of oblong alveoli.
+
+Along the coast. Not common.
+
+Pl. 17, Fig. 15.
+
+The type form and its numerous varieties are quite ubiquitous. Very large
+specimens occur in the Antarctic regions, especially in material from Ross
+Island, S. Victoria Land (Shackleton Ant. Exp.).
+
+
+BREBISSONIA GRUN. (1860)
+
+(named after Alphonse de Brebisson, the distinguished French naturalist)
+
+Frustules stipitate; valve lanceolate; striae transverse in the middle,
+radiate at the ends. Median area narrow, central nodule elongated, terminal
+fissures at a distance from the ends. Valve with an outer finely punctate
+stratum.
+
+At one end of one valve in each frustule is found a conspicuous punctum,
+the plasma pore of Otto Mueller, through which the frustule is connected
+with the gelatinous stipe, analogous to the pore in Diatoma connecting the
+zig-zag frustules.
+
+Chromatophore single, lying on one girdle and passing over to each valve.
+
+
+BREBISSONIA BOECKII (KUETZ.) GRUN.
+
+Valve lanceolate, with sub-acute apices; striae, 3-4 in 10 [mu], not
+reaching the median line.
+
+Blue clay. Very rare. Common in brackish water at Chestertown, Md. (T. C.
+Palmer)
+
+Pl. 17, Fig. 7.
+
+
+{80}BREBISSONIA PALMERII, N. SP.
+
+Valve rhombic-lanceolate, with cuneate ends and produced apices. Central
+nodule more elongate and terminal fissures further from the ends than in B.
+boeckii.
+
+Pavonia, N. J. (artesian well, depth of 40 ft.). Rare.
+
+Pl. 17, Fig. 8.
+
+I take pleasure in naming this species after Mr. T. Chalkley Palmer, of
+Media, Pa., the author of numerous papers on the Diatomaceae.
+
+Lewis partly describes a similar form, which he does not name, as a species
+of Navicula found in the blue clay at Kaighn's Point, N. J. (Lewis, "New
+and Intermediate Forms," etc., p. 15, Pl. 1, Fig. 8.)
+
+
+ANOMOEONEIS PFITZER (1871)
+
+(anomoios, unlike, and neis (naus), a boat)
+
+Valve lanceolate, axial area narrow, central area widened; transverse
+striae punctate, the puncta in longitudinal rows or interrupted by blank
+lines.
+
+A single chromatophore lies along one of the girdle sides and extends over
+the valves, each of the two parts being deeply notched or slit at the ends.
+According to Schmitz there are two pyrenoids, but Heinzerling thinks there
+is but one.
+
+Cleve considers this genus not well founded, as it is based upon the cell
+contents of but one species, the structure of the other species not being
+known. As the forms here described are easily recognized by the interrupted
+puncta, the genus is, at least, convenient.
+
+
+ANOMOEONEIS SPHAEROPHORA (KUETZ.) CL.
+
+Valve elliptic-lanceolate, ends rostrate-capitate. Axial area narrow,
+central area rounded, larger on one side of the median line than the other.
+Striae very slightly radiate, 16 in 10 [mu], punctate, the puncta
+interrupted by longitudinal blank lines.
+
+Pfitzer states that the central plasma mass is unequal on the two sides.
+
+_Navicula sphaerophora_ Kuetz.
+
+Fresh and brackish water. Not common.
+
+Pl. 40, Fig. 2.
+
+
+ANOMOEONEIS SERIANS (BREB.) CL.
+
+Valve lanceolate, acute; axial area lanceolate; striae, 24 in 10 [mu];
+puncta elongate.
+
+Not common in this locality, but abundant northwards; fossil in the peat
+deposits of New England.
+
+May's Landing, N. J.
+
+Pl. 17, Fig. 12.
+
+Forma minor--Valve rhombic-lanceolate, smaller than the type.
+
+May's Landing, N. J.
+
+Pl. 17, Fig. 13.
+
+
+ANOMOEONEIS FOLLIS (EHR.) CL.
+
+Valve rhomboid, tumid in the middle and obtuse at the produced ends.
+Central area lanceolate; striae radiate in the middle, transverse at the
+ends.
+
+_Navicula follis_ Ehr.
+
+_Navicula trochus_ Kuetz.
+
+{81}Reported by Lewis as very rare in the blue clay of the Delaware River.
+I have not seen it in this locality. The figure is drawn from a specimen in
+the W. Bridgewater, Mass., deposit.
+
+Pl. 17, Fig. 14.
+
+
+CALONEIS CLEVE (1894)
+
+(calos, beautiful)
+
+Valve convex, linear or lanceolate in general outline, with transverse,
+smooth or finely punctate striae crossed by one or more longitudinal lines.
+
+Endochrome of two chromatophores lying one on each valve, entire in some
+species and deeply cleft in others.
+
+
+CALONEIS LIBER (WM. SM.) CL.
+
+Valve linear, with parallel margins and rounded ends; axial area narrow,
+central area orbicular; striae transverse in the middle, slightly divergent
+at the ends, 16 in 10 [mu]; terminal fissures slightly curved in the same
+direction; longitudinal line median. L. 82 [mu].
+
+Atlantic coast, chiefly southward.
+
+Pl. 40, Fig. 1.
+
+
+CALONEIS SILICULA (EHR.) CL.
+
+Valve linear, gibbous in the middle, with broad sub-cuneate ends; axial
+area narrow, central area rounded; longitudinal line marginal; striae
+parallel or nearly so, 16 to 18 in 10 [mu].
+
+_Navicula silicula_ Ehr.
+
+_Navicula limosa_ Donk.
+
+Blue clay.
+
+Pl. 21, Fig. 3 (var. genuina Cl.).
+
+
+CALONEIS SILICULA VAR. INFLATA (GRUN.) CL.
+
+Valve gibbous in the middle, with rounded ends; central area elliptical.
+
+Schuylkill River.
+
+Pl. 21, Fig. 4.
+
+C. silicula may be recognized by its yellow color when dry. Its varieties
+are extremely numerous.
+
+
+CALONEIS TRINODIS (LEWIS)
+
+Valve divided into three segments of equal width; ends cuneate and usually
+produced; axial area elliptical with a lunate marking on each side; striae
+radiate in the middle, elsewhere parallel, about 20 in 10 [mu], finely
+punctate; longitudinal line marginal, scarcely visible; the striae become
+fainter toward the axial area.
+
+Occasional in streams and in the blue clay. Abundant in a water-trough at
+Ashbourne, Pa.
+
+Pl. 21, Fig. 8.
+
+I have retained Lewis' name as specific. Lewis, wrongly, I think, ascribes
+his species to _Navicula trinodis_ Wm. Sm., which is not figured by Smith,
+but is illustrated by Van Heurck (Syn. Pl. 14, Fig. 31a), and is named by
+Cleve _Navicula contenta_ var. _biceps_ Arnott. {82}De Toni includes Lewis'
+name under _Rhoiconeis trinodis_ (Wm. Sm.) Grun. Rhoiconeis is
+achnanthiform, with frustules arcuate, and the species is named by Cleve
+_Achnanthes trinodis_ (Arnott). _Caloneis schumanniana_ (Grun.) Cl., to
+which as a variety Cleve unites Lewis' form, appears to resemble it only in
+the lunate marks.
+
+Fig. 9 represents a single specimen found in the Pavonia deposit and which
+I believe to be an abnormal form of C. trinodis, differing only in the
+degree of inflation and in the larger central area.
+
+_Navicula trinodis_ var. _inflata_ Schultze, from Staten Island, is the
+same form figured by Lewis, who states that certain specimens have produced
+apices.
+
+
+CALONEIS PERMAGNA (BAIL.) CL.
+
+Valve lanceolate, with produced apices; median line nearly straight; axial
+area lanceolate, irregular or slightly unilateral, about half the width of
+the valve; striae, 9 in 10 [mu], radiate and indistinctly punctate;
+longitudinal lines double. L. 100-200 [mu].
+
+_Pinnularia permagna_ Bail.
+
+Common in brackish water.
+
+Pl. 21, Fig. 1.
+
+
+CALONEIS PERMAGNA VAR. LEWISIANA N. VAR.
+
+Valve lanceolate, with undulating sides and sub-cuneate apices; axial area
+less than one-third the width of the valve; striae radiate, 12 in 10 [mu],
+indistinctly punctate; longitudinal lines double, closer together than in
+the type. L. 140 [mu].
+
+Lewis illustrates this variety in "New and Rare Species," Pl. 2, Fig. 11,
+and states that it is probably Navicula esox Kuetzing. This is an error, as
+Kuetzing's species is Pinnularia esox Ehr., a form near P. major.
+
+Rather common in the Delaware River.
+
+Pl. 21, Fig. 2.
+
+
+CALONEIS FORMOSA (GREG.) CL.
+
+Valve lanceolate, with sub-cuneate apices; axial area one-fourth to
+one-fifth the width of the valve, somewhat unilateral, dilated in the
+middle; striae, 12-14 in 10 [mu] radiate, punctate; longitudinal lines
+double, distinct. Variable in size and outline.
+
+Abundant along the shores of the Delaware River.
+
+Pl. 21, Fig. 18.
+
+
+CALONEIS BREVIS VAR. VEXANS (GRUN.) CL.
+
+Valve elliptical-lanceolate; apices obtuse; median fissures distant; axial
+area narrow; central area large, orbicular; longitudinal lines close
+together, median.
+
+Shark River, N. J.
+
+Pl. 21, Fig. 5.
+
+
+CALONEIS WARDII CL.
+
+Valve linear, ends cuneate; axial area linear; central area dilated to a
+stauros reaching the margin; striae parallel, radiate at the ends, 18 in 10
+[mu]; longitudinal lines marginal.
+
+Not uncommon in the Delaware River.
+
+Pl. 21, Figs. 6 and 7.
+
+
+{83}CALONEIS POWELLII (LEWIS) CL.
+
+Valve linear, with cuneate ends; axial area linear; central area large,
+quadrate, united to the wide longitudinal lines; striae parallel, smooth, 8
+in 10 [mu].
+
+Long Island (Lewis); Smith's Island, Delaware River.
+
+Pl. 21, Fig. 10.
+
+
+NEIDIUM PFITZER (1871)
+
+(neidion, dim. of naus, a boat)
+
+Valve linear or lanceolate; median fissures turned in opposite directions,
+terminal fissures appearing bifurcate (?); striae transverse, usually
+oblique, finely punctate, crossed by one or several longitudinal blank
+lines.
+
+Chromatophores, two, lying on the girdle side, in cell division each
+forming a partially divided pair. A large pyrenoid is said to be found in
+the middle of each chromatophore, but Mereschkowsky states that the
+pyrenoids are absent, but that in N. affine four elaeoplasts are always
+seen in the centre of the frustule.
+
+A genus easily recognized by the peculiar terminal and median fissures and
+by the yellowish or brownish color of the valves when dry, darker than in
+Caloneis.
+
+
+NEIDIUM AFFINE (EHR.) PFITZER
+
+Valve linear, with protracted, sub-rostrate or capitate ends.
+
+_Navicula affinis_ Ehr.
+
+
+NEIDIUM AFFINE VAR. GENUINA FORMA MAXIMA CL.
+
+Striae, 14 in 10 [mu], punctate, oblique in the middle, convergent at the
+ends; puncta, 15 in 10 [mu]. L. 238 [mu].
+
+Pensauken, N. J. (artesian well).
+
+Pl. 21, Fig. 11.
+
+Var. genuina forma minor Cl.--L. 26 [mu]; striae, 24 in 10 [mu].
+
+Brandywine Creek.
+
+Pl. 21, Fig. 12.
+
+
+NEIDIUM AFFINE VAR. AMPHIRHYNCUS (EHR.) CL.
+
+Valve linear, with protracted capitate ends; striae transverse, interrupted
+by several longitudinal lines.
+
+Willistown, Pa.
+
+Pl. 21, Fig. 13.
+
+
+NEIDIUM AMPHIGOMPHUS (EHR.) PFITZER
+
+Valve with parallel margins and cuneate ends; striae transverse,
+interrupted by several longitudinal lines; central area widened
+transversely.
+
+_Navicula amphigomphus_ Ehr.
+
+Wissahickon.
+
+Pl. 21, Fig. 14.
+
+
+NEIDIUM PRODUCTUM (WM. SM.) CL.
+
+Valve linear, elongate, with capitate apices; striae slightly oblique;
+longitudinal lines marginal; axial area very narrow, central area small.
+
+_Navicula producta_ Wm. Sm.
+
+Newtown Square.
+
+Pl. 21, Fig. 16.
+
+
+{84}NEIDIUM IRIDIS (EHR.) CL.
+
+Valve linear or lanceolate-elliptical, with sub-cuneate or rounded ends;
+striae oblique, about 18 in 10 [mu]; central area orbicular.
+
+_Navicula iridis_ Ehr.
+
+_Navicula firma_ Kuetz.
+
+Willistown, Pa.; Middletown, Delaware Co., Pa. (Palmer).
+
+Pl. 21, Fig. 17.
+
+The form here figured is probably the variety ampliata (Ehr.) Cl. with less
+acute apices and more elliptical outline. The species occurs in many
+variations, the larger being found northward, especially in the peat
+deposits of New England.
+
+
+NEIDIUM HITCHCOCKII (EHR.) CL.
+
+Valve linear, with triundulate margin and cuneate ends; striae transverse,
+oblique.
+
+_Navicula hitchcockii_ Ehr.
+
+Pavonia, N. J. (artesian well); Kirkwood Pond, N. J.
+
+Pl. 21, Fig. 15.
+
+
+DIPLONEIS EHR. (1840)
+
+(diplos, double)
+
+Valve elliptical or panduriform; median line enclosed in strongly siliceous
+horns corresponding to the lyre-shaped areas of Navicula lyra but never
+punctate; central nodule, quadrate; valve costate, or striate, or both;
+between the horns and the outer part are thinner spaces or sulci, and, in
+some species, outside of the sulci are narrow spaces known as lunulae.
+
+Chromatophores, two, upon the girdle or the valves. Pyrenoids have been
+found in one species only, D. interrupta.
+
+
+DIPLONEIS ELLIPTICA (KUETZ.) CL.
+
+Valve elliptical; central nodule large; sulci narrow, curved, close to the
+horns; striae punctate, in rows radiating more and more toward the ends.
+Variable in size and in the coarseness of puncta which are from 10 to 13 in
+10 [mu] (Cleve).
+
+Cleve describes D. ovalis Hilse as having the central nodule rounded, but
+otherwise about the same as D. elliptica, and as equivalent to Navicula
+ovalis A. Schmidt (Atlas, Pl. 7, Figs. 33 to 36).
+
+Very common in fresh water and occasional in brackish.
+
+Pl. 20, Fig. 14.
+
+
+DIPLONEIS SMITHII (BREB.) CL.
+
+Valve elliptical; central nodule not broad; furrows evenly curved on the
+outer edge, crossed by costae and double oblique rows of alveoli. Variable
+in size and in the curvature of the furrows.
+
+Cleve forms a new species, D. major, of the large form figured by Schmidt
+(Atlas, Pl. 7, Figs. 18, 19, 21 and 22), stating that the structure is much
+coarser and the form is larger with broad furrows. In the specimen here
+figured the size is median and the furrows are as in D. major.
+
+Marine and brackish. Common.
+
+Pl. 20, Fig. 17.
+
+
+{85}DIPLONEIS CRABRO VAR. PANDURA (BREB.) CL.
+
+Valve constricted, segments tongue-shaped; central nodule small; horns
+narrow, nearly parallel, with a row of large puncta; costae, 4 in 10 [mu],
+convergent in the middle, radiating at the ends, alternating with a double
+row of puncta, 11 in 10 [mu].
+
+Pavonia, N. J. (artesian well).
+
+Pl. 20, Fig. 4.
+
+
+DIPLONEIS CRABRO VAR. EXPLETA (A. S.) CL.
+
+Valve slightly constricted, segments tongue-shaped; costae robust, 5 or 6
+in 10 [mu], alternating with double rows of rather coarse puncta. L. 56
+[mu].
+
+Port Penn, Delaware River.
+
+Pl. 20, Fig. 15.
+
+
+DIPLONEIS CRABRO VAR. PANDURELLA CL.?
+
+Valve constricted, the lobes elliptical; central nodule large, with horns
+parallel in the middle, convergent at the ends; furrows wide, with faint
+costae; no lunula; costae parallel in the middle, radiate at the ends, 9 in
+10 [mu], alternating with very fine double rows of puncta (not shown in the
+figure). L. 65 [mu].
+
+Blue clay.
+
+Pl. 20, Fig. 13.
+
+
+DIPLONEIS CRABRO VAR.?
+
+Valve constricted, segments elliptical; costae, 8 in 10 [mu], converging in
+the middle, radiating at the ends; horns narrow; furrows wide, costate;
+lunulae indistinct. L. 75 [mu].
+
+Resembles var. pandurella except in the convergence of the costae and in
+the lunula.
+
+Squan River. Marine.
+
+Pl. 20, Fig. 9.
+
+
+DIPLONEIS FUSCA VAR. DELICATA (A. S.) CL.
+
+Valve elliptical; furrows broad, crossed with rows of faint costae and
+alveoli; costae, 6 or 7 in 10 [mu]; alveoli, 10 in 10 [mu], in short,
+irregular, longitudinal rows. L. 84 [mu].
+
+Port Penn, Delaware River.
+
+Pl. 20, Fig. 11.
+
+
+DIPLONEIS GRUENDLERI (A. S.) CL.
+
+Valve constricted, segments tongue-shaped, often unequal; horns broad,
+divergent in the middle; furrows narrow; costae transverse, crossed by from
+3 to 7 longitudinal costae, interrupted in the middle at the border.
+
+Blue clay.
+
+Pl. 20, Figs. 7 and 8.
+
+
+DIPLONEIS PUELLA (SCHUM.) CL.
+
+Valve elliptical, sometimes orbicular; furrows very narrow; striae, 20 in
+10 [mu], indistinct. L. 15 [mu].
+
+_Diploneis elliptica_ var. _minutissima_ Grun.
+
+Shark River, N. J. Brackish.
+
+Pl. 20, Fig. 12.
+
+
+DIPLONEIS EXCENTRICA, N. SP.
+
+Valve elliptical; central nodule quadrate; furrows of the same width
+throughout, nearly parallel; costae radiating toward the ends, 10 in 10
+[mu], indistinct on the furrows, alternating with alveoli, 7 in 10 [mu], in
+irregular, longitudinal lines. One side of the valve is one and a half
+times the width of the other. L. 49 [mu].
+
+{86}I can find neither description nor figure of any species to which I can
+ascribe this form. It approaches D. elliptica. The alveoli are quite
+distinct and distant from each other.
+
+Brackish water. Very abundant in a gathering from Squan River, N. J.
+
+Pl. 20, Fig. 10.
+
+
+DIPLONEIS OCULATA (BREB.) CL.
+
+Valve elliptical; striae radiate at the ends, about 20 in 10 [mu], coarsely
+punctate. L. 23 [mu].
+
+Fresh water.
+
+Pl. 26, Fig. 7.
+
+The figure is drawn from Brebisson's original material in H. L. Smith's
+Type Slide No. 299.
+
+_Navicula oculata_ Breb.
+
+Reported from New Jersey. I have not seen this species in this locality.
+Navicula oculata, referred to by Kain as occurring in Shark River, is not
+this form.
+
+
+DIPLONEIS GEMMATA (GREV.) CL.
+
+Valve oblong-linear, with cuneate ends and parallel or slightly concave
+sides; central nodule large; horns parallel; furrows about one-third the
+width of the valve. Costae about 5 in 10 [mu], alternating with double rows
+of fine puncta; short costae occur along the borders of the horns.
+
+Port Penn, Delaware River.
+
+Pl. 20, Fig. 16.
+
+
+DIPLONEIS CAMPYLODISCUS (GRUN.) CL.
+
+Valve suborbicular; central nodule quadrate; horns divergent; costae, 6 in
+10 [mu], alternating with double rows of alveoli; furrows broad, costate
+near the horns.
+
+Differs from Cleve's description in having 6, instead of 4, costae in 10
+[mu].
+
+Pensauken, N. J. (artesian well). Rare.
+
+Pl. 20, Fig. 6.
+
+
+MASTOGLOIA THWAITES (1856)
+
+(mastos, a breast, and gloios, gelatinous, referring to the "mamillate
+cushion" in which the frustules are often immersed)
+
+Frustule rectangular. Valves similar, naviculoid. Central and axial areas
+usually narrow or indistinct; striae punctate, parallel in the middle. On
+each side, between the valve and the zone, is a septate plate.
+
+
+ANALYSIS OF SPECIES
+
+
+  Striae interrupted by a hyaline furrow on each side of
+    the median line                                           kinsmanii
+
+  Striae not interrupted:
+
+    Loculi, five, or less                                     exigua
+
+          more than five, equal, ending at distance from
+             the ends                                         smithii
+
+            ending near the ends, distinct                    lanceolata
+
+                                  indistinct                  elegans
+
+            very numerous                                     apiculata
+
+            unequal                                           angulata
+
+{87}Karsten states that there are two chromatophores, each of which extends
+from the middle of one valve to the end and down the middle of the other
+valve. Mereschkowsky says, however, that there are four plates or
+chromatophores, sometimes on the valve, sometimes on the zone, according to
+the species, and that two long pyrenoids unite the two opposite
+chromatophores.
+
+
+MASTOGLOIA KINSMANII LEWIS
+
+Valve lanceolate-elliptical, with sub-rostrate ends; loculi more numerous
+than in M. angulata but less than in M. apiculata, the middle ones larger.
+Median line with a sulcus on each side; central area quadrate.
+
+_Mastogloia braunii_ Grun. (According to Cleve).
+
+Atlantic City.
+
+Pl. 17, Fig. 16.
+
+
+MASTOGLOIA EXIGUA LEWIS
+
+Valve elliptical- or linear-lanceolate; loculi, 2-5, usually 3, larger in
+the middle and rounded; central space small; striae, 20-24 in 10 [mu].
+
+Along the coast.
+
+Pl. 17, Fig. 24.
+
+
+MASTOGLOIA SMITHII THWAITES
+
+Valve lanceolate, sub-rostrate; loculi forming a wide band ending at a
+distance from the ends; striae transverse, with puncta forming longitudinal
+rows; central area rounded or transversely elliptical.
+
+Along the coast.
+
+Pl. 17, Fig. 19.
+
+
+MASTOGLOIA LANCEOLATA THWAITES
+
+Valve lanceolate, with sub-rostrate apices; loculi very numerous; median
+and central areas indistinct; striae, 19 in 10 [mu], punctate, convergent
+at the ends.
+
+Along the coast.
+
+Pl. 17, Fig. 18.
+
+
+MASTOGLOIA ELEGANS LEWIS
+
+Valve lanceolate, acute; loculi indistinct or rudimentary, extending to the
+ends; central area apparently quadrate, sometimes indistinct; puncta
+distinct, 15 in 10 [mu], in transverse and longitudinal rows.
+
+Along the coast. Common.
+
+Pl. 17, Fig. 20.
+
+
+MASTOGLOIA APICULATA WM. SM.
+
+Valve elliptical-lanceolate, sometimes with slightly produced apices;
+median line between two ribs; central space very small; loculi numerous;
+puncta in slightly radiating rows and in longitudinal lines.
+
+Along the coast.
+
+Pl. 17, Figs. 21, 22, 23.
+
+
+MASTOGLOIA ANGULATA LEWIS
+
+Valve elliptical, with produced apices; loculi usually less than 12,
+unequal, the larger in the middle; striae, 12 in 10 [mu], puncta in
+decussating rows. "Differs from apiculata in its more broadly elliptical
+shape, the smaller number of its loculi and the angular character of its
+striation" (Lewis).
+
+{88}Considered by Cleve as synonymous with M. apiculata Grun., not Wm.
+Smith, and by De Toni as synonymous with M. apiculata Wm. Sm. In any case,
+M. angulata Lewis is not the same as M. apiculata Wm. Sm., the loculi of
+which are equal.
+
+Atlantic City. H. L. Smith T. S. No. 211.
+
+Pl. 17, Fig. 17.
+
+
+STAURONEIS EHR. (1843)
+
+(stauros, a cross, and neis (naus), a boat)
+
+Frustules free, sometimes geminate; valve as in Navicula but with a
+stauros. Cell contents as in Navicula. Mereschkowsky, however, says that
+the chromatophores always contain more pyrenoids than are found in
+Navicula. Heinzerling gives the number as two to four in each
+chromatophore.
+
+Cleve includes under Naviculae Microstigmaticae all species of Stauroneis,
+Pleurostauron, Schizostauron, certain Schizonemae and Naviculae. As a
+matter of convenience, and because I have already included certain
+Schizonemae and Scoliopleura under Navicula, and because of the small
+number of species in our locality, I have arranged them under the three
+divisions of Cleve as follows:
+
+_Stauroneis._--Forms having a true stauros, without diaphragms.
+
+_Pleurostauron._--Forms like Stauroneis but with diaphragms at the ends.
+
+_Schizostauron._--Forms having a bifid stauros.
+
+
+STAURONEIS PHOENICENTERON EHR.
+
+Valve lanceolate, obtuse; striae radiate, 18 in 10 [mu], distinctly
+punctate. L. usually 125 [mu] but sometimes 200 [mu].
+
+Common in fresh water.
+
+Pl. 27, Fig. 1.
+
+
+STAURONEIS ANCEPS EHR.
+
+Valve lanceolate, with rostrate or capitate ends; stauros in some cases
+does not reach the margin. The varieties are very numerous.
+
+_Var. gracilis (Ehr.) Cl._--Valve lanceolate, striae very fine; margin of
+stauros striated. L. 100 [mu]. Cape May, N. J. Pl. 27, Fig. 5.
+
+_Var. amphicephala (Kuetz.) Cl._--Valve capitate at the ends; striae, 24 in
+10 [mu]. L. 47 [mu]. Fresh water. Pl. 27, Fig. 7.
+
+_Var. ?_--Valve with produced ends; striae, 30 or more in 10 [mu]. L. 104
+[mu]. Willistown, Pa. Pl. 27, Fig. 4.
+
+_Var. ?_--Valve with produced ends; striae, about 28 in 10 [mu], punctate.
+L. 47 [mu]. Newtown Square. Pl. 27, Fig. 8.
+
+_Var. ?_--Valve with produced ends; striae, 22 in 10 [mu], showing a
+tendency to form longitudinal rows of puncta as in Stauroneis stodderi
+Greenleaf, but the rows are not so evident. L. 60 [mu]. Pavonia, N. J.,
+artesian well. Pl. 27, Fig. 9.
+
+
+STAURONEIS FRICKEI VAR. ANGUSTA N. VAR.
+
+Valve lanceolate, gradually tapering to the obtuse ends; terminal fissures
+prominent, forking at a distance of 7 [mu] from the ends. Frustules
+frequently geminate. L. 173 [mu].
+
+Newtown Square. Rare.
+
+Pl. 26, Fig. 18.
+
+Near Stauroneis frickei A. S. (Atlas, Pl. 242, Fig. 16), except that the
+stauros is narrow at the margin.
+
+
+{89}STAURONEIS SALINA WM. SM.
+
+Valve lanceolate, obtuse; stauros narrow, with short, scattered striae at
+the margin, 18 in 10 [mu], punctate. L. 65 [mu].
+
+Along the coast. Common.
+
+Pl. 27, Fig. 6.
+
+
+STAURONEIS LEGUMEN EHR.
+
+Valve elliptical-lanceolate, inflated in the middle, with produced
+sub-capitate or rostrate ends separated by diaphragms. Stauros wide,
+striated at the margins; axial area very narrow; striae radiate, about 26
+(?) in 10 [mu], punctate. L. 28 [mu].
+
+Pavonia, N. J., artesian well.
+
+Pl. 39, Fig. 15.
+
+In Cleve's description and Van Heurck's figure, the median inflation is
+"not larger than the others." In the present form the median inflation is
+wider.
+
+
+STAURONEIS ACUTA WM. SM.
+
+Valve rhombic-lanceolate, obtuse; a diaphragm at each end; stauros widened
+outwards; striae, 15 or 16 in 10 [mu], punctate. L. 130 [mu].
+
+Blue clay.
+
+Pl. 27, Fig. 2.
+
+
+STAURONEIS AMERICANA A. S.
+
+Valve elliptical-lanceolate, obtuse; striae, 14 in 10 [mu]. L. 119 [mu].
+
+Pavonia, N. J., artesian well. Rare.
+
+The only specimen found is asymmetrical with respect to the transverse
+axis.
+
+On Plate 40, Fig. 4, is illustrated an abnormal form of Stauroneis,
+apparently near S. acuta, having an elongated central nodule and radiating,
+curved and coarsely punctate striae. Blue clay.
+
+
+STAURONEIS SMITHII GRUN.
+
+Valve lanceolate, inflated in the middle and at the ends, which have
+diaphragms and are produced into rostrate apices; stauros reaching the
+margin; striae parallel, about 25 in 10 [mu] (28 to 30, Cleve), distinctly
+punctate.
+
+Not uncommon in meadow pools near Newtown Square.
+
+Pl. 27, Fig. 11.
+
+
+STAURONEIS CRUCICULA (GRUN.) CL.
+
+Valve lanceolate, with obtuse, produced ends; stauros bifid; striae, 24 in
+10 [mu], oblique, parallel to the branches of the stauros, closer at the
+ends, punctate. L. 32 [mu].
+
+Newtown Square. East Park Reservoir. Rare.
+
+Pl. 27, Fig. 10.
+
+
+NAVICULA BORY (1826)
+
+(dim. of navis, a boat)
+
+Valve linear to elliptical; ends acute, rounded, rostrate, capitate or
+truncate; axial area usually distinct; central area distinct, rounded or
+rarely extended into a transverse fascia; striae transverse or radiate,
+punctate; central area not dilated into a transverse stauros nor into
+horns.
