I

THE ANNALS

AND

.MAGAZINE OF NATURAL HISTORY,

INCLLDIXG

ZOOLOGY, BOTANY, and GEOLOGY.

(DEINO a continuation of the ANNAI.s' fOMBINKO WITH LOUDON AND CHARLESWOKTIl's ' MAGAZINF. OF NATIRAL III.STORY.')

C 0 N D U C TED BY

CHARLES C. BABINGTON, Esq., ALA., F.R.S., F.L.S., F.G.S.,

ALBERT C. L. G. GUNTHER, M.A., M.D., Ph.D., F.R.S.,

AVILLIAM S. DALLAS, F.L.S.,

AND

WILLIAM FRANCIS, Ph.D., F.L.S.

VOL. XIX.— FOURTH SERIES.

LONDON:

PRINTED AND PUBLISHED BY TAYLOR AND FRANCIS.

SOLD BY LONGMANS, GREKN, READER, AND DYER; SIMPKIN, MARSHALL,

AND -^O. ; KENT AND CO.; \V'HITTAKER AND CO.: BAILLIHRE, PARIS:

MACLACHLAN AND STEWART, EDINBURGH :

UO')OKS, FOSTER, AND CO., DrULI.V : AND ASIfER, BERLIN.

1877.

" Omnes res crcatflp sunt divinoe sapioiitia' et pt.'tenti;v testes, divitirc felicitatis liiimnnne : ex Imruiii iisu /loiiilas Creatoris ; ex pulelwitudino sapientia Domini ; ex oeeononiia in conservatione, proportione, renoratione, potenfia majestatis elucet. Earum itaqiie indagatio ab honiinibus sibi relictis semper aestimata ; A vere eruditis et sapientibus semper exculta ; male doctis et barbaris semper inimics fuit." LiNNiBCS.

"Quel que soit le principe de la vie animale, il ne faut qu'ouvrir les yeux pour voir qu'elle est le chef-d'eeuvre de la Toute-puissance, et le but auquel se rappor- tent toutes ses operations." Bruckneu, Thioric du S'/.ifhiW Animal, Levden, 17(57.

Tlie sylvan powers

Obey our summons ; from their deepest dells

The DrvTwls eome, and throw tlieir garlands wild

And odorous branches at our feet ; the Nymphs

That press with nimble step the mountain-thyme

Aiid purple heath-flower come not empty-handed,

But scatter round ten thou.sand forms minute

Of velvet moss or lichen, torn from rock

Or rifted oak or cavern deep : the Naiads too

Quit their loved native stream, from whose smooth face

They crojj tlie lily, and each sedge and rush

That drinks the rippling tide : the frozen poles,

Wliere peril waits the bold adventurer's tread,

The burning sands of Borneo and Cayenne,

All, all to us unlock their secret stores

And pay tlieir cheerful tribute.

J. Taylor, Nonrirh, 1818.

CONTEN'IS OF \^0L. XIX.

rrorirni shries.]

M MlJKli cix.

Page

I. On Stawonema, a new Genus of Fossil Ilexactmellid Sponges, Avitli a Description of its two Species, S. Cartvii and S. lohuta. Bv

W. J. 80LLAS, B.A., F.G.S., &c. (Tlates I.-V.) '. 1

II. Ou some new (Jenera and Species of Araneidea. Bv the Rev.

(). r. Camiiuidge, -M.A., C.M.Z.S., &c. (Plates VI. & Vll.) 26

III. Notes on Foraminifera. By E. Perceval Wright, M.D., F.L.S., Professor of Botany in the University of Dublin, Secretary

of the Royal Irish Academy 40

W. On the close Relationship of Hi/dractinin, Parkeria, and Sfromatopora ; with Descriptions of new Species of the former, both hccent and Fossil. By II. J. Carter, F.R.S. &c. (Plate VIII.). . 44

V. Descriptions of twenty-five new Species of Hesperidcp. By W. C. Hewitson '. 70

A'l. Remarks on Observations by Captain Ilutton, Director of the Otago Museum, on Piripai us itova-zealamJia', with Notes ou the Structure of the Species. B\ II. N. Mo:>eley, Fellow of Exeter College, Oxford, Naturalist to the ' Challenger ' Expedition 85

^'1I. On liltojHilocera from .Japan and Shanghai, with Descriptions of new Species. By Ahtuuu G. Butler, F.L.S. &c 91

VUI. On Polyzoa from Iceland and Labrador. Bv the Rev. Thomas IIlncks, B.A., F.R.S. (Phites X. & XI.) '. t>7

Christian Gottfried Ehrenberg; Corals in the Hunterian Museum figured by Ellis and Solander ; Descriptions of new Species of PiuttUhc belonging to the (ieuus Panesfhia, bv Prof. James Wood-Ma.«on; On some Facts relating to the Nutrition of the Embryo in the Egg of the Fowl, by M. C. Dareste; On the Structure and Organization of the Polt/j)hemid(r, by Dr. C Claus; Ou the Colt/cliidee of New Zealand, by D. Sharp. . 113 120

NUMlffiR ex.

IX. On two VitreohexactiiU'llid Spongt«. I!v 11. J. CAnrEH, F.PiS. &,-. (Plate IX.) 1L>]

IV CONTENTS.

