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*Omnes res createe sunt divine sapientix et potentix testes, divitie felicitatis humane :—ex harum usu dJonitas Creatoris; ex pulchritudine sapientia Domini; eX ceconomia in conservatione, proportione, renovatione, potentia majestatis elucet. Harum itaque indagatio ab hominibus sibi relictis semper xstimata ; a veré eruditis et sapientibus semper exculta; malé doctis et barbaris semper inimica fuit.”—Linnavs.

‘Quel que soit le principe de la vie animale, il ne faut qu’ouvrir les yeux pour voir qu’elle est le chef-d’ceuvre de la Toute-puissance, et le but auquel se rappor- tent toutes ses opérations.”—Bruckyer, Théorie du Systéme Animal, Leyden, 1767.

4 . The sylvan powers Obey our summons; from their deepest detls The Dryads come, and throw their garlands wild And odorous branches at our feet; the Nymphs That press with nimble step the mountain-thyme And purple heath-flower come not empty-handed, But scatter round ten thousand 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 crop the lily, and each sedge and rush That drinks the rippling tide: the frozen poles, Where peril waits the bold adventurer’s tread, The burning sands of Borneo and Cayenne, All, all to us unlock their secret stores And pay their cheerful tribute.

J. Taytor, Norwich, 1818.



NUMBER CIX. Page I. On Stawonema, a new Genus of Fossil Hexactinellid Sponges, with a Description of its two Species, S. Cartert and S. lobata. By

W. J. Sotuas, B.A., F.G.S., &e. (Plates L-V.) .....-. seer eee: Ll< II. On some new Genera and Species of Araneidea. By the Rev. O. P. Camprives, M.A.,C.M.Z.S., &e. (Plates VI. & VIL)...... 26—-

III. Notes on Foraminifera. By E. Percnvat Wrieut, M.D., F.L.S., Professor of Botany in the University of Dublin, Secretary of the Royal Irish Academy .......-. sees eee e rete eee ee enees 40

IV. On the close Relationship of Hydractinia, Parkeria, and Stromatopora ; with Descriptions of new Species of the former, both Recent and Fossil. By H. J. Carter, F.R.S. &c. (Plate VUI.).. 44

V. Descriptions of twenty-five new Species of Hesperide. By WW OE WiEBON Se Sa So. al A RE saa eel ig otters dele ale 76

VI. Remarks on Observations by Captain Hutton, Director of the Otago Museum, on Peripatus nove-zealandie, with Notes on the Structure of the Species. By H.N. Mosrxey, Fellow of Exeter

College, Oxford, Naturalist to the Challenger’ Expedition ...... 85 - VII. On Rhopalocera from Japan and Shanghai, with Descriptions

of new Species. By Anruur G. Buturr, F.LS. &e.... 006-0. 91 VIII. On Polyzoa from Iceland and Labrador. By the Rev.

Tuomas Hincxs, B.A., F.R.S. (Plates X. & XI.) ...... 26. eee 97

Christian Gottfried Ehrenberg; Corals in the Hunterian Museum figured by Ellis and Solander; Descriptions of new Species of Biattide ‘belonging to the Genus Panesthia, by Prot. James Wood-Mason; On some Facts relating to the Nutrition of the Embryo in the Egg of the Fowl, by M. ©. Dareste ; On the Structure and Organization of the Polyphemide, by Dr. C. Claus; On the Colydiide of New Zealand, by D. Sharp. . 115—120


IX. On two Vitreohexactinellid Sponges. By H. J. Carter, ERS. & 0.7 (PIRI) ee ee ee een eure a 121


Page X. List of the Species of Crustacea collected by the Rev. A. E. Eaton at Spitzbergen in the Summer of 1873, with their Localities and Notes. By Epwarp J. Mrers, F.L.S., F.Z.S., Assistant in the Zoological Department, British Museum...........eeeeeeee ences 131

XI. Descriptions of new Genera and Species of New-Zealand Coleoptera.—Part IV. By Francis P. Pascos, F.LS. &. ...... 140

XII. Contributions to the History of the Hydroida. By the Rev. PEAMACeAINCKS, B.A., EVES. . (Plate KUL). ceo ase cd velatp ee e 148