+
+{90}The endochrome in the greater number of species consists of two
+chromatophores extending along the zone and sometimes partly over the
+valves. Sometimes, however, as in N. hennedyi, N. lyra and N. humerosa, the
+bands are on the valves. Certain species have four bands, others eight, and
+in one the endochrome is granular. (Mereschkowsky, l. c., p. 9 et seq.)
+Pyrenoids are usually absent. On account of the diversity of the
+chromatophores, Mereschkowsky considers the genus not homogeneous. The
+difficulty of arranging groups according to the cell contents, however, is
+so great that, for the present, the species must be described by the usual
+characteristics of the valves and divided as follows, according to Cleve,
+to the extent of employing the classification of all Naviculoid forms as
+applicable, especially to the species of Navicula. Van Heurck's analysis
+includes Pinnularia, Trachyneis, Diploneis, Caloneis, Neidium and
+Anomoeoneis, which are here separated, while N. lyra and N. hennedyi are
+placed in different groups, although they are closely related. In other
+respects Cleve's divisions correspond, to some extent, to those of Van
+Heurck.
+
+The genus Navicula at one time included the following: Dictyoneis,
+Pleurosigma, Gyrosigma, Caloneis, Neidium, Diploneis, Frustulia,
+Trachyneis, Anomoeoneis, Pinnularia and Stauroneis, and few forms with a
+raphe escaped. For this reason the diagnosis of the present genus is
+somewhat limited. Pleurosigma and Gyrosigma differ from Navicula in their
+outline, Dictyoneis in the double stratification, Caloneis in the marginal
+lines, Neidium in the median and terminal fissures, Diploneis in the horns,
+Frustulia in the terminal nodules, Trachyneis in the stratification of the
+valve, Anomoeoneis in the longitudinal arrangement of the puncta,
+Pinnularia in the smooth costae and Stauroneis in the stauros.
+
+As the object of the present work is to aid the student of local forms in
+the identification of species by the briefest methods, the further
+discussion of the reasons for classification will be left for his
+gratification in referring to the authorities on the subject.
+
+
+PUNCTATAE CLEVE
+
+Valve elliptical to lanceolate; central nodule not stauroid or continued
+into lyriform spaces; striae distinctly or coarsely punctate, in radiate
+rows.
+
+
+NAVICULA MACULATA (BAIL.) CL.
+
+Valve lanceolate-elliptical, with produced or sub-rostrate ends; axial area
+narrow, wider near the ends and dilated to a rounded, transverse central
+area; striae radiate, 6 in 10 [mu], puncta, 7 in 10 [mu], in irregular,
+longitudinal rows. L. 90 to 120 [mu] (Cl.).
+
+_Stauroneis maculata_ Bail.
+
+_Navicula fischeri_ A. S.
+
+Blue clay. Along the coast, especially southward.
+
+Pl. 24, Fig. 1.
+
+
+NAVICULA LATISSIMA GREG.
+
+Valve oblong-elliptical or elliptical-lanceolate, with sub-cuneate ends;
+axial area lanceolate, widened in the middle to an orbicular space; striae
+radiate, 7 in 10 [mu], puncta, 11 in 10 [mu], the median striae alternating
+with short striae along the sides. L. 50-150 [mu] (Cl).
+
+Blue clay. Pavonia, N. J., artesian well.
+
+Pl. 24, Fig. 3.
+
+
+{91}NAVICULA LATISSIMA VAR. ELONGATA (PANT.) CL.
+
+Valve elliptical-lanceolate, with rounded ends; striae and puncta closer
+than in the type form; axial area narrow, widened in the middle; terminal
+fissures hook-shaped, turned in different directions.
+
+_Navicula humerosa_ var. _elongata_ Pant.
+
+Fossil at Buckshutem, N. J.
+
+Pl. 24, Fig. 5.
+
+
+NAVICULA FUCHSII PANT.
+
+Valve elliptical, with slightly produced apices; axial area wide,
+lanceolate; central area orbicular; striae alternately longer and shorter
+in the middle, 10-12 in 10 [mu]; puncta on the border of the axial area
+larger, elongated; median fissures incrassate.
+
+_Navicula humerosa_ var. _fuchsii_ (Pant.) Cl.
+
+_Navicula_ (_latissima_ var.?) _fuchsii_ Pant.
+
+Port Penn, Delaware River.
+
+Pl. 24, Fig. 6.
+
+
+NAVICULA HUMEROSA BREB.
+
+Valve lanceolate-elliptical or oblong-elliptical, with sub-cuneate or
+sub-rostrate ends; axial area narrow, lanceolate; central area rounded,
+somewhat transverse; terminal fissures hook-shaped, in the same direction;
+central pores incrassate; striae, 11 in 10 [mu], the middle alternately
+longer and shorter, closer at the ends. L. 60-86 [mu]. Variable in size,
+outline and fineness of striation.
+
+N. monilifera Cleve (N. granulata Breb.) differs in having coarser striae.
+
+Blue clay. Along the coast.
+
+Pl. 25, Fig. 5.
+
+
+NAVICULA PUSILLA WM. SM.
+
+Valve ovate-elliptical, with rostrate or sub-rostrate ends; axial area
+narrow; central area elliptical; striae radiate, 10-12 in 10 [mu] in the
+middle where they are longer and shorter alternately, closer at the ends;
+median fissures somewhat incrassate, terminal in the same direction. L. 47
+[mu].
+
+Smith's Island, Delaware River.
+
+Pl. 25, Figs. 4, 6?
+
+Cleve gives the striae as 13-18 in the typical form, and 11-13 in
+varieties. In the form here figured the striation is as stated by De Toni,
+but is about 19 at the ends.
+
+Fig. 6 appears to be a small form of N. pusilla, near lanceolata Grun., at
+least according to the figure in "Arctic Diatoms," but not Gregory's
+figure. It occurs rarely in fresh water at Newtown Square. It may be a
+small form of N. punctulata and, if so, is probably accidental, as the
+material is entirely fresh-water.
+
+
+NAVICULA PUSILLA VAR. SUBCAPITATA N. VAR.
+
+Valve elliptical with rostrate-capitate and truncate ends; striae about 12
+in 10 [mu] in the middle where they are unequal; axial area narrow,
+slightly widened in the middle; central pores incrassate, terminal fissures
+in the same direction. Differs from type in outline and centre.
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 25, Fig. 8.
+
+
+{92}NAVICULA DELAWARENSIS GRUN.
+
+Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow,
+lanceolate, widened in the middle; striae about 10 in 10 [mu]; in the
+middle, much closer at the ends; puncta in the middle, 9 in 10 [mu], closer
+and much smaller at the ends. L. 58-95 [mu].
+
+Cleve (Le Diatomiste, Vol. 2, p. 14) states that this form is very near N.
+pusilla but is much larger. Specimens from Smith's Island measure 58-65
+[mu], from Wildwood, 95 [mu] in length.
+
+Pl. 25, Fig. 3.
+
+
+NAVICULA PUNCTULATA WM. SM.
+
+Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow,
+central area rounded; striae, 11 in 10 [mu], closer at the ends, a few
+shorter in the middle; puncta, 10 in 10 [mu]. L. 54 [mu].
+
+_Navicula marina_ Ralfs.
+
+Port Penn, Delaware River (brackish water).
+
+Pl. 25, Fig. 9.
+
+"Although this species is described as marine in the Synopsis of Prof.
+Smith, I have never found it in purely marine localities" (Donkin).
+
+
+NAVICULA PUNCTATA VAR. ASYMMETRICA LAGERSTEDT
+
+Valve lanceolate, with rostrate ends; axial area narrow, central area
+transverse, irregular; striae radiate, punctate, 12 in 10 [mu]. L. 36 [mu].
+
+_Navicula amphibola_ Cleve.
+
+Blue clay.
+
+Pl. 27, Fig. 15.
+
+
+NAVICULA BRASILIENSIS VAR. BICUNEATA CL., FORMA CONSTRICTA
+
+Valve oblong-elliptical, slightly constricted, with cuneate-rostrate ends;
+axial area narrow; central area dilated transversely and unilaterally;
+striae, 9 in 10 [mu]; puncta closer at the border and in irregular
+longitudinal rows in the middle; terminal fissures small, hook-shaped,
+turned in the same direction. L. 93 [mu].
+
+Corresponds closely to Cleve's variety except in the constriction.
+
+Blue clay.
+
+Pl. 25, Fig. 2.
+
+
+NAVICULA LACUSTRIS GREG.
+
+Valve lanceolate, sub-acute; axial area narrow; central area orbicular;
+striae radiate, 14 in 10 [mu], punctate, the median puncta sometimes more
+distant than the others.
+
+Blue clay. Rare.
+
+Pl. 27, Fig. 12.
+
+
+LYRATAE CL.
+
+Valve elliptical or elliptical-lanceolate; striae punctate, transverse;
+axial area narrow or indistinct; central area expanded on each side into
+lyre-shaped or horn-like blank spaces.
+
+
+NAVICULA PRAETEXTA EHR.
+
+Valve elliptical; lateral areas not regular, with scattered puncta; striae
+radiate, 5 or 6 in 10 [mu]; puncta, 7 or 8 in 10 [mu]; along the axial
+area, a single or double row of puncta; at {93}the middle of the border, on
+each side, two striae approach each other closely with a short stria
+between them; terminal fissures small, in the same direction. L. 120 [mu].
+
+Port Penn, Delaware River.
+
+Pl. 24, Fig. 2.
+
+While variable in size and striation, approaching N. hennedyi, this
+species, as here figured, is found in the Miocene and later deposits and is
+extant in most parts of the world.
+
+
+NAVICULA IRRORATA GREV.
+
+Valve oblong-elliptical, with cuneate-rostrate ends; striae, 7 or 8 in 10
+[mu], puncta, 7 in 10 [mu]; axial area bordered by puncta in unequal,
+transverse rows. L. 84 [mu].
+
+Blue clay. Rare.
+
+Pl. 24, Fig. 4.
+
+
+NAVICULA HENNEDYI WM. SM.
+
+Valve elliptical; areas semilanceolate; striae about 11 in 10 [mu],
+sometimes longer and shorter on the margin; short rows of transverse striae
+along the axial area.
+
+Blue clay.
+
+Pl. 25, Fig. 12.
+
+_Var. circumsecta Grun._--As in the type but with the lateral areas faintly
+striate or punctate.
+
+_Var. manca A. S._--Valve lanceolate-elliptical, the lateral areas narrow
+and convergent toward the ends; short rows of transverse striae along the
+axial area; striae, 9 in 10 [mu]; central pores incrassate.
+
+Blue clay.
+
+Pl. 25, Fig. 11.
+
+
+NAVICULA LYRA EHR.
+
+Valve elliptical, with rounded, sub-rostrate or sub-cuneate ends; lateral
+areas narrow; striae, 6 to 14 in 10 [mu] (Cl.), punctate. L. 50-180 [mu].
+
+_Var. ehrenbergii Cl._--Lateral areas constricted in the middle, divergent
+at the ends. Cleve refers to Schmidt, Atlas, Pl. 2, Fig. 25, which is not
+divergent at the ends.
+
+Along the coast.
+
+Pl. 25, Fig. 10.
+
+A narrower form occurs which has the areas divergent.
+
+_Var. ?_--Valve elliptical, lateral areas narrow, convergent at the ends
+with short rows of punctate striae; marginal striae, 10 in 10 [mu],
+punctate. L. 60 [mu].
+
+Squan River, N. J.
+
+Pl. 20, Fig. 5.
+
+_Var. dilatata A. S._--Valve elliptical, rostrate; lateral areas convergent
+in the middle and nearly parallel or convergent at the ends.
+
+Blue clay.
+
+Pl. 25, Fig. 13.
+
+N. lyra is exceedingly variable in outline, fineness of striation and in
+the lateral areas. Intermediate forms occur approaching N. hennedyi and N.
+spectabilis. In N. hennedyi the lateral areas are broad, semilanceolate,
+not narrowed in the middle. In N. spectabilis the lateral areas are broad
+and narrowed in the middle. In N. lyra the lateral areas are narrow and
+either constricted or not in the middle. In many forms in {94}these three
+species the lateral areas are more or less striated or punctate. Cleve does
+not consider this a distinction of any importance, although certain
+varieties are founded upon it. All three species are very common in the
+blue clay and along the coast, but their varieties are too numerous to
+describe or figure.
+
+
+NAVICULA SPECTABILIS VAR. EMARGINATA CL.
+
+Valve elliptical; lateral areas broad, narrowed in the middle, delicately
+striated; marginal striae, 10 in 10 [mu]. L. 70 [mu].
+
+Blue clay.
+
+Pl. 25, Fig. 7.
+
+
+NAVICULA PYGMAEA KUETZ.
+
+Valve elliptical, appearing hyaline; axial and central areas faint; lateral
+areas convergent in the middle; striae indistinct, about 25 in 10 [mu]. L.
+23 [mu].
+
+Brandywine Creek (Palmer).
+
+Pl. 27, Fig. 23.
+
+
+DECUSSATAE CL.
+
+Valve elliptical or lanceolate; axial area narrow; central area small;
+striae punctate, in transverse and oblique, curved rows.
+
+
+NAVICULA PLACENTA EHR.
+
+Valve elliptical, with short, rostrate-capitate ends; axial area narrow;
+central area elliptical; striae in two directions, the transverse about 22
+(to 27, Cl.) in 10 [mu], the oblique striae crossing in both directions in
+curved lines appearing "coarser than the transverse" (Lewis).
+
+A very peculiar species which, as Cleve remarks, seems not to be allied to
+any other. L. about 35 [mu], quite constant in size. It is reported from
+Finland, Scotland, Hungary and New Zealand. Dr. Lewis found it in the
+Delaware River. It is occasional in the Schuylkill River and the blue clay,
+and very abundant on Marchantia and mosses on the wet rocks of the upper
+Wissahickon (F. J. Keeley).
+
+Pl. 27, Fig. 17.
+
+
+LINEOLATAE CL.
+
+Valve more or less lanceolate; axial area narrow or indistinct; striae
+radiate or parallel, lineate, that is, with the puncta closer than the
+striae.
+
+
+NAVICULA RADIOSA KUETZ.
+
+Valve lanceolate with sub-rostrate apices; axial area indistinct; central
+area small; striae radiate in the middle, from 6 to 8 in 10 [mu], and
+convergent at the ends, about 12 in 10 [mu]. L. 47 [mu].
+
+Very common in fresh water.
+
+Pl. 26, Fig. 17; Pl. 40, Fig. 9.
+
+
+NAVICULA PEREGRINA EHR.
+
+Valve lanceolate, obtuse; axial area narrow; central area large, rounded or
+slightly irregular; striae coarse in the middle, 5 in 10 [mu], radiate;
+convergent at the ends, 7 or 8 in 10 [mu].
+
+Abundant in brackish water. Delaware River.
+
+Pl. 26, Fig. 20.
+
+
+{95}NAVICULA CYPRINUS (WM. SM.)
+
+Valve lanceolate, slightly gibbous in the middle, sub-cuneate at the ends;
+axial area narrow; central area small; striae radiate in the middle, 10 in
+10 [mu], with shorter, transverse striae intermediate; transverse at the
+extreme ends. L. 82 [mu].
+
+_Navicula digito-radiata_ var. _cyprinus_ (Ehr. ?) Wm. Sm. Whether the form
+here figured is Ehrenberg's or not, it is the species known as Pinnularia
+cyprinus Ehr. of Wm. Smith.
+
+Common in Shark River, N. J.
+
+Pl. 26, Fig. 21.
+
+
+NAVICULA REINHARDTII GRUN.
+
+Valve elliptical or elliptical-lanceolate, with broad, rounded ends; axial
+area narrow, widened at the ends to the width of the valve; central area
+widened transversely to an irregular, quadrate space; striae coarse, 8 in
+10 [mu], distinctly lineate, alternately longer and shorter in the middle,
+radiate, nearly transverse at the ends. L. 59 [mu].
+
+Blue clay. Rare.
+
+Pl. 26, Fig. 22.
+
+
+NAVICULA LANCEOLATA VAR. ARENARIA (DONK.) CL.
+
+Valve lanceolate; axial area very narrow or indistinct; central area small,
+rounded; striae radiate, 11 in 10 [mu] in the middle, closer at the ends.
+L. 47-54 [mu].
+
+_Navicula arenaria_ Donk.
+
+Shark River, N. J.
+
+Pl. 26, Fig. 23.
+
+
+NAVICULA SALINARUM GRUN.
+
+Valve elliptical-lanceolate with produced sub-capitate or rostrate ends;
+striae radiate in the middle, longer and shorter; transverse at the ends,
+lineate. L. 32 [mu].
+
+Atlantic City, N. J.
+
+Pl. 26, Fig. 24.
+
+
+NAVICULA VIRIDULA VAR. ROSTELLATA KUETZ.
+
+Valve lanceolate with rostrate ends; axial area very narrow, central area
+orbicular; striae radiate in the middle, about 12 in 10 [mu], convergent at
+the ends and closer. L. 43 [mu].
+
+Common in fresh water.
+
+Pl. 26, Fig. 16.
+
+
+NAVICULA GRACILIS VAR. SCHIZONEMOIDES (EHR.) V. H.
+
+Valve lanceolate, obtuse; axial area widened in the middle; striae radiate
+in the middle, about 12 in 10 [mu], transverse or slightly convergent at
+the ends. L. 45-60 [mu]. Occurs in gelatinous tubes; usually found free.
+
+_Colletonema neglectum_ Thwaites.
+
+Fresh water.
+
+Pl. 26, Fig. 19.
+
+
+NAVICULA RAMOSISSIMA (AG.) CL.
+
+Valve lanceolate, sub-acute; axial area very narrow; central area scarcely
+widened; striae, 12 in 10 [mu], parallel throughout. L. 45 [mu].
+
+_Micromega ramosissimum_ Ag.
+
+_Schizonema smithii_ Kuetz. (not Ag.).
+
+East River, N. Y.
+
+Pl. 26, Fig. 14.
+
+
+{96}NAVICULA ANGLICA RALFS
+
+Valve elliptical, with sub-capitate or rostrate ends; axial area narrow,
+central area small; striae radiate, 12-13 in 10 [mu], distinctly punctate.
+L. 26 [mu].
+
+Fresh water.
+
+Pl. 26, Fig. 26.
+
+
+NAVICULA GASTRUM EHR.
+
+Valve elliptical, with rostrate ends; axial area narrow, central area
+transverse or irregular; striae radiate, 9 in 10 [mu] in the middle. L. 26
+[mu].
+
+The form here figured approaches N. anglica.
+
+Kirkwood Pond, N. J.
+
+Pl. 26, Fig. 25.
+
+
+NAVICULA DICEPHALA WM. SM.
+
+Valve linear, with rostrate or rostrate-capitate ends; axial area narrow,
+central area rectangular, transverse; striae radiate, 12 in 10 [mu]. L. 32
+[mu].
+
+Fresh water.
+
+Pl. 27, Fig. 16.
+
+
+NAVICULA HUMILIS DONK.
+
+Valve elliptical, with broad, rostrate ends; axial area narrow; central
+area small; striae radiate and distant in the middle, convergent at the
+ends, coarse, appearing costate, averaging 9 in 10 [mu]. L. 19 [mu]. As
+Donkin states, the striae are "very conspicuous."
+
+_Navicula hungarica_ var. _capitata_ (Ehr.) Cl.
+
+_Navicula globiceps_ Lagerstedt, according to Cleve.
+
+Willistown, Pa.
+
+Pl. 27, Fig. 24.
+
+
+NAVICULA PINNATA PANT. ?
+
+Valve lanceolate, obtuse; axial area narrow, widened in the middle; striae
+coarse, 7 in 10 [mu] in the middle, radiate, 10 in 10 [mu] at the ends and
+transverse, indistinctly lineate. L. 40 [mu].
+
+Near _Navicula ardua_ Mann (Diat. Albatross Voy., Cont. U. S. Nat.
+Herbarium Vol. 10, Part 5, p. 336, Pl. 53, Fig. 2) which, however, is said
+to have "strictly unbeaded costae."
+
+Pavonia, N. J., artesian well.
+
+Pl. 27, Fig. 20.
+
+
+NAVICULA PENNATA A. S.
+
+Valve lanceolate, acute; axial area narrow; central area quadrate,
+transverse; striae radiate, coarse, 5 in 10 [mu], lineate. L. 68-95 [mu]
+(Cleve).
+
+Pavonia, N. J., artesian well.
+
+Pl. 27, Fig. 22.
+
+
+NAVICULA INFLEXA GREG.
+
+Valve slightly elliptical-lanceolate, sub-acute, smooth at the ends; axial
+area narrow, widened in the middle; striae radiate, 11 in 10 [mu], lineate.
+Frustule in zone view constricted in the middle. L. 28-45 [mu].
+
+Common along the coast.
+
+Pl. 27, Figs. 18 and 19.
+
+
+{97}NAVICULA OBLONGA KUETZ.
+
+Valve linear-lanceolate, with broad, rounded ends; margin sometimes
+undulate; axial area narrow; central area large, orbicular; striae in the
+middle distant, radiate, convergent at the ends and curved or sharply bent,
+7 in 10 [mu], lineate. L. 70-200 [mu] (Cleve).
+
+Blue clay. Occasional in fresh water.
+
+Pl. 27, Fig. 21.
+
+
+NAVICULA HASTA PANT.
+
+Valve lanceolate, gently tapering to the obtuse, produced ends; axial area
+lanceolate, widened to an orbicular space in the middle; striae radiate,
+the median coarse and quite distant, 5 in 10 [mu], becoming closer at the
+ends where they are 12 in 10 [mu], lineate. The distance between the median
+striae gives the appearance of a stauros.
+
+Occasional in the blue clay.
+
+Pl. 27, Fig. 13.
+
+
+NAVICULA HASTA VAR. PUNCTATA N. VAR.
+
+Valve as in type but with striae in the middle distinctly punctate and
+reaching the median line.
+
+Greenwich Point, Philadelphia.
+
+Pl. 27, Fig. 14.
+
+
+NAVICULA RHYNCOCEPHALA KUETZ.
+
+Valve lanceolate, with produced ends; axial area indistinct; central area
+small, rounded; striae radiate in the middle, convergent at the ends, 10-11
+in 10 [mu], punctate. L. 42 [mu].
+
+Fresh water. Common.
+
+Pl. 31, Fig. 8.
+
+
+NAVICULA CRYPTOCEPHALA KUETZ.
+
+Valve lanceolate, with rostrate ends; axial area indistinct; central area
+small; striae, 16 in 10 [mu], lineate, radiate in the middle, convergent at
+the ends. L. 28 [mu].
+
+Common in fresh water.
+
+Intermediate forms occur between N. rhyncocephala and N. cryptocephala.
+
+Pl. 31, Fig. 9.
+
+
+NAVICULA LONGA (GREG.) RALFS
+
+Valve slender, rhombic, elongated, with acute ends; axial area indistinct;
+central area small; striae, 6 or 7 in 10 [mu], radiate in the middle,
+elsewhere transverse; central pores closely approximate. L. 120 [mu].
+
+New Rochelle, N. Y.
+
+Pl. 31, Fig. 10.
+
+Cleve refers this form to N. directa var. remota Grun. Some specimens are
+found in this locality showing the "generally twisted" median line
+mentioned by Gregory.
+
+
+MESOLEIAE CL.
+
+Valve linear or elliptical; axial area narrow; central area quadrate;
+striae radiate, finely punctate.
+
+
+NAVICULA MUTICA KUETZ.
+
+Valve ovate, elliptical or lanceolate; axial area narrow; central area
+dilated into a stauros not reaching the margin; striae about 20 in 10 [mu],
+more distant in the middle, radiate, punctate. A punctum occurs on one side
+of the central nodule.
+
+{98}Reported from New Jersey in fresh water. I have not found it. The
+figure is from a specimen from another locality.
+
+Pl. 26, Fig. 6.
+
+
+NAVICULA MINIMA GRUN.
+
+Valve broadly elliptical, 13-15 [mu] in length; axial area narrow; central
+area small but with a quadrate pseudo-stauros which is striated; striae,
+about 28 in 10 [mu], radiate.
+
+Agrees closely with N. saugeri var. Grun. in V. H. Synopsis, Pl. 14, Fig.
+16, said to be intermediate between N. minima and N. atomoides Grun. N.
+minima var. atomoides Grun. is smaller.
+
+Common in water-troughs.
+
+Pl. 26, Fig. 13.
+
+
+NAVICULA PUPULA VAR. BACILLARIOIDES GRUN.
+
+Valve linear, with rounded ends; axial area linear, expanding on both sides
+near the ends of the valve, forming a transverse lunate space; central area
+small, apparently expanded into a stauros, which, however, is striated;
+striae, 18 in 10 [mu], at the middle, closer at the ends, punctate. L. 54
+[mu].
+
+Pavonia, N. J., artesian well.
+
+Pl. 26, Fig. 9.
+
+
+BACILLARES CL.
+
+Valve linear or linear-elliptical, with broad ends; axial area narrow, the
+median line enclosed in siliceous ribs; striae finely punctate, more
+distant in the middle.
+
+
+NAVICULA BACILLUM EHR.
+
+Valve linear, with rounded ends; axial area enclosed in siliceous ribs and
+slightly expanded on each side at the ends; terminal nodules incrassate;
+central area small, elliptical; striae, 15 in 10 [mu] in the middle,
+transverse, distinctly punctate, closer at the ends L. 47 [mu].
+
+Fresh water.
+
+Pl. 26, Fig. 10.
+
+Cleve describes the form as having slightly radiate striae in the middle.
+There is considerable difference in the descriptions of Cleve, Donkin,
+Grunow and Van Heurck, as also in all of the figures.
+
+
+NAVICULA AMERICANA EHR.
+
+Valve oblong-linear, with rounded ends, sometimes slightly constricted;
+axial area about one-half the width of the valve, dilated in the middle;
+striae parallel in the middle, radiate at the ends, 15-16 in 10 [mu]. A
+punctum is usually found in the central nodule. L. 55-154 [mu].
+
+Blue clay. Occasional in fresh water.
+
+Pl. 26, Fig. 8.
+
+
+DECIPIENTES CL.
+
+Valve lanceolate, with obtuse ends; axial area narrow; central area
+orbicular; striae radiate in the middle and more distant.
+
+
+NAVICULA SEMEN EHR.
+
+Valve elliptic-lanceolate, with sub-rostrate, truncate apices; axial area
+narrow, {99}sinuous; central area orbicular; terminal fissures small,
+hook-shaped; striae robust, 7 or 8 in the middle, closer at the ends,
+indistinctly punctate or lineolate.
+
+Blue clay. Not common.
+
+Pl. 26, Fig. 11.
+
+Cleve states that this form belongs to the post-glacial deposits and is
+found living only in the Hartz Mountains.
+
+
+NAVICULA INTEGRA WM. SM.
+
+Valve lanceolate with triundulate margins and rostrate-apiculate ends;
+striae radiate, more distant in the middle, 20-23 in [mu], punctate; axial
+area very narrow, central area rounded or elliptical. L. 33-43 [mu].
+
+Pavonia, N. J., artesian well. Common in Chester River, Md.
+
+Pl. 26, Fig. 5.
+
+
+MICROSTIGMATICAE CL.
+
+Valve lanceolate; axial area narrow; central area small, rounded; striae
+finely punctate, nearly parallel. (Includes here only the division
+Libellus.)
+
+
+NAVICULA TUMIDA (BREB.) CL.
+
+Valve lanceolate, with rounded ends; axial area narrow, central area
+elliptical; raphe slightly sigmoid; striae, 13 in 10 [mu], finely punctate,
+a few shorter in the middle.
+
+_Scoliopleura tumida_ (Breb.) V. H.
+
+Cape May, N. J.
+
+Pl. 25, Fig. 1.
+
+
+NAVICULA GREVILLEI (AG.) CL.
+
+Frustules in gelatinous tubes, rectangular; zone with numerous longitudinal
+divisions. Valve elliptical-lanceolate, obtuse; axial area narrow, central
+area small; striae lineate, about 18 in 10 [mu] in the middle where they
+are slightly radiate and more evident, closer near the ends and transverse;
+median line with terminal pores distant from the ends. L. 60 [mu].
+
+_Schizonema grevillei_ Ag.
+
+East River, N. Y.
+
+Pl. 31, Figs. 3 and 4.
+
+
+NAVICULA LIBELLUS GREG.
+
+Valve rhombic-elliptical, obtuse at the ends; axial area narrow, central
+rounded, small; striae punctate, slightly radiate, about 19 in 10 [mu];
+terminal fissures close to the ends, indistinct. L. 60 [mu].
+
+Cleve describes this form as having acute ends, while Gregory states that
+it is "more obtuse and broader than N. rhombica." Gregory's Figure 101
+apparently shows the ends acute, but he says that the valve view is
+"rhombic or elliptic-lanceolate, broad, with obtuse ends" (Diat. of the
+Clyde, p. 57, Pl. 6).
+
+Hackensack Swamp, N. J.
+
+Pl. 31, Fig. 5.
+
+
+ORTHOSTICHAE CL.
+
+Valve lanceolate or elongated; axial area narrow; central area sometimes
+apparently dilated into a stauros; striae punctate, the puncta in
+transverse and longitudinal rows.
+
+
+{100}NAVICULA CUSPIDATA KUETZ.
+
+Valve rhombic-lanceolate, with acute ends; axial area linear, narrow, not
+widened in the middle; striae transverse, 14-19 in 10 [mu] (Cl.). L. 70-150
+[mu].
+
+Blue clay. Not uncommon in fresh water.
+
+Pl. 26, Figs. 1 and 2.
+
+Fig. 2 represents an inner valve or stratum, with strong costae variable in
+size, formerly known as Surirella craticula Ehr.
+
+_N. cuspidata var. ambigua (Ehr.) Cl._--Valve elliptical-lanceolate, with
+rostrate ends, smaller than the type and with finer striae.
+
+Crum Creek.
+
+Pl. 26, Fig. 3.
+
+
+NAVICULA SPICULA (HICKIE) CL.
+
+Valve narrow, lanceolate with acute ends; axial area narrow, central area
+dilated into a stauros reaching the margin; transverse striae, 25-29 in 10
+[mu], longitudinal closer. L. 50-130 (Cl.).
