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Frontispiece
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THE . BRITISH DIATOMACE~:.
Ie Gas IL
CLXXXVI1 accel
Se sieembe es —_— Fel & West 54, Hatten Carden OOS | Inch. BE
a SO Oars is
OF THE
BRITS DIATOM ACG EA
WITH REMARKS
ON THEIR
STRUCTURE, FUNCTIONS AND DISTRIBUTION ;
AND INSTRUCTIONS FOR
COLLECTING AND PRESERVING SPECIMENS.
BY
THe Rev. WILLIAM SMITH, F.LS.
THE PLATES BY TUFFEN WEST,
MEMBER OF THE MICROSCOPICAL SOCIETY OF LONDON,
“ Naturam maximé admiraberis, si omnia ejus opera perlustraris.”—GALEN.
IN TWO VOLUMES. VOL. I:
LONDON:
PRINTED FOR SMITH AND BECK, 6 COLEMAN STREET, CITY; PUBLISHED BY JOHN VAN VOORST, PATERNOSTER ROW. 1853.
me (ef
FRINTED BY TAYLOR AND FRANCIS, © RED LION COURT, FLEET STREET.
TO
G. H. K. THWAITES, ESQ.,
OF
PERADENIA, CEYLON,
BY WHOSE ENCOURAGEMENT I WAS INCITED TO ENTER UPON THE FOLLOWING INVESTIGATIONS,
AND BY WHOSE AID I WAS ENABLED TO OVERCOME
THE EARLIER DIFFICULTIES OF THE STUDY, I INSCRIBE THESE PAGES,
DESIRING THUS TO EXPRESS MY THANKS, AND
TESTIFY MY ESTEEM,
WILLIAM SMITH.
Lewes, March 1853.
PREFACE.
THe siliceous epiderms of the Diatomacez have, of late years, furnished the microscopist with a series of objects, not merely attractive to the general observer, from the elegance of their forms, but interesting to the more scientific student from the minute complexity of their structure, whose detection and delineation call into requisition the exercise of the most patient observation and the skilful management of the highest powers of his instrument. Much attention has in consequence been drawn to these minute organisms, and the want of some English manual, containing a classified arrangement and description of species, has been ex- tensively felt. The present work has been undertaken to supply this want, and owes its appearance to the enterprise and libe- rality of the eminent opticians whose names appear on the title- page. While securing me from loss, these gentlemen have placed me under no inconvenient restrictions, and have left me at liberty to render the work, as far as possible, a record of the facts at present known with regard to the Diatomaceze. So little, however, has been published upon the subject by English natu- ralists, and my views of structure and classification differ so widely from those of continental writers, with whose works [am acquainted, that I have found it necessary to make the following
pages little else than a record of individual observation. To
v1 PREFACE.
state at length the views of foreign authors, merely to show in what respects I differ from their conclusions, or to detail their systems only to illustrate my own departures from their methods of arrangement, appeared to me less likely to serve the cause of a branch of knowledge yet in comparative infancy, than to place before the inquirer a series of observations for which I could personally vouch, and thus to accumulate facts, at present so scantily supplied, upon which the future student might rest a more complete structure of theory and classification.
How far the present work contains materials new to the Enghsh reader will be understood when I state, that of the 224. species included in the first sub-tribe, not more than twenty have hitherto been recorded by our native observers ; and of the others, a very large proportion are either for the first time described, or can only be doubtfully referred to the outline figures given by Ehrenberg and Kiitzing, and rendered accessible to the English reader in the pages of Pritchard’s History of Animalcules.
But the task T had assigned to myself would have been much less productive of results had I not been aided by the frank and cordial co-operation of fellow-inquirers, who, by the liberal com- munication of specimens from other localities, have enabled me to enrich my record with some of its most beautiful and inter- esting forms. It is my pleasing duty to acknowledge the obli- gations I thus owe to Mrs. Griffiths of Torquay, Dr. Dickie of Belfast, Dr. Greville of Edinburgh, Professor Williamson of Man- chester, Mr. Edward Jenner of Lewes, and M. De Brébisson of Falaise, whose entire herbaria in some cases, or in others ample selections therefrom, as far as relates to the Diatomacee, have been placed at my command. I have, however, to regret that these collections, with one exception, contain but few species in the genera embraced in my first volume, and that in this ex-
ception, which refers to the species from Falaise, the specimens I ;
PREFACE, vil
reached me at so late a period that I have been unable to use them in the nomenclature of my plates, and could only employ them in correcting and enlarging the synonyms given in the text.
For other specimens, and many of them in a living state, I am indebted to gentlemen, whose favours I have recorded under the species they have respectively contributed. Among these fellow-labourers I must not omit a special acknowledgment to my zealous and indefatigable correspondent Chr. Johnson, Esq. of Lancaster, who, by frequent communication of specimens col- lected by himself and Mr. George Smith of Wray, and by the liberal aid of books and translations, has contributed important assistance.
Nor do I wish to leave unnoted the labours of my predecessors, more especially those of Mr. Ralfs and Mr. 'Thwaites, to whom is due nearly all that has been known of our British species of Diatomaceze. How much is owing to the accurate and laborious researches of Mr. Ralfs, will be better seen in my second volume, which will embrace the greater number of the genera to which he has directed his attention.
I have, lastly, to acknowledge the efficient assistance received from my able coadjutor Mr. Tuffen West, whose accurate re- presentations, m every case faithfully drawn from nature, have so materially enhanced the value of my work to the scientific student, and conferred upon it much of whatever value it may possess, in the estimation of the general observer.
As I have not admitted anything into my pages which I have not verified by actual observation, I have abstained from re- cording localities unless specimens have been seen and examined by myself. In the uncertainty which attended the nomenclature of species, and the imperfect means of identification open to the English observer, this course was imperative.
I have departed from the rule in one case only, Arachnoidiscus
Vill PREFACE.
Ehrenbergii, Supp. Plate XXXT. fig. 256, and on that occasion an admirable photograph of the object left me no room for hesi- tation as to the species intended. To avoid confusion and un- certamty in the synonyms, I have also abstained from recording written descriptions, and the references in every case, not other- wise stated, are to the numbers of the plate and figure m the work quoted; and, to preserve uniformity, I have invariably used letters for the plate, and numerals for the figure.
Tt will be seen that I have omitted all mention of the genus Dictyocha, whose forms, familiar to the English collector, have hitherto been classed with the objects described in the present work. ‘This organism has, however, little in common with the true Diatomaceze, and the position and structure of its siliceous skeleton altogether exclude it from the class.
[ have been obliged to defer, until the completion of the plates, all explanation respecting the important function of Reproduction in the Diatomacez, and a detailed examination of the contro- versy respecting the animal or vegetable nature of these or- ganisms ; neither of these subjects could have been fully discussed without a reference to many of the figures to be given in my second volume, and I have thought it better to postpone these topics, however immediately interesting, than to enter upon explanations that must necessarily have been imperfect or unin- telligible.
CONTENTS OF THE INTRODUCTION.
Page
Section [. The Habitats and general Appearance of the Dia- tOMmacen ey Sar Re oo ere yc Oe XI
I]. Structure of the Siliceous Epiderm of the Diatoma- CeousvErustulerse pes icles econ sal eons XLV,
III. Internal Structure and Cell-contents of the Diato- MACCOUSETUSGULCS Ai aehc. ce Geno mu Culn cane ueeeer me 1K LV! Movements of the Diatomacer: “. 2. j.0 2.) XxIL V. Self-division in the Diatomacee . . . . . =. . XXiIV VI. Terminology and Classification . . . . . . . XxXvil
VII. On Collecting and Preserving Specimens of the Dia- tomaces eA. hss) Ce) eh
NE OCT Orne
Section I. Hasitrats AND GENERAL APPEARANCE OF THE DIATOMACER.
‘Tue Diatomaceze are readily distinguished from the Desmidice, the Palmellaceze, and other unicellular Algae, by the possession of an epidermal covering of silex, which renders their forms inde- structible by the ordinary agents of decomposition. They are all exceedingly minute, and require the human eye to be aided by the various appliances of the optician’s art, that their beauti- ful forms may become objects of admiration and study. They inhabit the sea or fresh water, but the species peculiar to the one are never found in a living state in the other locality, though there are some which prefer a medium of a mixed nature, and are only to be met with in water more or less brackish. The latter are often found in great abundance and variety in districts occasionally subject to marine influences, such as marshes in the neighbourhood of the sea, or the deltas of rivers, where, on the occurrence of high tides, the freshness of the water is affected by percolation from the adjoining stream, or more directly by the occasional overflow of its banks. Other favourite habitats of the Diatomaceze are stones of mountain streams or waterfalls, and the shallow pools left by the retirmg tide at the inouths of our larger rivers. They are not however confined to the localities I have mentioned,—they are in fact almost ubiqui- tous, and there is hardly a roadside ditch, water-trough or
xii INTRODUCTION.
cistern which will not reward a search, and furnish specimens of the tribe.
The mdestructible nature of their epiderm has also served to perpetuate the presence of these forms m numerous localities, from which their living representatives have long since dis- appeared. Districts recovered from the sea, im the present or other periods of the earth’s history, frequently contain myriads of such exuvize forming strata of considerable thickness. Such deposits have been found in Bohemia, in the neighbourhood of Berlin, in various districts in Italy, and in several of the American States. The city of Richmond in Virginia is said to be built upon a stratum of Diatomaceous remains 18 feet in thickness, and extensive tracts in the Arctic Regions have been found covered with similar relics of a former vegetation.
Nor are we without examples, though on a less extensive scale, in our own country. ‘The ancient site of a mountain lake in the neighbourhood of Dolgelly, localities of a somewhat similar kind near Lough Island-Reavey, in Down, and Lough Mourne, in Antrim, have furnished large supplies of some of the forms described in the present work. Several deposits of a like kind have been met with in Scotland, and have also contributed to en- rich the present volumes. The extreme minuteness of the organ- isms which have furnished such remains, and the hardness of their material, have rendered the substance formed by their aggrega- tion, a useful agent in the mechanical arts, in which it has been employed to confer a polish upon hard surfaces. It is from this circumstance that the material known as Tripoli derives its value as a polisher of metals; and the Dolgelly deposit has to some extent been employed for a similar purpose.
One of the most singular instances of the preservation of Diatomaceous forms occurs in regard to Guano, so largely im- ported as a manure from Peru and Africa. This material is found to contain a large number of the siliceous coverings of these minute organisms, which have been swallowed by the ma- rine birds frequentmg the spots from which the Guano is pro- cured, have survived the process of digestion to which they were at first submitted, and the ages durmg which they have been imbedded in decomposed or decomposing matter, and now
INTRODUCTION. xill
serve by the beauty of their forms to delight the microscopist, and by the property which their presence imparts to the Guano, to contribute to the fertility of our pastures and the growth of our cereals. It is well known that the latter plants contain a large amount of silica in the structures of their stem and leaves ; it is therefore probable that the value of this manure may some degree depend upon the presence of these minute organic remains, which may thus confer upon the Guano a quality ren- dering it eminently conducive to the healthy growth of such crops.
When occurring in strata of a fossil or subfossil character, as the deposits of Dolgelly, Richmond, and Lough Mourne, the epiderms of the Diatomaceze appear as a white or cream-co- loured powder; but their living masses present themselves as coloured fringes attached to larger plants—or forming a cover- ing to stones or rocks in cushion-like tufts—or spread over their surface as delicate velvet—or depositing themselves as a filmy stratum on the mud—or intermixed with the scum of living or decayed vegetation floating on the surface of the water. Their colour is usually a yellowish brown of a greater or less intensity, varying from a light chestnut in individual specimens, to a shade almost approaching black in the aggregated masses. Their presence may often be detected without the aid of a mi- croscope, by the absence, in many species, of the fibrous tena- city which distinguishes other plants: when removed from their natural position, they become distributed through the water, and are held in suspension by it, only subsiding after some little time has elapsed.
The frustules of the Diatomacez, as the individual organisms have not inaptly been denominated, are either free, adherent, or variously aggregated : in Witzschia, Navicula and others, we have the frustules absolutely free ; m Apithemia, Cocconeis, &c., they are usually adherent. One mode of aggregation is that of a ribbon-like filament of indefinite length, as in Fragillaria, &e. ; another, that of a zigzag chain, in which the frustules cohere only by their angles, as in Grammatophora, Diatoma and others. In some species the Diatom is provided with a gelatinous pedicel or stipes by which it is united with other frustules, and
X1V INTRODUCTION.
maintains a connection with a foreign body; we have this form in Synedra and Gomphonema, &c. In others, again, it is enclosed, with multitudes of its confreres, in a gelatinous or membrana- ceous thallus, as in Schizonema, Hucyonema and their allies, and the aggregation of the frustules in such cases sometimes rivals in form and size the branching filaments of the larger Algz. Upon submitting livmg Diatomacez to a microscopic exami- nation, their forms are found to be exceedingly diversified, though the mineral nature of their epiderm confers upon them a general character which reminds the observer of morganic rather than of vegetable or animal productions. ‘Thus prismatic and quadri- lateral forms are among the most general; linear, crescent, or boat-shaped outlines are not unfrequent ; while indidivuals grace- fully curved ina sigmoid manner, and others resembling minia- ture shields or circular discs, occasionally present themselves.
Srcrion II.
STRUCTURE OF THE StuicEous EprpERM OF THE DIATOMACEOUS FRUSTULE.
To ascertain the true form and structure of the Diatomaceous frustule requires a careful microscopic examination, not only of livmg, but of desiccated or prepared specimens. Indeed it is only after an examination of the latter, that the true character of the living frustule can be understood. I shall therefore commence my description of the structure of these organisms by a reference to frustules which have been deprived of their softer parts, either by submitting them to the action of fire, or to the corrosive influence of an acid.
The epiderm of the Diatom consists of two siliceous plates or valves, usually of the most perfect symmetry. When first pro- duced, these valves are closely applied to each other, and the line of junction forms a suture along which the valves readily sepa- rate during the process of self-division which speedily follows the perfect formation of the cell. It seems to be a law with these organisms, that no portion of the internal cell-membrane can be
INTRODUCTION. XV
exposed to the free action of the surrounding water, without secreting a siliceous epiderm; the moment the valves become separated in the process of self-division, we consequently find that the secretion of a third plate of silex commences. This plate forms a band between the valves, and will for convenience sake be afterwards spoken of as the Connecting Membrane. As self-division is continually going on while the frustules are in a healthy or growing state, it is rare to find a specimen in which the valves are not in some degree separated, and con- sequently in which there is not more or less of a connecting membrane.
But that no such membrane exists on the first production of the frustule is obvious, upon the examination of a specimen in which self-division is just completed, as in Pl. VIII. fig. 59 d; Pl. XVIII. fig. 167 d; and Pl. XXVII. fig. 235 d, compared with Pl. VIII. fig.596; Pl. XVIII. fig. 1696; and Pl. XXVII. fig. 235 4, in which the process has made some advance. The process of self-division will be described hereafter ; the present remarks are intended to show that the Epiderm of the Diatom, strictly speaking, consists of only two parts, the connecting membrane being an addition consequent upon the development which attends the growth of the frustule.
Along the line of suture in disciform or circular frustules, but more generally at the extremities of the valves only, when the Diatom is of an oblong, linear, or elongated form, there exist perforations in the silex, which permit the surrounding water to have access to the surface of the imternal cell-membrane. The formation of silex seems occasionally to be arrested in the neigh- bourhood of these spots, and the connecting membrane is in consequence either wholly or partially interrupted at such places. ‘Thus, after the mternal cell-membrane is removed by acid, when it often happens that the valves fall away from the connecting membrane, the latter separates into two parts, and the frustule has in consequence been described as consisting of four plates.
The interruptions in the siliceous epiderm, to which reference has just been made, are usually apparent as slight depressions at the extremities of the frustule; and the appearances they present have been denommated “ puncta” by Mr. Ralfs. In
XV1 INTRODUCTION.
some species these interruptions are more numerous, being found along the entire Ime of suture, and are often connected with minute canals, hollowed out between the siliceous epiderm and internal cell-membrane, and apparently formed by waved flexures of the epidermal envelope. ‘These are noticed under the genus Epithemia, p. 11. They are very conspicuous in Fpithemia longicornis, Supp. Plate XXX. fig. 247, and form distinctive cha- racters in the genera Surirella and Campylodiscus. I have em- ployed the term “ Foramina,”’ in reference to these perforations in the siliceous epiderm, and the epithet ‘Canaliculi,’ to de- signate the grooves into which they occasionally open.
‘The connecting membrane, being of later formation, is usually less firmly siliceous than the epidermal valves, and rarely pre- sents much complexity of structure. Not so with the valves themselves; we have here the greatest variety of form and diversity of structural arrangement.
These variations in form and structure will be best understood by an inspection of the figures, and will be noticed more par- ticularly under each genus. I shall confine my remarks at pre- sent to a few general characters.
In all, we find the valves presenting a surface of a greater or less degree of convexity. This follows as a necessary conse- quence, from their enclosing, when applied to each other, the space occupied by the internal cell. This convexity is often that of a regularly curved surface, forming a segment of a circle of a greater or less radius. The segment is occasionally that of a perfect hemisphere, and the valves, when applied to each other, form a miniature globe; but more frequently the curva- ture is slight, and extends over a part of the valve only, which then appears as a portion of a hollow tube, closed at one end, and which may be either cylindrical or compressed, triangular or quadrilateral.
The imtimate structure of the valve presents an amazing variety, in every genus, and almost in every species, offering distinct features, which serve as the best and most facile means of distinction and identification. Strize or lines frequently mo- niliform, dots arranged in a radiate or concentric manner, and minute divisions presenting perfectly hexagonal outlines, are
INTRODUCTION. XVil
among the most frequent appearances. Great diversity of opi- nion has prevailed respecting the nature of these markings, and various functions have been assigned to them, as they have been regarded as apertures, protuberances, or depressions. I am, however, disposed to regard them all as modifications in the arrangement of the silex of the valve, arising from the mode of development peculiar in each case to the membrane with which the silex is combined. It is a well-established fact, that all in- crease in vegetable and animal tissues takes place by the pro- duction and addition of cells ; and the law seems to prevail even in the formation of the envelopes of the minute organisms with which we are now concerned. Certainly no one can look at the structure exhibited by the siliceous valves of Zriceratium Favus, PL. V. fig. 44, and those of Lsthmia enervis or I. nervosa, to be given in the second volume of the present work, without feeling assured that he has before him the representation of a cellular membrane, precisely homologous with the epidermal tissues of many vegetable organs. An object-glass of sufficient power and definition shows the same structure in the valves of many species of Plewrosigma; and the generalization is at once forced upon the observer, that the valvular markings in every case arise from modifications of cellular tissue,—a conclusion which a further and closer examination does much to confirm. In no case have I been able to satisfy myself of the existence of perforations in the general surface of the valves ; and the existence of depres- sions or elevations (except in a few cases, when such appearances arise from the wavy outline of the surface,) seems to me to be equally problematical; but no difficulty presents itself to the supposition, that the moniliform strize of Hpithemia, Navicula, and others, the circular markings of Coscinodiscus eccentricus, Plate HI. fig. 38, and the irregular star-like structure of Aypo- discus Argus, Plate IV. fig. 39, are all modifications of cellular tissue ; and even in the costz of Pinnularia and the unresolvable strie of Hupodiscus sculptus, Plate IV. fig. 42, and others, it is not difficult to conceive that we have confluent cells whose union gives rise to the appearance of lines or bands.
With the appearances thus arising from the cellular structure of the tissue with which the silex is combined, we must not con-
b
XVill INTRODUCTION.
found those which are caused by the presence of Canaliculi, to which reference has already been made; nor must we overlook others, which, although connected with the structure of the valve, arise from the absence of cells. Thus m many genera the valve is notably distinguished by the presence of a longitudimal band of silex, free from markings, and widened into small expansions at the centre and extremities, or at the extremities only. ‘This band is simply a portion of the tissue in which the silex is de- posited in a solid mass, and is probably designed to give firm- ness to the valve. At the expansions of this band the silex is still further accumulated, and forms Nodules, which also strengthen the epidermal envelope.
That these expansions are not perforations in the valve, as alleged by Ehrenberg, and acquiesced in by Kiitzing, might be shown in various ways. ‘The internal contents of the frustule never escape at such points when the frustule is subjected to pressure, but invariably at the suture or the extremities, where the Foramina, already described, exist. Nor does the valve, when fractured, show any disposition to break at the expansions of the central le, as would necessarily be the case were such points perforations, and not nodules. Moreover, the central band of silex is itself frequently traversed by a narrow line, which arises from the confluence of a series of cells, which thus form a minute tube; but this tube invariably ends in a rounded ex- tremity at the central and terminal nodules, and does not pass into an opening or aperture in the valve. A reference to Plate XIX. fig. 166. will illustrate these remarks. The bending down of this tube, and the thickening downwards of the silex at the nodules, give the semblance of depression to the surface of the valve at such places. But I am disposed to think that this is merely an optical appearance ; and amy at all events assured that no perforation exists at such poimts, and that the terms applied to these nodules by different authors, implying that they are openings or ostiola, are altogether madmissible.
INTRODUCTION. X1X
Section III.
INTERNAL STRUCTURE AND CELL-CONTENTS OF THE DIATO- MACEOUS FRUSTULE.
I now proceed to describe the living frustule, some of the appearances presented by which can only be understood by a previous acquaintance with the structural character derived from an examination of the siliceous envelope.
A careful study of these organisms in a fresh state is neces- sary to enable the observer to arrive at a correct idea of their true character. The species are lable to material alterations when removed for any length of time from their natural localities ; the lapse of a few days, and sometimes of a few hours, bemg sufficient to modify or altogether change the colour and arrange- ment of the cell-contents, and to suspend the peculiar movements which in many species accompany their living condition. They must, therefore, be examined under favourable circumstances, or our conclusions may be of the most erroneous kind; and a neglect of these precautions has undoubtedly led in some cases to grave errors respecting the structure, and even the nature, of the Diatomaceous frustule. As I look upon these organisms as unicellular plants, I consequently regard the siliceous valves as investing a closed membranous sac or cell. Nor is this a matter of conjecture and analogy only. In some cases I have seen unmistakeable indications of the existence of this membrane, which I have noticed to contract around the cell-contents upon the death of the cell; and in one species, Stawroneis pulchella, Plate XIX. fig. 194, in which the membrane in question appears to possess an unusual degree of firmness, the siliceous valves, after a slight maceration in acid, may be seen to fall away from the internal membrane, and to leave the latter unaltered in form. Moreover, the experiments and authority of Professor Bailey place the existence of an internal membrane beyond all doubt. This acute observer states that, “If hydrofluoric acid is applied to recent Diatomacez, the shell soon dissolves, leaving distinct internal, flexible cell-membranes, retaining the general form of
b2
XX INTRODUCTION.
the shells.” (From Silliman’s Journal for May 1851, quoted in Ann. Nat. Hist. 2nd Ser. vol. viii. p. 157.)
The usual colour of the living frustule I have stated to be a yellow, with a brown or greenish shade of a greater or less m- tensity ; this colour is found to arise from the contents of the cell, which consist of a mucilaginous fluid, in which float numerous minute granules, generally accumulated in thin layers towards the internal cell-walls. When the frustule is so turned that this layer of endochrome is presented edgeways to the eye, the gra- nules appear to be chiefly aggregated into two plates, applied to the opposite sides of the frustule; and when self-division is in progress, and the cell-contents are divided into two portions, such a separation or temporary aggregation of the endochrome must necessarily ensue; but in the simplest condition of the frustule the contents are diffused over the entire surface of the cell-walls, precisely as may be seen in the cells of many of the larger Algze, or of some water plants of a higher order, as in the leaves of Hydrocharis Morsus-rane and others.
The endochrome of the Diatomaceous frustule is not, however, spread with uninterrupted regularity over the entire wall of the cell; at a spot exactly in the centre of the frustule it is usually absent, bemg aggregated in a narrow line or ring around a circular space occupied by a transparent vesicle, the nucleus or cytoblast of the cell, which frequently encloses an evident nucleolus. Nor are we to regard the endochrome as being always confined to the surface of the cell-wall. It is often diffused throughout the entire cavity, in lines radiating from the nu- cleus. Such a disposition frequently occurs in Plewrosigma and others, and is invariably found in Navicula elliptica. (See Frontispiece, fig. CLIT.)
In most species several smaller globules, in addition to the central vesicle, are found occupying certain fixed positions within the cell; these are probably special secretions from the cell- contents, of an oily nature ; and I am disposed to attribute to them the origin of the peculiar odour exhaled from the frustules in the process of burnmg. ‘The number of these globules is frequently four, often placed near the extremities, or, more rarely, clustered around the central vesicle. Professor Kiitzing has ex-
INTRODUCTION. XX1
amined these globules with the greatest care, and has convinced himself of their oily nature. He regards them as representing the amylaceous secretions of the Desmidiez and Confervee, and the starch-granules of the cotyledons of the higher vegetables. (Bacillarien, p. 23.)
A distinct movement of the granular particles of the endo- chrome, closely resembling the circulation of the cell-contents in Closterium Lunula, noticed by My. Ralfs (British Desmidiez, Pre- face, p. xxi.), and which I have frequently detected in the same species, has occasionally fallen under my notice in some of the larger species of Diatomacece.
In Surirella biseriata, Plate VIII. fig. 57, this motion has been more especially apparent ; but I have also observed it take place in Miteschia scalaris, Plate XIV. fig. 115, and Campylo- discus spiralis, Plate VII. fig. 54.
This circulation has not, however, the regularity of move- ment so conspicuous in the Desmidiez, and is of too am- biguous a character to furnish data for any very certain conclu- slons, save one, viz. that the Diatom must be a single cell, and cannot contam a number of separate organs, such as have been alleged to occupy its interior; simce the endochrome moves freely from one portion of the frustule to another, approaching and receding from the central nucleus unimpeded by any inter- vening obstacle.
Of the chemical composition of the endochrome, I am at pre- sent unable to offer a satisfactory analysis. Professor Frankland, of Manchester, who kindly consented to direct his attention to the chemical constituents of these organisms, but whose engage- ments have hitherto prevented him from completing the neces- sary investigations, informs me that a large amount of iron exists in the state of a silicate or protoxide in the siliceous epiderm ; and he attributes to its presence the brown colour which is assumed upon exposing the Diatoms to the influence of a moderate heat, the protoxide of iron, by the gradual absorption of oxygen, bemg converted into brown peroxide of iron, which assumes a redder tinge upon bemg more strongly heated.
Of the behaviour of the endochrome under the influence of certain reagents, | may merely remark at present, that dilute
XX1L INTRODUCTION.
tincture of iodine causes the internal membrane to contract upon the cell-contents, and converts these, from the golden yel- low which they exhibit in some species, into a bright green ; and that a weak solution of sulphuric acid, while it effects the same contraction in the cell-wall, gives to the contents, which have been previously treated with iodine, a dark brown hue. Alcohol, on the other hand, as in the case of vegetable cells in general, dissolves the utricle and its contaimed endochrome, or, at all events, entirely removes their colour, and leaves their siliceous epiderm in a state of perfect transparency. It does not, however, dissolve the envelope in which the frustules of the frondose forms are imbedded, nor the filamentous stipes or gelatinous cushions to which other species are attached.
Section IV.
Movements oF THE DIATOMACES.
One of the most striking circumstances connected with the living frustule, is the smgular motion which most of the free species exhibit.
This motion is of a peculiar kind, being generally a series of jerks, producing a rectilinear movement in one direction, and a return, upon nearly the same path, after a few moments’ pause, by another series of isochronal impulsions.
The movement is evidently of a mechanical nature, produced by the operation of a force not depending upon the volition of the living organisms. An obstacle m the path is not avoided, but pushed aside; or, if it be sufficient to avert the onward course of the frustule, the latter is detained for a time equal to that which it would have occupied in its forward progression, and then retires from the impediment, as if it had accomplished its full course.
There is certamly no character of animality in the movement ; and the observer familiar with the phzenomena of life in the ear- her stages of vegetable existence, is constramed to seek a counter- part in the involuntary motions of the filaments of the Ose7//a- foriee, or of the gemmiparous spores of the vc and Conferve.
INTRODUCTION. XXili
The movements of the Diatomacee appear rapid and viva- cious under the microscope ; but it must be remembered that the high powers usually employed in the observation of these mi- nute organisms magnify their motions as well as their bulk. I have noted the movements of several species with the aid of an eye-piece micrometer and a seconds watch, and found that one of the most rapid, viz. Bacillaria paradora, moved over zooth of an inch in a second; Pinnularia radiosa, one of the slowest, over 3qooth of an inch in the same time; and that the same period was occupied by Pinnularia oblonga m traversing zp yoth of an inch, Mtzschia linearis 335th of an inch, and Plewrosigma strigosum zzooth of an inch. Or, expressing the spaces and times by other units, we find that the most active required some- what more than three minutes to accomplish movements whose sum would make one inch, and the slowest nearly an hour to perform the same feat.
These movements are usually noticed only in the free species of the class, as in those belonging to the genera Navicula, Nitz- schia, and others, and especially in the more minute or younger individuals. Motion is not, however, confined to these, but may at times be detected in other forms, and even the frustules. of attached species, as those of Gomphonema, when forcibly sepa- rated from their stipes, occasionally exhibit an evident tendency to change their position. The movements in the latter are, how- ever, exceedingly languid, and have nothing of the isochronism so notable in the others.
Of the cause of these movements I fear I can give but a very imperfect account. It appears certain that they do not arise from any external organs of motion. The more accurate instru- ments now in the hands of the observer have enabled him con- fidently to affirm, that all statements resting upon the reve- lations of more imperfect object-glasses, which have assigned motile cilia, or feet, to the Diatomaceous frustule, have been founded upon illusion and mistake. Among the hundreds of species which I have examined in every stage of growth and phase of movement, aided by glasses which have never been sur- passed for clearness and definition, | have never been able to detect any semblance of a motile organ; nor have I, by colour-
XX1V INTRODUCTION.
ing the fluid with carmine or indigo, been able to detect m the coloured particles surrounding the Diatom, those rotatory move- ments which indicate, in the various species of true infusorial animalcules, the presence of cilia. I am constrained to believe that the movements of the Diatomaceze are owing to forces operating within the frustule, and are probably connected with the endosmotic and exosmotic action of the cell. The fluids which are concerned in these actions must enter and be emitted through the minute foramina at the extremities of the siliceous valves ; and it may easily be conceived, that an exceedingly small quantity of water expelled through these minute apertures would be sufficient to produce movements in bodies of so little specific gravity.
If the motion be produced by the exosmose taking place alter- nately at one and the other extremity, while endosmose is pro- ceeding at the other, an alternating movement would be the result in frustules of a linear form; while im others of an ellip- tical or orbicular outline, in which foramina exist along the en- tire line of suture, the movements, if any, must be irregular, or slowly lateral.
Such is precisely the case. The backward and forward move- ments of the Vaviculee have been already described ; in Surzrella and Campylodiscus the motion never proceeds farther than a lan- guid roll from one side to the other; and im Gomphonema, in which a foramen, fulfilling the nutritive office, is found at the larger extremity only, the movement is a hardly perceptible advance in intermitted jerks in the direction of the narrow end. The subject is, however, one involved in much obscurity, and is probably destined to remain, for some time to come, among the mysteries of nature, which baffle while they excite mquiry.
Section V. SELF-DIVISION IN THE DIATOMACES.
This process, by which asingle cell is converted into two per- fect cells, is by no means peculiar to the Diatomacez, but pre- vails extensively in the vegetable kingdom, if indeed it be not
INTRODUCTION, XXV
the ordinary mode of increase in all such tissues. Certain it is, that in the great class of unicellular Algze, it is the universal mode of growth and multiplication. It, however, presents several peculiarities in the organisms with which we are now concerned, and is also so readily noted and followed in all its stages in the Diatomacee, that a close observance and clear comprehension of the process in their case may illustrate and guide inquiry in other tribes.
The first step in the process of self-division in the Diato- maceous frustule, is the fission of the internal cell, probably by the doubling-in of its membranous wall, and consequently the separation of the endochrome or cell-contents ; the central vesicle or cytoblast also dividing into two parts, which remove to a little distance from each other; these movements bemg simultaneous with a retrocession of the epidermal valves and the formation of the siliceous connecting-membrane already described. In the centre of the enlarged frustule, in exact apposition to the original valves, and closcly applied to them, there are now formed two new valves, covering the surface of the cell-membranes along the line of fission. The divided portions of the endochrome spread themselves along the membrane which is embraced by the new valves, and there result two half-new frustules, bound together by the connecting-membrane, generated during the process we have described. 'The figures of self-division given throughout the plates will serve to illustrate this description ; and more especially those in Pl. VIII. fig. 59d, Pl. XV. fig. 126 d, Pl. XXII. fig. 216 d.
Durmg the healthy life of the Diatom, the process of self- division is being continually repeated; the two half-new frus- tules at once proceed to divide again, each into two frustules, and thus the process continues. I have been unable to ascer- tain the time occupied in a single act of self-division ; but sup- posing it to be completed in twenty-four hours, we should have, as the progeny of a single frustule, the amazing number of one thousand millions in a smgle month: a circumstance which will in some degree explain the sudden, or at least rapid, appearance of vast numbers of these organisms, in localities where they were, but a short time previously, either unrecognized, or only sparingly diffused.
XXV1 INTRODUCTION.
‘The new valves formed during the process of self-division or- dinarily appear exact counterparts in form and size of the valves of the original frustule ; but a careful examination of the pro- cess in the filamentous species has led me to conclude that a slight enlargement occasionally takes place in the new valves, thus causing a widening of the filament.
This increase is however so small, that in a filament of many hundred frustules, the enlargement is scarcely appreciable. The rapid attenuation represented by some authors in the fila- ments of the Fragi/arie must therefore be attributed to the deceptive appearance presented by a compressed band when slightly twisted, the semblance of attenuation being thus given to the portions which are presented in an oblique direction to the eye of the observer.