XIU. New and peculiar Mollusca of the Order Solenoconchia

procured in the ‘Valorous’ Expedition. By J. Gwyn JEFFREYS, PRT DES ss gio MEO Sissel! sa Rhard Spebiece ah o's sli ee clei 153

XIV. On the Fundamental Error of constituting Gromia the Type of Foraminiferal Structure. By G. C. Wauuicu, M.D., Surgeon- Major Retired List H.M. Indian Army ....... a Wi ath Saas 158

New Books:—The Primeval 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. &e. ...... 174

Eroceedings of the Royal Society... 5.3%... e-cs0 Aiea ssiseee daaean » 180

On the Reproductive Apparatus of the Ephemeride, by M. Joly ;

y On the Nervous System and Muscles of the Echinida, by M. L. Fredericg ; Physiological Experiments on the Functions of the Nervous System in the Echinida. By M. L. Fredericq; On the Motile State of Podophrya fixa, by M. E. Maupas; On Helix villosa, Draparnaud, by J. Gwyn Jeffreys; On a new Species of Naultinus, by Dr. Buller ........0.0eeeeeenes 193—200


XV. Description of Bdelloidina aggregata, a new Genus and Species of Arenaceous Foraminifera, in which their so-called ‘“ Imperfora- tion” is questioned. By H. J. Carrmr, F.R.S. &c. (Plate XIII. SMe 15:3) 2 oslo, 9) yest aka) Ket wake & a MRM oe heed cde x fe ke hoe aE 201

XVI. On the Locality of Carpenteria balaniformis, with Descrip- tion of a new Species and other Foraminifera found in and about Tubipora musica. By H. J. Carter, F.R.S. &e. (Plate XIII. figs. Tae ercier hate -atat Siow Paw a’ ad lnca sus Sie MAbralal hy Syaldeseele| Pee ¢ eee 209

XVII. Descriptions of two new Genera and Species of Indian Mantide. By Prof. J. Woop-Mason, Assistant Curator, Indian Miriserm s aCe Ca eis i.c''s uf sacks yet trae Ceatelateroer eee welkih axle 219

XVIII. Descriptions of new Species of Conide and Terebride. By Epe@ar A. Suiru, F.Z.8., Zoological Department, British Mu- SOUR sini xce)a sie de at ond dy a Shap NEN Ma Picci: ve sg eee heater nae 222

XIX. New and peculiar Mollusca of the Patellide and other Fami- lies of Gastropoda procured in the ‘Valorous’ Expedition. By J. Gwyn Jerrreys, LL.D., F.R.S,......... Be) oc), Ae 231


Page XX. Description of Miphargus puteanus, var. Forelii. By Auors EupmunGD EA) UE MAOE TAG Bea Ith swe 5 ne UNG a ey RUE Ra Cob a 243

XXI. Hermaphroditism among the Parasitic Isopoda. Reply to Mr. Moseley’s Remarks on the Generative Organs of the Parasitic Isopoda. By J. Butuar, B.A., Trinity College, Cambridge ...... 254

XXII. Additions to the Coleopterous Fauna of Tasmania. By Cranes Or iW ATEREOUSE: -ites ha ets ctelvet 4h old Miohdee oie aint 256

New Books :—Ostriches and Ostrich-Farming, by Julius de Mosen- thal, Consul-General of the South-African Republics for France, &e. &e., and James Edmund Harting, F.L.S., F.Z.S., &e.—On the Foraminifera of Barbadoes (Etude sur les Foraminiféres de la Barbade, &c.), by M. Emest Vanden Broeck, &c....... 257, 260

Proceedings of the Geological Society. ...........eeceeeeeeneees 260

Note on the Femoral Brushes of the Mantide, by Prof. J. Wood- Mason ; On the Development of the Antenne in the Pectinicorn Mantide, by Prof. J. Wood-Mason ; On the Power possessed by certain Mites, with or without Mouths, of living without Food through entire Phases of their Existence or even during their whole Lives, by M. Méenin ; Note on the Nidification of the Aye-Aye, by MM. A. Milne-Edwards and A. Grandidier ; Note on the Phenomena of Digestion and on the Structure of the Digestive Apparatus in the Phalangida, by Félix Plateau; The Gourami and its Nest; Zoology of the ‘Challenger’ Expedi- tion 5; Rate’ot Growth. of Corals.....'...s6c0 165 048 0.00 de 269—276