+
+Sometimes confused with N. crucigera.
+
+_Stauroneis spicula_ Hickie.
+
+Newark, N. J.
+
+Pl. 26, Fig. 4.
+
+
+NAVICULA CRUCIGERA (WM. SM.) CL.
+
+Valve lanceolate, narrow, with acute apices; central nodule a stauros
+reaching the margin but crossed by two or three coarser striae; transverse
+striae, 12 in 10 [mu], punctate, the puncta about 25 in 10 [mu]. L. 80-100
+[mu] (Cl.). Frustules in gelatinous tubes or free.
+
+_Schizonema cruciger_ Wm. Sm.
+
+Pl. 26, Fig. 15.
+
+Reported as occurring in New York Bay, but I have not seen it. The figure
+is from a specimen from another locality.
+
+
+MINUSCULAE CL.
+
+Valve lanceolate or elliptical, chiefly distinguished by the small size;
+axial area indistinct; central area small; striae radiate, very finely
+punctate.
+
+
+NAVICULA ATOMUS NAEGELI
+
+Valve elliptical, 6-8 [mu] in length; striae radiate, 26-30 [mu], closer
+near the ends; axial area linear, scarcely widened in the middle.
+
+Water-troughs and ditches. Probably common, but frequently not noticed
+because of its minuteness. A mounting medium of the highest refractive
+index, such as realgar, is required to resolve the striae. In the figure
+the striae are drawn a little coarser than they appear in most specimens.
+
+Pl. 26, Fig. 12.
+
+
+LAEVISTRIATAE CL.
+
+Valve lanceolate, axial area distinct; central area orbicular; striae
+coarse, indistinctly punctate, approaching the costae of Pinnularia.
+
+
+{101}NAVICULA YARRENSIS GRUN.
+
+Valve elliptical-lanceolate, with rounded ends; axial area lanceolate,
+widened in the middle; striae, 5 in 10 [mu]. L. 97 [mu].
+
+Cape May, N. J. Common.
+
+Pl. 25, Fig. 14.
+
+Fig. 15, a smaller form, 65 [mu] in length; striae, 6 in 10 [mu].
+
+Fig. 16, 54 [mu] in length; striae, 8 in 10 [mu] (near var. valida Pant.).
+
+
+NAVICULA ELEGANS WM. SM.
+
+Valve elliptical-lanceolate, with produced ends; axial area very narrow,
+central area large, orbicular; striae strongly divergent in the middle,
+slightly, if at all, convergent at the ends, curved toward the margin,
+indistinctly lineate, 9 in 10 [mu]. L. 95 [mu].
+
+Blue clay. Not rare.
+
+Pl. 31, Fig. 1.
+
+_Navicula elegans var. cuspidata Cl._--Valve as in type form but smaller
+and with rostrate apices; striae, 10 in 10 [mu]. L. 82 [mu].
+
+Belmar, N. J.
+
+Pl. 31, Fig. 2.
+
+Cleve remarks that the type form is acute and the striae 9, while the var.
+cuspidata has 12 striae in 10 [mu]. In Fig. 1, Pl. 31, is represented a
+valve having 9 striae in 10 [mu], but not acute, while Fig. 2, with but
+slight variation in striae, is more cuspidate. It is probable there are
+intermediate variations.
+
+
+NAVICULA PALPEBRALIS BREB.
+
+Valve elliptical-lanceolate, with acute apiculate ends; axial area broad,
+lanceolate; striae radiate, lineate, about 11 in 10 [mu]. L. 60 [mu].
+
+Along the coast.
+
+Pl. 31, Figs. 6 and 7.
+
+On Plate 40, Fig. 5, is represented an abnormal form of Navicula in which
+the central pores are in a line transverse to the longitudinal axis and
+each raphe is curved in a line which almost returns to the centre. The
+puncta are in curved lines radiating from the rounded hyaline centre.
+
+Pavonia, N. J., artesian well.
+
+Weissflog has described valves of Navicula somewhat similar in punctation.
+
+
+PINNULARIA EHR. (1843)
+
+(pinnula, a small feather)
+
+Valve linear or nearly so, with rounded ends; axial area broad; central and
+terminal areas large; costae smooth, transverse or radiating, usually
+convergent at the ends.
+
+The costae are channels on the inside of the valve, closed, except in the
+middle where elliptical foramina, opening into the interior of the valve,
+give rise through their terminal margins to the two longitudinal lines on
+each side of the valve. The raphe begins as a groove in the side of the
+conical central nodule and continues as a cleft at right angles to the
+plane of the surface of the valve, in which case the raphe forms a single
+line; if the raphe is inclined to the valve surface, then two lines appear
+in projection, the upper and lower edges of the cleft. In some forms the
+surface of the edge of the raphe on one side is folded or grooved for a
+considerable distance, and the opposite edge is elevated into a ridge or
+{102}tongue fitting into the groove. In such cases it is possible, in
+projection, to see the upper or outer edges of the raphe, the lower edges
+and the edges of the tongue and groove, thus showing four lines; sometimes,
+when the tongue and groove do not meet, six lines. The so-called inner
+channel is the part of the raphe on the inside of the tongue, and the
+so-called exterior channel is the part of the raphe on the outside of the
+tongue. If, in addition to this formation of the raphe, the plane of
+cleavage changes toward the terminal nodules, the lines will cross each
+other and, when two are superimposed, disappear altogether. For the careful
+examination of the raphe it is necessary to employ large forms, and it is
+advisable to use nitrate of silver which remains in the raphe, and, as in
+slides mounted by Mr. F. J. Keeley, shows in a beautiful manner the entire
+outline of raphe and fissures. The terminal fissures owe their separation
+to the different directions taken by the two edges of the raphe on each
+side, one edge bending in a wide curve toward the end of the valve, showing
+two lines, the upper and lower edges of one side of the raphe when inclined
+to the plane of the surface, and the other edge of the raphe turning
+suddenly in an opposite direction and ending abruptly in a curve, giving
+rise to the appearance, by diffraction, of a punctum.
+
+Pl. 40, Figs. 13, 14 and 15.
+
+Endochrome consists of two chromatophores lying on the zones.
+
+Pinnularia is usually divided into the Majores, or larger, and the Minores,
+or smaller forms, the latter being further divided according to their
+striae. The following classification is chiefly that of Cleve.
+
+_Majores._--Valve large, linear with parallel or slightly radiate striae
+and broad axial area.
+
+_Gracillimae._--Valve small, striae parallel or nearly so; axial area very
+narrow.
+
+_Capitatae._--Valve with capitate or rostrate ends; striae radiate.
+
+_Divergentes._--Striae strongly radiate.
+
+_Brevistriatae._--Striae short.
+
+_Distantes._--Striae distant.
+
+_Tabellariae._--Striae radiate in the middle, strongly convergent at the
+ends.
+
+_Marinae._--Marine forms.
+
+
+MAJORES
+
+PINNULARIA MAJOR (KUETZ.) WM. SM.
+
+Valve linear, usually slightly gibbous in the middle and at the ends; raphe
+oblique; axial area less than one-third the width of valve, convergent at
+the ends; striae, 7 or 8 in 10 [mu], radiate in the middle, convergent at
+the ends, crossed by a narrow band. L. ? to 300 [mu].
+
+Blue clay. Fresh water. Abundant at Middletown, Delaware Co. (T. C.
+Palmer).
+
+Pl. 28, Fig. 4.
+
+Fig. 9, Pl. 29, is one of a number of smaller forms which are difficult to
+determine, approaching P. viridis.
+
+
+PINNULARIA MAJOR VAR. PULCHELLA N. VAR.
+
+Valve strongly gibbous in the middle and gradually widened to the rounded
+ends; axial area broad, less than one-third the width of the valve, widened
+unilaterally in the middle; striae, 7 in 10 [mu], crossed by a band nearly
+as wide as the length of the costae and scarcely distinct. L. 273 [mu].
+
+{103}The central nodule is scarcely evident, probably because it is not so
+thick as in other forms. The outline is near to that of N. mesogongyla and
+certain forms of N. nobilis, differing from the latter in the median line,
+striae and band which is wider than that of P. latevittata var. domingensis
+Cl.
+
+Hammonton Pond, N. J.
+
+Pl. 28, Fig. 2.
+
+A very beautiful form which I cannot find described or figured. It does not
+appear to be N. major var. turgidula Cl., which has a narrow band. In the
+fossil deposit from Hopkinton, N. H., valves occur similar in outline but
+smaller.
+
+
+PINNULARIA NOBILIS EHR.
+
+Valve slightly gibbous in the middle and at the ends; median line complex;
+striae, 4 or 5 in 10 [mu], slightly convergent or parallel at the ends,
+crossed by a band one-third as wide as the length of the striae. L. ? to
+350 [mu].
+
+Blue clay. Fresh water.
+
+Pl. 28, Fig. 1.
+
+
+PINNULARIA DACTYLUS EHR.
+
+Valve broad, linear, slightly gibbous in the middle; ends broad, rounded;
+median line not complex, sinuous; striae, 4 or 5 in 10 [mu], crossed by a
+very broad band. L. ? to 300 [mu].
+
+_Navicula gigas_ A. S.
+
+Blue clay. Fresh water.
+
+Pl. 28, Fig. 3.
+
+Forms occur which are with difficulty assigned to either nobilis or
+dactylus.
+
+
+PINNULARIA DACTYLUS VAR. DARIANA (A. S.) CL.
+
+Valve linear-lanceolate, obtuse; axial area broad, less than one-third the
+width of the valve; striae, 6 in 10 [mu], crossed by a broad band. L. 220
+[mu].
+
+Absecon, N. J.
+
+Pl. 29, Fig. 3.
+
+
+PINNULARIA DACTYLUS VAR. DEMERARAE CL.
+
+Valve elliptical-lanceolate, with sub-cuneate ends; axial area lanceolate,
+broad in the middle; median line flexuose; striae radiate throughout, 6 in
+10 [mu]. L. 150 [mu].
+
+Blue clay.
+
+Pl. 29, Fig. 10.
+
+
+PINNULARIA GENTILIS (DONK.) CL.
+
+Valve linear, with rounded ends; axial area about one-fourth the diameter
+of the valve; striae radiate in the middle, convergent at the ends, 7 in 10
+[mu], crossed by a broad indistinct band.
+
+Fresh water. Not common.
+
+Pl. 29, Fig. 1.
+
+
+PINNULARIA TRIGONOCEPHALA CL.
+
+Valve linear, gibbous in the middle and at the cuneate ends; axial area
+wider between the middle and the ends, dilated to an elliptical space in
+the middle; striae, 6 in 10 [mu]. L. 145 [mu].
+
+Blue clay.
+
+Pl. 29, Fig. 8.
+
+
+{104}PINNULARIA VIRIDIS NITZSCH
+
+Valve linear-elliptical, with rounded ends; axial area narrow, widened in
+the middle; striae, 6 to 7 in 10 [mu], crossed by a band as wide as
+one-third the length of the striae.
+
+Common in fresh water.
+
+Pl. 29, Fig. 2.
+
+Quite variable in size. Approaches P. major by intermediate forms as in
+Fig. 9, Pl. 29.
+
+
+PINNULARIA VIRIDIS VAR. FALLAX CL.
+
+Valve linear, with rounded ends; axial area narrow, slightly widened in the
+middle; striae sometimes unilaterally interrupted, nearly parallel, 10 in
+10 [mu].
+
+Elm, N. J.
+
+Pl. 29, Fig. 4.
+
+In Fig. 2, Pl. 30, a form is represented which corresponds closely to
+Navicula viridis var. B, of Wm. Smith. It is given as synonymous with var.
+fallax; it is bilaterally interrupted. Blue clay.
+
+
+PINNULARIA VIRIDIS VAR. ?
+
+Valve linear-elliptical, with rounded ends; axial area narrow, widened in
+the middle to a transverse fascia which is sometimes unilateral; striae,
+14, in the middle, divergent, convergent at the ends and closer, crossed by
+a narrow band. L. 45-60 [mu]. Fascia sometimes absent or very narrow.
+
+Northbrook, Pa.
+
+Pl. 30, Fig. 17 (represents a form with wider area than usual).
+
+
+PINNULARIA VIRIDIS VAR. CAUDATA N. VAR.
+
+Valve elliptical-lanceolate, with sub-rostrate ends; axial area narrow,
+widened to an orbicular space in the middle; striae radiate in the middle,
+11-12 in 10 [mu], convergent and closer at the ends, crossed by a narrow
+band; median line with very long terminal fissures; terminal nodules
+noticeable because of the thickening of the edges of the terminal striae.
+L. 43 [mu].
+
+Fresh water, Newtown Square. Not common.
+
+Pl. 30, Fig. 18.
+
+
+PINNULARIA SOCIALIS (PALMER)
+
+Valve linear, with rounded ends; axial area broad, one-third the width of
+the valve; striae slightly radiate in the middle, convergent at the ends,
+elsewhere parallel, 8 in 10 [mu], crossed by an indistinct band about
+one-third the length of the striae. L. 60-120 [mu].
+
+This species, discovered by Mr. Palmer near Media, Pa., is remarkable for
+the grouping of the frustules "held with girdle sides together by a
+siliceous cementing of valve edges and enclosed in a common coleoderm." The
+usual number included in a group is four, but sometimes six or eight are
+noticed. The frustules adhere near their ends and are so firmly fastened
+that boiling in nitric acid and bichromate of potash for fifteen minutes
+will not separate them.
+
+_Navicula socialis_ Palmer (Proc. Acad. Nat. Sci., Phila., 1910, p. 460,
+Pl. 35).
+
+Media, Pa.
+
+Pl. 29, Fig. 5.
+
+
+{105}PINNULARIA AESTUARII CL.
+
+Valve linear, with rounded ends; axial area broad, less than one-third the
+width of the valve; central area a transverse fascia; striae, 7 in 10 [mu],
+parallel except at the ends where they are slightly convergent; median line
+flexuose, with short, terminal semicircular fissures. L. 85 [mu].
+
+Port Penn, Delaware River. Rare.
+
+Pl. 29, Fig. 6.
+
+
+GRACILLIMAE
+
+PINNULARIA MOLARIS (GRUN.) CL.
+
+Valve very convex, linear, with sub-cuneate ends; axial area narrow,
+expanded in the middle to a transverse fascia reaching the margin; striae
+divergent in the middle, convergent at the ends, 16 in 10 [mu]. L. 60 [mu].
+
+Fresh water.
+
+Pl. 29, Fig. 15.
+
+
+PINNULARIA LEPTOSOMA GRUN.
+
+Valve linear, rounded at the ends; axial area narrow; central area a broad
+transverse fascia; striae slightly divergent in the middle and convergent
+at the ends, 17 in 10 [mu] in the middle, closer at the ends. L. 56 [mu].
+
+Fresh water. Not common.
+
+Pl. 30, Fig. 10.
+
+
+CAPITATAE
+
+PINNULARIA MESOLEPTA EHR.
+
+Valve linear, with triundulate margins and capitate ends; axial area
+narrow, widened in the middle; striae divergent in the middle, convergent
+at the ends, about 12 in 10 [mu]. L. 34 [mu].
+
+Common in fresh water.
+
+Pl. 29, Fig. 13.
+
+
+PINNULARIA MESOLEPTA VAR. STAURONEIFORMIS GRUN.
+
+Valve triundulate, capitate; axial area narrow, widened in the middle to a
+transverse fascia, broader at the margin; striae strongly divergent in the
+middle and convergent at the ends, 9-10 in 10 [mu]. L. 70 [mu].
+
+Pavonia, N. J., artesian well. Fresh water.
+
+Pl. 30, Fig. 20.
+
+
+PINNULARIA SUBCAPITATA GREG.
+
+Valve linear or linear-elliptical, with sub-capitate ends; axial area
+distinct, widened to a transverse fascia in the middle; striae divergent in
+the middle, convergent at the ends, 13 in 10 [mu]. L. 32 [mu].
+
+Fresh water.
+
+Pl. 29, Fig. 20.
+
+
+{106}PINNULARIA SUBCAPITATA VAR. PAUCISTRIATA GRUN.
+
+Valve linear-elliptical, with rounded ends; axial area gradually widened
+into a broad, transverse fascia; striae divergent in the middle, convergent
+at the ends, 11-12 in 10 [mu]. L. 47 [mu].
+
+Fresh water.
+
+Pl. 30, Fig. 16.
+
+
+PINNULARIA TERMES (EHR.) A. S.
+
+Valve linear, with concave margins and rostrate-capitate ends; axial area
+narrow, widened in the middle to an orbicular or sub-quadrate space; striae
+divergent in the middle, scarcely, if at all, convergent at the ends, 10 in
+10 [mu].
+
+Pensauken, N. J., artesian well.
+
+Pl. 29, Fig. 17.
+
+This is, I believe, the form figured by Schmidt (Atlas, Pl. 45, Fig. 67).
+Cleve refers it to Pinnularia interrupta forma biceps, in which the central
+space is rhomboid.
+
+
+PINNULARIA TERMES VAR. STAURONEIFORMIS V. H.
+
+Valve linear, with concave margins and capitate-rostrate ends; axial area
+narrow, widened into a rhomboidal fascia, reaching the margin; striae, 10
+in 10 [mu], divergent in the middle, convergent at the ends.
+
+_Pinnularia interrupta forma stauroneiformis_ Cl.
+
+Fresh water.
+
+Pl. 29, Fig. 14.
+
+
+PINNULARIA APPENDICULATA (AG.) CL.
+
+Valve linear, with subcapitate ends; axial area narrow; central area a
+transverse fascia; striae divergent in the middle, convergent at the ends,
+16 in 10 [mu]. L. 43 [mu].
+
+Fresh water. Marl pits, Lenola, N. J. (Palmer).
+
+Pl. 29, Fig. 18.
+
+
+PINNULARIA BRAUNII GRUN.
+
+Valve linear-lanceolate, with capitate ends; axial area gradually widened
+toward the middle and expanded into a fascia reaching the margin; striae
+divergent in the middle, convergent at the ends, 11 in 10 [mu]. L. 52 [mu].
+
+Pensauken, N. J., artesian well.
+
+Pl. 29, Fig. 16.
+
+
+PINNULARIA MICROSTAURON (EHR.) CL.
+
+Valve convex, linear, tapering to sub-cuneate or sub-rostrate ends; axial
+area very narrow; central area a broad fascia; striae divergent in the
+middle, convergent at the ends, 12 in 10 [mu]. L. 35 [mu].
+
+Pavonia, N. J., artesian well.
+
+Pl. 29, Fig. 19.
+
+This form does not exactly correspond to Cleve's diagnosis, as the ends are
+not broad. All species in the group Capitatae are quite variable.
+
+
+{107}DIVERGENTES
+
+PINNULARIA DIVERGENS VAR. ELLIPTICA GRUN.
+
+Valve linear, with rounded ends; axial area widened in the middle to a
+transverse fascia; striae, 9 in 10 [mu], divergent in the middle,
+convergent at the ends. L. 150 [mu].
+
+Fresh water. Not common in this locality.
+
+Pl. 31, Fig. 13.
+
+
+PINNULARIA CARDINALICULUS CL.
+
+Valve linear, with rounded ends; axial area wide, less than one-third the
+width of the valve, expanded to a transverse fascia; striae divergent in
+the middle and slightly convergent at the ends, 9 in 10 [mu]. L. 97 [mu].
+
+Blue clay.
+
+Pl. 30, Fig. 1.
+
+As a rule, the median fissures in Pinnularia are turned inwards on the side
+of the longer edge of the terminal fissures, but not always. In this
+specimen the median fissures are turned slightly toward the side of the
+shorter edge of the terminal fissures.
+
+
+PINNULARIA LEGUMEN EHR.
+
+Valve linear, with more or less triundulate margins and broad, capitate
+ends; axial area less than one-fourth the width of valve, widened in the
+middle; striae strongly divergent in the middle and convergent at the ends,
+10 in 10 [mu]. L. 84 [mu].
+
+Fresh water. May's Landing, N. J.
+
+Pl. 30, Fig. 3.
+
+
+PINNULARIA LEGUMEN VAR. ?
+
+Valve as in type, but with a transverse fascia; striae, 10 in 10 [mu],
+curved or bent near the ends. L. 84 [mu].
+
+This form is not var. florentina Grun.
+
+May's Landing, N. J. (with the type).
+
+Pl. 30, Fig. 4.
+
+
+PINNULARIA BREBISSONII (KUETZ.) CL.
+
+Valve linear-elliptical, with rounded ends; axial area narrow, widened into
+a transverse fascia which is usually broader at the ends; striae divergent
+in the middle, convergent at the ends, about 12 in 10 [mu]. L. 40-60 [mu]
+(Cl.).
+
+Fresh water. Common.
+
+Pl. 29, Fig. 12; Pl. 31, Fig. 11.
+
+Variable in outline.
+
+
+PINNULARIA MORMONORUM (GRUN.)
+
+Valve linear, with rounded ends; striae divergent in the middle, convergent
+at the ends, 10 in 10 [mu]; axial area rhombic-lanceolate, widened to a
+fascia usually reaching the border. L. 62 [mu].
+
+_Navicula mormonorum_ Grun.
+
+Common near Willistown, Pa.
+
+This form is regarded by Cleve as P. brebissonii, but the axial area
+appears to distinguish it. The valves are sometimes narrowed in the middle.
+
+Pl. 29, Fig. 11.
+
+
+{108}BREVISTRIATAE
+
+PINNULARIA ACROSPHAERIA (BREB.) CL.
+
+Valve linear, gibbous in the middle and at the ends; axial area about half
+the width of the valve; median line with approximate central pores; median
+area punctate; striae nearly parallel, radiate at the ends, 9 in 10 [mu].
+L. 32-180 [mu] (Cl.).
+
+Blue clay. Recent, fresh water.
+
+Pl. 30, Fig. 7.
+
+
+PINNULARIA ACROSPHAERIA VAR. TURGIDULA GRUN. ?
+
+Valve strongly gibbous in the middle; ends rounded; striae, 12-13 in 10
+[mu]. L. 54 [mu].
+
+Blue clay, Gloucester, N. J., artesian well.
+
+Pl. 30, Fig. 8.
+
+
+PINNULARIA BLANDITA N. SP.
+
+Valve linear, gibbous in the middle, and with rounded ends; striae radiate
+in the middle, convergent at the ends, 13 in 10 [mu]; axial area about
+one-fourth the width of the valve, widened in the middle; median line with
+small semicircular terminal fissures. L. 65 [mu].
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 30, Fig. 25.
+
+
+PINNULARIA PARVA (EHR.) CL. VAR. ?
+
+Valve linear, tapering to the subcapitate ends; axial area broad,
+lanceolate; median line with approximate central pores and semicircular
+terminal fissures; striae slightly divergent in the middle and convergent
+at the ends, 12 in 10 [mu]. L. 58 [mu].
+
+Differs from the type in having finer striae.
+
+Atco, N. J.
+
+Pl. 30, Fig. 14.
+
+
+PINNULARIA NODOSA FORMA CAPITATA CL.
+
+Valve triundulate, with capitate ends; axial area about one-fourth the
+width of valve; striae parallel, convergent at the ends, 10 in 10 [mu],
+sometimes interrupted in the middle. L. 47 [mu].
+
+Fresh water. Common.
+
+Pl. 30, Figs. 15 and 19.
+
+
+PINNULARIA POLYONCA (BREB.) LEWIS
+
+Valve with triundulate margins, more inflated in the middle, with capitate
+ends; axial area very broad; striae marginal, short, 9 in 10 [mu],
+divergent in the middle, convergent at the ends. L. 97 [mu].
+
+Kirkwood Pond, N. J.
+
+Pl. 30, Fig. 21.
+
+The description of Kuetzing (Species Algarum, p. 85), where he states that
+the margins are "triundulate, the median inflation larger, apices
+rounded-capitate," appears to sufficiently distinguish this species, which
+I believe to be the same as Brun's Navicula peripunctata, except that the
+form figured (Especes Nouvelles, Pl. 16, Fig. 11) is interrupted in the
+middle, a common variation in these forms. Cleve makes Navicula polyonca
+Breb. equal Pinnularia mesolepta, but at the same time he considers Lewis'
+form and also Brun's as equivalent to Navicula formica Ehr., and calls it
+Pinnularia nodosa var. formica Ehr. P. mesolepta has a narrower area than
+nodosa. I adhere to Lewis' identification, as in any case it is the form
+here figured and is nearly, if not quite, the same as Brun's species.
+
+
+{109}DISTANTES
+
+PINNULARIA LATA (BREB.) WM. SM.
+
+Valve linear-elliptical, broad; axial area broad, widened in the middle;
+striae slightly radiate in the middle, 3 in 10 [mu]; median line oblique,
+the terminal fissures hook-shaped. L. 86 [mu].
+
+Blue clay. Not uncommon.
+
+Pl. 30, Fig. 23.
+
+
+PINNULARIA BOREALIS EHR.
+
+Valve linear, with rounded or sub-truncate ends; axial area about
+one-fourth the width of the valve, widened in the middle; median line with
+large hook-shaped terminal fissures; striae, 4 or 5 in 10 [mu]. L. 54 [mu].
+
+Blue clay. Occasional in fresh water in a smaller form. Specimens occur
+intermediate between P. lata and P. borealis.
+
+Pl. 30, Fig. 22; Pl. 31, Fig. 12.
+
+
+PINNULARIA BOREALIS VAR. SCALARIS (EHR.) CL.
+
+Valve narrow, linear; axial area broad, widened into a transverse fascia;
+striae, 8 in 10 [mu]. L. 32 [mu].
+
+Fresh water.
+
+Pl. 30, Fig. 24.
+
+
+TABELLARIAE
+
+PINNULARIA STOMATOPHORA (GRUN.) CL.
+
+Valve linear, with rounded ends; axial area less than one-third the width
+of the valve, gradually widened in the middle to a transverse fascia; on
+each side of the central nodule is a lunate space; striae divergent in the
+middle, convergent at the ends, 13 in 10 [mu]; terminal fissures very long,
+bayonet shaped. L. 75 [mu].
+
+Cleve describes a variety continua as not interrupted. In some forms the
+fascia is marked by very faint, short striae on the margin.
+
+Fresh water. Newtown Square.
+
+Pl. 30, Fig. 12.
+
+
+PINNULARIA GIBBA (KUETZ.) V. H.
+
+Valve linear, tapering to the subcapitate ends; axial area dilated in the
+middle; striae, 10-11 [mu], divergent in the middle, convergent at the
+ends. L. 80 [mu].
+
+Fresh water.
+
+Pl. 30, Fig. 5.
+
+
+PINNULARIA MESOGONGYLA (EHR.) CL.
+
+Valve linear, gibbous in the middle, ends subcapitate; axial area narrow,
+widened in the middle to a large orbicular space; striae strongly divergent
+in the middle, convergent at the ends, 11 in 10 [mu]. L. 60 [mu].
+
+Fresh water. Common.
+
+Pl. 30, Fig. 6.
+
+
+{110}PINNULARIA STAUROPTERA (GRUN.) CL.
+
+Valve linear, with slightly triundulate margins tapering to the subcapitate
+ends; axial area more than one-third the width of the valve, slightly
+widened in the middle; median line with approximate central pores and
+semicircular terminal fissures; striae divergent in the middle, convergent
+at the ends, 11 in 10 [mu]. L. 82 [mu].
+
+May's Landing, N. J.
+
+Pl. 30, Fig. 13.
+
+Some of the forms are more triundulate than the specimen figured.
+
+
+PINNULARIA STAUROPTERA VAR. INTERRUPTA CL.
+
+Valve linear, tapering to the subcapitate ends; axial area broad, widened
+in the middle to a transverse fascia; striae divergent in the middle,
+convergent at the ends, 10 in 10 [mu]; median pores approximate. L. 118
+[mu].
+
+Schuylkill River.
+
+Pl. 30, Fig. 11.
+
+
+PINNULARIA TABELLARIA (EHR.) CL.
+
+Valve linear, gibbous in the middle and tapering to the subcapitate ends;
+axial area about one-third the width of the valve, widened in the middle;
+median line with approximate central pores and bayonet-shaped terminal
+fissures; striae sometimes unilaterally interrupted, divergent in the
+middle, strongly convergent at the ends, 9 in 10 [mu]. L. 138 [mu].
+
+Blue clay. Rare.
+
+Pl. 30, Fig. 9.
+
+The form here figured has coarser striae than in the type which is also
+usually more capitate.
+
+P. legumen has triundulate margins, P. mesogongyla has an orbicular space,
+while P. gibba has the space widened. According to Cleve, P. gibba has
+approximate central pores, as has also P. mesogongyla. In what I have
+considered to be P. legumen, the central pores are more approximate than in
+the other two species mentioned. In fact, all of the three resemble each
+other closely, and are variously named by different authors. The form of P.
+gibba here figured, which may be P. stauroptera, is not the typical form of
+Wm. Smith, which has a narrow area and central space. There are, however,
+among the typical specimens in H. L. Smith's Type Slide No. 275, smaller
+valves which show a resemblance.
+
+
+MARINAE
+
+PINNULARIA RECTANGULATA (GREG.) CL.
+
+Valve linear, with abruptly rounded ends; axial area very narrow; central
+area large, somewhat quadrate; striae, 7-8 in 10 [mu]. L. 78 [mu].
+
+_Navicula rectangulata Greg._
+
+Shark River, N. J.
+
+Pl. 29, Fig. 7.
+
+
+{111}EPITHEMIA BREB. (1838)
+
+(epithema, a cover or lid)
+
+Frustules epiphytic, solitary, sometimes geminate, adherent on the ventral
+side at the ends; in zone view rectangular, sometimes tumid in the middle.
+Valve arcuate, having an interior costate stratum or transverse septa
+extending to the girdle, often detached, and an exterior valve surface with
+transverse rows of puncta. Central and terminal nodules not easily seen; in
+some species a true raphe is indicated.
+
+The resemblance between Epithemia and Eunotia has been already mentioned.
+In the shape and striation of the valves there is an approach to Cymbella.
