THE DANISH INGOLF EXPEDITION. VOL. VI a. PUBLISHED AT THE COST OF THE GOVERNMENT THE DIRECTION OF THE ZOOLOGICAL MUSEUM OF THE UNIVERSITY. <^V COPENHAGEN. H. HAGERUP. 'RISTEDBl BIANCO LUNO A/S I902-I928. Ql b P1 Contents of Vol. VI a. I. W. Lundbeck: Porifera, I, Homorrhaphidae and Heterorrhaphidae, p. I — 108 (19 plates), 1902. II. W.Lundbeck: Porifera, II, DesmacidonidaB (Pars), p. 1-211) (20 plates), 1905. III. W. Lundbeck: Porifera, III, Desmacidonidae (Pais) p. 1-121. (11 plates), 1910. IV. M. Burton: Hexactinellida, p. 1-18, 1928. ^ THE DANISH INGOLF-EXPEDITION. VOLUME VI. 1. PORIFER A. (PART I.) HOMORRHAPHID,£ AND HETERORRHAPHID.E. BY WILL. LUNDBECK. WITH 19 PLATES AND 1 FIGURE IN Till-; TEXT. TRANSLATED BY TORBEN LUNDBECK. ^ t, ^ ^ ***" ^ COPENHAGEN. PRINTED BY Bl VNCO LI n> ' 1 Q 5 D3 v. 6 Ready from the Press May the 15th ino:. CONTENTS. Homorrhaphida; and Heterorrhaphida.-. Introduction i. Homorrhaphida; 4. Chalinina? 4. Pachychalina 5. Schmidtii 11. sp 5. caulifera Vosni 7. Chalina 10. — oculata Pall 10. — spatula n. sp 11. — groenlandica Frstdt 13. Siphonochalina 13. pulcherrima Frstdt 13- mollicula 11. sp 15. Renierinae 16. Halichondria 16. panicea Pall 17. genitrix O.Schmidt is. fibrosa Frstdt 20. velamentosa Arm. Hans 22. osculum n. sp 23. oblonga Arm. Hans 24. tenuiderma 11. sp 26. colossea n. sp 27. ? difficilis n. sp 28. Kumastia 31. — sitiens O. Schmidt 31. Reniera 34. — urceolus Rathke et Vahl 35. — parenchyma 11. sp 37. folium n. sp 39. ventilabrum Frstdt 41 >. — hyalina n. sp 42. — clavata Levinsen ? 43. cinerea Grant 43. — tubulosa Frstdt 44. laxa n. sp 46. — heterofibrosa n. sp 47. calamus n. sp 18. sp- a 19. Reniera sp. b 50. — SP- c — Voeringii Ldbk 50. Metschnikowia 52. spinispicnlum Cart 52. Petrosia 54. — crassa Cart 54. Phlaeodictyon 56. tuber n. sp 57. elongatum Tops — irregulare n. sp 61. Heterorrhaph ida_- 62. Gelliime 62. Gellius 62. — arcoferus Vosm 62. — angulatus Bow 63. — luridus 11. sp — microtoxa a. -41 — primitivus 11. sp 69. — proximus n. sp flagellifer Ridley and Dendy 71. porosus Frstdt 73. Gelliodes 75' plexa n. sp 75- consimilis n. sp 77- < Iceanapia 7s- — robusta Boaa 7^- Desrnacellinas Biernnia " rosea Frstdt. — annexa O. Schmidt I lesmacella sx- capillifera Levinsen SS. Pi i' 111! \'."\\ hamifera 11. sp 1 ! --t.lt Hamacantha — Bowerbanki 11. sp implicans 11. >]> Porifera. I. By William Lundbeck. The present treatise is the first part of a work on the Porifera collected by the Ingolf-expedition. The material for this work, however, does not consist of that of the Ingolf-expedition only, but I have, for the sake of completeness, included all the sea-sponges, found in our Museum, from Green- land, Iceland and the Faroe Islands, and upon the whole from the territory treated of here. The latter material has especially been collected by the Greenland-expeditions that have been sent by the. Com- mission for the geological and geographical examination of Greenland; partly also by the men of war that have navigated the seas round Greenland and Iceland, as also by some other collectors; especially must be mentioned a considerable collection, made by Dr. Morteusen in [899 at the Faroe Islands. Of the whole material, however, the portion collected by the Ingolf-expedition during its two cruises in 1895 and 1896 forms by far the greater part. The collection of sponges made by this expedition was quite exceptionally great, greater, I think, than any made by any single expedition before. Finally I got from the museum in Bergen by the kindness of Dr. Bruuchhorst the sponges of the Norwegian North-Atlantic Expedition, which I have included here, as the earlier work on those sponges needed a revision. The geographical territory of the present work may therefore be given thus: the eastern part of the Davis Strait and the sea north of a line through the southernmost station of the Ingolf at about 57 L. X. across to the south of the Faroe Islands, that is to say, the whole of the North- Atlantic (species from the Norwegian fjords, however, have not been included). From this territory I have endeavoured to include all the species, also those that are not found in the material, but have been mentioned in the literature as found within the territory. With regard to the terms used in the descriptions I shall premise .1 few remarks. The terminology employed in describing the spicules is mainly the same as lias been used by Ridle\ and Dendy and by Topsent, and upon the whole by all recent authors, so that an explanation will be unnecessary. For the more or less membranous part of tin- body of the sponge which forms the surface and covers the subdermal cavities, the term dermal membrane has been employed. It ma\ be thinner or thicker, and more or less pronounced; where the subdermal cavities are large and wideh The Engolf-Expedition. VI. i. PORIFERA. I. ad it is distinct and easily separable, while in forms with small subdermal cavities it may be little or not at all marked off inwardly. The term Ectosome, which is now most frequently used of this part, 1 have not employed, as the question is not here of a structure of a definite morpho- logical value, and the term dermal membrane is therefore only used as a descriptive term. The dermal membrane may be a thin membrane without spicules, but may also be provided with spicules variously grouped, and in the latter case we may speak of a dermal skeleton, but this skeleton is frequently not distinctly marked off from the other skeleton of the sponge, being only its outer part. The dermal membrane is frequently, especially when it is a thin membrane without spicules, supported on spicules projecting from the skeleton; in such cases I have employed the descriptive expression that the dermal membrane is pierced by spicules and the surface shaggy. In the undamaged sponge a real piercing hardly takes place, but is only apparent; it is also probable that it is especially prominent in specimens kept in spirit, on account of the contraction. It has been correctly observed by Vosmaer in Porifera •> (Bronn's Klassen und Ordnungen), and by many other authors, that the terms pores and oscula have certainly been used of structures far from always being homologous. Of late the term pore has often been used of the apertures of the incurrent canals in the subdermal cavities, and then the pores of the surface have been called dermal pores {Ostfa Minchin). This I think unnecessary, as it does not come nearer the homology. Vosmaer (Tijdschr. d. Nederl. Dierk. Vereenig. (2) III, 1890 — 92, 238) has proposed other terms, trying to establish homologies with regard to the excurrent apertures, so that he calls the aperture with which his cloaca opens outward, osculum, and the openings into this cloaca of the excurrent canals procts, when there is only one opening, and proctions, when one canal has more than one opening; in certain sponges the osculum is wanting, and then the apertures of the excurrent canals on the surface are procts or proctions. In the same way he uses the term stomata for the pores on the sur- face of the sponge, or stomions, if there are more than one pore for each canal. Hitherto he has only tried to establish this terminology in the Hexactinellids and Tetractinellids; whether it may be used there may be doubted, and at all events it cannot be used in the Monaxonids ; in forms with large subdermal cavities, for inst, it will be impossible to distinguish between stomata and stomions. Therefore I always use the term pore of the incurrent openings on the surface of the sponge, while I use the term osculum or oscula of the excurrent opening or openings on the surface, but in the latter case it may sometimes be a matter of judgment what is to be called osculum. In a tubular sponge as a Siphonochalina or many species of Reniera I call the opening of the tube osculum, and in a leafshaped sponge with the excurrent openings on one side I use of those the term oscula. The diffi- culty occurs' at forms of transition between the above mentioned, as for inst. funnel-shaped or open- calicular sponges, but in these cases the signification of the terms used will appear from the description. Minchin is surely right, when he says (Laukester: A Treatise on Zool. II. The Porifera and Coelen- terata, 1900 pp. 23 and 36), that most frequently these questions can neither be decided by outer study nor by anatomical examination, but only by the knowledge of the development of the individual forms. For the present we must therefore be satisfied with knowing that the terms used do not imply homologies. Although, of course, the pores of a given sponge may be found in all degrees between open PORIFERA I and slmt, I have thought it serviceable, as a rule, to give the measured limits of the sizes of the pores in the different species. By the examination of the spiculation and the spicules I have especially endeavoured to give exact measures, as also to give figures of the different forms. As the spicules prove to be upon the whole constant with regard to size and form, they form the best specific characters. At the same time I have tried, as far as possible, always to find the younger phases of the individual forms of spicules, which I have drawn together with the pictures of the fully developed spicules. By this examination it has proved to be a general rule that almost all spicules are begun in about their ftdl length, and then the growth takes place exclusively by apposition, and sometimes by apposition after fixed lines. A growth in conformitv with the organic growth does not take place, neither any growth by < temporaneous resorption and apposition. According to this the younger spicules must always be inscribable in the fully developed ones, and from this follows again with regard to the microsclera that the smaller forms are not, as is commonly stated, forms of development of the larger ones, hut independent, fully developed spicules'). If, for instance, we have a sponge with sigmata, and these, as is generallv the case, are varying in size, then the smaller sigmata are not young forms of the larger ones; by apposition the smaller ones would only become thicker, but very little longer. That this view is correct is corroborated by the finding of quite thin young forms having almost the same length as the grown ones. In the single cases account of this fact has been more particularly rendered by the description of the species. In this respect the sponge-spicules, as will be seen, form a parallel to the silicious shells of the diatoms, which, once formed, do not show any growth, properly so called, but only grow by apposition partly after fixed lines. Of microsclera I have in this part onl) treated of the forms found in Heterorrhaphicke. With regard to the cheke and anchorse cpiite the same thing has been fully shown by Lev in. sen (Studier over Svampe-Spicula. Yidensk. Medd. fra den naturh. Foren. i Kobenhavn for 1893. 1894), and in the next part of the present work I expect to corroborate the statements of this author for a great number of forms. As to systematism I have, for the forms treated of here, chiefly followed Ridley and Dendy, partly also Topsent. I have kept the family Heterorrhaphidce of Ridley and Dendy, as it seems to me to be naturally enough bounded, and I do not, as does Topsent, think that we are more justified in using the megasclera than the microsclera as distinguishing characters. The family Poeci- loscleridcr of Topsent, which is chiefly characterized by monactinal megasclera, includes nevertheless the genus Desmacidon s. 1. with diactinal megasclera, and this genus is chiefly distinguished from Gelliodes by its having chelate microsclera; if no regard is paid to the microsclera as a distinguishing character, Gelliodes might as well be classed with the Poeciloscleridce. < hi the other hand I think with Topsent that Tedaniince by their spiculation are related to the Dendortcince, and therefore the) have not been included here; at present more genera without chelate microsclera or quite without microsclera are known, which nevertheless no doubt must be classed with the Desmacidonidae. As I have explained more particularly in the mentioning of the genus Phlaodictyou (/?/ M I must, however, here notice that O. Srhiiii.lt (Spongien d. adriat Meeres [862, p Ithough with ivy. to these spicules supposing a growth like the organic growth, says of .Me charakteristischeu hakenformigen KSr] Gattung Esperia : In einigen Arten kommen ... kleinere und grossere Formen vor, allein .lies sind in 1 Species zwei Arten solcher Korperchen, nicht junge und alte . Thus he has correctly interpreted this pheiiomi 1 PORIFERA. I. chalina olim) I have thought it correct to break up the group Phlceodictyince, and classed its two genera, one with Homorrhaphidce, the other with Heterorrhaphidce. It would seem as if the larvae in the Monaxonida show group characters (Maas, Topsent), and it is not improbable that the systematism will be highly altered, as for inst. Bidder has altered the systematism of the calcareous sponges according to quite new and at all events very interesting views. At present, however, I think the division of the sub-order Halichondrina into the families Homorrkaphidce , Heterorrhaphidce , Desmacidouidce and Axinellidce to be the most natural — as also the most practical one. Order Monaxonida. Suborder I. Halichondrina. Fam. I. Homorrhaphidae. Subfam. i. Chalininee. The subfamily Chalinince the only distinghuishiug character of which is the amount of spongin uniting the spicules into fibres, cannot, as has also been generally recognized, be kept sharply distinct from the Renierince, as the least sponginous forms form a transition to these latter, while on the other hand forms with much spongin and reduced spiculation form a transition to the horny sponges. In the present work I have tried to make the distinction in the following way: to be referred to the Chalinince a species must have at any rate the primary fibres quite sponginous, even if the mass of spongin is small. If this is not the case, I refer the species to the Reniera, even if, as is the case in several species of Reniera, separate longitudinal fibres with a rather large amount of spongin are to be found; neither do I take into consideration a higher development of spongin in the basal part or stalk of the sponge. When the distinction is established in this way, we shall, in by far the most cases, get an outer characteristic, viz. the cousistencv; even Chalinince with very little spongin will show an elasticity that is not found in the Rem'era-species. Thus the distinction seems to me to be in most cases quite natural, although it cannot be said to have solved the question. While it is thus very difficult to mark off the whole group, it is not much better with regard to the genera. Many of these are based on characters running gradually into each other, as for inst. on the number of spicules in the fibres, by which character it has been tried to distinguish between Pachychalina and Chalina, although there is no distinct difference; also the outer form has been used as a distinguishing character, by Lendenfeld even to an extreme degree. It is to be supposed that the great number and richness in forms of the Chalinince have led to this condition of things, for it may be said, I think, that this subfamily, a few particular forms excepted, has no more value as a systematic group than the genus Rem'era; this genus might be divided into genera after the same characters, but the limits between these genera would be doubtful; several of the characters, :aken for inst. from the skeleton and the surface, by which genera of the Chalinince are characterized, are in the Reniera used as specific characters. There has, however, been no opportunity for a more PORIFERA. I. thorough study of the Clialiuiua\ as the whole material has only comprised six species belonging to three genera. The Chalinince are forms generally found in more shallow water, although a few species reach to a depth of ca. 150 fathoms. A phenomenon frequently seen in the Chalinince and with special distinctness in dried speci- mens where only the skeleton is left, is a formation like yearly rings. In longer 1 tranches they are often seen in great numbers above each other, their form most frequently more or less resembling a conical surface. If a branch is cut through, one or more concentrical rings will be seen. T! yearly rings are formed by the meshes of the skeletal net being in these places finer than in other places, and especially by the presence of more transversal fibres than in the part just inside of the spot, and in this respect these layers are constructed in the same way as the surface. The phenomenon evidently is one of growth. It has already been mentioned by Bowerbauk (Mon. of. Brit Spong. I, 152) who also thinks it to be a phenomenon of growth. Pachychalina O. Schmidt. The form lobose or digitate, branched or unbranched, the sponge solid. The fibres polyspicular with more or less spicules. Spongin differently developed. 