XXIII. On the Distribution of Birds in North Russia.—I. On the Distribution of Birds on the Lower Petchora, in North-east Russia. By J. Ac Hanya BeowinyhiZ. 02 cise) sith sigs clas soe ses aes are 277

XXIV. Description of some Sponges obtained during a Cruise of the Steam-Yacht Argo’ in the Caribbean and neighbouring Seas. By THomas Higetin, F.L:S. (Plate XLV.) csc cc ceee ce eens 291

XXV. On the Structure of the Lower Jaw in Rhizodopsis and Rhizodus. By R. H. Traquarr, M.D., F.G.S., F.R.S.E., Keeper of the Natural-History Collections in the Museum of Science and Art, BOG WET co ue a ae ae be oR ecard Manly Gore neat Me Nears Cuca ee 299

XXVI. Description of a new Form of Ophiuride from New Zea- land. By En@ar A. Suiru, F.Z.S., Zoological Department, British

Moneam> (Plate XV.) cawia cels'sis Uoieiew Wahi abr ss «SdgeS alee rn iae 805 XXVII. The Vates Ashmolianus of Westwood, the Type of a new Genus of Mantide. By Prof. J. Woop-Mason .........5.+005 308

XXVIII. Hermaphroditism in the Parasitic Isopoda. Further Remarks on Mr. Bullar’s Papers on the above subject. By H. N. MosELEY, Fellow of Exeter College, Oxford... ... 0... seven eeues 310


Page XXIX. Descriptions of three Homopterous Insects in the Collec- tion of the British Museum, By ArrHur GARDINER BurT.LErR, Ee Rectan was alniduece aloes «sree 2 a0 saa 2c oe 311

XXX. Notice of a Barbel from the Buffalo River, British Caffraria. Bayete, AG nmin uP Est. fab a hs: Piasts lamang bw kv bans alee 312

XXXI. Descriptions of some new se of Reptiles from Mada- gascar. By Dr. ALBERT GinrueER, F.R.S., Keeper of the Zoolo- gical Department, British Museum. (Plate XVI.) ............., 515

XXXII. New and peculiar Mollusca of the Eilimide and other Families of Gastropoda, as well as of the Pteropoda, procured in the ‘Valorous’ Expedition. By J. Gwyn Jerrreys, LL.D., F.RS. .. 317

XXXIII. Notes on New-Zealand Ichthyology. By Jamzs Hxc- Ea PD A A SS Or) BA Pm or PU ae Re cde 339

XXXIV. Observations on the Coccosphere. By G. C. Wauticu, M.D., Surgeon-Major Retired List H.M. Indian Army. (Plate BEN UR ii Gil oc ha’ ches he ic boherosmishersiadie aavia s He,t ahniiguns Setteoeind Oo MOR SRE 342

On Anguillula intestinalis, a new Nematoid worm, found by Dr. Normand in subjects attacked by Diarrhoea of Cochin China, by M. Bavay; On Filaria hematica, by MM. O. Galeb and P. Pourquier; On the Intimate Phenomena of Fecundation, by M. H. Fol; On the Vitality of certain Land Mollusks, by Robt. BY VU SUOATNG ys spake eaie dele seem va tes oleae tele teh OU eee

NUMBER CXIII. XXXYV. Malacological Notes. By Roprrt Garner, F.L.S. &e. 357

XXXVI. On the Final Stage in the Development of the Organs of Flight in the Homomorphic Insecta. By Prof. J. Woop-Mason, Deputy Superintendent of the Imperial Museum, Calcutta ........ 580

XXXVI. Note on the Tubulations Sableuses” of the Etage Bruxellien in the Environs of Brussels. By H. J. Carrer, F.R.S. PPE ALG) OV ea ein: a oiaa naichincy acids ak bc nate sine nie Shain glint 382