The increase in the new valves, although slight, will however sufficiently account for the varying breadth of the bands in the filamentous species, and the diversity of size in the frustules of the free forms, without obliging us to suppose that a growth or aggregation takes place m the siliceous valve when once formed. Starting from a single frustule, it will be at once apparent, that if its valves remain unaltered in size, while the cell-membrane experiences repeated self-division, we shall have two frustules constantly retaming their original dimensions, four slightly increased, eight somewhat larger, and so on, in a geometrical ratio, which will soon present us with an mnumerable multitude containing individuals in every stage, but im which the larger sizes preponderate over the smaller; and such are the circum- stances ordinarily found to attend the presence of large numbers of these organisms.
It is hardly necessary to remind the student acquamted with the general laws of the vegetable kingdom, that this multiph- cation of the Diatomaceous frustule is not a true reproduction of the species, but merely a growth or extension of the original frustule with which we may suppose self-division to originate ; and as the myriads of cells which constitute the entirety of the largest sea-weed, are regarded in their aggregation as forming but one plant, so may we consider the thousand millions into which a single month’s growth has multiplied the original frus-
INTRODUCTION. XXVll
tule, as belonging to the individuality of the first organism in the Diatomaceous chain of being.
With the free species of the Diatomacee the analogy may seem a forced one; but its correctness is at once apparent, if we ascend to more complex combinations in the filamentous and frondose genera, no very obvious difference existing be- tween the union of cells in Fragilaria and those of many spe- cies of the Conferve; or their aggregation in Schizonema, and various forms of the larger Aleze. The most important distinction between the combination of cells in the two cases, is the greater readiness with which the connection is dissolved im the Diato- mace and the retention of mdependent life in each separated cell; but as we descend in the scale to the lower Algw, and approach the Ulvacee or Palmellacee, even this difference dis- appears, and the smallest portion of the frond, even a simple cell, in these forms enjoys the same independent vitality and power of increase as the Diatomaceous frustule.
The increase by self-division in the Diatomacez is therefore not a renewal, but a mere extension of individual life; and the process has been justly defined by Mr. Thwaites, in the analo- gous case of the Palmellacee, as an act of Gemmation rather than Reproduction.
“Tf we duly consider this fact,” remarks this acute and zeal- ous student of nature, “ how much does it exalt the lower tribes of plants in our estimation! since we may contemplate an indi- vidual plant of them not as the single phyton—not as the single frond—not as the single cell—but as the aggregate, it may be, of thousands of these ;—view it occupying as much space, and exercising as great an influence in the ceconomy of nature, as the largest forest tree.” (Annals of Natural History, 2nd Series, vol. u. p. 315.)
Section VI.
‘ERMINOLOGY AND CLASSIFICATION.
The circumstances attendant upon the self-division of the Diatom furnish means for fixing the termmology applied to the
XXVlil INTRODUCTION.
different aspects of the frustule. It would have been desirable to have here adopted the terms employed by former writers, especially by those distinguished authors who have led the way im the study of these organisms; but this course is pre- cluded by the circumstance that these writers have employed terms which imply views of the structure and nature of the Diatomaceous frustule that are now altogether admissible, or at all events at variance with the conclusions of the present writer.
Thus, the terms ventral and dorsal, employed by Ehrenberg, would be clearly inconsistent, if not unmeaning, when applied to the different aspects, or parts of a plant. The terms primary and secondary sides, adopted by Kiitzing and others, are not open to the same difficulty ; but they labour under this objection, that they have not been employed by Mr. Ralfs, the highest English authority upon the subject. I shall therefore adopt the nomenclature of the last-named writer, as the most convenient for the English student, and use the term “front view,” to de- note the aspect of the frustule. when the valvular suture, or the line along which self-division takes place, is turned towards the observer; and the term “side view,” when the centre of one valve is directed to the eye.
Even these terms will require modification when applied to some of the more complex and irregular forms; but im general their meaning will be sufficiently obvious, and special cases will be noticed as they present themselves.
Self-division also supplies circumstances and. distinctions, which appear to me most suitable in the present state of our knowledge, on which to found a generic arrangement of the Diatomacee. ‘The circumstances which accompany the Repro- duction of these organisms are so imperfectly ascertained, and that in so few species, that it is impossible to employ them with advantage in a generic arrangement. Self-division seems to me to come next in order, as a most important function connected with increase and growth, and to supply the necessary variety of phenomena on which to ground our sectional divisions.
I have therefore separated those forms where self-division is accompanied by the secretion of a permanent gelatinous or
INTRODUCTION. XX1X
membranaceous envelope, in which the frustules are subsequently imbedded, from those in which such secretion is altogether absent, or is represented merely by a cushion or stipes, to which the frustules are attached by a small portion of their surface ; and I have placed the latter, as of simpler organization, in my first tribe, arranging the genera belonging to it into sub-tribes, depending upon the permanency or otherwise of the connecting- membrane, another product of the self-dividing process. ‘This enables me to place apart those genera whose species present us with frustules in which the union of the cells is dissolved almost immediately upon the completion of self-division, as well as those where a cushion or stipes still maintains a kind of indirect in- dividuality in the divided frustules, from the genera in which the cells cohere after gemmiparous increase, and by such co- herence form filaments of various lengths and forms, allotting the latter to sub-tribes which respectively present a compressed filament, a zigzag chain, or a cylindrical thread. In the second tribe, mcluding those genera which have frondose forms, I find characters for my sub-tribes in the nature of the frond and the arrangement of the frustules.
I do not propose this arrangement as free from exceptions or even serious defects, but I have adopted it in preference to those hitherto given, as brmging more frequently together forms allied in structure and mode of growth, and as being at the same time more strictly in accordance with the external physi- ognomies of these organisms, and therefore more likely to be apprehended by the inquirer entermg upon the study of this department of nature. A wider study of Diatomaceous forms will doubtless lead to more accurate and more natural generali- zations.
Section VII.
On CoLLECTING AND PRESERVING SPECIMENS OF THE DIATOMACE.
I have already described the various localities in which the Diatomacez ordinarily abound. Supposing the observer to be
XXX INTRODUCTION.
acquainted with their general appearance, it remains for me to point out the method to be observed in their collection, and to furnish the student with a few directions as to their subsequent preservation.
Let him provide himself in the first place with the necessary apparatus. or the field, this includes a good stock of small wide-mouthed bottles, that each gathermg may be kept perfectly distinct ; a long rod or stick, to which can be attached a small muslin net; a cutting hook, of about three inches in length ; and a broad flat spoon: the first, to collect such specimens as float upon the surface, or are held in suspension by the water ; the second, to remove the larger Algze which may be covered with parasitic Diatoms ; and the third, to skim the surface of the mud for those which he at the bottom of the pool.
He will probably find, notwithstanding every care, that his specimens are mixed with much foreign matter, in the form of minute particles of mud or sand, which impair their value, and interfere with observation, especially with the higher powers of his instrument. These substances the student may remove in various ways; by repeated washings in pure water, and at the same time, profiting by the various specific gravities of the Diatoms and the intermixed substances, to secure their separation ; but more particularly, by availing himself of the tendency which the Diatomaceze, in common with all growing plants, possess, of making their way towards the light. The free forms may be thus procured im a tolerably clean state; all that is necessary being, to place the gathering which contains them in a shallow vessel, and leave them undisturbed for a sufficient length of time in the sunlight, and then carefully to remove them from the surface of the mud or water.
Having performed these operations, which a little practice will render comparatively easy and generally successful, the next pro- ceeding is to preserve the specimens in such a manner as to render them suitable for examination by the microscope at any future time. ‘This may be done in various ways, according to the nature of the species and the precise object desired.
The simplest method, and the one most generally useful to the scientific observer, is simply to dry the specimens upon small
INTRODUCTION. XXxl
portions of talc, which can at any time be placed under the microscope, and examined without further preparation ; and this mode possesses one great advantage, that the specimens can be submitted without further preparation to a heat sufficient to remove all the cell-contents and softer parts, leaving the siliceous epiderm in a transparent state. But this method will not preserve the natural appearance of the filamentous, stipitate, or frondose forms ; nor will it satisfy the amateur who desires a specimen for his cabinet, and demands a mounting of a permanent kind and neat appearance.
To meet these requirements, it is necessary that the specimen should be preserved in fluid or balsam. The modes of mounting objects im both these ways are best learnt by the examination of specimens thus prepared; and the manipulation required can only be successfully acquired by practice.
I have never found written or verbal directions of much real value, and shall confine myself to a few hints, which may sup- plement the discernment and patience of the operator, but can- not supersede their presence nor supply their absence.
The walls of the artificial cell for the filamentous and stipitate forms, I invariably form of litharge (protoxide of lead) and japan- ners’ gold-size ; and I attach the thin glass covers with a cement of gold-size, mixing with it a little lamp-black, to give a darker colour to the last coating applied.
The fluid I employ is distilled water, without any mixture whatever, having found all compound fluids not merely unneces- sary, but ijurious.
If the filamentous and stipitate forms are not, however, mounted in a fresh state, the frustules separate from each other, part from their stipes, and lose their characteristic appearance. ‘To remedy these inconveniences, I immerse such specimens as cannot be placed in cells when freshly gathered, in spirits of wine and water—one part of the former to six of the latter, and their attachment to their stipes remains afterwards undisturbed, unless violence be employed to separate them.
In preserving the Diatomacee in balsam, the siliceous valves are the portions alone required. Indeed, it would be imprac- ticable satisfactorily to mount specimens in their natural state
XXXll INTRODUCTION.
in such a medium, as the presence of the cell-contents would prevent the access of the balsam to the interior of the frustule. T'o procure the valves in a separated state, it is necessary to boil the frustules for a few minutes in muriatic or nitric acid; thus removing the softer parts, and dissolving the connexion between the various portions of the frustule. The acid must afterwards be removed by repeated washings, allowing the siliceous mate- rials to settle to the bottom of the vessel after each addition of water: we thus procure the specimens im a proper state. Having poured off the superfluous water, a drop of the fluid containing the Diatomacez is to be placed on the slide, evapo- rated to dryness, and the balsam and cover applied as in the ordinary mode. ‘To avoid the presence of air-bubbles, it is only necessary to use the balsam in a sufficiently fluid state ; and this may be secured by mixing it with ether or rectified spirits of turpentine, taking care entirely to expel the latter by the application of a gentle, but long-continued heat, before applying the glass cover.
With some valves, more especially in those specimens the resolution of whose cellular structure requires the application of the highest powers of the instrument, a different mode of mount- ing is necessary, as the application of balsam obliterates the more delicate markings. Such objects must be preserved in a dry state, without bemg immersed in any medium, and must not only be covered with glass sufficiently thin to allow the approach of a lens of high power, but also placed upon a glass slide, whose thickness will not impede the use of condensing lenses of short focal lengths. These objects are accomplished. by per- forating a wooden or metallic slide, and placing upon the per- forations, which ought to be as large as practicable, a portion of thin glass, to receive the object, cementing this to the slide, and placing over it a cover of glass not exceeding z}oth of an inch in thickness, and thinner if possible. ‘To prevent the admission of moisture, which would ultimately make its way to the object and destroy its value, it is indispensable that the cover should be cemented to the thin glass below. A neglect of this precau- tion will, sooner or later, be followed by the loss, to all valuable purpose, -of the contained specimens.
INTRODUCTION. XXXII
In noticing the usual habitats of the Diatomacee, I have omitted to mention a locality not ordinarily accessible—the deeper parts of the ocean—which can only be reached by the dredge of the more enthusiastic and laborious collector. Many teresting species will reward a search conducted with this unplement. The magnificent Campylodiscus Horologium, P\. V1. fig. 51, was thus obtamed. But these more hidden “ treasures of the deep’ may be reached in an indirect mode, by employ- ing those fishes or molluscs which frequent deep water, as our substitutes for the dredge. Thus, in the stomachs of the crab or lobster, sole or turbot, the scallop or whelk, such organisms are often found; and several species, rarely or never occurring im my usual haunts, have been supplied in abundance by a careful dissection of the above microphagists.
I have also failed to indicate any season as more suitable than another for the researches of the student. I have, how- ever, designedly omitted to do so, as every season is productive of interesting forms. The notes appended to the descriptions of each species, in which I have, when possible, recorded the months mm which the species were collected, will show how perennial is the supply. Weather permitting, the collector may always reckon upon well-filled bottles, provided his rambles are by the sea-coast, or through a district supplied with ponds and streams. I take my leave of him for the present, by recommending to his pursuit a study pregnant with interest and with beauty; which fills the mind with wonder in the con- templation of forms at once so minute and perfect, so humble in their individual capacity, and yet by their numbers and wide diffusion occupying an important position in the organic world, and fulfilling the purposes of Power, Wisdom, and Benignity.
ADDENDA ET CORRIGENDA.
Page 5, line 11, for studied, read stated. 7, line 9, for the genus Diadesmis substitute the genus Achnanthidium.
11, add to the instances of Conjugation in Epithemia, E. Zebra; noticed by Mr. Thwaites in Ann. Nat. Hist., Nov. 1847. :
21, to the description of Cocconeis Placentula, add, Striz 45 in :001”; and to habitat, In Conjugation, Lewes, Feb. 1853.
23, line 5, for Orthosira sulcata, Kitz., read Melosira sulcata, Kutz.
24, to the locality of Eupodiscus crassus, add, Stomach of scallop, Feb. 1853.
25, to the habitat of Eupodiscus sculptus, add, Isle of Dogs, Mr. Roper.
27, Triceratium striolatum? Ehr. Specimens from Mr. Brightwell have satisfied me that this is not 7. striolatum of Ehrenberg; I therefore propose for it the name of 7. undulatum.
29, to the localities of Campylodiscus spiralis, add, Newhaven, Sussex, Dec. 1852, W. Sm.
33, Surirella panduriformis is probably a var. of S. pinnata.
35, for n. sp. annexed to T’ryblionella Scutellum, read W. Sm.
40, add to the habitat of Nitzschia angularis, Poole Bay, Sept. 1849, W. Sm.
51, last line but one, insert a full stop after 42, and read in continuation, Var. 8. Ehr. Inf. xiii. 7, ef seg. ~
SYNOPSIS
THE BRITISH DIATOMACE A.
PRELIMINARY NOTICES.
Tue following List includes the principal works on the Diatomacez which the writer has had the opportunity of consulting. The prefixed abbreviations indicate the contractions employed when reference is made to such works or their authors.
Ag. Syst. Systema Algarum. C. A. Agardh, 1824. Ag. Consp. Conspectus Criticus Diatomacearum. C. A. Agardh, 1830.
Bail. Sound. Microscopic Examination of Soundings off Atlantic Coast of the U.S. By Professor J. W. Bailey (in Smithsonian Contributions to Knowledge), 1850.
Bail. Obs. Microscopical Observations in S. Carolina, Georgia and Florida. By Prof. J. W. Bailey (in Smithsonian Contributions to Knowledge), 1850.
Bréb. Alg. Algues des Environs de Falaise, par MM. De Brébisson et Godey (Mémoires de la Société Académique de Falaise), 1835.
Bréb. Consid. Considérations sur les Diatomées, par A. De Brébisson. Falaise, 1838.
Bright. Inf. Sketch of a Fauna Infusoria for East Norfolk. By T. Bright- well, F.L.S., 1848.
Dick. Ann. Papers in the Annals of Natural History. By Professor Dickie, v. d.
Dillw. Conf. British Confervee. By L. W. Dillwyn, F.R.S. & F.L.S., 1809. Duar. Inf. Ynfusoires, par F. Dujardin, 1841. Ehr. Inf. Die Infusionsthierchen, von D. C. G. Ehrenberg, 1838.
Grev. S.C. F. Scottish Cryptogamic Flora. By R. K. Greville, LL.D. 6 vols., v. d.
Grev. B. F. The Diatomacee in Hooker’s British Flora, vol. 1. P. 1. p. 401 et seg. By Dr. Greville, 1833.
Harv. Man. Manual of the British Algee. By W. H. Harvey, M.D., 1841.
Hass. Alg. Wistory of the British Freshwater Algze. By A. H. Hassall, F.L.S. 2 vols., 1845. B 2
4 PRELIMINARY NOTICES.
Jenn. F. Tun. Flora of Tunbridge Wells. By E. Jenner, A.L.S. (no date). Kitz. Bacill. Die Kieselschaligen Bacillarien, von F. T. Kiitzmg, 1844. Kitz. Phy. Ger. Phycologia Germanica, von F. T. Kiitzing, 1845.
Kitz. Sp. Alg. Species Algarum, von F. T. Kiitzing, 1849.
Lyng. Tent. Tentamen Hydrophytologiz Danice. H.C. Lyngbye. 2 vols.,
1819.
Prit. Anim. A History of Infusorial Animalcules. By A. Pritchard, M.R.I., 1852.
Quek. H. C. Histological Catalogue of the College of Surgeons. By J. Quekett.
Ralfs, Ann. Papers in the Annals of Natural History. By J. Ralfs, M.R.C.S., v. d.
W. Sm. dnn. Papers in ditto. By Rev. W. Smith, F.L.S., v. d. Thw. Ann. Papers in ditto. By G. H. K. Thwaites, v. d.
The letters n. sp. denote that the species to which they are appended is believed to be now for the first time described: W. Sm. that the species has been previously described, or the generic or specific name been altered, by the present writer ; in the latter case the original appellation is given in the list of synonyms. In other cases the writers by whom generic and specific names have been first employed are indicated by contractions, the signification of which may generally be ascertained by a reference to the list of authors given above.
The following abbreviations are adopted in the text :—
F.=Frustule. F. V.=Front view of frustule. S. V.=Side view of frustule. V.= Valve.
1''= English inch.
The letters S. V. and V. may usually be employed indifferently, as in most cases the outline of one valve, when its general surface is turned towards the observer, is identical with that of the side view of the entire frustule.
The letters v.v. following the specific description imply that I have examined a living specimen, and v.s. that I have seen the species only in a dry or fossil state.
The letters which accompany the numbers in the Plates indicate that the figures to which they are attached represent,—a, a side view; 6, a front view ; ¢, a front view of single valve; and d, self-division: when a numeral alone is employed, the figure is that of a side view of a single valve.
The unit of measurement employed is that of an English inch, the magni- tudes being expressed in decimals, thus enabling those who may desire to reduce the dimensions given to the various continental standards (when the values of these are known), to do so by a simple process. The scale in each
PRELIMINARY NOTICES. 5
plate affords a ready means of ascertaining the size of the specimen from which each figure has been drawn ; but where much diversity has been found to exist in the dimensions of the individuals examined, the extremes observed have been noted in the text.
The figures, unless when otherwise indicated on the Plates themselves, are to be regarded as representations of the objects as seen under an amplifying power of 400 diameters, and the details given may be taken as tests of the defining capability of an instrument provided with a magnifying power of that amount. Ina few cases a lens of somewhat higher power has been employed, to resolve and estimate the number of the strize, this designation being applied in every case, not otherwise studied, to the transverse lines or markings of the siliceous valves.
The following British Diatomaceous deposits, recent or subfossil, are those most frequently referred to :—
PETERHEAD Deposit. Described in the Annals of Natural History, Aug. 1848, by Professor Dickie.
Premnay Prat. Described in the Annals of Natural History, Aug. 1848, by Professor Dickie.
Doucetty Eartru. Supplied by Chr. Johnson, Esq., Lancaster, 1850. Noticed by him in the Annals of Natural History, June 1847.
Mart, Co. Down. Supplied by J. M°Adam, Esq., Belfast, 1849.
Loveu Istann-Reavey Depostr. Supplied by the late William Thompson, Esq., Belfast. Described in Magazine of Natural History for J uly 1839, by Dr. Drummond; and noticed in the Annals of Natural History, Feb. 1850, by the present writer.
Lovey Mourne Depostr. Described in Annals of Natural History, Feb. 1850, by the present writer.
Cantyre Prat. Supplied by Prof. Balfour, and noticed in the Annals of Natural History, April 1851 and June 1851.
Raasay Eartu. Fossil Earth from the Island of Raasay, supplied by Prof. Dickie.
A few species are referred to Foreign localities ; these references have been determined by specimens distributed by the London Opticians or known to microscopical observers, and for the genuineness of which the present writer is unable to assign his personal authority ;—such notices may serve in some degree to indicate the wide range of many of our native forms.
SYNOPTICAL ARRANGEMENT
OF THE
BRITISH DIATOMACEZ
Crass CRYPTOGAMIA.
Sup-cuass ALGA. Naturau Orpvper DIATOMACE.
Plant a FrusTuLe ; consisting of a unilocular or imperfectly septate celf invested with a bivalve siliceous epidermis. GEMMIPAROUS INCREASE, by Sevr-Division ; during which process the cell secretes a more or less siliceous ConneEcTING MEMBRANE. ReEpRODUCTION, by ConsuGaTion and the formation of Sporangia.
Trise L. Frustules naked ; not imbedded in gelatine nor enclosed in mem- branaceous tubes.
Sus-TRIBE 1. Connecting membrane deciduous; frustules solitary or during self-division in pairs, rarely in greater numbers, adherent or free, dispersed, or aggregated into a mucous stratum.
22 Genera. Epithemia, Eunotia, Cymbella, Amphora, Cocconeis, Coscinodiscus, Eupodiscus, Actinocyclus, Arachnoi- discus, Triceratium, Cyclotella, Campylodiscus, Surirella, Tryblionella, Cymatopleura, Nitzschia, Amphiprora, Amphipleura, Navicula, Pinnularia, Stauroneis, Pleurosigma.
SYNOPTICAL ARRANGEMENT. 7
Sus-Tr1BE 2. Connecting membrane subpersistent ; frustules after self- division attached by a gelatinous cushion, or dichoto- mous stipes.
7 Genera. Synedra, Doryphora, Cocconema, Gomphonema, Po- dosphenia, Rhipidophora, Licmophora.
Sus-TRIBE 3. Connecting membrane evanescent, or obsolete ; Srustules after self-division united into a compressed filament.
12 Genera. Meridion, Bacillaria, Himantidium, Odontidium, Den- ticula, Fragilaria, Eucampia, Achnanthes, Diades- mis, Rhabdonema, Striatella, Tetracyclus.
Sus-TRiBE 4. Connecting membrane subpersistent ; frustules after self- division united into a zigzag chain.
6 Genera. Diatoma, Grammatophora, Tabellaria, Amphitetras, Biddulphia, Isthmia.
Sus-TrIBE 5. Connecting membrane subpersistent as a siliceous annulus ; frustules after self-division united into a cylindrical filament.
3 Genera. Podosira, Melosira, Orthosira.
Trise II. Frustules invested with a gelatinous or membranaceous envelope. Sus-rriBe 6. Frond indefinite, mammillate ; frustules scattered. | Genus. Mastogloia. Sus-TriBe 7. Frond definite, compressed or globular ; Srustules scattered. 2 Genera. Dickieia, Berkeleyia. Sus-TR1BE 8. Frond definite, filamentous 3 frustules in rows. 3 GeneRA. Encyonema, Colletonema, Schizonema.
Sus-rriBE 9. Frond definite, filamentous ; frustules fasciculated.
1 Genus. Homeeocladia.
ANALYSIS OF THE GENERA.
1. Frustules nude ........... By bs enveloped in ean c or » enclosed ; im laglemeeeras Be 46 2. Frustoles not forming *a filament’... 22. 2+ ci- ae eee 3 - forming a filament, ore win <7 2 4 ers -11-y- idee ee 28 dese rustules freeior ‘adherent? ie 2. 8 oe eee eee Same 4 ft attached by a ‘cushion or, stipes *........2.5--- 7 ees 4. Frustules furnished with canaliculi ......................---- 5 es not iso farmished. ,5...0 25, yk a ee ee 7 5. Valves arcuate or inflated 2... 0.2.....0c2 Jon. coe ces UPD DEaenmee
a
10.
1
12.
13.
14.
», _ Saddleshaped \i.000.4). 022 ich sonaee sees. \CAMPYLOMIS@uR a5) elliptical; ‘ovate or linear, (6.1 ese a ee ee 6
. Valves concave, alee marginal .... 20...) 2... 2): 2 OUR Eee
»» _ plane, ‘alesubmargimal ...0. 02. U.2204-..- ER YVBETONREse
. Valves triangular...) Jonnie ate eye eeaheteeyetei os tye 2a et BCE 33 sOrbicular® y. cree Te ee SP eo & 8 » not triangular nor caylee a favs.oneaey ehetrencwo oie de Se sav alyesisirlated! ss \cc seine ne sia tt lyohietee Rites RM Os ia. HOC One IEam soie @ COLLAR Sra ors orn chaste crm aetna ee As, 9 BEG Urs aoe baRAa sea oce ieueielalegeiet sea ore heed Bp pe L6G ALES 721) Br a Meee A RAG pe ie AAR OE red oda ape ACTINOCYCLUS.
Discs of Valves furnished with processes.............. Evpopiscus. re 5 not ‘so furnished. i. 555% 2.2. oe ee
Valves with a central pseudo-nodule Bor ARACHNOIDISCUS. »» without a central nodule.................. Coscrnoptscus.
Valves arcuate. ... a sesiss otaaiane. AUONOTEEE as 8 WMOLARCUALE Brey ewer ties ckeon es a Site eee. 1G Valves cymbiform. . FO aE ee a asus ees Ud! » elliptical, alla or “Tai. SOAS, 85 5.0 oF SoGe ae oe ee
Nodule subcentral silos SRE Dees COM SED Ris tar 43° e Mmargmal: 27h. seievckaseeee Shon he eo EEE Bae
15.
16.
Gis
18.
19.
20.
21.
22
23.
. Valves having terminal and subcentral nodules
ANALYSIS OF THE GENERA. 9
Brustulesiadherent.. 2. ....5.0... Scticicis na sc Spoveyei tres 212 tC OCCONEIS. a RCC acs ct esis, cio? oi Societe Meh stare aiotal eke ice Rie ete tearcis ore 16 Valves transversely undulated .......... BO ora ont CYMATOPLEURA. eb sOWILMOUL UNGULATIONS: :...: 525m sa sss eee areetererts 2. NS Valves with longitudinal ridges .............- KAtaiuecind oui. 18 Riie PLANE OT CONVEX...) everson er teen rel «m0 reine eiaten 20 Walyes witht atcentralimdce or Keeliiire.< 1. co oo = scl tereareral- 19
»5 with two or more ridges ...:.............. AMPHIPLEURA.
Valves elliptical, deeply constricted .............. 0. AMPHIPRORA. », much elongated ; constriction, if any, slight ...... Nirzscura. Walves siomordinns scsi Sete set ois cits HOS ees ace RU ROSIG NAL
Sy SURG geter toy a esucna oso) ore, Apeccte hate 5 Sake ie DRS a ata he ey 124 Wakes Satin @amadail moll 255 6550 cocno0 noodsasg0ce sons 72 » with central nodule dilated into a Stauros ...... STAURONEIS. Valveshstriated sci s eg the. s auteur ey eyaicne arr ae ekore NAVICULA. BME COSUALCU 2i2)s,0 Aa coctoine cicke sioner sions Sate a eee PINNULARIA. Frustule linear or much elongated .................... SYNEDRA.
3 ellipticaloricymbitonm ys. 22 ee heats eer nts oe 24 5 CUNEATE Ae sero e e nas et soni Se ctaiee Dinan Pilar ee
ey aor Ys CoccoNEMA. +) without nodules). 0/55. 0202 2c. oe. DORYPHORA,
25. Valves with a nodule in the centre and at each end.... GoMPHONEMA. Peae OW it OMEN O CULES race nee Sty) SACGED crea ccemaes OPN os Ara era ae 26 ZGeesupesionsoleteyor, very, SHOt= 1. hacjas 4-00 cise oo ee PopOSPHENIA. siap KE LOMR AEM sy ee era ror clal ela kits tas WAtee Staten meee ed fem SuUDeS) LUM OTIN) = -tneites) 6 = 2) ele =1]s.ai4 = ve'e s!eieie) ciat= <eeloiets RuIPIDOPHORA.
28.
30.
31.
32.
MAMANCTASSALC Parte tele a Hee eau tc delorsic ics ie ele. LAL CMO PHO Rate
Milamentcompressed, contmuoust).. 45-0 5 ey Pacers eee iO,
Ae ZS 7Aes CLAN pri ae sone stele athasotes sees eiewee. at oy olay wisi OD ‘. Gylindrical 8. yes sanct 5 ye ose ce eee einte a lofetet eaten 44 me Pulament spirale ...c7a a). erste eyes acc s + oes NEBR EDIONG ie COU are ee ee es eet BACILLARIA. Ps Strate Gvvepeye te por eicie el ete icici eerselehate tc ee eee 30
Erustulecwithyimternal septa. giana a5 cis: oc ore + re epi 5 WItHOULESED beers, 1 a)staye <i'4 cus ote ies) aleertions cle eee 31
Valves with central and terminal nodules .............. D1AprEsmis. » without nodules.:.... Sn re ee a eRe ee na OD
Frustule curved on Front View.................... ACHNANTHES. pee LOD Onedony ErOntaViewWa cc ce «sector teeter tty lier: mers 33
10
ANALYSIS OF THE GENERA.
SaneVAlWES AFCUALE.'. cit) eee Sch, ee .... HIMANTIDIUM. ap) < BITMISDL © Go". 2 ent Se eee ee 34
34, ; Valves with ia'central smus .)......4.e.40aca. lo eee Eucampta. » without a sinus.... oF e's 2 eg nbele) ateabyeheyay el s:'eiS «1 s/uncee eine ae
3d. Valves delicately striated ....:. ..0e.c05 ne bans eek. FRAGILARIA. 3 adistinethy costate <..>.- 42a ee ee «oti ee
36. Frustules united into a lengthened filament .......... OponTIDIUM. * few, scarcely forming a filament .......... -- DENTICULA.
37- Erustules/compressed, =... . 0... -2.-9-. 4. see she! eisie fale eee 38 - mflated os ee he beineccaeeee ce sees nae
35.) tilamentitenacioussry--4. 2. ee ee ee Sales rere RHABDONEMA. AA not tenacious........ steso apa note Ure ape eee STRIATELLA.
39. Frustules with internal septa .......... 0: sis\ais wits: os See 40 os without Septa 2. scott. 00 mines > cane ce «ow een
BO: WSentes Waves 7k sr ctarnc wae Mey ie eee ee GRAMMATOPHORA. gay os SUPA ye iy ea kero eRe, ee ee TABELLARIA.
41. Frustules square or rhomboidal.................... AMPHITETRAS. “ compressedie. ae eee a seis eke iev'eseis ss oe 42
f2-) Brustules) prismatic ee, ice inet eae nee ae eee Diatoma. a6 Subeylindrical yl .28 2° 2 ia-cateee eee 43
43. Angles of frustules rounded, slightly produced ............ IstHMIA. Se Ch yproduceda ls er eee Sty acre eae BippULpHIA.
A4- Hilament (of few dtrustules'95.. .2 5/02) ei. snes PopostrRa.
45.
46.
48.
49.
50.
a mumerous frustules £2. ....2..... 0) oe ee
Frustules with rounded extremities................ .... MELOSIRA. 55 truncated 7.2.80 eee en OrTHOSIRA.
Prond indefinite: e022 wer) eee eee ee MAstToGuora. Sp RMMLCHDILOH IAS tes, Sica, Ons. ik ben cee Nl ct Oe 47
se Hrondycompressed ee sey en ie eee any ee pen ee DicktieEIA.
a) lobular. Be eee cre: Ask eeags oe) IDET ay. © Wilamentous. 17... e sk ee ee eee 48
Brustules in rows) aks ee ot kee a ee 49 is fasciculated |. : 04)... 2 sees elec ecee dds ELOMC@OCiiae Frustules those of a\@ymbella.......:.....0022255 oh ENCYONEMA. ys Ps Navieula. o's 55%. c<lc4inc te Coe eee ee 50 Filaments simple axe: Ae ne ee eee CoLLETONEMA.
* branched.) -ceesucor eee a ee es.. SCHIZONEMA.
THE BRITISH DIATOMACE#.
Genus 1. EPITHEMIA, Aiitz.
Frustules adherent, quadrilateral ; valves arcuate, furnished with trans- verse canaliculi.
A section of the frustule in the present genus would present an outline of varied form, either elliptical or quadrilateral, or that of two nearly perfect circles united by an oblong isthmus; the shape of the frustule in the latter case may be compared, as it has been done by Meneghini, to that of a coffee berry, or more correctly to a grain of wheat, but in no case would the section present a trapezoidal outline, the valves being always parallel or equidistant. This genus, as the name implies, is characterized by the adherence of its frustules to Algze of a larger growth. This character is true of most of the species, and even where not strictly applicable, as in E. gibba and others, we detect a disposition to rely on a foreign body for support, their frustules being usually imbedded in the mucus of some member of the family of the Palmeilacez.
The transverse costa, so conspicuous in some species, I regard as minute canals, which convey the nutrimental fluid to the surface of the internal membrane. They are not modifications of the cellular structure of the siliceous epiderm, otherwise, the striz would not pass, as they do, uninterruptedly over the entire surface of the valve.
Conjugation, and the formation of Sporangia in this genus, have been noticed by Mr. Thwaites in E. turgida and E. gibba, by myself in these species and in E. Sorex.
ie, BRITISH DIATOMACE.
1. Epithemia Hyndmanii, JV. Sm. F. V. inflated; V. much and regularly arched, extremities rounded, not recurved; striz moni- liform, 16 in 001”; canaliculi inconspicuous, 9 in 001". Length of F. °0025" to -0076". v.s.
W. Sm. Ann. 2nd Ser. vol. v. p. 124.
Fresh water. Lough Mourne Deposit, Cantyre Peat. iPlatesat':
2. Epithemia turgida, /V. Sm. F.V.somewhat inflated ; V. slightly arched, extremities suddenly attenuate, obtuse ; striz moniliform, 21 in :001"; canaliculi distinct, 12 in 001". Length -0026" to 0062". v.v.
Epithemia Vertagus, Kitz. Bacill. xxx. 5. sic. cl. De Brébisson in litt. cum specim.
Eunotia turgida, Ebr. Inf. tab. xiv. 5. xxi. 20a. Quek. H. C. xu. 5. In Conjugation, Thw. Ann. vol. xx. pl. iv. Prit. Anim. xiv. 1-8.
Cymbella turgida, Hass. Alg. pl. ec. 7.
Fresh water. Near Aberdeen, Dr. Dickie. Wareham, Lewes, May 1850, &e., W. Sm. Lough Mourne Deposit, Dolgelly Earth, Cantyre Peat and Peterhead Deposit.