Page X. List of the Spjcies of Crustacea collected by the Rev. A. E. Eatou at Spitzber<jen in the Puuniier of 1873, vnth their Localities and Notes. By Edward J. Miers, F.L.S., F.Z.S., Assistant in the Zoological Department, British Museum 131

XL Descriptions of new Genera and Species of New-Zealand Coleoptera.— Part IV. By Francis P. Pascoe, F.L.S. &c 140

XII. Contributions to the History of the Ilydroida. Bv the Rev. Thomas IIi.xcks, B. A., F.R.S. (Plate XXL) '. 148

Xin. New and peculiar Mollusca of the Order Solrnoconchia prociu-ed in the 'Valorous' Expedition. Jiv J. Gwyn Jeffreys, LL.D., F.R.S ' 163

XIV. On the Fundamental Error of constituting Gromia the Type of Foraniiniferal Structure. By G. C. Wallich, M.D., Surgeon- Major Retired List II. M. Indian Army 158

Neic Books: The Prinia?val World of Switzerland, by Professor Heer, edited by James Heywood, F.R.S. The Geology of Eng- land and Wales, by Horace B. Woodward, F.G.S. &c 1 74

Proceedings of the Royal Society 180

On the Reproductive Apparatus of the EphemeridcB, by M. Joly ; On the Nervous Sy^^tem and Muscles of the Echinida, by M. Ij. Fredericq ; Physiological Experiments on tlie Functions of the Nervous System in the Echinida. By M. L. Fredericq ; On the Motile State of rodophryajixa, by M. E. Maupas ; On Heliv villusa, Draparnaud, by J. Gwyn Jeffreys ; On a new Species of Kaultinus, by Dr. BuUer 193 200

NUMBER CXI.

XV. Description of BdeUokUna agyreyata, a new Genus and Species of Arenaceous Foramiuifera, in which their so-caUed "Imperfora- tion " is questioned. By H. J. Carter, F.R.S. &c. (Plate XIII. figs. 1-8.) 201

XVI. On the Locality of Carpenteria hcdaniformis, with Descrip- tion of a new Species and other Foramiuifera found in antl about Tnhipora musica. By 11. J. Carter, F.R.S. &c. (Plate XIII. figs. 9-1.5) : 209

XVII. Descriptions of two new Genera and Specjes of Indian Mantidce. By Prof. J. Wood-Mason, Assistant Curator, Indian Museum, Calcutta 219

XVIII. Descriptions of new Species of Conidce and Terehridce. By Edgar A. Smith, F.Z.S., Zoological Department, British Mu- semu 222

XIX. New and peculiar Mollusca of the Patellidce and other Fami- lies of Gastropoda procured in the ' Valorous ' Expedition. By

J. Gwyn Jeffreys, LL.D., F.R.S 231

CONTENTS. V

Page

XX. Description of \ip/i(ii(/iis jiti/catitts, xar. Forclii. JJy Alois Humbert '. '. 243

XXI. IIeruiapluoditi.sm amoiijr the Paiasitic Isopoda. Ileply to Mr. Mosek'V's Iloniailcs on tlio (ronerativo Orj^'ans of the Parasitic Isopoda. Jiy J. Bui-lah, li.A., Trinity Collf|,'f, Caiuhridgo 254

XXII. Additiou.s to the Coleopterous Fauna of 'J'asnmuia. By ClIARLKS O. Wateuhouse '. 2.'50

New Books: Ostriches and ()strich-Fannin<r, by Julius de Mosen- thal, t'oiisul-Ciencral of tlie .Soutli-Africiin JJi-piiblics for France, A:c. 1^0., and James lOdnuind llartinji-, F.L.S., F.Z.S., &c. On the Foraniinifera of Barbadoes (Etuile sur les Foraminiferes de Id Barbade, kc. ), by M. Ernest Vauden Broeck, &c 2o7, 200

Proceedings of the Geological Society 200

Note on the Femoral Brushes of the Mrnttidce, by Prof. J. Wood- Mason ; On the IX'velopnient of the ^Vntenniie in tlie Pectinicurn Manfiihr, by Prof J. "\\'ood-]Mason ; On the Power possessed by certain Mites, witli or ■without Mouths, of living without Food through entire Phases of their Existence or even during their whole hives, by M. M^gnin ; Note on the NidiHcation of the Aye-Aye, by ^IM. A. Milne-Edwards and A. Grandidier ; Note on the Phenomena of Digestion and on the Structure of the Digestive Apparatus in the Pkalanf/ida, by Ft^lix Plateau ; The Gourami and its Nest; Zoology of the 'Challenger' Expedi- tion ; Bate of Growth of Corals 209 276

NUMBER CXII.

XXIII. On the Distribution of Birds in North Eussia. I. On the Distribution of Birds on the Lower Petchora, in North-east Russia.

By J. A. IIarvie Brown, F.Z.S 277

XXIV. Description of some Sponges obtained during a Cruise of the Steam-Yacht ' Argo ' in the Caribbean and neighbouring Seas.