+
+The genus is divided into two groups, one in which the costae alternate
+with double rows of puncta, as in E. turgida, and the other in which the
+rows of puncta are more than two.
+
+The endochrome usually consists of a band lying along the ventral zone and
+extending in two flaps on the valves.
+
+
+EPITHEMIA TURGIDA (EHR.) KUETZ.
+
+Valve arcuate, with ends subcapitate; costae radiate, 4 in 10 [mu],
+alternating with double rows of puncta. Median nodule central, the raphe
+curved toward the ventral edge which it closely follows.
+
+Parasitic on algae. Very common in fresh water, especially in ponds. In the
+figure the valve is asymmetrical with respect to the transverse axis, an
+unusual condition.
+
+Pl. 31, Fig. 14.
+
+
+EPITHEMIA ARGUS KUETZ.
+
+Valve with dorsal margin convex, and ventral margin nearly straight; ends
+rounded, constricted; costae robust, alternating with more than two rows of
+puncta; zone view rectangular, the thickened ends of the costae forming
+large nodules in a row along the edge of the valve next to the connecting
+zone.
+
+_Cystopleura argus_ (Ehr.) Kunze.
+
+Common in fresh water.
+
+Pl. 31, Figs. 15 and 21.
+
+
+EPITHEMIA ARGUS VAR. ?
+
+Valve strongly arcuate on the dorsal side and concave on the ventral;
+tapering to the rounded but not produced ends; costae at unequal distances,
+about 2 in 10 [mu]; granules in transverse rows, 8 in 10 [mu]. L. 100 [mu].
+
+Pensauken, N. J., artesian well.
+
+Pl. 31, Fig. 16.
+
+
+EPITHEMIA MUELLERI A. S. ?
+
+Valve broad, convex, slightly arcuate, with obtuse, somewhat constricted
+apices; costae about 4 in 10 [mu]; striae, 12-14 in 10 [mu]; in zone view
+the outline is rectangular, slightly tumid in the middle. L. 78 [mu].
+
+Blue clay.
+
+Pl. 31, Fig. 17.
+
+
+{112}EPITHEMIA ZEBRA VAR. PROBOSCIDEA (KUETZ.) GRUN.
+
+Valve convex on the dorsal, concave on the ventral side; costae, 3-4 in 10
+[mu], slightly radiating; apices recurved, capitate.
+
+Blue clay.
+
+Pl. 31, Fig. 18.
+
+
+EPITHEMIA GIBBERULA VAR. PRODUCTA GRUN.
+
+Valve narrow, lunate, with produced and arcuate apices; costae radiate, 3-4
+in 10 [mu]; striae, 16-18 in 10 [mu], punctate. L. 58 [mu], usually
+smaller.
+
+Blue clay.
+
+Pl. 31, Fig. 19.
+
+
+EPITHEMIA MUSCULUS KUETZ.
+
+Valve short, strongly arcuate on the dorsal, concave on the ventral side;
+apices slightly produced; costae radiate, about 5 in 10 [mu]; striae, 15 in
+10 [mu], punctate. L. 20-60 [mu].
+
+Shark River, N. J.
+
+Pl. 31, Fig. 20.
+
+
+EPITHEMIA MUSCULUS VAR. CONSTRICTA (BREB.) V. H.
+
+Frustule elliptical, slightly constricted in the middle. Valve convex on
+the dorsal, straight on the ventral side; costae about 4 in 10 [mu]; striae
+about 18 in 10 [mu], finely punctate. L. 45 [mu].
+
+_Epithemia succinta_ Breb.
+
+New Rochelle, N. Y.
+
+Pl. 31, Fig. 22.
+
+
+RHOPALODIA MUELLER (1885)
+
+(Rhopalodes, like a war club)
+
+Frustule in zone view linear, linear-elliptical (in our species), or
+clavate. Valve reniform or lunate; a raphe, not visible in some species in
+the usual position of the valve, is found along the convex edge or keel.
+Median and terminal nodules, although very small, can be determined. The
+name is more appropriate to the African species which are clavate. Two
+species only are found in this locality.
+
+The chief distinction between Epithemia and Rhopalodia is in the position
+of the raphe and the nodules. In R. gibba and R. ventricosa the costae are
+parallel and not radiate since the valves are not lunate.
+
+Chromatophore a single band irregularly divided.
+
+
+RHOPALODIA GIBBA (KUETZ.) MUELLER
+
+Valve linear, arcuate on the dorsal, straight on the ventral side, reflexed
+at the extremities. Costae, 6-7 in 10 [mu]; striae about 14 in 10 [mu]. L.
+80-200 [mu].
+
+Fresh water. Common.
+
+Pl. 31, Fig. 23.
+
+In this species the raphe and nodules can be seen only when the valve is
+examined at right angles to its usual position.
+
+
+{113}RHOPALODIA VENTRICOSA (KUETZ.) MUELLER
+
+Valve gibbous in the middle on the dorsal side, straight on the ventral
+side, with reflexed apices; costae, 7 in 10 [mu]; striae, 14-16 in 10 [mu].
+L. 40-100 [mu].
+
+The median nodule appears as a minute depression in the middle of the
+dorsal side. The two species usually occur together.
+
+_Epithemia gibba_ var. _ventricosa_ Kuetz.
+
+Pl. 31, Fig. 24.
+
+
+
+SURIRELLOIDEAE
+
+The Surirelloideae are usually understood to include the genera Surirella,
+Podocystis, Cymatopleura and Campylodiscus, all of which resemble each
+other more or less, either in having a keel or markings like the divisions
+of the keel in Surirella and a median line, or pseudoraphe. The genus
+Nitzschia also has a keel, but it does not border each side of the valve as
+in Surirella, being found either near one margin or between it and the
+centre. Certain of the Surirellae are allied to the group Tryblionella of
+the Nitzschiae, while forms of Stenopterobia are distinguished with
+difficulty from the group Sigmata.
+
+The following arrangement, therefore, is intended to include all genera
+having a keel or something which resembles it.
+
+_Hantzschia._--Valve asymmetrical; keels of the two valves opposite each
+other.
+
+_Nitzschia._--Valve asymmetrical; keels not (usually) opposite each other.
+
+_Surirella._--Valve usually symmetrical; a keel on each border.
+
+_Cymatopleura._--Valve without an elevated keel, but with markings like
+those of Surirella; undulated in zone view.
+
+_Campylodiscus._--Valves saddle-shaped.
+
+
+HANTZSCHIA GRUN. (1877)
+
+(named after C. A. Hantzsch)
+
+Valve arcuate, with rostrate ends; keel puncta short, prolonged into costae
+or extending across the valve; median nodule rudimentary; the keels of the
+two valves opposite each other.
+
+Distinguished from Nitzschia chiefly by the position of the keels.
+According to Mereschkowsky, however, two species of Nitzschia, N.
+lanceolata and N. spectabilis, show the same peculiarity.
+
+Chromatophores four, two on each of the zones (Mereschkowsky).
+
+
+HANTZSCHIA AMPHIOXYS (EHR.) GRUN.
+
+Valve slightly arcuate, with rostrate apices; keel puncta, 8 in 10 [mu];
+striae transverse, 16-18 in 10 [mu], punctate. L. 60 [mu].
+
+Quite variable.
+
+Fresh water.
+
+Pl. 32, Fig. 9.
+
+
+{114}HANTZSCHIA AMPHIOXYS VAR. MAJOR GRUN.
+
+Valve as in type, but the keel puncta are 5 in 10 [mu] and the striae are
+11-12 in 10 [mu]. L. 71 [mu].
+
+H. amphioxys var. major Grun. is stated to be 120 [mu] in length. The
+present form is smaller but corresponds in puncta and striation. Van Heurck
+remarks that it approaches H. virgata.
+
+Abundant in sand ripples on the beach at Cape May, N. J.
+
+Pl. 39, Fig. 4.
+
+Fig. 6, Pl. 39, is drawn from an authentic specimen of Wm. Smith's
+Nitzschia amphioxys, from England, and is introduced for comparison. The
+central nodule is not evident.
+
+Fig. 3, Pl. 39, is from a specimen from an unknown locality. The keel
+puncta are 6 and the striae 16 in 10 [mu].
+
+
+HANTZSCHIA VIRGATA (ROPER) GRUN.
+
+Valve arcuate on the dorsal side, nearly straight on the ventral side, with
+rostrate, recurved apices; keel puncta prolonged to one-third the width of
+the valve, 4 in 10 [mu]; transverse striae, 9-10 in 10 [mu]. L. 115 [mu].
+
+Shark River, N. J. (Kain).
+
+I have not been able to find this form on our coast. The figure is drawn
+from a specimen from another locality.
+
+Pl. 32, Fig. 23.
+
+
+HANTZSCHIA MARINA (DONK.) GRUN.
+
+Valve with dorsal margin slightly arcuate, ventral margin straight; apices
+rostrate and recurved; keel puncta, 6 in 10 [mu], prolonged into costae
+across the entire valve; transverse striae, 12 in 10 [mu], in double rows
+of alternating puncta between the costae. L. 106 [mu].
+
+_Epithemia marina_ Donkin.
+
+Along the coast.
+
+Pl. 32, Fig. 22.
+
+
+NITZSCHIA HASSALL (1845), em. GRUN. (1880)
+
+(named after Christian L. Nitzsch, of Halle)
+
+Frustules usually free, sometimes enclosed in tubes or united into a
+filament. Valves keeled, the keels of the two valves usually diagonally
+opposite (see Hantzschia); keel puncta short or prolonged.
+
+According to Mereschkowsky, there are at least two endochrome plates placed
+transversely on the zones; sometimes there are from four to six plates, in
+one species twenty granules and in another no trace of any endochrome
+whatever.
+
+The following analysis is that of Grunow as given in Cleve and Grunow's
+"Arctic Diatoms," and adopted and illustrated by Van Heurck in his
+"Synopsis."
+
+
+GROUPS
+
+1. _Tryblionella._--Keel very excentric, valve often folded; keel puncta
+indistinct, usually the same in number as the striae.
+
+2. _Panduriformes._--Valve broad, constricted in the middle, with more or
+less evident fold; keel very near the edge; keel puncta quite evident or
+apparently wanting.
+
+{115}3. _Apiculatae._--Keel very near the edge; valve linear or somewhat
+narrower in the middle; striae on the longitudinal fold fainter than on the
+remaining surface, or wanting; puncta not in quincunx.
+
+4. _Pseudo-Tryblionella._--Keel more or less close to the edge; valve with
+a more or less deep longitudinal fold over which the striae are spread in
+the same way as over the remaining surface; keel puncta always distinct.
+
+5. _Circumsutae._--Valve with more or less wide longitudinal fold; keel
+very excentric; keel puncta quite evident; surface of valve irregularly
+punctate and also traversed by rows of delicate puncta which belong to a
+different layer of the valve.
+
+6. _Dubiae._--Like the group Pseudo-Tryblionella, but the valves are not so
+much folded; frustules sometimes narrowed in the middle. The separation of
+species is difficult and, in part, doubtful. Keel excentric.
+
+7. _Bilobatae._--Like the group Dubiae, but with more central keel and so
+forming a transition to the group Pseudo-Amphiprora; valves without
+longitudinal folds.
+
+8. _Pseudo-Amphiprora._--Valve with quite central, sharp keel, arcuate,
+without longitudinal fold; keel puncta always evident; frustule narrowed in
+the middle with more or less marked central nodule.
+
+Includes two species not found in this locality.
+
+9. _Perrya._--Valve arched with very sharp central keel; not narrowed in
+the middle; keel puncta mostly on short or long lines which are sometimes
+interrupted.
+
+Includes six species not found in this locality.
+
+10. _Epithemioideae._--Keel excentric; keel puncta extended into costae
+across the entire valve.
+
+11. _Grunowia._--As in the group Epithemioideae, except that the costae are
+shorter, not extending across the valve; keel very excentric.
+
+12. _Scalares._--Like Grunowia, but with sharper, somewhat excentric keel;
+transverse section of frustule quadrangular.
+
+13. _Insignes._--Like Scalares, but with more central keel so that many of
+the forms are near the group Perrya; frustule somewhat sigmoid.
+
+14. _Bacillaria._--Keel central or nearly so; valve somewhat arched; keel
+sharp, as in the group Insignes.
+
+15. _Vivaces._--Keel moderately excentric; valve, according to position,
+semi-lanceolate, with keel puncta in short rows, or lanceolate with quite
+central keel. The valves have in many positions a resemblance to
+Hantzschia, so that N. vivax frequently becomes confounded with a form of
+H. amphioxys. The median keel puncta are not distant and a central nodule
+is not evident as is the case in all species of Hantzschia.
+
+16. _Spathulatae._--Like the group Bacillaria, but usually with very
+delicate striated valves; keel in valve view usually bordered with two
+parallel lines.
+
+17. _Dissipatae._--Like Vivaces and Spathulatae, but with smaller central
+keel and without parallel lines. Valves usually small, very delicately
+striated; no central nodule.
+
+18. _Sigmoideae._--Keel quite central; no parallel lines; frustule sigmoid;
+valve without longitudinal furrow; keel puncta not extended; no central
+nodule evident.
+
+19. _Sigmata._--Like Sigmoideae, but with a more excentric keel.
+
+20. _Obtusae._--Like Sigmata, with a more or less excentric keel which has
+in the middle a small bending to the inside; middle keel puncta somewhat
+more distant than the others, and between them a central nodule evident.
+
+{116}21. _Spectabiles._--Valve large, slightly arcuate, with excentric
+keel; no longitudinal folds; keel puncta somewhat extended over the valve
+but much less than in the group Insignes, and often scarcely perceptible.
+
+22. _Lineares._--Keel somewhat excentric, but less than in Spectabiles;
+frustule straight, sometimes a little constricted in the middle, so that a
+transition is shown to the groups Dubiae and Bilobatae. Valve without
+longitudinal fold; keel puncta round or somewhat angular, scarcely
+extended.
+
+23. _Lanceolatae._--Valve lanceolate, linear-lanceolate or rarely
+elliptical, with very excentric keel; not folded; keel puncta not extended.
+
+24. _Nitzschiella._--Valve with excentric keel and long, produced apices.
+
+
+TRYBLIONELLA
+
+NITZSCHIA TRYBLIONELLA HANTZSCH
+
+Valve elliptical-lanceolate, with subacute apices; longitudinal fold well
+marked; striae coarse, transverse, 5 in 10 [mu]; indistinct puncta
+intermediate between the striae. L. 45 [mu]. Quite variable.
+
+Blue clay.
+
+Pl. 32, Fig. 8.
+
+
+NITZSCHIA GRANULATA GRUN.
+
+Valve elliptical or elliptical-lanceolate; striae in double rows, each row
+of three or four small puncta along the margin and rows of large puncta
+about 6 in 10 [mu] across the valve. L. 28-44 [mu].
+
+Blue clay. Along the coast.
+
+Pl. 32, Fig. 3.
+
+
+NITZSCHIA NAVICULARIS (BREB.) GRUN.
+
+Valve elliptical-lanceolate, with acute apices; striae on one side a double
+row of large and small puncta, and on the other side radiate short rows of
+large puncta, 7 in 10 [mu]; middle of valve hyaline. L. 35-60 [mu].
+
+Blue clay. Not common.
+
+Pl. 32, Fig. 4.
+
+
+NITZSCHIA COMPRESSA (BAIL.)
+
+Valve elliptical-lanceolate, sometimes acuminate; striae, 6 or 7 in 10
+[mu], coarsely punctate. L. 56 [mu].
+
+_Pyxidicula compressa_ Bailey.
+
+_Nitzschia punctata_ (Wm. Sm.) Grun.
+
+_Tryblionella punctata_ Wm. Sm.
+
+Common along the coast.
+
+Pl. 39, Fig. 7.
+
+Var. minor (H. L. Smith).--Valve acuminate; striae, 8 in 10 [mu]. L. 22
+[mu].
+
+_Pyxidicula compressa_ var. _minor_ H. L. Smith, Type Slide No. 431.
+
+Pl. 39, Fig. 8.
+
+The smaller forms occur northward, while the larger are found southward.
+This is unquestionably Bailey's form, as indicated by his figure and by the
+fact that it is found everywhere along the coast. Wm. Smith's T. punctata
+is the same species, although the puncta are smaller.
+
+
+{117}PANDURIFORMES
+
+NITZSCHIA PANDURIFORMIS GREG.
+
+Valve elliptical, constricted in the middle, with sub-cuneate apices;
+longitudinal fold, with a punctate longitudinal line; striae transverse and
+oblique, 15 in 10 [mu]; keel puncta, 6 in 10 [mu]. L. 108 [mu].
+
+Along the coast. More often found southward.
+
+Pl. 39, Fig. 2.
+
+
+NITZSCHIA PANDURIFORMIS VAR. MINOR GRUN.
+
+Valve elliptical, constricted in the middle, with cuneate apices; keel
+puncta, 9 in 10 [mu]; striae in transverse and oblique lines about 20 in 10
+[mu]; longitudinal fold bordered by a punctate line. L. 34 [mu].
+
+Pavonia, N. J., artesian well.
+
+Pl. 32, Fig. 5.
+
+The var. continua Grun. is reported as occurring in Shark River. It varies
+in having the longitudinal fold punctate. It is also usually smaller than
+var. minor.
+
+
+APICULATAE
+
+NITZSCHIA APICULATA (GREG.) GRUN.
+
+Valve oblong-linear, with cuneate-apiculate apices; striae punctate,
+apparently interrupted or pervious, about 18 in 10 [mu]. L. 26 [mu].
+
+Chester River, Md.
+
+Pl. 32, Fig. 6.
+
+The puncta are continued across the valve, but are less distinct on the
+fold. The figure shows the entire frustule with the fold on each valve. The
+valves are sometimes slightly constricted.
+
+
+NITZSCHIA ACUMINATA (WM. SM.) GRUN.
+
+Valve linear, sometimes slightly constricted in the middle, with acuminate
+apices; longitudinal fold entirely without or with indistinct striae; keel
+puncta not evident; striae, 14-15 in 10 [mu]. L. 82 [mu].
+
+Port Penn, Delaware River.
+
+Pl. 32, Fig. 13.
+
+
+NITZSCHIA PLANA WM. SM.
+
+Valve linear; apices acute, slightly constricted in the middle;
+longitudinal fold further from the keel than the margin, broad, with
+scattered puncta; striae subtle, irregular, interrupted, about 18 in 10
+[mu]; keel puncta oblong, 3-6 in 10 [mu]. L. 100-170 [mu].
+
+Blue clay. Along the coast.
+
+Pl. 32, Fig. 2.
+
+
+{118}PSEUDO-TRYBLIONELLA
+
+NITZSCHIA LITORALIS VAR. DELAWARENSIS GRUN.
+
+Valve linear, with obtusely rounded cuneate ends, scarcely, if at all,
+constricted in the middle; longitudinal fold wide; keel puncta, 5 or 6 in
+10 [mu], sometimes confluent; striae obscure, about 21 in 10 [mu]. L. 75
+[mu].
+
+Delaware River.
+
+Pl. 32, Fig. 12.
+
+This form is drawn from a slide of Christian Febiger containing an
+abundance of specimens from Delaware City, and marked "Nitzschia dubia."
+
+
+CIRCUMSUTAE
+
+NITZSCHIA CIRCUMSUTA (BAIL.) GRUN.
+
+Valve elliptical, sometimes more than 200 [mu] in length; longitudinal fold
+more or less conspicuous; keel puncta about 4 in 10 [mu], the middle
+distant with the appearance of a nodule; striae irregular, subtle, finely
+punctate, frequently interrupted.
+
+_Surirella circumsuta_ Bail.
+
+_Tryblionella scutellum_ Wm. Sm.
+
+Common in brackish water.
+
+Pl. 32, Fig. 1.
+
+
+DUBIAE
+
+NITZSCHIA DUBIA WM. SM.
+
+Valve linear, scarcely, if at all, constricted in the middle, with cuneate,
+produced, apiculate apices, somewhat recurved; keel very excentric; puncta
+sometimes partly prolonged, about 9 in 10 [mu]; striae, 20-24 in 10 [mu].
+L. 93 [mu].
+
+Reported from along the New Jersey coast. I have not seen it. It is
+generally regarded as fresh-water. Slides sometimes labelled N. dubia are
+in reality N. litoralis var. delawarensis.
+
+Pl. 39, Fig. 5.
+
+The figure is drawn from a specimen from another locality.
+
+
+BILOBATAE
+
+NITZSCHIA BILOBATA WM. SM.
+
+Valve linear-lanceolate, constricted in the middle, apiculate at the ends;
+keel puncta 6 in 10 [mu], prolonged unequally across part of the valve, the
+two median sub-remote; striae, 16 in 10 [mu]. Frustule oblong, truncate,
+constricted in the middle. L. 120 [mu].
+
+Shark River, N. J., Chester River, Md.
+
+Pl. 32, Figs. 10 and 11.
+
+
+EPITHEMIOIDEAE
+
+NITZSCHIA EPITHEMIOIDES GRUN.
+
+Valve linear, with cuneate, rostrate apices; slightly constricted on the
+keel side; keel puncta, 8 or 9 in 10 [mu], extending as costae across the
+valve; striae delicate, 22 in 10 [mu]. L. 47 [mu].
+
+Brackish water, Long Island Sound.
+
+Pl. 32, Fig. 21.
+
+
+{119}GRUNOWIA
+
+NITZSCHIA TABELLARIA GRUN.
+
+Valve rhomboidal, inflated in the middle; apices produced; keel puncta
+extend in costae across half of the valve, 7 in 10 [mu]; striae transverse,
+about 22 in 10 [mu]. L. 20 [mu].
+
+_Dimerogramma sinuatum_ Thwaites.
+
+_Nitzschia sinuata_ var. _tabellaria_ (Grun.) V. H.
+
+Schuylkill River. Not common.
+
+Pl. 32, Fig. 7.
+
+
+SCALARES
+
+NITZSCHIA SCALARIS (EHR.) WM. SM.
+
+Valve linear, with obtusely conical apices; costae transverse, extending
+more or less to one-third the width of the valve, 3 or 4 in 10 [mu];
+striae, 9 or 10 in 10 [mu], punctate. Length of valve quite variable, up to
+480 [mu] (Cleve).
+
+A well-known form, abundant in salt marshes and more or less brackish
+water.
+
+Pl. 33, Fig. 6. (To the right of the figure is an outline of the valve
+reduced one-third.)
+
+
+INSIGNES
+
+NITZSCHIA INSIGNIS GREG.
+
+Valve nearly linear or linear-lanceolate; apices broad, slightly produced,
+obtuse; keel puncta extended into short costae, 4 or 5 in 10 [mu]; striae
+about 14 in 10 [mu]. Length variable up to 400 [mu].
+
+Delaware Bay.
+
+Pl. 33, Fig. 8.
+
+
+BACILLARIA
+
+NITZSCHIA PAXILLIFER (O. F. MUELLER) HEIBERG
+
+Frustules united in a filament, afterwards free; valve lanceolate with
+nearly central keel; keel puncta, 7-9 in 10 [mu]; striae about 21 in 10
+[mu]. L. 110 [mu].
+
+_Vibrio paxillifer_ O. F. Mueller.
+
+_Bacillaria paradoxa_ Gmelin.
+
+_Nitzschia paradoxa_ (Gmelin) Grun.
+
+Brackish water or streams subject to its influence.
+
+Pl. 33, Figs. 13 and 14.
+
+Otto Frederick Mueller, in 1786, published at Copenhagen a work on
+"Infusorial Animalcules," including a description of a Vibrio which he
+named paxillifer, obviously alluding to the partially-extended frustules
+bearing at the end a tablet-like bundle. Two years later, Gmelin described
+the same form as Bacillaria paradoxa, a name still used. Heiberg, however,
+in 1863, placed the form under Nitzschia where it properly belongs and
+called it Nitzschia paxillifer (O. F. Mueller). I have adopted Heiberg's
+name.
+
+Perhaps the most remarkable of all diatoms. Many species possess the power
+of motion, which, however, is evident only in the free frustule. In N.
+paxillifer, the movement of the frustules occurs without the loss of
+continuity or adherence to each other, so that, while at one time the
+adnate frustules form a narrow filament, like that of Fragilaria, at
+another {120}time they move laterally to their extreme length and form a
+thread of frustules adherent at their ends, later resuming their original
+position. The motion is repeated at intervals of from five to ten seconds.
+No satisfactory explanation of the movement has ever been made. In the
+filamentous form the frustules adhere to water-plants.
+
+
+VIVACES
+
+NITZSCHIA FLUMINENSIS GRUN.
+
+Valve lanceolate, apices produced; keel puncta, 4-6 in 10 [mu], partly
+extended in short costae; striae transverse, 14-15 in 10 [mu], punctate;
+keel without a pseudo-nodule. L. 73 [mu].
+
+Common at Greenwich Point, Philadelphia.
+
+Pl. 32, Fig. 16.
+
+The form here figured is smaller than the type, which is from 130-160 [mu]
+in length.
+
+
+SPATHULATAE
+
+NITZSCHIA SPATHULATA BREB.
+
+Frustule linear, truncate, dilated at the ends; zone with longitudinal
+folds; valve lanceolate, keel central; apices acute, with an elevated
+appendage; keel puncta, 5-6 in 10 [mu]; striae very fine. L. 56 [mu].
+
+Atlantic City and Cape May, N. J. (Lewis).
+
+Pl. 40, Fig. 3.
+
+
+DISSIPATAE
+
+NITZSCHIA DISSIPATA (KUETZ.) GRUN.
+
+Valve lanceolate, with sub-rostrate apices; keel excentric; keel puncta
+about 6 in 10 [mu]; striae, 14 in 10 [mu]. L. 20-40 [mu].
+
+Fresh and brackish water.
+
+Pl. 40, Fig. 7.
+
+
+SIGMOIDEAE
+
+NITZSCHIA MACILENTA GREG.
+
+Frustule sigmoid, truncate at the ends; valve linear, with sub-acute apices
+and nearly central keel; keel with 5-6 puncta in 10 [mu]; striae obscure,
+about 25 to 28 (?) in 10 [mu]. Length variable, up to 490 [mu].
+
+As the valve is usually seen when the keel is on the margin, the outline
+(reduced one-third, shown to the left of the figure) is, as a rule,
+sigmoid.
+
+Delaware Bay.
+
+Pl. 33, Fig. 7.
+
+
+NITZSCHIA VERMICULARIS (KUETZ.) HANTZSCH
+
+Valve linear, sigmoid, attenuated toward the obtuse ends; keel puncta, 9 in
+10 [mu], quite distinct; striae very fine. L. 105 [mu].
+
+Fresh-water pools.
+
+Pl. 32, Fig. 24; Pl. 33, Fig. 9.
+
+
+{121}SIGMATA
+
+NITZSCHIA SIGMA (KUETZ.) WM. SM.
+
+Frustule linear, sigmoid; valve linear, slightly sigmoid, tapering to the
+sub-acute apices; keel excentric, puncta, 8 in 10 [mu]; striae, 20-24 in 10
+[mu]. L. to 250 [mu].
+
+Along the coast.
+
+Pl. 39, Fig. 13.
+
+
+NITZSCHIA SIGMATELLA GREG.
+
+Valve linear, sigmoid, slightly attenuated toward the obtuse apices; keel
+excentric, puncta, 8-10 (?) in 10 [mu]; striae delicate, 25-30 in 10 [mu].
+L. to 400 [mu]. The keel puncta are quite obscure.
+
+_Nitzschia curvula_ Wm. Sm.
+
+_Nitzschia sigma_ var. _curvula_ (Wm. Sm.) De Toni.
+
+Fresh water. Hammonton Pond; May's Landing, N. J.
+
+Pl. 33, Figs. 4 and 5.
+
+Gregory remarks that the keel puncta are seen in some specimens. In both of
+the forms figured I have counted 30 striae in 10 [mu], but, after many
+examinations, I have not been quite certain about the keel puncta. The
+general appearance of the valves in any position is that of a Stenopterobia
+or Surirella anceps, with which it occurs.
+
+
+NITZSCHIA CLAUSII HANTZSCH
+
+Valve linear, slightly sigmoid, tapering to the sub-capitate ends; keel
+puncta, 11 in 10 [mu]; striae subtle. L. 40 [mu].
+
+Abundant in Ridley Creek, Delaware Co. (Palmer).
+
+Pl. 32, Fig. 20.
+
+
+OBTUSAE
+
+NITZSCHIA OBTUSA WM. SM.
+
+Frustule sigmoid, rounded at the ends; keel somewhat excentric, inflexed in
+the middle, the two median puncta distant; keel puncta, 5-6 in 10 [mu];
+striae, 26 in 10 [mu]. L. to 300 [mu].
+
+Along the coast.
+
+Pl. 39, Fig. 16.
+
+
+NITZSCHIA OBTUSA VAR. FLEXELLA H. L. SMITH
+
+Valve more attenuate at the ends than the type and smaller.
+
+Pl. 39, Fig. 14.
+
+
+NITZSCHIA OBTUSA VAR. SCALPELLIFORMIS GRUN.
+
+Valve linear, with apices unilaterally truncate; keel excentric; keel
+puncta, 8 in 10 [mu]; striae, 26 in 10 [mu]. L. 48 [mu].
+
+Along the coast.
+
+Pl. 32, Fig. 17.
+
+
+{122}SPECTABILES
+
+NITZSCHIA SPECTABILIS VAR. AMERICANA GRUN.
+
+Frustule linear, slightly constricted in the middle, with sub-cuneate ends;
+valve linear, slightly arcuate, tapering to the sub-rostrate ends; keel
+excentric, keel puncta sometimes confluent, 4-6 in 10 [mu], prolonged into
+short costae; striae distinct, 14 in the middle, 18 at the ends in 10 [mu]
+(but variable in different specimens). L. 186 [mu].
+
+Blue clay, especially at Tioga St.
+
+Pl. 33, Fig. 3; Pl. 39, Fig. 1.
+
+This is, probably, one of the most beautiful of the Nitzschiae. It
+sometimes, according to De Toni, reaches a length of 520 [mu].