Plate I. 2. Frustule with endochrome, Frontispiece, vol. i. fig. IT.
3. Epithemia granulata, Kitz. F.V. linear; V. slightly arched, linear, otherwise like the last. Length :0033” to 0081". v.s.
Kitz. Bacill. v. 20. Hunotia granulata, Ehr. Inf. xxi. 20 p. Fresh water. Lough Mourne Deposit. Plate I. 3.
4, Epithemia Zebra, Kiitz. V. equally arched; F.V. linear; ex- tremities of V. gradually attenuate; stria punctate, 33 in 001"; canaliculi few, 8 in 001". Length :0016" to 0035". v.v.
Kitz. Bacill. v. 12. Hunotia Zebra, Ehr. Inf. xxi. 19. Cymbella Zebra,
Hass. Alg. c. 8. Fresh water. Wareham, Lewes, &c., Aug. 1850, W. Sm.
Plate I. 4.
5, Epithemia Argus, WV. Sm. fF. resembling the last; foramina conspicuous on the F. V. Length :0013” to‘0021". v.v. Epithemia alpestris, Kitz. Sp. Alg. p. 2. ad spec. authent. que misit cl, De Brébisson, Jan. 1853. Prit. Anim. xxiv. 11. Fresh water. Near Aberdeen, Dr. Dickie. Plate I. 5.
BRITISH DIATOMACE&. 13
6. Epithemia ocellata, Kitz. F. V. inflated, extremities of V. rounded, foramina large. v.s.
Kitz. Bacill. xxix. 57. Fresh water. Wray near Lancaster, Mr. G. Smith. Cantyre Peat. Plate I. 6.
7. Epithemia longicornis, Ehr. F. V. inflated, extremities obtuse ; dorsal ridge of V. somewhat angular; foramina few, large; striz 27 in :001". Length -0033" to :0058". v.v.
Ehr. in Prit. Anim. xxiv. 6-9.
Fresh water. Isle of Arran, mixed with Petalonema alatum, Berk. col- lected by Professor Walker Arnott, Aug. 1852.
Supp. Plate XXX. 247.
8. Epithemia alpestris, /V. Sm. F. V. linear; V. recurved at the obtuse extremities ; foramina large; striz 27 in ‘001". v.s.
Kiitz. Bacill. v. 16? Fresh water. Katefield near Lancaster, Mr. G. Smith, April 1851. Plate I. 7.
9. Epithemia proboscidea, Kiitz. FF. V. inflated; V. recurved at the extremities; canaliculi large; foramina inconspicuous ; strize 20nmi-OOL > wiv.
Kitz. Bacill. v. 13.
Fresh or brackish water. St. Ouen’s Pond, Jersey, Aug. 1852, W. Sm. Raasay Earth.
Plate I. 8.
10. Epithemia Sorex, Kiitz. F.V. inflated; V. attenuate, slightly recurved at the extremities, dorsal line highly arcuate ; canaliculi few, minute; striz 33 in ‘001". Length :0009" to 0013". v.v.
Kiitz. Bacill. v. 12.
Fresh or brackish water. Lewes, May 1850, W. Sm. Lough Mourne Deposit, Cantyre Peat, &c. (New Zealand.)
Plate I. 9. Frustule with endochrome, Frontispiece, vol. i. fig. IX.
14 BRITISH DIATOMACE.
11. Epithemia Musculus, Wiitz. V. regularly and highly arcuate, extremities acute; canaliculi distant; strize 40 in -001". v.v.
Kiitz. Bacill. xxx. 6.
Brackish water. Poole Bay. “ Little Sea,” Dorsetshire, Aug. 1848. Near Lewes, Sussex, Sept. 1850, W. Sm.
Plate I. 10.
12. Epithemia Westermanii, Kiitz. FF. V. elliptical; V. arcuate ; canaliculi distinct; striz faint, 40 in :001". Length -0008" to SOO SS OiveNs
Kitz. Bacill. v.12? Eunotia Westermanii, Ehr. Inf. p. 190. taf. xiv. 6? Brackish water. Near Lewes, Oct. 1850, W. Sm. (Ceylon, Mr. Thwaites, Nov. 1851.) Plate Ts U0.
13. Epithemia rupestris, n.sp._ F. V. elliptical-lanceolate; V. acute, slightly arcuate; canaliculi distant, 6 in ‘001" ; striz faint, 42 in 001". Length 0012" to :0023". v.v.
Fresh water. Backsbottom near Lancaster, Mr. G. Smith, April 1851. Plumpton, Sussex, April 1852, W. Sm. Aberdeenshire, Dr. Dickie. Killi- crankie, Mr. P. Grant. Raasay Earth.
Plate I. 12.
The above species first fell under my notice in a gathering made by Mr. G. Smith from the surface of a rock moistened with water in the habitat I have mentioned ; its frequent occurrence in other localities shows that it is widely distributed in subalpine districts. Together with the species last described, and the three which follow, its valves present a peculiar form : their convexity is so considerable, that a transverse section of the frustule would furnish an outline not unlike the figure 8, owing to which circumstance a side view is with difficulty obtained, the frustules naturally presenting their broadest surface to the eye.
14. Epithemia constricta, n. sp. F. V. elliptical with a more or less distinct constriction ; V. acute, much arched ; canaliculi distant, 8 in 001"; striz 30 in :001". Length :0012" to 0026". v.v.
bb)
“Ep. constricta, Brackish water. Excet, Sussex, March 1852, WV. Sm. Supp. Plate XXX. 248.
cl. De Brébisson in litt. eum specim.
BRITISH DIATOMACE. 15
15. Epithemia gibba, [iitz. IF. V. linear, slightly inflated at centre and extremities ; S. V. linear, obtuse; striz 36 in ‘001"; canaliculi 15 in ‘001". Length :0033" to -0104". _ v.v.
Nav. gibba, Ehr. Inf. xiii. 19. Hass. Alg. cii. 4.
Ep. gibba, Kitz. Bacill. iv. 22.
Eunotia gibba, Prit. Anim. xv. 27. In Conjugation, Thw. Ann. vol. xx. pl xxu. Fi.
Fresh water: frequently entangled in the mucus of Sorospora virescens, Hass. Wareham, Aug. 1847. Lewes, Oct. 1850, W. Sm. Lough Mourne Deposit. Peterhead ditto. Near Aberdeen, Dr. Dickie. Rescobie, Mr. P. Grant. (San Fiore, Italy ; Ceylon, 1851, Mr. Thwaites.)
Plate I. 13.
16. Epithemia ventricosa, Kiitz. F. V. elliptical, slightly con- stricted at the ends; V. with acute extremities ; striae and cana- liculi as in the last. Length :0009" to :0018". v.v.
Kiitz. Bacill. xxx. 9. Nav. gibba, Ehr. Inf. taf. xii. fig. xix. 4.
Fresh or brackish water. ‘ Brooks” near Lewes, Oct. 1850. St. Ouen’s Pond, Jersey, Aug. 1852, W. Sm. Near Aberdeen and near Belfast, Dr. Dickie. Peterhead Deposit.
Plate I. 14.
Genus 2. EUNOTIA, Lhr.
Frustules free, oblong; valves arcuate, with terminal nodules and convergent striz.
Closely allied to the former genus, but easily distinguished by the absence of canaliculi, the delicacy of the strize and the dorsal ridges with which most of the species are provided. The F. V. is also uni- formly linear, and the connecting membrane less fully developed than in many of the Epithemia. Isolated frustules of Himantidium might be confounded with the present species, but Ewnotia never forms a tenacious filament, though several frustules may sometimes be found united ; the genera are however closely allied, and with difficulty distinguished from each other.
1. Eunotia Arcus, W.Sm. V. regularly arcuate, acute, with a slight constriction at each extremity, and inflation in the centre of
16 BRITISH DIATOMACE.
the concave margin; strie delicate, 36 in 001". Length :0012” to 0029". v.v.
Navicula Arcus, Ehr. Inf. xxi. 10. Cymbella? Arcus, Hass. Alg.c. 6. Ce- ratoneis Arcus, Kiitz. Bacill. vi. 10.
Fresh water. In boggy pools, Dorsetshire, Jan. 1849, W. Sm. Wray near Lancaster, Jan. 1852, Mr. Geo. Smith. Mountains in Forfarshire, Dr. Dickie.
Plate II. 15. Frustules with endochrome, Frontispiece, v. i. fig. XV.
2. Eunotia gracilis, n.sp. V. arcuate, extremities recurved ; striz delicate, 42 in ‘001". Length 0006" to :0018". v.v.
Fresh water. Wareham, Sept. 1849, W.Sm. Jack’s Wood Spring, Tun- bridge Wells, Mr. £. Jenner.
Supp. Plate XXX. 249.
3. Eunotia monodon, Hhr. V. regularly arcuate, obtuse, extre- mities slightly produced; striz 34 in ‘001". v.s.
Ralfs, Ann. vol. xii. pl. xiv. 1.
Fresh water. Ben M° Dhui, at an elevation of 3000 feet, Mr. P. Grant. Aberdeenshire, Dr. Dickie.
Plate II. 16.
4, Eunotia diodon, Ehr. V. with two dorsal ridges; striz 32 in OO!) 2 evs.
Ehr. Inf. xxi. 23. Ralfs, Ann. vol. xiii. pl. xiv. 2. Hass. Alg. xevi. 6. Kutz. Bacill. v. 24.
Fresh water. Aberdeenshire, Dr. Dickie. Ben M° Dhui, Mr. P. Grant. Plate II. 17.
5. Eunotia triodon, Hhr. V. with three dorsal ridges; strix 40 in :001". Length :0015" to 0026". v.s.
Ehr. Inf. xxi. 24. Prit. Anim. iii. 164. Hass. Alg. xevi. 7. Kiitz. Bacill. Vin PAD
Fresh water. Ben M* Dhui, at an elevation of 3000 feet, Mr. P. Grant. (Lapland. )
Plate II. 18. 6. Eunotia tetraodon, Ehr. V. with four dorsal ridges; striz 24 in 001". Length :0015" to :0022". v.v.
Ehr. Inf. xxi. 25. Ralfs, Ann. vol. xiii. pl. xiv. 4. Hass. Alg. xevi. 8. Kitz. Bacill. v. 26.
BRITISH DIATOMACE&. 17
Himantidium tetraodon, Bréb. in Kitz. Sp. Alg. p. 10. ad spec. quee misit amic. De Brébisson, Jan. 1853.
Fresh water. Ashdown Forest, Sussex, Aug. 1850, W. Sm. Curwen Hill, Lancashire, Mr. G. Smith, June 1851. Quernmore, Lancashire, April 1852, Mr. Johnson. Mountains in Aberdeenshire, Dr. Dickie. Dolgelly, Mr. Ralfs. Dolgelly Earth. Peterhead Deposit. (Manchester, Mass., com- municated by Prof. Williamson.)
Plate II. 19.
7. Eunotia Diadema, Hir. V. with six dorsal ridges; stria 30 in 001". Length 0016" to -0024". v.s.
Ehr. Inf. xxi. 27. Kiitz. Bacill. v. 28. Fresh water. Dolgelly Earth. Plate II. 20.
Genus 3. CYMBELLA, 4y.
Frustules free, cymbiform ; valves striated, with a submedian line and central and terminal nodules.
Many frustules of Cocconemata detached from their stipes bear so close a resemblance to those of the Cymbelle, that a discrimination can hardly be relied upon which depends solely upon the observation of prepared specimens. In a living state, the presence of a stipes at once removes such frustules from the present genus. Cymbella fre- quently forms a more or less distinct stratum, the frustules being re- tained in their position, even when exposed to a rapid current, by the presence of a delicate pellicle of mucus.
1. Cymbella Ehrenbergii, Kiitz. V. elliptical-lanceolate, extre- mities slightly produced, obtuse; striz distinct, 15 in <OOM: Length :0028" to 0054". v.s.
Kiitz. Bacill. vi. 11. Navicula inequalis, Ehy. Onf. xiii. 18. Prit. Anim. 11. 154.
Fresh water. Living, in Lough Mourne, Sept. 1849. Peterhead Deposit. Lough Mourne Deposit. Premnay Peat. Marl, Co. Down. (Near Manchester, Mass., communicated by Prof. Williamson. Very abundant in fossil earth, San Fiore, Italy.)
Plate II. 21.
18 BRITISH DIATOMACEA.
2. Cymbella cuspidata, Kiitz. F. smaller than the last, extremities prominent, somewhat acuminate ; striz indistinctly moniliform, 30 in :001". Length -0012" to 0031". v.s.
Kitz. Bacill. i. 40.
Fresh water. Quernmore near Lancaster, April 1852, Mr. Johnson. Wray near Lancaster, Oct. 1852, Mr. G. Smith. Lough Mourne and Peterhead Deposits. Premnay and Cantyre Peats. (Nova Scotia.)
Plate 22:
3. Cymbella affinis, Kiitz. V. elliptical-lanceolate, extremities slightly produced; striz faint, 30 in :001". Length -0009" to ‘OO1b" 5) vive
Kiitz. Bacill. vi. 15. ad spec. authen. quee dedit amic. De Brébisson.
Fresh water. Parham, Sussex, Feb. 1844, Mr. Jenner. Tford, Sussex, April 1852, W. Sm. Marl, Co. Down, and Dolgelly Earth.
Supp. Plate XXX. 250. Frustule with endochrome, Frontispiece, fig. CCL.
4, Cymbella maculata, Kiitz. Larger segment of V. convex, smaller with a slight inflation in the centre, extremities obtuse ; striz 27 in 7001". Length :0008" to :0015". v.v.
Kiitz. Bacill. vi. 2?
Fresh water. River Frome near Wareham, Dorset, March 1848, W. Sm. Cantyre Peat and Peterhead Deposits.
Plate II. 23.
5. Cymbella Helvetica, Kitz. F. V. linear, slightly arched; V. elongated, segments as in the last, extremities acute; striz 24 in 001". Length °0016” to :0031". v.v.
Kitz. Bacill. vi. 13? Prit. Anim. xvii. 24-28.
Fresh water. River Ouse near Lewes, W. Sm. Peterhead Deposit. Near Aberdeen, Dr. Dickie.
Plate II. 24.
6. Cymbella Scotica, n.sp. V. narrow, elongated, smaller segment straight, extremities acute ; striz 32 in ‘001". Length 0012" to 0027/0. aves Fresh water. Pass of Killiecrankie, very plentiful, M7. P. Grant. Dolgelly
Earth.
Plated 25.
BRITISH DIATOMACE. iS,
Genus 4. AMPHORA, Fir.
Frustules free, or adherent ; valves cymbiform, with a central marginal nodule.
The valves in this genus are exceedingly convex, closely resembling those of Epithemia rupestris, and the section of the frustule is the same as that which I have described under that species. It is pro- bable that most of the Amphore are at first adherent, but they are usually found detached, and sparingly diffused among other Algze.
1, Amphora ovalis, Kiitz. F. V. elliptical, internal margin of V. inflated at the nodule; striz moniliform, distinct, 24 in ‘001". Length :0012" to :0038". v.v.
Kiitz. Bacill. v. 25 & 39. Nav. Amphora, Ehr. Inf. xiv. 3. Prit. Anim. tipo.
Fresh water: frequent. Lewes, April 1852, W. Sm. Lough Mourne De- posit. Peterhead Deposit, &c.
Plate II. 26. Frustule with endochrome, Frontispiece fig. XXVI.
2, Amphora affinis, Kiitz. F. V. oblong, with round or truncate extremities ; strie distinct, 27 in ‘001’. Length -0016" to °0022". v.v.
Kiitz. Bacill. xxx. 66.
Brackish water. Near Lewes, Sussex, Feb. 1852, W. Sm. Plate ITI. 27.
3. Amphora hyalina, Kitz. F.V. elliptical, acute; V. imperfectly siliceous, longitudinally rugose; striz obscure. Length -0021" to 0032". v.v.
Kutz. Bacill. xxx. 18.
Brackish water. Coast of Sussex, Nov. 1850, VW. Sm. Near Lancaster, Mr. Johnson.
Plate ITI. 28.
4, Amphora salina, n.sp. F. V. elliptical, truncate, extremities C2
20 BRITISH DIATOMACE.
slightly produced ; V. scarcely siliceous; strize 64in ‘001". Length 0008" to :0016". v.v.
Brackish water. I=ford, Sussex, Sept. 1852, W. Sm. Supp. Plate XXX. 251.
5. Amphora? tenera, WV. Sm. F. V. oblong, extremities round or truncate; V. scarcely siliceous, longitudinally rugose; striz 62 in 7001". Length :0015" to 0025". v.v.
Amphora lineolata, Kiitz. Bacill. v. 36. ad specim. authen. quae communicavit cl. De Brébisson.
Marine. Formsathin pellicle on stones, &e. Seaford, May 1850. Lancing, Nov. 1852, W. Sm.
Supp. Plate XXX. fig. 252.
6. Amphora membranacea, n. sp. F. V. elliptical, with rounded extremities; V. scarcely siliceous, with a central transverse band ; striz very faint, 80 in:001". Length :0013" to :0030". _ v.v.
Brackish water. Poole Bay, Sept. 1848. Sussex, Sept. 1850, W. Sm. Near Belfast, Dr. Dickie. Near Harwich, Mr. Brightwell.
Plate IJ. 29.
7. Amphora? costata, n.sp. V. longitudinally costate, costze marked with a double line of moniliform puncta; extremities produced. Length -0020" to :0027". v.s.
Marine. Poole Bay, Sept. 1851, W. Sm. Supp. Plate XXX. 253.
8. Amphora minutissima, n.sp._F. V. elliptical or oval; V. marked with a transverse band ; striz 64 in ‘001". vv. :
Fresh water. Parasitic on Nitzschia sigmoidea. Near Lewes, Dec. 1850 and
Oct. 1852, W. Sm. In ponds near London, parasitic on Nitzschia linearis, Mr. Shadbolt, Mar. 1851.
Plate II. 30.
BRITISH DIATOMACE. 91
Genus 5. COCCONEIS, Ehr.
Frustules adherent, disciform ; valves elliptical, plane, with a median line and central nodule.
In this genus the frustules are closely adherent by the surface of one valve to larger Algze, and are usually detached with difficulty. The markings of the lower are less intense than those of the upper surface, but in other respects the valves are symmetrical, and Mr. West informs me that he has found the absence of a central nodule in the lower valve, as noted by some writers, by no means a constant cha- racter.
1. Cocconeis Pediculus, Hhr. FF. arched; V. elliptical, somewhat angular; disc delicately striated ; striz 40 in ‘001". Length :0008 to 0014". v.v.
Ehr. Inf. xxi. 11. Kutz. Bacill. v. 9.
Fresh water. Frequently attached to Cladophora glomerata. Lewes, Aug. 1851; Wareham, Sept. 1851, W. Sm. Lough Mourne Deposit. Peterhead Deposit, &e.
Plate III. 31. Frustules with endochrome, Frontispiece fig. XXXII.
The strize on this species are seen by a higher power as lines, concentric with each extremity of the valve.
2. Cocconeis Placentula, Hir. FF. plane, valve elliptical, disc striated. Length 0011" to :0016". v.v.
Ehr. Inf. p. 194. Ebr. in Kiitz. Bacill. xxviii. 13.
Fresh water: frequent. Wareham, July 1849, W. Sm. Lough Mourne and Peterhead Deposits. Cantyre Peat and Dolgelly Earth.
Plate III. 32.
3. Cocconeis Thwaitesii, V7. Sm. F. arched; valve constricted towards the obtuse extremities ; median line sigmoid; dise faintly striated ; stria 72 in -001". Length :0009" to :0013". v.v.
Cymbella flewella, Kiitz. Bacill. iv. 14. Achnanthidium flewellum, Bréb. in
Kutz. Sp. Alg. p. 54. ad specim. authen. que communicavit cl. De Brébisson, Jan. 1853.
Fresh water. Near Bristol, May 1848, Mr. Thwaites. Mountains in
pe, BRITISH DIATOMACE. Forfar, at an elevation of 2800 feet. Near Aberdeen and near Belfast, Dr. Dickie ; Rescobie, Mr. P. Grant. Marl, Co. Down, Xe.
Plate III. 33. d. outline of ditto in S. V.
4, Cocconeis Scutellum, Hh. V. orbicular or elliptical; striz concentric with extremities, moniliform, 18 in :001". Length 0006" to ‘0016". v.v.
(. Nodule dilated into a Stauros.
Ehr. Inf. xiv. 8. Kiitz. Bacill. v. 6.
Marine. Very common, and exceedingly variable in size and outline.
Plate III. 34. 3, Supp. Plate XXX. fig. 34.
5. Cocconeis Grevillii, n.sp. V. oval, furnished with transverse canaliculi; striee moniliform, 15 in ‘001”. Length -0008" to :0025". V.S.
Quek. H. C. pl. xii. 19?
Marine. Attached to Phyllophora rubens, Sidmouth, communicated by Dr. Greville. Hastings, Mr. Shadbolt. Poole Bay, W. Sm. (Algoa Bay, South Africa. Ichaboe Guano.)
Plate II. 35 a. lower valve ; 35 a*. upper valve ; 35 a'. view of upper valve from within.
6. Cocconeis diaphana, n.sp._V. eliiptical, scarcely siliceous, dia- phanous; striz obscure. Length -0012" to -0018". v.v. {&. Nodule dilated into a Stauros.
Marine. Sidmouth, Miss Cutler, communicated by Dr. Greville. Pontac, Jersey, Aug. 8, 1852, W. Sm.
Supp. Plate XXX. 254.
Genus 6. COSCINODISCUS, Ehr.
Frustules free or adherent, disciform ; valves plane or slightly convex with a cellular structure.
This genus, though closely related to those which immediately follow it, finds its nearest allies in the Melosiree, whose genera, from their filamentous character, stand widely apart in the present work.
BRITISH DIATOMACEA. 93
Were the frustules of Coscinodiscus eccentricus, for example, perma- nently coherent after self-division, it would be difficult to separate them in a generic point of view from those of Orthosira nivalis, W. Sm., which have the same cellular structure of the siliceous valve, or from those of Melosira aurichalcea, Ralfs, or Orthosira sulcata, Kiitz., which are furnished with a projecting fringe of silex, the homologues of the spinous processes in C. eccentricus. It is true that the Melosiree 1 have mentioned have valves much more convex, occasionally even cylindrical ; but in Orthosira arenaria, W. Sm., this difference disappears, and we have frustules as much compressed and in consequence as narrow on the F. V. as in Coscinodiscus, and differing principally in the firm and permanent coherence of their surfaces.
1. Coscinodiscus minor, Hir. Cells of V. circular, margin smooth.
V.S.
Ehr. in Kiitz. Bacill. i. 12? Fresh water. Aberdeenshire, Dr. Dickie. Plate III. 36.
2. Coscinodiscus radiatus, Ehr. Cells distinctly hexagonal, ar- ranged concentrically, largest in the centre of valve, margin smooth. Diameter :0018" to 0055". v.v.
Kutz. Bacill. i. 18. Prit. Anim. xiv. 39.
Marine. Poole Bay, 1848. Stomach of Scallop, coast of Sussex, W. Sm. Coast of Norfolk, Mr. Brightwell. Near Folkestone, Mr. Capron. (Peruvian and African Guano.)
Plate III. 37.
3. Coscinodiscus eccentricus, Hhr. Cells arranged in eccentric lines, margin spinous. Diameter :0006" to 0038". v.v. Kitz. Bacill. i. 9.
Marine or brackish water. Poole Bay, Aug. 1848. Near Lewes, July 1850. Stomach of Scallop in great numbers, Feb. 1851.
Plate III. 38.
24 BRITISH DIATOMACE.
Genus 7. EUPODISCUS, Ear.
Frustules free or adherent, disciform; valves convex; disc with elevated processes.
Closely allied to the last, but differing from it in the less distinctly cellular structure of the valve, which in some species is wholly absent, and in the presence of the horn-like processes of the disc, which do not occur in Coscinodiscus. It differs from Genus 10. in its orbicular form and in the horns springing directly from the surface of the valve, while in Triceratium they are confined to the anyles and are formed by the prolongation of the latter.
1, Eupodiscus Argus, Hhr. Cells of V. irregular in outline, pro- cesses three or four. Diam. *0065" to 0113". v.s.
Kitz. Bacill. i. 6. £. Germanicus, Kiitz. Sp. Alg. p. 134. Prit. Anim.
xahy, Zul
Marine or brackish water. Thames near Gravesend, Mr. Poulton. Near Faversham, Mr. Shadbolt. River Orwell near Ipswich, Mr. Hodgson.
Plate IV. 39.
2. Eupodiscus fulvus, n.sp. Cellular structure indistinct, radiate ; colour of dry valve tawny. Diam. 0018" to 0028". v.v. Marine. Poole Bay, Sept. 1851, W. Sm. Plate IV. 40.
3. Eupodiscus crassus, n.sp. Cells circular; V. somewhat opaque ; colour of dry V. purplish; margin smooth. Diam. ‘0011 to -0021. V.Ve
Marine. Poole Bay, 1848, W. Sm. Near Ipswich, Mr. Hodgson. Plate IV. 41.
4, Eupodiscus radiatus, Bai/.? Cellular structure of V. distinct; cells circular; processes four, radiate, two larger than the others. V.S.
Marine. Detected by Mr. West among other Diatomacez from the rivers Orwell and Thames.
Supp. Plate XXX. 255.
BRITISH DIATOMACE. 95
5. Eupodiscus sculptus, n.sp. V. striated, the central striae form- ing a quatrefoil; processes two. Diam. 0013" to ‘0025". v.s.
Marine. Poole Bay, Sept. 1851, W. Sm. Plate IV. 42.
Genus 8. ACTINOCYCLUS, Fir.
Frustules free or adherent, disciform; valves cellular, undulated ; pseudo-nodule central, conspicuous.
The undulations on the surface of the valves appear on the side view as radiating bands; on the front view their true character is easily seen, and they at once distinguish this genus from its allies. It may also be noticed that the cellular structure of the disc is absent from a small portion (pseudo-nodule) in the centre of the valve.
1. Actinocyclus undulatus, Kiitz. Valve with six rays. Diam. "0009" to :0040". v.v.
Kitz. Bacill. 1. 24.
Marine or brackish water: frequent. Poole Bay, Sept. 1849. Near Lewes, Sept. 1850, W. Sm. Near Ipswich, Mr. Hodgson. (Peruvian Guano; Rich- mond, Virginia.)
Plate V. 43.
Genus 9. ARACHNOIDISCUS, Bail.
Frustules adherent, disciform; valves plane or slightly convex, cel- lular, marked with concentric and radiating lines; pseudo-nodule central, conspicuous.
This beautiful genus was, I believe, established by Professor Bailey of New York, and has been found in abundance upon Algz collected in Japan, California and South Africa. The discovery of its British habitat is due to M. De Brébisson of Falaise, who detected a single frustule of the species described below on Sphacelaria olivacea, Ag., collected by Mr. Ralfs at Ilfracombe in North Devon. A minute description of this species with carefully executed figures has been
26 BRITISH DIATOMACEZ.
given by Mr. Shadbolt in the Transactions of the Microscopical Society of London, vol. iii. p. 49.
1. Arachnoidiscus Ehrenbergii, Baij]. Pseudo-nodule surrounded with a double row of puncta, the interior linear, the exterior cir- cular. Diam. ‘0051" to 0161". v.s.
A. Ehrenbergii, Bail. sic cl. De Brébisson in lit. cum icone photographica pulcherrima! 4. Japonicus, Prit. Anim. xxiv. 18-21.
Marine. Ilfracombe, Mr. Ralfs. Supp. Plate XXXI. 256.
Genus 10. TRICERATIUM, Fir.
Frustules free or attached, triangular; valves cellular, angles elevated or produced.
The triangular form of the frustules separates this genus from all its allies, from which it is also distinguished by the absence of a pseudo-nodule, the appearance of such in 7. striolatum? being pro- bably accidental in the single individual from which the figure was drawn. ‘The frustules are probably at first attached to larger Algze, but I have been unable to determine this point from the isolated spe- cimens which have fallen under my notice. The species hitherto found in Britain have occurred on the southern and eastern coasts, in the mud of tidal rivers.
1. Triceratium Favus, Hhr. Cells hexagonal, angles produced into horn-like obtuse processes. v.s.
Kiitz. Bacill. xviii. 11. Quek. H. C. xii. 22a. Bail. Sound. fig. 54. Prit. Anim. xiv. 43, 44.
Marine or brackish water. Thames near Faversham, Mr. Shadbolt. River Orwell near Ipswich, Mr. Hodgson. (Near Charlestown, communicated by Prof. Williamson.)
Plate V. 44. Supp. Plate XXX. 44. 2. Triceratium alternans, Bail. Cells circular, angles slightly elevated. v.s.
Bail. Sound. figs. 55, 56.
BRITISH DIATOMACE, oO
Marine. Poole Bay, Aug. 1848. Hove, Sussex, Nov. 1852, very sparingly, W. Sm. Folkestone, Sept. 1852, Mr. Capron. (Peruvian Guano.)
Plate V. 45. Supp. Plate XXX. 45.
3. Triceratium striolatum ? Ehr. V. with acute angles, not ele- vated or produced; cellular structure faintly discernible. v.s.
Kitz. Bacill. xviii. 10?
Brackish water. Near Lewes, Oct. 1850, W. Sm. I refer this doubtfully to the species described and figured by Prof. Kutzing.
Plate V. 46.
Genus 11. CYCLOTELLA, Kitz.
Frustules free or adherent, disciform ; valves convex or plane, striated, striz rayed.
Closely allied to Coscinodiscus and Melosira, the absence of a cel- lular structure separating it from the first, the shallow valve and non- adherent frustule from the second. The undulations on the F.V. of the species first described, which are by no means constant, are probably due to an irregular depression in the centre of the valve, a character which may be also noticed in the second species, but being less strongly marked in the latter, and the outline being more regular, the appearance of undulations is not so evident. I have also noticed in the first species, that although no undulations may be discernible in the dry frustule, they become apparent when the objects are im- mersed in balsam.
1. Cyclotella Kiitzingiana, Thw. V. undulated; striz delicate, extending over half the disc, at margin 20 in 001"; centre of V. smooth. Diam. :0005" to 0015". v.v.
§. Valve without undulations.
Thw. Ann. 2nd Ser. vol. i. pl. xi. p. C. operculata (. rectangula, Kitz. Sp. Alg. p. 19. ad specimina que misit cl. De Brébisson, Oct. 1852.
Fresh or brackish water. Near Bristol, Mr. Thwaites. Wareham, Nov. 1848. (3. Lewes, Oct. 1850, W. Sm. Thames, Northfleet, Mr. Shadbolt, Feb. 1851.
Plate V.47. 4', Sporangial (?) frustule. Frustule with endochrome, Fron- tispiece, fig. XLVIT.
28 BRITISH DIATOMACE.
2. Cyclotella operculata, Kiitz. V. depressed in centre; striz obscure, very short, 36 in 001". Diam. :0005" to 0012". v.v. Ag. Consp. p. 11. Kiitz. Bacill. i. 1.
Fresh water. Plumpton, Sussex, Mar. 1852, W. Sm. Lough Neagh, Dr. Dickie. Cantyre Peat, &c.
Plate V. 48.
3. Cyclotella antiqua, n.sp. V. convex; striz broad, not reaching the margin. Diam. -0009" to :0013". v.s.
Fresh water. Lough Mourne and Peterhead Deposits. Cantyre Peat, and Marl, Co. Down.
Plate V. 49.
4, Cyclotella Rotula, Kitz. V. plane; striz numerous, distinct, 14n-001". Diam. -0015" to -0022". y.s.
Kitz. Bacill. ii. 4. Discoplea atmospherica, Ehr. in Prit. Anim. xxiv. 1 & 2? Fresh water. Lough Neagh, Dr. Dickie. Plate V. 50.
Genus 12. CAMPYLODISCUS, Ljhr.
Frustules free, saddle-shaped ; valves equidistant ; canaliculi radiated.
The species included under this genus may all be recognised by the characteristic bend or contortion of their surfaces. The cost, as in Epithemia, appear to arise from the presence of minute canals which form means of communication between the internal cell-mem- brane and the surrounding fluid. In one species, C. cribrosus, these appearances are absent; but the presence of foramina on the margin in this species seems to indicate the existence of canaliculi, though
these are not apparent as distinct costae.
1. Campylodiscus Horologium, /Vi//. V. circular; canaliculi about 50, in length one-third of the radius; centre of V. smooth. Diam. *0051" to -0068". v.s.
Prof. Williamson in Ann. Nat. Hist. May 1848.
Marine. Coast of Skye, dredged in 60 fathoms water by Mr. G. Barlee, communicated by Prof. Williamson.
Plate VI. 51.
BRITISH DIATOMACE. 29
2. Campylodiscus costatus, JV. Sm. V. circular; canaliculi from 30 to 40, in length about half of the radius; centre of V. minutely punctate. Diam. 0025" to 0050". v.v.
Var. 3. V. somewhat elliptical, disc distinctly punctate. W. Sm. Ann. 2nd Ser. vol. vii. pl. i. 1. Bright. Inf. pl. ix. 10.
Fresh water. River Frome near Dorchester, May 1849. Near Lewes, Aug. 1850, W. Sm. Bramley Spring near Guildford, Mr. Capron. Norfolk, Mr. Brightwell. Lough Mourne Deposit. Peterhead Deposit. Dolgelly Earth, &c. &e. Var. 3. Cantyre Peat.
Plate VI. 52. \Var. 6. Pl. VII. 52.
3. Campylodiscus Hodgsonii, n. sp. V. nearly circular; canaliculi very numerous, 100 or upwards, in length about one-third of the radius ; centre of the disc cellular ; cells circular, in radiating lines. Diam. *0018" to :0052". ws.
Marine. Near Ipswich, Mr. Hodgson, July 1851. Poole Bay, Oct. 1851, W. Sm.
This beautiful species varies much in size, but presents throughout its cha- racteristic features. The disc is frequently traversed by a smooth line cor- responding with its longest diameter: a F. V. shows us that this line is formed by a ridge and two contiguous furrows passing across the valve. It is worthy of remark that the ridges on the two valves of the same frustule are not uniformly opposite, but cross each other at various angles: a similar circum- stance may sometimes be noted in Hupodiscus and other disciform frustules.