1. P. Schmidtii n. sp. PI. I, Figs. 1, 2. PL VIII, Figs. 1, 2, 3. Club- or fiugersliaped. The fbrcs forming a rather regular skeleton of primary longitudinal fibres and secondary transverse fibres, the meshes mostly rectangular. The longitudinal tibres with numerous spicules, the transverse fibres most frequently with fewer spicules ; always a distinct spongiu- sheath. Oscula spread on the surface, sometimes with a tendency to a marginal position. Spicules and elastic, the stalk is hard. The surface of the sponge is even and looks almost smooth, although il densely, but quite short shaggy, the spicules of the ends of the primary fibres projecting a little. The dermal membrane appears as a thin transparent membrane; it rests on the subjacent skeleton. .,\\A if (if Homaodictya are dried, as is often the case with old specimens in museums. These spi nave perhaps been washed out at tin- preparation, or, what is also often the case, tin have been found dead on the beach, and the si have long ago rotted and lain washed away. In such cases the chehe, which are 1101 connected with the skeleton, would either be quite wanting or only a few be left. Ii is also to be supposed that sue! mnding has taken -, more than once 8 PORIFERA. I a piece of the skin is cut off, the meshes of the subjacent skeleton is by the microscope seen through the skin, and the ends of the primary fibres project from the nodes. As the transverse fibres of the skeleton are mostly formed of single needles, this skeleton appears as an irregular, mostly unispicular reticulate work, most frequently only in the nodes united by spongin. Otherwise no spicules are found in the dermal membrane. The pores are round or oval openings, and are found, single or two or three together, in the meshes formed by the subjacent skeleton; the size is from o-03mm to o-i2"m'. Oscula are round, sometimes a little oval openings of a diameter of i — 4nira, they are found dispersed everywhere on the branches in rather great numbers; when the branches are somewhat compressed, they are often set in rows on the edges, and they may also be more numerously or almost exclusively found on one side of the branch; but upon the whole they are best characterized as dispersed. They are often a little projecting, and these projections may grow into papillse of a length of 7'""' (in which cases we have, perhaps, a beginning branch). On the stalk there are no oscula at all. The skeleton is chiefly of the same structure as in the foregoing species, and built upon the principle which upon the whole is found in the Chalininae. Longitudinal fibres (primary fibres) run longitudinally through the sponge, and spread to all sides like a sheaf, reaching to the surface where they project a little; they are united by transverse fibres (secondary fibres) into a rather regular net- work. Far the greater part of the longitudinal fibres are polyspicular, but with far fewer spicules than in the foregoing species, and also unispicular fibres are seen; otherwise the fibres are somewhat different with regard to their thickness and the number of spicules, the thickness being about between the thickness of a spicule and 0-09"', and the distance between the longitudinal fibres is ca. o-i2mm — 0-17"""; thus the fibres are considerably thinner and the reticular work finer than in the foregoing species. Neither do the transverse spicules here form coherent fibres, but reach only from one longi- tudinal fibre to the next, and are for a great part formed of but one spicule; in the inner part of the mge they are far from each other, so that the meshes are more or less rectangular, but towards the surface they are nearer to each other, and here the meshes are more or less quadratic. The spongin is lmt by far so strongly developed as in the foregoing species, and most frequently it forms no distinct sheath or only a very thin one round the spicules of the fibres; in the nodes it is distinctly seen; the transverse spicules are not generally quite surrounded by spongin, but only cemented at the ends. Besides the skeletal tissue thus constituted, some fibres are seen here and there running longitudinally along the branches without going to the surface, which fibres may divide and anastomose; the}- are a little stronger than the regular longitudinal fibres, and have more spongin forming a distinct sheath. Towards the base of the sponge the amount of spongin is greater, and the spicules of the fibres are here surrounded by a distinct spongin-sheath. In the hard, solid stalk the amount of spongin is very considerable, and at the same time it passes from colourless to yellow'; the intervals between the fibres are here very small, and the whole mass forms a very solid tissue. Spicula are straight ore most frequently slightly curved oxea, evenly tapering. The length is between 0118 and OT48mm, and the thickness 0-008— o-oii4""". Shorter and finer needles, to quite fine ones, developmental forms, are also found in small numbers, as also a few styli. Although Yosmaer does not give the length of the needles, the species is so well consistent with his description and pictures that I think the determination to be sure; Yosmaer seems to attach PORIFERA. I. some importance to the presence of the outermost little, marked off point in the oxea; such a form the point, however, is frequent in mam species of sponges. I have been able to examine the original specimens of Levin sen, and have found them to be quite consistent with my specimens. The spe- cimens both of Vosmaer and Levinsen are presumabl) younger forms, and therefore unbranched or twobrauched, while during growth the species becomes more richly branched. Gemmulce. The two specimens in hand have both been attached to the shell of a large Modiola modiolus together with a Homceodictya and a Myxilla\ they have both been broken off, but the shell has been kept. The stalk spreads at the base into a little incrusting part with a skeleton of irregularly arranged, very sponginous, polyspicular fibres, and between these a mi umspicular network. This part was closely filled with the bodies described by Bowerbank under the head of Diplodemia vescicula as ovaries (Mon. Brit. Spong. II, 357, III, PI. I. XX, fig. 121; but when Diplodemia vescicula by 0. .Schmidt (Grundzuge einer Spongienfauna d. atlant. Gebiet 1870) had been declared to be a fragment of a Chalinine, Topsent in 1888 (Compt. rend. CVI, 1299) referred it to Chalina ocztlata, and described the structures, by Bowerbank called ovaries, as gemmulse. The gemmulse of the present species are, with regard to their whole structure and the place when- they are found, quite consistent with the description given of those in Chalina oatlata. They are found in the verv lowermost part of the stalk adjoining the underlayer, and in the basal spreading of the stalk to a number of about a hundred in one specimen and a little fewer in the other. They are closeh crowded together, the form is oval, the length is on an average i'37mm and the breadth o-83mm. The colour (in spirit) is vellow. They are situated in the skeleton of the basal spreading closeh connected with the fibres. Thev consist of a capsule of quite the same appearance as the spongin and furnished with rather close-set spicules, running parallel to the surface and of the same kind as the other spicules of the sponges, and also here as in Ch. oat lata fibres seem to run through the capsule. I have not been able to find any foramen. The contents of these gemmulse appear under the microscope, but without any more close examination, as a whitish, strongly granulous substance. The specimens are taken towards the end of May. Besides in Chalina oai/ata Topsent 1. c. mentions similar structures 111 Cli. gracilenta How.; in this incrusting species thev are also found towards the substratum, but they are here smaller, Thus we know at present three Chalininae, in which these structures are found. That the) are really gemmuke cannot of course be decided with certainty, until their development has been examined. Their beiu.^ found, at all events in Ch. oai/ata and in the present species, quite down at the base oi the hard, compact and apparently dead stalk would, if they are gemmulse, seem somewhat particular. Locality: Vestmanhavusfjord in the Faroe Islands, depth ca. 70 fathoms, two specimens (Th. Mor- tensen). Geogr. distrib.: The species is before known from the I:. units Sea (the locality with a qi (Vosmaer) and from the Kara Sea, depth 6 fathoms (Levinsen). Remarks. The Pachychalina oblonga Arm. Hans, enumerated b\ Vanhoffen (Gronland-Expe- dition der Gesellsch. fur Erdkunde zu Berlin, II, 1, 1897, 248) from Karajak-Fjord in North Greenland, is a Reniera (see pag. 51). The [ngolf-Expedttion. VI. t. IO PORIFERA. I. » Chaiina Grant. Form somezvhat varying^ often digitate and more or less branched^ or leafshaped. Fibres uni- spicular or at all events with quite feio spicules; spongin variously developed, often copious. i. Ch. oculata Pallas. PI. VIII, Fig. 7. 1766. Spongia oat lata Pallas, Elench. zoophyt, 390, 239. 1767. Spongia dickotoma Linn., Syst. Nat. Ed. XII, 1299, 14. 1776. — Miiller, Zool. Dan. Prodrom., 256, 3088. 1842. Halichondria oculata Johnston, Hist. Brit. Spong., 94, 2, PI. Ill, figs. 1 and 2. 1864. Chaiina oculata Bowerbank, Mon. Brit. Spong. I, 208, PI. XIII, fig. 262; II, 361; III, 169, PI. LXVI, figs- i—3- 1887. Euchalinopsis oculata Lendenfeld, Zool. Jahrb., II, 815, 1. 1893. Levinsen, Det vidensk. Udbytte af Kanonbaaden Hauchs Togter, 418, 15. 1896. Chaiina oculata Lambe, Sponges from the Atl. coast of Canada. Transact. Ron-. Soc. of Canada, Ser. II, Vol. II, Sect. 4, 184, Tab. I, figs. 2, 2 a. Of this species I have, from the territory treated of here, only two specimens; one is a little, unbranched, presumably young specimen of a length of 30"""; it has a well marked stalk, omm long and very thin; the other specimen is larger, of a height of 85"""; it is branched and is npon the whole of the typical form. The skeleton, arranged in the usnal way, is chiefly nnispicnlar, but also polv- spicular fibres are found towards the middle of the branches; but they contain only few spicules. In specimens from the Danish seas, howewer, polyspicular fibres may be seen in greater numbers, so that most of the primary fibres are polyspicular; but also here the number of spicules is only small. Thus the species is somewhat varying with regard to this character, and therefore it is on the border between Chaiina and Pachychalina, between which two genera uo quite distinct limit can be drawn. The spougin is in the present specimen rather strongly developed, so that most frequently a distinct spongin- sheath is found round the spicules; also the transverse fibres are most frequently quite surrounded by a layer of spongin, however thin. The distance between the fibres is on an average ca. o-ilnm. Spicu/a are slightly curved, more rarely straight oxea, evenly and rather gradually tapering. They are more varying in length than is commonly the case, from o-i2— or\']2>ma\ and the thickness varies from about 0-008 — o-oi3imn; a few of the largest needles are found with a thickness of up to o,oi5mm; but the longest needles are not always the thickest ones; an average size of ca. 0-149""" in length and a thickness of o-oii,ni" is by far the most common. Besides these needles which on account of the proportion between length and thickness convey an impression of being fully developed, some finer and quite fine needles are found measured to a length of from 0-08— o-it,""". Some few styli ma)- be found. Locality: Vestmanhavnsfjord in the Faroe Islands, depth ca. 70 fathoms, a little unbranched specimen 1TI1. Mortensen); the Vestman Islands, depth unknown, one specimen (Saetnundsson). Geogr. distrib. This species seems to be very widely sjDread, almost cosmopolitan; it is frequent at the coasts of England (Bowerbank), in the English Channel at the French coast and at the southern point of Britain at Croisic (Topseut), as also along the western coast of Jutland (Leviuseu); on the PORIFERA. I. u Atlantic coast of America it is found from Florida to Labrador (Carter, Lambe, Verril). It is further enumerated as found in the bay of Bengal, the Mergui archipelago (Carter, var. fibrosa, this deter- mination, however, is likely to be doubtful), and finally with regard to Polynesia from the Fidji Islands, New Zealand and the Auckland Islands south of New Zealand (Lendenfeld). Thus the species is spread from 63° 20' Lat. N. to about 50 Lat. S. Its bathymetrical distribution reaches from shallow water, about 4 fathoms to about So fathoms, which seems to be the largest depth, in which it has hitherto been taken. 2. Ch. spatula n. sp. PI. II, Fig. 3, Pi. VIII, Figs. 8— 9. Leaf-shaped or spatulate. slipitate, the blade oval. The fibres form a regular skeleton of longi- tudinal fibres and transverse fibres ivith quadra tie meshes. The fibres almost exclusively unispicular, the transverse fibres consisting oj single spicules connecting the primary fibres. Only little spongin forming no visible sheath. Irregularly running, polyspicular longitudinal fibres with more spongin are present. The surface finely shaggy from projecting spicules. Oscula have a someivhat projecting edge, they are spread and found on both sides. Spicula o.vea ir/g-^o-jj""". This species has a fine and regular form like an erect, oval leaf running below into a stalk passing evenly into the leaf. The height is full 14"", of which ca. 6"" may he put down as stalk: tin- largest breadth of the blade is 65""T1. Below the stalk is cylindric, and passes by degrees into the flat blade. The thickness of the stalk in the middle is ca. 8"""; the blade is thickest below, and has here a thickness like that of the stalk, 8 9""", in the middle its thickness is ca. 6mm. The nether half of the margin of the blade where the transition from the stalk is still felt, is rounded, while in the upper half part it is drawn out to a rather sharp edge. The colour (in spirit) is whitish yellow. The con- sistency is elastic, but the sponge is rather soft. The surface is smooth, but finely shaggy from the projecting spicules. The dermal membrane is very thin and transparent, and rests on the skeleton below, the ends of the primary fibres projecting through it. When the sponge is seen in spirit the very close-set round subdermal cavities or mouths of the incurrent canals shine through the skin; thev have on an average a diameter of imm; in some places they are seen to he incompleteh separated, so that thev run into one another and form irregular lacuna.-. Oscula are spread on both sides oi the sponge, a single one is placed quite at the edge; they are also found on the stalk down to tin- lower third part of it; they are circular openings with an average diameter of 3'""; their margin is some- what projecting, so that they have a sharp edge; the canal into which the) lead, does not run hori- zontally inward, but obliquely downward, ami therefore oscula do not point horizontally outward, but a little obliquely upward, so that the margin is most projecting at the lower edge of the oscu aperture. The pores are situated in the thin dermal membrane; the\ are round or roundish holes ,.| verv varying sizes measured from cron o-27m,n. Tlu-\ are found on both sides of the sponge, and continue also down on the stalk. In most places tin pores are placed dose together; reduce the membrane to a network, SO that the pores are onh separated by thin strings of I such cases they get an irregular polygonal form, and may get a still greater size than the mca given. When a piece, cut off parallel t<> the surface, is examined under the microscope, the skeleton l2 PORIFERA. I. under the skin is seen as a unispicular, irregular net work, from the nodes of which the ends of the primary fibres rise. The skeleton is chiefly constructed according to the principle common in the Chalinines. It consists lor the greater part of a rather regular network of more or less quadratic meshes. In the middle of the stalk and the leaf a more open and irregular network is found in which primary and secondary fibres are not to be distinguished; from here fibres issue towards the surface; these primary fibres are directed a little upward on their way to the surface, but they bend a little, so that they meet it at a right angle; especially in the lower part of the sponge the bending upward is quite slight, and the fibres go almost quite horizontally to the surface; in the upper part of the leaf the bending upward is more conspicuous. The secondary fibres consist only of single spicules connecting the primary fibres, and forming together with those the reticular work, but they do not form, or form only to a small degree, coherent fibres. The primary fibres are mostly unispicular; thev mav, however, especially in the lower part of the sponge, be polyspicular, but only with a few spicules alongside. The distance between the primary fibres is about the length of a spicule, or ca. 0-15 — o-i8'nm. The spongin is only present to a small degree, it is distinctly seen in all the nodes, and under sufficiently magnifying powers it may in most places be seen as an exceedingly thin laver covering the fibres; tiie elastic consistency of the sponge implies also that the fibres must be richer in spongin than is the case in the Remera-species. In the stalk the spongin is more richly developed than higher up in the sponge. Besides the regular skeleton described above, some more fibres are found, viz. some rather powerful ones, beginning in the stalk and running as longitudinal fibres up through the sponge branching off and anastomosing. Down in the stalk they are polyspicular and surrounded by a strong spongin-sheath, here they may reach a thickness of o-i2""n; in branching off upwards they become thinner, and the number of spicules smaller down to only a couple of spicules, or thev become quite unispicular; the spongin also decreases, but may, however, still be seen as a thin, but distinct sheath. Outside the skeletal net some spicules are found dispersed; they are generally shorter and finer than the spicules of the skeleton. Spicula are slightly curved, sometimes straight or almost straight oxea, evenly and rather gradually tapering; the curve sometimes is quite even, but sometimes it may also be confined more or less distinctly to the middle part. The length is between 0-19 — cr22ram, most frequentlv it is about o-2o8mm, the thickness is croio — o-oi2mm. As before mentioned some spicules are found spread in the sponge; they are found in no small numbers, and are shorter and finer, up to quite fine ones; by all transitions in size they are connected with the spicules of the skeleton. With regard to the outer features this species recalls the description by Fristedt of the Cha- lina groenlandica from the eastern coast of Greenland, mentioned below, but the spicules of this latter species are abruptly pointed and more curved. Locality. Only one specimen of this beautiful species has been taken, Station 34, the Davis Strait, 65 1 7' I. at. X., S4 17' Long. YV., depth 55 fathoms; the specimen is attached to a stalk of a hv- droid together with two species of calcareous sponges, an ascidian, a couple of hvdroids, a bryozoa, and two octactinise of the genera Voeringia and Paranephthya. PORIFERA. I. j. 3. Ch. groenlandica Frstdt [887. Chalina groenlandica Fristedt, Vega Exp. vetensk. lakttagelser, IV, \\~, PI. 23, fig. [9. This species I have not seen. It must be closely allied to tin- preceding oik-, is leaf-shaped, and has presumably been of a similar form, but among other particulars it differs from it by having the spicules more curved and more abruptly pointed. Fristedt gives the length of the spicules to be o-2mm. The species is only known in a couple of fragments. Locality. The eastern coast of Greenland, depth 140 fathoms (Fristedt 1. a). Siphonochalina (). Schmidt. Tubular, often somewhat branched forms, the surface of the tubes smooth, both inside and out; each tube with a round opening at the summit. The fibres various, unispicular or polyspicular. and with little or much spongin. 1. S. pulcherrima Frstdt. I'll, Figs. 3— 4, PI. VIII, Figs. 10— 11. [885. Chalina pulcherrima Fristedt, Bidrag till kannedom. 0111 de vid Sveriges vestra Rust lefvande Spongise. Kgl. Sv. Vetensk. -Akad. Handl. 