+
+Grunow states that his variety is found in the S. Bridgeton deposit. In a
+slide of Moeller labelled "Bridgeton, Maine," I find specimens identical in
+every respect with the Philadelphia form.
+
+
+LINEARES
+
+NITZSCHIA LINEARIS (AG.) WM. SM.
+
+Valve linear, slightly inflexed in the middle; keel excentric; keel puncta,
+8-9 in 10 [mu], the two median distant; striae about 30 in 10 [mu].
+Frustules in zone view narrowed toward the ends, truncate. L. 75 [mu].
+
+Very common in fresh water.
+
+Pl. 32, Fig. 18. Fig. 20, Pl. 40, a transverse section of frustule.
+
+
+LANCEOLATAE
+
+NITZSCHIA PALEA (KUETZ.) WM. SM.
+
+Valve linear-lanceolate, slightly rostrate at the apices; keel puncta, 10
+in 10 [mu], the median not distant; striae, 33-36 in 10 [mu]; zone view
+linear, with rounded ends. L. 25-65 [mu].
+
+Fresh water.
+
+Pl. 32, Fig. 15.
+
+
+NITZSCHIA AMPHIBIA GRUN.
+
+Valve lanceolate, apices sometimes slightly produced, rounded; keel puncta,
+8-9 in 10 [mu]; striae, 16 in 10 [mu]. L. 20-32 [mu].
+
+Fresh water.
+
+Pl. 32, Figs. 14 and 25.
+
+
+NITZSCHIA COMMUNIS RAB.
+
+Frustule linear, slightly attenuated at the obtuse ends; valve
+elliptical-lanceolate, attenuated toward the obtuse ends; keel puncta, 12
+in 10 [mu]; striae more than 30 in 10 [mu]. L. 35 [mu].
+
+Fresh water.
+
+Pl. 32, Fig. 19.
+
+
+NITZSCHIA INTERMEDIA HANTZSCH
+
+Valve linear-lanceolate; keel puncta, 8 in 10 [mu]; striae about 24 in 10
+[mu]. L. 100 [mu].
+
+Crum Creek. Not common.
+
+Pl. 33, Fig. 2.
+
+
+{123}NITZSCHIELLA
+
+NITZSCHIA LONGISSIMA (BREB.) RALFS
+
+Valve linear-lanceolate, with exceedingly long horns or beaks; keel puncta
+about 10 in 10 [mu]; striae about 16 in 10 [mu]. L. to 500 [mu].
+
+Shark River, N. J.
+
+Pl. 33, Fig. 1.
+
+Forma parva V. H.--Keel puncta, 10-12 in 10 [mu]. L. 70 [mu].
+
+East Park Reservoir, Philadelphia.
+
+Pl. 33, Fig. 10.
+
+Differs from N. closterium (Ehr.) Wm. Sm. in the keel puncta.
+
+The type form occurs in brackish and salt water. The occurrence of the
+variety in fresh water is another instance of the finding of presumably
+brackish forms in the water supply of the city. If these cases prove to be
+unusual, it may be because of one of two reasons. The Schuylkill River,
+before the building of the dam at Fairmount, was tidal as far as the Falls
+of Schuylkill, and brackish influences, while not now existent, may have
+caused the growth of forms which now survive. Another reason may be that
+the opening of the locks at Fairmount Dam may cause a slight admission of
+brackish forms from tidal water below. The abundance of the brackish
+species appears to indicate that the first reason is the more plausible.
+
+
+NITZSCHIA REVERSA WM. SM.
+
+Valve lanceolate extended into beaks or horns curving in opposite
+directions; keel puncta not evident; striae, "20-26" in 10 [mu]. L. 70
+[mu].
+
+Brackish water. Abundant in Duck Creek, Delaware River.
+
+Pl. 33, Fig. 11.
+
+
+NITZSCHIA ACICULARIS (KUETZ.) WM. SM.
+
+Valve lanceolate, with beaks or horns about half the length of the median
+part of the valve; keel puncta, 18 in 10 [mu]; striae exceedingly delicate,
+"about 40 in 10 [mu]." L. 45 [mu].
+
+Fresh water. Darby Creek.
+
+Pl. 33, Fig. 12.
+
+
+HOMOEOCLADIA AG. (1827)
+
+(homoios, like, and clados, a branch)
+
+Frustules like Nitzschia, but enclosed in branching or simple tubes.
+
+
+HOMOEOCLADIA FILIFORMIS WM. SM.
+
+Frustule linear, tumid in the middle, obtuse at the ends; valve
+linear-lanceolate, with somewhat acute apices; keel central or nearly so;
+keel puncta, 8 in 10 [mu]; striae delicate. L. 108 [mu].
+
+Fresh and brackish water. Newark, N. J.
+
+Pl. 33, Fig. 15.
+
+
+{124}SURIRELLA TURPIN (1828)
+
+(named after Dr. Suriray, a physician of Havre)
+
+Valve linear, elliptical or ovate; pseudoraphe linear or lanceolate; a
+marginal keel forming wings or alae seen in zone view; costae short or
+reaching the pseudoraphe, frequently with intercostal striae more or less
+evident.
+
+The genus is divided by Grunow according to the length and form of the
+costae. I include Stenopterobia.
+
+Section 1.--Costae of nearly equal width throughout, reaching the
+pseudoraphe.
+
+Section 2.--Costae short or marginal.
+
+Section 3.--Costae dilated at the margin, attenuated toward the
+pseudoraphe.
+
+Section 4.--Valve having the appearance of Nitzschia, with inconspicuous
+alae (Stenopterobia).
+
+The endochrome consists of two laminate chromatophores, one on each valve.
+
+The auxospores are single, originating from the union of two frustules (H.
+L. Smith).
+
+
+SECTION 1
+
+SURIRELLA BISERIATA (EHR.) BREB.
+
+Valve lanceolate, subacute at the ends; costae robust, about 2 in 10 [mu],
+parallel in the middle, radiate at the ends; pseudoraphe narrow. L. 100
+[mu].
+
+_Surirella bifrons_ Ehr.
+
+Fresh water.
+
+Pl. 39, Fig. 12; Pl. 35, Fig. 2 (smaller form).
+
+
+SURIRELLA LINEARIS WM. SM.
+
+Valve linear, with cuneate ends, slightly constricted in the middle; costae
+parallel, 2-3 in 10 [mu]. L. 90 [mu].
+
+Fresh water.
+
+Pl. 35, Fig. 8.
+
+
+SURIRELLA AMPHIOXYS WM. SM.
+
+Valve oblong-linear, with cuneate ends; pseudoraphe narrow; costae, 3-4 in
+10 [mu]; striae, 14-16 in 10 [mu], somewhat radiate. L. 34-54 [mu].
+
+_Surirella moelleriana_ Grun.
+
+Fresh and brackish water. Common along the coast.
+
+Pl. 35, Figs. 12 and 13.
+
+
+SURIRELLA ROBUSTA EHR.
+
+Valve linear-ovate; pseudoraphe wide; alae prominent; costae wide, 1-1/4 in
+10 [mu]. Frustule in zone view clavate. L. 200-365 [mu].
+
+Fresh water.
+
+Pl. 36, Fig. 2.
+
+
+{125}SURIRELLA SPLENDIDA (EHR.) KUETZ.
+
+Valve ovate; costae, 1-1/2 to 2 in 10 [mu]; pseudoraphe linear, narrow. L.
+125-200 [mu].
+
+Fresh water.
+
+Pl. 35, Fig. 3.
+
+S. splendida is smaller than S. robusta and wider in proportion, but, as
+intermediate forms occur, it is difficult to distinguish between them.
+
+
+SURIRELLA ELEGANS EHR.
+
+Valve ovate, rounded at one end and acute at the other; pseudoraphe
+lanceolate, narrow; costae, 1-1/2 in 10 [mu]; striae subtle, 22 in 10 [mu].
+Frustule in zone view cuneate. L. 180-220 [mu].
+
+Fresh water.
+
+Pl. 36, Fig. 1.
+
+
+SURIRELLA STRIATULA TURPIN
+
+Valve broad, obovate or elliptical, rounded at each end; costae, 1-1/4 in
+10 [mu], curved at the ends; striae, 14 in 10 [mu]. Frustule in zone view
+cuneate; marginal alae quite robust. L. 100-160 [mu].
+
+Blue clay. Brackish water.
+
+Pl. 34, Fig. 1.
+
+In the specimen figured, the outline is exactly elliptical, although the
+species is usually conical at one end.
+
+
+SURIRELLA GEMMA EHR.
+
+Valve ovate or ovate-elliptical, rounded at each end, sometimes
+asymmetrical along the longitudinal axis; pseudoraphe very narrow; costae
+distant, at irregular intervals, about 2 in 10 [mu], somewhat radiate,
+reaching the pseudoraphe; striae, 20 in 10 [mu], punctate. Frustule in zone
+view cuneate. L. 70-120 [mu].
+
+Along the coast.
+
+Pl. 36, Fig. 4.
+
+
+SURIRELLA TENERA GREG.
+
+Valve ovate; pseudoraphe narrow, well-defined; costae indistinct, 2-1/2 in
+10 [mu], their margins invisible; striae about 14 in 10 [mu], punctate,
+more evident near the margin. L. 90 [mu].
+
+_Surirella diaphana_ Bleisch.
+
+Pavonia, N. J., artesian well.
+
+Pl. 35, Fig. 6.
+
+The figure is that of the var. nervosa A. S. (Atlas, Pl. 23, Fig. 15),
+which differs from the type in having the position of the costae indicated
+by scattered puncta.
+
+
+{126}SECTION 2
+
+SURIRELLA GUATIMALENSIS EHR.
+
+Valve ovate; pseudoraphe very narrow and indistinct; costae short,
+marginal, 2-2-1/2 in 10 [mu], absent from the rounded end. L. 120 [mu].
+
+_Surirella cardinalis_ Kitton.
+
+Smith's Island, Delaware River.
+
+Pl. 36, Fig. 5.
+
+
+SURIRELLA OVALIS BREB.
+
+Valve ovate; costae short, marginal, radiate, 3-6 in 10 [mu], often
+unequal; central area ovate, indistinctly costate; striae scarcely visible,
+about 18 in 10 [mu]; pseudoraphe narrow. L. 45-93 [mu].
+
+_Surirella davidsonii_ A. S.
+
+Fresh or brackish water.
+
+Pl. 35, Fig. 5; Pl. 39, Fig. 11.
+
+The smaller specimen is from the Delaware River, and the larger from the
+Hudson River.
+
+
+SURIRELLA CRUMENA BREB.
+
+Valve nearly orbicular; costae short, marginal, radiate; pseudoraphe
+narrow, indistinct; central area indistinctly costate, sometimes
+interrupted.
+
+On account of the extreme confusion in the names of many forms which appear
+to be variations of S. ovalis, I have followed Van Heurck in retaining the
+original names as specific. De Toni gives S. crumena as a variety of S.
+ovalis.
+
+Fresh and brackish water. Quite common in the Delaware River.
+
+Pl. 35, Fig. 4.
+
+
+SURIRELLA PINNATA WM. SM.
+
+Valve ovate or oblong-ovate; costae reaching the linear pseudoraphe, about
+6 in 10 [mu]. L. 40 [mu].
+
+_Surirella ovalis_ var. _pinnata_ (Wm. Sm.) De Toni.
+
+S. pinnata is the type of a number of small forms usually found together,
+including S. panduriformis, S. angusta and S. minuta.
+
+Fresh water. Media (Palmer).
+
+Pl. 36, Fig. 7; Fig. 9 (abnormal).
+
+Var. minuta, a small form of S. pinnata, occurs with the type.
+
+
+SURIRELLA PANDURIFORMIS WM. SM.
+
+Valve linear-oblong, with rounded ends, more or less constricted in the
+middle; otherwise as in S. pinnata. L. 54 [mu].
+
+Fresh water.
+
+Pl. 36, Fig. 6.
+
+
+{127}SURIRELLA ANGUSTA KUETZ.
+
+Valve linear, with cuneate ends; otherwise as in S. pinnata.
+
+Fresh water.
+
+Pl. 36, Fig. 8.
+
+S. pinnata, S. panduriformis, and S. angusta have a narrow central area,
+and differ from S. ovalis which has short costae.
+
+
+SURIRELLA OBLONGA EHR. ?
+
+Valve elliptical-lanceolate, with obtuse ends; costae, marginal, 2-1/2 in
+10 [mu]; median area granulate; pseudoraphe narrow, lanceolate, scarcely
+visible; striae about 18 in 10 [mu]. L. 60 [mu].
+
+Blue clay. Rare.
+
+Pl. 35, Fig. 9.
+
+This has the outline and appearance of S. oblonga Ehr. (Mik. Pl. 15, Fig.
+48), but the costae are closer.
+
+
+SURIRELLA RECEDENS A. S.
+
+Valve ovate; costae, 2-2-1/2 in 10 [mu]; pseudoraphe narrow, not reaching
+the ends of the valve; intercostal spaces more evident near the middle. L.
+50 [mu].
+
+Blue clay. Not uncommon.
+
+Pl. 35, Fig. 7.
+
+
+SURIRELLA CRUCIATA A. S.
+
+Valve ovate; pseudoraphe very narrow; costae, 2 in 10 [mu]; the outline of
+several of the median costae strongly emphasized, while the other costae
+are indistinct. L. 54 [mu].
+
+Blue clay.
+
+Pl. 35, Fig. 10.
+
+
+SURIRELLA GRACILIS GRUN.
+
+Valve linear, with sub-cuneate ends, slightly constricted in the middle;
+pseudoraphe very narrow; costae, 6-7 in 10 [mu]; transverse striae about 26
+in 10 [mu], punctate. L. 75 [mu].
+
+According to De Toni (p. 598), this form is a Nitzschia. It has, however, a
+narrow pseudoraphe.
+
+Pavonia, N. J., artesian well. Rare.
+
+Pl. 35, Fig. 11.
+
+
+SECTION 3
+
+SURIRELLA FASTUOSA EHR.
+
+Valve ovate; costae about 1-2 in 10 [mu], dilated at the margin and
+contracting at about one-fourth the distance toward the middle; area,
+ovate-lanceolate; pseudoraphe, narrow and indistinct; intercostate striae
+more evident near the margin, 19 in 10 [mu], becoming again evident in a
+narrow band about one-half the distance to the pseudoraphe. L. 50-120 [mu].
+
+Along the coast. More common southward.
+
+Pl. 35, Fig. 1.
+
+
+{128}SURIRELLA FEBIGERII LEWIS
+
+Valve ovate-lanceolate; costae about 2-1/2 in 10 [mu] with punctate
+interspaces extending half the distance toward the median hyaline area,
+which is divided longitudinally on each side of the narrow pseudoraphe by
+two longitudinal bands composed of short, transverse, irregular, punctate
+lines.
+
+Along the coast.
+
+Pl. 36, Fig. 3.
+
+
+SECTION 4 (STENOPTEROBIA)
+
+SURIRELLA ANCEPS LEWIS
+
+Frustule linear, straight or nearly so; valve sigmoid with rounded apices;
+costae marginal, nearly obsolete; striae distinct, about 15 in 10 [mu];
+pseudoraphe wide. L. to 320 [mu].
+
+Hammonton Pond and Tom's River, N. J.
+
+Pl. 34, Fig. 2.
+
+
+SURIRELLA INTERMEDIA LEWIS
+
+Frustule linear, straight, widened at the truncate ends; valve linear,
+sigmoid, tapering to the sub-acute ends; costae about 5 in 10 [mu]; striae
+about 20 in 10 [mu]. L. variable.
+
+Hammonton Pond, N. J.
+
+Pl. 34, Fig. 3; Pl. 39, Fig. 9 (zone view).
+
+This, perhaps, is forma sub-acuta Fricke.
+
+Fig. 7, Pl. 34, is probably a small form of S. intermedia, from Willistown,
+Pa. It resembles a Nitzschia.
+
+
+SURIRELLA DELICATISSIMA LEWIS
+
+Frustule linear, rounded at the ends; valve linear-lanceolate, sometimes
+very slightly constricted in the middle, with acute apices; costae, 5 in 10
+[mu]; striae about 20 in 10 [mu]; pseudoraphe well defined, lanceolate. L.
+to 90 [mu].
+
+Fresh water. Newtown Square.
+
+Pl. 34, Figs. 5 and 6 (small forms).
+
+
+SURIRELLA ARCTISSIMA A. S.
+
+Valve linear, tapering to the sub-acute ends; costae marginal, 5 in 10
+[mu]; striae, 18 in 10 [mu]; pseudoraphe not evident. L. 184 [mu].
+
+May's Landing, N. J.
+
+Pl. 34, Fig. 4.
+
+Fig. 10, Pl. 39, is a small form from Newtown Square, Pa., in which the
+length is 86 [mu], the costae 5 and the striae 16 in 10 [mu].
+
+
+PODOCYSTIS KUETZ. (1844)
+
+(pous, a foot, and cystis, a bag)
+
+Frustules cuneate, similar to Surirella, but attached by short stipes to
+other algae; valve obovate.
+
+
+{129}PODOCYSTIS ADRIATICA KUETZ.
+
+Valve nearly symmetrical, obovate, with transverse costae about 4 in 10
+[mu], alternating with double rows of coarse puncta; median line distinct,
+linear. L. 43 [mu].
+
+_Podocystis americana_ Bail.
+
+Hell Gate, N. Y.
+
+Pl. 40, Fig. 6.
+
+
+CYMATOPLEURA WM. SM. (1851)
+
+(cuma, a wave, and pleura, a side)
+
+Valve elliptical; surface transversely undulate, with short, marginal
+costae. Frustule in zone view linear, with undulated sides.
+
+Auxospore formation as in Surirella.
+
+
+CYMATOPLEURA SOLEA (BREB.) WM. SM.
+
+Valve oblong, with cuneate apices, constricted in the middle; costae about
+6 in 10 [mu]; striae, 10 in 10 [mu]; pseudoraphe scarcely visible. L.
+50-300 [mu].
+
+Blue clay. Common in the Hudson River.
+
+Pl. 34, Figs. 8 and 9.
+
+
+CYMATOPLEURA ELLIPTICA (BREB.) WM. SM.
+
+Valve elliptical; marginal costae short, 3 in 10 [mu]; striae delicate, 18
+in 10 [mu]; undulations four or more. L. 70-140 [mu].
+
+Blue clay.
+
+Pl. 37, Fig. 1.
+
+_Forma spiralis._--Valve ovate, swelled into curved ridges at the lower
+end, with a contraction of the valve.
+
+Port Penn, Delaware River.
+
+Pl. 37, Fig. 2.
+
+
+CYMATOPLEURA MARINA LEWIS
+
+Frustule linear, with numerous undulations, ends apiculate; valve
+linear-lanceolate, with acute ends; striae transverse, punctate at unequal
+intervals, from 16-18 in 10 [mu]. L. 43 [mu].
+
+East River, N. Y.
+
+Pl. 37, Figs. 3 and 4.
+
+Lewis states that the ends are more or less truncate. I do not find them
+so.
+
+
+CAMPYLODISCUS EHR. (1841)
+
+(campulos, curved like a saddle)
+
+Valve orbicular or sub-orbicular, with costae or punctate rays converging
+from the circumference toward the hyaline centre, which sometimes appears
+like a pseudoraphe. Frustule of two saddle-shaped valves at right angles to
+each other. The zone view may be of almost any shape according to position.
+
+Endochrome consists of two bands, each lining the inner surface of each
+valve. Auxospore and conjugation unknown.
+
+
+{130}CAMPYLODISCUS ECHENEIS EHR.
+
+Valve sub-orbicular, saddle-shaped; costae indistinct, short, marginal;
+rows of round or elongated puncta converge toward the lanceolate, hyaline
+median space. Diam. 80-140 [mu].
+
+_Campylodiscus argus_ Bail.
+
+Blue clay. Reservoir at Thompson and Twenty-sixth Sts., Phila.
+
+Pl. 37, Fig. 6.
+
+This form, usually considered as brackish and marine, is occasionally found
+in fresh water. According to Deby, it is fossil in the "Champlain deposit
+of N. A."
+
+
+CAMPYLODISCUS HIBERNICUS EHR.
+
+Valve irregularly orbicular; costae, 40-60, about 2 in 10 [mu], wide at the
+margin and attenuated toward the centre which is somewhat quadrate; the
+radials rough with minute apiculi.
+
+Pensauken, N. J., artesian well.
+
+Pl. 37, Fig. 5.
+
+
+
+{131}APPENDIX
+
+
+COLLECTION AND PREPARATION OF DIATOMS
+
+It is assumed that every student of the Diatomaceae has a general knowledge
+of the collection, preparation, mounting and examination of material. For
+the novice, however, the following methods, used by the author for many
+years, may be of service.
+
+_Collection of Fresh-water Material._--The yellow film on the inside of
+aquaria always contains small species. Stems of water-plants near the
+shores of ponds and the submerged roots, the brownish coating of rocks in
+streams and water-falls, fountains, and water-troughs, are prolific. At all
+times of the year, some diatoms may be found in a thin layer upon the mud
+of rivers or creeks. In the spring, brown patches of mud, filled with
+bubbles, floating near the shore in ponds, or coming down with the current
+in rivers, are rich in various forms. Within the limits assigned to our
+district, I have made collections in the following localities: Schuylkill
+River, including the region near Fairmount Dam, several reservoirs and the
+water-supply; the Wissahickon and Fairmount Park, Darby, Crum and Ridley
+Creeks, the Neshaminy and the Brandywine; meadow pools and rivulets near
+the city; the upper Delaware, the Water Gap and numerous cascades
+northward; the Shawangunk Mountains and the Poconos; many parts of New
+Jersey along the coast; the Pine Barren region, the Hammonton, Atsion and
+Kirkwood Ponds and the swamps near Atco.
+
+In the collection of fresh-water material, it is well to be provided with a
+number of small bottles. Take a handful of the water-plants or algae, and
+squeeze the material into the bottles, or, lacking a bottle, wrap it in
+paper. With a small forceps it is possible to detach minute quantities of a
+pure gathering which may not need further preparation beyond burning to a
+red heat on the cover-glass before mounting. A malacca cane, with extending
+rod to which may be screwed a bottle, net, spoon or hook, is useful on a
+long trip. If it is impossible to separate the thin film of diatoms from
+the mud in the bed of streams, dip up the surface mud with one bottle,
+allow to settle a few minutes, then pour off the supernatant liquid, which
+will be comparatively free from sand, into another bottle. It must be
+confessed, however, that the mud in streams near Philadelphia contains a
+large quantity of fine mica which, in some instances, it is impossible to
+remove.
+
+_Collection of Marine Material._--Shell scrapings, the stomachs of fish,
+marine algae, especially the brown and red algae, the hulls of vessels, mud
+from anchors and dredgings, are all sources which may prove valuable. In
+the sand ripples, after the tide recedes, a yellowish-brown deposit will be
+noticed. This should be taken up carefully with a spoon and placed in a
+bottle; the sand will settle at once and a very pure gathering will be held
+in suspension in the water. Such collections may be made along the entire
+coast of New Jersey on sunny days in summer. In salt meadows near Absecon
+and Hackensack, large quantities of diatoms, including Pleurosigma, may be
+obtained in the yellow scum floating on the surface.
+
+_The Blue Clay Deposit._--The blue clay occurs as a pre- or post-glacial
+deposit in the bed of the ancient Delaware River, and, at depths varying
+usually from fifteen to forty feet below the surface, has been obtained
+from artesian wells at Pavonia, Pensauken and Gloucester, N. J., also at
+Port Penn on the Delaware, and especially from the dredgings {132}made by
+the removal of Smith's Island opposite the city. In the city proper, it may
+be stated briefly that material may be found in a stratum of very light
+blue clay at a depth varying from twenty to sixty feet in many places south
+of Arch St. east of Broad St., and also along the beds of ancient rivulets
+near Tioga St., at Sixteenth St., and in certain other places which were
+probably subject to tidal overflow. One of the best collections was made
+along the bank of the Schuylkill at the east end of Walnut St. Bridge, at a
+depth of thirteen feet below the surface. Excavations for the Reading
+Terminal and the Subway and several buildings, as the Bingham House, have
+furnished numerous specimens.
+
+_Cleaning the Material._--Some gatherings may be so pure as to be ready for
+mounting when treated with dilute alcohol and oil of cloves. If, when
+gathered, the diatoms are immersed in a saturated solution of picric acid
+for several days, they may be stained with carmine or methylene blue, or
+whatever may be required to emphasize the contents of the frustules,
+including the endochrome and the pyrenoids. After staining, pass as rapidly
+as expedient through the treatment with dilute alcohol and oil of cloves,
+and mount in benzol balsam, avoiding heat. A hot solution of mercuric
+bichloride is sometimes used for the preservation of the endochrome,
+although washing is needed before mounting. For the particular stain
+considered best for certain details of structure, it will be advisable to
+consult works on Micro-Chemistry or Heinzerling (_l. c._). The stains of
+most importance are carmine, methylene blue, haematoxylin, gold chloride
+and Bismarck brown.
+
+Whatever method may be used in staining, the identification of forms is
+impossible, in most cases, unless the valves are carefully cleaned and the
+cell-contents destroyed. For this purpose provide a casserole holding from
+five to eight ounces, an iron tripod stand with alcohol lamp, several
+six-inch test-tubes, preferably those with a standard base, fitted with
+pure rubber corks. Take the material as free from twigs, dead leaves, sand,
+and other matter as possible, place it in the casserole, and add about the
+same quantity of nitric acid. Boil for twenty minutes and then add about
+half a teaspoonful of powdered bichromate of potash, stirring with a glass
+rod. Then take a beaker-glass partly filled with water and pour into it
+slowly the liquid which has been allowed to cool a short time, whirling the
+casserole to cause the concentration of sand in the centre. Allow the
+material to settle for half an hour or longer, according to the amount of
+diatoms and their size. Pour off the water, add more water, and place in a
+test-tube. Repeat the decantation, shaking the test-tube, closed with a
+rubber cork, vigorously each time. From time to time whirl the diatoms in
+the casserole and throw away the sand collected in the centre. By repeating
+the decantation, shaking and whirling, the deposit will be found to consist
+almost entirely of diatoms. It may be necessary to repeat the boiling in
+the acid and bichromate. If, however, any detritus other than sand is
+noted, boil in sulphuric acid and add from time to time minute pinches of
+powdered chlorate of potash, being careful to protect the eyes by holding a
+piece of glass before them; otherwise the explosions which occur are likely
+to throw some of the boiling acid into the eyes and destroy the sight. The
+material, when clean, should be white or, in the case of Synedra,
+yellowish. It is quite easy to construct a box fitted with the proper
+apparatus for boiling and provided with a glass door for observation, and a
+method of introducing the chlorate of potash through a small aperture or
+tube. The box may be placed in the garden or fastened outside of a window
+so that the poisonous fumes may be carried off.
+
+An excellent method, in the case of larger forms, is to boil the material
+already cleaned by the acid in water to which a few shavings of coarse
+brown soap are added. The difference in density will hold in suspension any
+flocculent matter, and while many of the smaller {133}forms will not
+settle, the others will be perfectly cleaned. When satisfied with the
+cleaning, preserve the stock material in part alcohol and, in using, pour
+into a smaller bottle the amount required, replace the dilute alcohol with
+distilled water, and mount as directed. It often happens that gatherings
+are made consisting almost entirely of sand. Attempts at cleaning in the
+usual way will cause the loss of nearly all of the diatoms. In this case,
+after the material has been treated with acid until nothing remains but
+sand and a few diatoms, the mechanical finger must be used.
+
+In the cleaning of marine deposits, various methods may be required. In the
+case of partly siliceous species, washing in pure water repeatedly is all
+that can be done. The larger and heavier diatoms may be separated from the
+sand by elutriation or by whirling in a casserole, by rocking in a shallow
+dish the shape of a watch crystal, or by pouring slowly over a strip of
+plate-glass at least two feet in length inclined at an angle of thirty
+degrees. The sand will cling to the glass, while the greater portion of the
+diatoms will run off. Where particles of shells or foraminifera are
+present, a preliminary boiling in hydrochloric acid is advisable. In all
+marine gatherings, the salt should first be washed out before proceeding
+with the cleaning.
+
+For hardened masses of clay and for fossil deposits, it is necessary to
+boil in carbonate of soda and follow with the acid treatment. Citric acid
+and acetate of potash used alternately in boiling may be tried. Soaking for
+a time in acetate of potash and allowing the material to deliquesce for a
+week before further process, has proved successful in some instances. The
+repetition of several methods and the gentle breaking of the harder masses
+with the point of a needle will disintegrate almost any diatomaceous earth,
+but, as a last resort for refractory deposits, boil in pure water, add a
+piece of caustic potash about the size of a pea, continue the boiling not
+more than thirty seconds longer, and pour instantly into dilute
+hydrochloric acid; otherwise the diatoms will be destroyed. Afterwards
+proceed with the usual treatment.
+
+_Slides and Covers._--Take half an ounce of No. 1 covers, circles, and
+place them in a wide-mouthed bottle. Add a portion of the following mixture
+(Dr. Carl Seiler's formula):
+
+  Bichromate of potash    2 oz.
+  Sulphuric acid          3 fl. oz.
+  Water                   25 fl. oz.
+
+Shake the bottle in order that the surfaces of the covers may be fully
+exposed to the action of the acid, and set aside for several hours. Decant
+the solution, add water repeatedly until all traces of the mixture are
+removed, and keep the circles in the bottle in fifty-per cent. alcohol.
+When needed, take out a circle with forceps and dry on a linen cloth.
+
+The slides may be treated in the same way, or they may be easily prepared
+by immersion in a solution of washing soda, and then washed and dried. This
+process may be used in cleaning the balsam or styrax from old slides.