Plate VI. 63: 5°?
4, Campylodiscus spiralis, V7. Sm. FF. twisted so as to present a spiral outline; V.elliptical; canaliculi about 60, nearly parallel; centre of the disc minutely punctate. Longest diam. :0042" to 0083". v.v.
W. Sm. Ann. 2nd Ser. vol. vii. pl.i. 2. Surirella spiralis, Kitz. Bacill. ii. 64?
Fresh water. Bramley near Guildford, Oct. 1848, Mr. Capron. Lanshaw Spa, near Katefield, Lancashire, Jan. 1852, Mr. Geo. Smith. Norfolk, Mr. Brightwell.
Plate VII. 54. Frustule with endochrome, Frontispiece, fig. LIV.
5, Campylodiscus cribrosus, W.Sm. V. nearly circular ; disc cel- lular ; cells irregularly circular, in radiating lines. Diam. 0041" to
“0052" v.v.
30 BRITISH DIATOMACE.
W. Sm. 2nd Ser. vol. vii. pl. i. 3. C. Argus, Bail. Obs. pl. 1. 24. 25. ad specimina que communicavit Prof. Williamson, Jan. 1852.
Marine or brackish water. Poole Bay, Nov. 1848. Lewes, 1850, W. Sm. Coast of Norfolk, Mr. Brightwell. (Hudson River.)
Plate VIL. 55.
6. Campylodiscus parvulus, WV. Sm. Valves circular; canaliculi about 12, minute, in length about two-thirds of radius. Diam. ‘0011" to °0019". v.v.
W. Sm. Ann. 2nd Ser. vol. vii. pl. i. 4. Prit. Anim. xxiv. 22, 23. Poole Bay, 1848, W. Sm. Plate VI. 56.
7. Campylodiscus Ralfsii, n. sp. V. nearly circular, canaliculi reaching to the median line. Diam. ‘0016" to 0019". vs.
Marine. Ilfracombe, Mr. Ralfs. Supp. Plate XXX. 257.
Genus 13. SURIRELLA, Turp.
Frustules free, ovate or elliptical ; valves with a longitudinal central line, and margins produced into alz; canaliculi distinct, usually parallel.
The only genus with which the present stands in near alliance is Try blionella, from which it is well distmguished by the prominency of its ale, the distinctness of its canaliculi, and the usual cuneate form of its frustules: with no other is it at all likely to be confounded. The surface of the valve in Swriredla, as in the other Diatomacee, is marked with transverse lines ; these are usually very faint in the present genus, but in a few cases they are somewhat conspicuous and have been noted in the specific descriptions.
1. Surirella biseriata, De Bréb. F.V. linear, oblong; V. elliptical- lanceolate; alze conspicuous; canaliculi large, 4 to 6 in O01", usually reaching to central line. Length :0025" to 0083". v.y.
BRITISH DIATOMACE. 31
De Breb. Alg. Falaise, 1835, p. 53. pl. vii. ad spec. authen. que communi- cavit cl. auctor. Hass. Alg. cii. 1. W. Sm. Ann. 2nd Ser. vol. vii. pl. ii. 1. Prit. Anim. xvii. 20-26. Jen. Flo. Tun. p. 204. Nav. bi- Jrons, Ehr. Inf. xiv. 2. Surirella bifrons, Kiitz. Bacill. vii. 10.
Fresh water. Boggy pools frequent, elsewhere occasionally. Wareham, Dec. 1849 ; Lewes, Sept. 1851, W. Sm. Ashdown Forest, Sussex, Mr. Jenner. Lough Mourne and Lough Island-Reavey Deposits, and Premnay Peat.
Plate VIII. 57. Frustule with endochrome, Frontispiece, fig. LVII.
2. Surirella linearis, n.sp. V. linear, occasionally constricted, obtuse or acuminate. v.v.
With the last, and probably varieties of it and S. splendida. Curwen Hill Lot near Lancaster, Mr. Geo. Smith, 1851. Snow Mud, Ben M* Dhui, Dr. Dickie. Cantyre Peat, Xe.
Plate VIII. 58.
3. Surirella constricta, W.Sm. F. V. linear, oblong; V. elliptical, acute, usually with a central constriction ; alae conspicuous; cana- liculi delicate, 10 to 12 in ‘001", reaching to central line, which is often inflated. Length :0028” to -0055". v.v.
W. Sm. Ann. 2nd Ser. vol. vii. p. 9.
Brackish water. Near Lewes, Dec. 1850. Poole Bay, Sept. 1851. Lancing, Sussex, Nov. 1852, W. Sm.
Plate VIII. 59.
4, Surirella turgida, n.sp. V. much inflated, irregular in outline, occasionally somewhat constricted towards the obtuse extremities ; canaliculi few, conspicuous, 4 in ‘001". Length :0033" to 0052". V.S.
Fresh water. Lough Neagh, Dr. Dickie, 1850. Plate [X. 60.
5. Surirella lata, n. sp. V. elliptical, with rounded ends and frequently with a central constriction ; canaliculi conspicuous, 3 or 4in‘001"; margin striated; striz 36 in 001". Length -0041" to 0062". v.s.
Marine. Coast of Skye, Prof. Williamson. Ilfracombe, Mr. Ralfs. Plate IX. 61.
3 BRITISH DIATOMACE.
6. Surirella splendida, Kiitz. F.V. ovate; V. ovate, elongated, ale distinct ; canaliculi conspicuous, 4 in :001", reaching the central line. Length ‘0050" to :0072". v.v.
Kiitz. Bacill. vii. 9. ad specim. authen. quee misit amic. De Brébisson. W.
Sm. Ann. 2nd Ser. vol. vii. pl. ii. 2. Nav. splendida, Ehr. Inf. xiv. 1. Prit. Anim. i. 151.
Fresh water. Near Lewes, Oct. 1850. Ashdown Forest, Sept. 1851, WV. Sm. Premnay and Cantyre Peat. Dolgelly Earth.
Plate VIII. 62.
7. Surirella nobilis, n.sp. V. linear-ovate ; canaliculi conspicuous, 3 in ‘001", not reaching to the central line. Length -0083" to *O144!5y.s:
Surirella splendida, W. Sm. Ann. 2nd Ser. vol. vii. pl. ii. 3.
Fresh water. Lough Mourne Deposit. Dolgelly Earth. Raasay Earth. Lough Island-Reavey Deposit, &c.
Plate VIII. 63.
8. Surirella striatula, Turp. VV. broadly ovate, faintly striated ; strie 40 in 001"; canaliculi distant, 3 in 001", reaching the central line. Length :0041” to 0061". v.v.
Kitz. Bacill. vii. 6. W. Sm. Ann. 2nd Ser. vol. vii. pl. ti. 1. MNavicula striatula, Ehr. Inf. xxi. 15. Prit. Anim. in. 137. Bright. Inf. ix. 2.
Marine or brackish water: common. Poole Bay, July 1848. Newhaven, Sussex, Feb. 1852, W. Sm. Coast of Norfolk, Mr. Brightwell.
Plate IX. 64. Frustule with endochrome, Frontispiece, fig. LXIV.
9. Surirella Gemma, Hir. F. V. ovate; V. ovate or elliptical ; alee distinct; canaliculi delicate, unequally distant, reaching central line; surface of V. striated; striz 48 in -001". Length :0025" to 0058". v.v.
Kitz. Bacill. vi. 11. W. Sm. Ann. 2nd Ser. vol. vii. pl. i. 2. Prit. Anim.
xOYo My Oh Zhe Marine: common. Poole Bay, July 1849. Shoreham Harbour, Aug. 1850, &e., W. Sm.
Plate IX. 65.
10. Surirella fastuosa, Hhr. V. ovate, ale small; canaliculi few, inflated towards the margin; median line turgid. Length 0020" tocQ025", v.v.
BRITISH DIATOMACE. 33
Kiitz. Bacill. xxviii. 19. W. Sm. Ann, 2nd Ser. vol. vii. pl. ii. 3.
Marine. Poole Bay, Sept. 1848; Pevensey Bay, Oct. 1850, W. Sm. (Peruvian Guano.)
Plate IX. 66.
11. Surirella Craticula, Hhr. V. lanceolate; alee distinct; cana- liculi few, small, divergent, reaching the median line. _ v.s.
Kiitz. Bacill. xxviii. 22, W. Sm. Ann. 2nd Ser. vol. vii. pl. iti. 4. Prit. Anim. xv. 19-20.
Fresh water. Bramley Spring near Guildford, Mr. Capron. River Bann, Mr. Cocken. Lough Mourne Deposit.
Plate IX. 67.
12. Surirella ovalis, Bréb. V. ovate, acuminate, striated ; striz 36 in 001"; ale inconspicuous; canaliculi marginal, numerous, 12 in 001", Length :0021" to :0038". v.v.
Kiitz. Bacill. xxx. 64. W. Sm. Ann. 2nd Ser. vol. vii. pl. ii. 7.
Fresh water. Near Lewes, Dec. 1852, VW. Sm. Near Bristo), Mr. Thwaites. Norfolk, Mr. Brightwell. Pilling, Lancashire, Rev. J. Bannister.
Plate IX. 68.
13. Surirella panduriformis, n.sp. V. with a subcentral constric- tion; extremities rounded; canaliculi inconspicuous. Length 0009" to :0016". v.v.
Fresh water. Iford near Lewes, Oct. 1852, W. Sm. Supp. Plate XXX. 258.
14. Surirella Brightwellii, JV. Sm. V. orbicular, with one extremity acute, striated; striae 32 in °001"; al inconspicuous; canaliculi distinct, marginal, 10 in 001". Length 0011" to ‘0016". v.v.
Surirella Crumena, Bréb. in Kitz. Sp. Alg. p. 38. sic cl. De Brébisson in lit. cum specim., Sept. 1852.
Fresh or brackish water. Coast of Norfolk, Mr. Brightwell, 1850. Lewes, Sept. 1851, W. Sm.
Plate IX. 69.
15. Surirella ovata, Kiitz. V. ovate, minute; ale small; canali- culi marginal, 11 in 001". Length 0008" to 0018". v.v.
Kutz. Bacill. vu. 1, 2, 3.
34 BRITISH DIATOMACES.
Fresh or brackish water. Lewes, March 1851, VW. Sm. Northfleet, Kent, Mr. Shadbolt, Feb. 1852.
Plate IX. 70.
16. Surirella salina, WV. Sm. V. ovate-elliptical; ala obsolete ; canaliculi minute, marginal, numerous, 14 in 001". Length 0005" to 0018". v.v.
W. Sm. Ann. 2nd Ser. vol. vii. pl. i. 6.
Marine or brackish water. Poole Bay, Sept. 1847; Hastings, Aug. 1851, W.Sm. Timber Pond, W. I. Docks, Feb. 1852, Mr. Shadbolt.
Plate IX. 71.
17. Surirella pinnata, n.sp. V. linear-ovate; alze obsolete ; cana- liculi large, subdistant, marginal, 15 in ‘001". Length :0006" to 0013". v.v.
Fresh water. Near Lewes, Jan. and Dec. 1852, W. Sn.
PBlates Xu 2.
18. Surirella angusta, Kiitz. F. V. linear truncate; V. linear, acu- minate; ala obsolete; canaliculi 18 in ‘001". Length -0008" to 0014 Waves
Kiitz. Bacill. xxx. 52. ad specim. que misit amic. De Brébisson, Jan. 1853. Fresh water. Lewes, Dec. 1852, W. Sin.
Supp. Plate XXXI. 260.
19. Surirella subsalsa, n.sp. F.V. oblong, inflated; V. elliptical- ovate, striated; striz 30 in :001"; larger extremity rounded, rarely attenuated; alae conspicuous ; canaliculi distinct, 8 in ‘001". Length 0006" to -0016". v.v.
Fresh or brackish water. ‘* Brooks” near Lewes, Oct. 1852; Newhaven, Sussex, Dec. 1852, W. Sm.
Supp. Plate XXXI. 259.
20. Surirella minuta, De Bréb. V. ovate-elliptical; ale incon- spicuous; canaliculi marginal, 14 in -001". Length 0005" to 0009". v.v.
De Brébisson in Kiitz. Sp. Alg. p. 38. ad specimina authentica quae commu- nicavit cl. Jenner. W. Sm. Ann. 2nd Ser. vol. vii. pl. ii. 5.
Fresh water. Corfe Castle, Dec. 1849 ; Lewes, March 1851, W. Sm. Plate IX. 73.
BRITISH DIATOMACEA, 35
Genus 14. TRYBLIONELLA, IV. Sm.
Frustules free, elliptical or linear; valves plane; ale submarginal or obsolete ; canaliculi inconspicuous, parallel.
This genus differs from Campylodiscus in the more elongated form of its frustules and the absence of the characteristic bend in its valves; the canaliculi are also more minute and parallel rather than radiating. It agrees with Swriredla in the presence of ala, but these arise from the disc, and are not, as in Surirella, prolongations of the margin. It is also distinguished by its less conspicuous canaliculi, and by the frustule never assuming the cuneate form so notable in Surirella.
1. Tryblionella Scutellum, n.sp. V. elliptical, marked with a cen- tral depressed line; canaliculi obsolete ; ala very short. Length 50058!) to, 0085". v.v.
Surirella circumsuta, Bail. Obs. pl. 1. 36. ad specimina quee communicavit Prof. Williamson.
Marine. Poole Bay, Nov. 1848, W. Sm. (Hudson River.) Plate X. 74.
2. Tryblionella gracilis, n.sp. IF. V. linear, attenuate towards the extremities ; V. linear acuminate; canaliculi parallel, extending to the central line, 10 to 12 in 001"; ale distinct. Length -0023" to 0075". v.v.
Fresh and brackish water. Near Lewes, Dec. 1850, and Oct. 1852, W. Sin. Plate X. 75. Frustule with endochrome, Frontispiece, fig. LXXV.
3. Tryblionella marginata, n.sp. F. V. inflated, extremities ob- tuse; V. elliptical, acuminate; canaliculi distinct, marginal, 18 in 001"; alz conspicuous. Length :0011" to 0026". v.v.
Fresh and brackish water. Near Lewes, Sept. 1851, W.Sm. Pilling and
Cockerham Marshes, Lancashire, M7. Johnson. Near Belfast, Dr. Dickie. Plate X. 76. Ideal section of frustule, Pl. X. fig. s.
D 2
36 BRITISH DIATOMACE.E.
4, Tryblionella punctata, n.sp. V. elliptical, acuminate, striated ; striz moniliform, 31 in -001"; canaliculi obsolete. Length 0012" to <O021". wiv.
Marine. Coast of Sussex, sparingly, Sept. 1850, W. Sm. Plate X. 76. a’. Supp. Plate XXX. 261.
5. Tryblionella acuminata, n. sp. V. linear, acuminate; canaliculi obscure ; striz delicate, 40 in ‘001", interrupted; ale obsolete. Length :0025" to :0042". v.s.
Marine and brackish water. Poole Bay, June 1849; Belfast Bay, Sept. 1849; near Lewes, Dec. 1850, WV. Sm.
Plate X. 77.
6. Tryblionella angustata, n.sp. V. as in the last species; striz continuous, 36 in ‘001". Length :0021” to -0040". v.v. Fresh water. Iford, Sussex, Oct. 1852, W. Sm. Guildford, M7. Capron. Supp. Plate XXX. 262.
Genus 15. CYMATOPLEURA, I’. Sm. Frustule free, oblong, or elliptical; valves undulated.
The undulations of the surface of the valves separate the present genus from both the last ; the absence of alee and canaliculi are further characters which leave no room for hesitation as to its distinctness.
1, Cymatopleura Solea, /V. Sm. F. V. oblong, linear; V. fiddle- shaped, symmetrically divided by a central sinus on each margin ; undulations six ; surface of V. striated ; strize 18 in ‘001". Length "0042" to 0115". v.v.
W. Sm. Ann. 2nd Ser. vol. vii. pli. 9. Navicula librilis, Ehr. Inf. xii. 22. Prit. Anim. xvii. 9. Surirella Solea, Kitz. Bacill. iii. 61. Sphincto- cystis librilis, Hass. Alg. ci. 3.
Fresh water: common. Lewes, May 1850, and Oct. 1852, &e., W. Sin.
Plate X. 78. Frustule with endochrome, Frontispiece, fig. LX XVIII.
BRITISH DIATOMACE. 37
2. Cymatopleura apiculata, n.sp. V. fiddle-shaped, apiculated ; undulations about four. Length 0021" to -0051". v.v.
C. Solea, W. Sm. Ann. 2nd Ser. vol. vii. pl. ii. 8.
In numerous localities with the former. I am not certain that the present is entitled to rank as a distinct species ; it is usually much smaller than the former and of a more rounded outline, but intermediate specimens sometimes occur, and in Ehr. Inf. xin. 22. fig. 2, copied in Prit. Anim. pl. iii. fig. 155, we have a form as large as Solea with distinct apicula as in the present species.
Plate X. 79.
3. Cymatopleura parallela, n. sp. V. linear, extremities attenuate, obtuse. Length :0021" to :0048".
Fresh water. Iford near Lewes, Oct. 1852, W. Sm.
Supp. Plate XXX. 263.
4, Cymatopleura elliptica, JV. Sm. V. broadly elliptical, some- what acuminate, with four or five undulations ; surface obscurely striated. Length :0016" to 0055". v.v.
Surirella elliptica, Bréb. in Kiitz. Spec. Alg. p. 37. ad specimina que com-
municavit cl. De Brébisson, Aug. 1852. W. Sm. Ann. 2nd Ser. vol. vi. pli LOéall Prits Anim: xvi, 7,
Fresh water: frequent. River Frome, May 1849. Plumpton, Sussex, April 1852. Guildford, Mr. Capron, &e. &c. The larger variety in Lough Mourne and Peterhead Deposits, Dolgelly Earth, &c.
Plate X. 80.
5. Cymatopleura Hibernica, !V.Sm. V. orbicular, with prominent subacute extremities; undulations three; striz obscure. Length 50022) tor- 0052". vas
W. Sm. Ann. 2nd Ser. vol. vi. pl. mi. 12.
Fresh water. Lough Neagh, Co. Antrim, Dr. Dickie. River Bann, Mr. Cocken.
Plate X. 81.
Genus 16. NITZSCHIA, Hass.
Frustules free, elongated, compressed ; valves linear, keeled, with one or more longitudinal lines of puncta; keel frequently eccentric.
This genus embraces a large number of species, differing in form
38 BRITISH DIATOMACEX.
and size, but all agreeing in a few general characters. The most important of these is the keeled form of the valves, and the remark- able inequality, in many of the species, between the portions of the valve lying on either side of this prominency. This inequality, or, in other words, this eccentricity of the keel distinguishes Nitzschia from Amphiprora, in which the keel is also present, while the presence of a keel and its accompanying line or lines of puncta, together with the absence of any form of stipes, separate the present from the genus Synedra, with which several of its species have been united by pre- vious authors. The true character of the valve may be detected by a careful examination of the desiccated frustule, and is easily seen in the figures given in Plates XIII. and XIV. The fractured valve shown in Pl. XIV. fig. 118. a, and the sections given in figs. 115. 8. and 118.8. will more particularly serve to illustrate the form of valve peculiar to the genus.
Seer. I. Frustules sigmoid. (Sigmatella, Kiitz.)
1. Nitzschia sigmoidea, JV. Sm. F. linear, sigmoid, truncated ; V. linear, suddenly tapering towards the acute extremities; keel with a single line of puncta; striz 85 in ‘001". Length -0116” to “O192! Vive B. F. reflexed ; strize distinct, 42 in ‘001".
Navicula sigmoidea, Ebr. Inf. xin. 15. Synedra sigmoidea, Kutz. Bacill. iv. 37. Niteschia elongata, Hass. Alg. cn. 12. Sigmatella Nitzschii, Kitz. Sp. Alg. p. 18.
Fresh water: very common. Lewes, Dec. 1851, W. Sm. (. Lough Mourne Deposit. Dolgelly Earth.
Plate XIII. 104. 104. F. V. of single valve of var. 6. Frustule with endochrome, Frontispiece, fig. CIV.
2, Nitzschia Brebissonii, JV. Sm. F. broader and less sigmoid than the last on the F.V.; V. linear; extremities attenuate, pro- duced, obtuse; striae 27 in :001"”. Length 0034" to 0092". v.v.
Synedra Armoricana, Kitz. Bacill. iv. 34. Sigmatella Brebissonii, Kiitz. Sp. Alg. p. 18. ad specimina quee misit cl. De Brébisson, Oct. 1852.
Fresh water. Near Lewes, Oct. and Dec. 1852, W. Sm.
Supp. Plate XXXI. 266.
BRITISH DIATOMACE. 39
3. Nitzschia Sigma, JV. Sm. F.on F. V. linear, gradually tapering towards the truncated extremities ; V. linear on F. V., somewhat lanceolate, acute; stria 56 in ‘001’; puncta of keel in a double row. Length :0050" to 0116". v.v.
Synedra Sigma, Kutz. Bacill. xxx. 14. Marine or brackish water. Pevensey Bay, Sept. 1850, W. Sm. Plate XIII. 108.
4, Nitzschia obtusa, n. sp. F. on F. V. linear, with rounded ex- tremities; V. linear, obtuse; puncta double; striae 56 in -001". Length :0042" to 0121". v.v.
Brackish water. Shagalieu Marsh, Poole Bay, June 1849, W. Sm. Plate XIII. 109.
5. Nitzschia spectabilis, n.sp. F. on F. V. linear, sigmoid, trun- cate; keel nearly central; puncta in 4 rows, the more distant on each side larger; V. striated. v.s.
Brackish water. Near Ipswich, Mr. Hodgson, Aug. 1851. Plate XIV. 116.
Sect. II. Valves linear, straight.
6. Nitzschia scalaris, /V. Sm. F. V. linear, inflated towards the truncated extremities ; V. linear, slightly tapering towards the ex- tremities, which are somewhat acute; keel eccentric; puncta double, alternately produced into shorter and longer striz ; surface of valve distinctly striated; strice 24 in ‘001". Length °0125" to OL 7O. viv.
Synedra scalaris, Kutz. Bacill. xxvii. 32. Brackish water. Shagalieu Marsh, Poole Bay, June 1849, WV. Sm. Plate XIV. 115. Ideal section of frustule, fig. 115 s.
7. Nitzschia linearis, VY. Sm. F.V. linear, with rounded or trun- cated extremities, occasionally with a slight central constriction ; V. linear, with acuminate extremities; keel nearly central; puncta in a single row; striz obscure. Length :0023” to 0075".
Frustulia linearis, Ag. ex sp. authen. quee misit cl. Dr. Greville.
40 BRITISH DIATOMACE. Surirella multifasciata, Kutz. Bacill. ii. 47. et Synedra oxyrhynchus, Kitz. Sp. Alg. p. 44. ad specimina que misit cl. De Brébisson, Sept. 1852.
Fresh water: common. Lewes, March 1852, W. Sm. Wray, Mr. G. Smith, Noy. 1852. (Ceylon, Mr. Thwaites, Nov. 1850.)
Plate XIII. 110. Supp. Plate XXXI. 110.
8. Nitzschia tenuis, /V. Sm. F. V. linear, occasionally slightly sigmoid, extremities truncate; V. narrow, lanceolate, acute; striz obscure. Length :0042" to :0083". v.v.
Synedra tergestina, Kutz. Bacill. iv. 33. ad specimina quee communicayit cl. De Brébisson, Oct. 1852.
Fresh water. Near Lewes, March 1850, W. Sm. Wray near Lancaster, Mr. G. Smith.
Plate XIII. 111.
Sect. III. Valves lanceolate.
9. Nitzschia spathulata, n. sp. F. V. linear-lanceolate, extremities inflated; V. lanceolate, acute, with a single row of puncta. Length 0041" to :0083". vs.
“ Nitzschia spathulata,’ cl. De Brébisson inliteris cum speciminibus, Sept.1852.
Marine. Hull, Mr. R. Harrison. Supp. Plate XXXI. 268.
10. Nitzschia angularis, n.sp._ F. V. lanceolate, truncate; V. lan- ceolate ; keel central; puncta in a single row; surface of V. longi- tudinally striated. Length :0041" to :0065". v.v.
Marine. Coast of Sussex, July 1850, W. Sm. Plate XIII. 117.
11. Nitzschia lanceolata, WV. Sm. F. V. lanceolate, extremities acute; V. linear lanceolate, acute; keel eccentric; surface of valve marked by longitudinal lines, 21 in ‘001"; striz faint, 80 in -061". Length :0048” to :0085"._ v.y.
Surirella curvula, Bréb. in Kitz. Sp. Alg. p. 36. ad specimima quae commu-
nicavit cl. De Brébisson, Sept. 1852. Marine. Pevensey Bay, Sussex, Nov. 1850, W. Sin.
Plate XIV. 118. Ideal section of frustule undergoing self-division, fig. 118.8.
BRITISH DIATOMACE.®. 41
Sect. IV. Valves arcuate.
12. Nitzschia Amphioxys, V7. Sm. F. V. linear, quadrangular ; V. elliptical-lanceolate, arcuate, with acute and somewhat promi- nent extremities; striz distinct, 30 in :001". Length -0016" to "0043", v.v.
Eunotia amphiowys, Kitz. Bacill. xxix. 44, xxx. 1.
Fresh water: common. Lewes, Jan. 1851, W. Sin.
Plate XIII. 1035.
13. Nitzschia vivax, n.sp. FI. V. linear; V. linear-lanceolate, ar- cuate, extremities produced into a prominent beak; striz distinct, 30 in 001". Length 0026" to 0056". v.v.
Fresh or slightly brackish water. Near Lewes, Oct. 1852, W. Sin.
Supp. Plate XXXI. 267.
14. Nitzschia parvula, n. sp. V. with central constriction, puncta obscure, extremities prominent; striz faint, 70 in ‘001", Length 0012" to -0015". v.v.
Marine: encrusting a sponge, Poole Bay, Noy. 1849, W. Sm.
Plate XIII. 106.
15. Nitzschia minutissima, /V. Sm. V. linear; puncta distinct, with prominent and acute extremities; striz obscure, 72 in -001". Length -0008" to 0011". v.v.
Synedra dissipata, Kitz. Bacill. xiv. 3. xxx. 53. ad specimina que misit cl. De Brébisson, Sept. 1852.
Fresh water: on chalk rocks. Near Beachey Head, April 1852, W. Sm.
Plate XIII. 107.
Sect. V. Valves constricted.
16. Nitzschia dubia, V7. Sm. F. V. elliptical, slightly constricted towards the centre, and tapering towards the somewhat truncate extremities; keel very eccentric; V. obscurely striated; striz 60 in 001". Length -0042" to 0066". v.v.
. A smaller form.
42 BRITISH DIATOMACE.
{. Synedra constricta, Kutz. Bacill. iii. 70. ad spec. quee dedit amic. De Bré- bisson.
Brackish water. Near Lewes, Oct. 1851, W. Sm. Hull. Mr. Harrison. Coast of Norfolk, Mr. Shadbolt.
Plate XIII. 112. Plate XIV. 112. Var. 8. Supp. Plate XXXI. 112 £.
17. Nitzschia bilobata, V. Sm. F. on F. V. elliptical, with a central constriction, and round or truncate extremities; V. linear-lanceo- late, acute; puncta double; keel central; striz distinct, 56 in 7001". Length -0033” to :0058"._ v.v.
Amphiprora latestriata, Bréb. in Kiitz. Sp. Alg. p. 93. sic cl. De Brébisson
in lit. Aug. 1852. Brackish water. Poole Bay, Oct. 1849. Shoreham, Nov. 1852. Plate XV. 113.
18. Nitzschia plana, n. sp. F. on F. V. elliptical, with a central constriction and acute extremities; V. linear-lanceolate, acute; puncta in a single row; keel eccentric; surface of V. obscurely striated; striz interrupted, 56 in :001”. Length 0058" to 0076". v.v.
Brackish water. Poole Bay, June 1849, W. Sm. Plate XV. 114.
Secr. VI. Valves with extremities produced. (Ceratoneis, Kiitz.)
19. Nitzschia birostrata, V7. Sm. F. V. straight, in central por- tion somewhat lanceolate; extremities produced into extremely long beaks; keel nearly central; puncta in a single row; striz obscure. Length :0128" to -0169". v.s.
Ceratoneis longissima, Kitz. Sp. Alg. p. 891. ad specimina quee communi-
ceavit cl. De Brébisson, Sept. 1852. Marine. Near Walton, Essex, Mr. Topping. Plate XIV. 119.
20. Nitzschia Closterium, 17. Sm. F. V. arcuate; V. faintly stri- ated ; strize 90 in ‘001; otherwise as in the last. _ v.v.
BRITISH DIATOMACE. 43
Ceratoneis Closterium, Kitz. Bacill. iv. 11. Ebr. in Prit. Anim. xv. 99. Marine and brackish water. Hove, Sussex, May 1851, W. Sm. Plate XV. 120.
21. Nitzschia reversa, n.sp. F. V. lanceolate ; extremities produced into beaks which are bent in contrary directions; striz 48 in 001"; puncta obsolete. v.v.
Brackish water. Near Lewes, Nov. 1851, ”. Sm. Plate XV. 121.
99, Nitzschia acicularis, WV”. Sm. F. V. lanceolate, extremities produced, beaks straight; V. faintly striated; striz 98 in -001". V.v.
Synedra acicularis, Kiitz. Bacill. iv. 3.
Fresh water. Near Lewes, May 1852, W. Sm. Plate XV. 122.
23. Witzschia Tenia, JV. Sm. F. V. linear-lanceolate, occasionally sigmoid, extremities produced ; beaks direct or curved; V. striated, striz 72 in ‘001"; endochrome in dry frustule apparently arranged in a spiral manner. _ v.v.
Ceratoneis gracilis, Bréb. in Kutz. Sp. Alg. p. 89. ad specim. quae communi- eavit cl. De Brébisson, Oct. 1852.
Brackish water. Near Lewes, Sept. 1851, 7. Sm. Braunton, Devonshire, Mr. Ralfs, Oct. 1849.
Plate XV. 123.
Genus 17. AMPHIPRORA, Ehr.
Frustules free, elliptical, constricted; valves convex, keeled; keel central, with a longitudinal line, and nodules at centre and ex- tremities.
The very peculiar frustules of this genus cannot be confounded with any others, save with those of the fifth section of the last genus, and from these they are usually distinguished without much difficulty,
44 BRITISH DIATOMACE.
owing to their deeper constriction, the central position of their keel, and their less firmly siliceous structure. They are frequently found in large numbers, and with the exception of one species are marine in their habitat. They are common in the estuaries of all our larger rivers, and the sheltered bays of the southern and western coasts of England. I have also examined specimens from the coast of Nor- mandy, the shores of the United States, and the Arctic Regions.
1. Amphiprora alata, Kiitz. F. twisted; F. V. elliptical, with rounded extremities; V. linear-elliptical; keel accompanied by a double line of puncta; surface of V. striated; striz 42 in :001". Length 0025" to -0052". v.v.
Kiitz. Bacill. ii. 63. Bright. Inf. x. 1.3. Prit. Anim. xvi. 5 & 7. Bail.
Obs. 8, 9, 10.
Marine and brackish water: very common. Coast of Sussex, April and Aug. 1850, W. Sm.
Plate XV. 124. Frustule with endochrome, Frontispiece, fig. CXXIV.
9, Amphiprora paludosa, n.sp. F. twisted; F. V. elliptical, with round or truncate extremities ; constriction very deep; V. striated ; striz 60 in ‘001”. Length -0016” to 0042”. v.v.
In fresh or slightly brackish water. Near Lewes, Sept. 1852, W. Sm. Supp. Plate XXXI. 269.
3, Amphiprora didyma, n.sp. F. straight, elliptical, deeply con- stricted; striz faint, 72 in 001". v.yv. Marine. Lytham, Lancashire, Sept. 1849, W. Sm. Plate XV. 125.
4, Amphiprora vitrea, n.sp. F. straight; F. V. elliptical, con- striction very slight; V. lanceolate, striated ; stria 52 in 001". Length -0023" to ‘0052". v.v.
Marine. Shoreham Harbour, Sept. 1852, W. Sm.
Supp. Plate XX XI. 270.
. Amphiprora constricta, Hhr. I. membranaceous, hyaline Pp p >) b) 5)
straight, elliptical; V. linear-elliptical, with a central sinus and
BRITISH DIATOMACE. 45
transverse line; stria faint, 68 in ‘001", Length 0024" to 0054".
V.V.
Kiitz. Bacill. xxix. 34. Prit. Anim. xvi. 6? Marine and brackish water. Coast of Sussex, April 1850, W. Sm.
Plate XV. 126.
Genus 18. AMPHIPLEURA, Kiitz. Frustules free, linear ; V. with longitudinal ridges.
The structure of the present genus is somewhat obscure. I have not been able to detect the nature of the ridges so conspicuous on the front view, nor to determine the parts of the valve from which they project. Ehrenberg, in his great work Infusionsthierchen, taf. xiii. fig. iii. 7, gives an ideal section of the frustule, which represents the ridges as springing from the surface of a convex valve, having between them a depression which corresponds in position with the ordinary median line of the Navicule. 1am unable to confirm this description, although I have on frequent occasions examined the living and dry valves.
1. Amphipleura pellucida, Kiitz. Frustules linear-lanceolate. Length +0033" to 0054". v.v.
Kiitz. Bacill. iii. 52. Aulacocystis pellucida, Hass. Alg. ci. 8. Nav. pellu- cida, Ehr. Inf. xiii. 3. Prit. Anim. m. 140. KVlee les
Fresh water. Lewes, Nov. 1850, VW. Sm. Katefield, Lancashire, Jan. 1851, Mr. G. Smith.
Plate XV. 127.
2, Amphipleura sigmoidea, /V..Sm. Frustules sigmoid. Length "0058" to °0138". v.v.
Amphipleura rigida, ‘Kitz. Bacill. iv. 30. ad specim. authen. quee communi- cavit cl. De Brébisson.
Marine and brackish water: forms a distinct pellicle or stratum. Bexhill, Sussex, Sept. 1850, W. Sm. Lancing, Noy. 19, 1852.