By Thomas IIiggin, F.L.S. (Plate XIV.) 291

XXV. On the Strufture of the Lower Jaw in Hhizodopsis and Jihizodus. By R. 11. Traquair, M.D., F.G.S., F.R.S.E., Keeper of the Natural-History Collections in the Museum of Science and Art, Edinburgh 299

XXVI. Description of a new Form of Op/u'nn'da- from New Zea- land. By Edg.\ii a. Smith, F.Z.S., Zoological Department, British Museum.* (Plate XV.) 305

XXVII. The Vafes AshmnUanus; of Westwood, the Type of a new Genus of Mantidce. By Prof. J. "Wood-Mason .* 308

XXMII. Hermaphroditism in the Parasitic Isopoda. Further Ilemarks on Mr. BuUar's Papers on the above subject. By H. N. MosF.LKY, Fellow of Exeter College, Oxford 310

VI CONTENTS.

Page

XXIX. Descriptions of thi'ee Ilomopterous Insects in the Collec- tion of the British Museum. Bv Autuur Gardineu Butlkr, F.L.S 311

XXX. Notice of a Barbel from the Buffalo River, British CafFraria.

By Dr. A. GvtsTUf.r, F.U.S 312

XXXI. Descriptions of some new Species of Reptiles from Mada- gascar. Bv Dr. Albert GtrNTiiKR, F.R.S., Keeper of the Zoolo- gical Department, British Museum. (Piute XVI. ) 313

XXXI I. New and peculiar Mollusca of the EiiUmida and other Families of Gastropoda, as well as of the Pteropoda, procured in the

' Valorous ' Expedition. By J. Gwyx Jeffreys, LL.D., F.R.S. .. 317

XXXIII. Notes on New-Zealand Ichthyology. By James Hec- tor, F.R.S., C.M.Z.S 339

XXXIV. Observations on the Coccosphcre. By G. C. Wallich, M.D., Surgeon-Major Retired List II.M. Indian Armv. (Plate XVII.) . . . : ' 342

On AnguiUtiJa intesfitmlis, a new Nematoid worm, found by Dr. Normand in subjects attacked by DiaiThcea of Cochin China, by M. Bavay ; On Filaria ha'matica, by MM. 0. Galeb and P. Pourquier ; On the Intimate Phenomena of Fecundation, by M. II. P'ol ; On the Vitality of certain Land MoUusks, by Robt. E. C. Stearns \ 350—355

NUMBER CXIII.

XXXV. Malacological Notes. By Robert Garner, F.L.S. &c. 357

XXXVI. On the Final Stage in the Development of the Organs of Flight in the Homomorphic lusecta. By I'rof. J. "VVood-Mason, Deputy Superintendent of the Imperial Museum, Calcutta 380

XXXVII. Note on the " Tubulations Sableuses " of the Etage BruxeUien in the Environs of Brussels. By II. J. Carter, F,R.S.

&c. (Plate XMII.) 382

XXX"V^II. Revision of the Lepidopterous Genus C7m, with De- scriptions of the new Species. By Arthur G. Butler, F.L.S. &c. 393

XXXIX. On the JEluteridce of New Zealand. By D. Suarp 396

XL. Description of three new Species of Lizards from Islands of Torres Straits. By Dr. A. Gunther. 413

XLI. Notes on Stony Corals in the Collection of the British Museum. By Dr. F. BrDggemann 415

XLII. Description of a new Species of Porttmid(c from the Bay of Bengal. By Prof. J. Wood-Mason, Deputy Superintendent of the Indian Museum, Calcutta 422

XLIII. New Coleopterous Insects from Queensland. By Charles O. Waterhouse 423

CONTKNTS. Vll

.\ru- Boo/; : ~An]\ui\l Ikcporl ol the L nitcd-St iti-s CieiiItii.'ioal ami (leojrraiiliical Survry of'lho Territories, enibracintr Colorado and parts of adjacent Territories, being a Keport of l'ro<jfre.s3 of the Exploration for the year 1874, by F. V. Ilayden, United-States Geolofri.Ht 425

Zooloiry of the ' Challenprer' Kxpedition, l)y 1'. Marl in Duncan, F.K.S., Pres. (leol. Soc. ; On tlie Modifications undergone by the Ovum of the I'hanerocarpal Mcdunff before I'ecundation, by M. A. Giard ; Note on 1'rrtif/o Mouliimana, Dupuy, by J. (iwyn Jeffreys. F.R.S. ; Sponj.'-es dredjjred up on board II.M.S. 'Porcupine'" in 18(iO-70, by II. J. Carter, F.R.S. &c. ; On the first Phenomena of the Development of Echinua viiliaris, by M. A. Giard : the late John Leckenby, Esq., F.G.S., F.L.S. 429— 43(3

NUMBER CXIV.