21, Nr. 6, 49, Tab. IV, fig. 3a, 3b. Tubular, most frequently several tubes issuing from a common base or stalk, sometimes anasto- mosing, the single tubes with slight, irregular, annular szoellings. The fibres form a regular netzoork oj longitudinal fibres (running towards the surface) and transverse fibres ; the meshes quadratic. , fibres generally unispicular. Only very little spongin. Particular polyspicular fibres running longi- tudinally, are found, especially in the inner part of the skeleton. The surface is finely shaggy from projecting spicules. Each tube ends with a la/ge osculum. Spicula oxea o-jj — o-j 2""". Shorter and finer spicules up to exceedingly fine ones are found, but in rather small numbers, the finest ones have a length of ca. 0-13""". PORIFERA. I. Locality. Jakobshavn in (Greenland, one specimen, depth unknown (Pfaff). Geogr. distrib. Fristedt gives two specimens from Bohuslan. depth ca.90 fathoms (175 mel 2. S. mollicula n. sp. PI. VIII, Figs. 12 14. OJ a somewhat irregular form consisting of a stem, from the ends oj which tubes issue. The fibres form a regular skeleton of longitudinal fibres (running towards the surface) and tr fibres, the meshes are quadratic, rectangular, or polygonal. By Jar the greatest part oj the fibres uni- spicular, only sometimes with a couple of spicules. Only little spongin. {'articular longitudinal fil wanting. The surface finely shaggy from projecting spicules. Each tube ends with an osculum. Spi- cu/a oxca somewhat curved. o-ij—o-ijS""". The only specimen in hand of this species has a somewhat irregular form; it is in two p] fastened to pieces of laminarian fronds, and from here originates 011 one side a cylindric stem, dividing into two branches each ending with an osculum; on the other side of the fastening two shorter tubes issue. The principal stem seems to have been lying more or less horizontally, while the tubes have risen more or less vertically from the stem. The total length of the specimen is ca. 6om'n, and the diameter of the stem 10 — I2mm. The colour (in spirit) is light brown. The consistency is very soft, but elastic. The surface is finely shaggy from projecting spicules. '1 'lie dermal membrane is thin and transparent, and rests on the skeleton below. Each tube ends with an osculum of a diametei of 2 — 3""n; the ends of the tubes are rounded, and accordingly the edges of the oscnla are not sharp. The osculum leads into an oscular canal of the same diameter, and the oscular canals of tin. i are continuations of the canal of the stem. As far as I have been able to decide, the canals run from the surface obliquely upward and inward as in the preceding species, and the excurrent canals open into the oscular tube. The pores are found in great numbers and very close together in the dermal membrane, often reducing this to a reticular work; most frequently they are round; their sizes have been measured to 0-03 — criS"""1)- The skeleton is of quite the same structure as in the preceding species; accordingly it consists of primary fibres running from the wall of the oscular tube in a curved maiinei upward and outward to the surface; these fibres are connected by transverse spicules mostly single or only forming incom- plete fibres. The net is rather regular, and the meshes quadratic, rectangular, or polygonal. The distance between the primary fibres may be somewhat varying; most frequenth it is equal to the length of a spicule, or cri2m"\ but it may be considerably greater, up to o,23" . and upon the whole the ske- leton is more open than in the preceding species; its regular structure is distinctly seen in the tubes, but is far less marked in the stem. The skeleton is almost exclusively unispicular, some of the pri- mary fibres may, however, be composed of a few spicules in their whole course or part of it; polyspi- cular longitudinal fibres as in the preceding species, are not found lure. In spite oi the soft consist- ency of the sponge the spongin is comparatively more developed than in the preceding species, it is 'I This species sln.«s a particular structure, which 1 have not been able quite i" interpret; besides priti projecting through the dermal membrane, there are also here found transverse spicules, so that we get a net of spicules out- side of the dermal membrane. This peculiaritj ma\ perhaps be due to conl m account of the sponge having been kept m spirit, it is also possible that the real dermal membrane lias been ,,, PORIFERA. I. copious in all the nodes, and in the primary fibres it may frequently be seen to surround the spicules completely, while the transverse spicules most frequently appear to be only cemented at the ends. S pic n I a are rather small oxea; they are always more or less curved; sometimes the curve is even, but frequently it is more sharply localized in the middle of the spicule. The pointing varies somewhat, from a fairly long to a quite short, sometimes even rounded point; in the latter case the rounding has a quite small point marked off. The length varies from cri3 — o-ijS"1"1, most frequently towards the latter figure, also the thickness is somewhat varying from crooS— o-oii'nn'. The thickness and length are in no fixed proportion to each other. Shorter and finer needles, up to exceedingly fine ones are found in no small number spread in the tissue, the shortest ones measured had a length of o-092mm. Locality. Egedesminde, Greenland, depth unknown, one specimen (Levinsen). Subfam. 2. Renierinae. Halichondria Fleming. Without definite form, forming incrustations, lumpy or more or less erect. The needles without any real order spread in the tissue, sometimes forming fibres, but no regular reticulate skeleton. Spicula oxen, commonly long and slender, rarely strongyla. Spougiu wanting (or presetit only to a Si arcely appreciable amount). The sponges belonging to the genus Halichondria are usually of no definite form. They mav form incrustations, be formed as thicker or thinner crusts, or be irregularly massive or lumpy, or they may finally be more or less erect and sometimes slightly branched , and it is to be supposed that several species may appear under more or less of these various forms, or at all event varv much in form, and these variations may even to a certain degree influence the other structure (the skin, the skeleton l. The recognition of the species must therefore primarily be done bv means of the spicules, and the other skeletal structures, the nature of the surface etc. can only be of seeoudarv importance. In spite of the general recognition of the secondary importance of the outer form, not only here, but upon the whole in many Monaxonids ') , there has not uncommonly been laid too much stress upon this feature. The species of the earlier authors will, when no exact figures and measures of the needles are given, commonly not be identifiable. Bowerbank thus under the genera Hymeniacidon and Halichondria has twenty- and odd species belonging to the genus Halichondria in the signification used in this work; this, no doubt, is too large a number, but most of these species will not be iden- tifiable without an examination of the original specimens. I It is to be supposed, however, that the secondary importance of the outer form applies especially to the genus Halichondria (and a few other genera, for inst. Hymeniacidon), and is connected with the only little differentiated skeleton of this genus; it is also seen that species of this genus, when they have a skeleton made of fibres, get a more definite form. Halichondria panic ea is a good type of an especially varying and polymorphous species. The outer form of the sponge species, however, is often little known, because many species have been etablished on slight material, fragments or more or less damaged specimens. I am inclined to think that it will be seen by and by, when new collections procure well-kept specimens, that the species often, within certain limits, have a rather definite form. I'ORIFERA. 1. i. H. panicea Pall. PL IX, Fig. i. [842. Halichondria panicea Johnston, BritSpong. 114, PI. X, PI. XI, fig. 5. 1S66. Bowerbank, Mon. Brit. Spongiadte, II. 229, III. P1.XXXIX and XL. 1870. Pellina bibula O. Schmidt, Spongienf. atlant. Gebiet. 42. [870. Amorphina panicea O.Schmidt, I.e. 77. 1SS1. Amorphina megalorrhaphis Carter, Ann. Mag. Xat. Hist. Ser. 5, Vol. VII, 368. 1887. Halichondria bibula Levinsen, Dijmphna Togtets zool.-bot Udbytte, 352, 11, Tab.XXX, fig.4a— b. 1.SN7. Halichondria panic, a Ridley and Dencly, Challeng. Report, Monaxonida, Vol. XX, 2. PL II, Bgs. 2, \ 1887. Amorphina panicea Fristedt, Vega Exp. Vetensk. Iakttag. IV, 421. 1887. Amorphina grisea Fristedt, 1. e. 425, PL 24, fig. 10, PL 27, fig. 10. Of this common species we have a large number of specimens. Itjis most frequently inerusting, especially on alga;, and from this form it grows out into large cushions or lumps, and consequently it is formed as flat cakes, cushions, or roundish or lengthy lumps. Only one specimen, from Reykjavik, lias a more definite form, conical, tapering tubes, or cylindrical, at the summit flat tubes rising from a flat spreading; the tubes have at the summit an osculum leading into an oscular canal. This form corresponds with the picture of Bowerbank, PL XXXIX, fig. 5 and PL XL, fig. 1. In the lumpy forms the oscula are spread and most frequently only present in small numbers. In almost all the specimens the dermal spicules form the well-known regular net of meshes with three, four, or many sides, in which net the pores are lying, often so close that the membrane is reduced to a mere net- work. Now this net may be rather varying in appearance, and ma) also be quite wanting, so that the dermal spicules are lying closely packed and in all directions. The character on which the must chiefly be based, is the form of the spicules; they are very long tapering, always a little curved, and this curve is exceedingly frequently seen as a rather sharp bend in the middle. The size of the spicules is somewhat varying from 035 — i'm"; this latter size is given by Carter for his species //. megalorrhaphis, his own opinion of which is that it is only a variety of panicea, and Ridley and Dencly give, 1. c, several sizes between the measures given above. The largest length of measured by me, is ca. cr6,nm. Among the spicules are also seen styli and monstrous forms, but alv. only sparingly. The genus Pellina of Schmidt, which was based on the presence of a distinct skin with a net of spicules, is, as has been shown by Grentzenberg (Die Spongienfauna d. Ostsee. Inaug. Dissert. Kiel, 1891, 12) and Levinsen (Det vidensk. Udbytte af Kanonbaaden Haueh s Togter, 1893, 115) by an examination of the original specimens of Schmidt, not to be distinguished from tin Halichondria, and the species Pellina bibula is identical with //. panicea. I have had occasion examine one of the specimens of Fristedt of and have not been a find any character separating this species from //. r As has already been mentioned, some of Bowerbanks species will, no doubt, prove to be identical with //.panicea, what can only be decided with certainty by an examinati inal specimens. Levinsen, in the work quo Midler (Z Danica, III, 71, Tab. CXX) to pant nd judging b\ the figure ii can scarcely belong to air species. Also Johnston's II. coalita (Brit. Spong. and Lithophytes [35, PI. XII. fig. 1 Le- vinsen been referred to this species; the s] uston, do not, to be sure, resemble 1 VI. i. jg PORIFERA. I. those oi pan iira, but I have had the opportunity to examine a piece sent by the Rev. A.M.Norman under the name of //. coalita, and the spicules of this piece agree very well with those of H. panicea. Sell mi dt's Reniera simitubulosa (Die Spong. d. adriat. Meeres, 1862, 75) would, according to his expressions in Grundzuge einer Spong. Faun. d. atlant. Gebiet 1870, 42, also seem to belong hither, but this species is otherwise not easily judged. Greutzeuberg, I.e. 13, is of opinion that Amorphina pasiscens from the North Sea, established, but very incompletely described by Schmidt (Jahresbericht d. Commiss. zur wisseusch. Unters. d. deutsch. Meere in Kiel fiir 1872 — 73, 115) is also H. panicea, what also seems rather likely. Finally Top sent in his account of the species of Bowerbauk (Revue biol. du Xord de la Fr. VII, 1894, 14) expresses the opinion that further Hal. caduca, incerta, ambigua, IIx/u. Tliomasii and tegeticula are synonymous with panicea. It must however, be remembered that Hal.incerta and Hym. Thomasii belong to those species, to which Bowerbank attributes two forms of oxea; if we are to regard it to be correct that they have been referred to pan /era, it must consequently be supposed, that Bowerbank has interpreted developmental forms of the needles as special forms. In Johnston I.e. a complete list is found of the earlier, more or less certain synonyms of the species; to this list may thus be added as probable or certain: Spongia coalita Miill., Halichondria coalita Johnston, Halichondria sevosa Johnston (according to Bowerbank), Pellina semitubulosa O. S.? Amorphina pasiscens O. S.?, as also the species of Bowerbank: Halichondria caduca, incerta and ambigtta, Hyvic- niacidon Thomasii and tegeticula. Locality : Halichondria panicea is a very common species in the northern and arctic seas, and we have it from Greenland: Holstensborg, Egedesminde, Godhavu; from Iceland: Reykjavik, Hvams- fjord, Seydisfjord, Faskrudsfjord, Finnefjord, as well as from station 127, north of Iceland, 66°33'Lat. X., 200 05' Long. W. ; from the Faroe Islands: 6 miles to the N.W. of Kalso, Klaksvig, and Ejdesound. The species is found to no great depth; the greatest depth from which we have it, is 60 fathoms, which is also the greatest depth from which it is given with certainty in the literature. Geogr.distr. The species seems to be completely cosmopolitan; it is found from the arctic seas to the Mediterranean, and is known from Ceylon, Kerguelen Island, the Torres Strait and Japan, and it was taken on the Belgian antarctic expedition between 70° and 71° 18' Lat. S. (Topsent)1). 2. H. genitrix O. Schmidt. PL IX, Fig. 2 a, b, c. 1S70. Amorphina genitrix O.Schmidt, Grundzuge einer Spongienf. des atlant. Gebiet. 41, Tab. V, fig. 9. 1887. Amorphina nodosa Fristedt, Vega Exp. vetensk. Iakttag. IV, 423, PI. 24, figs. 7 — 8. The /or/// most frequently roundish, more or less irregular. The s/irface grooved and ruffled. The dermal membrane with a somewhat irregular reticulation of spicules. Oscula spread. The spicules form no fibres. Spicula oxea tailing, as to their sizes, into two rather well bounded groups, the smaller ones inn — o-ip"'", the larger vjj8 — cr6?""". Under the name of Amorphina genitrix Schmidt I.e. established a species on a few specimens from Greenland, and these original specimens of S c h m i d t I have had before me. The description M Topsent (Arch, de Zool. Experimentale et Generale. Notes et Revues. 1901. 1) gives the depth on which all the sponges of the expedition were taken, to be 400—569 metres; according to this ff. panicea seems there to live at a considerable greater depth than hitherto known. PORIFERA. I. I( by Schmidt is very incomplete, but in giving a new description of the species I shall have chii to restrict myself to the needles and their forms, all the specimens being in a rather bad condition. We have several specimens of the species. One of them mentioned bj Schmidt as having Die Gestalt eines i' , Zoll dieken, handgrossen Fladens . is a piece of a ver) compact, almost suberite- like consistency; it has been growing as a plate over a group of Balani. The surface is more even than in the other specimens; the spicules are closely packed in all directions, and no dermal membrane can be separated from the tissue below. We cannot, however, he sure that the specimen has kept its original skin, and consequently, when Schmidt says: init zahlreichen, verschieden grossen Osculis this is not certain, as the openings in the upper surface of the specimen do not appear to be naturally bounded oscula. The other specimens of the species, of which Schmidt says: Andre gelbliche, faustgrosst Stiicke haben eine kranse, wabige Oberflache, mit Osculis im Grunde der Waben . are roundish pieces of a much looser consistency than the preceding one. The specimens have a highly ruffled surface, which is, perhaps, only so conspicuous, because the skin is wanting, or is only left in places; but where it is left, the surface is grooved, and the grooves separated by sinuous swellings; the derma/ membrane is only found undamaged in a smaller part of one specimen, and here it appears to have a reticulation of spicules about as in H. pam'cea, although coarser and more irregular. Oscula are spread and appeal. as stated by Schmidt, especiallv in the grooves of the surface, hut as to their number and size thing can be said on account of the skin being destroyed. In spite of the difference of tin, specimens as to consistency their relation is seen by the fact, that all the specimens have spicules of the same form and size. In the skeleton, as far as I have been able to observe, no fibres are found, hut the spicules are lying in the tissue in all directions. Spictila are the caracteristic feature of the species; the_\r are oxea, and are exceedinglv varying in length, from (1-09 — 0'67m"\ The medium sizes are the scarcest, so that the spicules may also lie said to fall into two groups as to size; the smaller ones most frequently of a length of between ca. cno— o'lj""", the larger ones ma) be of a length between 0-238 — o-67mm, but, as has been mentioned, the distinction is not sharp. Although the smaller needles are found throughout the sponge, thev seem to be most frequent in the dermal membrane and in th< membranes bounding the canals; they are, however, far from exclusively forming the spiculation these membranes, but are found between the larger needles, and seem always to he arranged mor< less perpendicularly on the larger ones. The larger needles are slender, long tapering, and most quently with a rather sharp bending in the middle; upon the whole the) are formed like the needles in H. pam'cea ; the smaller needles are more or less curved, and evenly, hut not long tapering. That the smaller needles are not developmental forms is seen by the fact, that the thickness is about the same in the smaller and in the larger ones, about o-oimm; the smaller ones being, however, frequently somewhat thinner. On the other hand finer needles ma\ be found, which by their lengtl to he developmental forms of the large ones. The smaller needles resemble to a certain degree the Rem'era-needles, and this, I suppose, is the fact that Schmidt thinks of, when he writes isl iuteressant, weil sic die Qebergange der Xadeln vom Renierentypus in den der Amorphinengruppe direct zeigt . As has been correctly observed by Schmidt, monstrous forms ol the needles are rather frequent in this species; especial!) frequent is among the smaller needles a form as fig. 2 c. Sell PORIFERA. I. figures, PI. V, fig. 9, are altogether monstrous forms, while he gives no figures of the normal needles of the species. The examination of the spicules in the Amorphiua nodosa of Fristedt, of which 1 have had a little piece, has shown this species to be identical with H. genitrix. Its outer form, as described by Fristedt, 1. c, agrees also very well with this view. In the spiculation only the smaller spicules seem generally to be a little finer than in the specimen of Schmidt, and of monstrous forms I have only seen a lew. Othervise the figure by Fristedt, especially of the smaller spicule, is not correct. It is easily understood that Fristedt has not been able to determine the species according to the description and figure by Schmidt, especially, because Schmidt, as before mentioned, only gives figures of monstrous needles. In Fristedt we get the information that the species can reach the size of a human head. Locality. We have of this species four specimens and some fragments, all from West-Greenland; only for one specimen a more particular locality, Umanak, is given. gr. distr. West-Greenland and Spitzbergen (Fristedt). 3. H. fibrosa Frstdt. PI. IX, Figs. 3 a, b, c. [887. Amorphina fibrosa Fristedt, Vega Exp. veteusk. Iakttag. IV 426, PI. 24, figs. 11 — 12. Irregular, more or less roundish or incrusting masses. 