Plate XV. 128.
46 BRITISH DIATOMACEX.
Genus 19. NAVICULA, Bory.
Frustules free, oblong or lanceolate; valves convex, with a median longitudinal line and nodules at centre and extremities, striated ; striz resolvable into circular dots.
In the present work, the genus Navicula of Kiitzing is divided into three; viz. Navicula, Pinnularia, and Pleurosigma. Stauroneis has already been placed apart both by Ehrenberg and Kiitzing.
The four genera are, I think, sufficiently distinguished from each other ; Navicula, by the delicacy of its strize and their moniliform character ; Pinnularia, by the confluent nature of the cellular structure of its epiderm, which gives to its strize the appearance of distinct ribs or cost; Stauroneis, by the absence of a central nodule, which is supplied by a band of silex (Stauros) crossing the valve at right angles to the median line; and Pleurosigma, by the characteristic curve of its beautiful frustules.
In a few cases we meet with the semblance of a Stauros in the genus Pinnularia; but in these instances a closer examination will show that this appearance arises from the interruption of the cost merely, and not from the dilatation of the central nodule, which is still found unchanged.
Sect. |. Valves lanceolate.
1, Navicula rhomboides, Kir. V.nearly quadrangular; striz very faint, parallel, 85 in :001". Length -0022" to -G037". v.v. Ehr. in Kitz. Bacill. xxvii. 45, xxx. 44, sic Prof. Kitzing in lit. 1851.
Fresh water. Boggy pools, Sept. 1849, W. Sm. Lancashire, Mr. Johnson, Aug. 1851. Ben M° Dhui, at an elevation of 3000 feet, Mr. P. Grant.
Plate XVI. 129.
2. Navicula lanceolata, Kiitz. V. lanceolate or elliptical-lanceolate ; striz parallel, -44 in 001". Length :0012” to -0020". y.v.
Kiitz. Bacill. xxviii. 38. xxx. 48? Fresh water. Newhaven, Sussex, Dec. 1852, W. Sm. Dolgelly Earth.
Supp. Plate XXXI. 272.
BRITISH DIATOMACEA. 47
3. Navicula Crassinervia, Bréb. V. elliptical-lanceolate; extre- mities produced ; striz obscure. Length 0013" to -0026". v.s.
“ Navicula Crassinervia,” ad specimina sub hoc nomine que misit cl. De Brébisson, Sept. 1852.
Fresh water. Wareham, Sept. 1849, 7. Sm. Snow Mud, Grampians, Dr. Dickie. Dolgelly, Mr. Ralfs.
Supp. Plate XXXI. 271.
4. Iavicula serians, Kiitz. V.acute; transverse striz faint, 60 in 001"; longitudinal distinct, 36 in ‘001"; frustules frequently co- hering. Length :0017" to -0035". v.v.
Kutz. Bacill. xxvii. 43, xxx. 23, ad specimina que communicavit cl. De Brébisson in lit. Sept. 1852.
Fresh water: boggy pools. Wareham, Sept. 1849, W..Sm. Forest Row, Sussex, Mr. Jenner, Jan. 1844. Ben M° Dhui, at an elevation of 3000 feet, Mr. P. Grant. Lough Island-Reavey Deposit. (Lapland.)
Plate XVI. 130.
5. Navicula cuspidata, Kitz. V. acute; striz parallel, distinct, 36 in 001". Length :0027” to 0062". v.v.
Kutz. Bacill. ii. 24 & 37. ad specim. authen. que misit amic. De Brébisson. Navicula fulva, Ehr. Inf. xin. 6.
Fresh water: ditches. Lewes, Sept. 1850, W. Sm. Guildford, Mr. Capron. Belfast, Dr. Dickie. Cantyre Peat. Lough Mourne and Peterhead Deposits.
Plate XVI. 131.
6. Navicula rhynchocephala, [iitz. V. acute; extremities pro- duced, linear; striae distinct, radiate, 24 in ‘001". v.s.
Kitz. Bacill. xxx. 35? Fresh water. Belfast, Dr. Dickie. Plate XVI. 132.
48 BRITISH DIATOMACE.
Sect. II. Valves elliptical, extremities rounded.
7. Navicula Liber, n.sp. F. V. oblong; V. elliptical, with rounded extremities; striz delicate, 48 in ‘001"; colour of dry V. pur- plish. v.v.
Marine. Coast of Sussex, Sept. 1851, W. Sm. Plate XVI. 133.
8. Navicula firma, Kiitz. V. elliptical, somewhat attenuated towards the rounded extremities; striz obscure, 42 in‘001", parallel. Length "0025" to :0045". v.v.
3. Extremities suddenly attenuated ; frustule smaller.
B. Kiitz. Bacill. xxi. 10.
Fresh water. Near Lewes, Oct. 1851, W. Sm. Near Belfast, Dr. Dickie. (3. Lough Mourne and Peterhead Deposits. Cantyre Peat. Marl, Co. Down. (Vermont, U.S., Prof. Williamson. San Fiore, Italy.)
Plate XVI. 138.
9. Navicula elliptica, n. sp. V. elliptical; striz distinct, 21 in 001", interrupted towards the central line. Length -0912" to =003 21; "av.v.
Marine. Poole Bay, Sept. 1850; Seaford, Sussex, Aug. 1851, W. Sm.
Plate XVIT. 152. Var. (Sporangial ?) From Poole Bay, 152 a*. Frustule with endochrome, Frontispiece, fig. CLII.
10. Navicula ovalis, /V. Sm. V. elliptical, occasionally inflated ; strie distinct, 27 in 001", interrupted. Length 0012" to :0020". V.V.
Navicula elliptica, Kitz. Bacill. xxx. 55.
Fresh water. Plumpton, Sussex, April 1852, W. Sm. Guildford, Mr. Capron. Cantyre Peat. Lough Mourne and Peterhead Deposits. Rescobie and Killicrankie, Mr. P. Grant. (Ceylon, Mr. Thwaites, Nov. 1850.)
Plate XVII. 153.
11. Navicula minutula, n.sp. V. exactly elliptical; striz faint, SO im -OO!: Length 0006" to 0011". v.v.
Fresh water. Near Lewes, Oct. i852, W. Sm.
Supp. Plate XXXI. 274.
BRITISH DIATOMACE2. 49
Sect. III. Valves elliptical, extremities acute.
12. Navicula Jennerii, 7. Sm. F.V. oblong ; V. twisted, elliptical ; extremities somewhat acute; stria very distinct, 30 in ‘001", reach-
ing the central line; colour of dry valve a pale purple. Length 0025" to 0068". v.v.
Navicula tumida, Bréb. in Kiitz. Sp. Alg. p. 77. ad specimina quee communi- ceavit cl. De Brébisson in lit. Sept. 1852.
Marine or brackish water. Rye, Mr. Jeaner. Belfast Bay, Aug. 1849, and Coast of Sussex, frequent, Feb. 1852, W.Sm. Menai Straits, Prof. Wil- hamson, July 1852.
Plate XVI. 134. &. outline of F. V.
13. Navicula Westii, n. sp. F. V. oblong; V. straight, elliptical, acute ; strize delicate, scarcely reaching the central line, 38 in -001" ; colour of dry valve a dark purple. Length -0032" to :0042". v.v. Marine: detected by Mr. Tuffen West with the last, May 1852. Shore-
ham Harbour, Nov. 1852, W. Sm.
Plate XVI. 135.
14. Navicula convexa, n. sp. F. V. oblong; V. twisted, acute; strize very distinct, 21 in °001”, not reaching the central line ; dry valve colourless. Length :0048" to :0062". v.v.
Marine. Coast of Sussex, Sept. 1851. Harwich, Mr. Shadbolt, May 1852.
Plate XVI. 136. 6. outline of F. V. Frustule with endochrome, Fron- tispiece, fig. CXXXVI.
15. Navicula elegans, n. sp. V. elliptical acuminate; striz distinct, 24 in ‘001", waved, radiate, absent around the central nodule. Length :0020" to :0032". v.v.
Marine or brackish water. Poole Bay, June 1849, W. Sm. Cockerham Marsh, Lancashire, M7. Johnson.
Plate XVI. 137.
16. Navicula patula, W. Sm. V. elliptical, somewhat acute; striz delicate, 36 in ‘001, not reaching the central line; colour of dry valve purple. Length :0030" to :0040". v.s.
50 BRITISH DIATOMACEX.
Navicula latiuscula, Kitz. Bacill. v.40. specim. authen. misit cl. De Brébisson. Fresh water. Marl, Co. Down. Plate XVI. 139.
17. Navicula palpebralis, Bréb. V. elliptical, acute; strie not reaching central line, 27 in ‘001". Length 0015" to 0032". _v.s. “ Navicula palpebralis,” cl. De Brébisson in lit. Sept. 1852. Marine. Poole Bay, Aug. 1848. Hull, Mr. R. Harrison. Supp. Plate XXXI. 273.
Sect. IV. Valves inflated; extremities rounded.
18. Navicula obtusa, n. sp. V. elliptical, contracted towards the rounded extremities; striz distinct, 33 in ‘001", not reaching the central line. v.s.
Fresh water. Raasay Earth. Marl, Co. Down. Lough Mourne Deposit. Plate XVI. 140.
19. Navicula Semen, Kiitz. V.oval, contracted towards the rounded extremities ; striz distinct, 26 in‘001". v.s. Kitz. Bacill. xxviii. 49.
Fresh water. Peterhead Deposit. Lough Mourne Deposit, &c. Plate XVI. 141.
20. Navicula affinis, ir. V. elliptical, contracted, and linear to- wards the rounded extremities. v.s.
Ehr. in Kiitz. Bacill. xxx. 45 ? Fresh water. Guildford, Mr. Capron. Plate XVI. 143.
21. Navicula inflata, Kiitz. V. elliptical, inflated; extremities ob- tuse; striz distinct, 28 in ‘001". vas.
Kiitz. Bacill. ii. 36. Fresh water. Guildford, Mr. Capron. Peterhead Deposit. Plate XVII. 158.
BRITISH DIATOMACE. |
22. Navicula gibberula, Kiitz. VV. inflated at the centre, linear towards the rounded extremities. v.v. Kitz. Bacill. i. 50*.
Fresh water. Lewes, Feb. 1851, W. Sm. Guildford, Mr. Capron. Lough Mourne Deposit. Cantyre Peat. Marl, Co. Down. Dolgelly Earth. Ben M? Dhui, Mr. P. Grant.
Plate XVII. 160.
Secr. V. Valves with extremities produced.
23. Navicula amphirhynchus, Ej. V. linear, abruptly contracted towards the produced extremities ; striz faint, 48 in °001". Length "0020" to 0036". v.v.
Kitz. Bacill. xxi. 11.
Fresh water. Lewes, Oct. 1851, W. Sm. Lough Mourne and Peterhead Deposits. Premnay Peat and Dolgelly Earth. (San Fiore, Italy.)
Plate XVI. 142.
24. Navicula producta, n. sp. V. elliptical, abruptly contracted towards the produced extremities; striz faint, 42 in ‘001". vv. Fresh water. Lewes, Oct. 1851, W. Sm. East Shalford, Mr. Capron. Plate XVII. 144.
25. Navicula ambigua, Hhr. V. elliptical, gradually contracted towards the obtuse extremities, which are produced ; striz distinct, parallel, 36 in :001". Length 0021” to :0033". v.v.
Ebr. in Kitz. Bacill. xxvii. 66.
Fresh water. Lewes, Oct. 1851, W. Sm. Plate XVI. 149. Frustule with endochrome, Frontispiece, fig. CXLIX.
26. Navicula Amphisbzena, Bory. V. elliptical, constricted towards the extremities, which are rounded and produced; striz delicate, 40in‘001", not reaching the central line. Length 0021"to ‘0032".
6. Extremities slightly produced, obtuse. Length 0017" to 0027". v.v. Kiitz. Bacill. iii. 41 and 42 8. Ehr. Inf. xii. 7. Prit. Anim. iu. 141.
Hass. Alg. cii. 5. EZ
52 BRITISH DIATOMACE.
Fresh water. Lewes, Feb. 1851, W. Sm. Wray, Mr. G. Smith. Guild- ford, Mr. Capron. Var. B. Lewes, April and October, 1852, and Feb. 1853, W. Sm.
Plate XVII. 147. Var. 6. Pl. XVII. 147 6.
27. Navicula sphzrophora, Kiitz. V. elliptical, constricted to- wards the extremities, which are rounded and produced; striz very delicate, 42 in 001". Length :0022" to :0036". v.v.
Kiitz. Bacill. iv. 17. Sp. Alg. p. 75. ad specim. que misit amic. De Bré-
bisson. Fresh water. Lewes, Oct. 1851, W. Sm. Lough Mourne Deposit. Plate XVII. 148.
28. Navicula angustata, n. sp. V. very narrow, elliptical, con- tracted towards the rounded and produced extremities; striz 45 in :001”. Length °0016" to :0022". v.s.
Fresh water. Killicrankie, Mr. P. Grant. Raasay Earth. Plate XVII. 156.
29. Navicula tumens, n.sp. F.V. inflated; V. elliptical, extre- mities slightly produced; striz interrupted, faint, 36 in ‘001". Length *0025" to 0031". v.v.
Brackish water. Newhaven, Sussex, Feb. 1852, W. Sm. Plate XVII. 150. 6. outline of F. V.
30. Navicula punctulata, n. sp. V. oval, extremities scarcely pro- duced ; striz distinct, 33 in 001", moniliform. Length :0016” to 0032". v.v.
Marine. Poole Bay, Sept. 1850, and Seaford, Sussex, Aug. 1851, W. Sm. Plate XVI. 151.
31. Navicula pusilla, n.sp. V. oval, extremities slightly produced ; strie distinct, 26 in ‘001", radiating, punctate. v.v.
Brackish water. Lewes, Oct. 1850, VW. Sm. Near Belfast, Dr. Dickie. Plate XVII. 145.
BRITISH DIATOMACE&. 53
32. Navicula tumida, n.sp. V. elliptical, contracted at the ex- tremities, which are rounded and produced; striz very distinct, 24 in ‘001", reaching central line, punctate and radiate. v.s. Fresh water. Bramley near Guildford, Mr. Capron, Nov. 1850.
Plate XVII. 146.
33. Navicula dicephala, Kitz. V. linear, constricted towards the rounded extremities; striz distinct, 26 in ‘001", radiate. v.s. Kiitz. Bacill. xxviii. 60? Fresh water. Guildford, Mr. Capron. Lough Mourne Deposit. Plate XVII. 157.
34. Navicula cryptocephala, Kiitz. V. minute, constricted to- wards the obtuse extremities; striz faint, 56 in‘001". v.v.
Kitz. Bacill. m1. 20 & 26. Freshwater streams. Corfe Castle, Dec. 1849, W. Sm. Belfast, Dr. Dickie. Plate XVII. 155.
Sect. VI. Valves with a central constriction.
35. Navicula didyma, Kiitz. V. elliptical, more or less deeply con- stricted in the centre; striz interrupted, distinct, 24 in :001". Length 0014" to 0032". v.y.
soe =
Kitz. Bacill. iv. 7. xxvii. 75. Navicula interrupta, Kitz. Bacill. xxix. 93. Pinnularia Apis, Ehr. in Kiitz. Bacill. xxvii. 76.
Marine: very common. Sussex, July 1850, W. Sm. (New Zealand.)
Plate XVII. 154. a. and a’. ordinary forms; 6. outline of ditto in S. D.; a*. var. (Sporangial’?) from Skye, Prof. Williamson. Frustule with endo- chrome, Frontispiece, fig. CLIV.
36. Navicula binodis, Hr. V. constricted in the centre, extremities slightly produced; striz obscure. v.s.
Kiitz. Bacill. iti. 35. Fresh water. Lewes, Aug. 1850, W. Sm. Plate XVII. 159.
54 BRITISH DIATOMACE&.
Genus 20. PINNULARIA, Ehr.
Frustules free, oblong or lanceolate; valves convex, with a median line, and nodules at centre and extremities; ribbed or pinnated with distinct costez not resolvable into dots.
The species in which the cost are absent from the centre of the valve, as noticed at page 46, belong to Ehrenberg’s genus Stauroptera, but the limits of that genus are too indefinite to permit me to adopt it in the present work. 1. Pinnularia nobilis, Hhr. V. linear, obtuse, with a central and
terminal inflation; cost radiate, not reaching the median line,
contiguous, 12 in -001". Length -0112" to 0145". v.s.
Navicula nobilis, Kiitz. Bacill. iv. 24. Sp. Alg. p. 80. ad specim. que misit amic. De Brébisson. Quek. H. C. pl. xii. 1. a.
Fresh water. Lough Mourne Deposit. Dolgelly Earth. Premnay Peat. Cantyre Peat. (Nova Scotia. Vermont, U.S.)
Plate XVII. 161.
2. Pinnularia major, WV. Sm. V. linear, obtuse, with a central in- flation ; costz as in the last, 14 in ‘001". Length :0072" to :0122". V.S.
Navicula major, Kitz. Bacill. iv. 19. Navieula viridis, Ehr. Inf. xiii. 16. Hass. Alg. ci. 2.
Fresh water. Lough Mourne Deposit. Premnay Peat. Dolgelly Earth. Mountains of Aberdeen, Dr. Dickie. Cantyre Peat. Peterhead and Lough Island-Reavey Deposits.
Plate XVIII. 162.
3. Pinnularia viridis, WV. Sm. V. elliptical, attenuated; costz as in the last, 16 in:001". Length -0021" to-0068". _ y.v.
. Costee parallel, absent from centre of valve.
Navicula viridis, Ehr. Inf. xxi. 12. Prit. Anim. i. 133-136. xviii. 1-6. Kiitz. Bacill. iv. 18, 20. Quek. H. C. xii. 1. 6. Navicula viridula, Ehr. Inf. xii. 17.
Fresh water: very common. Wareham, Feb. 1848, W. Sm. Lough Mourne, Lough Island-Reavey, and Peterhead Deposits. Premnay Peat. Dolgelly Earth. Cantyre Peat. (New Zealand, Nova Scotia, &c.) Var. . Lewes, Mar. 1852, WV. Sm. Ben M* Dhui, Mr. P. Grant.
Plate XVIII. 163. Frustule with endochrome, Frontispiece, fig. CLXIII. Var 2. PX VilL. 163.6.
BRITISH DIATOMACE. 55
4, Pinnularia acuminata, n. sp. V. linear, suddenly attenuated towards the acute extremities; costa parallel, not reaching the central line. v.s.
Fresh water. Premnay Peat. Plate XVIII. 164.
5. Pinnularia oblonga, WV. Sm. V. lanceolate, extremities rounded ; coste radiate, reaching central line, distant, 11 in 001". Length 0042" to -0066". v.v.
Navicula macilenta, Ehr. Inf. xxi. 13. Navicula oblonga, Kiitz. Bacill. iv. 21.
Fresh water: common. Lewes, Oct. 1852, W.Sm. Belfast, Dr. Dickie. Peterhead Deposit. Marl, Co. Down.
Plate XVIII. 165. Frustule with endochrome, Frontispiece, fig. CLXV.
6. Pinnularia cardinalis, Hhr. V. linear, extremities rounded; costz radiate, absent from the centre of V., distant, 9 in O01". V.S.
Stauroneis cardinalis, Kiitz. Bacill. xxix. 10. Prit. Anim. xv. 72.
Fresh water. Lough Mourne Deposit. Cantyre Peat. Plate XIX. 166.
7. Pinnularia lata, WV. Sm. V. linear, slightly inflated at the centre ; cost scarcely radiate, not reaching central line, distant, 7 in 001". Length -0025” to 0044". v.v.
Navicula lata, De Brébisson in lit. cum specim. Kitz. Sp. Alg. p. 79.
Fresh water: subalpine. Fell End, Lancashire, at an elevation of 900 feet, Mr. Johnson, May 1851. Snow Mud, on Ben M° Dhui, at an elevation of 3840 feet, Dr. Dickie.
Plate XVIII. 167. d. outline of ditto in S. D.
8. Pinnularia alpina, n. sp. V. elliptical-lanceolate, obtuse; costz radiate, not reaching central line, distant, 7 to 9 in ‘001". Length 0038" to :0083". v.s.
Fresh water: subalpine. Mountains of Aberdeen, Dr. Dickie. Ben M° Dhui,
Mr. P. Grant. (Falaise, M. De Brébisson.)
Plate XVIII. 168. 4. outline of F. V.
56 BRITISH DIATOMACEA.
9, Pinnularia distans, n. sp. V. lanceolate, acute; costz radiate, not reaching central line, distant, 10 in :001". Length -0036" to 0052". -v.8.
Marine. Stomach of Scallop, Feb. 1851. Coast of Sussex, W. Sm. Plate XVIII. 169. 5. outline of F. V.
10. Pinnularia peregrina, Ehr. V. lanceolate, obtuse; costz ra- diate, reaching central line, subdistant, 13 in 001". Length 0032" to 0058". v.v.
Ehr. in Kitz. Bacill. xxvii. 52.
Brackish water. Near Lewes, Nov. 1851, W. Sm. Cockerham Marsh, Lancashire, Mr. Johnson, Mar. 1852.
Platemxevililleal0:
11. Pinnularia acuta, n. sp. V. lanceolate, acute; costz radiate, reaching central line, 22 in ‘001’. Length 0026" to 0046". v.v.
Fresh water. Plumpton, Sussex, Mar. 1852, W. Sm. Lough Mourne Deposit. Near Aberdeen, Dr. Dickie. Cantyre Peat. Marl, Co. Down. Dol- gelly Earth. Peterhead Deposit.
Plate XVIII. 171.
12. Pinnularia directa, n. sp. V. linear-lanceolate, acute; coste parallel, reaching central line, 20 in -001". Length 0025" to 0037". V.V.
Marine. Coast of Sussex, Feb. 1852, W. Sm. Plate XVIII. 172. 6. outline of F. V.
13. Pinnularia radiosa, VV. Sm. V. lanceolate, obtuse ; costz ra- diate, contiguous, 24 in 001". Length 0016" to °0025". _v.v.
Navicula radiosa, Kitz. Bacill. iv. 23?
Fresh water: frequent. Corfe Castle, Dec. 1849, W. Sm. Wray, Mr. G. Smith. Peterhead Deposit. Lough Mourne Deposit. Cantyre Peat. Dol- gelly Earth.
Plate XVIII. 173.
BRITISH DIATOMACEA. 57
14, Pinnularia gracilis, Hhr. V. elliptical-lanceolate, attenuated towards the extremities ; cost radiate, contiguous. Length -0016" to 0022". vv.
Navicula gracilis, Ehr. Inf. xiii. 2? Kitz. Bacill. ili. 48? = Mavicula lan-
ceolata, Hass. Alg. ci. 14.
Fresh water: frequent. Lewes, May 1850, W.Sm. Shalford, Mr. Capron. Plate XVIII. 174.
15. Pinnularia viridula, WV. Sm. V. elliptical-lanceolate, obtuse; coste faint. Length 0006" to -0016". v.v.
Fresh water. Kingston, Sussex, Nov. 1851, W. Sm.
Plate XVIII. 175.
16. Pinnularia Cyprinus, Hhr. V. elliptical, with a central infla- tion; extremities somewhat acute; cost radiate, reaching central line, subdistant, 18 in :001". Length -6016" to -0035". _ v.v.
Ebr. in Kitz. Bacill. xxix. 35?
Marine. Belfast Bay, Aug. 1849, and Coast of Sussex, frequent, Sept. 1851, W. Sm. Harwich, Mr. Shadbolt.
Plate XVIII. 176. 6. outline of F. V.
17. Pinnularia divergens, n. sp. V. linear-elliptical, somewhat attenuated towards the rounded extremities; costz radiate at cen- tre, afterwards divergent, absent from the middle of valve, sub- distant, 11 in 001".
Fresh water. Premnay Peat. Dolgelly Earth. Plate XVIII. 177.
18. Pinnularia stauroneiformis, WV. Sm. V. elliptical; costz ab- sent from the centre of V., not reaching the central line, contiguous, 30 in‘001”". Length -0011” to :0025", v.v.
Navicula Brebissonii, Kitz. Bacill. ii. 49. xxx. 39. Sp. Alg. p. 72. ad specim. quee dedit amicus De Brébisson.
Fresh water. Lewes, Feb. 1852, W. Sm. Ben M° Dhui, at an elevation of 3000 feet, Mr. P. Grant.
Plate XIX. 178.
58 BRITISH DIATOMACE.
19, Pinnularia Johnsonii, n. sp. V. linear, with central and ter- minal inflations ; costz reaching central line, 56in‘001". Length "0042" to :0072". v.v.
8. Inflations very slight. Length 0025" to :0035". v.v.
Marine or brackish water. Pilling near Lancaster, Mr. Johnson, Feb. 1851. 8. Shoreham, Sussex, Mar. 1851, W. Sm.
Plate XIX. 179. Var. 6. Pl. XIX. 179 B.
20. Pinnularia gibba, Hhr. V. linear, with central and terminal inflations; cost not reaching central line, contiguous, 30 in ‘001". V.v.
Navicula acrospheria, Kitz. Bacill. v. 2. Sp. Alg. p. 78. ad specim. quze misit amic. De Brébisson.
Fresh water. Boggy pools, Wareham, Sept. 1847, W. Sm. Curwen Hill, Lancashire, Mr. G. Smith. Cantyre Peat. Premnay Peat.
Plate XIX. 180.
21. Pinnularia Tabellaria, WV. Sm. V. as in the last, but central inflation more distinct; cost subdistant, 22 in O01". v.v.
Navicula tabellaria, Kitz. Bacill. xxviii. 79. Prit. Anim. xv. 21. Fresh water. Lewes, Sept. 1850, W. Sm. Plate XIX. 181.
22, Pinnularia acrospheria, VV. Sm. V. as in the last two; infla- tions more distinct; costa distant, 16 in ‘001". v.v.
Fresh water. Near Lewes, Sept. 1850, W. Sm. Premnay Peat. Dol- gelly Earth.
Plate XIX. 183.
23. Pinnularia mesolepta, Hhr. V. linear, with three central in- flations, deeply constricted towards the obtuse extremities ; costa reaching central line, 24 in ‘001". v.v.
Navicula mesolepta, Kitz. Bacill. xxviii. 73. xxx. 34? Navicula nodosa,
Ehr. Inf. xii. 9.
Fresh water. Ashdown Forest, Sept. 1850, W. Sm. Gardner Street, Sussex, Mr. Jenner. Near Aberdeen, Dr. Dickie. Marl, Co. Down. Lough Mourne Deposit. Dolgelly Earth. Premnay Peat. Cantyre Peat.
Plate XIX. 182.
ee aa
BRITISH DIATOMACE. 59
24. Pinnularia interrupta, W. Sm. V. linear, constricted at the rounded extremities; costz absent from the centre of the valve, contiguous, 24 in 001". Length -0012" to 0022". v.v.
Stauroneis parva, Kiitz. Bacill. xxix. 23. Sp. Alg. p. 92. specim. misit cl. De Brébisson.
Fresh water. With the last, and probably only a variety of the same. Plate XIX. 184.
Genus 21. STAURONEIS, Ehr.
Frustules free, oblong or lanceolate; valves convex; striated, with a median line and terminal nodules; central nodule dilated into a band (Stauros) free from striz.
1, Stauroneis Pheenicenteron, Hhr. V. lanceolate, obtuse; stauros linear, reaching the margin ; striz 33 in 001". Length 0055" to 0066". v.v.
Kitz. Bacill. ii. 53. Navicula Phenicenteron, Ehr. Inf. xii. 1. Prit. Anim. m. 139. xv. 17 & 18:
Fresh water: very common. Wareham, Sept. 1847; Lewes, Aug. 1850; Jersey, Aug. 1852, W.Sm. Lough Mourne and Peterhead Deposits. Prem- nay Peat. Cantyre Peat. (North America.)
Plate XIX. 185.
2, Stauroneis gracilis, Hhr. V. lanceolate, obtuse ; stauros linear, scarcely reaching the margin; strize very delicate, 45 in -001". Length °0028"' to 0036". v.v.
Ehr. in Kiitz. Bacill. xxix. 3?
Fresh water. Bindon Abbey, Dorsetshire, May 1849, W. Sm. Wray near Lancaster, Oct. 1852, Mr. G. Smith. Dolgelly Earth. Lough Mourne Deposit. Cantyre Peat. (Little Falls, New York, and Nova Scotia.)
Plate XIX. 186.
3. Stauroneis acuta, n.sp. F. V. oblong; V. lanceolate, acute, inflected at the extremities; stauros dilated towards the margin of valve; striz 30 in ‘001. Length :0033" to -0057". v.v.
“A species of Navicula,’ Quek. H. C. xii. 26.
60 BRITISH DIATOMACE. Fresh water. Near Guildford, Mr. Capron, Nov. 1852. Lough Mourne Deposit. Cantyre Peat. Premnay Peat. (New Zealand: Nova Scotia.) Plate XIX. 187. Frustule with endochrome, Frontispiece, fig. CLXXXVIT.
4, Stauroneis salina, n. sp. V. elliptical-lanceolate ; stauros linear ; striz faint, 45 in 001". Length :0016" to :0022". v.v. Marine. Shoreham, Aug.1851, W.Sm. Folkestone, Nov. 1852, Mr. Capron. Plate XIX. 188.
5. Stauroneis dilatata, n. sp. V. elliptical, extremities slightly produced; stauros linear, not reaching the margin; stria 30 in OO Ge HEE Fresh water. Aberdeenshire, Dr. Dickie. Cantyre Peat.
Plate XIX. 191.
6. Stauroneis crucicula, n.sp. V. elliptical, extremities slightly produced; stauros very narrow, linear, reaching the margin. v.y.
Marine. Belfast Bay, Aug. 1849, W. Sin. Plate XIX. 192.
7. Stauroneis anceps, Hir. V. elliptical, constricted towards the produced extremities; stauros linear, not reaching the margin; strize very delicate, 45 in ‘001". y.v.
Ehr. in Kiitz. Bacill. xxix. 4?
Fresh water. Swanage, Dorset, March 1849; Lewes, Oct. 1852, W. Sm. Lanshaw Spa, Katefield, Lancashire, Mr. G. Smith, Jan. 1852. Ben M*° Dhui, Mr. P. Grant. Marl, Co. Down.
Plate XIX. 190.
8. Stauroneis linearis, Hir. V. elliptical, inflated at centre and at the extremities, which are apiculated ; stauros linear, reaching the margin; striz obscure. v.v.
Kiitz. Bacill. xxx. 26.
Fresh water. Plumpton and Lewes, Sussex, Apr. 1852, W. Sm. Shalford, Mr. Capron. Premnay Peat.
Plate XTX. 193.
BRITISH DIATOMACE. 61
9, Stauroneis punctata, Kiitz. V. elliptical, extremities produced ; stauros linear, central; striz radiate, punctate, 27 in ‘001". vs.
Kiitz. Bacill. xxi. 9.
Fresh water. Lough Mourne and Peterhead Deposits. Premnay Peat. Ben M° Dhui, Mr. P. Grant. Cantyre Peat. (San Fiore, Italy.)
Plate XIX. 189.
10. Stauroneis pulchella, n.sp. IF. V. oblong, constricted at the centre; V. elliptical; stauros central, dilated towards the margin ; strie very distinct, 30 in :001", punctate; puncta hexagonal. Length °0048" to :0096". v.v.
(. Dry valve purplish, somewhat acuminate.
Marine. Coast of Sussex, Aug. 1850, and Poole Bay, Sept. 1851, W. Sm. §. Torbay, July 1846. Coast of Sussex, Aug. 1850, W. Sm. Near Ipswich, Mr. Hodgson, Aug. 1851. Harwich, Mr. Shadbolt. (Peruvian Guano.)
Plate XIX. 194. 6. outline of F. VV. Var. B. Pl. XIX. 194 pf.
Genus 22. PLEUROSIGMA, IV. Sm.
Frustules free, elongated; valves convex, sigmoid, with a central lon- gitudinal line, and nodules at centre and extremities, striated ; striz resolvable into dots, which are frequently hexagonal.
The sigmoid form of the valve more or less present in all our native species, at once distinguishes this genus from its allies; but even in the absence of this feature, which I have noticed to be wanting in at least one species, discovered by M. De Brébisson, on the coast of Normandy, the structure of the siliceous valve retains its character- istic peculiarities. The strize are invariably so closely arranged, that their discovery and resolution are among the most difficult operations in microscopy. Their true character has been, in consequence, fre- quently mistaken ; some observers having considered these appear- ances of striz to arise from series of perforations, and others from rows of beads, or minute elevations. With the latter I have been disposed to coincide, until, aided by the careful manipulation and excellent object-glasses of Mr. Richard Beck, who has shown me the hexagonal outline of these supposed beads, I have been led to
62 BRITISH DIATOMACE.
conclude, as I have stated in the Introduction, that the lines arise from internal structure; that the appearance both of perforations and elevations may be produced in the same object by a slight alteration in the focus of the instrument; and that such appearances are merely optical illusions, produced by the reflection and refraction of the rays passing through the minute cellular structure of the siliceous epiderm.
It is evident that no optical effect can confer upon circular eleva- tions or perforations hexagonal outlines, while it is easy to see how the latter, when out of focus, or viewed by an object-glass of imper- fect definition, may assume the semblance of rounded beads or dots. And, moreover, as the view which regards the strize of Pleuwrosigma as arising from the cellular arrangement of the epiderm, harmonises the structure of this extensive genus with that of the other members of the family, it seems recommended to our acceptance by claims too strong to be resisted.
Nothing is known of the Reproduction, properly so called, either of this or of the three preceding genera, multiplication by self-division being the only mode of increase hitherto detected. While this pro- cess is actively going forward, the mucus generated by the dividing frustules is often so considerable as to produce the appearance and effect of a distinct frond, which assumes the form of a thin pellicle of some little tenacity. At other times, when the mucous secretion does not assume the continuity of a pellicle, it invests the individual frus- tule with a transparent envelope, which has the appearance of an ex- terior membrane, and has been sometimes mistaken for such. On one occasion I also met with the frustules of P. Hippocampus enclosed in mucous or gelatinous tubes, precisely like those of a Colletonema ; but these conditions must be regarded, for the present at least, as temporary or accidental, and cannot be admitted into the specific or generic descriptions.