XLIV. On the ^'ariabilitv of the Species in the case of certain Fishes. By Dr. V. Fatio " 437

XLV. Descriptions of several African and Australian Lepidoptera in the Collection of the British Museum. By Arthur G. Butler, F.L.S., F.Z.S., &c ' 458

XLVI. On Ascodicti/on, a new Provisional and Anomalous Genus of Palieozoic Fossils. Bv H. Alleyne Nicholson. M.D., D.Sc, F.R.S.E., and R. Ethkridge, Jun., F.G.S. (Plate XIX.) 463

XLVII. On the Elateridce of New Zealand. By D. Sharp 409

XLVIII. Description of a new Species of Phasmid^ from the Malay Peninsula. By Prof J. AVood-Masox, Deputy Superinten- dent, Indian Museum, Calcutta 487

XLIX. Diag^noses of new Species of Pleurotomida in the British Museum. By Edgar A. Smith, Zoological Department 488

L. On Ruperiia xtahilis, a new Ses.sile Foraminifer from the North Atlantic. Bv G. C. Wallich. M.D., Surgeon-Major Retired List, H.M. Indian'Ai-my. (Plate XX.) ". 501

Netc Booh : The Ancient Life-History of the Earth. By Prof. H.

A. Nicholson, M.D., D.Sc, &c. . . ." *. 605

Zoology of the * Challenger ' E.xpedition, by P. Martin Duncan, F.R.S. , Pres. Geol. Soc. ; On a Newt from the Darjiling Hills, by Prof. J. Wood-Mason ; On the Value of certain Argu- ments of Transfoi-mism derived from the Evolution of the Den- tary Follicles in the Ruminants, by M. V. Pietkiewicz . . 506 510

lude.x 012

PLATES IN VOL. XIX. Plate L"|

II. I

IIL ^Structure of Staurouema.

IV. I

iV.J

VL|

Yp^ f New Genera and Species of Araneidea.

VIIL Structure of Plydractiuia, Parkeria, and Stromatopora. IX. Eurete farreopsis ; Myliusia Grayi.

■^j' f New Polyzoa from Iceland and Labrador.

XU. New Hydroida.

XIII. Bdelloidina aggregata New species of Carpenteria.

XIV. New Sponges.

XV. Ophiopteris antipoduni.

XVI. New Eeptiles from ]\Iadagascar.

XVII. Structure of the Coccosphere.

XVIII. Broeckia bruxellensis.

XIX. New Genus and Species of Paloeozoic Fossils.

XX. Rupertia Ptabilis.

THE ANNALS MAGAZINE OF NATURAL HISTORY,

[FOURTH SERIES.]

" per litora spargite muscnra.

Naiades, ct circhm vitrros consitlito fontcs: Pollice virgineo tencroB hio carpito flores: Floribus ct pictum, divsB, replete canistriim. At V08, o NyiBpliae Cniteriiles, ite sub umlas Ite, rec-urvato variata corallia trunco Vellite niusoosig e rnpibus, et milii eonohas Perte, Dea> peliigi, et pingui conchylia sueeo."

N.Partheiiii Gianneftatii Kol. 1,

No. 109. JANUARY 1877.

I. On Stauronema, a new Genus of Fossil IlexactineJlid Sponges^ with a Description of its tico Species, S. Carter! and 8. loLata. By W. J. Sollas, B.A., F.G.S., &c.

[Plates I.-V.]

Oscar Scii^riDT's remark, " Die Beliandlung der fossilen Schwiimme durch die Geognosten und Paliiontologen ist eine grausliche," has the merit of being strictly true, though in tairness it ought to be added that the geologists and palaeon- tologists are not wholly to blame for this treatment, since most of their work was done before Schmidt's books had been written, before the Hexactinellidaj and LithistidjB (which would have thrown light on their labours) had been discovered, and at a time, one may add, when the sponges in general were the outcasts of the animal kingdom.

To understand aright the fossil sponges, one must obtain a thorough knowledge first of the minute structure of these bodies tlicmselves, and next of the structure and classification of existing forms. Tlie older observers were without the means of acquiring either of these essentials ; they conse- quently, in their attempts at a classification of fossil sponges, were compelled to fall back upon external characters alone, with the addition of what internal features might chance to be revealed by a happy fracture ; and since, as we now know, different genera of sponges may assume the same form, and diverse forms may belong to the same genus or even to the

Ann. (Us Mag. N. Hist. Ser. 4. Vol. xix. 1

2 Mr. AY. J. Sollas on Stauronema, a new

same species, it is easy to see how " dreadful " (gi-ausliclie) the treatment must inevitably be which proceeds upon such a basis.

At the present day, however, things are far otherwise Avith the palaeontologists ; the microscope and the lapidary's lathe will give us most of the details we require to know concern- ing the structure of the fossil forms ; and as regards the recent ones, we are licre still better off since tlie researches of Carter and O. Schmidt have given us a scientific knowledge of the organization of a vast number of species, and a good working classification of these into orders, families, and genera. The key to the fossil sponges has thus been placed in the hands of the paleontologist ; and if he dpes not henceforth make good use of it, he will fully deserve the censure which Schmidt has passed so severely upon his predecessors.

In consequence of the assistance and advice which I have received from my friend ]\Ir. Carter, I have been encouraged for some time past to work out the alliances of some of the commoner fossil sponges ; and, as a result, I am now able to state that Siphonia pyriformis and costata possess the struc- ture of a Lithistid sponge, and are closely related to the ex- isting species Discodermia pohjdiscus (Bocage) [Dactylocali/w, Bowerbank), tliat Stromatopora concentrica and some other species of this genus show no affinities to the Foraminifera, but are Vitreohexactinellid sponges closely resembling Dacty- localyx pximicetis (Stutchbury), and that Manon macropora and a sponge called Clienendopora in the Cambridge Museum belong to the Holorhaphidota (Carter), or sponges whose skeleton consists of acerate spicula closely bound together into a fibrous network. These results, which have been fully confirmed by Mr. Carter *, I hope to publish in full in the course of a few months ; while in this paper I shall confine myself to an account of a new genus of the Vitreohexactinel- lidaj occuiTJng in the fossil state in the Gault of Folkestone.