77ie derma/ membrane in some places with a close reticulation of spicules, in other places the spicules closely packed. Oscula fezu, spread. The skeleton consists of loose fibres, not distinctly marked. The spicules oxea. Jailing as to size in • groups; the larger o-jj — o-^p""". the smaller 0-17 — o-jp""". ( )f this species there are in the collection some more or less roundish pieces, all fragments, and siime irregular crusts growing on calcareous algse. The best conserved specimens are of a rather firm consistency. The skin shows in most places a reticulation of spicules, closer, but looking coarser than in H. panicea; in other places the spicules are closely packed without forming any reticulation. Oscula are few and spread. The pores are found in the meshes of the dermal reticulation as in H. panicea. The skeleton consists of loose and irregular, not sharply marked fibres, which form, at all events frequently, a vcr\ irregular and indistinct network. The skin is not, or is only in the places where a dermal reticulation is found, separable from the body itself as a dermal membrane properly so called; in the other places the outermost layer of the sponge is remarkable by the closely packed spicules; in a section perpendicular on the surface, this part appears distinctly marked off from the tissue below, and this layer, which is developed into a skin, has a thickness of ca. o'3mm. Spicu/a are oxea, falling into two rather well defined groups of size, which are also of different occurrence in the sponge. The larger ones have a length of 0-35 — 0-59""", most frequently they are " long; they are slightly bent, almost of the same thickness throughout their length, and are evenly, but shortly pointed; their thickness is very varying, but may be rather great, up to o-oiy"""; swelling is not unfrequently found in the middle or nearer to one of the ends. The smaller spicules finer, more or less curved, and vary in length between 0-17 and ev2o,"'m. The larger spicules form the skeleton and the dermal reticulation, while the smaller ones are found in the outermost part of PORIFERA. I. 2i the skin outside the dermal reticulation, and form, especially where no reticul: layer in the outermost part of the skin; they are further found in the membranes thai the canals and cavities, and these membranes have often chieflj these smaller spicules, while the\ seem to form part of the fibres. It is with some hesitation that I have determined this species as H. fibrosa^ although I have had one of the original specimens oi Fristedt for comparison. They agree, ho orm and structure, the fibres have the same degree of development, and the dermal layer shows also in some places reticulation, in others closely [Kicked spicules. The spicules also fall inl nips, but the larger ones are somewhat differing from the spicules of my specimens; they are finer, reaching only a thickness of croiim,n, by which fact the difference between the smaller ger spici becomes less marked; further the) are often more strongly and more irregularly curved, and often longer pointed; Fristedt, who does not mention two sizes of the spicules, states their length to be- ers— o49""", and declares the latter length to be the more frequent; it is to be supposed that an error has taken place in the measuring, as the greatest length measured 1>\ me in the specimen of Fristedt before me, is o,59m,n; nor does the figure of Fristedt agree with what 1 have observed; the spicule pictured by him in fig. n, is far too long tapering and recalls the spicule of //. panicea, while the spicules of the specimen sent to me, are almost altogether more shortly pointed: finally must be men- tioned that spicules with a swelling are also found in the specimen of Fristedt. The smaller spicules agree in form and structure with those in my specimens. According to this 1 must regard my speci- mens as belonging to this species, and especially, as also the thickness of the Large spicules appeared rather varying in my specimens. Locality. West-Greenland; we have two glasses from an earlier time, one without any nearer locality given, the other from Proven. Later the species has been taken on Ikertokfjord, depth fathoms (Th. Holm). Geogr. dish: kike the preceding species this latter one is only known as arctic; besidt West-Greenland it has been taken in the Behring-S trait, depth 25 fathoms (Fristedl I.e.). Note. As we have seen, these two species, H. genitrix and fibrosa belong to the group of Hah'c/iondria-species having spicules of two sizes; the smaller spicules here correspond to those which Bowerbank calls tension spicula , and as species, in which tension spicula are different from skeleton spicules, we find in Bowerbank: Hymeniacidon Tiionnisii. Brcttii. fragilis, lactea, Halichon- dria inconspiaia, incerta and edusa; it will, however, only by an examination of original specimens be possible to get a sure idea of these species; as ha> been mentioned under H. pauicea, Hymeh Thomasii and Halichondria incerta are perhaps synonymous with this species. Fristedt I\. 424) mentions a species, Amorphina renieroides^ a piece of which 1 haw had for examination: spicules of this species, varying from 0-15 0'6min, remind of the spicules in genitrix^ hut it seems to be distinguished from this species by the fact that the spicules arc thicker and not so long tapering, and besides, otherwise contrary to the observations of Fristedt, considerably thicker than spicules of the species; it is likewise distinguished from genitrix by the fact mentioned by l'r that the outermost spicules are more or less perpendicular on the surface. 22 PORIFKRA. I. 4. H. velamentosa Ann. Hans. PI. I, Fig. 5. PI. IX, Figs. 4—6. 1SS5. Reniera velamentosa Armauer Hansen, The Norwegian North-Atlantic Expedition XIII, 4, Tab. I. fig. 10, Tab. VI, fig. 3. Formed as erect leaves of an irregular shape, most frequently triangular or somewhat cordate, that is to say, narrowing belozv and with a curved upper edge, sometimes of an irregular, very obliquely cut off and compressed calicular fortn. The surface rather smooth. The dermal membrane with a Speculation of irregularly spread spicules forming here and there an irregular net. Oscula numerous. small, chiefly confined to one side. The skeleton consists of fibres, f owning an irregular network, longi- tudinal fibres are especially conspicuous. Spicula oxea 0'^8 — n-M""". This sponge is formed as lamellfe of different forms and thicknesses. Most frequently the form is somewhat triangular with a curved upper edge and the sides converging downwards; they seem to have been attached by the lower part, but here they have been broken off. The largest of the specimens, whose form is irregular, has a height of i6cm, a breadth of I4cm, and a thickness of ca. 4cm. Besides the more or less regularly formed lamella?, there are found in the material some fragments, a few of which seem to suggest that the lamelke may be drawn out to a stalk down- ward. Two of the least damaged specimens are of an irregular, very obliquely cut off and compressed calicular form, and have certainly had a short stalk; this form is, perhaps, the normal form of the sponge. These two specimens have a height of 9 — iocm, a breadth of 8 — o,c,n, and the wall has a thickness of 1-5 — 2"". The surface is rather smooth, but has more or less conspicuous, irregular folds and swellings. The colour (in spirit) is dirtily grayish brown or brown. The dermal membrane is easily separable from the tissue below, and is provided with a rather close spiculation of irregularly spread spicules forming, however, here and there an irregular net. Oscula are present in great num- bers, they are small, round or oval, of a size of from ca. T2mm down to cr*,mm. Most frequently the dermal membrane surrounds the oscular aperture as a little, higher or lower cone; in some places oscula are close-set in groups, in other places spread. The pores are situated in the dermal membrane in the intervals between the spicules, sometimes very close-set; their measured sizes vary between 0-023— o-i7mm. As in many leafshaped sponges, oscula seem also here to be found chiefly on one side of the sponge, and the pores on the other, but this feature is, however, far from being strictly carried through; on the side chiefly provided with pores, groups of oscula and spread oscula may be found, and on the other hand a few pores may be seen on the oscular side. The fibres of the skeleton are rather well marked, and form an irregular network; longitudinal fibres are especially marked, and may reach a considerable thickness and firmness. Spicula are oxea, they are evenly and rather gradually tapering, but not to so high a degree as in H. panicea; they are slightly curved or more rarely straight; the length varies between 0-58— o-8ram, but is most frequently ca. 075""" with a thickness of o-oi7mm. Shorter and finer oxea are only seen singly. A few styli are found, which seem especially to occur in the dermal membrane; in this strongyla may also be found quite singly. As I have had a piece of one of the specimens of Armauer Hansen, I have been able to PORIFERA. 1. j. determine the species with certainty; without a comparison with an original specimen an identifying would have been impossible, as the descriptions, as well with regard to this species as to the other species established by Armauer Hansen, are exceedingly short, and the figures of the spicules very incorrect and not to be recognised. Locality. From stations 53, 95, and 96 we have some rather well preserved specimens; : stations 21, 27, 2f. this species we have four specimens, all rather cylindrical, of a length of 7,-t, — 4-'" and a diameter of 10—14"""; they are, however, all broken off at the lower end; one specimen seems to have n account of its clearness and the small amount of it. Spic/t/a are comparatively thick, somewhat curved oxea; they are almost of equal thickness in their whole length, are abruptly pointed, and the point is bounded by rather straight lines, so that they approach tornotes in form. The bending may be more or less pronounced, but the} are rarely straight; most frequently the bending makes an even curve, sometimes, how.ever, it is rather sharp. The size of the spicules is very constant; the length is between 0-41 0-447 ""5 tne>' ,nav ^ a little shorter, and may also reach a length of up to 0'52mni, in one specimen especially they often reach a length of <> - The thickness most frequently is o-023mm, DUt ma>' als0 De a ntt'L' 1(-'ss- Spicules being to a consider- able degree shorter and finer than those mentioned, are very scarce. As I have had before me one of the specimens of Armauer Hansen, I have been able to determine the species with certainty; the specimens of Armauer Hansen are somewhat larger than those described above; they have a height of 5cm, and a diameter of ca. 2-5cm, as may also be seen from the habit-figure cited (PL VI, fig. 2), but otherwise they are of the same form; the specimen I have- seen, was likewise broken off at the base. Locality: Of this species we have three specimens from East-Greenland, obtained by the 1 Greenland expedition 1N91— 92 in the following places; 72 24' Lat. N., ro, 42' Long. W., depth ca. fathoms, two specimens; the south-end of Jameson's hand, depth 10 — 60 fathoms, one specimen, and further one specimen, taken on 63" 15' Lat. X., 9 35' Long. W., depth 270 fathoms (Wandel). Geogr. distr. East-Greenland and west of the Faroe Islands; with regard to the specimens of the Norwegian North-Atlantic expedition the station is unknown. On station 85, 63° 21' Lat. N., 25 21' Long. W., depth 170 fathoms, station 89, 64 45' Lat. X., 27 20' Long. W., depth 310 fathoms, and station 07, 65 28' Lat N., 27 39'Long.W., depth L50 fathoms, the Ingolf expedition has taken some fragments and a little specimen, which, I think, must be referred to this species. The whole specimen has a height of ca. .:> > ' , and also the fragments seem to have belonged to small specimens. As to outer form and skeletal structure they agree completely with the typical specimens, and also the form of the spicules is the same; on the other hand the spicules ol these specimens are a little smaller, the length varying from 03b1 quite down to 0268 ". while tin thickness is about 0-014""". I'1 spite of this rather considerable difference in the size of the spicules, I feel obliged to refer the specimens to this species, as the othei structures show no difference, and we also in the typical specimens max find spictdes of a length not exceeding 0*36 One specimen has further been taken at station 64, 62 06' Lat. N., 10 00' Long. W., which 1 must also refer to this species. It is of a similar size as that of the typical specimens, but is irregu- larly flattened; in all other respects it is of quite the same structure, onh the skin i- somewhat iucrusted The Ingolf-Expedition \ 1 i PORIFERA. L ::::t~. -: ■ - : :~ "t : '- -- - - .-■-.- . : I " - ■ :•; ~tra :: :: :■_- " i": z~zzh :: :_i^~:; iz.2 ger and thinner than in the : :-. : • •:;. : -■..--.:■. v : : : - • : : . . . . -. - " ' " . . . . - -fieri : : ""■_"- . _ : loose, irreg- eton, only consisting of po" - - ..;-;: . -.r. :: H • : r .- : .::. r. z: r. - - - .a - •-."■_ : : ~ '.:. -t - .-■-.. ■ >-i -. -. - H. tenuidcrma - • PI X. Figs :— : '■ma/ ' ' ' ' ." :u£ar met, one specimen, plate- or cnshie:- of a Buccttt dfc has a j i - : - - - : s gn - - - "-- ■ - - - - i . ; : rs. 7':- : - : ~ .:.-;. : •. : : ~t~- : --. - - t :::_:'. : :: - - : - i~- e a diameter of np to t been obs - - - ~ti r: t : r : - . ".--■- _ - : Hiring m crt or less . - PORIFERA. I Spicula are slightly curved or, rarely, straight oxea, with very evenly, but not exacth tapering ends. The length varies from 0-33— o^""1, but appears to he most frequently towards The thickness is quite constant 0-013— o-oi57'nm. Shorter and liner spicules are seen quite singly. Locality: Station Si, [,i 44' Lat N., 27 00' Long. W., depth 485 fathoms, one specimen. On account of its distinct primary fibre- that support a dermal membrane without spicule.-., this species like the preceding one belongs to those species of Halichondria approaching the Reniera. 8. H. colossea n. sp. PI. Ill, Figs. 1—2, PI. X, Figs. 3 7. Of an irregular caliatlar. somewhat compressed form. The sue the outside of tk mostly smooth, but the upper surface and that of the caliatlar cavity shaggy from projecting shier The skin provided with closely packed spicules of the smaller form, running parallel to the si where the skin is shaggy, this layer is pierced by projecting large spicules. Oscula are pound in the caliatlar cavity. The skeleton consists of closely packed needles, and is -without fibres; consequently the consistency is firm and hard. Spicula oxea varying in length from ot^""" to about j""" : they divide into two, not sharply distinct, groups of sizes, of which the smaller are found in the skin and on the membranes of the canals. The only specimen in hand of this species i- very large and of an irregular, somewhat com- pressed calicular form. To be sure it cannot be decided with certainty, by which part the sponge has been attached; but probably the calicular cavity has been turned upward, and the sponge has be attached by the opposite part. The specimen has a height of 301""', a length of 50 \ and a breadth oi 25 . The cavity has a depth of about 14- and a breadth of about S ', and. as shown b\ the picture pi. Ill, fig. 1, is lying somewhat in one side of the sponge. The surface has irregular, flat depi and folds, but on the outside of the sponge it is otherwise mosth rather smooth; on the uppei side and in the calicular hollow, on the other hand, it is provided with projecting spicules, so that here it appears shaggy. The colour (in spirit! is gray-brown. On account of the needles that an packed throughout the sponge, the consistency is firm and hard. The dermal membrane is only with difficulty to be separated from the tisstie below; it is provided with closelying spicules parallel to surface. Oscula are found in the calicular cavity; they are rather large and very irregular, the la:. part of the walls and bottom of the cavity being occupied b\ oscula and Ids betv. them, and the\ pass so gradually into the wide canals, that no distinct boundary is I und be- tween osculum and canal; strictly speaking the cavity is a large groove, divided into small passing at last into the system of canal.-. Also outside of the calicular eavit\ smallei with oscula may be found on the upper surface. In spite of an examination of several stained pi< of the dermal membrane, no pores have been found: on account of the dense spiculation of the mem- brane they are perhaps onl\ found in particular places The skeleton consists of an exceedingl) dense tissue ol needles lying without any order among each other in every direction. The dermal membrane is provided with a ven dense spiculation; the needles lying side by side in even dii arallel to the surface, but in such a way, that the\ situated in groups in which the spicule- are parallel to each other ( pi. X, fig. | I. These spicules are all PORIFERA. I. small, up to a length of o^"11", and thus they belong to the smaller of the spicules occurring in the sponge. The skeleton consists otherwise of large and small spicules lying without any order among each otherineverj direction, and very closely packed. No fibres are found. The spicules are most closely packed towards the surface, which is, accordingly, very hard. Where the surface is smooth, the large spicules inside of the dermal membrane are seen, in a section perpendicular on the surface, to be arranged chiefly parallel to this (pi. X, fig. 6); where, on the other hand, the surface is shaggy from the project- ing spicules, the section shows these, which are all large, to be arranged more or less perpendicularly on the surface and piercing the dermal layer of small spicules also present here (pi. X, fig. 7). The -\ stem of canals is lined by a membrane, provided with spicules of the same size as those of the der- mal membrane, but they are not here so closely packed (pi. X, fig. 5). When the dermal membrane is examined over the edges of the oscular openings down into the canals, all degrees between the more or less close packing of the needles are found, the spicules in the membrane becoming more and 11K He spread. The larger canals are comparatively few, and their chief direction seems to be perpen- dicular through the sponge from the supposed base to the oscular openings of the upper surface. Spicula are oxea, slightly curved in the middle and exceedingly long and evenly tapering from the very middle to the ends; their sizes are exceedingly varying, from 0-14 — 2'02mm. The middle sizes are scarce, and thus the spicules convey the impression of occuring in two groups of sizes. In the smaller ones the bending is not so distinctly in the middle as in the larger, but they are more evenly curved. Thus the way in which the spicules occur in the sponge, is in this species about the same as in //. genitrix, the small oxea partly occuring throughout the tissue, partly forming the spiculation of the dermal membrane and the membranes of the canals; but contrary to the case in //. genitrix, the spiculation of these membranes is here exclusively formed by the smaller oxea without any ad- mixture of the larger ones. Topsent (Resultats des Campagn. scient dti Prince de Monaco, Fasc. II, 66, pi. IX, fig. 3) de- scribes a new species, //. pachastrelloides, which, as to the form and varying in length of the spicules as well as the firm consistency, agrees with the present species, but the largest length of the spictdes is stated to be i^"1"1, and the common length o-g3'nm. The species of which only one specimen is known, grew incrusting on a stone. On account of the stated difference in the size of the spicules and the fact, that Topsent does not at all mention that the smaller spicules form an outermost der- mal layer, the present species must be different from pachastrelloides , although it is surely nearly allied to .it. Locality: Station 90, 640 45' Lat. N., 290 06' Long. W., depth 568 fathoms, only one specimen. 