+
+_Preparation of Strewn Mounts._--Place several covers on the mounting
+stand. With a dipping tube, cover each circle with distilled water, and add
+a small drop of the prepared diatoms, being careful to avoid any vibration
+of the stand. Heat the stand until small bubbles begin to appear, remove
+the lamp, and allow the water to evaporate. If the above method is
+carefully followed, the diatoms will be deposited in an even layer,
+provided the material is not too dense. Take a slide, centre it, and place
+a small amount of styrax on the centre. Invert the prepared cover, and
+gently place it upon the styrax. Heat the slide {134}on the mounting stand
+until the styrax bubbles and then allow to cool. If bubbles still remain,
+heat again until they disappear. It is well to mount several slides more
+than required, as some may be imperfect.
+
+_Preparation of Selected Mounts._--Take a slide, place a minute quantity of
+beeswax on two places at a distance apart nearly equal to the diameter of
+the cover used. Place a cover on the wax and press it down flat, or
+sufficiently to keep it in position. Dip a fine needle into the following
+cement:
+
+  Glacial acetic acid    12 drachms
+  Gelatine                2 drachms
+  Alcohol                 1 drachm
+
+This is made by adding the acid to the gelatine in a water-bath and then
+the alcohol, and filtering. Apply the moistened needle to the centre of the
+cover and spread as small a quantity as possible in a thin layer. Now place
+the slide upon the turn table, centre it with respect to the position of
+the gelatine, and with the finest sable brush draw a circle about a tenth
+of an inch in diameter around the gelatine in water-color (Windsor), blue
+or vermilion, or in India ink. Instead of the water-color, a circle of
+tin-foil the size of the cover and pierced with a hole in the centre may be
+used, but the colored circle is to be preferred, as, when brought into
+view, it indicates exactly the focus required for observing the diatom.
+
+The bottle containing the cleaned material, which has been kept in water
+and alcohol, should be refilled with distilled water and well shaken, when
+a small portion may be taken up with a dipping tube and evenly distributed
+over a portion of a slide and then dried. By the use of a mechanical
+finger, fitted with a small piece of finely spun glass attached by wax to
+the holder of the finger, when the microscope is focussed until the glass
+thread touches the diatom selected, it will adhere to the thread. Raise the
+body of the microscope, remove the slide containing the spread material, or
+move it to another part of the stage, and place the slide with the prepared
+cover in the same position. Now carefully lower the body-tube of the
+instrument until the diatom rests upon the gelatine, breathe gently upon
+it, remove the cover from the slide, invert it over another slide
+containing a drop of styrax and proceed by heating to mount as before. The
+size of the diatom, the amount of gelatine, and several other factors, will
+enter into the question of success or failure. I have, however, employed
+the above method and have mounted thousands of slides of selected diatoms
+successfully. It is necessary to avoid any air current which will cause the
+diatom to fall from the thread. On very cold days the glass thread
+sometimes becomes electrified and the diatoms will not stick; on sultry
+days in August in our locality the diatoms will stick too closely.
+
+By the same method, slides of arranged diatoms can be made using a glass
+circle properly marked with lines in the eye-piece. Care should be taken to
+use glass threads more or less in proportion to the size of the diatoms. A
+cat's whisker is preferred by some to the glass thread. It has the
+advantage of not breaking, but unless it is quite short it is too flexible.
+If the point of the thread becomes covered with gelatine, lower it into a
+minute drop of water upon a separate slide, and by moving it about it will
+be cleaned. The diatom itself may be washed in the same way, if it is not
+too small.
+
+_Instruments Required._--For collecting, in order to determine the quality
+of the find, any simple lens of fifteen to twenty diameters is sufficient.
+A Stanhope is quite useful {135}although difficult to obtain, while an
+achromatic triplet of sufficient power will probably be all that is
+necessary. For selecting with the mechanical finger, an objective of
+two-thirds-inch focus is the most convenient, but for determining species a
+one-fifth-inch is needed, an immersion objective being essential for minute
+forms.
+
+No particular form of microscope is required. Any instrument having
+standard parts, inclination of the body to the axis, a sub-stage condenser
+and movable stage, will prove serviceable in nearly all investigations. For
+critical work, measurement of striae and location of specimens on the
+slide, the large models of Bausch and Lomb leave nothing to be desired. One
+smaller instrument may be used for rapid examination and for selection with
+the mechanical finger. If the stage is supplied with a vernier, the diatoms
+can be located rapidly and recorded for future reference. The Zentmayer
+Army Hospital stand with mechanical stage is excellent. The Continental
+stands, convenient for laboratory work, especially in the examination of
+bacteria, are not so serviceable as the larger stands of American and
+English make. The stand especially designed by Dr. Henri Van Heurck, the
+celebrated Belgian naturalist, is, without doubt, admirably suited to the
+investigation of the Diatomaceae. In the form of the Circuit Stage as made
+by Watson and Sons, of London, supplied with proper condenser and
+mechanical stage with vernier attachment, it has been used in the
+preparation of the present work with much satisfaction.
+
+The drawings have all been made with an Abbe camera lucida, a 3 mm.
+objective and a No. 10 eye-piece, producing a magnification of about 800
+diameters. All illustrations are from actual specimens in my cabinet or, in
+a few instances, from slides sent me by friends. In the measurement of
+striae and puncta, the number in ten microns is stated, and will be found
+to be approximately correct in most of the drawings, except when the number
+is in excess of twenty in ten microns, in which case it is impossible to
+represent the markings accurately on figures of the magnification adopted.
+All drawings are from specimens in this locality, except in a few cases
+mentioned in the text.
+
+
+
+
+{137}INDEX
+
+
+(SYNONYMS IN ITALICS)
+
+
+
+                                                PAGE
+  Achnanthes,                                     58
+    brevipes Ag.,                                 59
+    coarctata (Breb.) Grun.,                      59
+    danica (Floegel) Grun.,                       60
+    exigua Grun.,                                 59
+    inflata (Kuetz.) Grun.,                       59
+    lanceolata (Breb.) Grun.,                     59
+    linearis forma curta H.L.S.,                  59
+    longipes Ag.,                                 58
+    subsessilis Kuetz.,                           59
+
+  Actinella,                                      54
+    punctata Lewis,                               54
+
+  Actinocyclus,                                   26
+    barkleyi var. aggregata Rattr.,               27
+    ellipticus var. delawarensis n. var.,         27
+    moniliformis Ralfs,                           27
+
+  Actinoptychus,                                  24
+    _cellulosa_ Ehr.,                             24
+    heliopelta Grun. var.?,                       25
+    _omphalopelta_ Ehr.,                          24
+    undulatus (Kuetz.) Ralfs,                     24
+    vulgaris var. interrupta n. var.,             24
+
+  Amphipleura,                                    78
+    pellucida Kuetz.,                             78
+    rutilans (Trentepohl) Cl.,                    78
+
+  Amphiprora,                                     68
+    alata Kuetz.,                                 68
+    conspicua Grev.,                              68
+    _lepidoptera_ Greg.,                          69
+    ornata Bail.,                                 68
+    paludosa Wm. Sm.,                             68
+    pulchra Bail.,                                68
+
+  _Amphitetras_,
+    _antediluviana_ Ehr.,                         32
+    _tessellata_ Shad.,                           32
+
+  Amphora,                                        65
+    acuta Greg.,                                  66
+    angusta var. eulensteinii Grun.,              67
+    _aponina_ Kuetz.,                             66
+    arenaria Donk.,                               67
+    areolata Grun.,                               66
+    coffaeiformis (Ag.) Kuetz.,                   66
+    crassa Greg.,                                 65
+    _eulensteinii_ A.S.,                          67
+    gigantea var. fusca A.S.,                     65
+    _insecta_ Grun.,                              69
+    laevis Greg.,                                 66
+    lineolata Ehr.,                               66
+    _mucronata_ H.L.S.,                           69
+    obtusa Greg.,                                 67
+    ocellata var. cingulata Cl.,                  67
+    ostrearia Breb.,                              66
+    ovalis (Breb.) Kuetz.,                        65
+      var. libyca (Ehr.) Cl.,                     65
+      var. pediculus (Kuetz.) Cl.,                65
+    _plicata_ Greg.,                              66
+    _porcellus_ Kitton,                           66
+    proteus Greg.,                                65
+    _quadrata_ Breb.,                             66
+    robusta Greg.,                                65
+    _salina_ Wm. Sm.,                             66
+    _vitraea_ Cl.,                                66
+
+  Anomoeoneis,                                    80
+    follis (Ehr.) Cl.,                            80
+    serians Breb.,                                80
+    sphaerophora (Kuetz.) Cl.,                    80
+
+  Anorthoneis,                                    56
+    excentrica (Donk.) Grun.,                     56
+
+  Asterionella,                                   50
+    formosa Hass.,                                50
+    inflata Heib.,                                50
+
+  Attheya,                                        38
+    decora West,                                  38
+
+  Aulacodiscus,                                   26
+    argus (Ehr.) A.S.,                            26
+
+  Auliscus,                                       28
+    caelatus Bail.,                               29
+    pruinosus Bail.,                              28
+    punctatus Bail.,                              28
+    sculptus (Wm. Sm.) Ralfs,                     29
+    _spinosus_ Christian,                         29
+
+  Auricula,                                       69
+    _insecta_ (Grun.) Cl.,                        69
+    mucronata (H.L.S.) Per.,                      69
+
+  _Bacillaria_,                                  119
+    _paradoxa_ Gmelin,                           119
+
+  Biddulphia,                                     31
+    alternans (Bail.) V. H.,                      33
+    antediluviana (Ehr.) V. H.,                   32
+    biddulphiana (Smith),                         31
+    favus (Ehr.) V. H.,                           31
+    granulata Roper,                              32
+    laevis Ehr.,                                  33
+    _pulchella_ Gray.,                            31
+    reticulum (Ehr.),                             33
+    rhombus (Ehr.) Wm. Sm.,                       32
+    smithii (Ralfs) V. H.,                        32
+    turgida (Ehr.) Wm. Sm.,                       32
+
+  Brebissonia,                                    79
+    boeckii (Kuetz.) Grun.,                       79
+    palmerii n. sp.,                              80
+
+  Caloneis,                                       81
+    brevis var. vexans Grun.,                     82
+    formosa (Greg.) Cl.,                          82
+    liber (Wm. Sm.) Cl.,                          81
+    permagna (Bail.) Cl.,                         82
+      var. lewisiana n. var.,                     82
+    powellii (Lewis) Cl.,                         83
+    silicula (Ehr.) Cl.,                          81
+      var. inflata (Grun.) Cl.,                   81
+    trinodis (Lewis),                             81
+    wardii Cl.,                                   82
+
+  Campylodiscus,                                 129
+    _argus_ Bail.,                               130
+    echeneis Ehr.,                               130
+    hibernicus Ehr.,                             130
+
+  _Cerataulus_
+    _smithii_ Ralfs,                              32
+    _turgidus_ Ehr.,                              32
+
+  Cocconeis,                                      57
+    dirupta Greg.,                                58
+    pediculus Ehr.,                               57
+    pellucida Grun.,                              58
+    placentula Ehr.,                              57
+      var. lineata (Ehr.) V. H.,                  58
+    scutellum Ehr.,                               57
+      var. ornata Grun.,                          57
+
+  _Cocconema_
+    _asperum_ Ehr.,                               61
+
+  _Colletonema_
+    _neglectum_ Thwaites,                         95
+    _vulgaris_ Thwaites,                          77
+
+  _Conferva_
+    _biddulphiana_ Smith,                         31
+    _flocculosa_ Roth,                            36
+    _moniliformis_ Mueller,                       16
+    _nummuloides_ Dillw.,                       1617
+    _rutilans_ Trentepohl,                        78
+
+  Coscinodiscus,                                  21
+    argus Ehr.,                                   23
+    asteromphalus Ehr.,                           23
+      var. omphalantha Grun.,                     23
+    biangulatus A. S.,                            23
+    denarius A. S.,                               22
+    excentricus Ehr.,                             21
+      var. perpusilla Grun.,                      21
+    lewisianus Grev.,                             24
+    lineatus Ehr.,                                21
+    marginatus Ehr.,                              22
+    _minor_ Wm. Sm.,                              14
+    nitidulus Grun.,                              21
+    nitidus Greg.,                                21
+    oculus-iridus Ehr.,                           23
+    polyacanthus Grun.,                           22
+    radiatus Ehr.,                                23
+    _striatus_ Kuetz.,                            19
+    subaulacodiscoidalis Rattr.,                  23
+    subtilis Ehr.,                                21
+    velatus Ehr.,                                 22
+
+  _Creswellia_
+    _turris_ Grev.,                               18
+
+  Cyclotella,                                     19
+    antiqua Wm. Sm.,                              20
+    comta (Ehr.) Kuetz.,                          20
+    _dallasiana_ Wm. Sm.,                         19
+    _kuetzingiana_ Wm. Sm.,                       19
+    meneghiniana Kuetz.,                          19
+      var. stelligera Cl. and Grun.,              20
+      var. stellulifera Cl. and Grun.,            20
+    operculata (Ag.) Kuetz.,                      20
+    _scotica_ Kuetz.,                             18
+    striata (Kuetz.) Grun.,                       19
+    stylorum (Br.?) V. H.,                        20
+
+  Cymatopleura,                                  129
+    elliptica (Breb.) Wm. Sm.,                   129
+    marina Lewis,                                129
+    solea (Breb.) Wm. Sm.,                       129
+
+  Cymbella,                                       60
+    affinis Kuetz.,                               61
+    amphicephala Naegeli,                         61
+    aspera (Ehr.) Cl.,                            61
+    cistula (Hempr.) Kirchn.,                     62
+    cuspidata Kuetz.,                             60
+    cymbiformis (Kuetz.) Breb.,                   62
+    ehrenbergii Kuetz.,                           60
+    excisa (Kuetz.) De Toni,                      61
+    _gastroides_ Kuetz.,                          61
+    gracilis (Rab.) Cl.,                          64
+    heteropleura (Ehr.) Kuetz.,                   60
+    lacustris (Ag.) Cl.,                          64
+    lanceolata (Ehr.) Kirchn.,                    62
+    mexicana (Ehr.) A. S.,                        62
+    naviculiformis Auerswald,                     60
+    parva (Wm. Sm.) Cl.,                          61
+    philadelphica n. sp.,                         63
+    prostrata (Berk.) Cl.,                        63
+    rhomboidea n. sp.,                            63
+    sinuata Greg.,                                61
+    triangulum (Ehr.) Cl.,                        63
+    tumida (Breb.) V. H.,                         62
+    turgida (Greg.) Cl.,                          63
+      var.?,                                      63
+    ventricosa Kuetz.,                            62
+
+  Diatoma,                                        41
+    anceps (Ehr.) Kirchn.,                        42
+    _arcuatum_ Lyng.,                             35
+    _biddulphianum_ Ag.,                          31
+    hiemale (Lyng.) Heib.,                        42
+    _marinum_ Lyng.,                              37
+    vulgare Bory.,                                42
+      var. elongatum (Ag.),                       42
+      var. grande (Wm. Sm.) Grun.,                42
+
+  Dictyoneis,                                     78
+    marginata var. commutata Cl.,                 79
+      var. maxima n. var.,                        79
+      var. typica Cl.,                            78
+
+  Dimerogramma,                                   46
+    marinum (Greg.) Ralfs,                        46
+    minus (Greg.) Ralfs,                          47
+    _sinuatum_ Thwaites,                         119
+    surirella (Ehr.) Grun.,                       46
+
+  Diploneis,                                      84
+    campylodiscus (Grun.) Cl.,                    86
+    crabro Ehr. var.?,                            85
+      var. expleta (A. S.) Cl.,                   85
+      var. pandura (Breb.) Cl.,                   85
+      var. pandurella Cl.?,                       85
+    elliptica (Kuetz.) Cl.,                       84
+      var. _minutissima_ Grun.,                   85
+    excentrica n. sp.,                            85
+    fusca var. delicata (A. S.) Cl.,              85
+    gemmata (Grev.) Cl.,                          86
+    gruendleri (A. S.) Cl.,                       85
+    oculata (Breb.) Cl.,                          86
+    puella (Schum.) Cl.,                          85
+    smithii (Breb.) Cl.,                          84
+
+  Ditylum,                                        30
+    intricatum (West) Grun.,                      30
+
+  _Echinella_
+    _circularis_ Grev.,                           40
+    _flabellata_ Carm.,                           39
+    _paradoxa_ Lyng.,                             39
+
+  Encyonema,                                      62
+
+  Epithemia,                                     111
+    argus Kuetz.,                                111
+      var.?,                                     111
+    _gibba_ var. _ventricosa_ Kuetz.,            113
+    gibberula var. producta Grun.,               112
+    _marina_ Donk.,                              114
+    muelleri A. S.?,                             111
+    musculus Kuetz.,                             112
+      var. constricta (Breb.) V. H.,             112
+    _succincta_ Breb.,                           112
+    turgida (Ehr.) Kuetz.,                       111
+    zebra var. proboscidea (Kuetz.) Grun.,       112
+
+  Eunotia,                                        51
+    bactriana Ehr.,                               54
+    biceps Ehr.,                                  53
+    bidentula Wm. Sm.,                            54
+    _bigibba_ Greg.,                              53
+    formica Ehr. var.?,                           54
+    gracilis (Ehr.) Rab.,                         51
+    hemicyclus (Ehr.) Ralfs,                      53
+    _incisa_ Greg.,                               52
+    luna Ehr.,                                    52
+    lunaris (Ehr.) Grun.,                         53
+    major (Wm. Sm.) Rab.,                         51
+    nymanniana Grun.,                             51
+    pectinalis (Kuetz.),                          52
+      var. solierolii (Kuetz.),                   52
+      var. undulata Ralfs,                        52
+      var. ventricosa Grun.,                      52
+    praerupta Ehr.,                               53
+      var. bidens Grun.,                          53
+    robusta Ralfs,                                53
+    veneris Kuetz.,                               52
+
+  Eunotogramma,                                   33
+    laeve Grun.,                                  33
+
+  Euodia,                                         34
+    gibba Bail.,                                  34
+
+  Eupodiscus,                                     28
+    _argus_ (Ehr.) Wm. Sm.,                       26
+    radiatus Bail.,                               28
+    _radiatus_ Wm. Sm.,                           32
+
+  Fragilaria,                                     44
+    arctica Grun.,                                44
+    capucina var. mesolepta Rab.,                 45
+    construens (Ehr.) Grun.,                      45
+    harrisonii (Wm. Sm.) Grun.,                   45
+    linearis Cstr.,                               45
+    parasitica (Wm. Sm.),                         45
+    undata Wm. Sm.,                               44
+    virescens Ralfs,                              44
+
+  Frustulia,                                      77
+    _acuminata_ Kuetz.,                           76
+    interposita (Lewis) De Toni,                  78
+    lewisiana (Grev.) De Toni,                    77
+    rhomboides (Ehr.) De Toni,                    77
+      var. amphipleuroides Grun.,                 77
+      var. saxonica Rab.,                         77
+    vulgaris (Thwaites) De Toni,                  77
+
+  Gaillonella,                                    16
+    _crenulata_ Ehr.,                             15
+    _granulata_ Ehr.,                             15
+    _moniliformis_ Bail.,                         16
+    nummuloides (Dillw.) Bory.,                   16
+    _sulcata_ Ehr.,                               15
+
+  _Gloeonema_,                                    63
+    _triangulum_ Ehr.,                            63
+
+  Gomphoneis,                                     70
+    herculaneum (Ehr.) Cl.,                       70
+    mamilla (Ehr.) Cl.,                           70
+
+  Gomphonema,                                     70
+    acuminatum,                                   71
+      var. coronata (Ehr.) Cl.,                   71
+      var. trigonocephala (Ehr.) Cl.,             71
+      var. turris (Ehr.) Cl.,                     71
+      var. turris (Ehr.) Cl.?,                    71
+    aequale Greg.,                                72
+    angustatum Kuetz.,                            72
+    augur Ehr.,                                   72
+    brasiliense var. demerarae Grun.?,            73
+    capitatum Ehr.,                               72
+    capitatum var. herculaneum Ehr.,              70
+    constrictum Ehr.,                             72
+    geminatum Lyng.,                              71
+    _insigne_ Greg.,                              71
+    intricatum Kuetz.,                            72
+    lanceolatum var. insignis (Greg.) Cl.,        71
+    montanum Schum.,                              71
+    olivaceum Lyng.,                              73
+    parvulum var. micropus (Kuetz.) Cl.,          73
+    sarcophagus Greg.,                            72
+    sphaerophorum Ehr.,                           72
+    _subclavatum_ var. _montana_ Schum.,          71
+    _tinctum_ Ag.,                                40
+    ventricosum Greg.,                            73
+
+  Grammatophora,                                  36
+    angulosa var. hamulifera (Kuetz.) Grun.,      37
+    islandica Ehr.,                               37
+    marina (Lyng.) Kuetz.,                        37
+      var. subtilissima (Bail.) V. H.,            37
+    serpentina Ralfs,                             37
+    _subtilissima_ Bail.,                         37
+
+  Gyrosigma,                                      75
+    acuminatum (Kuetz.) Cl.,                      76
+    _attenuatum_ (Kuetz.) Cl.,                    75
+    balticum (Ehr.) Cl.,                          75
+      var. _similis_ (Grun.) Cl.,                 76
+    fasciola (Ehr.) Cl.,                          77
+    hippocampus (Ehr.),                           75
+    kuetzingii (Grun.) Cl.,                       76
+    parkeri var. stauroneioides Grun.,            75
+    prolongatum (Wm. Sm.) Cl.,                    76
+    scalproides (Rab.) Cl.,                       76
+    simile (Grun.),                               76
+    spencerii var. nodifera Grun.,                76
+    strigilis (Wm. Sm.) Cl.,                      76
+
+  Hantzschia,                                    113
+    amphioxys (Ehr.) Grun.,                      113
+      var. major Grun.,                          114
+    marina (Donk.) Grun.,                        114
+    virgata (Roper) Grun.,                       114
+
+  _Himantidium_
+    _pectinate_ Kuetz.,                           52
+
+  Homoeocladia,                                  123
+    filiformis Wm. Sm.,                          123
+
+  Hyalodiscus,                                    17
+    radiatus var. arctica Grun.,                  17
+    scoticus (Kuetz.) Grun.,                      18
+    stelliger Bail.,                              17
+    subtilis Bail.,                               18
+
+  Licmophora,                                     38
+    baileyi (Ehr.) Grun.,                         40
+    ehrenbergii (Kuetz.) Grun.,                   40
+    flabellata (Carm.) Ag.,                       39
+    gracilis (Ehr.) Grun.,                        39
+      var. elongata (Kuetz.) De Toni,             39
+    lyngbyei (Kuetz.) Grun.,                      40
+    ovulum Mer.,                                  39
+    paradoxa (Lyng.) Ag.,                         39
+    _splendida_ Wm. Sm.,                          39
+    tincta (Ag.) Grun.,                           40
+
+  Lysigonium,                                     16
+    moniliforme (Muell.) Link,                    16
+    _nummuloides_ (Lyng.) O'Meara,                17
+    varians (Ag.) De Toni,                        17
+
+  Mastogloia,                                     86
+    angulata Lewis,                               87
+    apiculata Wm. Sm.,                            87
+    _braunii_ Grun.,                              87
+    elegans Lewis,                                87
+    exigua Lewis,                                 87
+    kinsmanii Lewis,                              87
+    lanceolata Thwaites,                          87
+    smithii Thwaites,                             87
+
+  Meloseira,                                      14
+    _borreri_ Grev.,                              17
+    crenulata (Ehr.) Kuetz.,                      15
+    distans (Ehr.) Kuetz.,                        14
+    _gowenii_ A. S.,                              15
+    granulata (Ehr.) Ralfs,                       15
+    _nivalis_ Wm. Sm.,                            14
+    _nummuloides_ Ag.,                            16
+    roeseana Rab.,                                15
+      var. epidendron (Ehr.) Grun.,               15
+    sulcata Kuetz.,                               15
+    undulata (Ehr.) Kuetz.,                       15
+    _varians_ Ag.,                                17
+
+  Meridion,                                       40
+    circulare (Grev.) Ag.,                        40
+    _constrictum_ Ralfs,                          41
+
+  _Micromega_
+    _ramosissimum_ Ag.,                           95
+
+  Navicula,                                       89
+    _affinis_ Ehr.,                               83
+    americana Ehr.,                               98
+    _amphibola_ Cl.,                              92
+    _amphigomphus_ Ehr.,                          83
+    anglica Ralfs,                                96
+    _angulata_ Quek.,                             74
+    ardua Mann,                                   96
+    _arenaria_ Donk.,                             95
+    atomus Naegeli,                              100
+    bacillum Ehr.,                                98
+    _baltica_ Ehr.,                               75
+    brasiliensis var. bicuneata Cl., forma
+      constricta,                                 92
+    crucigera (Wm. Sm.) Cl.,                     100
+    cryptocephala Kuetz.,                         97
+    cuspidata Kuetz.,                            100
+      var. ambigua (Ehr.) Cl.,                   100
+    cyprinus (Wm. Sm.),                           95
+    delawarensis Grun.,                           92
+    dicephala Wm. Sm.,                            96
+    _digito-radiata_ var. _cyprinus_ (Ehr.?) Wm.