XXXVIII. Revision of the Lepidopterous Genus Cleis, with De- scriptions of the new Species. By ArTHuR G. Butirr, F.L.S. &c. 393

XXXIX. On the Elateride of New Zealand. By D.Suarp .... 896

XL. Description of three new Species of Lizards from Islands of

Porres Surat. Joy Ur AL GiNTHER Joico. <9 c0.s ou elesle oie wieteeauea 413 XLI. Notes on Stony Corals in the Collection of the British Museum. By Dr. F. BRUGGEMANN ......55..00sqeeceevesorens 415

XLII. Description of a new Species of Portunide from the Bay of Bengal. By Prof. J. Woop-Mason, Deputy Superintendent of the dridian: Museum, Calcutifaid, 5)... poisne os. 0,8 nase ints wa viione « ¢ete 422

XLII. New Coleopterous Insects from Queensland. By CHARLES SW SE BRHOUSE © 5 vi. cv ss aie via ae (eltyptalodn.e Sy aalahate emtaeehe Mp 5 dot 423



New Book :—Annual Report of the United-States Geological and i Geographical Survey of the Territories, embracing Colorado and parts of adjacent Territories, being a Report of Progress of the Exploration for the year 1874, ty F. V. Hayden, United-States

CGMS teat sid ateertras 66 a es we hs Ai ios cl ane, a) Op a at as 425

Zoology of the Challenger’ Expedition, by P. Martin Duncan, F.R.S., Pres. Geol. Soc.; On the Modifications undergone by the Ovum of the Phanerocarpal Meduse before Fecundation, by M. A. Giard; Note on Vertigo Moulinsiana, Dupuy, by J. Gwyn Jeffreys, F.R.S.; Sponges dredged up on board H.MLS. ‘Porcupine’ in 1869-70, by H. J. Carter, F.R.S. &c.; On the first Phenomena of the Development of Echinus miliaris, by M. A. Giard ; the late John Leckenby, Esq., F.G.S., F.L.S, 429—436


XLIV. On the Variability of the Species in the case of certain Baghiog: iy Or. Vs ADIOS acts joann cies cust siecue hemes id ohne aera 437

XLV. Descriptions of several African and Australian Lepidoptera in the Collection of the British Museum. By Artuur G. BuTLEr, I Deeg BeAr rig cee bots aa fece Wee 5 oh -oncr one ae Wirdss. se ae ee 458

XLVI. On Ascodictyon, a new Provisional and Anomalous Genus of Paleozoic Fossils. By H. AttEyNeE Nicnoxson, M.D., D.Sc., F.R.S.E., and R. Ernrrinves, Jun., F.G.8. (Plate XIX.) ........ 463

XLVII. On the Elateride of New Zealand. By D.Suarp .... 469

XLVIII. Description of a new Species of Phasmide from the Malay Peninsula. By Prof. J. Woop-Mason, Deputy Superinten- dent, Indian Museum, Oaleittia, si. 1 aie ip. ae olen Bes sgeine ea eae

XLIX. Diagnoses of new Species of Pleurotomide in the British Museum. By Epear A. Smiru, Zoological Department.......... 488

L. On Rupertia stabilis, a new Sessile Foraminifer from the North Atlantic. By G. C. Watuicu, M.D., Surgeon-Major Retired List, HM. Indian-Asmye CPinte Us) 6. eis CGR LY ad Wee tone 501

New Book :—The Ancient Life-History of the Earth. By Prof. H. As iehalson. DED DG iacGain: sant Sas nis oste mec cha em 505

Zoology of the ‘Challenger’ Expedition, 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 Transformism derived from the Evolution of the Den- tary Follicles in the Ruminants, by M. V. Pietkiewicz .. 506—510


Prats I.) i. III. Structure of Stauronema. IV. |

iV.J VIL New Genera and Species of Araneidea. VIII. Structure of Hydractinia, Parkeria, and Stromatopora. IX. Eurete farreopsis; Myliusia Grayi. ; New Polyzoa from Iceland and Labrador. XII. New Hydroida. XIII. Bdelloidina aggregata—New species of Carpenteria. XIV. New Sponges. XV. Ophiopteris antipodum. XVI. New Reptiles from Madagascar. XVII. Structure of the Coccosphere. XVII. Broeckia bruxellensis. XIX. New Genus and Species of Paleozoic Fossiis. XX. Rupertia stabilis.