Owing to the compression of the valves, the scanty development of the connecting-membrane, and the elongate form of the frustule in the present genus, the front view is either of a linear or linear-lanceo- late form; two examples are given in Pl. XXIII. 203 & 207; but I have omitted a special notice in the case of each species, as I have not found this feature of much assistance in their discrimination. On the other hand, as the colour of the dry valve is often conspicuous, and seems to depend on the structural character of the silicified mem-
BRITISH DIATOMACEX. 63
brane, and also supplies a ready means of discrimination, I have en- deavoured to record it with as much precision as possible. From notices forwarded by Mr. Beck, I am disposed to conclude that a yellow tint in the valve indicates the presence of a distinct hexagonal structure in its cellular condition, and a purple colour an absence of such character.
In several species the striae are so closely arranged—or, in other words, the cellular structure is so minute,—that the power I have ordi- narily employed has proved insufficient for their resolution. In such cases I have availed myself of Mr. Beck’s aid, who has succeeded, with an object-ylass of 4-inch focal length and angular aperture of 120°, in resolving the lines on most of the species alluded to.
Sect. I. Striz oblique.
1. Pleurosigma formosum, JV. Sm. V. linear-lanceolate, twisted, flexure considerable, extremities obtuse; median line not central ; colour light chestnut-brown ; striz 36 in ‘001". Length 0141" to Ol S i. AViVec
W. Sm. Ann. 2nd Ser. vol. ix. p. 5. pli. 1. Prit. Anim. xix. 1.
Marine. Shoreham Harbour, Aug. 1850, W. Sm. Walton, Essex, Mr. C. Topping.
Plate XX. 195. Frustule with endochrome, Frontispiece, fig. CXCV.
2. Pleurosigma decorum, n. sp. V. lanceolate, acute, angular, twisted, flexure considerable; median line not central; colour pale chestnut; striz 36 in ‘001". Length 0098" to °0125". v.s. Brackish water. Ipswich, Mr. 7. Hodgson, Aug. 1851. Felixstow, Essex,
Mr. C. Topping.
Plate XXI. 196.
3. Pleurosigma speciosum, /V. Sm. V. linear-lanceolate, obtuse; flexure slight, twisted; median line subcentrai; colour a pale straw; striz 44 in ‘001". Length :0083" to :0152". v.s.
W. Sm. Ann. 2nd Ser. vol. ix. p. 6. pl.i. 3. Prit. Anim. xix. 3. Marine. Walton, Essex, Aug. 1851, Mr. C. Topping. Plate XX. 197.
64 BRITISH DIATOMACES.
4, Pleurosigma rigidum, n.sp. V. linear-lanceolate, flexure slight, extremities rounded, median line central ; colour pale straw ; striz 48 in ‘001". Length OL 1G" to <0 2!) vas:
Brackish water. Ipswich, Mr. T. Hodgson, Aug. 1851. Plate XX. 198.
5. Pleurosigma elongatum, WV”. Sm. V. lanceolate, flexure mode- rate, extremities acute; colour a clear straw; striz 48 in ‘001". Length °0083" to 0152". v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 6. pl.i. 4. Prit. Anim. xix. 4.
Marine and brackish water. Poole Bay, June 1849; Coast of Sussex, Oct. 1850, W. Sm. Hull, Mr. R. Harrison.
Plate XX. 199.
6. Pleurosigma intermedium, n. sp. V. lanceolate, flexure very slight, extremities acute; colour pale straw; “stria 55 in “001? (R. B.) Length -0066" to 0088". v.y.
Marine. Newhaven, Sussex, Mar. 1852, W. Sm. Ipswich Harbour, Mr. Topping, April 1852.
Plate XXI. 200.
7. Pleurosigma WNubecula, n. sp. V. linear-lanceolate, obtuse, flexure hardly perceptible; colour very pale; “strize 55 in 001".” (R. B.) Length :0055" to -0066". v.v.
Marine. Seaford, Sussex, Mar. 1852. Plate XXI. 201.
8. Pleurosigma delicatulum, /V. Sm. V. lanceolate, acute, flexure moderate; colour pale pink; striz 64 in 001". Length -0058" to 70108". v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 6. pl.i. 5. Prit. Anim. xix. 5.
Brackish water. ‘‘ Brooks”’ near Lewes, Oct. 1850 and Sept. 1852, W. Sm. Plate XXI. 202.
9, Pleurosigma strigosum, /V. Sm. V. lanceolate, obtuse, flexure slight; colour pale straw; strie 44 in ‘001. Length -0066" to 0) eee
BRITISH DIATOMACE&. 65
W. Sm. Ann. 2nd Ser. vol. ix. p. 7. pl.i. 6. Prit. Anim. xix. 6.
Marine. Coast of Sussex, Aug. 1850 and Mar. 1852, W. Sm. Rye» Mr. Jenner. Hull, Mr. R. Harrison.
Plate XXI. 203. Outline of F. V. Pl. XXIII. 203.
10. Pleurosigma quadratum, n. sp. V. quadrangular, acute, flex- ure moderate ; colour chestnut ; striae 45 in 001". Length 0030" teOl05". vv.
Pleurosigma angulatum, W. Sm. Ann. 2nd Ser. vol. ix. p. 7. pl. i. 7 & 9.
Prit. Anim. xix. 7 & 9.
Marine or brackish water. Poole Bay, Aug. 1849; Coast of Sussex, Aug. 1850; Braunton, Devonshire, Mr. Ralfs. Menai Straits, Professor Williamson, July 1852. Folkestone, Mr. Capron, Nov. 1852.
Plate XX. 204. Outline of a young (?) specimen, 204 (3.
11. Pleurosigma angulatum, WV. Sm. V. lanceolate, angular, acute ; colour pale chestnut; striz 52 in -001". Length -0066" to -0100". V.V.
Pleurosigma angulatum 3, W. Sm. Ann. 2nd Ser. vol. ix. p. 7. pl. i. 8. Prit.
Anim. xix. 8. Navicula angulata, Quekett on the Microscope, 1848, p- 438. pl. viii. 4, 5, 6, 7.
Marine or brackish water. Poole Bay, Aug. 1848 ; Belfast Bay, Aug. 1849 ; Coast of Sussex, April, May and Aug. 1852, W. Sm. Coast of Lancashire, Mr. Johnson. Rye, Mr. Jenner. Hull, Mr. R. Harrison. Coast of Norfolk, Mr. Brightwell.
Plate XXI. 205.
12. Pleurosigma A&stuarii, W. Sm. FF. frequently direct; V. broadly lanceolate ; extremities obtuse, somewhat produced, flexure of median line considerable; colour a pale purple; striz 54 in 7001". Length :0028" to :0052". v.v.
Navicula Astuarii, De Bréb. in Kiitz. Sp. Alg. p. 890. ad specim. authen.
que misit cl. De Brébisson, Oct. 1852. Marine or brackish water. Shoreham Harbour, Nov. 1852, W. Sm. Supp. Plate XXXI. 275.
13. Pleurosigma obscurum, JV. Sm. V. linear, slightly attenuated, obtuse, median line not central; colour pale pink; “striz 75 in 001".” (R. B.) Length -0036" to -0062". v.v.
6. A much smaller form: marine. W. Sm. Ann, 2nd Ser. vol. ix. p.8. pl.i. 11 & 12. Prit. Anim. xix. 11 & 12. F
66 BRITISH DIATOMACE.
Marine or brackish water. ‘‘ Brooks,” Lewes, Sept. 1850. Var. (3. in- vesting a sponge, Poole Bay, Nov. 1849, W. Sm.
Plate XX. 206. Outline of smaller var. 206 6.
Sect. II. Striz transverse and longitudinal.
14, Pleurosigma Balticum, /V/. Sm. V. linear, attenuated towards the obtuse extremities, flexure terminal; colour dark brown; long. and trans. striz 38 in ‘001". Length :0083" to 0142". v.v.
(. Smaller, more gradually attenuated. y. Attenuated throughout ; striz obscure.
W. Sm. Ann. 2nd Ser. vol. ix. p. 8. pl. ii. 1, 2 & 3. Prit. Anim. iii. 144. xx. 1, 2,3. Navicula Baltica, Ehr. Inf. pl. xii. 10. Kiitz. Bacill. iv. 32.
Marine or brackish water: frequent. Poole Bay, Aug. 1848. Belfast Bay, Aug. 1849. Coast of Sussex, Aug., Sept., Oct. and Nov. 1850, WW. Sm. Cockerham Marsh, Lancashire, Oct. 1849, Mr. Johnson. 3. & y. Coast of Sussex, Oct. 1851, W. Sm.
Plate XXII. 207. Outline of young (?) specimens, 207 (6. & 207 y. Out- line of F. V. Pl. XXIII. 207. Frustule with endochrome, Frontispiece, fig. CCVII.
15. Pleurosigma Strigilis, 1”. Sm. V. lanceolate, acute, flexure considerable; colour pale brown; long. striz 40 in ‘001"; trans. strie 36 in ‘001". Length :0116" to 0142". v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 8. pl. ii. 4. Prit. Anim. xx. 4.
Brackish water. Hull, Mr. R. Harrison. ford, Sussex, Oct. 1852, W. Sm. Plate XXII. 208.
16, Pleurosigma acuminatum, JV. Sm. V. lanceolate, acute, flex- ure considerable; colour pale brown; long. striae 40 in ‘001"; trans. striz 52 in 001". Length :0050" to :0065". _v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p.9. pl. ii. 5. Prit. Anim. xx.5. Navicula
Stigma, Khr. Inf. xin. 12. Prit. Anim. iii. 146. Kiitz. Bacill. iv. 26. Marine. Shoreham Harbour, June 1850, W”. Sm. Menai Straits, Prof. Wilhamson. Higham, Mr. Shadbolt. Folkestone, Mr. Capron, Nov. 1852.
Plate XXJ. 209.
BRITISH DIATOMACEA. 67
17. Pleurosigma distortum, /V. Sm. V. lanceolate, abruptly bent towards the obtuse extremities; colour pale pink; “ trans. striae 75 in :001"; long. stria 65 in ‘001".” (R. B.) Length 0026" to :0042". V.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 7. pl.i. 10. Prit. Anim. xix. 10.
Marine. Coast of Sussex, Aug. 1850, W. Sm. Folkestone, Mr. Capron.
Plate XX. 210.
18. Pleurosigma Fasciola, /V.Sm. V. lanceolate, extremities pro- duced, flexure considerable; colour pale pink; trans. striz 64 in -Oo1". Length 0036" to -0048". v.v.
(3. Extremities abruptly bent.
Ceratoneis Fasciola, Kiitz. Bacill. iv. 4.
Marine. Belfast Bay, Aug. 1849. Poole Bay, Sept. 1850. Hastings, Nov. 1851, W. Sm. Hull, Mr. R. Harrison.
Plate XXI. 211. Var. 6. 211 a’.
19. Pleurosigma macrum, n. sp. V. lanceolate, extremities pro- duced, flexure terminal, moderate; “trans. striz 85 in:001".” (R. B.) Length 0083" to :0106". v.v.
Brackish water. I=ford, Sussex, Oct. 1852, W. Sm. Supp. Plate XXXI. 276.
20. Pleurosigma prolongatum, /V. Sm. V. lanceolate, narrow, acute, flexure moderate ; “ trans. striz 65 in :001".” (R. B.) Length 0043" to 0060". v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 9. pl. i. 7. Prit. Anim. xx. 7.
Marine. Poole Bay, Oct. 1849. Shoreham, Sept. 1852, W. Sm. Plate XXII. 212.
21, Pleurosigma tenuissimum, n. sp. _V. very narrow, linear-lan- ceolate, acute, flexure considerable ; striz 48 in ‘001". v.s.
Brackish water. Walton, Essex, Mr. Topping, April 1852. Plate XXII. 213.
22. Pleurosigma littorale, WV. Sm. V. broadly lanceolate, acute, flexure considerable; colour purplish; long. striz 24 in ‘001"; trans. striz 50 in ‘00L". Length :0046" to 0063". v.v.
F2
68 BRITISH DIATOMACE.
W. Sm. Ann. 2nd Ser. vol. ix. p. 10. pl. ii. 8. Prit. Anim. xx. 8.
Marine. Coast of Sussex, Nov. 1850, W. Sm. Southampton, Mr. Jenner. River Orwell, near Ipswich, Mr. Hodgson. (Coast of Normandy, M. De Brébisson.)
Plate XXII. 214.
93. Pleurosigma Hippocampus, /V. Sm. V. broadly lanceolate, obtuse, flexure considerable ; colour pale brown ; long. strize 32 in 001"; trans. striz 40 in :001". Length 0050" to :0066". _v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 10. pl. ii. 9, 10. Prit. Anim. xx. 9, 10.
Navicula Hippocampus, Ehr. Inf. xiii. 11? Kitz. Bacill. iv. 29? Prit. Anim. i. 145.
Brackish water. ‘ Brooks”? near Lewes, Sept. 1850, W. Sm. Hull, Mr. R. Harrison. Titchwell, Norfolk, Mr. Brightwell, Sept. 1851.
Plate XXII. 215. Outline of young (?) specimen, 215 £.
24, Pleurosigma attenuatum, WV. Sm. V. lanceolate, obtuse, flex- ure moderate; colour purplish brown; long. striz 30 in -001", trans. striz 40 in :001". Length ‘0075" to :0108". v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 11. pl. i. 11, 12 & 13. Prit. Anim. xx.
11, 12 & 13. Navicula Hippocampus, Quekett on the Microscope,
pl. viii. figs. 1, 2,3. Dujar. Inf. xx. 1. Gyrosigma Hippocampa, Hass. Alg. cit. 11? Navicula attenuata, Kitz. Bacill. iv. 28.
Fresh water: frequent in streams and ditches. River Froome, Dorsetshire, May 1849; Plumpton, Sussex, and many other places, Apr. 1851, W. Sm. Guildford, Mr. Capron. Lough Mourne Deposit. Peterhead Deposit. Can- tyre Peat.
Plate XXII. 216. Outline of F. V. in 8. D. 216d. Outline of young (?) specimen, 216 /.
25, Pleurosigma lacustre, WV. Sm. V. lanceolate, acute, flexure considerable ; colour pale brown ; long. and trans. striae 48 in ‘001". Length :0052" to :0068". v.v.
W. Sm. Ann. 2nd Ser. vol. ix. p. 12. pl. ii. 14. Prit. Anim. xx. 14. Fresh water. Brooks and ponds near Lewes, Oct. 1851, W. Sm.
Plate XXI. 217.
26. Pleurosigma Spencerii, WV. Sm. V. lanceolate, obtuse, flexure slight; colour pale brown; “trans. striz 50 in -001", long. striz 55 in -001".” (R. B.) Length -0033” to 0041". v.v.
BRITISH DIATOMACE. 69
W. Sm. Ann. 2nd Ser. vol. ix. p. 12. pl. ii. 15. Prit. Anim. xx.15. Navicula Spencerii, Quekett on the Microscope, pl. ix.
Fresh water. Near Lewes, Sept. 1850, W. Sm. Reading, Mr. C. Poulton. Plate XXII. 218.
Genus 23. SYNEDRA, Lhr.
Frustules attached, elongate, rectangular ;_ valves linear or lanceolate, plane or convex.
In the present genus the frustules, though often found in a free state, are at first invariably attached to larger Algee, or other plants, by a cushion-like pedicel, which, in a few cases, becomes developed into a more or less distinct stipes. In some species the frustules, after self-division, are speedily detached from this gelatinous cushion, which in such cases rarely presents us with more than two or four individuals, as in 8. /unaris. In others, the frustules, after repeated division, still remain adherent to their pedicel; and the result is a fan-like band of frustules, as in S. pulchellu, or a stellate cluster, as in S. radians. The valves are usually furnished with a central pseudo-nodule and median line, the extremities of which are slightly dilated; but these characters are variable, and not unfrequently ab- sent, and are therefore inadmissible in the generic description.
Secr. I. Pseudo-nodule obsolete or very minute; frustule arcuate.
1. Synedra lunaris, Ehr. V. narrow, linear, slightly attenuated, obtuse; striz 36 in :001". Length :0025" to -0038". v.v. Ehr. Inf. xvii. 4. Kiitz. Bacill. xiii. i. 5.xv.1. Prit. Anim. iv. 185. Ha- laria lunaris, Hass. Alg. xevii. 4.
Fresh water. Boggy pools, Dorsetshire, Dec. 1849; near Lewes, Nov. 1852, W. Sm. Coldbath Spring, Tunbridge Wells, Mr. Jenner, Apr. 1842. Lancashire, Mr. Johnson, Apr. 1852.
Plate XI. 82.
2. Synedra biceps, WV. Sm. V. linear, inflated at the obtuse extre- mities; stric 48 in ‘001. Length ‘0042" to 0075". v.v.
Eunotia flexuosa, Kitz. Sp. Alg. p. 6. ad specim. authen. que misit cl. De Brébisson, Jan. 1853.
70 BRITISH DIATOMACE.
Fresh water. Boggy pools, Dorsetshire, Dec. 1849, W. Sm. Dolgelly, Mr. Ralfs.
Plate XI. 83.
Sect. II. Pseudo-nodule definite, annular.
3. Synedra pulchella, Kiitz. V. lanceolate, slightly constricted to- wards the obtuse extremities ; pedicel frequently dilated into a com- pressed dichotomous stipes; frustules forming flabella; striz 33 in 001". Length 0018” to -0046". v.v.
Kiitz. Bacill. xxix. 87.‘ Ctenophora pulchella,” Bréb. sic cl. De Brébisson in literis cum specim. Oct. 1852.
Fresh water. Penzance, Mr. Ralfs. Jersey, Aug. 1852, W. Sm. Plate XI. 84. Supp. Plate XXX. 84*.
4. Synedra gracilis, Kiitz. V. as in the last; pedicel not dilated ; pseudo-nodule less distinct ; frustules scattered ; strize 39 in -001". Length :0018" to 0041". v.v.
Kiitz. Bacill. mi. 14. xiv. 2. xv. 8.
Brackish water. Poole Bay, Mar. 1848. ‘“ Brooks”’ near Lewes, Apr. 1851, W. Sm.
Plate XI. 85. Frustules with endochrome, Frontispiece, fig. LXXXV.
5. Synedra acicularis, V7. Sm. V. lanceolate, acute; striz very faint, 36 in 001". Length :0022" to :0055"._v.v. Synedra levis, Kitz. Bacill. xv. 8?
Brackish water. Poole Bay, June 1849. Excet, Sussex, March 1850. Lancing, Sussex, Aug. 1852.
Plate XI. 86.
6. Synedra minutissima, Jiitz. V. linear-lanceolate, extremities obtuse; striz 36 in ‘001. Length :0009" to 0021". v.v. Kiitz. Bacill. iii. 30?
Fresh water. Birkenhead, Cheshire, Mr. Shadbolt. Near Lewes, Oct. 1850, W. Sm.
Plate XI. 87.
BRITISH DIATOMACE. 71
Ssecr. III. Pseudo-nodule indefinite.
7. Synedra salina, n. sp. V. lanceolate, gradually attenuated to- wards the somewhat obtuse extremities ; striz distinct, 32 in ‘O01". Length 0075" to :0142". v.v.
Marine. Poole Bay, June 1848, W. Sm. Plate XI. 88.
8. Synedra radians, WV. Sm. V. linear-lanceolate, extremities some- what dilated, obtuse; frustules arranged in a radiate manner ; striae 24 in 001". Length :0050" to °0116". v.v.
Synedra splendens, Kiitz. Bacill. xiv. 16. ad specim. quee misit amic. De Bré- bisson. Hwvilaria Ulna, Hass. Alg. xevii. 2. ad specimina que communi- cavit cl. Jenner. Diatoma truncatum, Grev. B. F. p. 407.
Fresh water: verycommon. Plumpton, Sussex, Apr. 1852, WV. Sm. Speld- hurst, Kent, May 1843, Mr. Jenner. Cheshunt, Dec. 1842, Mr. Hassall. Lough Mourne and Peterhead Deposits.
Plate XI. 89. Pl. XII. 89 8. 89 y. Frustules with endochrome, Frontis- piece, fig. LXX XIX.
9, Synedra Ulna, hr. V.lanceolate-acute; frustules not radiating ; strie 24 in :001". Length -0028" to °0085"._ v.v. §. V. lmear, suddenly acuminated. f. Kitz. Bacill. xxx. 28. Fresh water: common. St. Brelades, Jersey, Aug. 1852. Plate XI. 90. Var. (. Pl. XI. 90 £.
10. Synedra Oxyrhynchus, Miitz. V. lanceolate, suddenly attenu- ated towards the very acute extremities. v.v.
Kiitz. Bacill. xiv. 8, 9, 10, 11? Fresh water. Near Lewes, Feb. 1852, W. Sm. Plate XI. 91.
11. Synedra obtusa, JV. Sm. V. linear, extremities rounded ; striz 24 in ‘001". v.v.
Synedra Ulna, Uhr. Inf. xvii. 1? S. equalis, Kiitz. Sp. Alg. p. 45. ad specim. quee dedit amic. De Brébisson.
72 BRITISH DIATOMACE&.
In ponds: not uncommon. Lewes, Feb. 1852, W. Sm.
Plate XI. 92.
The last four species are so closely allied, that it is difficult, by a verbal description, to assign precise characters to each; a close mspection of the figures will assist in their discrimination, but it will probably be found neces-
sary, upon a further and wider examination, to unite some of those that I have here felt myself obliged to separate.
12. Synedra capitata, Hr. V. linear, dilated towards the acute extremities into a triangular head; striz 23 in ‘001". Length 0078" to °0185". v.v.
Ehr. Inf. xxi. 29. Prit. Anim. iv. 185. Kitz. Bacill. xiv. 19. Evzilaria capitata, Hass. Alg. xevu. 1.
Fresh water: common. Wareham, Sept. 1849, W. Sm. Lough Mourne and Peterhead Deposits.
Plate XII. 93.
13. Synedra delicatissima, n. sp. V. elongated, very narrow and gradually tapering to the somewhat acute extremities; striae 27 in 001". Length -0048" to 0092". v.s.
Fresh water. Lough Neagh, Dr. Dickie, 1850. Plate XII. 94.
14. Synedra longissima, n. sp. V. much elongated, slightly and gradually attenuated towards the inflated and obtuse extremities ; stria 28 in 001". Length 0093" to -0183". v.s.
Fresh water. Pond in Botanic Garden, Belfast, 1850, Dr. Dickie. Plate XII. 95. .
15. Synedra tabulata, Kiitz. V. slightly tapering towards the some- what inflated and obtuse extremities ; striz marginal, 27 in :001" ; frustules united into rectangular tablets. Length 0058" to 0087". V.v.
Kitz. Bacill. xv. 10?
Brackish water. Near Lewes, Sept. 1851, W. Sm.
Plate XII. 96.
BRITISH DIATOMACE. a
16. Synedra affinis, Kiitz. V. lanceolate, acute; striz marginal, 32 in ‘001"; frustules united in flabellate or radiating bundles. Length "0021" to 0046". v.v.
Kiitz. Bacill. xv. 6, et 11. ad specim. authen. quee dedit amic. De Brébisson. Marine. Pevensey Bay, Sussex, Apr. 1851. Plate XII. 97.
17. Synedra Arcus, Kiitz. V. lanceolate, acute; striz marginal, 30 in :001"; frustules on F. V. arcuate, flabellate. Length -0028" to 0038". v.v.
Kitz. Bacill. xxx. 50?
Marine. Cuckmere, Sussex, Mar. 1851; Jersey, Aug. 1852; Hastings, Oct. 1852, W. Sm.
Plate XI. 98. Plate XII. 98.
18. Synedra hamata, n. sp. V. linear, or linear-lanceolate, suddenly attenuated constricted and bent towards the extremities; stricz marginal, 30 in ‘001". Length -0024" to 0052". v.v.
Fresh water. Plumpton, Sussex, Apr. 1852, W. Sm. Supp. Plate XXX. 264.
19. Synedra Vaucheriz, Kiitz. VV. linear-lanceolate; striz mar- ginal, 30 in 001"; frustules somewhat flabellate. Length -0011" to 0018". v.v.
Kiitz. Bacill. xiv. 4?
Fresh water : frequently attached to Vaucheria dichotoma and V. cespitosa. Lewes, Oct. 1851.
Plate XI. 99.
20. Synedra fasciculata, Kiitz. V. linear-lanceolate ; striz reach- ing across the valve, 40 in -001"; frustules in rectangular tablets. v.v.
Kiitz. Bacill. xv. 5? Ewilaria fasciculata, Wass. Alg. xevii. 3. ad specim. authen. que communicavit cl. Jenner.
Fresh water. Plumpton, Sussex, Apr. 1802, W. Sm.
Plate XI. 100.
74 BRITISH DIATOMACE.
Secr. IV. Pseudo-nodule obsolete; frustule straight.
21. Synedra crystallina, Kiitz. V. much elongated, slightly in- flated at the centre and extremities; strie reaching across the valve, 26 in ‘001. Length 0180" to :0266". v.v.
Kiitz. Bacill. xvi. 1. Diatoma erystallinum, Ag. Consp. p. 52. et Grev. B. F. p- 407. ad specim. authen. quee communicavit cl. Dr. Greville.
Marine. Poole Bay, Sept. 1851, W. Sm. Plate XII. 101.
22. Synedra superba, Kiitz. V. linear, slightly attenuated from the centre towards the rounded extremities; striz very distinct, 27 in ‘001", reaching across the valve ; pedicel somewhat elongated. Length of frustule -0098" to °0205". v.v.
Kitz. Bacill. xv. 13. Marine. Poole Bay, Nov. 1849, W. Sm. Plate XII. 102.
23. Synedra Gallionii, Hir. V. attenuate, extremities obtuse ; striz not reaching across the valve, 36 in ‘001"; pedicel not elongated. Length of frustule 0060" to 0112". v.v.
(3. A shorter and stouter form.
Ehr. Inf. xvii. 2. Kiitz. Bacill. xxx. 42. Marine. Isle of Man, Mr. Johnson. 3. Beachy Head, Aug. 1852, W. Sm. Supp. Plate XXX. 265. Var. 6. Supp. Pl. XXX. 265 £.
24. Synedra fulgens, WV.Sm. V.slizhtly inflated at the centre and at the rounded extremities; striz reaching across the valve, 36 in 001"; frustules arranged in a flabellate manner upon a branched pedicel. Length :0068" to °0164". v.v.
Exilaria fulgens, Grev. 8.C. F. pl. 291. Liemophora fulgens, Kitz. Bacill.
xii. 5. ad spec. authen. que misit amicus De Brébisson, Jan. 1853. Prit. Anim. xvi. 20. Marine. Poole Bay, Sept. 1851; Jersey, Aug. 1852, W. Sm. Plate XII. 103. There is nothing in the structure of the frustule to warrant the separation of this species from the present genus.
BRITISH DIATOMACEZ. 75
Genus 24. COCCONEMA, Fir.
Frustules stipitate, cymbiform ; valve with a submedian line, having nodules at centre and extremities.
The frustules of this genus differ in no respect from those of Cym- bella (Genus 3), and are placed apart solely from the presence of a stipes. Whether the development of this accessory be esteemed a generic difference or not, it cannot be denied that it gives a notable physiognomy to the plant, and affords a ready means of discrimi- nation. The stipes seems to be an exudation from the frustule, secreted only during the progress of self-division. It assumes, in the present and other genera, a membranous consistency and filamentous form; while the same secretion is present in Cymbéella and many of the free Diatomaceous forms as a mucous stratum, and in others as a gelatinous cushion or prolonged pedicel.
Where it possesses a filamentous character it invariably branches in a dichotomous manner,—a necessary consequence of the self-division of the frustules, and the circumstance that each filament or branch is the secretion of a separate frustule. Thus, when self-division is com- pleted, the extension of the filament below the frustules is suspended, a joint or articulation is formed at the base of the dividing frustule, aud each of the half-new frustules begins anew, in its progress towards special self-division, the secretion of a new joint or internode; and a dichotomy is the result. Conjugation and the formation of Sporangia in the present genus have been observed by Mr. Thwaites in C. lan- ceolatum and C. Cistula, and by myself in both these species and C. parvum.
1. Cocconema lanceolatum, Hir. F.V. lanceolate, obtuse; V. elon- gated, slightly inflated at the centre of the concave margin ; striz moniliform, 21 in ‘001". Length -0043" to 0058". v.v.
(3. Much elongated (Sporangial?). Length -0083!" to :0098".
Ehr. Inf. xix. 6. Kiitz. Bacill. vi. 3. Dujar. Inf. xx. 4. Prit. Anim. iv. 195. Hass. Alg. ci. 1. In Conjugation, Thw. Ann. vol. xx. pl. xxii. C.
_ Fresh water: frequent. In Conj. River Froome, Dorsetshire, Mar. 1847. Cockshut stream near Lewes, Ap. 1850. Plumpton, Sussex, Ap. 1852, WV. Sm.
76 BRITISH DIATOMACE.
Aberdeenshire, frequent, Dr. Dickie. Lough Mourne and Peterhead De- posits. Premnay Peat. Dolgelly Earth. Marl, Co. Down. Cantyre Peat. Lough Island-Reavey Deposit. (Little Falls, N. Y., Oregon, and Nova Scotia; New Zealand.) 3. Lough Neagh, Dr. Dickie.
Plate XXIII. 219. Frustules with endochrome, Frontispiece, fig. CC XIX.
2, Cocconema cymbiforme, Hir. F.V. linear-oblong; V. narrow, concave margin scarcely inflated; striz moniliform, 21 in :001". Length :0016" to :0032". v.v.
Ehr. Inf. xix. 8. Kitz. Bacill. vi. 12. Hass. Alg. ci. 2.
Fresh water: not so frequent as the last, and scarcely distinct from it. Near Wareham, Apr. 1848; Lewes, May 1851, W.Sm. Near Bristol, Mr. Thwaites. Wray, Lancashire, Mr. G. Smith. Lough Mourne and Peterhead Deposits. Marl, Co. Down. Cantyre Peat.
Plate XXIII. 220.
3. Cocconema Cistula, Hir. F. V. nearly linear, obtuse; V.much bent, distinctly inflated on the concave margin, obtuse ; strize moni- liform, 24 in 001". Length :0008" to :0034". v.v.
Ehr. Inf. xix. 7? Kiitz. Bacill. vi. 1. Hass. Alg. ci. 3. In Conjugation, Thw.
Ann. vol. xx. pl. xxu. E. Cymbella reniformis, Ag. Consp. p. 10. ad specim. authen. que misit cl. Dr. Greville.
Fresh water: frequent. Near Lewes, Mar. 1850. In Conj. Plumpton, Sussex, Apr. 1852, &c., W. Sm. Aberdeenshire, Dr. Dickie. Lough Mourne Deposit. Dolgelly Earth, &c. &e.
Plates XXIII. 221. XXIV. 221. Frustules with endochrome, Frontis- piece, fig. CCXXI.
4, Cocconema parvum, n. sp. F. nearly direct; F. V. oblong; V. scarcely inflated on concave margin; striz moniliform, 21 in 001". Length -0009" to :0016". v.v.
Fresh water. Surface of Chalk cliff, Beachy Head, Aug. 1850. In Con). Apr. 1851, W. Sm.
Plates XXIII. 222. XXIV. 222.
BRITISH DIATOMACEZ.
“I Lo |
Genus 25. DORYPHORA, Kiitz.
Frustules stipitate, lanceolate, or elliptical ; valve with a median line ; nodules obsolete.
Distinguished from the last by the median line dividing the valve into two symmetrical parts, and by the absence of distinct nodules. The second species, upon which the genus has been founded by Pro- fessor Kiitzing, has been seen by him in its living state, attached by a short stipes to larger Algae. I have only found it in my gatherings after the frustules have become detached from their filaments; but the first species has occurred to me abundantly in a living state, and I have been able to refer it with confidence to the present genus, to which it is more closely allied than to Cocconema, with which genus writers have hitherto classed it.
1. Doryphora Boeckii, WV. Sm. F. V. lanceolate, obtuse; V. lan- ceolate, acute; striz moniliform, 24 in :001". Length :0026" to 70053". v.v.
Cocconema Boeckii, Ehr. Inf. xix. 5. Kiitz. Bacill. vi. 5. Quek. H.C. xii. 7.
Marine. Poole Bay, Mar. 1849, W. Sm. Plate XXIV. 223.
2. Doryphora Amphiceros, Kiitz. V. orbicular, elliptical, or ellip- tical-lanceolate; striz moniliform, 18 in ‘001". Length 0012" to "0033!5, -v.8:
Kiitz. Bacill. v. 10. xxi. 2. Prit. Anim. xvii. 21. Rhaphoneis, Ehr. in Bail. Sound. 61-65.
Marine. Poole Bay, Sept. 1851, &c., W. Sm. River Thames, Mr. Shad- bolt. Near Ipswich, Mr. Hodgson.
Plate XXIV. 224. a! and a", outlines of other forms.
Genus 26. GOMPHONEMA, 49.
Frustules stipitate, cuneate; valves variable in outline, striated, with a median line and nodules at centre and extremities.
The cuneate form of its frustules, arising from the unequal develop- ment of the connecting-membrane, distinguishes Gomphonema from
78 BRITISH DIATOMACE.
the genera which have preceded it, and the presence of nodules in its valves from Podosphenia and Rhipidophora, with which the pre- sent genus has sometimes been confounded. The latter genera are also exclusively marine, while the species of Gomphonema, with one exception (and that a species doubtfully connected with the present genus), are all inhabitants of freshwater streams and ponds. The same mode of branching characterizes the stipes of the present genus as that noticed under the genus Cocconema; and excluding the excep- tional species just mentioned, this appendage, in the present as in that genus, when fully developed, consists of an elongated dichotomous filament. Conjugation and the formation of Sporangia have been observed by Mr. Thwaites in G. Berkeleyi, G. tenellum, and G. curva- tum; and by myself in those species, G. capitatum and G. marinum.