In examining a collection of various fossils brought by' Mr. Jukes-Browne from Folkestone, to illustrate his paper on the Cambridge Upper Greensand, I was much struck with some curious forms, which were said to be Ventriculitce split into halves down the middle ; the regularity of the edges, however (which in such a case should have been broken ones), seemed to preclude such an idea, and rather suggested that the forms in question were in a complete state. I wrote therefore to the Folkestone collector, Mr. John Griffiths, re-

* Except •w'ith regard to S. concentrica ; Mr. Carter has shown that some Stromatnpnrrp are allied to Hydractinia.

Genus of Fossil Ilexactinelltd Sponges. 3

questing him to make me a collection of tlie.se fossils; and from liis successful search I am now in possession of some forty or fifty specimens, of which some five or six are in a perfect state of |)reservation, while all exhibit the halfcup- shape form whieh 1 had noticed previously.

Outward Form (PI. I. figs. 1-8). The sj)ongc is verti- cally and simply fan-shaped, compressed, single, sessile, and adherent. In size it varies from 3 inches to -2- of an inch in height, from 2 inches to f of an inch in breadth, and from 1 inch to f of an inch in thickness. The object on which the sponge grew is generally a small fragment of coprolite (PI. 1. fig. 6, h)y which in good s])ecimens still remains adherent at or near the ])oint from whieh the sides of the fan diverge. This point indicates, then, tiie " base" of our sponge ; and it follows that the diverging sides of the fan are the " lateral " edges, and the curved side which joins them, sub- tending the angle at the point below, is the " distal " or upper margin. The sponge is curved from side to side, the lateral margins being slightly approximated, so as to make the fan concave from side to side like a half-cup or hollow half-cone. The concave is the " anterior " or " interior," and the convex the " outer" or " posterior " surface.

General Structure. The sponge is composed of two obvi- ous parts a thin plate in front (PI. I. fig. 1, o), and a thick protuberant mass behind (ibid, j)) I ^ distinct seam (s), which may be merely a line produced by the approxima- tion of the skeletons of the two, or which may be deepened into a shallow groove, defines these two parts from one another along the lateral edges : on the posterior surface the distinc- tion is manifest by the free projection of the anterior plate beyond and above the posterior protuberance (PI. 1. fig. 2, o) ; and in fractured specimens the distinction is seen to be con- tinued within (PI. II. figs. 1, 2), the two structures, however closely apposed, seldom if ever merging into one another.

Anterior Plate. The surface of this is even and smooth, its thickness from back to front tolerably uniform, but slightly increasing as it grows upwards from the base ; in a specimen 2| inciies high by 2 inches broad and \ inch thick it measures 4^ of an inch at the summit, and at the base a little less than half this amount. The ratio of the thickness of the plate to the other dimensions of the fossil varies widely with difierent specimens.

The plate projects freely above the posterior protuberance, and terminates in a broken distal edge. This is the case with all my specimens. The anterior plate has been broken off, either down to the level of the posterior mass or at a short

1*

4 Ml . \V. J. Sollas on Stauronema, a new

distance above it, the maximum distance I liiive measured being \ inch.

As, then, the normal distal margin has not been seen in a single specimen, one is unable to say how much further it originally extended : it may have terminated close to its present level, though, from the abrupt way in which it is fractured, it more probably reached some distance above ; or it may have been continued into a large flabelliform expansion, thinning away above and many times larger in area than the portion now remaining in which case this plate would be the really essential sponge, and our fossil merely its base overgrown with the posterior mass ; and the probability of this "view derives support from the fact that I have in my possession a thin plate of fossil sponge (PI. I. fig. 9),

5 inches long by 4 broad, and from -i- to -V inch thick, curved from side to side, and exhibiting, as we shall see presently, every structural peculiarity to be found in the an- terior plate of our fossil. Whether this is really a continua- tion of the anterior plate can only be demonstrated by finding a specimen in which the latter actually passes into such a flabelliform expansion ; and for such a one I have directed Mr. Griffiths, of Folkestone, to make a search.

The front face of the anterior plate is a plain surface as far as the level of the posterior protuberance ; but beyond this, Avhere it begins to project freely, it is marked by a number of round, or more usually oval, oscular pits arranged quincun- cially (PI. I. fig. 1), and on the whole constant in size and distance from one another in the same specimen, but differing in both these respects in different specimens (PI. I. figs. 1 & 3). The variations in size may all be comprised between the extremes of V-o ^^d -^ inch for the length of the major axis of the ellipse.

The posterior face is of course covered below by the posterior mass ; but above, where it is exposed, it generally exhibits & number of oval spaces arranged quincuncially and closely re- sembling the oscular pits in front (PI. I. figs. 2 & 8), a little less regularity in arrangement and a thickening of the intervening structure into irregular ridges in the case of the posterior markings constituting the only difference, and that not a constant one, between the two. Sometimes the free posterior face is smooth, like the lower part of the anterior face.