+      Sm.,                                        95
+    elegans Wm. Sm.,                             101
+      var. cuspidata Cl.,                        101
+    _firma_ Kuetz.,                               84
+    _fischeri_ A. S.,                             90
+    _follis_ Ehr.,                                80
+    fuchsii Pant.,                                91
+    gastrum Ehr.,                                 96
+    _gigas_ A. S.,                               103
+    _globiceps_ Lagerstedt,                       96
+    gracilis var. schizonemoides (Ehr.) V. H.,    95
+    grevillei (Ag.) Cl.,                          99
+    hasta Pant.,                                  97
+      var. punctata n. var.,                      97
+    hennedyi Wm. Sm.,                             93
+      var. circumsecta Grun.,                     93
+      var. manta A. S.,                           93
+    _hippocampus_ Ehr.,                           75
+    _hitchcockii_ Ehr.,                           84
+    humerosa Breb.,                               91
+      var. _elongata_ Pant.,                      91
+      var. _fuchsii_ (Pant.) Cl.,                 91
+    humilis Donk.,                                96
+    _hungarica_ var. _capitata_ (Ehr.) Cl.,       96
+    inflexa Greg.,                                96
+    integra Wm. Sm.,                              99
+    _interposita_ Lewis,                          78
+    _iridis_ Ehr.,                                84
+    irrorata Grev.,                               93
+    lacustris Greg.,                              92
+    lanceolata var. arenaria (Donk.) Cl.,         95
+    latissima Greg.,                              90
+      var. elongata (Pant.) Cl.,                  91
+    libellus Greg.,                               99
+    _limosa_ Donk.,                               81
+    longa (Greg.) Ralfs,                          97
+    lyra Ehr.,                                    93
+      var. dilatata A. S.,                        93
+      var. ehrenbergii Cl.,                       93
+      var.?,                                      93
+    maculata (Bail.) Cl.,                         90
+    _marginata_ Lewis,                            78
+    _marina_ Ralfs,                               92
+    minima Grun.,                                 98
+    _mormonorum_ Grun.,                          107
+    mutica Kuetz.,                                97
+    oblonga Kuetz.,                               97
+    _oculata_ Breb.,                              86
+    palpebralis Breb.,                           101
+    pennata A. S.,                                96
+    peregrina Ehr.,                               94
+    pinnata Pant.?,                               96
+    placenta Ehr.,                                94
+    praetexta Ehr.,                               92
+    _producta_ Wm. Sm.,                           83
+    punctata var. asymmetrica Lagerstedt,         92
+    punctulata Wm. Sm.,                           92
+    pupula var. bacillarioides Grun.,             98
+    pusilla Wm. Sm.,                              91
+      var. subcapitata n. var.,                   91
+    pygmaea Kuetz.,                               94
+    radiosa Kuetz.,                               94
+    ramosissima (Ag.) Cl.,                        95
+    _rectangulata_ Greg.,                        110
+    reinhardtii Grun.,                            95
+    rhyncocephala Kuetz.,                         97
+    salinarum Grun.,                              95
+    semen Ehr.,                                   98
+    _silicula_ Ehr.,                              81
+    _socialis_ Palmer,                           104
+    spectabilis var. emarginata Cl.,              94
+    _sphaerophora_ Kuetz.,                        80
+    spicula (Hickie) Cl.,                        100
+    _trochus_ Kuetz.,                             80
+    tumida (Breb.) Cl.,                           99
+    viridula var. rostellata Kuetz.,              95
+    yarrensis Grun.,                             101
+
+  Neidium,                                        83
+    affine (Ehr.) Pfitzer,                        83
+      var. amphirhyncus (Ehr.) Cl.,               83
+      var. genuina forma maxima Cl.,              83
+      var. genuina forma minor Cl.,               83
+    amphigomphus (Ehr.) Pfitzer,                  83
+    hitchcockii (Ehr.) Cl.,                       84
+    iridis (Ehr.) Cl.,                            84
+    productum (Wm. Sm.) Cl.,                      83
+
+  Nitzschia,                                     114
+    acicularis (Kuetz.) Wm. Sm.,                 123
+    acuminata (Wm. Sm.) Grun.,                   117
+    amphibis Grun.,                              122
+    amphioxys Wm. Sm.,                           114
+    apiculata (Greg.) Grun.,                     117
+    bilobata Wm. Sm.,                            118
+    circumsuta (Bail.) Grun.,                    118
+    clausii Hantzsch,                            121
+    communis Rab.,                               122
+    compressa Bail.,                             116
+      var. minor H. L. S.,                       116
+    _curvula_ Wm. Sm.,                           121
+    dissipata (Kuetz.) Grun.,                    120
+    dubia Wm. Sm.,                               118
+    epithemioides Grun.,                         118
+    fluminensis Grun.,                           120
+    granulata Grun.,                             116
+    insignis Greg.,                              119
+    intermedia Hantzsch,                         122
+    linearis (Ag.) Wm. Sm.,                      122
+    litoralis var. delawarensis Grun.,           118
+    longissima (Breb.) Ralfs,                    123
+      forma parva V. H.,                         123
+    macilenta Greg.,                             120
+    navicularis (Breb.) Grun.,                   116
+    obtusa Wm. Sm.,                              121
+      var. flexella H. L. S.,                    121
+      var. scalpelliformis Grun.,                121
+    palea (Kuetz.) Wm. Sm.,                      122
+    panduriformis Greg.,                         117
+      var. minor Grun.,                          117
+    _paradoxa_ (Gmelin) Grun.,                   119
+    paxillifer (O. F. Mueller) Heib.,            119
+    plana Wm. Sm.,                               117
+    _punctata_ (Wm. Sm.) Grun.,                  116
+    reversa Wm. Sm.,                             123
+    scalaris (Ehr.) Wm. Sm.,                     119
+    sigma (Kuetz.) Wm. Sm.,                      121
+      var. _curvula_ (Wm. Sm.) De Toni,          121
+    sigmatella Greg.,                            121
+    _sinuata_ var. _tabellaria_ (Grun.) V. H.,   119
+    spathulata Breb.,                            120
+    spectabilis var. americana Grun.,            122
+    tabellaria Grun.,                            119
+    tryblionella Hantzsch,                       116
+    vermicularis (Kuetz.) Hantzsch,              120
+
+  _Odontidium_
+    _parasiticum_ Wm. Sm.,                        45
+    _tabellaria_ Wm. Sm.,                         45
+
+  Opephora,                                       43
+    pacifica (Grun.) Petit,                       43
+    pinnata var. lanceolata n. var.,              44
+    schwartzii (Grun.) Petit,                     43
+
+  _Orthosira_
+    _orichalcea_ Wm. Sm.,                         15
+    _punctata_ Wm. Sm.,                           15
+    _spinosa_ Grev.,                              15
+
+  _Paralia_
+    _marina_ Heib.,                               15
+    _sulcata_ (Ehr.) Cl.,                         15
+
+  Pinnularia,                                    101
+    acrosphaeria (Breb.) Cl.,                    108
+      var. turgidula Grun.?,                     108
+    aestuarii Cl.,                               105
+    appendiculata (Ag.) Cl.,                     106
+    blandita n. sp.,                             108
+    borealis Ehr.,                               109
+      var. scalaris (Ehr.) Cl.,                  109
+    braunii Grun.,                               106
+    brebissonii (Kuetz.) Cl.,                    107
+    cardinaliculus Cl.,                          107
+    _cyprinus_ Wm. Sm.,                           95
+    dactylus Ehr.,                               103
+      var. dariana (A. S.) Cl.,                  103
+      var. demerarae Cl.,                        103
+    divergens var. elliptica Grun.,              107
+    gentilis (Donk.) Cl.,                        103
+    gibba (Kuetz.) V. H.,                        109
+    _interrupta_ forma _stauroneiformis_ Cl.,    106
+    lata (Breb.) Wm. Sm.,                        109
+    legumen Ehr.,                                107
+      var.?,                                     107
+    leptosoma Grun.,                             105
+    major (Kuetz.) Wm. Sm.,                      102
+      var. pulchella n. var.,                    102
+    mesogongyla (Ehr.) Cl.,                      109
+    mesolepta Ehr.,                              105
+      var. stauroneiformis Grun.,                105
+    microstauron (Ehr.) Cl.,                     106
+    molaris (Grun.) Cl.,                         105
+    mormonorum Grun.,                            107
+    nobilis Ehr.,                                103
+    nodosa forma capitata Cl.,                   108
+    parva (Ehr.) Cl.,                            108
+    _permagna_ Bail.,                             82
+    polyonca (Breb.) Lewis,                      108
+    rectangulata (Greg.) Cl.,                    110
+    socialis (Palmer),                           104
+    stauroptera (Grun.) Cl.,                     110
+      var. interrupta forma stauroneiformis Cl., 110
+    stomatophora (Grun.) Cl.,                    109
+    subcapitata Greg.,                           105
+      var. paucistriata Grun.,                   106
+    tabellaria (Ehr.) Cl.,                       110
+    termes (Ehr.) A. S.,                         106
+      var. stauroneiformis V. H.,                106
+    trigonocephala Cl.,                          103
+    viridis Nitzsch,                             104
+      var. caudata n. var.,                      104
+      var. fallax Cl.,                           104
+      var.?,                                     104
+
+  Plagiogramma,                                   42
+    obesum Grev.,                                 43
+    pygmaeum Grev.,                               43
+    tessellatum Grev.,                            43
+    wallichianum Grev.,                           43
+
+  Pleurosigma,                                    73
+    aestuarii Breb.,                              74
+    _affine_ var. _fossilis_ Grun.,               74
+    angulatum (Quekett) Cl.,                      74
+    _balticum_ (Ehr.) Wm. Sm.,                    75
+    formosum Wm. Sm.,                             73
+    _hippocampus_ (Ehr.) Wm. Sm.,                 75
+    naviculaceum Breb.,                           74
+    _normanii_ var. _fossilis_ Grun.,             74
+    obscurum Wm. Sm.,                             74
+    rigidum Wm. Sm.,                              75
+    _simile_ Grun.,                               76
+    _spencerii_ var. _acutiuscula_ Grun.,         76
+      var. _kuetzingii_ Grun.,                    76
+    strigosum Wm. Sm.,                            74
+    virginiacum H. L. S.,                         74
+
+  Podocystis,                                    128
+    adriatica Kuetz.,                            129
+    _americana_ Bail.,                           129
+
+  _Podosira_
+    _hormoides_ Wm. Sm.,                          18
+    _maculata_ Wm. Sm.,                           17
+
+  _Podosphenia_
+    _baileyi_ (Edw.) Lewis,                       40
+    _ehrenbergii_ Kuetz.,                         40
+    _lyngbyei_ Kuetz.,                            40
+
+  Polymyxus,                                      25
+    coronalis L. W. Bail.,                        25
+
+  Pseudauliscus,                                  29
+    radiatus (Bail.) Rattr.,                      29
+    spinosus (Christian) Rattr.,                  29
+
+  Pyxidicula,                                     19
+    _compressa_ Bail.,                           116
+      var. _minor_ H. L. S.,                     116
+    cruciata Ehr.,                                19
+    _radiata_ O'Meara,                            17
+
+  Rhabdonema,                                     35
+    adriaticum Kuetz.,                            36
+    arcuatum (Lyng.) Kuetz.,                      35
+    minutum Kuetz.,                               36
+
+  Rhaphoneis,                                     46
+    amphiceros Ehr.,                              46
+      var. rhombica Grun.,                        46
+    belgica var. intermedia Grun.,                46
+
+  _Rhipidophora_
+    _elongata_ Kuetz.,                            39
+    _paradoxa_ Kuetz.,                            39
+
+  Rhoicosphenia,                                  56
+    curvata (Kuetz.) Grun.,                       56
+
+  Rhopalodia,                                    112
+    gibba (Kuetz.) Mueller,                      112
+    ventricosa (Kuetz.) Mueller,                 113
+
+  _Schizonema_
+    _cruciger_ Wm. Sm.,                          100
+    _dillwynii_ Wm. Sm.,                          78
+    _grevillei_ Ag.,                              99
+    _smithii_ Kuetz.,                             95
+
+  _Scoliopleura_
+    _tumida_ (Breb.) V. H.,                       99
+
+  Scoliotropis,                                   69
+    latestriata var. amphora Cl.,                 69
+
+  Stauroneis,                                     88
+    acuta Wm. Sm.,                                89
+    americana A. S.,                              89
+    anceps Ehr.,                                  88
+      var. amphicephala (Kuetz.) Cl.,             88
+      var. gracilis (Ehr.) Cl.,                   88
+    crucicula (Grun.) Cl.,                        89
+    _exilis_ Kuetz.,                              59
+    frickei var. angusta n. var.,                 88
+    legumen Ehr.,                                 89
+    _maculata_ Bail.,                             90
+    phoenicenteron Ehr.,                          88
+    salina Wm. Sm.,                               89
+    smithii Grun.,                                89
+    _spicula_ Hickie,                            100
+
+  _Staurosira_
+    _construens_ Ehr.,                            45
+
+  Stephanopyxis,                                  18
+    _appendiculata_ Ehr.,                         18
+    corona (Ehr.) Grun.,                          18
+    turris (Grev.) Ralfs,                         18
+
+  Striatella,                                     37
+    interrupta (Ehr.) Heib.,                      38
+    unipunctata (Lyng.) Ag.,                      38
+
+  Surirella,                                     124
+    amphioxys Wm. Sm.,                           124
+    anceps Lewis,                                128
+    angusta Kuetz.,                              127
+    arctissima A. S.,                            128
+    _bifrons_ Ehr.,                              124
+    biseriata (Ehr.) Breb.,                      124
+    _cardinalis_ Kitton,                         126
+    _circumsuta_ Bail.,                          118
+    cruciata A. S.,                              127
+    crumena Breb.,                               126
+    _davidsonii_ A. S.,                          126
+    delicatissima Lewis,                         128
+    _diaphana_ Bleisch,                          125
+    elegans Ehr.,                                125
+    fastuosa Ehr.,                               127
+    febigerii Lewis,                             128
+    gemma Ehr.,                                  125
+    gracilis Grun.,                              127
+    guatimalensis Ehr.,                          126
+    intermedia Lewis,                            128
+    linearis Wm. Sm.,                            124
+    _moelleriana_ Grun.,                         124
+    oblonga Ehr.?,                               127
+    ovalis Breb.,                                126
+      var. _pinnata_ (Wm. Sm.) De Toni,          126
+    panduriformis Wm. Sm.,                       126
+    pinnata Wm. Sm.,                             126
+      var. minuta Grun.,                         126
+    recedens A. S.,                              127
+    robusta Ehr.,                                124
+    splendida (Ehr.) Kuetz.,                     125
+    striatula Turpin,                            125
+    tenera Greg.,                                125
+
+  Synedra,                                        47
+    acus Kuetz.,                                  48
+    affinis Kuetz.,                               50
+      var. parva (Kuetz.) V. H.,                  50
+      var. tabulata (Ag.) V. H.,                  50
+    biceps (Kuetz.) A. S.,                        48
+    capitata Ehr.,                                48
+    danica Kuetz.,                                48
+    fulgens (Grev.) Wm. Sm.,                      50
+    goulardi Breb.,                               48
+    _gracilis_ Kuetz.,                            50
+    oxyrhynchus var. undulata Grun.,              48
+    pulchella (Ralfs) Kuetz.,                     48
+      var. abnormis Macchiati?,                   48
+      var. flexella n. var.,                      49
+    radians Kuetz.,                               49
+    ulna (Nitzsch) Ehr.,                          47
+    vaucheriae var. parvula (Kuetz.) Rab.,        49
+
+  Tabellaria,                                     36
+    fenestrata (Lyng.),                           36
+    flocculosa (Roth) Kuetz.,                     36
+
+  Terpsinoe,                                      34
+    americana (Bail.) Ralfs,                      34
+    novae-caesareae Boyer,                        34
+
+  _Tessella_
+    _interrupta_ Ehr.,                            38
+
+  Trachyneis,                                     79
+    aspera var. intermedia Grun.,                 79
+
+  Trachysphenia,                                  47
+    australis Petit,                              47
+
+  _Triceratium_
+    _alternans_ Bail.,                            33
+    _favus_ Ehr.,                                 31
+    _obtusum_ Br.,                                33
+    _pileotus_ Ehr.,                              30
+    _punctatum_ Br.,                              33
+    _sculptum_ Shad.,                             33
+
+  Trinacria,                                      30
+    pileolus (Ehr.) Grun.,                        30
+
+  _Tripodiscus_
+    _argus_ Ehr.,                                 26
+
+  Tropidoneis,                                    68
+    lepidoptera (Greg.) Cl.,                      69
+
+  _Tryblionella_
+    _punctata_ Wm. Sm.,                          116
+    _scutellum_ Wm. Sm.,                         118
+
+  _Vibrio_
+    _paxillifer_ O. F. Mueller,                  119
+
+
+
+
+PLATES
+
+
+PLATE 1
+
+
+
+  MELOSEIRA
+
+  3-4            Meloseira roeseana var. epidendron (Ehr.) Grun.         15
+
+  5-6            Meloseira roeseana Rab.                                 15
+
+  8-9            Meloseira distans (Ehr.) Kuetz.                         14
+
+  10             Meloseira granulata (Ehr.) Ralfs                        15
+
+  11-12          Meloseira sulcata Kuetz.                                15
+
+  15-16-17       Meloseira undulata (Ehr.) Kuetz.                        15
+
+  GAILLONELLA
+
+  13-14          Gaillonella nummuloides (Dillw.) Bory                   16
+
+  LYSIGONIUM
+
+  7              Lysigonium moniliforme (Muell.) Link.                   16
+
+  18-19          Lysigonium varians (Ag.) De Toni                        17
+
+  HYALODISCUS
+
+  20             Hyalodiscus scoticus (Kuetz.) Grun.                     18
+
+  21             Hyalodiscus radiatus var. arctica Grun.                 17
+
+  22             Hyalodiscus stelliger Bail.                             17
+
+  NOTE.--The figures in all of the plates, except when otherwise
+  noted, are magnified 800 diameters.
+
+
+
+[Illustration: PLATE 1]
+
+
+PLATE 2
+
+
+
+  STEPHANOPYXIS
+
+  1-2            Stephanopyxis turris (Grev.) Ralfs                      18
+
+  3              Stephanopyxis corona (Ehr.) Grun.                       18
+
+  CYCLOTELLA
+
+  4              Cyclotella meneghiniana var. stelligera Cl. and Grun.   20
+
+  5-6            Cyclotella operculata (Ag.) Kuetz.                      20
+
+  7              Cyclotella comta (Ehr.) Kuetz.                          20
+
+  8              Cyclotella meneghiniana Kuetz.                          19
+
+  9              Cyclotella striata (Kuetz.) Grun.                       19
+
+  10             Cyclotella stylorum (Br.?) V. H.                        20
+
+  11             Cyclotella antiqua Wm. Sm.                              20
+
+  12             Cyclotella meneghiniana var. stellulifera Cl. and Grun. 20
+
+  COSCINODISCUS
+
+  13             Coscinodiscus denarius A. S.                            22
+
+  14             Coscinodiscus excentricus Ehr.                          21
+
+  15-17          Coscinodiscus subtilis Ehr.                             21
+
+  16             Coscinodiscus asteromphalus Ehr.                        23
+
+  18             Coscinodiscus nitidus Greg.                             21
+
+  19             Coscinodiscus nitidulus Grun.                           21
+
+  20             Coscinodiscus excentricus var. perpusilla Grun. ?       21
+
+
+
+[Illustration: PLATE 2]
+
+
+PLATE 3
+
+
+
+  COSCINODISCUS--Continued
+
+  1-11           Coscinodiscus radiatus Ehr.                             23
+
+  2              Coscinodiscus velatus Ehr.                              22
+
+  3              Coscinodiscus biangulatus A. S.                         23
+
+  4              Coscinodiscus subaulacodiscoidalis Rattr.               23
+
+  5              Coscinodiscus lewisianus Grev.                          24
+
+  7              Coscinodiscus argus Ehr.                                23
+
+  8              Coscinodiscus lineatus Ehr.                             21
+
+  9              Coscinodiscus marginatus Ehr.                           22
+
+  10             Coscinodiscus oculus-iridis Ehr.                        23
+
+  ACTINOCYCLUS
+
+  6              Actinocyclus ellipticus var. delawarensis n. var.       27
+
+
+
+[Illustration: PLATE 3]
+
+
+PLATE 4
+
+
+
+  ACTINOPTYCHUS
+
+  1-4-6          Actinoptychus undulatus (Kuetz.) Ralfs.                 24
+
+  2              Actinoptychus undulatus (inner stratum)                 24
+
+  3              Actinoptychus heliopelta Grun. var.?                    25
+
+  5              Actinoptychus vulgaris var. interrupta n. var.          24
+
+  POLYMYXUS
+
+  7              Polymyxus coronalis L. W. Bail.                         25
+
+  AULACODISCUS
+
+  8              Aulacodiscus argus (Ehr.) A. S.                         26
+
+
+
+[Illustration: PLATE 4]
+
+
+PLATE 5
+
+
+
+  EUODIA
+
+  1              Euodia gibba Bail.                                      34
+
+  POLYMYXUS
+
+  2              Polymyxus coronalis L. W. Bail., zone view              25
+
+  EUPODISCUS
+
+  3              Eupodiscus radiatus Bail.                               28
+
+  AULISCUS
+
+  4              Auliscus caelatus Bail.                                 29
+
+  5              Auliscus sculptus (Wm. Sm.) Ralfs                       29
+
+  6              Auliscus punctatus Bail.                                28
+
+  7              Auliscus (intermediate form between A. caelatus and A.
+      sculptus)                                                          29
+
+  8              Auliscus pruinosus Bail.                                28
+
+  PSEUDAULISCUS
+
+  9              Pseudauliscus radiatus (Bail.) Rattr.                   29
+
+  10             Pseudauliscus spinosus (Christian) Rattr.               29
+
+
+
+[Illustration: PLATE 5]
+
+
+PLATE 6
+
+
+
+  ACTINOCYCLUS
+
+  1              Actinocyclus barkleyi var. aggregata Rattr.             27
+
+  2              Actinocyclus moniliformis Ralfs.                        27
+
+  BIDDULPHIA
+
+  3              Biddulphia antediluviana (Ehr.) V. H.                   32
+
+  5              Biddulphia reticulum (Ehr.)                             33
+
+  6              Biddulphia favus (Ehr.) V. H.                           31
+
+  7-8            Biddulphia alternans (Bail.) V. H.                      33
+
+  TRINACRIA
+
+  9              Trinacria pileolus (Ehr.) Grun.                         30
+
+  DITYLUM
+
+  4              Ditylum intricatum (West) Grun.                         30
+
+  TERPSINOE
+
+  10             Terpsinoe americana (Bail.) Ralfs.                      34
+
+  11             Terpsinoe novae-caesareae Boyer                         34
+
+
+
+[Illustration: PLATE 6]
+
+
+PLATE 7
+
+
+
+  BIDDULPHIA
+
+  1-2-3-4        Biddulphia biddulphiana (Smith)                         31
+
+  5              Biddulphia rhombus (Ehr.) Wm. Sm.                       32
+
+  6              Biddulphia granulata Roper                              32
+
+  7              Biddulphia turgida (Ehr.) Wm. Sm.                       32
+
+  8              Biddulphia smithii (Ralfs) V. H.                        32
+
+  9              Biddulphia laevis Ehr.                                  33
+
+  10             Biddulphia laevis Ehr. Sporangial frustules (260 diam.) 33
+
+  EUNOTOGRAMMA
+
+  11             Eunotogramma laeve Grun.                                33
+
+
+
+[Illustration: PLATE 7]
+
+
+PLATE 8
+
+
+
+  RHABDONEMA
+
+  1-2-3          Rhabdonema arcuatum (Lyng.) Kuetz.                      35
+
+  4-5-6          Rhabdonema adriaticum Kuetz.                            36
+
+  7              Rhabdonema minutum Kuetz.                               36
+
+  TABELLARIA
+
+  8-9-10         Tabellaria flocculosa (Roth) Kuetz.                     36
+
+  11-12          Tabellaria fenestrata (Lyng.) Kuetz.                    36
+
+  GRAMMATOPHORA
+
+  13-14          Grammatophora marina var. subtilissima (Bail.) V. H.    37
+
+  15-16          Grammatophora angulosa var. hamulifera (Kuetz.) Grun.   37
+
+  17-18          Grammatophora marina (Lyng.) Kuetz.                     37
+
+  19-20          Grammatophora islandica Ehr.                            37
+
+  21             Grammatophora serpentina Ralfs.                         37
+
+  STRIATELLA
+
+  22-23          Striatella unipunctata (Lyng.) Ag.                      38
+
+  24             Striatella interrupta (Ehr.) Heib.                      38
+
+  ATTHEYA
+
+  25             Attheya decora West                                     38
+
+
+
+[Illustration: PLATE 8]
+
+
+PLATE 9
+
+
+
+  LICMOPHORA
+
+  1-2            Licmophora flabellata (Carm.) Ag.                       39
+
+  3-4            Licmophora lyngbyei Kuetz.                              40
+
+  5              Licmophora ehrenbergii (Kuetz.) Grun.                   40
+
+  6-7            Licmophora paradoxa (Lyng.) Ag.                         39
+
+  8-9            Licmophora ovulum Mer.                                  39
+
+  10             Licmophora baileyi (Edw.) Grun.                         40
+
+  11             Licmophora gracilis (Ehr.) Grun.                        39
+
+  12-13          Licmophora gracilis var. elongata (Kuetz.) De Toni      39
+
+  14-15          Licmophora tincta (Ag.) Grun.                           40
+
+
+
+[Illustration: PLATE 9]
+
+
+PLATE 10
+
+
+
+  MERIDION
+
+  1-2-3          Meridion circulare (Grev.) Ag.                          40
+
+  DIATOMA
+
+  4              Diatoma vulgare var. grande (Wm. Sm.) Grun.             42
+
+  5-6            Diatoma anceps (Ehr.) Kirchn.                           42
+
+  7-8            Diatoma hiemale (Lyng.) Heib.                           42
+
+  9-10           Diatoma vulgare Bory.                                   42
+
+  PLAGIOGRAMMA
+
+  11             Plagiogramma tessellatum Grev.                          43
+
+  12             Plagiogramma obesum Grev.                               43
+
+  13             Plagiogramma pygmaeum Grev.                             43
+
+  14             Plagiogramma wallichianum Grev.                         43
+
+  EUNOTOGRAMMA
+
+  15             Eunotogramma laeve Grun.                                33
+
+  OPEPHORA
+
+  16-19          Opephora schwartzii (Grun.) Petit.                      43
+
+  17             Opephora pinnata var. lanceolata n. var.                44
+
+  18             Opephora pacifica (Grun.) Petit.                        43
+
+  FRAGILARIA
+
+  20-21          Fragilaria virescens Ralfs.                             44
+
+  22-23          Fragilaria arctica Grun.                                44
+
+  24-25-27-28-29 Fragilaria undata Wm. Sm.                               44
+
+  26             Fragilaria undata Wm. Sm., var.?                        44
+
+  30             Fragilaria construens (Ehr.) Grun.                      45
+
+  31             Fragilaria harrisonii (Wm. Sm.) Grun.                   45
+
+  34             Fragilaria capucina var. mesolepta Rab.                 45
+
+  35             Fragilaria parasitica (Wm. Sm.)                         45
+
+  36             Fragilaria sp. ?                                        45
+
+  37             Fragilaria linearis Cstr.                               45
+
+  RHAPHONEIS
+
+  38             Rhaphoneis amphiceros Ehr.                              46
+
+  39-40          Rhaphoneis amphiceros var. rhombica Grun.               46
+
+  41             Rhaphoneis belgica var. intermedia Grun.                46
+
+  SYNEDRA
+
+  32-33          Synedra radians Kuetz.                                  49
+
+
+
+[Illustration: PLATE 10]
+
+
+PLATE 11
+
+
+
+  SYNEDRA--Continued
+
+  1-5-6          Synedra ulna (Nitzsch) Ehr. Sporangial                  47
+
+  2              Synedra danica Kuetz.                                   48
+
+  3              Synedra biceps (Kuetz.) A. S.                           48
+
+  4-7-11         Synedra ulna (Nitzsch) Ehr.                             47
+
+  8              Synedra capitata Ehr.                                   48
+
+  9-18           Synedra acus Kuetz.                                     48
+
+  10             Synedra fulgens (Grev.) Wm. Sm.                         50
+
+  12-13          Synedra goulardi Breb.                                  48
+
+  14-15-16       Synedra pulchella (Ralfs) Kuetz.                        48
+
+  17             Synedra pulchella var. abnormis Macchiati?              48
+
+
+
+[Illustration: PLATE 11]
+
+
+PLATE 12
+
+
+
+  SYNEDRA--Continued
+
+  1              Synedra oxyrhynchus var. undulata Grun.                 48
+
+  2              Synedra pulchella var. flexella n. var.                 49
+
+  3              Synedra affinis Kuetz.                                  50
+
+  4              Synedra affinis var. tabulata (Ag.) V. H.               50
+
+  5-6            Synedra vaucheriae var. parvula (Kuetz.) Rab.           49
+
+  7              Synedra affinis var. parva (Kuetz.) V. H.               50
+
+  8              Synedra radians (Kuetz.) H. L. S.                       49
+
+  DIMEROGRAMMA
+
+  9-10           Dimerogramma marinum (Greg.)                            46
+
+  11             Dimerogramma surirella (Ehr.) Grun.                     46
+
+  12-13-14       Dimerogramma minus (Greg.) Ralfs.                       47
+
+  TRACHYSPHENIA
+
+  15             Trachysphenia australis Petit.                          47
+
+  ACTINELLA
+
+  16-17-18       Actinella punctata Lewis.                               54
+
+  ASTERIONELLA
+
+  19-20-21       Asterionella formosa Hass.                              50
+
+  22             Asterionella inflata Heib.                              50
+
+  EUNOTIA
+
+  23             Eunotia hemicyclus (Ehr.) Ralfs                         53
+
+  24-25          Eunotia lunaris (Ehr.) Grun.                            53
+
+
+
+[Illustration: PLATE 12]
+
+
+PLATE 13
+
+
+
+  EUNOTIA--Continued
+
+  1-2            Eunotia major (Wm. Sm.) Rab.                            51
+
+  3              Eunotia gracilis (Ehr.) Rab.                            51
+
+  4              Eunotia major (Wm. Sm.) Rab. (intermediate form)        51
+
+  5              Eunotia praerupta Ehr.                                  53
+
+  6-7            Eunotia pectinalis (Kuetz.)                             52
+
+  8-10           Eunotia pectinalis var. undulata Ralfs                  52
+
+  9              Eunotia pectinalis var. solierolii (Kuetz.)             52
+
+  11             Eunotia luna Ehr. var.?                                 52
+
+  12             Eunotia pectinalis var. ventricosa Grun.                52
+
+  13             Eunotia robusta Ralfs (E. scalaris Ehr.)                53
+
+  14             Eunotia robusta Ralfs (E. prioritis Ehr.)               53
+
+  15             Eunotia robusta Ralfs (E. decadon Ehr.)                 53
+
+  16             Eunotia robusta Ralfs (E. octodon Ehr.)                 53
+
+  17-22          Eunotia robusta Ralfs (E. heptodon Ehr.)                53
+
+  18             Eunotia bactriana Ehr.                                  54
+
+  19             Eunotia praerupta var. bidens Grun.                     53
+
+  20             Eunotia bidentula Wm. Sm.                               54
+
+  21             Eunotia robusta Ralfs (E. diadema Ehr.)                 53
+
+  23             Eunotia praerupta Ehr. var.?                            53
+
+  24             Eunotia robusta Ralfs (E. triodon Ehr.)                 53
+
+  25             Eunotia robusta Ralfs (E. tetraodon Ehr.)               53
+
+  26             Eunotia formica Ehr. var.?                              54
+
+  27             Eunotia biceps Ehr.                                     53
+
+  28-29          Eunotia sp.?                                            54
+
+  30-31          Eunotia veneris Kuetz.                                  52
+
+  32             Eunotia nymanniana Grun.                                51
+
+
+
+[Illustration: PLATE 13]
+
+
+PLATE 14
+
+
+
+  AMPHIPRORA
+
+  1-2            Amphiprora pulchra Bail.                                68
+
+  3              Amphiprora alata Kuetz.                                 68
+
+  4              Amphiprora conspicua Grev.                              68
+
+  5              Amphiprora paludosa Wm. Sm.                             68
+
+  6-7            Amphiprora ornata Bail.                                 68