9. Halichondria? difficilis n. sp. PL II, Fig. 7, PL X, Fig. 8. Of a very irregular, most frequently tuberous or lobate form. The surface smooth. The outer- most /aver forming a dermal layer with closely packed spicules more or less parallel to the surface. The skeleton consists of irregularly spread needles, not closely set. Fibres are not formed. In the skeleton rusted a great number of extraneous bodies. Spicula oxea 0-06 — o'jj""". PORIFERA. I. This species is of a very irregularly lumpy or lobate form; deep grooves or fun be Found, and projecting lobes seem sometimes to coalesce, so that narrow hollows ma\ arise, stretching far into the sponge. The largest specimen has a length of ca n and a breadth oi 'he smallest specimen that is of a roundish form, is ca. 4"' long In a breadth of hardh v" Among the smaller specimens one is of a depressed form with irregular deep furrows in the edges, anothei is limned like a rather long staff, strongly and irregularly curved, of a length of about 7"". Whether the sponge has been attached or not, is not to be decided with certainty from the specimens in hand; most ..1 them, to be sure, are somewhat damaged, pieces being broken off, and thus they might be supposed to have been broken off at the place of attachment; most things, however, favours the belief that the sponge has not been attached, or only loosely stuck into the bottom; neither is the upper or lower surface to be decided. The colour (in spirit) varies from dirtily dark gray or bluish gray to black violet; 111 the interior it is dirtily gray. Such is the colour in most specimens, but in a couple oi instances it is differing; thus one specimen is grayish white, but has distinct remnants of the violet colour, and another is brown gray. Whether the more or less black violet colour is the original self- colour of the sponge, or it is clue to the fact that the colour has altered in the spirit. 01 the sponge lias been discoloured by lying in spirit togethei with other sponges, is now hardly to be decided. That it is the original colour of the sponge is indicated by the fact that it is most strongly pronounced in all the furrows and grooves, where the surface has not been exposed to being scraped. If in such places we cut off a thin layer of the skin and examine it under the microscope, we shall see, above the dense layer of spicules of the skin, remnants of a violet-coloured, exceedingly thin and transparent membrane, mostly wanting in the places where the colour is less pronounced; these remnants probably are remnants of the epidermis of the sponge. The consistency is rather firm, fleshy ami somewhat elastic The surface, as has been mentioned, shows some larger and smaller grooves and folds, but is otherwise smooth. The outermost layer of the sponge is marked off as a dermal layer of a thickness of ca this layer has its origin from the fact that the spicules here are closel) packed; they are lying in all directions, often, however, in such a way, that they are arranged somewhat like bundles, the spicules which are parallel to each other; in some places this disposition may pass into a partly band-shap arrangement; the spicules are chiefly arranged parallel to the surface, only a smaller numbei obliquely or perpendicularly on the surface; sometimes, however, some projecting spicules may be found, but that, perhaps, is due to the contraction of the skin. Oscitla have not been observed in tin ens in hand. The pores seem in most places t<> be rather scarce, onh here and there the} are seen in closely gathered in greater numbers; in such places the spicules in the skin max show a coarse, net- like arrangement, which, however, is only seen under the microscope. The sizes ol the pores have been measured from 0-03 0-51 ; often they do not go perpendicularly through the skin, but mow less obliquely, and consequently they are easil) overlooked, when the skin is examined from al>" the) continue as fine canals without any formation of larger sub-dermal cavities, but some oi them max branch off under the skin as horizontal canals. If a piece of the dermal lavei is cut off and exa- mined under the microscope from the inside, ,1 rather large number of canals are seen to be cut through; when in such a case no pores are seen 1>\ an examination of the outside oi the piece, the lad is, I suppose, that they are closed, or they cannot be seen on account .'I their oblique direction. The mentioned ,0 PORIFERA. I canals vary in size up to ca. cr5""". As separate oscula are not seen, we have here probably both the incurrent and the excurrent systems of canals, so that the larger canals and pores are the excur- rent ones. The skeleton. Resides the above mentioned closely packed layer of spicules found in the dermal layer, the skeleton consists of spicules spread through the tissue in all directions without any order, or sometimes arranged somewhat like bundles; here and there they may be gathered into larger numbers forming something like fibres; where they are spread in the tissue, they are not close packed, for instance not nearly so close as in H.colossea. The membranes lining the canals, have no spicules. Besides the skeleton constructed as above described, elements are found, which certainly bear a pro- minent part as skeleton, the species receiving to a high degree extraneous bodies, chiefly Foraminifera and especially sponge-spicules. Thus I have found needles of Desmacidonids, Suberitids, and of several Tetractinellids, as well as pieces of skeletons of Hexactiuellids '); they may be present in so great numbers as quite to disguise the real skeleton of the sponge. Spicula are oxea; they are slightly curved or straight, and long tapering; a few oxea may show a swelling in the middle, and this peculiarity seems to be more frequent in some specimens than in others. The spicules are very much varying in length, from o-37mm down to croS"1"1, the thick- ness varies from o-oo4m"' in the smallest ones to cvoo8nim, in a few specimens up to o-oiomm; the thick- ness is generally proportionate with the length; in the shorter spicules the tapering is comparatively shorter than in the longer ones. Whether the short needles are developmental forms of the long cannot be decided with certainty, but it would seem rather probable with regard to some of them, and the very few spicules that were finer than the given measures, belonged also to the short ones; some of the short spicules, however, and especially the very shortest ones are scarcely developmental forms, to judge by the proportion between length and thickness. This sponge shows a peculiar tissue of a vesicular structure; it consists of round, more rarely a little oval cells, lying close together with a comparatively slight intercellular substance. The cells have an average size of ca. croimm. They stain rather slightly in fuchsine, and frequently show a little, more strongly stained calotte in one side, where perhaps the nucleus is found. It is no doubt a consequence of this structure of the tissue, that the sponge by drying up contracts very strongly to an unrecognisable mass, almost as hard as bone. Also the specimens kept in spirit convey, espe- cially on account of their dermal layer being in many places wrinkled and folded, an impression of being somewhat contracted. Locality: Station 78, 60° 37' Lat. N., 27' 52' Long. W., depth 799 fathoms, four specimens and some fragments; station 90, 640 45' Lat N., 29" 06' Long. W., depth 568 fathoms, two smaller specimens. Note. I have not thought it justifiable with certainty to refer this species to the genus Halichondria, to which genus it would have to be referred by its spiculation and skeletal structure. It is no doubt very closely allied to Halichondria nigrocutis Cart. (Amorphina Carter, Ann. Mag. Nat. Hist 1886, Ser. V, vol. XVII, 50, 2. - Halichondria? Dendy, Proceed. Roy. Soc. Vict. 1895, vol. VII, 239) '! Hotli the stations, 7S and 90, on which the species was taken, gave exceedingly rich earnings of sponges, especially many Tetractinellids, among which accordingly the species must have grown. PORIFERA. I. from South-Australia; the spicules of this species are said b) Carter to divide into two groups of a length of respectively o-i— o-i3mra and cry^S"'"; and a thickness of o-oo6 ; these measures, as we have seen. agree very well with those of the spicules of the present species; the only difference is that the spi- cules are said to divide into two groups, of which the smaller cue should Ik- chiefly found in the >kin, while in the present species spicules of all intervening sizes are found, and the smaller ones enough may be found in the skin, but are not chiefly found there. Dendy describes the skin as provided with a dense feltwork of oxea , that may he arranged in a netlike manner on account of the pores, that is to say, a structure quite resembling that <>f the pit-sent species, with which, more- over, the description agrees exactly. When Dendy 1. c. supposes //. nigrocutis to be allied with cer- tain of the S'tellettinopsis-species described by Carter, it seems to me to be quite justified, which is also the case with regard to the present species1). On the other hand the species seems to be allied to Halichondria colossea and the species most closely allied to this latter one. Therefore the possibility of a relationship between Halichondria and the Tetractiuellids through Halichondria-Stellettinopsis (Coppatias Sollas), supposed by Sol las (Challeng. Report, Vol. XXV, Tetractinellida, 20X1, as also men- tioned by Dendy, I.e., might be of some probability. Eumastia O. Schmidt. From an attached, thinner or thicker basal part comparatively slender papilla rise. The skeleton consists of loose, irregular fibres and spread needles. The needles slender, long tapering ax, a. 1. E. sitiens 0. Schmidt. PI. IV, Figs. 1 — 6. PI. X, Figs. 9 — 12. 1870. Eumastia sitiens O.Schmidt, Grundziige einer Spongienf. des atlant Gebiet 42. PI. V, fig. 12. ^.S;. — Fristedt, Vega Exp. vetensk. Iakttag. IV, 426, PI. 24, fig. 13, PI. 27, fig. 11. 1896. — — Lambe, Sponges from the Atlant. Coast of Canada. Transact. Roy. Soc. Canada, Ser. 2, II, Sect. IV, 182, PL I, fig. 1. The term different, often mure or less irregular. From the attach standing. slender, iinbranched or slightly branched papilla!, some oj which bear oscvla. The surface smooth. The dermal membrane is on the papilla; provided with a reticulation oj spicules. 'The skeleton consists hires and numerous spread spicules. Spicula slender, long tapering oxea ca. o-j6—/,Hm. This species has a rather constant form; the nethermost part is expanded on the substratum, and from this part slender, close-standing papillae rise. In its most regular form it is of almost equal extent in all directions, but it may also be more expanded and become somewhat more irregular, and the comparative development of the lower part and the papilla- may also be somewhat different. The largest specimen has a largest extent of ca. i.sc'"- The other specimens vary in size from ca. 2 ca. 7cm. All the specimens have been attached; the largest one has grown round the stalk and root of a Laminaria; most of the others are either attached to shells oi Pecten and living specimens of Pecten {Pecten islaudicus Mull.) or on Balanoids; a single one is attached to an old anchor. The ') By the boiling of the spicules <>i thi I have in sevei : I regard it. however, t" bi quite sure, that these asters that have only been found quite singly, are - lies. PORIFERA. I. papillae are more or less close-standing, always, however, rather close; they are slender and slightly conical, decreasing in thickness upward, and they are nnbranched or slightly branched. They may otherwise he rather different with regard to length and thickness, and there may be some difference in individual specimens. The papillae are stubby at the summit and apparently closed, or thev may be tapering and show an osculum. The colour (in spirit) is white and somewhat transparent, in some specimens with a slight yellowish red tint. In the middle of the transparent papillae is seen an opaque whitish part. The consistency, especially in the lower part of the sponge, is rather firm. The surface is smooth, without projecting spicules. The dermal membrane is thin and transparent, but rather solid, and may easily be torn off to some extent; it is provided with spicules forming in the upper part of the sponge and especially in the papillae a beautiful reticulation of fibres. The reticulation mav, with regard to the width of the meshes, be somewhat different in different individuals. Towards the base of the sponge the reticulation disappears most frequently, and passes into another arrangement of the spicules, which are here lying close-packed in all directions in several layers, but parallel to the sur- face. In the papillae the meshes are of the largest size, and here some of the fibres of the dermal reticulation have a marked longitudinal direction. The pores are found in the meshes of the dermal reticulation, often so close as to reduce the membrane to a network. The sizes of the pores are measured from 0'02 — o-imm. They are chiefly found on the papillae, and here very close, but thev are also numerous on the other parts of the surface of the sponge, where nets of spicules are found in the skin; on the other hand they are wanting or only found in very small numbers on the lower part of the sponge where the spicules of the skin is close-packed. In the specimens examined thev appeared to be largest on the papillae, and to become smaller lower down, and the few pores found, where no reticulation was present, were very small. Oscula are found in the ends of some of the papillae; then these papillae are conically tapering, and the spicules are here arranged parallel to the longitudinal axis of the papilla and close together, and thus one of their ends is turned towards the oscular opening. The structure of the papilla. The structure of the papillae of this species has never been exactly examined. Schmidt, however, mentions that they are hollow and thin-walled, and that a fibre goes from the skeleton into each papilla, in which it radiates in an irregular wav. Fristedt says that the inner structure is very characteristic, but does not enter into further details as to these characteristic features. - The papillae are of two different kinds: pore papillae, and oscular papillae. Commonly they may already be distinguished by their outer appearance; the pore papillae, at all events their upper parts, are more slender and rounded at the top. Through their middle stretches a power- ful fibre from the skeleton, from which pillars branch off to the network of the skin, supporting the skin; the hollow of these papilla* is a continuation of the subdermal cavities spread over the whole surface, and the papiilae are abundantly provided with pores leading into the hollow. The oscular papillae most frequently are somewhat thicker than the pore papillae, and at the top they are, as has been mentioned, conically tapering, and end here with an osculum ; and in this tapering part the spi- cules are King close together parallel to each other and with one end turned towards the oscular opening The papilla is hollow and thin-walled; also here a fibre from the skeleton stretches up into it, but this fibre runs along the wall, and most frequently it disappears in the uppermost part of the PORIFERA. I. papilla. If the wall is examined, it is found to be abundantly provided with pores, and so it would be an obvious conclusion that these pores are leading directly into the oscular canal. A closer exami- nation shows, however, that the oscular papilla is double-walled, or, in other terms, that the subdermal cavities continue over the oscular papillae. These subdermal cavities are oftenest narrow, so that the wall without any closer examination may convey the impression of being single. Where the fibre passes into the oscular papilla the subdermal cavities are somewhat wider, and the fibre runs in the partition-wall between the oscular canal and the subdermal cavity, so that in a transverse section the large oscular canal is seen with some smaller cavities around it, which are subdermal cavities; some- times these cavities are so large, that it cannot be seen immediately in the section, which of the cavi- ties is the oscular canal; generally, however, the oscular canal is seen in the transverse section to be lying at one side and the subdermal cavities at the other, and to be arranged in such a wax, that the outer wall and the partition-wall form two excentric rings, one within the other (PI. X, fig. mi. The partition-wall is a thin, transparent membrane, not as the dermal membrane provided with a network, but supported by brauch.es that from the fibre bend regularly into it; besides a few spicules are found spread in it. I have not been able to decide with certainty, whether the oscular papilla is always double-walled through its whole extent, that is to say, whether the subdermal cavities stretch quite round the oscular papilla, and perhaps some difference may be found in different papillae with regard to this feature; if they go quite round, they are at all events most frequently very narrow on the sid< of the papilla opposite to the fibre. Besides the structure as here described, which is the plainest form, complications may occur; thus the pore-papilla and the oscular papilla may be united into one papilla, so that one osculum or a couple of oscula may be found more or less far down the side of the pore papilla; this fact alters nothing in the inner structure of the papilla, and otherwise the relation between the oscular canal and the subdermal cavities may be somewhat varying. It would seem that more or less complete partition-walls may also be found in the pore papillae, and finally the possibility is not excluded that in many of the papillae appearing as pore papillae, an excurrent canal may he- found, although for the present there is no visible or functionating osculum. The skeleton. Besides the dermal skeleton and the skeleton of the papillae mentioned above, the other skeleton of the sponge consists of some loose fibres and between these numerous and rather close-set spicules, lying in every direction without any order; the fibres have a somewhat irregular course, but chiefly they run from the base towards the surface; all the largei canals have the same direction. The fibres may in some places be closer than in others, and be gathered almost as bundles; they are rather thin, their thickness not exceeding 0-09 , while tin- fibres of the papillae may have a thickness of up to i"5mm. Spicula are oxea; they are very long tapering, almost from the very middle, and most frequently they are slightly curved; the curve may lie even, but is often a more or less sharp bend in the middle, so that the spicules are quite like those of Halichondria panicca, but the} reach a considerably greater length than is common in this species. The length varies from ca. 036 0S1 . the thickness, which is not always largest in the longest spicules, varies from <> have a dermal membrane without spicules, resting on the underlying skeleton and pierced l>v the ends of the primary fibres, while the Halichondria-STpecies have most frequently a dermal membrane with spicules, through which no ends of fibres project; but also here transitions are found, as for instance in the above mentioned species Halichondria oblonga and tenuiderma, which with regard to this fea- ture approach the Reniera. Fristedt (Vega Exp. vetensk. Iakttag. IV, 425) calls attention to a similar fact, and mentions Halichondria (Atnorphina) renieroides as also approaching the Reniera in this respect. In this species, however, it is not the ends of fibres that project, but a dense spiculation is found of spicules a little projecting and perpendicular on the surface; therefore with regard to this feature the species is not especially nearly allied to the Reniera. From the reasons given ah species with a less regular skeleton, and with exceedingly little spongin, hut with short, never espe- cially long and evenly tapering oxea, have in the present work been referred to Reniera. On the other hand R(- ///era-species, as has been mentioned under the Chalinines, may by a development of spongin approach these latter in skeletal structure, so that no sharp limit can he drawn. 