When the anterior plate is broken across, one may see the oscules of its anterior face prolonged into cylindrical tubes, which pass inwards normal to the surface, and, receiving irre- gular lateral canals in their course, terminate in the oval spaces

Genus of Fossil Hexactinellid Sponyes, 5

which mark, as we have seen, the posterior face, and which probably served as the special pore-areas of the sponge, riiis arrangement accords with the general rule, that in all cup-shaped and curved fan-shaped sponges the oscules arc placed on the interior surface of the cup or on the concave Hurt'ace of the fan, while the pore-areas occupy the outer or convex surface in each case.

The restriction of the oscules to the free part of the anterior plate is only to be seen in tolerably perfect specimens ; in those which are at all worn or much weathered the oscules are exposed all over the anterior surface, and by no means con- fined to its freely projecting part. The absence in this case of the smooth face below, and the appearance of oscular mark- ings in its stead, is evidently the result of attrition, and sug- gests that beneath the smooth surface of unworn specimens the oscules may still exist, but concealed by a superficial coating: a slight examination will set tliis beyond doubt. In some instances a small patch of the outer coating has been completely worn away, while the rest of it has simply been mucii diminished in thickness ; we then see the oscules freely exposed over the denuded area, and dimly to be discerned througlx the thin coating which remains : in perfect specimens the smooth surface may be removed by dissolving the calca- reous matrix of the fossil with acid, and brushing away the superficial network which remains behind ; the oscules are then clearly revealed ; while, finally, if a section be made across the plate, the tubes which lead directly away from the oscules will be seen traversing it at right angles to the exte- rior coating (PI. I. fig. 2, e', and PI. II. fig. 1, o, fig. 2, o).

The anterior plate thus possesses the same essential struc- ture throughout ; it is a thin plate perforated completely by a number of parallel cylindrical tubes or excurrent canals, which traverse it at right angles and terminate in front in oscular pits, and behind in pore-areas. Its projection past the poste- rior protuberance shows that it is the first formed of the two structures ; and it would appear that as it extended itself ver- tically and laterally the posterior mass followed after it for some distance as an aftergrowth, while at the same time a superficial covering coated it correspondingly in front, conceal- ing the oscules beneath, perhaps converting them into pore- areas, and leaving patent those only on the projecting part above.

Posterior Mass. The posterior part forms a compact mass (PI. I. figs. 2, 4, 6, 7, 8, PI. II. figs. I & 2), which, unlike the oscular plate, rapidly increases in thickness from below upwards and from its edges to the middle of its face ; so

6 Mr. W. J. SoUas on Stanronema, a neio

that in a specimen 1^ inch high, with an oscular plate uni- formly i inch in thickness throughout, it has increased from a mere trifle at the base and the edges to i inch at the top and through the middle of its face. In contrast also with the uniform character of the oscular plate is the irregularity of growth manifest in this portion : in one class of forms it increases in a series of bulgiiigs, Avhich form g-ently rounded swellings concentric with the distal margin, or rounded ridges so regular as to give the hinder surface a corded appearance ; sometimes the gentle swellings are not continuous but sink laterally into faint dimples ; while the ridges are not always semicircular, but occasionally change their coiu'se abruptly so as to be V-shaped at one side.

Above, the upper surface of the posterior mass may be gently rounded against the oscular plate, or it may form a flat table and join the plate at right angles.

Underlying the variations in this class of forms there is, how- ever, a certain degree of regularity ; in all the posterior mass extends laterally as far as the oscular plate, and the two are conterminous along the lateral edges, whilst above, whether it joins the oscular plate gradually or abruptly, it always follows the general curve of the latter in a simple or nearly simple line. But in another class of forms, which, I think, constitute a separate species, the irregularities are much greater than the foregoing ; in them the posterior mass is seldom ridged concentrically, but soon after leaving the base it becomes lobed vertically into two or more diverging processes, differing in size and shape, and exposing the oscular plate in the angle between them : in these forms the posterior mass reaches the lateral margins of the sponge near the base only, and soon ceasing to do so as it ascends, allows the anterior plate to extend freely beyond it in a lateral as well as in a vertical direction.

Externally the porous mass presents a plain surface, never excavated by oval pits or specialized pore-areas. In section it exhibits a number of canals, which, passing from the interior in a more or less wandering course, and without any regular arrangement, terminate at length against the attached face of the oscular plate, into the excurrent canals of which they in some cases directly open ; but whether they do so always seems to me doubtful.

Minute Structure. To investigate this the fossil may be prepared in two ways : it may either be treated with some acid (I prefer nitric) by which the matrix of calcite is readily dissolved, while a siliceous network is, in well preserved spe- cim.ens, left in relief ; or slices may be cut from it and ground down till thin enough to be transparent ; this is the method

Genus of Fossil HexactinelUd Sponges. 7

to which I have chiefly trusted, only using the former when the hitter has not been avaiUible. The sections I have iiad made have been taken along the following planes : (1) longi- tudinal and at right angles to the surface, both through the centre and nearer the sides longitudinal sections (1*1. II. fig. 2) ; (2) transverse and at right angles to the surface transverse sections (PI. II. tig. 1) ; (3) parallel to the sur- face, one through the oscular plate and another through the posterior mass parallel sections (PI. II. fig. 1,6, c, fig. 3).