SoS ipecserbnpesccec per litora spargite muscum, Naiades, et circiim vitreos considite fontes: Pollice virgineo teneros hic carpite flores: Floribus et pictum, dive, replete canistrum. At vos, o Nymphe Craterides, ite sub undas Ite, recurvato variata corallia trunco Vellite muscosis e rupibus, et mihi conchas Ferte, Dex pelagi, et pingui conchylia succo.”

N. Parthenii Giannettasii Kol, 1.

No. 109. JANUARY 1877.

I.—On Stauronema, a new Genus of Fossil Hexactinellid Sponges, with a Description of its two Species, 8. Carteri and 8. lobata. By W. J. Souuas, B.A., F.G.8., &e.

[Plates I.-V. ]

Oscar Scumipt’s remark, ‘Die Behandlung der fossilen Schwimme durch die Geognosten und Paliontologen ist eine grausliche,” has the merit of being strictly true, though in fairness it ought to be added that the geologists and paleon- 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 Hexactinellide and Lithistide (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 themselves, and next of the structure and classification of existing forms, The 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. & Mag. N. Hist. Ser.4. Vol. xix. if

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

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

At the present day, however, things are far otherwise with the paleontologists; 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 here still better off since the 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 does 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 Mr. 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 polydiscus (Bocage) (Dactylocalya, Bowerbank), that Stromatopora concentrica and some other species of this genus show no affinities to the Foraminifera, but are Vitreohexactinellid sponges closely resembling Dacty- localyx pumiceus (Stutchbury), and that Manon macropora and a sponge called Chenendopora 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 *, L 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- lide occurring 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 Ventriculite 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 with regard to §. concentrica; Mr. Carter has shown that some Stromatopore are allied to Hydractinia.

Genus of Fossil Hexactinellid Sponges. 3

questing him to make me a collection of these fossils; and from his 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 preservation, while all exhibit the halfcup- shape form which I had noticed previously.

Outward Form (Pl. I. figs. 1-8).—The sponge 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 § of an inch in breadth, and from 1 inch to 3 of an inch in thickness. The object on which the sponge grew is generally a small fragment of coprolite (Pl. I. fig. 6, 4), which in good specimens still remains adherent at or near the point from which the sides of the fan diverge. This point indicates, then, the ‘‘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 (Pl. I. fig. 1, 0), and a thick protuberant mass behind (ibid. p); a 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 (Pl. I. fig. 2, 0) ; and in fractured specimens the distinction is seen to be con- tinued within (Pl. 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 21 inches high by 2 inches broad and 4 inch thick it measures 1 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 different 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 it a short


4 Mr. W. J. Sollas on Stauronema, a new

distance above it, the maximum distance I have 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 abrapt 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 (Pl. I. fig. 9), 5 inches long by 4 broad, and from + to +; 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, where it begins to project freely, it is marked by a number of round, or more usually oval, oscular pits arranged quincun- cially (Pl. 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 (Pl. I. figs. 1 & 3). The variations in size may all be comprised between the extremes of 3!; and 3; 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 a number of oval spaces arranged quincuncially and closely re- sembling the oscular pits in front (Pl. 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 Sponges. 5

which mark, as we have seen, the posterior face, and which probably served as the special pore-areas of the sponge. This arrangement accords with the general rule, that in all cup-shaped and curved fan-shaped sponges the oscules are placed on the interior surface of the cup or on the concave surface 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 this 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 much diminished in thickness; we then see the oscules freely exposed over the denuded area, and dimly to be discerned through 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 (Pl. I. fig. 2, e', and Pl. IL. fig. 1, 0, fig. 2, 0).