1. Gomphonema geminatum, 4g. F.V. slightly cuneate, truncate ; V. inflated at the centre and constricted towards each extremity, of which the one more distant from the stipes (the upper) is enlarged and rounded; striz moniliform, 24 in :001". Length -0041" to ODE MEE eee
Ag. Syst. p.12. Grev. C. F. pl. 244. fig. 2. Harv. Man. p. 207. Realfs, Ann. vol. xu. pl. xvii. 3. Hass. Alg. xevii. 1. Kiitz. Bacill. xiii. 2. Echinella geminata, Lyng. Tent. lxx. p. Gomp. ampullaceum, Grey. B. F. p- 410. ex specim. authen. quee communicavit cl. Dr. Greville.
Fresh water: subalpine streams, not uncommon. Pentland Hills, Dr. Greville. Dolgelly, Mr. Ralfs. Wray, Lancashire, Mr. G. Smith. Ben M* Dhui, Mr. P. Grant. Aberdeenshire, Dr. Dickie. Lough Mourne De- posit. Dolgelly Earth.
Plate XXVIT. 235. Frustules with endochrome, Frontispiece, fig. CCXXXV.
2. Gomphonema constrictum, Hhr. F.V. distinctly cuneate; upper extremity rounded, lower obtuse; V. more or less constricted to- wards the upper extremity, attenuated below; striz 27 in ‘001". Length :0012" to 0024". v.v.
Kiitz. Bacill. xin. 4. Gomp. truncatum, Ehr. Inf. xviii. 1. Hass. Alg. xeviii. 2.
Gomp. pohlieforme, Ralfs, Ann. vol. xii. pl. xvii. 4. Gomp. geminatum,
Quek. H. C. xii. 4.
Fresh water: frequent. Lewes, May 1850, &c., 1”. Sm. Harrison’s Rocks, Sussex, Mr. Jenner. Lough Mourne Deposit. Peterhead Deposit. Dol- gelly Earth, &e.
Plate XXVIII. 236.
BRITISH DIATOMACE. 79
3. Gomphonema acuminatum, Hhr. fF. V. cuneate, slightly in- flated at centre, and crested at the upper extremity; V. constricted triangular and apiculate above, attenuated below ; striz 24 in -001".. Length :0011" to :0028". _ v.y.
(. V. much elongated and slightly constricted below. Length :0031" to 0042".
y- V. cuneate at larger extremity, constriction often obsolete.
Ehr. Inf. xviii. 4. Kiitz. Bacill. xiii. 3. ad specim. quee dedit amic. De Bré- bisson. Prit. Anim. xvi. 23. Hass. Alg. xcix. 1. Gomp. minutum, Ralfs, Ann. vol. xii. pl. xvii. 5.
Var. 3. Gomp. coronatum, Kitz. Bacill. xxi. 12.
Fresh water: frequent. Lewes, Nov. 1851, W.Sm. Lough Mourne and Peterhead Deposits. Var. 3. Dolgelly Earth. Rescobie, Mr. P. Grant. Var. y. Lewes, Feb. 1853, &c. W. Sm. (San Fiore, Italy. Little Falls, New York.)
Plate XXVIII. 238. a, a', & 6. Var. B. 238 B. Var. y. 238 a! & al".
4. Gomphonema cristatum, Raifs. F.V. obovate, crested; V. ob- ovate, apiculate; lower extremity acute ; stria 24 in‘001", Length 0009" to :0022". v.v.
Ralfs, Ann. vol. xii. pl. xviii. 6. Hass. Alg.c.1. Gomp. Augur, Kitz. Bacill. xxix. 74?
Fresh water. Shoreham, Kent, Dec. 1842; Farnham, Surrey, Jan. 1844, Mr. Jenner. Pond, St. James’s Park, London, Jan. 1852, Mr. Shadbolt.
Plate XXVIII. 239. Frustules with endochrome, Frontispiece, fig. CCXXXIX.
5. Gomphonema dichotomum, Kii/z. F.V. slightly cuneate, trun- cated; V. lanceolate, acute; striz 34 in ‘001". Length -0011” to 70018". v.v.
(. Stipes incrassate ; frustules flabellate, obtuse.
Ralfs, Ann. vol. xi. pl. xvii. 7. Kitz. Bacill. viii. 14. Hass. Alg. xcix. 2. Gomp. minutum, Ag. Consp. p. 34. ex specim. authen. quee communi- cavit cl. Dr. Greville. Gomp. gracile, Ehr. Inf. xvii. 3.
Fresh water. Wareham, Jan. 1850. Penzance, Mr. Ralfs. Marl, Co. Down. Premnay Peat. Var. 6. Plumpton, Sussex, Apr. 1852, W. Sm.
Plate XXVIII. 240. Var. 3. 240 8. Frustules with endochrome, Frontis- piece, fig. COXL.
80 BRITISH DIATOMACEZ.
6. Gomphonema tenellum, /V. Sm. Stipes very short; F.V. linear, truncate; V. lanceolate, extremities slightly produced; strize 30 in 001". Length 0006" to :0014". v.v.
Gomp. micropus, Kiitz. Bacill. viii. 12. ad specim. que dedit amic. De Bré- bisson. In Conjugation, Thw. Ann. vol. xx. pl. xxii. fig. D.
Fresh water. Wareham, Dorsetshire, Mar. 1848; near Lewes, Sept. 1850, W. Sm. Near Bristol, Mr. Thwaites. Wray, near Lancaster, Mr. G. Smith. Cantyre Peat. Marl, Co. Down.
Plate XXIX. 243.
7. Gomphonema capitatum, Hir. Stipes quite distinct; F.V.cu- neate; V. slightly attenuated towards the upper extremity, which isrounded ; much attenuated towards the lower, which is somewhat acute; striz 27 in°001". Length -0009" to 0014". v.v.
Ehr. Inf. xvii. 2. Kiitz. Bacill. xvi. 2. Fresh water. Lewes, May 1850, W. Sm. Plate XVIII. 237.
8. Gomphonema olivaceum, Hr. Frustules and stipes forming mucous masses; F. V. distinctly cuneate; V. slightly attenuated ; upper extremity rounded, lower acute; striz 28 in ‘001”". Length 0004" to -0018". v.v.
Ehr. Inf. xviii. 9. Kiitz. Bacill. vii. 13, 15. ad specim. quee dedit amic. De Brébisson. Echinella olivacea, Lyng. Tent. lxx. c. 1, 2, 3. Gomp. minutissimum, Grev. 8. C. F. tab. cexliv. 1. ex specim. quee communicavit cl. Auctor. Gomp. Berkeleyi, Ralfs, Ann. vol. xii. pl. xviii. 8. Hass. Alescs 2.
Fresh water: in streams, frequent in winter and spring. River Froome, Dorset, in vast quantities, Dec. 1849. River Ouse, Sussex, equally abundant, Feb. 1852. Henfield, Sussex, Mr. Jenner. Duddingston Loch, Dr. Greville, Mar. 1826.
Plate XXIX. 244.
9. Gomphonema intricatum, Kitz. F. V. almost linear, truncate ; V. lanceolate, obtuse ; strize 30 in‘001". Length -0007” to -0021". V.V.
Kitz. Bacill. ix. 4.
Fresh water: forming a velvet-like stratum on the surface of a chalk cliff. Beachy Head, Sussex, Aug. 1850, W. Sm.
Plate XXIX. 241.
BRITISH DIATOMACE. 81
10. Gomphonema Vibrio, Kir. V. almost linear, very slightly at- tenuated, obtuse ; striz 22 in ‘001". Length :0021" to-0031". v.v.
Ehr. in Kiitz. Bacill. xxix. 75.
Fresh water. Wray near Lancaster, Mr. G. Smith, Aug. 1851. Lough Mourne and Peterhead Deposits. Marl, Co. Down.
Plate XXVIII. 242.
11. Gomphonema ? curvatum, (iitz. Stipes elongated, filamentous and dichotomous; F. V. curved; V. enlarged towards the upper extremity, which is rounded and inflected, attenuated towards the lower, which is acute; nodules absent in the convex (outer) valve ; striz 30 in :001". Length :0007" to 0021". v.v.
6. Strize more distinct, 22 in ‘001".
Kiitz. Bacill. vii. 1. Gomp. minutissimum, Ehr. Inf. xvii. 5. Ralfs, Ann. vol. xii. pl. xviii. 9. Hass. Alg.c. 3. In Conj. Thw. Ann. vol. xx. pl. xxii. fig. B. Prit. Anim. xiv. 9, 10, 11,12 & 17.
Fresh water: ponds, very common. Near Belfast, Aug. 1849 ; Plumpton,
Sussex, Apr. 1852, W. Sm. Pond, St. James’s Park, Jan. 1852, Mr. Shad- bolt. Var. (3. Shoreham, Kent, Mr. Jenner, 1843.
Plate XXIX. 245.
12. Gomphonema ? marinum, /V’.Sm. Stipes incrassated, branching in an irregular manner; F. and V. as in the last species; striz 35 in 001". Length 0005" to -0021". v.v.
Gomp. curvatum, 3. marinum, Kitz. Bacill. viii. 3. Prit. Anim. xvi. 11.
Marine: frequent. Coast of Sussex, Oct. 1851, &e. In Conj. Mar. 1852, W. Sm.
Plate XXIX. 246.
The last two species are characterized by several peculiarities. The curved form of their frustules, and the want of symmetry in the valvular markings are notable circumstances, which seem to place them apart, while the inflection of the upper extremity of the valve, easily recognised upon a side view, is a feature not found in any other species of Gomphonema. The last circumstance would seem to point to Rhipidophora as their appropriate position; but the presence of a central nodule on the inner surface, and the more perfectly sili- ceous nature of the valves, forbid their union with that genus. The species are so closely allied to each other, that it becomes difficult to distinguish them by a verbal description, if we confine our attention merely to the frustules ; but the general appearance of the growing plants, arising from the characters of their stipes, is very different, and their habitats are so wide apart, that there can be no doubt of their distinctness.
G
io 9) bo
BRITISH DIATOMACE.
Genus 27. PODOSPHENIA, Ejhr.
Frustules attached, sessile, cuneate; valves convex, obovate, inflected at the larger extremity, striated, traversed by a longitudinal median line.
This genus is placed by Professor Kiitzing at the head of his second tribe, viz. Diatomee vittate. The Vitte, upon the presence of which he has constituted this division, do not seem to me to be special organs, but modifications in the outline of the valve, which in the present genus is slightly inflected at its larger extremity, causing on a front view the appearance of notches at the spot where the valves unite with the connecting membrane, and the foramina exist. The apparent prolongation of this notch to the lower extremity of the frus- tule, is nothing more than the valvular suture which is seen in all the Diatomaceze. The appearance of two notches at one extremity in the same frustule arises from the progress of self-division; for on the first formation of the new half frustules, the inflected portions of each valve are in close proximity, and but one notch and one “ vitta” can be detected. An examination of the frustules, given in Plate XXIV. figs. 225 and 229, will show the gradual progress of self-division, and the various appearances consequent thereupon. A side view of a single valve after maceration in acid, as in Pl. XXIV. 2254, shows the true form of the valve, and the outline of the inflected por- tion. We have here the first stage in a modification of the form of the valve, which, in its more complete development in Tabellaria and Grammatophora, will remind us of the binate form of many of the Desmidiez, in which the loculi of the cell are united by a narrow connecting isthmus.
The only very evident distinction between the present and succeed- ing genus, is the presence in Rhipidophora of an elongated and fre- quently dichotomous stipes; but a close examination of the frustules shows us that the distinct and even moniliform striz, so conspicuous in Podosphenia, are almost wholly wanting in our native species of Rhipidophora.
1. Podosphenia Ehrenbergii, Kiitz. F. V. truncate at the upper extremity; V. acute at both extremities; striae moniliform, 27 in 001". Length :0025" to 0055". _v.v.
BRITISH DIATOMACE&. 83 Kiitz. Bacill. ix. 13. Prit. Anim. xvi. 14. Podosphenia cuneata, Ehr. Inf. xvii. 8. Marine. Shoreham Harbour, Aug. 1850, WV. .Sm. Torbay, Mrs. Griffiths. Plate XXIV. 225.
bo
. Podosphenia ovata, n.sp. IF. V. rounded at the upper extre- mity; V. rounded at upper, and acute at lower extremity; striae moniliform, 24 in °001". Length :0033" to :0042". v.y.
Marine. Shoreham Harbour, Aug. 1850, W. Sm.
Plate XXIV. 226.
3. Podosphenia Lyngbyei, Kiitz. IF. V. truncate at upper extre- mity; V. rounded at upper, and acute at lower extremity; striz delicate, 46 in ‘001”. Length :0011" to 0033". v.y.
Kitz. Bacill. x. 1, 2. Prit. Anim. xvi. 13. Podosphenia abbreviata, Ehr. Inf, xvit. 7.
Marine. Coast of Sussex, frequent; June and Aug. 1850, W. Sin. Plate XXIV. 227.
4. Podosphenia Jurgensii, Kitz. I. V. truncate at upper extre- mity; V. rounded at upper, and acute at lower extremity; strice very faint, 48 in ‘001". Length 0025” to 0031". v.s.
Kitz. Bacill. ix. 12. Styllaria cuneata, Ag. in Grey. B. F. p. 408. ad specim. authen. quee communicavit cl. Dr. Greville.
Marine. Torbay, Mr. Ralfs. Plate XXV. 228.
5. Podosphenia gracilis, Hir. F.V. almost linear, truncate; V. scarcely siliceous; strize obscure. Length -0011" to ‘0021". v.v.
Ehr. Inf. xvii. 6. Kitz. Bacill. ix. 10. Marine. Jersey, Aug. 1852, W. Sm. Plate XXIV. 229.
Ge
84 BRITISH DIATOMACE.
GENus 28. RHIPIDOPHORA, Kitz.
Frustules stipitate, cuneate ; valves convex, obovate, inflected at larger extremity, traversed by a median line.
1. Rhipidophora paradoxa, Kiitz. Stipes dichotomous; frustules on F. V. obovate, rounded at the upper extremity; V. rounded at upper, acute at lower extremity, occasionally faintly striated. Length -0016" to 0025". v.v.
Kiitz. Bacill. x. 5. Echinella paradoxa, Lyng. Tent. Ixx. fig. E. Gompho-
nema paradoxum, Ag. Consp. p. 34. ad specim. quae communicavit cl. Dr. Greville. Ralfs, Ann. vol. xii. pl. xvii. 10.
Marine: frequent. Jersey, Aug. 1852, W. Sm. Penzance, Mr. Ralfs. Aberdeen, Dr. Dickie. Frith of Forth, Dr. Greville.
Plate XXV. 231.
2. Rhipidophora elongata, Kiitz. Stipes dichotomous; F.V. nearly linear, truncate ; V. somewhat acute ; striz obscure. Length :0032” to 0042". v.s.
Kiitz. Bacill. x. 6? Gomphonema tinctum, Ag. Consp. p. 35. ad specimina que communicavit cl. Dr. Greville.
Marine. Frith of Forth, Dr. Greville, 1849. Cromarty, Mr. Johnson. Plate RIXVE 232.
3. Rhipidophora Dalmatica, Kiitz. Stipes incrassated, irregularly branched; F.V. truncate; V. very narrow, somewhat acute; striz obscure. Length :0008” to :0016". v.v.
Kitz. Bacill. ix. 7? Marine. Hastings and Beachy Head, Sussex, July 1850, W. Sin. Plate XXV. 230.
BRITISH DIATOMACEA., 85
Genus 29. LICMOPHORA, 4g.
Frustules cuneate, stipitate; stipes incrassate, irregularly branched ; valves convex, elongated, inflected at larger extremity, and traversed by a longitudinal median line.
The frustules of the present genus differ in no essential respect from those of Rhipidophora. They are, it is true, longer and narrower, and probably less firmly siliceous; but none of these circumstances seem to be of generic importance. The separation of the genera must therefore rest upon the fan-like arrangement of the frustules, upon the summit of an incrassate and irregularly dichotomous pedicel, which occurs in Licmophora. This character is however of more im- portance than might at first view appear, as it indicates a peculiarity in the self-dividing process. In Rhipidophora paradowa and elongata, self-division is immediately followed by the separation of the half-new frustules and a dichotomy in the filamentous stipes; while in the pre- sent genus the frustules remain for some time coherent, and continue dividing and multiplying on the summit of the pedicel, which becomes elongated and incrassated at each successive repetition of the process.
A branching, or rather longitudinal rupture of the pedicel takes place at irregular intervals, and the entire plant presents us with more or less complete flabella on the summit of the branches, and imperfect flabella or single frustules irregularly scattered throughout the entire length of the pedicel. Rhipidophora Dalmatica possesses the same character to a certain extent; but the flabella are much less perfect than in the present genus, while its pedicel is oceasion- ally so abbreviated as to ally it to Podosphenia.
I have given, in accordance with the authority of my predecessors, two species of the present genus; but I am far from satisfied that they are truly distinct; and I am disposed to believe that a wider comparison of specimens will necessitate their union. The fronds of both are parasitic upon the larger marine Algz, upon Zostera marina, and upon various species of Zoophytes.
1. Licmophora splendida, Grev. F. V. nearly linear, frequently attenuate, and rounded at the upper extremity; V. imperfectly
86 BRITISH DIATOMACE.
siliceous, attenuate towards the larger extremity. Length of F. “0033” to :0078". v.s. Grev. B. F. p. 408. Echinella flabellata, Ehr. Ynf. xix.1. Prit. Anim. iv.
192. Inemophora flabellata, Kitz. Bacill. tab. xii. figs. 1, 2,3 & 4. ad sp. authen. que misit amicus De Brébisson, Jan. 1853.
Marine. Appin, Captain Carmichael, and Saltcoats, Rev. Dr. Landsborough, from specimens in Dr. Greville’s herbarium.
Plate XX VI. 233. Plate XXXII. 233.
2, Licmophora flabellata, Ag. F.V. cuneate, truncate; V. rounded at the upper extremity, nearly linear. Length of F. :0033”" to 0058". viv;
Ag. Consp. p.41. L. radians, Kitz. Bacill. xi. 4. Ewilaria fiabellata, Grev. S. C. F. pl. 289. ad specimina quze communicavit cl. Auctor.
Marine. Torbay, July 1846; Poole Bay, Sept. 1848 and Oct. 1851, W. Sm. Appin, Captain Carmichael, 1826. Torbay, Mrs. Griffiths. Sal- combe, Mr. Ralfs. Aberdeen and Larne, Dr. Dickie.
Plate XXVI. 234. Pl. XXXII. 234. Frustules with endochrome, Fron- tispiece, fig. CCX XXIV.
TO
Vy @<Zby
THE GENERA AND SPECIES DESCRIBED IN VOL. I.
The names printed in italics are synonyms.
ACHNANTHIDIUM, Kitz. flexellum, Bréb. ... ACTINOCY.CLUS «0.5. undulatus AMPHIPLEURA pellucida PIGLA Cw NGUtze veloc sigmoidea AMPHIPRORA......---
eoececree
COUMSEICtAl ese seecee Gidyma.....5...2-o00 : latestriata, Bréb.... paludosa vitrea
eoecseeeeses eee oceescseccee eeeecerceese
2 eostata hyalina
lineolata, Kiitz. ... membranacea minutissima......... ovalis
Cee sccsescce
Pe erceeeesse eoecee
2 tenera ARACHNOIDISCUS «se Ehrenbergii......... Japonicus, Prit. ... AULACOCYSTIS, Hass. pellucida, Hass. ... CAMPYLODISCUS ... Argus, Bail.......... costatus GMO OUE) Gescoccason Hodgsonii Horologium......... parvulus IRalisiigesesces.scs ce SpPItalis|sc.cceedtcss sc CERATONEIS, Ehr. ARCUS KiuUtZe, seneee Closterium, Kitz... Fasciola, Kiitz. ... gracilis, Bréb....... longissima, Kiitz...
eocecse eevee
eee eecesseee
Page
Page COCCONETS)......ccc0ve | diaphanaie...ccese- 22 Grevillliieeceese sees 22 Redicultistesceceeee = 2) Placentula ......... 2) Scutellum ......... 22 Thwaitesli ......... 21 COCCONEMA ......0. 75 Boecku, Ehyr. ...... 17 Cistulatereeceeeeee 76 cymbiforme ......... 76 lanceolatum......... 7h5) ToeIAWULI, | ooeaosenacs 76 CoSscCINODISCUS...... 22 eccentricus .......++ 23 TOVIOKOT® aaquccanucoonee 23 TAGIAGUSHecceeeeeeees 23 CTENOPHORA, Bréb. pulchella, Bréb. ... 70 CYCHOTELUANs sce: 27 ANGIQUAL rsceceraceee' 28 Kiitzingiana ...... O7/ operculatal) sc... 28 operculata 8. rect- angula, Kiitz.... 27 Rotullayesiicsccrescns 28 CYMATOPLEURA ... 36 apiculata .........++. 37 ellipiieayeecseescetass 37 Hibernica ......... 37, parallelay <osnsscevae 37 Soleaw: secheanteasess 36 CYMBELDA.c..as-ccee WW ALM Smeeconeoe ences 18 2 Arcus, Hass....... 16 cuspidata .........0.- 18 Khrenbergiiz....2-. W7/ flecella, Kiitz....... 21 Helvetica............ 18 maculata .........0- 18 reniformis, Ag...... 76 Scotieavenctsce sc sicins 18 turgida, Hass..:.... 12 Zebra, Hass...... Soo) NB DIATOMA. truncatum, Grev.... 71
erystallinum, Ag.... DIscopiea, Ebr. atmospherica, Ehv.. DoryYPHORA Amphiceros......... Boecku ECHINELLA, Lyng. flabellata, Ehy. .... geminata, Lyng.... olivacea, Lyng. paradoxa, Lyng.... EpirHEeMiA alpestris alpestris, Kitz. . ANTES peek sles faeces COMStIICt ate. ce seece ce gibba STANUATH se cccvecoves Hyndmanii longicornis Miiseullustecesceee ess ocellata proboscidea ......... rupestris SOLeXis ccc sascdoserse turgida.......eeceeees ventricosa Vertagus, Kitz. ... Westermanii Zebra EuNoTIA Arcus Amphioxys, Kiitz... Diadema diodon flexuosa, Kiitz...... ghoba, Prite w.ccases eraciliss.sscsbacdesnee granulata, Ehy. ... NTO Narccoogooooc tetraodon...........- (HALON uenondaoeaoc turgida, Ehy. ...... Westermanii, Ehy.. PAAR LOU scoosoacoc EUPODISCUS ,.....0..
ae ceeecee
eee ceererace
eeesesees
seeeecoce
eee eereecvoes
eee reereecee
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IAT OUS) onc eassacces eos GLASSUSsece-scceseese fulvus Germanicus, Kiitz. radiatus sculptus EXILARIA, Grey. capitata, Hass. fasciculata, Hass... flabellata, Grev. ... fulgens, Grev. ...... lunaris, Hass. ...... Ulna, Hass.......... FRUSTULIA, Ag. linearis, Ag. GoMPHONEMA acuminatum ampullaceum, Grev. Augur, Kitz. ...... Berkeleyi, Ralfs ... capitatum constrictum .......+. coronatum, Kitz... CLIStAbUIM sees deseeae curvatum.:........ dichotomum gracile, Khr. geminatum geminatum, Quek. . intricatum IM ALINUM ssa steele seers Micropus, Kiitz. ... minutissimum, Ehr.
ee eee cee eecee
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eseeee
eoeece
minutissimum,Grev.
minutum, Ralfs minutum, Ag. .....- olivaceum paradoxum, Ag. ... pohlieforme, Ralfs. tenellum tinctum, Ag. truncatum, Ehr. ... Vibrio GyRosigMA, Hass. Hippocampa, Hass. Himantipium, Ehr. tetraodon, Bréb. ... LICMOPHORA......... fabellataeiscccss flabellata, Kiitz. ... fulgens, Kitz..2.... splendida.........s+ radians, Kiitz. INAGVATGUIG AGS eet eisesere acrospheria, Kitz. Afstuarti, Bréb.... affinis ambigua amphirhynchus . Amphisbeena
Amphora, Ehr.
en esesee
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ee re
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INDEX.
angulata, Quek. ... angustata............ AT Cus EI: ceca ee sls attenuata, Kiitz.... Baltica, Ehr. ...... bifrons, Ehr. bINOdISteesesseeeeeees Brebissonii, Kiitz.. convexa Crassinervia cryptocephala ...... CUSPIGACHicnsteseee: dicephalass...ss--4- didyma elegans elliptica elliptica, Kiitz...... WORT, | Geadocosac rane fuloa, Ehr. ......... graba, Mbt... gibberula .......... Omactlise Wintel tess sae Hippocampus, Ehy. imequalis, Khy.
inflata interrupta, Kitz... Jenner lanceolata lanceolata, Hass... lata Brebiteesscase latiuscula, Kiitz.... Liber librilis, Ehr. macilenta, Ehr. ... major, Kitz. ...... mesolepta, Kiitz.... THINULUA esses ense es nobilis, Kitz. .....- nodosa, Ehr ODEUSA ceaseless oblonga, Kiitz...... ovalis palpebralis patulagece-cercecncoe pellucida, Ehr.
eeecece
see eeerecces
eoeccesecces
se eecerecene
Ser eeesesoee
seer cere
eeeeee
ee eereees
Phenicenteron,Khyv.
producta ...0....... punctulata ......... PUSUlay eateectes radiosa, Kiitz...... rhomboides ......... rhynchocephala ... SEMICM: san. sceeeeceees SGRIAMS)aqeeneassee eee Sigma, hr. ...... sigmoidea, Ehr. ... Spencervi, Quek.... sphzrophora splendida, Khyr...... striatula, Ehr....... Tabellaria, Kitz...
NItzscHia
PLEUROSIGMA
TUMENS .ccccceccene CUM De saseceaeceee tumida, Bréb. ...... viridis, Ehr. viridula, Ehr. .....- viridula, Kitz.
Westil cs .casdasaaead
Acicularis ....20-e+es- Amphioxys ...... nas angularis ..2..-csewes Brebissoni bilobata birostrata......... ae Closterium dubia elongata, Hass...... lanceolata
eeeeeeece
sew e cores eeeee
obtusa «.ts-seseseneee parvula plana TOVEISAscacceusecaheee scalaris...... oouesenee SIQMA....c.cscasaees sigmoidea s+. eee spathulata spectabilis tenuis Tenia vivax
eeeesocce
eeceeeeeseeeree
PINNUDARIA seceseeee
acrospheeria.......+. acuminata acuta alpina Apis, Bhr. <:ccsce Cardinalis..secsecesss Cyprinus. ......0..00. GireCtaleccsecceneeces Gistans ssscneceenenee divergens......... oes gibba gracilis mnterrupta Johnsonii lata HOH seooacoac pnoeer mesolepta ......... MObilisueceeseeeeeeee oblonga PCLESTIOA aceanaeees TAdIOSAsencesesse cater stauroneiformis ... Tabellaria viridis viridula
eee eeeeereeecee
eee eee eee eescee ee
eee eeeeeeeeneeccee
ser eeeeeeees
we eecsees
fete eee eeene
acuminatum ...... TS VENI Aa bCcoascnor
Page angulatum e....... 65 angulatum, W.Sm. 65 attenuatum ......... 68 I altieumalsccsscesee =< 66 decorum ...... ssteca? 63 delicatulum......... 64 distortum ........ 5 (y/ elongatum ......... 64 asciolay sssececssess 67 formosum ......... 63 Hippocampus ...... 68 intermedium ...... 64 NACUSENON seecsenecces 68 MGEOLAle) Seceecnessiee 67 TAYE. gooobacoo00C 67 Nubecula............ 64 OUSCUTUMEs ceees. ses 65 prolongatum ...... 67 quadratum ......... 65 FIPIOUM, <se0eeecc0s. 64 RPeclOSUmM! "<........ 63 Spenceri...... castee 68 NETIOUIS” 5. ..-525e0 66 strigosum......... 64 tenuissimum ..... 5 Oy PODOSPHENIA ..... §2 abbreviata, Ehr.... 88 cuneata, Ehr. ...... 85 Ehrenbergil......... 82 SEACH IS cersnecenaeess 83 SUEPECMSH cose. 0000: 83 Wye DYEl. onns.500055 83 OVATE iccesccescuseeas 85 RHAPHONEIS, Ehr.... 77 RHIPIDOPHORA 84 Dalmatica ......... 84 elongata, «.....002.0: 84 PatAlOKA -nscssc.00s 84 SIGMATELLA, Kiitz. Brebissonii, Kiitz.. 38 Nitzschii, Kiitz.... 38 SPHINCTOCYSTIS, Hass. librilis, Hass. ...... 36 STAUROPTERA, Ehr. 54 STAURONEIS ......... 59 DOI: Ao Sean an arene 59
INDEX.
anceps cardinalis, Witz... Crucicula......... ae dilatata STACIISe cede sdes sce linearis......... Fascas parva, Kitz. ...... Phoenicenteron pulchella punctata .......+.... salina STYLLARIA, Ag. cuneata, Ag. SURIRELLA ANGUSTA ...eeereeeee bifrons, Kiitz....... biseriata Brightwellii.-...... circumsuta, Bail.... constricta Craticula........ Begs Crumena, Bréb. ... curvula, Bréb....... elliptica, Bréb. fastuosa Gemma lata
eee reece resene
see eeercoree
ore esceee
eee reer tenee oe ri
Pe ceewesereerecees
MIMUtaeeseoneeeceene
nobilis ovalis ovata panduriformis pinata Salma, sec... Maoesnes Solea, Kitz. spiralis, Kiitz. Splendidaycccssseere- striatula subsalsa turgida......... seein SYNEDRA acicularis ......s0... acicularis, Kiitz.... equalis, Kiitz.......
sence reeceseses
Pere Corer eseeee
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seeeee
weecessoscce
Cee ecevseses
a eee ror eneee
multifasciata, Kiitz.
Areus Armoricana, Kiitz. biceps capitata constricta, Kitz... erystallina ...... eee delicatissima dissipata, Kiitz. ... fasciculata ilu Pega eoeeononcce Soi Gallioni ... PTACIIS swaseneaeenence hamata levism Koutzeeceeeeer longissima lunaris minutissima @ ORE) anooodcone acts Oxyrhynchus Oxyrhynchus, Kitz. pulchella .......2.... radians salina
scalaris, Kiitz...... Sigma, Kiitz. ...... sigmoidea, Kiitz....
Ce eeeeseveees
woeeee
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@eoreresee
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splendens, Kiitz.... superba ....+2...00. tabulata < oe src.+ess
Tergestina, Kitz... Ulna WP, BNW Scoooncae Vaucheriz ......... TRICERATIUM alternans Favus striolatum TRYBLIONELLA...... acuminata angustata............ STOCUISae sme enae eee marginata punctata Seutellum
Cee reeesorescas
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eecesseee
See eseeeeees
PRINTED BY TAYLOR AND FRANCIS,
RED LION COURT, FLEET STREET,
H
> oni
i te ri , (Pus: 7 i ° 1 ~ ‘ ‘ ' | : ‘ A ‘ + 4 1 .. ui %, ‘ee i ‘ - ‘ . . ‘ . t
Price 1s. 6d. each Slide.
MICROSCOPIC PREPARATIONS OF THE DIATOMACE.
Smita and Beck supply the following Diatomacez described in the Synopsis. As each specimen has been examined by the author of that work, the au- thority of these mountings may be relied upon by those desirous of correctly identifying these interesting and beautiful objects.
Diatomaceous Earths in Balsam.
Peterhead Deposit. Lough Island-Reavey Deposit.
Premnay Peat. Dolgelly Earth. Lough Mourne Deposit.
Cantyre Peat. Marl Co. Down.
Diatomacee in Balsam, or mounted Dry.
No. of No. of Species Species. . Epithemia turgida. 45. Triceratium alternans.
. Epithemia Westermanii. . Epithemia rupestris.
. Epithemia gibba.
. Epithemia ventricosa.
Epithemia Zebra. 47. Cyclotella Kutzingiana. Epithemia Argus. 50. Cyclotella Rotula.
. Epithemia proboscidea. 57. Surirella biseriata.
. Epithemia Sorex. 59. Surirella constricta.
. Surirella splendida. . Surirella striatula. . Surirella Gemma.
. Surirella ovalis.
15. Eunotia Arcus. 70. Surirella ovata.
18. Eunotia triodon. 71. Surirella salina.
23. Cymbella maculata. 75. ‘Tryblionella gracilis. 24. Cymbella Helvetica. 76. Tryblionella marginata. 25. Cymbella Scotica. 77. Tryblionella acuminata. 31. Coeconeis Pediculus. 78. Cymatopleura Solea. 32. Cocconeis Placentula. 80. Cymatopleura elliptica. 33. Cocconeis Thwaitesii. 81. Cymatopleura Hibernica. 34. Cocconeis Scutellum. 82. Synedra lunaris.
35. Cocconeis Grevillii. 83. Synedra biceps.
37. Coscinodiscus radiatus. 84. Synedra pulchella.
38. Coscinodiscus eccentricus. 89. Synedra radians,
41,
. Eupodiscus fulvus.
Eupodiscus crassus.
: Synedra Ulna. . Synedra tabulata.
No. of No. of Species. Species.
97. Synedra affinis. 236. Gomphonema constrictum. 102. Synedra superba. 238. Gomphonema acuminatum. 103. Synedra fulgens. 238 a!’ & al". Gomphonema acumi- 105. Nitzschia Amphioxys. natum, var. y.
108. Nitzschia Sigma. 239. Gomphonema cristatum. 109. Nitzschia obtusa. 241. Gomphonema intricatum. 110. Nitzschia linearis. 243. Gomphonema tenellum. 112. Nitzschia dubia. 244. Gomphonema olivaceum. 114. Nitzschia plana. 245. Gomphonema curvatum. 115. Nitzschia scalaris. 246. Gomphonema marimum. 124. Amphiprora alata. 247. Epithemia longicornis. 130. Navicula serians. 248. Epithemia constricta. 131. Navicula cuspidata. 250. Cymbella affinis.
134. Navicula Jennerii. 259. Surirella subsalsa.
137. Navicula elegans. 260. Surirella angusta.
138. Navicula firma. 263. Synedra hamata.
147. Navicula Amphisbeena. 265. Synedra Gallionu, & /. 147. Navicula Amphisbeena, var. 6. | 266. Nitzschia Brébissonii. 148. Navicula spherophora. 267. Nitzschia vivax.