The aj)pcarances of these sections under the microscope I shall now describe, and in so doing shall confine myself first to an account of the skeletal structure which they demonstrate, referrinir most of the facts which bear on the mineral charac- ters to a subsequent paragrapii.

Each of the sections we have defined shows a regular net- work of fibres arranged in the following manner. Selecting a single node in the net we observe four fibres, usually sili- ceous, radiating from it at right angles to one another in the form of a cross (figs. 1, 2, 3) ; each is perfectly continuous

Fi?l.

Fie:. 2.

§10

ftc^

Sections taken throup^h the oscular plate of Stauronema Carteri, from the specimen represented in transverse section on Plate II. fig. 1 ; all magnified 30 diameters. Fig. 1. Longitudinal section {a, PI. II. fig. I). Fig. 2. Transverse section (PI. II. fig. 1). Fig. 3. ParaUel section (c, PI. 11. fig. 1).

with similar fibre from an adjacent node, and has at its greatest distance from the two nodes it connects (^'. e. at a point midway between the two) a diameter of -pi-o to -pg-ix o*' an inch ; but on approaching the node it thickens considerably BO as to fill up the angles of the cross and round them off : in this way the meshes of the net, which, from the disposition of the nodes, would otherwise be rectangular, are always round or oval ; and these rounded spaces, which are bounded by the outer margins of the fibres, are so sharply defined as to enable us to state w^ith certainty that the fibres themselves are per- fectly smooth and not in any way spined.

8 Mr. W. J. Sollas on Stauronema, a npw

In the centre of the node is a small and very definite circle, ^^ to -5^-i-T5 inch in diameter (figs. 1, 2, 3, c), which is produced by the section crossing at right angles a cylindrical tube, originally hollow, but now generally tilled with carbonate of lime ; and from this radiate four similar cylindrical canals, one in the axis of each arm of the cross ; these, of course, are seen sideways and not end on, and ordinarily they arc continuous from one node to another, like the tibre in which they are excavated. As these appearances are to be seen equally in each of three sections taken at right angles to each other (figs. 1, 2, 3), it is,clear that our quadrilateral cross of fibre is really a sexradiate one (fig. 4), with its arms arranged about three

Fier. 4.

-6

Diagram of the network of Statironema. Scale 60 : 1. a, sexradiate canal ; h, sexradiate fibre.

axes at right angles to each other, and that corresponding with the axes interiorly is a similar sexradiate hollow canal.

Kow this structure is exactly that which characterizes the , rete of the Vitreohexactinellida, and may be seen to perfection, with differences merely as to detail, in deciduous skeletons of Farrea and Aphrocallistes. In these genera, as in the Vitreo- hexactinellidee generally, the skeleton is produced by a growth of siliceous matter over sexradiate spicules ; and in Farrea occa each node of the resulting network is a rectangular sexradiate cross of fibre, which has formed about a sexradiate spicule, which thus comes to occupy the centre of the fibre. In many vitreous hexactinellids the fundamental spicule is preserved imbedded in the siHceous fibre, which is thus originally solid ; and which, as it is composed of the same material all through, without any difference of refractive index, cannot be distin-

Genus of Fossil Htxactlncllid Sjjonges. 9

guidhed into spicule and fibre, but appears homogeneou.s tliruughout. But in deciduous s[)cc[m(ins of Ap/irocallisles and Furred the original spicule undergoes a process of absorption and disappears, leaving in its place a hollow sexradiate cavity readily observable in the interior ot" tiie fibre. Our sexradiate iil)re has, then, in the fossil condition a structure essentially iilentieal with that of the recent skeleton of Farrea when in a deciduous state. The siliceous fibre of our fossil corresponds with the siliceous fibre of Farrea ; and the sexradiate canals in its interior correspond with the hollow casts of the spicules in the latter : the only difierencc is that the canals in our fossil are continuous from one node to another, while in recent Ilexaetinellida; they terminate blindly, as casts of s[)icules naturally would, their blintl terminations generally overlap- ping one another *. But even this difference vanishes with a close examination of the fossil fibre, as I shall show when we come to s])cak of the various modes of its fossilization.

The characters of the sponge already described are sufficient to define the genus, which 1 now propose to call " Stauronema,^^ from the cross-like disposition of the thick skeletal fibres about the nodes of the network, a featin-e readily visible under a common hand-lens. In the oscular plate the nodes of the network are usually arranged symmetrically at equal distances from each other, so as to form meshes which would be cubical but for the thickening of the fibre towards the node, which converts the cubes into spheres or ellipsoids. By reason of the symmetrical grouping of the nodes, the skeletal fibres fall into three series : one longitudinal, ascending from the base ; a second horizontal, radiating from the imaginary axis on Avhich the half-cone of the sponge may be supposed to be described ; and a third horiicontal and concentric "with the curve of the fan.