1. R. urceolus Rathke et Vahl. PI. I, Fig. 6. PL XI, Fig. 1. 1806. Spougia urceolus Rathke et Vahl, 0. F. Miiller Zoologia danica IV, 42, Tab. CLVII, fig. 3. 1870. ?Chalinula robustior O.Schmidt, Grundziige einer Spongienf. des atlant. Gebiet 38. Oblong-pyriform. stalked, sometimes branched or showing several coalesced lubes. The dermal membrane thin, without spicules; the rials 0/ the fibres projecting and the su shaggy. In the upper end a large osculum leading into a wide oscular canal running thi The skeleton a rather regular network of primary and secondary fibres with quadratic no unispicular. Particular polyspicular fibres are found running from the stalk longitudinally through the sponge. Spicula comparatively thick, slightly curved oxea. , ""'. This sponge of which we have two whole specimens and some mor< damaged fragments, is in its most regular shape oblong-pyriform, and is below produced into a short stalk, by which one specimen is attached to a little stone, while the other is lorn oil. The largei and more lengthened specimen has a length of uocrn, and a greatest breath in the middle of 3cm. The other specimen is smaller and comparatively less lengthened; it has a length of 7' , and .1 greatest breath ol 'hie 36 PORIFERA. I. of the damaged specimens consists of four coalesced tubes, two of which are of equal length, while the two others are shorter; the height of the specimen is 6o'nm, but the lower part, probably a rather long piece, is wanting. Whether we have here a ramification, or separate individuals growing near each other and then coalesced, cannot be decided; it is perhaps more probable that it is a ramification as the oscular canal of one of the small tubes runs into that of the large tube. The consistency is soft, but not, however, very fragile. The colour (in spirit) is grayish yellow. The surface is finely shaggy from the projecting ends of the fibres protruding to the length of a spicule. The dermal membrane is thin and without spicules, it is supported by the underlying skeleton and pierced by the ends of the fibres, and it is not separable. The pores are measured of a size of 0-029— D'oSo/1™. On the top of the sponge a circular osculum is found, which in one specimen has a slightly prominent margin; it has a diameter of 5 — /mm. This osculum leads into an oscular canal continuing through the sponge cpiite down into the stalk; the canal is through its whole length of about the same width as the osculum, only in the lower end it is somewhat narrowed. On the inside of the oscular canal the excurrent canals open rather close to each other, the size of the openings is about 1— 21 2mm; no special arrangement of the openings is to be traced. The system of canals is highly developed, and the sponge very cavern- ous. The chief canals have otherwise a very regular course, all beginning from the base or from a spot near the outside, and running parallel to each other arcuately upward and inward towards the oscular canal; consequently all the openings in this canal are turned upward, and therefore in a longi- tudinal section of the sponge a certain concentricity due to the course of the canals, is seen. All over the outside of the sponge below the surface small, roundish subdermal cavities are found, which by being seen through the skin, give the sponge a netlike appearance. The skeleton consists of a rather regular net ot fibres forming meshes, most of which are quadratic, but some may also be triangular or pentagonal; by far the greatest part of these fibres are unispicular. Of the fibres those only, running from the middle of the sponge towards the periphery arcuately upwards (the primar}* ones), are distinct and complete, while the fibres running at a right angle to the former ones, and thus more or less parallel to the surface, are indistinct and incomplete. A certain relation between the canals, at all events the chief canals, and the skeleton cannot here be overlooked; for, the larger canals, as before mentioned, running upward and inward, while the skeletal fibres are running upward and outward towards the periphery, these primary fibres will always be at right angles to the canals, while the spicules of the secondary fibres are partly parallel to the canals. Besides the fibres forming the net of meshes, some comparatively thick, polyspicular fibres are found; they begin in the lower part of the stalk, which is almost exclusively formed by such fibres, and then they radiate up through the sponge branching off. The needles forming the net of meshes, are at the ends united by a distinct mass of spongin. Scattered in the tissue some needles smaller and finer than those forming the skeleton, are found, but only in small numbers. Spicula are oxea, rather thick and only very slightly curved; their length is rather constant, on an average o-2o8'nm, but varying a little to both sides, and may go down to o-ijS""", the thickness varies between o-oi6 and 0'0i2mm, the shortest ones being commonly the thickest; as before mentioned mall number of shorter and finer needles are found, but they are by transitional forms evenly connected with the others, and so they may certainly be regarded as developmental forms. PORIFERA. I. ,- Of the smaller fragments one is a specimen, the lower part of which is wanting; it is much smaller than the specimens mentioned above, the length being 21""", the breath i}1"1' ; the osculum is 4mn\ Further may be noted that the spicules of this fragment are a little smaller than those of the larger specimens, their length being on an average cno/""1, and their thickness cm 12""". The determination of this species as R. urceolus may no doubt be regarded as certain; to be sure, the description cited is very short, but as well the description as the picture agrees very well with the present species; the description cited is by Rathke, and the plate by Yahl, and consequently O. F. Miiller cannot be cited as the author of the species. Johnston (British Sponges and Lithophvtes, 1842, 175) supposes Spongia urceolus to be a variety of Gran tin compressor but already the size and also the form show that such cannot be the case. Chalinula robustior which, with a query, 1 have referred to this species, was established by Schmidt I.e. on two small fragments from Iceland, found in our museum. The examination of these fragments has shown that their spicules agree completely with those of the present species, and I think it rather sure that they are stalk-pieces of A', urceolus. The polyspicular longitudinal fibres that are rather well developed in the stalk, have been the cause why Schmidt has thought to have to do with a Chalinine. Locality: Iceland, two whole specimens (Steiucke); Eastern Iceland, depth 38 fathoms, a little specimen (Horring); the northern coast of Iceland, depth 52 fathoms, a fragment (Wandel); the Faroe Islands, 6 miles to the northwest of Kalso, depth 60 fathoms, one specimen (Th. Mortensen). From Jacobshavu in Greenland (assistant Olsen) we have three specimens, which I take to belong to this species. They grow on the roots of a Laminaria; with regard to the form and size of the spicules and the structure of the skeleton, they quite agree with R. urceolus, but the two specimens have no definite form, and are incrustin,^; they are rather small, their greatest length being ca. 2< the third specimen, on the contrarv, forms a pyriform tube like the form of urceolus; this specimen has a height of 20""". Whether these specimens be really R. urceolus, I cannot decide with certainty; but if so, the small incrusting specimens are presumably quite young, and the species cannot be sup- posed to rise to a tubulous form, until it becomes older; in reality the three specimens in hand form a characteristic series: the first specimen is absolutely incrusting, and has a greatest height of 6 . the second rises from an incrusting plate to a semiglobular cushion, and lias a height of 10''"", neither of these specimens show any osculum; the third specimen rises to a short-stalked tube of a height of 20mm with an osculum on the summit. Geogr. distr. In the place quoted from Zoologia danica, the species is mentioned from northern Norway. 2. R. parenchyma n. sp. PI. VII, Fig. 1, PL XI, Figs. 2 |. Erect, lea/shaped, oblong-oval. Tin dermal membrane thin, without spicules: the cue /ibres projecting, ami th, surface consequently finely shaggy. Oscula small, only occurring on one 1 The skeleton a regular network 0/ primary and secondary fibres, the fibres unispicular. Particular / spicular fibres arc found running longitudinally through the sponge from the base. Spirilla slightly curved, sharply pointed ox, a. ca. 0'2j8mm. PORII'KRA. I. This species is erect, and forms an oval leaf narrowed below at the place of attachment. The height is iSCI", the breadth has been ca. iocm (the specimen is somewhat damaged), and the thickness of the leaf is in the middle ca. 4"", but it becomes somewhat thinner towards the edge which is rounded. The leaf is slightly arcnate from the middle towards the edge, so that one side is somewhat convex, the other somewhat concave. The consistency is soft and flexible. The surface is everywhere finely shaggy from the projecting spicules. The dermal membrane is thin, transparent, and without spicules, it rests on the skeleton below, and is pierced by the ends of the fibres; accordingly there is no special dermal skeleton. The colour (in spirit) is almost white, and the sponge is rather transparent, only the longitudinal fibres are at the base seen to be yellowish. (The sponge is from a considerable depth, and a large part of the tissue has probably been destroyed or quite washed away by the hauling up). Pores are found rather densely on both sides as round openings; they are very much varying in size, from 0.029 — o-23mm. With regard to oscula it has not been possible with certainty to establish their behaviour, as the skin of the sponge only in few places is undamaged, and I have not been able po- sitively to decide, whether they are to be found on both sides or only on one of them. In the skeletal net cylindric holes or canals of a diameter of 0-5 — 1™ are seen, lying rather close to each other; they go in a horizontal direction almost through the whole sponge. If the sponge is viewed under a magnifying glass, the oscular canals are seen to shine through on both sides, but they appear on both sides to be closed by the outermost net of spicules; according to this we should have to suppose that the oscular openings are found on both sides either as one or as several pore-like openings for each oscular canal; in this case there would be no difference of size between the largest pores and the oscula. If, however, the layer of the skeleton closest to the surface is cut off on both sides and examined, we shall here find a little difference between the two sides of the sponge, one side showing openings in the net; these openings are situated over the oscular canals; I have not seen them surrounded by the dermal membrane as distinctly limited oscula, but this I take to be due to the fact that the skin of the specimen is not undamaged. In the specimen in hand these openings are situated on the convex side. If they are the oscular openings, these openings are thus exclusively, or at all events almost exclusively, found on one side of the sponge, and considering the fact in the two following species there can scarcely be any doubt that they are oscula. The skeleton forms a rather regular network with more or less rectangular or cubic meshes. It consists chiefly of fibres running from the interior of the sponge arcuately upward and outward towards the surface, which they meet at about a right angle. Accordingly the fibres spread in a fanshaped manner both towards the surfaces and the edges of the sponge. The skeletal tissue forming the inner or middle part of the leaf-shaped sponge, is, on account of this structure, less regular than the part towards the surface. The mentioned fibres are unispicular; they are connected by spicules that are more or less at a right angle to them, and only form incomplete fibres, which accordingly run rather parallel to the surface. The first mentioned fibres pierce the surface to the length of a spicule, and consequently the surface is finely shaggy, and there is, as has been mentioned, no parti- cular dermal skeleton. Besides by this regular skeleton, the sponge is also supported by thicker, poly- spicular fibres which from the base, where their thickness is greatest, branch up through the sponge; they run as well in the middle plan of the sponge as towards the surface often crossing each other, PORIFERA. I. the fibres near one surface having another direction than those near the other surface; upon the whole their course is rather irregular. In the nodes the skeleton is united by a clear, slightly yellowish mass of spongin; in the polyspicular fibres the spicules are arranged in bundles, so that tin- ends of spicules lying alongside of each other, are in the same place; accordingly the spongin uniting these ends, form yellowish transversal bands across the fibres. Spicula are oxea, sharply, almost hastately pointed, with a fairly long point; they are slightly and evenly curved or more rarely straight; a characteristic feature is that most frequently they a: little thinner in the middle than towards the ends, by which the pointing becomes more hastate. The length is rather constant ca. 0'238mm, deviating a little to both sides; the thickness varies between 0009 and o-oi2mm. Locality: Of this beautiful species, so characteristic as well by its exterior as its spicules, we have one specimen, not quite complete, from station 91, 64" 44' Lat. N., 31 00' Long. W., depth 1236 fathoms. From station 36, 61 50' Lat. N., 56°2i'Long. \\\, depth 1435 fathoms, and station 73, 62 58' Lat. X., 23 28' Long. W., depth 486 fathoms, the collection contains some small specimens, which I dare not with certaintv refer to the present species; they agree with this with regard to the form and size of the spicules, as also with regard to the main features of the skeletal structure; only the oscular canals seem to be less marked; but as these specimens, which are considerably smaller than the described one, are surely young ones, this difference may perhaps be due to this fact; therefore I think it probable that they belong to this species. — From station 89, 64-45' Lat. ^T-> 27 2°' Long. YV., depth 310 fathoms, and station 105, 65 34' Lat. X., j^i' Long. \V., depth 762 fathoms are further found a few small fragments of the same skeletal structure as parenchyma, but the spicules have most frequentlv a length of ca. o-26mm and a thickness of cvoii""n; thus they are a little longer than in the specimen described, but otherwise they are of the same form, and as the spicules of parenchyma nun- reach the given length, it is rather probable that they may belong to this species; the fragments, which are both basal parts, are too small to admit of a certain determination. 3. R. folium n. sp. P1.V, big. 5, PI. XI, Fig. 5. Erect, irregularly lea/shaped, the leaves may be irregularly coalesced. The dermal membrane is thin, without spicules; the ends of the fibres project making the surface finely shaggy. Oscula small, numcr only found on one side. The skeleton forms a regular network of primary and secondary fibres ; the fibres ure unispicular. Particular polyspicular fibres running longitudinally, are found. Spicula are slightly curved, rather gradually tapering oxen. o-ig—o-2imm. Of this species there are in the collection six lamella-, which, however, are more or less damaged, and they are likely to be fragments of only a couple of specimens. The sponge is formed as ei irregularly leafshaped lamellae, which may he irregularly coalesced reciprocally, and, judging by the material, they have been attached with a broad base. The specimens in hand have a height of ca. ioo'n"\ and the thickness of the lamellae is in the middle up to 5m,n, but decreases towards the margin. The consistency is rather soft and flexible. Here and there the s has irregular, slighth projecting 40 PORIFERA. I. ridges, and is somewhat grooved; it is finely shaggy from the projecting spicules. The dermal membrane is thin, transparent, and without spicules; it rests on the skeleton, and is pierced by the ends of the fibres, so that no particular dermal skeleton is found. The colour (in spirit) is dirtily grayish yellow. The whole sponge is filled with sand to a high degree, what has, perhaps, taken place in the trawl. The features of this sponge with regard to oscula and pores seem to be the same as those, supposed to be found in the preceding species. Pores are found in large numbers on both sides, the)- have been measured to a size of from ca. 0-05 — cri7,nm. In the skeleton oscular canals are found, somewhat smaller than in the preceding species, viz. ca. o-5mm; the}- are very close to each other, and go horizontally almost quite through the sponge. These oscular canals open on one side of the sponge with apertures that are seen to be rather well bounded in the skeleton; the apertures are of the same diameter as the oscular canals; but as I have seen no osculum distinctly bounded by the dermal membrane, I cannot give the real size of the oscular aperture; the whole structure implies, however, that the osculum formed by the skeleton, is not narrowed by the dermal membrane. The projecting spicules that are situated on the margin of the osculum, project partly over it, in such a way as pictured in the following species. Thus oscula are only found on one side of the sponge; to be sure similar openings may be seen here and there on the other side, but then they seem to be due to a damaging of the surface, so that this has been broken through to the oscular canal. The skeleton of this species is constructed in quite the same way as that of the preceding one, and here are also found irregularly running, polyspicular longitudinal fibres; these may, on their wax- upward, bend out towards the sides, and thus they may go in directions very different from that of the longitudinal axis. The ends of the spicules are as usual united by spongin. Spicula are oxea, evenly and rather gradually tapering; they are slightly curved, sometimes almost straight. The length is very constant, between 0-19 og o-2imm, but is most frequently o-2o8mm; also the thickness is constant, 0-013— 0'0i4mm. Shorter and finer spicules are only seen quite singly. Locality: Station 46, 6i°32' Lat. N., 1 1° 36' Long. W., depth 720 fathoms; station 21, 58°oi' Lat. N., 44 45' Long. W., depth 1330 fathoms, a very small fragment. 4. R. ventilabrum Frstdt. PI. XI, Figs. 6-7. 