149. Navicula ambigua. | 270. Amphiprora vitrea.
151. Navicula punctulata. |
152. Navicula elliptica. The following are mounted as Test 154. Navicula didyma. Objects.
165. Pinnularia oblonga.
168. Pinnularia alpina. | 104. Nitzschia sigmoidea.
171. Pinnularia acuta. | 118. Nitzschia lanceolata.
173. Pinnularia radiosa. 129. Navicula rhomboides. 176. Pinnularia cyprinus. 199. Pleurosigma elongatum. 178. Pinnularia stauroneiformis. 200. Pleurosigma intermedium. 185. Stauroneis Phcenicenteron. 201. Pleurosigma Nubecula. 186. Stauroneis gracilis. 202. Pleurosigma delicatulum. 194. Stauroneis pulchella. 204. Pleurosigma quadratum. 195. Pleurosigma formosum. 205. Pleurosigma angulatum. 203. Pleurosigma strigosum. 206. Pleurosigma obscurum. 207. Pleurosigma Balticun. 209. Pleurosigma acuminatum. 208. Pleurosigma strigilis. 211. Pleurosigma Fasciola. 216. Pleurosigma attenuatum. 214. Pleurosigma littorale. 219. Cocconema lanceolatum. 215. Pleurosigma Hippocampus. 221. Cocconema cistula. 216. Pleurosigma attenuatum. 222. Cocconema parvum. | 217. Pleurosigma lacustre. 223. Doryphora Boecku. | 275. Pleurosigma macrum.
235. Gomphonema geminatun.
For other Objects, Microscopes, Xe. see Catalogue.
6 COLEMAN StrREET, March 1853.
BPITHEMIA. > lst
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EPITHEMIA. EUNOTIA. CYMBELLA AMPHORA. COCCONEIS. EUPODISCUS. TRICERATIUM. CAMPYLODISCUS. SURIRELLA. TRYBLIONELLAG@YMATOPLEURA. SYNEDRA. Supp. Pl. XXX
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CATALOGUE
OF
ACHROMATIC MICROSCOPES, &c.
MANUFACTURED BY
SMITH AND BECK,
TO WHOM THE COUNCIL MEDAL OF THE GREAT EXHIBITION OF 1851 was AWARDED ‘‘ FOR THE EXCELLENCE OF THEIR MICROSCOPES,”
6, COLEMAN STREET, LONDON,
Marcu 1853.
THEIR improved form of Stand, which is contrived for an easy and most accurate mode of applying every kind of illummation, was shown by them at the Great Exhibition of 1851, and is thus mentioned by the Jury :—
“The Stand is excellent in principle; the body, stage, and appliances beneath, are all carried on one stout bar, on the recommendation of Mr. G. Jackson, by means of which the centring of the Achromatic illumination is rendered easy and certain; and on any tremor being communicated to the Instrument, it is equally distributed over the whole of the working parts.’ —(Reports of the Juries, pa. 266, Class X. No. 253.)
The increase of the Angle of Aperture, which 8. & B. have lately effected in their Object-Glasses, is more especially worthy of notice in the lower powers, which, adjusting through considerable thickness of glass, or some depth into water, will, with a large aperture, exhibit those objects which are the most frequent observation of the naturalist, with a definition that a smaller angle of aperture cannot give. One of these Object-Glasses, a #5ths (erroneously called “ half-inch” ), is thus alluded to in the “ Reports of the Juries of the Great Exhibition” (pa. 266, Class X. No. 253) :— ;
“The half-inch focus of 70° aperture is a wonderfully fine combination, easily showing objects considered difficult for a one-eighth inch focal length a little more than a year since, and bearing the application of the higher eye-pieces in an unprecedented manner.”
LONDON: PRINTED BY TAYLOR AND FRANCIS,
RED LION COURT, FLEET STREET.
nn
Prices of Stands for Achromatic Microscopes, exclusive of Object-Glasses, ae Apparatus and Cases, except where mentioned .........0..ceseceeeeeeeeeee 1 Microscope Cases, for No. 1 Instrument, No. 2, Nos. 3 & 4. .....0....000 2 Achromatic Object-Glasses for the Microscope ...........seeeseeeeeeersseees 3 Apparatus which applies to the cylindrical fitting under the stage of No. 1 or No. 2 Microscope ...........0.ss0.-2- AA Eee coco deneinoasbacteponodso0- 3 Apparatus as applied to No. 3, No. 4 and No. 5 Microscopes .............. 4 Apparatus for Microscopes in general ............seseeeses cprhigcondosescacbasoc 4 Microscope bablesmrcecesetasestessesemescses nogsocecss6ed Sacsacedsstereondecemaaete 5 Microscope MaMps) w.ssccccscesncseseccessecrsetsecscceteceeeetossnsescrsereceemen 5 MAREE OO OOYRES _ coscaodooscaccéceosedonceuasceocscoctiboaccacponessactancsaco0e: 6
Cabinets for Objects, in which the Specimens lie flat, and with Porcelain
Mabelsi tothe Dra werswes.c.sceedsceceesaecisccotdctce ence ceeeteeceeenserescre 6 Instruments used in Preparing Objects <....2./.csccsesseves-roscceracescesonnes 7 Matenalsiusedans Mounting Objectsieccsseases-e-ceneeeesoneas-neeeeceseeeeeeeees 7 Woodward’s Table and Hydro-Oxygen Polariscope and Microscope ....... 8 Books ..... ROQnAROCORBOIDAnHatODOCONSUCAnOEsbodccHadHoGabogsoSnSnoceadboosDSS¢ocaticonSC 8 TElESCOPESH, sasccas fae sacsmes pleases cawstence sehen anensunnedeme cenecmcae ete naeee soeee 8 Spectaclesiand: Bye-olasses\.s..cse<s<+sederseecsenescucnsesenesesctracsaeseenssseee 9 StGLEOSCOPES 3 sc ccdseteacssuacesssetonsesscsneseesscouseuetee csc soete ee tenseeeonere ee 10 Drawing instruments, OcColecsceces score sc sten aesees Gnaceeeecetarconan saree scents 10
Barometers; (Chermometers,, &Cic. 0. scone sscc coed canencesespecesedeacensiaaaerss 10
Exclusive of Object-Glasses, Apparatus and Cases,
PRICES OF STANDS
FOR
EXCEPT WHERE MENTIONED.
ACHROMATIC MICROSCOPES,
[The construction of all these Microscopes is now so arranged, that Smiru AND Beck can supply any apparatus without requiring the Instrument for fitting. |
No. 1. Improved large Microscope, the limb continued
under the stage, and with cylindrical fittmg and rackwork, for applying all illumimating apparatus with ease and accuracy, mounted on two pillars and cones, with revolving base to tripod; body with quick and slow motions, graduated sliding tube, and two eye-pieces; stage half inch thick, with vertical and horizontal actions (given by rack- work and screw, or lever), sliding and revolving planes, and spring clamping piece; diaphragm with revolving and removeable fittings ; large plane and coneave murors, with lengthenmg arm, and sliding on a triangular bar; pliers, jomt and for- ceps, and two glass plates ....-..s.scesseeeeeseneeeeees
. Improved large Microscope, on exactly the same con-
struction, but made very portable ..........-..s.6. 33
. Improved smaller Microscope, on the same principle,
and with the same actions as No. 1, but with single pillar, on tripod stand.....secseseesseeseeesseeeeeeeeaees
. Improved smaller Microscope, made portable ......... . Best Student’s Microscope, with uprights and jomts,
quick and slow motions to body, graduated sliding tube, and two eye-pieces; thin stage, with vertical and horizontal actions by rackwork, slidmg and revolving planes, and spring clamping piece ;_ dia- phragm with revolving and removeable fittings ; double mirror, with lengthenmg arm ; pliers, for-
ceps, and two glass plates .......-.+++5006 “Areneepanosce 12 . Best Student’s Microscope, the same as No. 3, but
with plain stage, consisting of sliding piece and clamping spring, one eye-piece, and single concave mirror ..... La radalash dee wal teein apa sroned cn ulnwodeatesceldedileeees
£
bo bo
25
18 DAI
=
Ss.
SS)
d.
0 0
2
No. 5, Smaller Student’s Microscope, with quick and slow motions to body, one eye-piece, sliding tube, stage the same as No. 4, revolving and removeable dia- phragm, single concave mirror, pliers, forceps, one glass plate, and mahogany Case .........ssseeeeeeeeeees
No. 6. Hospital Microscope, without joint, body with rack- work motion, or sliding tube and slow motion, one eye-piece, diaphragm, single mirror, and mahogany PE) noc Adbnanee sou ste cud0Be Jbor chug ogonoy joa locas acoder at
No. 7. Travelling Microscope, quick and slow motions to body, two eye-pieces, sliding tube, stage the same principle as No. 4, revolving and removeable dia- phragm, double muror, and “packed i ima Steet case 10 inches by 43 inches and 3; inches deep ..
No. 8. Dissecting Achromatic Microscope, with quick mo- tion and graduated sliding tube to body, stage the same as No. 4, revolving and removeable dia- phragm, single concave mirror, 3rds object-glass, one eye-piece, erecting glasses and case; power from 5 tol OOimearsce....c) a. Beganodeas-0903 Scannrdaqnendegnes
No. 9. Darwin’s Improved Single Microscope, with one dou- blet, three single, and three Coddington lenses, dissecting apparatus complete, and packed in a (CIE TS prt ap nasapdocdet6ca6 SoS NaGUC SCOP OE anocmasconaoenaant
MICROSCOPE CASES,
FOR NO. 1 INSTRUMENT.
Best Upright Case in Spanish mahogany, with box for ap-
PATALUS ....cereeeeeseseencecceceeeseneeeerenseseceeentesens Best Upright Case, with twODOXES | cessecccssceeescteccsiese enaniais Upright Case in Honduras mahogany, with box for appa-
Upright Case, with two boxes ....ssssssesssecceeeees seacnbncceee Strong Flat Case in Spanish mahogany, with covered dove- tails for the instrument when made portable ......
NO. 2. Best Upright Case in Spanish acer with box for appa-
ratus. nooauoonde Betcaisieisiarstereieto aicluietaisle slelewieielenye rerio Baciesieteiteieine
TALUS... 2. seereccccerececccecesccensenseesseeeesccecesentenees Strong Flat Case in Spanish mahogany, with covered dove- tails for the instrument when made portable ......
nos. 3 & 4.
Best Upright Case in Spanish mahogany, with box for SERS YAtUS .......e00ee coe eee cecccerececssssneneeeeeoeccnes seeeeeeee Upright Case in Honduras mahogany, with box for appa-
5 10
3 10
Pe
2 2 1 15
oO coo SS)
SS)
3 Achromatic Object-Glasses for the Microscope.
Linear Magnifying Power nearly*. Anipletor Lieber. fos With Eye-Pieces | @perture Price. aa aan N°.1/N°.2(N°.3] Put tional. 7 Draw-tube closed | 20 | 45 | 86 Ma sd g inch | Add for each inch 13 degrees| 3 0 0} 15s.
oftubedrawn out; 4] 6 8 5 Tube closed ...... 60 |105 | 180 3 inch | Add for each inch 27 degrees] 3 3 0} IIs. of tube....... scboa|: (tf |) ta | AD , Tube closed ...... 120 |210 | 350 {To inch | Add for each inch 55 degrees| 5 5 0} 10s. OlstUDeseeracceets: 12} 20] 35 Ditto Ditto do. | do. | do. | 65 degrees; 6 6 0) 10s. 7 Tube closed ...... 240 |430 | 720 “5 inch | Add for each inch 85 degrees| 6 6 0 Ofjuu Demereaceeene: 30 | 45 | 80 Ditto Ditto do. | do. | do. |100 degrees) 7 7 0 Tube closed ...... 450 |760 |1300 + inch | Add for each inch 100 degrees} 8 8 0 oftube..........| 40 | 60 | 115 Ditto Ditto do. | do. | do. |120 degrees 10 10 0
* With the $ inch object-glass and the erecting glasses, employing eye-pieces Nos. 1 and 2, the magnifying power will range from 5 to 150.
APPARATUS which applies to the cylindrical fitting under the stage of
No. 1 or No. 2 Microscope. oo; 'SSaad: Achromatic Condenser on an improved construction of two powers, and revolving diaphragm, to give various illuminating pencils from 80° to 25°, also stops for
the central rays, complete with adjustments ...... a 08-0 Achromatic Condenser without diaphragm, apertures 60° and
20°, brass work with adjustments ..........scscseeeeee 210° 0 Achromatic Condenser, Brasswork of, with adjustments...... 1 = 00%0
Wenham’s Parabolic Reflector, giving a dark field with an object-glass of 100° of aperture, with adjusting stop ANG fIEtINES ..2.-sceecevsesaunare eecee seoeeotenee editnanes 115 O Amici’s Prism for oblique light, mounted on an improved plan, with the reflecting surface uncovered for the convenience of wiping ......... StedchePretoncnucdcenener 2a 20
4
£s. d.
Nachet’s Prism for oblique light, with accurate revolving
TGR SF eeclae isa oes ae eterna oe alate ate oe el aeeraree ie 121 Right angle Prism for reflecting the light more perfectly than
the muror, with adjustments and fittings to the tri-
angular mirror stem complete, and the reflecting
surface uncovered for the convenience of wiping... 2 10 Polarizing Apparatus, of two Nicol’s prisms and one selenite
film, with revolving fittmgs 0 “alllll eee Senterinee siect ole ee = 2 10 Darker’s Series of Selenites, which give 13 different colours
and their complementary tints, mounted on an 1m-
proved plan for their more accurate and easy ap-
jE C SRA Ens ASCAMOnOe: Cracrt GabearoAWceat concotipukaer cs 3 10 Darker’s Series of Selenites, adapted to the Selenite fitting
mentioned in “ Polarizing Apparatus”’............ Beary wulle® 7 Bundle of Thin Glass for polarizing by reflection or trans-
MISSION sic a eaeiheniSetelenioe de dsien doasestenasewetmeaeacene tess el Black Glass for polamZing. ..4.25..40ssessseanasaaceedsesesenns devs 0 15 Dark Wells of three sizes, and holder ............csceeesceseeees 0 12
ener"
APPARATUS AS APPLIED TO No. 3, No. 4 and No. 5 Microscopes.
Achromatic Condenser of two powers, 60° and 20° of aperture, rackwork and complete adjustments to brasswork.. 3 0 Achromatic Condenser as above, with sliding fitting, and no
adjustments{0 DrASSWONK -..-+<.ondccwere rns) esecwalesls 2a Achromatic Condenser, Lenses Of .........-.sssseccssessscoeecees 1 10 Wenham’s Parabolic Reflector, with slidmg stop, rackwork,
and complete adjustments to brasswork ............ 3 17 Wenham’s Parabolic Reflector, with plain sliding fittings ... 2 10 Nachet’s Prism for oblique light ............scsscsssscseeeererees 0 18 Polarizing Apparatus, of two Nicol’s prisms with revolving
fittings, and one selenite film...............ssseceeesees 2 10 Dark Wells of three sizes, and holder .................c0eeeseees 0 12
APPARATUS FOR MICROSCOPES IN GENERAL.
Extra Eye-piece for No. 1 MichOScOpGe)-c-nece-aeeennsa eehtnecs 0 17 Extra Eye-piece for No. 2, 3,.4, or 5. Microscope .«..........:. 0 15 Extra Eye-piece for Hospital Microscope cpr ceponce fee conten 0 13 Indicator to Eye-piece ......-s:eccceesaceosentetcceseesececensoees 0 5 Micrometer, with Jackson’s adjusting screw and fittings to
Bye@=pleC@ resco: seenee+onmeseeqececeasqcceteacegecrnasder'eas 1.0 Micrometer for Stage, divided into 100ths and 1000ths of an
meh, and mounted in brass ..sssesssscesceesseseneseee 0 10 Micrometer for Stage, divided into 100ths and 1000ths of an
inch, mounted pe ere DRO BB COREE Hao ocuscutancoaee Oe
nace [or i=)
=)
ao oon i)
Co So i=) ocon
5
Wollaston’s Camera Lucida, with large field and fittimgs to HYE-PleCe.. s0seccacasccceennagcacsseccssscocsensesessecceces Erecting Glasses, with which, employing the two-thirds ‘inch Object-glass and Eye- -pieces No. | and 2, the mag-
nifying power will range from 5 to 150 linear ...... Large Bull’s-eye Lens on stand......ccccessscecssenceresesencneees Smaller Condensing Lens, with ball il socket fitting, to apply to No. 1 or No. 2 Microscope .......+....+++e0e Smaller Condensmg Lens, on stand, and complete move- MENS ccccccccessccccccccsccccsessccscreccrescssctcecsccoens Side Silver Reflector, with fittings to limb, or on a separate SUAIGL Gacoseocqnqqdnasdoodepcoosapaucnonngasssoscaobeasoparec Amici’s Prism for oblique light, mounted on a stand ....+. eee Polarizing Apparatus, of two Nicol’s prisms with revolving fittings, and one selenite film............--sseeseeceeees
Darker’s Series of Selenites, with stage and revolving fittings Fwo Double Image Prisms and Selenite Film, with fittings
to Eye-piece and brass plate with holes ............. Crystals to show rings round the optic axis and fitted to
LRVGS DISSE), won 6 sSoopeongAsonspconaeMmBeesoAAs. each from Movamrmalenes) sles staan sateen e heise escawsra ts thekesSocsaas from Brooke’s Double Nose-piece .......02...sssceecestonccenscenseners @ompressorumn cer seer ys see erates ence esbewas eb aseesesmene ceases Wenham’s Compressorium for Parabolic Reflector ............ crew elven OX os attcreacssescesacdecrastitsoasensrctveceriener et ace iDeives so ol Emr ib?s i Se aa asoremecconoccudeneocn ob iccoeeoreac secs oodsre Small Plain Live Box ....0.202..0.0..0sesrsecsersecsnasousseccecesene Large Glass Trough, with wedge and spring complete ...... Small Glass fr oughs scdulenpeidenielesiacciegisapeneevencetyslspeyss from Net on three Glags Tnbes./.5.2...2m4023-3seasrasenseras sean ssercnnee Glass Plates, with hollows and ledges...........0+-+0e+0++ from Three-pronged Forceps and Joint.........scscccssscssenssooersons Large Brass Pliers and smaller ditto...........- 0 5 O and
MICROSCOPE TABLES.
Handsome Walnut-wood Table, to revolve on carved pillar and claw, with plate-glass top, and apparatus packed im the drawers, as shown at the Exhibition
Walnut-wood Table, with improved revolving fittmg, on handsome pillar and claw, with leather top .........
Tron Table with revolving top ........2c..scsscsseosesseseescesees
MICROSCOPE LAMPS.
Improved small Camphine Lamp, with glass cap, to prevent evaporation of the spirit when Not in USE ....eeeeeee. Best Argand Lamp, with blue chimney, for burning oil ......
Gas Lamps made to order.
25
bo
—_—
—_ NOW NAIDADWDANOOCOSO
Or bo
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6 MICROSCOPIC OBJECTS.
[Persons living in the country can have series of Objects sent for selec- tion, on giving a satisfactory town-reference and paying carriage both ways. One week will be allowed for examination. |
Vegetable Preparations :— £ s. d. Recent: Cells, Cuticles, Ducts, Fibre, Membrane, Spores, Sporules, Tissues, Spiral and other Vessels, Hairs, Leaves, Petals, Fungi, Sections of Woods,
SOE seeks ere scterlotaetesatstics lente eeae cterterciot each specimen 0 1 6 Fossil: Sections of various exogenous and endogenous WOODS Aafia redteces cece dcncesonedonnes ace each section 0 1 6 Slides, with two and three sections...........- 0 3 O"and 0) 456 DesmidieverandvAl ee oe. cc.cctcoss eceesteerseescececnene each slide 0 1 6 Diatomacez :—Recent : Several hundred varieties, including species of Campylodiscus, Cocconema, Epithemia, Navicula, Surirella, Synedra, &e.— Fossil : Specimens from various localities in the British Islands, Ger- many, Italy, North America, the East and West InvdiessNewsZealandeacccsmeecesseaecenceeeenecreatte coe) OG Spicules and Gemmules of Sponges and Gorgonias ......... 0-16 Zoophytes; many ‘species’: :..c..cesceesacctsasdeeeateererennneee tees O a6 Shells, sections of various SPECIES caseercaescaneateneMecascaaecent OF IEG Echinus Spines, sections in great variety .......cccseeeceseeeeees 0: 16 Entomological Preparations : Antenne, Eyes, Feet, Hairs, Scales, Skins, Spiracles, Stings, Stomachs, Tongues, Trachee, Wings, &c. Specimens of numerous Acari and Parasites............ 0O- A 36 Hairs, Whiskers of various Animals mounted whole or in section, Quills, Feathers of Birds, &¢. ..........sseeeeee MY uo Objects from Human and other Bodies .........ss.sssseeeeenes O° EG Anatomical Preparations :— Blood-Discs, Pigment-Cells, Skin, Muscular Fibre, Tis- SUES AOCOS Niwecc swede tains sla ccdenee eee ERR Recon eaee from O 1 6 Bones :— Transverse and Vertical Sections of 60 or 70 Recent and Fossil Mammals, Birds, Reptiles, and Fishes Meche each slide 0 1 6 Transverse and Vertical Sections of about 30 varieties, Recent:andgHossil 25... ..cessecsccecnsnaccoe tenes each 0 2 O Injected *Preparutions ..cccsee.casaderesemecsedae menses eee from 0 2 6 Polariscope Objects, about 100, selected from Animal, Vege- table, and Mineral Substgnces ........sesceeeeseess each O 1 6
Mineralogical :— Sections of Limestones, Oolites, Flints, Agates, &e. each from 0 1 6
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CABINETS FOR OBJECTS, in which the Specimens lie flat, and with Porcelain Labels to the
Drawers.
Best Spanish Mahogany Cabinet, with glass panel, and to hold 1000jiobjects! 7 Acsenneannstteononsecercoesence se. 7 0 Honduras ditto, without glass panel.............scscscsseceeeees 6. (690
7
we, Sa 1d Best Spanish Mahogany Cabinet, with glass panel, and to hotdh7 oOhabyectsbenesee aec-s cancsteecuydocensoseenect ne 515 U Honduras ditto, without glass panel ........sesssseeeseseeeeeeeees on Ons0 Best Spanish Mahogany “Cabinet, with glass panel, and to Hold) SU ObyCetsiscerecscmsenesscecsadeoschotcnsinesongesmes 4. 4) ,0 Honduras ditto; without lass panel.....-.c2..scsce++4sssessseee< SP OM O Cabinets made to any size, and of every description. Cardboard Boxes, to hold two dozen objects .........++ exch, O 1 0 Ditto ditto one dozen) ditto) <..eessscesees 4, (0) O89 Ditto ditto half dozen ditto ..........2+00 0 0 6 Single Mahogany Racks, for objects .........essseeees per foot 0 0 6 Double ditto CittOvecssannussscaniencessceree a OO
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INSTRUMENTS USED IN PREPARING OBJECTS.
Wood-cutting Machine with knife ............6 Seeiisestemeisenece I Instrument for Cutting Circles of thin Glass ............000065 1s 0 Diamond for Writing or Cutting thin Glass...............20060 0-7, 6 Ditto for plate and window Glast 61890. ..2isrcsssecstele 012 0 Instrument for making Cells of gold-size or other fluids ae, “6 Page’s Wooden Forceps, for holding the glass slides when
Vip tao | oe AapondganaRSgaeadcicounes uso Lane Goasere EUoUaLEOaM 0 2 6 Small Buss Tables and Lamps for heating objects in mount-
HIVE hopabonboon seqdec asst ocbdecnopavopSesoescsnanedoaos from 010 6
Gueketts: Porceps tOmacep jars eetntet ce sen cecenecterconecte ce OO 7 6 Ironwork of Dredge, for deep-water fishing ...............+6- Ls 0 Small Collecting Bottles.................006 per doz. ls. 6d. to 0 3 O Valentine’s Knife, for making sections of soft substances... 0 15 0 Small Dissecting Knives of various shapes ..........+008 each 0 3 0 Spring Scissors, 7s. 6d.; Curved ditto, 5s.; Straight ditto, 3s. Needle Holders, 5s.; ES Hooks. 2s. 6d.; Points, 2s. 6d. Cutting Forceps, 5s. "6d. ; Spring ditto, 3s. Combination of three Lenses, mounted in Tortoiseshell, for
pocket hand! macnifiers: -.....<...coscoccsssaceosecasese 010 6 Ditto; withysmallibrassistands.ccsesnsscccecoeateeettacer otececeeeer 018 O Coddington Lenses, in various mountings ........s00.0 fromi'0 6:76
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MATERIALS USED IN MOUNTING OBJECTS.
Canada Balsam, Asphalt, Gold Size, Glycerine, &c., 1s. and 2s. bottles.
Thin Glass, in circles, 6s. per 0z.; in squares, 4s. peroz.; ditto, mixed, 5s.
Plate-glass Ships, 3 inches by | inch, with ground edges, Is. per dozen.
Glass Cells, square, round, oblong, oval, and with solid bottoms, 2s. 6d. and 3s. per dozen.
Labels for covering objects, 3s. per hundred.
8
WOODWARD’S TABLE AND HYDRO-OXYGEN POLARISCOPE AND MICROSCOPE. 3
Woodward’s Table Polariscope and Microscope, with polari- zing bundle, black glass, silvered reflector, and ground glass shade; large stage, with complete fit- tings, and two powers with rackwork motions, smaller stage for crystals; and box as stand, with complete fittmgs for apparatus .........cseseeeeeeeeeee 10
The above fitted as a Hydro-Oxygen Apparatus, with lantern, safety jet, bladders, and pressure boards; the Po- lariscope and Microscope Condensers, and an eye-
lens to adapt to the lowest power.........+.+-+ extra 15 Clock for the Movement of Lime Cylinder ........-....-++++++ 4 ime @ylinGers! te sacasecesesancseeetiocccriese-cotnaane per dozen 0 Tourmalines for the above instrument ......eseeeseeeeeees from 1 Selenite objects Or GittO: yeessccacsaceseneeeeceewasecciessee: a oO
Glass, Quartz, and other Prisms; together with all matters relating to Polarization.
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BOOKS.
Smith on the British Diatomaceze, Vol. 1............cseeeseeeees Quekett on the Microscope, 2nd Edition............sceeeeeeeees Quekett’s Lectures ‘on Histology ........0-.scsscscececsscecsoeees Woodward on Polarized Light, 2nd Edition ............02++. Wrythes on the Microscope) ....0-..is.scssceceseorerenseessnecenee Hassall’s British Freshwater Algze, 2 vols. .........seseseseeees Hassall’s Microscopic Anatomy of the Human Body ......... Microscopic Quarterly Journal ...........-...06- each number
SON NIC S'S =e
TELESCOPES.
1-foot Achromatic Telescope .....+-++ssssseeeeseeees A Btoscbanonces 1 20-inch Achromatic Telescope ......0s0..scsssesressessscsececenes 2 20-inch Achromatic Telescope, 2 drawers, leather body...... 3 20-inch Achromatic Telescope, 1 drawer, leather body ...... » 2-feet Achromatic Telescope, 3 drawers .........scseeeeereeeees 3 2-feet Achromatic Telescope, 8 drawers, portable ............ 4 2-feet Achromatic Telescope, 8 drawers, portable, on brass tripod stand, in small mahogany case .........eseeeeeeeeee 30-inch Achromatic Telescope, 3 drawers ..........seeeeeeeees 30-inch Achromatic Telescope, 3 drawers, ou brass tripod stand, in Mahogany CASE .........scoscoecssccssecnebereraeres 3-feet Achromatic Telescope ............0ssscccescscsscsescerscoees 6 3-feet Achromatic Telescope, on brass tripod stand in maho- PANY CASE 02... cccccscecsoeceneresessrercassscaecaaescaseceeabes 10 3-feet Achromatic Telescope, | terrestrial and 1 astronomical eye-piece, pillar and claw stand, and mahogany case ... 14
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33-feet Achromatic Telescope, with finder, 1 terrestrial and 4
astronomical eye-pieces, on brass pillar and claw stand,
with vertical and horizontal rack movements, and steadying-rods, in mahogany CAaS€.......sesseeeeeeeeeren eens 40 0 Ditto on improved stand ..........ccrecocessosenceecssecersecescors 42 0 Mahogany stand for ditto and bolt ......sscecscsssecesseeveecers al Universal Equatorial stand for ditto ........cesescseeeesenseneeees 30° 0 Varley’s Stand, mahogany with brass fittmgs ............+++4 12 12
Larger Telescopes, with every variety of mounting, made to order.
SPECTACLES AND EYE-GLASSES.
Gold Spectacles, double jomt ...... Spb0o0 fom 115 Oto 3 Gold Spectacles, single joint............+++ mn Ll Oro 3 Plated Spectacles?) s.c.-s-eterne--es-~aravecee aie LOMA, GoldtHolderstesccaccsectccssecosnececeossenses ES Pil Wim 5 lated! Folders) cscccsessesesscoccceerstectess a % 0)
Goldi Hiyestramies ese acec-cdsceaentaacecsees oe 0 TON ORtow 2, lated) Hy e-framen™ soccseqe<eeccessees sascer po Ole o Silver Spectacles and Folders ............ a ee OR LO.
Pearl or Tortoiseshell and Gold Hand-
ATAMNES varices ccasinceedecreccaesemenscseciece ; Ag 4a. Ontono Pearl or Tortoiseshell and Silver Hand-
AT AINIES, sean deemocieias Sees ooslceaisieeicleslce's omen end French Tortoiseshell and Silver Hand-
TrAMES woiesce ce cstessacnewe caoaee segeseeee 5 Oily oO Tortoiseshell Spectacles, double-joint .......s0...csceeeeeeseeees 0 Tortoiseshell Spectacles, single-joint ..........scesecseeseeeeeees 0 Tortoiseshell Folders.............csecceseees from 0 7 Oto O Tortoiseshell Folders, with gold bridge .........e0e.sssscseeeees 1 Tortoiseshell Eye-glasses .............ss00 from 0 3 Oto 0 Fine Blue Steel Spectacles, double-joint ..................e000es 0 Fine Blue Steel Spectacles, smgle-jomt ............ eagadeen teat 0 Common Blue Steel Spectacles .......... fom 0 5 0 Spectacles, with tinted glasses ......... .. ee OI eeO Horse-shoe Frames, with tinted glasses.. _,, i) Railway, Spectacles:-..2.-sceosceccscserssuess sh ee ®)
New Glasses to Spectacles, CONVEX see....seeeceeeeecees per par 0
New Glasses to Spectacles, concave ¢...+2......s.0008 per par 0 Double for Brazilian Pebbles.
Spectacle Cases...... Antnnonoandabadesuchoqcsdbeckinasn aASqosns: from 0
Reading Glasses of every variety ......... from “0 37 Oto 2
Opera Glasses, Race Glasses, Horizon PSHii(Sl] Olah, (oa oe Oa sancr ep Saeecaieocanaer 3 5 Wl Om 9
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STEREOSCOPES. ; ES Best Spanish Mahogany Stereoscope on improved plan, with BOL OL GINPENIIS) ep nesiceeatacesiecoessesusessseyesseeesscees 1 Satinwood Stereoscope, and Diagrams ..........ssscseceeeseseees 0 Mahogany Stereosecope, and Diagrams .........+++essessee Seeees: 0 Din Stereoscope, and Wragrams .-2....0..0.--csnscesransansaes ese 0 Photographic Viewsi@w Glass <..cssces----c0s0cen-sensseenes each 0 Dasuerreotypesi cc-scase=teneeeeces Sepeerans from. 077 “6 400 Talbotypes ......... Jenstenthaceesniuesedtorses a O42! 36) to. 0 Diagrams, &e. &e. Spanish Mahogany Box to hold 2 stereoscopes and 24 slides 2 Spanish Mahogany Box to hold 1 stereoscope and 32 slides... 2 Spanish Mahogany Box to hold two dozen slides ............ 1
CASES FOR STEREOSCOPES AND SLIDES MADE TO ORDER.
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DRAWING INSTRUMENTS, &c.
Wollaston’s Camera Lucida, mounted .... from 110 Oto 3 Drawing Instruments for school use ........... sercap ares from 0 Ditto ditto IN WAHOLATY CAKE ....0>-sccnsereronaence 1 Ditto ditto in superior case, 3 ivory rules......... 3 Ditto ditto ditto in electruM ......+000.. 3 Ditto ditto ditto ditto double-jointed 6 GAM WOMAPASSES <ocere ss. caeecsncceoseceseteecees “se sedeces from 1 12-inch Ivory Plotting Scales ............ from 0 7 6to 1 12-inch Boxwood Plotting Scales, set of 3, with offsets...... 0 Ivory Folding Rules ...........ccecesssecssceseseccsereesncees from 0 Boxwood Folding Rules. .........sssceesssecesscesecssseses err iO Plain Ebony Parallel Rules ... ..........ceceesesseeeeoseees ay ue) Plain Rolling Ebony Parallel Rules...... qauasoaccguatanaes As eO. Ivory-edged and graduated Parallel Rules .......... perinch 0
DIOL II
BAROMETERS, THERMOMETERS, &c.
Pediment Barometers ....--c-cceccescocscsccccesccsscesceses from 3 Pediment Barometer, best, with float gauge .......+sseeeeeeee 9 Wheel Barometers ........cccecsseesssscccscscscsceceveeeses from 2 Standard Thermometer .......cccccsescscesssescccecsccseces Pa 2 Negretti’s Maximum Thermometer ..-.......ecsseseeeeeeseeeeees 1 Six’s Self-registering Thermometer .......-0..cseeeseeeceeeeeeees ] Horizontal Self-registermg Thermometer..........+.eseeeeeeeee 0 Boxwood Thermometers ......scsscscscecsscecscesceeeseeees from 0 Simmons’s Hygrometer ...scccsesecsecsecsscoseseccetessecesenecnces 2
RAIN GAUGES TO ORDER.
AIR-PUMPS AND ELECTRICAL MACHINES TO ORDER.
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