The longitudinal fibres (PI. II. fig. 4, /) deviate from a parallel course by diverging, as they rise from the base, towards the anterior and posterior faces of the plate ; and to maintain the uniform size of the meshes, fresh sexradiate elements are interposed in the same way as I have described in Eubrochus and the Ventriculites f. The radiating fibres, since the curve of the fan is gentle and the oscular plate thin, lie in almost parallel lines ; but both they and the concentric

[As the absorption poes on, the form of the spicules becomes lost, and that which remains is a pimple cylindrical cavity, -which led Bower- bank to say that the fibre oi Farrea was channelled like that of the Cera- tilia, ex. gr. Lit f aria. Note hj Mr. Cartkh.]

t Quart. Journ. Geol. See, Feb, 1673, p. 66, fig. 4 ; Geol. Mag., Sept. 1876.

10 Mr. W. J. SoUas on Stauronemaj a new

fibres are not, strictly speaking, confined to horizontal planes ; for they curve upwards in gentle arcs so as to suggest that they once bounded and corresponded with the rounded edge which in all probability terminated the distal margin of the plate, in the same way as a similar edge now limits its lateral margins. The oscules and excurrent canals arc arranged so regularly in the plate that they do not disturb the regularity of the fore- going arrangement to any great extent, though in their imme- diate neighbourhood the sexradiate nodes become grouped round the excurrent canal, so as to be subordinate to it rather than to the general structure ; thus some of the nodal crosses are turned round 45° out of their normal position, so as, in joining with the others, to surround the circular canal with continuous concentric fibres ; and, at the same time, the fibres actually forming the walls of the canal are both bent and thickened in order to bring about their complete adaptation to its circumference. These facts may be seen in sections, but better perhaps by etching the oscular surface with acid, when, on the solution of the matrix, the oscular network stands freely out in relief, and with its slightly expanded termination resembles in miniature the mouth of a waste-paper basket ; one can then see, by looking down into it, by reflected light, the adaptation in the arrangement of the nodes and the bending and thickening of the fibre, from which results a circular net- work with circular fibres forming the walls. One will also discover that the oscular fibres are beset with rather short conical spines (PI. III. fig. 1), which sometimes are simply spinous outgrowths, but frequently also the sixth arm of a nodal radiation, which, instead of passing into the network as usual, points freely into the excurrent canal, just as happens in the canals of Ajyhrocallistes. In direction they usually incline outwards and towards the centre of the excurrent canal, but not always ; in exceptional cases they are turned inwards, and then seem to be related to the fine canals which open in the meshes of the oscular network, since they spring from the sides of the fibre about such a space, and point into the excur- rent canal. With this modification the rule here, then, as in Ajyhrocalh'stes, seems to be that the spines always point in the same direction as the outflowing current which at one time passed by them. It is possible that this arrangement indicates a defensive function for these spines ; but, as an explanation of their position, one may recur to the fact that Carter has traced the development of the spicule from its mother cell *, and

Ann. & Mag. Nat. Hist. 1874, vol, xiv. p. 97, pi. x. ; 1875, vol. xvi. p. 11.

Genus of Fossil HexactinelUd Sj)on</es. 11

shows that the sexradiate forms arc in all probability produced by a radiate growth from the first of the six arms from a common centre : this Ixiing so, one can readily see that if the growth of a free radius took place, in the course of the excur- rcnt i-anal, it would be sul)ject to a pressure in two directions at right angles to each other one due to its growth onwards, normal to the surface from wiiich it springs, and the other parallel to the axis in the direction of the current ; and its ultimate ))osition would be the resultant of these two, and Would be in just such a jiosition as the s|)ines, in fact, assume.

The growth of the spicule from a mother cell also explains in part many other matters which would otherwise be enig- matical. Thus the wonderful regularity of the network we have previously described may be looked upon as having resulted from a mother cell which originally gave oft" buds, one at the end of each of its spicular rays /. e. in the direction of most active growth ; the cells so budded oft' would become in turn mothers, and repeat the process, till, by reason of the limita- tions imposed by the limits of the organism, they would be unable to produce more than onebud each, and that vertically except that wlien the distance between two cells became much greater laterally than twice the length of a spicular ray, a fresh cell would thus appear at the side of one of them, and the vacant place be tilled up.

Detached Oscular Plate. The thin plate of sponge-struc- ture mentioned on p. 4 is bounded on all sides but one by a broken edge; the edge which is not broken is one of the lateral margins, neatly rounded off in the same way as are the sides of the oscular plate in Stauronema (PI. I, fig. 9, n n n). Anteriorly the plate is marked by oscular pits (fig. 9, a) quincuncially arranged, and of the same shape, size, and distance from one another as in Stauronema. These pits are the mouths of cylindrical excurrent canals, which perforate the plate and open posteriorly in rounded pore-areas. The stmcture intervening between the pore-areas is frequently raised into ridges and prominent monticules, more marked than those which occur on the posterior surface of Stau7-onema, but otherwise similar ; the skeletal networks of both fossils have also the same structure and arrangement ; and their meshes and fibre are of the same dimensions. These facts, and the absence of the true distal margin of the oscular plate in the other specimens, leave little doubt in my own mind as to the relation which this fossil bears to the latter. 1 eaimot but regard it as a part of a distal expansion of the oscular plate of St<iu7'one7ua. </