+
+  TROPIDONEIS
+
+  8-9            Tropidoneis lepidoptera (Greg.) Cleve.                  69
+
+  SCOLIOTROPIS
+
+  10-11          Scoliotropis latestriata var. amphora Cleve.            69
+
+
+
+[Illustration: PLATE 14]
+
+
+PLATE 15
+
+
+
+  AMPHORA
+
+  1              Amphora robusta Greg.                                   65
+
+  3              Amphora crassa Greg.                                    65
+
+  4              Amphora obtusa Greg.                                    67
+
+  5-6-19         Amphora proteus Greg.                                   65
+
+  7              Amphora ovalis (Breb.) Kuetz.                           65
+
+  8-18           Amphora coffaeiformis (Ag.) Kuetz.                      66
+
+  9-10           Amphora lineolata Ehr.                                  66
+
+  11             Amphora areolata Grun.                                  66
+
+  12-21          Amphora ostrearia Breb.                                 66
+
+  13             Amphora laevis Greg.                                    66
+
+  14-15          Amphora ocellata var. cingulata Cleve.                  67
+
+  16             Amphora angusta var. culensteinii Grun.                 67
+
+  17             Amphora arenaria Donk.                                  67
+
+  20             Amphora acuta Greg.                                     66
+
+  AURICULA
+
+  2              Auricula mucronata (H. L. Smith) Peragallo              69
+
+
+
+[Illustration: PLATE 15]
+
+
+PLATE 16
+
+
+
+  ACHNANTHES
+
+  1-2            Achnanthes longipes Ag.                                 58
+
+  3              Achnanthes brevipes Ag.                                 59
+
+  4-5-6          Achnanthes subsessilis Kuetz.                           59
+
+  7-8            Achnanthes inflata (Kuetz.) Grun.                       59
+
+  9              Achnanthes coarctata (Breb.) Grun.                      59
+
+  10-11-12       Achnanthes lanceolata (Breb.) Grun.                     59
+
+  13             Achnanthes danica (Floegel) Grun. (lower valve)         60
+
+  14-15          Achnanthes exigua Grun.                                 59
+
+  16-17          Achnanthes linearis forma curta H. L. Smith             59
+
+  COCCONEIS
+
+  18             Cocconeis scutellum var.?                               57
+
+  19-20          Cocconeis placentula Ehr.                               57
+
+  21             Cocconeis scutellum Ehr. (upper valve)                  57
+
+  22             Cocconeis dirupta Greg. (lower valve)                   58
+
+  23-24          Cocconeis pediculus Ehr.                                57
+
+  25-26          Cocconeis pellucida Grun.                               58
+
+  27-28          Cocconeis scutellum var. ornata Grun.                   57
+
+  29             Cocconeis placentula var. lineata (Ehr.) V. H.          58
+
+  ANORTHONEIS
+
+  30-31          Anorthoneis excentrica (Donk.) Grun.                    56
+
+
+
+[Illustration: PLATE 16]
+
+
+PLATE 17
+
+
+
+  FRUSTULIA
+
+  1              Frustulia lewisiana (Grev.) De Toni                     77
+
+  2              Frustulia rhomboides (Ehr.) De Toni                     77
+
+  3              Frustulia rhomboides var. amphipleuroides Grun.         77
+
+  4              Frustulia vulgaris (Thwaites) De Toni                   77
+
+  5              Frustulia interposita (Lewis) De Toni                   78
+
+  6              Frustulia rhomboides var. saxonica (Rab.) De Toni       77
+
+  BREBISSONIA
+
+  7              Brebissonia boeckii (Kuetz.) Grun.                      79
+
+  8              Brebissonia palmerii n. sp.                             80
+
+  AMPHIPLEURA
+
+  9              Amphipleura pellucida Kuetz.                            78
+
+  10-11          Amphipleura rutilans (Trentepohl) Cl.                   78
+
+  ANOMOEONEIS
+
+  12             Anomoeoneis serians (Breb.) Cl.                         80
+
+  13             Anomoeoneis serians forma minor                         80
+
+  14             Anomoeoneis follis (Ehr.) Cl.                           80
+
+  TRACHYNEIS
+
+  15             Trachyneis aspera var. intermedia Grun.                 70
+
+  MASTOGLOIA
+
+  16             Mastogloia kinsmanii Lewis                              87
+
+  17             Mastogloia angulata Lewis                               87
+
+  18             Mastogloia lanceolata Thwaites                          87
+
+  19             Mastogloia smithii Thwaites                             87
+
+  20             Mastogloia elegans Lewis                                87
+
+  21-22-23       Mastogloia apiculata Wm. Sm.                            87
+
+  24             Mastogloia exigua Lewis                                 87
+
+
+
+[Illustration: PLATE 17]
+
+
+PLATE 18
+
+
+
+  CYMBELLA
+
+  1              Cymbella aspera (Ehr.) Cl.                              61
+
+  2              Cymbella cymbiformis (Kuetz.) Breb.                     62
+
+  3              Cymbella cistula (Hempr.) Kirchn.                       62
+
+  4              Cymbella lanceolata (Ehr.) Kirchn.                      62
+
+  5              Cymbella mexicana (Ehr.) A. S.                          62
+
+  6              Cymbella naviculiformis Auerswald.                      60
+
+  7              Cymbella tumida (Breb.) V. H.                           62
+
+  8              Cymbella philadelphica n. sp.                           63
+
+  9              Cymbella ehrenbergii Kuetz.                             60
+
+  10             Cymbella heteropleura (Ehr.) Kuetz.                     60
+
+  11             Cymbella rhomboidea n. sp.                              63
+
+  12             Cymbella turgida (Greg.) Cl. var.?                      63
+
+  13             Cymbella sinuata Greg.                                  61
+
+  14             Cymbella ventricosa Kuetz.                              62
+
+  15-19          Cymbella excisa (Kuetz.) De Toni.                       61
+
+  16             Cymbella amphicephala Naegeli.                          61
+
+  17             Cymbella cuspidata Kuetz.                               60
+
+  18             Cymbella affinis Kuetz.                                 61
+
+  20             Cymbella gracilis (Rab.) Cl.                            64
+
+  21             Cymbella prostrata (Berk.) Cl.                          63
+
+  22             Cymbella ventricosa Kuetz.?                             62
+
+  23             Cymbella turgida (Greg.) Cl.                            63
+
+  24             Cymbella triangulum (Ehr.) Cl.                          63
+
+  25             Cymbella lacustris (Ag.) Cl.                            64
+
+
+
+[Illustration: PLATE 18]
+
+
+PLATE 19
+
+
+
+  GOMPHONEIS
+
+  1              Gomphoneis mamilla (Ehr.) Cl.                           70
+
+  2              Gomphoneis herculaneum (Ehr.) Cl.                       70
+
+  GOMPHONEMA
+
+  3              Gomphonema montanum Schum.                              71
+
+  4              Gomphonema geminatum Lyng.                              71
+
+  5              Gomphonema acuminatum var. turris (Ehr.) Cl.            71
+
+  6-12           Gomphonema lanceolatum var. insignis (Greg.) Cl.        71
+
+  7              Gomphonema acuminatum var. coronata (Ehr.) Cl.          71
+
+  8              Gomphonema constrictum Ehr.                             72
+
+  9-10           Gomphonema sphaerophorum Ehr.                           72
+
+  11             Gomphonema acuminatum var. turris (Ehr.) Cl.?           71
+
+  13             Gomphonema ventricosum Greg.                            73
+
+  14             Gomphonema intricatum Kuetz.                            72
+
+  15             Gomphonema aequale Greg.                                72
+
+  16             Gomphonema sarcophagus Greg.                            72
+
+  17             Gomphonema parvulum var. micropus (Kuetz.) Cl.          73
+
+  18-19          Gomphonema angustatum Kuetz.                            72
+
+  20             Gomphonema acuminatum var. trigonocephala (Ehr.) Cl.    71
+
+  21             Gomphonema augur Ehr.                                   72
+
+  22             Gomphonema capitatum Ehr.                               72
+
+  23             Gomphonema olivaceum Lyng.                              73
+
+  24             Gomphonema brasiliense var. demerarae Grun.?            73
+
+  RHOICOSPHENIA
+
+  25-26-27       Rhoicosphenia curvata (Kuetz.) Grun.                    56
+
+
+
+[Illustration: PLATE 19]
+
+
+PLATE 20
+
+
+
+  DICTYONEIS
+
+  1              Dictyoneis marginata var. maxima n. var.                79
+
+  2              Dictyoneis marginata var. commutata Cleve.              79
+
+  3              Dictyoneis marginata var. typica Cleve.                 78
+
+  DIPLONEIS
+
+  4              Diploneis crabro var. pandura (Breb.) Cl.               85
+
+  6              Diploneis campylodiscus (Grun.) Cl.                     86
+
+  7-8            Diploneis gruendleri (A. S.) Cl.                        85
+
+  9              Diploneis crabro Ehr. var.?                             85
+
+  10             Diploneis excentrica n. sp.                             85
+
+  11             Diploneis fusca var. delicata (A. S.) Cl.               85
+
+  12             Diploneis puella (Schum.) Cl.                           85
+
+  13             Diploneis crabro var. pandurella Cl.?                   85
+
+  14             Diploneis elliptica (Kuetz.) Cl.                        84
+
+  15             Diploneis crabro var. expleta (A. S.) Cl.               85
+
+  16             Diploneis geminata (Grev.) Cl.                          86
+
+  17             Diploneis smithii (Breb.) Cl.                           84
+
+  NAVICULA
+
+  5              Navicula lyra Ehr. var.?                                93
+
+
+
+[Illustration: PLATE 20]
+
+
+PLATE 21
+
+
+
+  CALONEIS
+
+  1              Caloneis permagna (Bail.) Cl.                           82
+
+  2              Caloneis permagna var. lewisiana n. var.                82
+
+  3              Caloneis silicula (Ehr.) Cl.                            81
+
+  4              Caloneis silicula var. inflata (Grun.) Cl.              81
+
+  5              Caloneis brevis var. vexans (Grun.) Cl.                 82
+
+  6-7            Caloneis wardii Cl.                                     82
+
+  8              Caloneis trinodis (Lewis)                               81
+
+  9              Caloneis trinodis (Lewis) var.?                         81
+
+  10             Caloneis powellii (Lewis) Cl.                           83
+
+  18             Caloneis formosa (Greg.) Cl.                            82
+
+  NEIDIUM
+
+  11             Neidium affine (Ehr.) Pfitzer                           83
+
+  12             Neidium affine var. genuina forma minor Cl.             83
+
+  13             Neidium affine var. amphirhyncus (Ehr.) Cl.             83
+
+  14             Neidium amphigomphus (Ehr.) Pfitzer.                    83
+
+  15             Neidium hitchcockii (Ehr.) Cl.                          84
+
+  16             Neidium productum (Wm. Sm.) Cl.                         83
+
+  17             Neidium iridus (Ehr.) Cl.                               84
+
+
+
+[Illustration: PLATE 21]
+
+
+PLATE 22
+
+
+
+  PLEUROSIGMA
+
+  1              Pleurosigma strigosum Wm. Sm.                           74
+
+  2              Pleurosigma rigidum Wm. Sm.                             75
+
+  3              Pleurosigma angulatum (Quekett) Cl.                     74
+
+  4              Pleurosigma obscurum Wm. Sm.                            74
+
+  5              Pleurosigma formosum Wm. Sm.                            73
+
+  6              Pleurosigma naviculaceum Breb.                          74
+
+  7              Pleurosigma aestuarii Breb.                             74
+
+  8              Pleurosigma virginiacum H. L. Smith                     74
+
+
+
+[Illustration: PLATE 22]
+
+
+PLATE 23
+
+
+
+  GYROSIGMA
+
+  1              Gyrosigma strigilis (Wm. Sm.) Cl.                       76
+
+  2              Gyrosigma balticum (Ehr.) Cl.                           75
+
+  3              Gyrosigma hippocampus (Ehr.)                            75
+
+  4              Gyrosigma simile (Grun.)                                76
+
+  5              Gyrosigma acuminatum (Kuetz.) Cl.                       76
+
+  6              Gyrosigma scalproides (Rab.) Cl.                        76
+
+  7              Gyrosigma parkeri var. stauroneioides Grun.             75
+
+  8              Gyrosigma spencerii var. nodifera Grun.                 76
+
+  9              Gyrosigma fasciola (Ehr.) Cl.                           77
+
+
+
+[Illustration: PLATE 23]
+
+
+PLATE 24
+
+
+
+  NAVICULA
+
+  1              Navicula maculata (Bail.) Cl.                           90
+
+  2              Navicula praetexta Ehr.                                 92
+
+  3              Navicula latissima Greg.                                90
+
+  4              Navicula irrorata Grev.                                 93
+
+  5              Navicula latissima var. elongata (Pant.) Cl.            91
+
+  6              Navicula fuchsii Pant.                                  91
+
+
+
+[Illustration: PLATE 24]
+
+
+PLATE 25
+
+
+
+  NAVICULA
+
+  1              Navicula tumida (Breb.) Cl.                             99
+
+  2              Navicula brasiliensis var. bicuneata Cl. forma
+      constricta.                                                        92
+
+  3              Navicula delawarensis Grun.                             92
+
+  4-6            Navicula pusilla Wm. Sm.                                91
+
+  5              Navicula humerosa Breb.                                 91
+
+  7              Navicula spectabilis var. emarginata Cl.                94
+
+  8              Navicula pusilla var. subcapitata n. var.               91
+
+  9              Navicula punctulata Wm. Sm.                             92
+
+  10             Navicula lyra Ehr.                                      93
+
+  11             Navicula hennedyi var. manca A. S.                      93
+
+  12             Navicula hennedyi Wm. Sm.                               93
+
+  13             Navicula lyra var. dilatata A. S.                       93
+
+  14             Navicula yarrensis Grun.                               101
+
+  15             Navicula yarrensis Grun. (smaller form)                101
+
+  16             Navicula yarrensis Grun. var.?                         101
+
+
+
+[Illustration: PLATE 25]
+
+
+PLATE 26
+
+
+
+  NAVICULA
+
+  1-2            Navicula cuspidata Kuetz.                              100
+
+  3              Navicula cuspidata var. ambigua (Ehr.) Cl.             100
+
+  4              Navicula spicula (Hickie) Cl.                          100
+
+  5              Navicula integra Wm. Sm.                                99
+
+  6              Navicula mutica Kuetz.                                  97
+
+  8              Navicula americana Ehr.                                 98
+
+  9              Navicula pupula var. bacillarioides Grun.               98
+
+  10             Navicula bacillum Ehr.                                  98
+
+  11             Navicula semen Ehr.                                     98
+
+  12             Navicula atomus Naegeli.                               100
+
+  13             Navicula minima Grun.                                   98
+
+  14             Navicula ramosissima (Ag.) Cl.                          95
+
+  15             Navicula crucigera (Wm. Sm.) Cl.                       100
+
+  16             Navicula viridula var. rostellata Kuetz.                95
+
+  17             Navicula radiosa Kuetz.                                 94
+
+  19             Navicula gracilis var. schizonemoides (Ehr.) V. H.      95
+
+  20             Navicula peregrina Ehr.                                 94
+
+  21             Navicula cyprinus (Wm. Sm.)                             95
+
+  22             Navicula reinhardtii Grun.                              95
+
+  23             Navicula lanceolata var. arenaria (Donk.) Cl.           95
+
+  24             Navicula salinarum Grun.                                95
+
+  25             Navicula gastrum Ehr.                                   96
+
+  26             Navicula anglica Ralfs.                                 96
+
+  DIPLONEIS
+
+  7              Diploneis oculata (Breb.) Cl.                           86
+
+  STAURONEIS
+
+  18             Stauroneis frickei var. angusta n. var.                 88
+
+
+
+[Illustration: PLATE 26]
+
+
+PLATE 27
+
+
+
+  STAURONEIS--Continued
+
+  1              Stauroneis phoenicenteron Ehr.                          88
+
+  2              Stauroneis acuta Wm. Sm.                                89
+
+  3              Stauroneis americana A. S.                              89
+
+  4              Stauroneis anceps var.?                                 88
+
+  5              Stauroneis anceps var. gracilis (Ehr.) Cl.              88
+
+  6              Stauroneis salina Wm. Sm.                               89
+
+  7              Stauroneis anceps var. amphicephala (Kuetz.) Cl.        88
+
+  8              Stauroneis anceps var.?                                 88
+
+  9              Stauroneis anceps var.?                                 88
+
+  10             Stauroneis crucicula (Grun.) Cl.                        89
+
+  11             Stauroneis smithii Grun.                                89
+
+  NAVICULA
+
+  12             Navicula lacustris Greg.                                92
+
+  13             Navicula hasta Pant.                                    97
+
+  14             Navicula hasta var. punctata n. var.                    97
+
+  15             Navicula punctata var. asymmetrica Lagerstedt           92
+
+  16             Navicula dicephala Wm. Sm.                              96
+
+  17             Navicula placenta Ehr.                                  94
+
+  18-19          Navicula inflexa Greg.                                  96
+
+  20             Navicula pinnata Pant.?                                 96
+
+  21             Navicula oblonga Kuetz.                                 97
+
+  22             Navicula pennata A. S.                                  96
+
+  23             Navicula pygmaea Kuetz.                                 94
+
+  24             Navicula humilis Donk.                                  96
+
+
+
+[Illustration: PLATE 27]
+
+
+PLATE 28
+
+
+
+  PINNULARIA
+
+  1              Pinnularia nobilis Ehr.                                103
+
+  2              Pinnularia major var. pulchella n. var.                102
+
+  3              Pinnularia dactylus Ehr.                               103
+
+  4              Pinnularia major (Kuetz.) Wm. Sm.                      102
+
+
+
+[Illustration: PLATE 28]
+
+
+PLATE 29
+
+
+
+  PINNULARIA--Continued
+
+  1              Pinnularia gentilis (Donk.) Cl.                        103
+
+  2              Pinnularia viridis Nitzsch.                            104
+
+  3              Pinnularia dactylus var. dariana (A. S.) Cl.           103
+
+  4              Pinnularia viridis var. fallax Cl.                     104
+
+  5              Pinnularia socialis Palmer                             104
+
+  6              Pinnularia aestuarii Cl.                               105
+
+  7              Pinnularia rectangulata (Greg.) Cl.                    110
+
+  8              Pinnularia trigonocephala Cl.                          103
+
+  9              Pinnularia major (Kuetz.) Wm. Sm. (small form near P.
+      viridis)                                                          102
+
+  10             Pinnularia dactylus var. demerarae Cl.                 103
+
+  11             Pinnularia mormonorum (Grun.)                          107
+
+  12             Pinnularia brebissonii (Kuetz.) Cl.                    107
+
+  13             Pinnularia mesolepta Ehr.                              105
+
+  14             Pinnularia termes var. stauroneiformis V. H.           106
+
+  15             Pinnularia molaris (Grun.) Cl.                         105
+
+  16             Pinnularia braunii Grun.                               106
+
+  17             Pinnularia termes (Ehr.) A. S.                         106
+
+  18             Pinnularia appendiculata (Ag.) Cl.                     106
+
+  19             Pinnularia microstauron (Ehr.) Cl. var.?               106
+
+  20             Pinnularia subcapitata Greg.                           105
+
+
+
+[Illustration: PLATE 29]
+
+
+PLATE 30
+
+
+
+  PINNULARIA--Continued
+
+  1              Pinnularia cardinaliculus Cl.                          107
+
+  2              Pinnularia viridis var. fallax Cl.? (var. B., Wm.
+      Sm.?).                                                            104
+
+  3              Pinnularia legumen Ehr.                                107
+
+  4              Pinnularia legumen var.?                               107
+
+  5              Pinnularia gibba (Kuetz.) V. H.                        109
+
+  6              Pinnularia mesogongyla (Ehr.) Cl.                      109
+
+  7              Pinnularia acrosphaeria (Breb.) Cl.                    108
+
+  8              Pinnularia acrosphaeria var. turgidula Grun.           108
+
+  9              Pinnularia tabellaria (Ehr.) Cl. var.?                 110
+
+  10             Pinnularia leptosoma Grun.                             105
+
+  11             Pinnularia stauroptera var. interrupta Cl.             110
+
+  12             Pinnularia stomatophora (Grun.) Cl.                    109
+
+  13             Pinnularia stauroptera (Grun.) Cl.                     110
+
+  14             Pinnularia parva (Ehr.) Cl. var.?                      108
+
+  15-19          Pinnularia nodosa forma capitata Cl.                   108
+
+  16             Pinnularia subcapitata var. paucistriata Grun.         105
+
+  17             Pinnularia viridis Nitzsch var.                        104
+
+  18             Pinnularia viridis var. caudata n. var.                104
+
+  20             Pinnularia mesolepta var. stauroneiformis Grun.        105
+
+  21             Pinnularia polyonca (Breb.) Lewis.                     108
+
+  22             Pinnularia borealis Ehr.                               109
+
+  23             Pinnularia lata (Breb.) Wm. Sm.                        109
+
+  24             Pinnularia borealis var. scalaris (Ehr.) Cl.           109
+
+  25             Pinnularia blandita n. sp.                             108
+
+
+
+[Illustration: PLATE 30]
+
+
+PLATE 31
+
+
+
+  NAVICULA
+
+  1              Navicula elegans Wm. Sm.                               101
+
+  2              Navicula elegans var. cuspidata Cl.                    101
+
+  3-4            Navicula grevillei (Ag.) Cl.                            99
+
+  5              Navicula libellus Greg.                                 99
+
+  6-7            Navicula palpebralis Breb.                             101
+
+  8              Navicula rhyncocephala Kuetz.                           97
+
+  9              Navicula cryptocephala Kuetz.                           97
+
+  10             Navicula longa (Greg.) Ralfs.                           97
+
+  PINNULARIA
+
+  11             Pinnularia brebissonii (Kuetz.) Cl.                    107
+
+  12             Pinnularia borealis Ehr.                               109
+
+  13             Pinnularia divergens var. elliptica Grun.              107
+
+  EPITHEMIA
+
+  14             Epithemia turgida (Ehr.) Kuetz.                        111
+
+  15-21          Epithemia argus Kuetz.                                 111
+
+  16             Epithemia argus var.?                                  111
+
+  17             Epithemia muelleri A. S.                               111
+
+  18             Epithemia zebra var. proboscidea (Kuetz.) Grun.        112
+
+  19             Epithemia gibberula var. producta Grun.                112
+
+  20             Epithemia musculus Kuetz.                              112
+
+  22             Epithemia musculus var. constricta (Breb.) V. H.       112
+
+  RHOPALODIA
+
+  23             Rhopalodia gibba (Kuetz.) Mueller                      112
+
+  24             Rhopalodia ventricosa (Kuetz.) Mueller                 113
+
+
+
+[Illustration: PLATE 31]
+
+
+PLATE 32
+
+
+
+  NITZSCHIA
+
+  1              Nitzschia circumsuta (Bail.) Grun.                     118
+
+  2              Nitzschia plana Wm. Sm.                                117
+
+  3              Nitzschia granulata Grun.                              116
+
+  4              Nitzschia navicularis (Breb.) Grun.                    116
+
+  5              Nitzschia panduriformis var. minor Grun.               117
+
+  6              Nitzschia apiculata (Greg.) Grun.                      117
+
+  7              Nitzschia tabellaria Grun.                             119
+
+  8              Nitzschia tryblionella Hantzsch                        116
+
+  10-11          Nitzschia bilobata Wm. Sm.                             118
+
+  12             Nitzschia litoralis var. delawarensis Grun.            118
+
+  13             Nitzschia acuminata (Wm. Sm.) Grun.                    117
+
+  14-25          Nitzschia amphibia Grun.                               122
+
+  15             Nitzschia palea (Kuetz.) Wm. Sm.                       122
+
+  16             Nitzschia fluminensis Grun.                            120
+
+  17             Nitzschia obtusa var. scalpelliformis Grun.            121
+
+  18             Nitzschia linearis (Ag.) Wm. Sm.                       122
+
+  19             Nitzschia communis Rab.                                122
+
+  20             Nitzschia clausii Hantzsch.                            121
+
+  21             Nitzschia epithemioides Grun.                          118
+
+  24             Nitzschia vermicularis (Kuetz.) Wm. Sm.                120
+
+  HANTZSCHIA
+
+  9              Hantzschia amphioxys (Ehr.) Grun.                      113
+
+  22             Hantzschia marina (Donk.) Grun.                        114
+
+  23             Hantzschia virgata (Roper) Grun.                       114
+
+
+
+[Illustration: PLATE 32]
+
+
+PLATE 33
+
+
+
+  NITZSCHIA
+
+  1              Nitzschia longissima (Breb.) Ralfs                     123
+
+  2              Nitzschia intermedia Hantzsch                          122
+
+  3              Nitzschia spectabilis var. americana Grun.             122
+
+  4-5            Nitzschia sigmatella Greg.                             121
+
+  6              Nitzschia scalaris (Ehr.) Wm. Sm.                      119
+
+  7              Nitzschia macilenta Greg.                              120
+
+  8              Nitzschia insignis Greg.                               119
+
+  9              Nitzschia vermicularis (Kuetz.) Hantzsch               120
+
+  10             Nitzschia longissima forma parva V. H.                 123
+
+  11             Nitzschia reversa Wm. Sm.                              123
+
+  12             Nitzschia acicularis (Kuetz.) Wm. Sm.                  123
+
+  13-14          Nitzschia paxillifer (O. F. Mueller) Heib.             119
+
+  HOMOEOCLADIA
+
+  15             Homoeocladia filiformis Wm. Sm.                        123
+
+
+
+[Illustration: PLATE 33]
+
+
+PLATE 34
+
+
+
+  SURIRELLA
+
+  1              Surirella striatula Turpin                             125
+
+  2              Surirella anceps Lewis                                 128
+
+  3              Surirella intermedia Lewis                             128
+
+  4              Surirella arctissima A. S.                             128
+
+  5-6            Surirella delicatissima Lewis                          128
+
+  7              Surirella intermedia Lewis forma minor?                128
+
+  CYMATOPLEURA
+
+  8-9            Cymatopleura solea (Breb.) Wm. Sm.                     129
+
+
+
+[Illustration: PLATE 34]
+
+
+PLATE 35
+
+
+
+  SURIRELLA
+
+  1              Surirella fastuosa Ehr.                                127
+
+  2              Surirella biseriata (Ehr.) Breb.                       124
+
+  3              Surirella splendida (Ehr.) Kuetz.                      125
+
+  4              Surirella crumena Breb.                                126
+
+  5              Surirella ovalis Breb.                                 126
+
+  6              Surirella tenera Greg.                                 125
+
+  7              Surirella recedens A. S.                               127
+
+  8              Surirella linearis Wm. Sm.                             124
+
+  9              Surirella oblonga Ehr.?                                127
+
+  10             Surirella cruciata A. S.                               127
+
+  11             Surirella gracilis Grun.                               127
+
+  12-13          Surirella amphioxys Wm. Sm.                            124
+
+
+
+[Illustration: PLATE 35]
+
+
+PLATE 36
+
+
+
+  SURIRELLA--Continued
+
+  1              Surirella elegans Ehr.                                 125
+
+  2              Surirella robusta Ehr.                                 124
+
+  3              Surirella febigerii Lewis                              128
+
+  4              Surirella gemma Ehr.                                   125
+
+  5              Surirella guatimalensis Ehr.                           126
+
+  6              Surirella panduriformis Wm. Sm.                        126
+
+  7-9            Surirella pinnata Wm. Sm.                              126
+
+  8              Surirella angusta Kuetz.                               127
+
+
+
+[Illustration: PLATE 36]
+
+
+PLATE 37
+
+
+
+  CYMATOPLEURA
+
+  1              Cymatopleura elliptica (Breb.) Wm. Sm.                 129
+
+  2              Cymatopleura elliptica forma spiralis                  129
+
+  3-4            Cymatopleura marina Lewis                              129
+
+  CAMPYLODISCUS
+
+  5              Campylodiscus hibernicus Ehr.                          130
+
+  6              Campylodiscus echeneis Ehr.                            130
+
+
+
+[Illustration: PLATE 37]
+
+
+PLATE 38
+
+
+
+  1              Amphora gigantea var. fusca A. S.                       65
+
+  2              Meloseira crenulata (Ehr.) Kuetz.                       15
+
+  3-4            Licmophora baileyi (Edw.) Grun.                         40
+
+  5              Coscinodiscus polyacanthus Grun.                        22
+
+  6-7            Ditylum intricatum (West) Grun.                         30
+
+  8              Pyxidicula cruciata Ehr.                                19
+
+  9              Gyrosigma scalproides (Rab.) Cl.                        76
+
+  10             Coscinodiscus asteromphalus var. omphalantha (Ehr.)
+      Grun.                                                              23
+
+  11             Rhabdonema minutum Kuetz.                               36
+
+  12             Gyrosigma kuetzingii (Grun.) Cl.                        76
+
+  13             Gyrosigma prolongatum (Wm. Sm.) Cl.                     76
+
+  14             Cymbella parva (Wm. Sm.) Cl.                            61
+
+  15             Gomphoneis herculaneum (Ehr.) Cl. (zone view)           70
+
+  16             Cymbella ventricosa Kuetz.                              62
+
+  17-18          Eunotia sp. (abnormal?)                                 54
+
+
+
+[Illustration: PLATE 38]
+
+
+PLATE 39
+
+
+
+  1              Nitzschia spectabilis var. americana Grun. (zone view) 122
+
+  2              Nitzschia panduriformis Greg.                          117
+
+  3              Hantzschia amphioxys (Ehr.) Grun.                      113
+
+  4              Hantzschia amphioxys var. major Grun.                  114
+
+  5              Nitzschia dubia Wm. Sm.                                118
+
+  6              Nitzschia amphioxys Wm. Sm.                            114
+
+  7              Nitzschia compressa (Bail.)                            116
+
+  8              Nitzschia compressa var. minor H. L. Smith             116
+
+  9              Surirella intermedia Lewis (zone view)                 128
+
+  10             Surirella arctissima A. S. forma minor                 128
+
+  11             Surirella ovalis Breb.                                 126
+
+  12             Surirella biseriata (Ehr.) Breb.                       124
+
+  13             Nitzschia sigma (Kuetz.) Wm. Sm.                       121
+
+  14             Nitzschia obtusa var. flexella H. L. Smith             121
+
+  15             Stauroneis legumen Ehr.                                 89
+
+  16             Nitzschia obtusa Wm. Sm.                               121
+
+
+
+[Illustration: PLATE 39]
+
+
+PLATE 40
+
+
+
+  1              Caloneis liber (Wm. Sm.) Cl.                            81
+
+  2              Anomoeoneis sphaerophora (Kuetz.) Cl.                   80
+
+  3              Nitzschia spathulata Breb.                             120
+
+  4              Stauroneis ? abnormal                                   89
+
+  5              Navicula ? abnormal                                    101
+
+  6              Podocystis adriatica Kuetz.                            129
+
+  7              Nitzschia dissipata (Kuetz.) Grun.                     120
+
+  8              Cymbella ventricosa Kuetz. (zone view)                  62
+
+  9              Navicula radiosa Kuetz. (zone view)                     94
+
+  10             Detail of Rhabdonema arcuatum (Lyng.) Kuetz.            35
+
+  11             Diatoma anceps (Ehr.) Kirchn. (containing
+      chromataphores)                                                    42
+
+  12             Coscinodiscus asteromphalus Ehr. (trans. section, after
+      Pelletan)                                                          23
+
+  13-14-15       Transverse section (diagram) of Pinnularia showing
+      straight, oblique and grooved raphes                              101
+
+  16             Transverse section (diagram) of Biddulphia favus
+      showing inner punctate stratum (after Deby)                        31
+
+  17             Transverse (ideal) section of Surirella                124
+
+  18-19          Transverse (ideal) section of Pinnularia, before and
+      after division                                                    101
+
+  20             Transverse section of Nitzschia linearis (Ag.) Wm. Sm. 122
+
+  21             Transverse section (diagram) of Navicula                89
+
+  22             Transverse section (diagram) of Cymbella                60
+
+  23             Transverse section (diagram) of Amphora                 65
+
+
+
+[Illustration: PLATE 40]
+
+
+
+
+
+End of the Project Gutenberg EBook of The Diatomaceae of Philadelphia and
+Vicinity, by Charles Sumner Boyer
+
+*** END OF THIS PROJECT GUTENBERG EBOOK DIATOMACEAE ***
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