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 (Pl, I. figs: 2,4, 6, 7, 8; Pl Ol. figs. 1. & 2)) whiens 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. Sollas on Stauronema, a new

that in a specimen 12 inch high, with an oscular plate uni- formly 4 inch in thickness throughout, it has increased from a mere trifle at the base and the edges to 4 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 bulgings, which form gently 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 course 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 concentricaily, 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 im 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- cimens, 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 Hexactinellid Sponges. 7

to which I have chiefly trusted, only using the former when the latter has not been available. ‘The sections I have had 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 (Pl. II. fig. 2); (2) transverse and at right angles to the surface— transverse sections (Pl. II. fig. 1); (3) parallel to the sur- face, one through the oscular plate and another through the posterior mass—parallel sections (Pl. II. fig. 1, 0, ¢, fig. 3).

The appearances of these sections under the microscope I shall now describe, and in so doing shall contine myself first to an account of the skeletal structure which they demonstrate, referring most of the facts which bear on the mineral charac- ters to a subsequent paragraph.

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

Sections taken through the oscular plate of Stawronema Cartert, from the specimen represented in transverse section on Plate II. fig. 1; all magnified 30 diameters. Fig. 1. Longitudinal section (a, Pl. IL fig. 1). Fig. 2. Transverse section (Pl. II. fig. 1). Fig. 38. Parallel section (¢, Pl. UU. 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 ;}, to +4; of an inch ; but on approaching the node it thickens considerably so 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 rectangulay, 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 with certainty that the fibres themselves are per- fectly smooth and not in any way spined. . |

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

In the centre of the node is a small and very definite cirele, «tz to 33, 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 filled 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 are continuous from one node to another, like the fibre 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 isclear that our quadrilateral cross of fibre 1s really asexradiate one (fig.4), with its arms arranged about three

Diagram of the network of Stawronema. Scale 60:1. a, sexradiate canal; 6, sexradiate fibre.

axes at right angles to each other, and that corresponding with the axes interiorly is a similar sexradiate hollow canal. Now this structure is exactly that which characterizes the rete of the Vitreohexactinellide, 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- hexactinellide 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 siliceous 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-

a mee

Genus of Fossil Hexactinellid Sponges. 9

guished into spicule and fibre, but appears homogeneous throughout. But in deciduous specimens of Aphrocallistes and Farrea the original spicule undergoes a process of absorption and disappears, leaving in its place a hollow sexradiate cavity readily observable in the interior of the fibre. Our sexradiate fibre has, then, in the fossil condition a structure essentially identical with that of the recent skeleton of Harvea 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 difference is that the canals in our fossil are continuous from one node to another, while in recent Hexactinellidee they terminate blindly, as casts of spicules naturally would, their blind 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 speak of the various modes of its fossilization.

The characters of the sponge already described are sufficient to define the genus, which I now propose to call “‘ Stawronema,”’ from the cross-like disposition of the thick skeletal fibres about the nodes of the network, a feature 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 which the half-cone of the sponge may be supposed to be described ; and a third horizontal and concentric with the curve of the fan.

The longitudinal fibres (Pl. II. fig. 4, 2) deviate from a parallel course by diverging, as they mse 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 Hubrochus and the Ventriculites +. 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 goes on, the form of the spicules becomes lost, and that which remains is a simple cylindrical cavity, which led Bower- bank to say that the fibre of Farrea was channelléd like that of the Cera- tina, ex. gr. Luffaria.—Note by Mr. CarTER. | ce ee Journ, Geol. Soc., Feb. 1878, p. 66, fig. 4; Geol. Mag., Sept.

10 Mr. W. J. Sollas on Stauronema, a new

fibres are not, strictly speaking, confined to horizontal planes ; for they curve upwards in gentle ares 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 are 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 (Pl. 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 Aphrocallistes. 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 Aphrocallistes, 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, pl. x.; 1875, vol. xvi. p11.

Genus of Fossil Hexactinellid Sponges. 11

shows that the sexradiate forms are in all probability produced by a radiate growth from the first of the six arms from a common centre: this being so, one can readily see that if the growth of a free radius took place in the course of the excur- _rent canal, it would be subject to a pressure in two directions at right angles to each other—one due to its growth onwards, normal to the surface from which it sptings, and the other parallel to the axis in the direction of the current; and its ultimate position would be the resultant of these two, and would be in just such a position as the spines, 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 off buds, one at the end of each of its spicular rays—. e. in the direction of most