1887. Reniera ventilabrum Fristedt, Vega Exp. vetensk. Iakttag. IV 420, PI. 24, fig. 3, PI- 27, fig. 8. Erect, leaf- or fan-shaped. The dermal membrane thin, without spicules; the ends of the fibres project, and so the surface is finely shaggy. Oscula numerous, small, only found on one side. The ske- leton is a 'regular network of primary and secondary fibres ; the fibres unispicular. Particular polyspicular fibres issuing from the base and running longitudinally, are found in large numbers. Spicula are evenly tapering, slightly curved oxea 0-21 — 0.25'""'. Of this sponge we have a specimen, which is all but fanshaped, increasing in breadth upward from a base that seems to have been a short stalk. The somewhat damaged specimen has a height of ca. i8cm by a greatest breath of ca. i5cm, the thickness is ca. 4mm. The consistency is rather fragile, only the base is considerably harder on account of the numerous longitudinal fibres. Here and there the surface shows slight depressions, but is otherwise even, and everywhere finely shaggy from the PORIFERA. I. projecting spicules. The dermal membrane is thin and without spicules; it is resting on the skeleton below, and is pierced by the ends of the fibres; no particular dermal skeleton is found. The colour (in spirit) is brown. The pores and oscula are as in the two preceding species, but may here be more distinctly observed; pores are found in large numbers on both sides, they have a size from o-02 — cr23'mn. Oscula are only found on one side of the sponge; they are present in large numbers, and are round openings in the skeletal net of a diameter of ca. o-5'nm; of the projecting spicules of the surface those that are situated on the margin of the oscular opening, project obliquely over this opening (PI. XI, fig. 7). The oscular opening leads into an oscular canal of the same diameter, which in a chiefly horizontal direction stretches almost throughout the sponge. The skeleton is constructed as in the two preceding species, with the only difference that in the present species there are many more and more powerful longitudinal fibres giving the sponge some firmness in spite of the otherwise rather fragile consistency. The base of the sponge con>: almost exclusively of these longitudinal fibres that are here more or less coalesced, and consequently the sponge is at the base hard and firm. The spicules of the fibres are as usual cemented by spongin, but not quite imbedded in spongin. From the base the fibres branch up through the sponge, growing thinner in their course, and most frequently several fibres run alongside and intercross in the thickness of the sponge. The other parts of the skeleton have unispicular fibres; only the fibres issuing in a fanshaped way from the middle towards the surface, mav sometimes show a couple of spicules alongside in the outermost part. Spicula are oxea; they are evenly pointed and slightly bent or quite straight. The length varies between 0-214 — 0'25mm, but appears most frequently to be cr238""", the thickness is croi2 — ceoi . This species, as will be seen, agrees, as to the length of the spicules, with R. parenchyma; but there is, besides the features given in the description, also a difference to be noted in the spicules, these being thinner in R. parenchyma than in the present species, neither are they in the latter so hastately pointed nor are they thinner in the middie than towards the ends. As I have had a piece of Fristedt's original specimen of R. ventilabrum, I have been able to decide that the form and size of the spicules, as well as the construction of the skeleton, agree com- pletely with his species, and therefore I regard the identification as sure. The only difference is that in the original specimen the oscula and oscular canals are generally a little larger than in the described specimen. The very short description by Fristedt does not afford much hold for the deter- mination; thus he does not mention that oscula are only found on one side. I do not quite under- stand his description of the skeleton; he says: not the case, these fibres are unispicular, only now and then may lie found in their outermost part a couple of spicules along- side. On the other hand he does not at all mention the polyspicular longitudinal fibres, foi it cannot well be supposed that they are meant in the first quoted sentence, as they have a quite different course. Locality: The species has only been taken in one specimen, station 28, 65 1 \ hat. X., 5 Long. W., depth 420 fathoms. Ill- [ngolf-1 xpedition. VI. i. ,2 PORIFERA. I. jr. Jish-. Frist edt has the species from Spitzbergen from a depth of 280 fathoms. Note. This sponge shows a particular feature, which I have not been able to interpret with complete certainty. On one side, the side on which only the pores are found, a large number of excrescences of a more or less regular subglobular or almost globular form are found, sometimes coa- lesced, and forming irregular bodies. The size of these excrescences is from that of a pea to that of a hazel nut. They are quite regularly constructed, fibres radiating from the place of attachment in a Fanshaped way to all sides and piercing the surface; and then these fibres are connected to a net by incomplete fibres parallel to the surface; thus this skeletal construction is upon quite the same prin- ciple as that of the sponge itself, and the skin is also provided with pores. These excrescences appear to be due to a worm (a Svllidian?); at all events one or more of these were found in holes in those excrescences that were cut through. 5. R. hyalina n. sp. PI. XI, Fig. 8. Erect, leaf-shaped. The dermal membrane without spicules; the ends of the fibres projecting, and the surface consequently finely shaggy. Oscula? The skeleton a regular network of primary and secon- dary fibres, the fibres unispicular. Particular polyspieular longitudinal fibres are found. Sficula are sligtly curved, evenly tapering o.xea, 0-268 — o-ji""". Of this sponge we have only one specimen, which is, moreover, a fragment; but as it shows characteristic differences from the preceding three lamelliform Reniera-sp&ci&s, I have thought it best to describe it. I take the fragment to be the upper part of a specimen, and with regard to the form of this specimen can consequently only be said that it is a thin lamella. The specimen in hand has a height of 2jm"\ a breadth of 48mm, and a thickness of scarcely 2mm. The consistency is rather firm, but the leaf is flexible. The surface is smooth and everywhere finely shaggy from the projecting spicules. The dermal membrane is thin and transparent and without spicules; it rests on the skeleton below, and is pierced by the ends of the fibres, so that no dermal skeleton is found. The colour (in spirit) is whitish, and the sponge is hyaline. As to pores and oscula, this sponge show's other features than the three preceding ones. No oscular canals are found here as those mentioned in the descrip- tions above; on the contrary roundish openings in the dermal membrane are found in large numbers on both sides of the sponge, varying in size between o-c>23mm and ca. o-2o.8mm. All degrees of inter- mediate sizes are found, so that it is impossible by means of the size to distinguish between pores and oscula; perhaps the larger ones act as oscula, the smaller as pores ')• The skeleton is constructed in quite the same way as in the preceding species with the only exception that no oscular canals are found in it; the polyspieular longitudinal fibres are (in the frag- ment in hand) only little conspicuous. The spicules are in the skeletal net and in the polyspieular longitudinal fibres united in the common way by a clear mass of spongin. Spicula are oxea; they are evenly pointed and slightly curved, sometimes the curving is some- what more pronounced, and then it is also sharper; the length is 0-268 — o'3i5mm, but the greatest length ■I The fragment being the upper part of a sponge, it may also be possible that the oscula have not reached so far up, and that fact may be the reason why no oscular canals or distinct oscula are found. PORIFERA. I. 43 is of no frequent occurrence; the length occurring most frequently, is 0-298"""; the thickness varies from o-oi— 0-014""". Locality: Station 138, 63 26'Lat.N., 7 56' L98mm. 8. R. tubulosa Frstdt. PI. II, Fig, 5, PI. XI, Fig. 11 a, b, c, Fig. 12. 1887. Rnieera tubulosa Fristedt, Vega Exp. vetensk. Iakttag. IV, 419, PI. 24, fig. 1. The sponge is typically formed as rather thick incrustations, crusts, or cushions, provided with more or fewer, higher or lover, conical oscular tubes; but the form may be quite irregular. The dermal membrane is thin, without spicules, the ends of the fibres project, and therefore the surface is finely shaggy. Oscula are found on the summit of the oscular cones. The skeleton consists of a somewhat irregular uctzvork of polysplenia r fbres running towards the surface, and transverse spicules standing singly. Spicula are slender, somewhat curved oxea with a tapering 0/ varying length, and they may be rounded; the length is o'/y—o-20<> fathoms, we have a little specimen, which seems to have been lengthily pyriform; its length is 25'"'. The skeleton consist- oi unispi fibres. The spicules have a length of 0-20 o-23mm, and oftenest a thickness of o-oi Thus the sp with regard to the skeleton and the spicules, recalls A', parenchyma, the spicules, however, being on the whole a little smaller. With this species ma\ perhaps he classed some more or less cylindrical, parth hollow fragments I III In. Olf-l X,H In,,,,, VI I. 5° PORIFERA. I. from Talknafjord in Iceland, of a length of up to sp"™, and a thickness of ca. io,nm; their skeleton is likewise unispicular, and the spicules are of the same form, but a little shorter, not exceeding o-20mm, and most frequently a little shorter; they vary a little more in thickness, increasing to o-oi28mm; other- wise the\ are of the same form, and are also most frequently slightly curved in the middle. Reniera sp. b. PI. XII, fig. i. From station 3, 630 35' Lat. N., io° 24' Long. W., depth 272 fathoms, we have a very small fragment; it is, however, sufficient to show that it has belonged to a flat sponge; the skeleton is regular, formed by unispicular fibres, and the surface is finely shaggy. In the fragment are further seen a few polyspicular longitudinal fibres. According to this the sponge must have had a structure resembling that of the above described species parenchyma, folium, and ventilabrum. The spicules are characteristic by their size, being of a length of 0^3 — o-327mm, and a thickness of ca. 0-02 7mm; they are regularly and evenly tapering, and slightly curved or straight. Reniera sp. c. PI. XII, fig. 2. From Hekla Harbour we have some fragments brought home by the East Greenland expedition 1891 — 92; they have a unispicular skeleton, and may, as to their exterior, remind of R. clavata, but the spicules are quite different, being very slender and longer tapering; their length is 0-208 — o-238mm, but the thickness only o-oo8mm. This species might also, with regard to its form and skeletal structure, recall the R. simplex, established by Armauer Hansen in the Norwegian North-Atlantic Expedition, which cannot, however, be seen from the description; however, there is the difference that the spicules of the species of Armauer Hansen are somewhat thicker, o-oiomm, and their ends are more stubby. As I have had before me one of the original specimens of Armauer Hansen, I shall give a short description of the species. It will, however, have to get another name, as Bowerbauk in 1866 etablished a Reniera (Isodictya) simplex; I accordingly alter the name to Voeringii. 12. R. Voeringii Ldbk. PI. XII, Fig. 3. 1885. Reniera simplex Armauer Hansen (non Bow.), The Norwegian North-Atlantic Expedition XIII, 3, Tab. 6, Fig. 1. ' Lengthily fyriform, longstalked. The dermal membrane thin, without spicules ; the ends of the fibres projecting, unci the surface accordingly finely shaggy. The skeleton an irregular uc/iuork of primary and secondary fibres. The fibres unispicular. Particular polyspicular longitudinal fibres issuing from the stalk, are present. The spicules are slender, rather sharply curved oxea of a length of 0-22 — o-2j8mm. The sponge, as pictured 1. c, is lengthily pyriform with a rather long stalk; as the upper end has been broken off, it cannot be seen, however, how long the sponge has been, neither can the structure of the upper end be decided. Through the middle of the thick part a cylindric oscular canal runs, which has most likely ended in an osculum on the top. The length of the specimen is ca. 55mm, PORIFERA. I. of which the stalk is 30mm, the greatest breadth is 10""", and the diameter of the oscular canal is a few millimetres. The consistency is soft; the surface is finely shaggy from the projecting spicules, and the colour (in spirit) is light grayish yellow. The dermal membrane is thin, transparent, without spicules, and is pierced by the ends of the fibres. The skeleton is unispicular (not formed by bundles of needles, as stated by Armauer Hansen), and consists of primary fibres running regularly upward and arcuately outward towards the surf: and of spicules placed at right angles to these fibres, but forming themselves no distinct fibres; besides some thicker, polyspicular fibres run from the stalk up through the sponge. In the nodes the spi- cules are united by a clear mass of spongin. Spicula are slender oxea, rather sharply curved in the middle, of a length of o-22 — o^S"1"', and a thickness of 0-009 — o-Oiomm; they are of equal thickness through their whole length, and have a rather short, but very sharp point. This species, as will be seen, has spicules of a similar size as those in K. parenchyma; they may, however, easilv be distinguished from the spicules of this latter species, partly by their being more sharply curved, and especially by their ends, the point being bounded by curved lines, while in parenchyma it is longer and bounded by straight lines. The species is allied to clavala, but may be distinguished from this species by its thinner and more curved spicules. Locality: The species was taken by the Norwegian North-Atlantic Expedition on station 255, Vestfjord, 68 12' Lat. N., 15 40' Long. W., depth 341 fathoms; two specimens. Remarks: This species is the only Renzera-species taken by the Norwegian North-Atlantic Expedition, oblonga and vclamenlosa, as has been shown above, being ffalichondria-species, while tubit- losa, membranacea, nivea, and inflata belong in quite other places, and the rest are Axinellids. Note. Ya nh of feu, in the work quoted before, p. 24N, enumerates a Pachychalina oblonga Arm. Hans., which, to judge by a preparation sent to me, is no Pachychalina, nor Halichondria oblonga Arm. Hans., but a Re//iera-species\ it is impossible to determine the species after the preparation in hand, as the skeletal structure cannot be seen. To judge by the spicules tin- species might possibh be A', v.ntilabrum, but the outer form is by Vanhoffen stated to be quite different from that of this species. The AJr«/V/-<7-species described in the foregoing, divide into two groups: forms with unispiculai skeleton, and forms with polyspicular skeleton. All the forms with the regular unispiculai skeleton, as far as they are erect forms, have, besides this regular skeleton, a greater or smaller number of polyspicular fibres issuing from the base, where the) are thickest and closel) gathered, and from where they branch up through the sponge in a more or less regular manner, and without any decided relation to the other skeleton. This reminds of the fad described by Topsent by the establishing of the genus Cladocroce with the species fibrosa (Resultats des campagnes scieutifiques du Prince de Monaco, Ease. II, 72, PI. Ill, Fig. 1 2), and the other description of the structure of this species seems also to agree with the structure of the lamelliform specie- described in the present work. Topsen PORIFERA. I. iii the place quoted, also says that the genus is most closely allied to Reniera, but later he seems to have changed his opinion, in so far as he in 1894 (Une reforme dans la classific. des Halichondrina, Mem. de la Soc. Zool. de Fr. VII, 9) places it in the subfamily Gelliodince. I must suppose, however, that Cladocroce fibrosa is closely allied to the lamelliform Reniera-species treated of here, and I think it doubtful whether this genus can be kept apart from Reniera. Cladocroce fibrosa has spicules of a length of o-6mm, which is a considerably greater length than is reached by the spicules of the species described here, but in this respect it is well to notice that in the R. sp. b. mentioned before, the spi- cules reach a length of o-327mm. Metschnikowia Grimm. The form varying, as thinner or thicker crusts, or erect, more or It ss regularly cylindric or irregularly lobate. The skeleton forms a similar network as that in Reniera. The ends of the spicules are united by a most frequently very slight mass of spongin. Spicula are oxea or strongyla, evcryzvhere or for the greater fart set with small spines. 1. M. spinispiculum Cart. PI. XII, Fig. 4 a— b. 1876. fsodictya spinispiculum Carter, Descript. and Figures of Deep-Sea Sponges etc. on board «Porcupine», Ann. Mag. of Nat. Hist. Ser. IV, Vol. XVIII, 310, PI. XV, fig. 42. The form irregularly roundish or lobate, sometimes erect and irregularly cylindric. The surface with small, projecting -prominences, caused by the skeleton. The skeleton consists of a chiefly unispicular network of triangular or fefrahedral meshes. Spicula spined strongyla with curved ends, the length o-2o8—o-2ji'""". Of this species there are in the collection five specimens, none of which are attached, biit they appear all to have been broken off. With regard to the three specimens the form is erect and more or less irregularly cylindric; one shows a beginning division into two branches; the fourth specimen forms a little oblong cushion, and the fifth is irregularly lobate. The largest of the erect specimens has a height of 22mm, and the irregular lobate specimen has a greatest extent of 23'"™. The consistency is rather firm. The surface shows, especially under a magnifying glass, small prominences, but is not shaggy or provided with projecting spicules. The colour (in spirit) is whitish yellow. The dermal membrane is thin and transparent, and no particular dermal skeleton is found, but the membrane is resting on the skeleton below; the nodes of this skeleton projecting a little, small prominences are formed. The small, round subdermal cavities shine through the skin. The pores are round, and have been measured of sizes from O'ogS — o-ii9mm; the greater part is situated in the meshes made by the skeleton below. With regard to oscula, round openings, to be sure, are found here and there; but these open- ings, at all events the greater part of them, are scarcely anything else than subdermal cavities, over which the skin has been torn off; on the other hand, openings of a diameter of ca. imm are found in a few of the specimens, leading into a cavity which continues some way just below the skin and only covered by it; from this cavity canals go down into the sponge. PORIFERA. I. 53 The skeleton consists of a chiefly unispicular network the meshes of wliich are triangulai to put it more exactly, tetrahedral; therefore there is no question of primary or secondary fibres. The form of the ends of the spicules makes them to fit well into each other. In the nodes, in which, ac- cording to the construction of the skeleton of tetrahedral meshes, a greater number of spicules meet, these spicules are united by a very small amount of exceedingly clear spongin which is difficult to observe. Spicula are spined strongyla (acanthostrongyla) of a peculiar form; they are of equal thickness in their whole length, and have rounded ends; the ends are bent rather suddenly to a more 01 high degree; they may both be bent in one direction, or in opposite directions in the same plan, and they may finally be bent in different plans. Sometimes the bending is minimal. They are set with small, scattered spines, only the ends are smooth. The length varies between 0-208— o-238mm, which agrees with the measure given by Carter, I.e., viz. about 5°/6 inch =o-2iimm. The thickness varies between cvoio — croi2m"\ Finer spicules, developmental forms, occur in small numbers; these spicules are of interest as furnishing a distinct proof that the spicules are begun in full length; the fact is that the finest are of the same length as the fully developed ones, so that a growth only takes places as to thickness; the finest are of quite the same form as the fully developed ones, but are quite smooth, while the somewhat thicker ones begin to get quite minute spines; accordingly the spines appear first during the growth. To get a clear understanding of the growth of the spicules, it is of importance here to notice that the spicules of this species, which during the growth only increase in length to a very slight degree, are strongyla; a laying on of new parts parallel to the surface of the spicule will only lengthen such a spicule to an almost impercep- tible degree. The fact vill be quite different when the question is of long tapering spicules as oxea; in these spicules a laying on of parallel layers will lengthen the spicule considerably, so that a spicule growing to the double thickness, may also reach about the double length. The annexed sketch illustrates as an example the difference in the increasing of length in strongyla and oxea. Developmental forms of oxea, therefore, are always more or less shorter than the fully developed needles. When, what is often the case, the ends of the spicule during the development become more shortly tapering, than they are in the younger forms, the increasing of length is also comparatively smaller. Locality: We have five specimens of this characteristic species; east oi Iceland, 64 07' I. at. N., ii' 41' Long. W., depth 168 fathoms, two specimens (Wandel); Ingolf, the Denmark Strait, station 64 45' Lat. N., 27' 20' Long. W., depth 310 fathoms, three specimens. Geogr. distr. Of this species only one specimen had been taken before by the Porcupin* - expedition [870, station 25, 37 n' Lat. X., 9 07' Long. W., close to the north of cape St Vincent, depth 374 fathoms (Carter, I.e.). According to Topsent (Eponges nouvelles des Azores. Mem. de la Soc Zool. XI, 1898, 226), it was taken during the cruise of Princesse-Alii at the Azoi The genus Metschnikozvia now, after the addition of this interesting species, counts, as far as 1 am able to see, five species in all; of the other four species the three, tubcrculata Grimm, dia ,. PORIFERA. I. 54 Grimm, and flava Grimm, have only been found in the Caspian Sea (Dybowski: Studien iiber Spong. des russ. Reiches, Mem. de l'Acad. imp. des Sciences de St. Petersb. Ser. 7, Tom. 27, Nr. 6); the fourth, .]/. Filholi Topsent (Resultats des camp, scient. du Prince de Monaco, Fasc. II, 70, PI. IV, Fig. 7, PI. IX Fig. 6) is from the Azores. Petrosia Vosmaer. (Schmidtia Balsamo Crivelli.) The form varying. The consistency very hard, almost stony. Generally several, sometimes nu- merous, circular, sharply defined oscula. The skeleton consisting of a close reticulation oj 'thick fibres or more or less diffuse. Span gin (sometimes) present to a small degree. Spicula oxea or sf rangy la, most frequently short and thick. P. crassa Cart. PI. IV, Figs. 7—9. PI. XII, Fig. 5 a, b, c. 1876. Reuiera crassa Carter, Descript. and Figures of Deep-Sea Sponges etc. on board Porcupine , Ann. Mag. of Nat. Hist. Ser. IV, Vol. XVIII, 132. The form more or less irregularly roundish, tuberous or lobate. The skin with a dense reticulation of spiculo-fibres. Oscula scattered, circular with a sharp edge. The skeleton consists of a more or less regular network of polyspicular fibres, and besides some scattered spicules. Spougiu present to a small degree. Spicula oxea, dividing into two rattier well separated groups of size ; the length of the larger 0-2 — 7mnl, but the two groups, as has been mentioned, are not quite sharply separated. Besides these spicules not a small number of small, short and thick, curved oxea and strongyla may be found, and also other different forms (PI. VII, fig. 5 c). This species seems to be closely allied to P. dura Nardo, but it is distinguished from tl species by its longer spicules (the spicules of a specimen of /'. dura in the museum of Copenhagen measure o-26min); moreover, its fibres are not by far so thick 01 consist of so main spicules as I fibres of /'. dura. Locality: Station 1, 62 30' Lat. N., 8 21' Long. W., depth 132 fathoms, n> specimens. Geogr.distr. Carter. I.e., has the species from about the same locality, that is, a little south of the Faroe Islands, depth id; fathoms ( 1'orcupiiie 1. The occurrence of the species on this lath- is rather interesting, the genus not being hitherto known as northern, but only from the Medit ranean and more southern regions. 56 PORIFERA. I. Phlaeodictyon Carter. The form more or less roundish, sometimes lengthened or becoming quite irregular. Thr sponge provided with shorter or longer tubular processes, so-called fistula. The external layer marked oft' as a harder bark, highly provided with spicules. The oilier skeleton may be different, formed of fibres, or of a net of single spicules or oj irregularly situated spicules. Spicula are oxea, most frequently shortly pointed, sometimes strongyla : most frequently they are somewhat curved. Spongin (often) present, but not to any considerable degree. Carter, in 1882 (Ann. and Mag. of Nat. Hist. Ser. V, Vol. 10) established a new group Phlceo- dictyina, which he chiefly characterized by the outer form and the presence of processes (which might, however, also be wanting) as well as by a particular lamellar structure (structure essentially laminated and concentric ); he describes more particularly, how there are two different layers that may alternate with each other several times, but his description of this structure is not quite clear. To this group he refers Oceanapia robusta Bow., Rhizochalina oleracea and carotta Schmidt (1870, Spong. atlant. Gebiet., 35), Rhizochalina fistulosa Bow., and some new established species. The group thus established by Carter, has since been kept up as a subfamily to about the same extent given it by Carter, and with slight modifications in the definition. In the meantime a number of new species have been described under the genus Rhizochalina — Dendy comprises this genus and Oceanapia under the name Rhizochalina - - but many of these species agree only badly with the definition of the group given by Carter, having of the characters stated by him only the external hard layer, and being more or less provided with fistulae; among others this restriction holds good with regard to Rh.elongata Topsent, Rli. media Thiele, and several others. At the same time several authors have called attention to the relationship with Petrosia, for instance Ridley (Report on Zool. Coll. Alert 420), and Thiele plainly regards his Rh. media as an intermediate form between Rhizochalina and Petrosia (Stud, iiber pazif. Spong., Zoologica. X, 1897 — 99, Heft 24, 11,19, Tab. IV, Fig. 2, Tab. V, Fig. 11). It is also scarcely to be doubted that the genus Rhizochalina must be referred to the Renierincc nearest to Petrosia, where it has also to be referred according to its spiculatiou. Also in Petrosia a somewhat lamellar structure may be found, as mentioned before under P. crassa; but this structure is far from being found in all Rhizochaliua-species , and moreover it is probably a phenomenon connected with the growth of the sponge. As mentioned above, Rhizochalina oleracea and carotta Schmidt are found among the species, referred by Carter to Phhrodictyina. The original specimens of both these species are in the museum of Copenhagen, and by the examination of these specimens it has been seen that these two species have to be referred to the Chaliuiiue, as has also been done by Schmidt; the fact is that they have solid spongin-fibres filled with a large number of very small oxea. The concentric structure mentioned by Schmidt, and which has presumably been a chief reason why Carter has referred the species to J'hheodiclyina, is the same phenomenon, generally found in the Chaliuiiue, and which I take to indicate periods of growth. With regard to the other species, after the exclusion of oleracea and carol/a, for which species Schmidt established the genus Rhizochalina, another name must be chosen, and here Carter's name PhlcBodictyon ought to be used, which I have adopted accordingly. PORIKERA. I. The other genus of the supposed subfamily Phlceodiclyina is Occanapia. When Phlccodicty is dissolved, and Phlaodictyon is referred to the Rcnicrincc^ Occanapia will have to pass to Gelt where it belongs according to its spiculation, and then it must he nearly allied to Gclliodcs, from which it is only distinguished by its form and the external layer of hark. The genus must he taken to have its natural place lure, and in this respect it is rathei characteristic that Topsent has de- scribed loose fistulse of Occanapia just as belonging to the genus Gcllioda [G.cavicornis\ see otherwise for further particulars under Occanapia robusta). The result accordingly is that the hitherto admitted subfamily Phlcrodictyiuci ') is dissolved, the genus Phlcrodictyon (-- Rhizochalina olini after the exclusion of oleracca and carotta) is refei the Renieri)ia? close to Pctrosia, and the genus Occanapia to the Gclliincr close to Gclliod, It may easily be understood that the subfamily Phlcrodictyina' has been kept up lor some time, as the forms comprised in it show some congruity. The three P/ilccodiclyon-species enumerated here, the two GcHius-species, luridus and microtoxa to he described hereafter, and Occanapia robusta thus correspond in the presence of fistulse, and of an external, bark-like layer, and some of them have the mentioned lamellar skeletal structure. Moreover these forms show all the so-called Cellules spheru- le-uses , even if these cells are somewhat different. I think, however, that we cannot, at all events at the present position of systematism, ascribe any importance to these characters. Thus fistula- and a hard external layer of skin are also found in the genus Histodcrma. — L,indgren (Zool.Jahrb XI, i 297, Tab. 19, Fig. 11 a b| has also referred a Histodcrma-species to the genus Rhizochalina (the spi is wrongly determined as Rh. siugaporensis Cart.), and if the lamellar skeletal structure is a phenomenon of growth, no importance can be attached to it. Neither can any importance be attached to the occur- rence of Cellules spheruleuses , as long as their physiological significance is not sufficient!} known; besides I have found quite similar forms of these cells in a Histodcrma or a Desmacidonid-species closely allied to Histodcrma. Strange to say, these cells would thus seem to be especially developed and conspicuous in forms with an external bark-layer. - Altered points <,| view in systematism uia\ possibly alter the collocation of the forms here mentioned, but at present I think the dissolution Carter's Phlceodiclyina that I here have made, to be necessary. 1. Ph. tuber n. sp. PI. VI, Figs. 11 13, PI. XII, Fig.6a, b, Fig. 7. The form roundish, more or less irregular; only few fistula. Tin surface somewhat rough from projecting spicules, (hit, ■rums/ ,1 hard layer 0/ skin with irregularly placed spicules parallel to the sur- l,i c. Tin inner skeleton is ,m irregular fissut of spicules ivithout fibres, in this tissue are found . centric /avers of close-set spicules parallel to Hi, surface. Spongin present to a small a „ Spicuta curved oxca 0/ u length oj 0-28 o-j^""". This species may be of a somewhat varying form; but it is, however, in all the specimens in hand, more or less roundish or tuberous, and the sponge is provided with one 01 a lew fistulse. The largest specimen is lengthy; it has a greatest length of >8 '", and a greatest breadth of ca. 1,; 'i Carter for liis $;roup llse(' l,u uanu ol a ' yina. The [ngolf Expedition. \ I l 'am and -pecimen is scar- :>een broken of: . specimen has bad be jnc. - account of .id loose The rules bt ed off a^ which placed o": .'.: - tmbrar- ther small nrant the specimens. : Of se sponges aa e ends, i i ulatr accord:: be • eeD I ese ied i s - - ; - ■ S RUERA skeleton are united by a clear, not rvable n layer where the spicules are < may he observed, n the ules, bul □ other | here they touch each other, hut regard to the skeleton it has still I ticed that t' high degree inci bodies, large sp< ules being especialh frequently found. Spic/tla are somewhat curved oxea, the curve is mosl en and round, but also he more or less sharp, and sometimes it is somewhat irregular; the spicules are evenlv, hut mav best he termed shortly pointed. Their length is between < : "m, the thickiu rom 0"Oi2 — 0014 Shorter and finer, down to quite fine oxea, developmi in small numbers; the finest ones have a length of c. and thus they the fully developed ones; they an. ng tapering, ain' - [uently only during the growth. Lucidity: Station 7s. 60 37' Lat. X., 27 52' Long. W., depth 799 fathoms, one specimen 81, 01 44' Lat. X.. 2' 00' Long. W., depth ^5 fathoms, two small specimens station 90, ; 45' Lat N., 29 06' Long. \\\, depth 568 fathoms, two larger and two smaller speciim Th I] in the Denmark Strait, or somewhat south of it. 2. Ph. elongatum Tops. PI. VI, 1 .. PI. XII. Fig.8a,b,c, Fi 1S92. Rhizochalina >iou^.!t'i.|:"". The fine needles are long tapering, and consequently the short point appears only during the growth. Locality: Station 78, 60 37' hat. X., 27" 52' Long. W., depth 799 fathoms, one specimen; station 81, (|i l |' I. at. X., 27 00' Long. W., depth 485 fathoms, one specimen. Both stations are situated a little to the south of the Denmark Strait, station 81 on the Reykjanses-ridge, station 78 on the eastward slope of this ridge. Geogr. distr. The species has been established on four specimens taken on the expedition of the Prince of Monaco with rHirondelle in 1888 at the A/ores on a depth of about 138 fathoms (Topsent 1. a). PORIFERA. I Remarks. In these two species, but especially pronounced and in large numbers in the latter, some peculiar bodies are found; they are round, of a radiated structure, are refringent, and by a cer- tain adjustment they show a darker part or appear to be possessed of a cavity, which lad, however, I suppose to be due only to the refraction. The radiated structure ma\ he s<» pronounced as to continue into the periphery, so that they appear to be spined. They may reach a rather considerable size, and vary from 0-014— o'035",m. I take these bodies to he cells storing some substance or other, and to be- long to the category, called by Topsent cellules spheruleuses ; I think them so much the more to he such cells, as we find a large number of round cells, filled with refringent granules, which quite certainly correspond to the (cellules spheruleuses Tops., and between these latter and the former transitions are found in the form of cells filled with granules, beginning to show the radiated structure; the radiated form then is probably the full} developed phase of the cell. 3. Ph. irregulare n. sp. PI. VI, Figs. 9— 10. PI. XII, Fig.ioa,b. The form irregular, sometimes lengthened and somewhat cylindric, but twisted and nodm Only few fistula. The surface smooth. Outermost a thin, hard dermal layer loith very close-set spicules lying in an irregular way, but parallel to the surface. The interior skeleton formed of irregularly seat- tend spicules. Spongin present, but only to a small degree. Spun la curved oxea ivith a short, stubby apex. 0'1/tf — trJj'ioii Of this species we have lour very small specimens of a quite irregular form. The largest specimen has a greatest extent of ca. i^1""; it appears to have been attached with one surface; it has a quite irregular, twisted form, and shows marks of three broken off fistuke. The other specimens are lengthened, somewhat nodulous and bent, of a length of ca. ro ". and eacli has had two or three fistuke. The colour (in spirit) is yellowish white. The consistency is like that of the preceding species, internally the sponge is very cavernous. The surface is smooth, setting aside its nodules. Pores and •In: 1 have not observed pores in the dense-spiculed skin covering the body. As the fistulae have been broken off, nothing can he said as to their having been open or closed; only a single fistula appears to be whole, though not quite undamaged; it is quite short, and appears to have been closed at the end, and it shows in its outermost part a particular structure, the close-set spicules of the skin here bang more openly, and passing into a somewhat netlike arrangement, and here pores are found. The course of the canals I have not been able to examine, but I suppose these pores to he excurrent openings. The skeleton. Outermost is found a part formed a-- a dermal layer, in which the spicules are closely packed, considerably closer than in Ph. tuber. The spicules are lying in every direction, parallel to the surface. The dermal layer is thin containing not much more than one layer oi spicules, and the very highest thickness to which it reaches, is 0*03 \s far as I have been able to decide b\ the material in hand, the inner skeleton, as in the preceding species, consists of irregularly scattered spi- cules forming no fibres. As well in the skin as in the- inner skeleton the spicules arc united 1>\ a not copious and very clear mass of spongin; in the close-spiculed dermal layer the spongin is found in 62 PORIFERA. I. all points of contact. Also in this species some extraneous bodies are found incrusted, but to a far slighter degree than in the preceding species. Spicula are curved oxea, of equal thickness throughout their length; their point is short and stubby, sometimes with a little outermost apex especially marked off. The spicules are rather varying in length, from o-ijS— 0-24""", and also the thickness is somewhat varying, from ca. o-oo8 — o-oi2mm, the longest ones being far from always the thickest. Developmental forms, down to quite fine ones occur, but in small numbers; the finest have a length of ca. o'i66""'. The developmental forms are long tapering, but by and by, as the thickness increases, the points become shorter. Locality: Station 97, 65" 28' Lat. N., 2 70 39' Long. W, depth 450 fathoms, four specimens. Remarks. In this species cells filled with granules are found, but in smaller numbers and of considerably smaller size than in the preceding ones; forms with radiated structure were not found. Fam. II. Heterorrhaphidae. Subfam. 1. Gelliinse. Gellius Gray. The form exceedingly varying; it may be quite irregular, but it may also be definite and regular. for instance leaf-shaped, calicular, or pyriform. The skeleton is a more or less regular network or quite irregular, of reuieroid or Iialichondroid structure, and long fibres are not found. The mass of spongin is rather small, and does not quite surround the spicules or the fibres. Spicula: Megasclcra diactinal, oxea or strongyla : microsclera sigmata, sigmata and toxa. toxa. sigmata and raphid.es, or raphides alone. The genus is chiefly distinguished from Gelliodes by a more reticular skeleton without long fibres; the relation, therefore, between Gellius and Gelliodes is about like that between Biemma and Desmacella. 1. G. arcoferus Vosm. PI. XII, Fig. na,b, e. 1.XN5. Gellius arcoferus Vosmaer, The sponge of the Yillem Barents Exp. 1880—81. Bijdragen tot de Dierk., i2te Aflev. 3 Ged. 29, PI. IV, fig. 18, PI. V, figs. 87— 90. [887. . Fristedt, Vega Exp. vetensk. Iakttag. IV, 430, PL 24, fig. 29 — 31, PI. 28, fig. 16. i's9°- Lambe, Sponges from the Atlaut. Coast of Canada. Transact. Roy. Soc. of Canada, Ser. 2, II. Sect. IV, 184, PI. I, fig. 3, 3 a— b. Leaf-shaped? Spicula: Megasclera oxea 0-4-?"""; microsclera toxa o~ 057 — o-ij8mm, sigmata 0'Ol2 (i-i>i<)""". < >f this species we have only a little fragment; its form is compressed, and its one undamaged edge is rounded, so that it might be a piece of an erect, flat sponge; its colour (in spirit) is yellowish gray. Although \ osmaer gives no measures of the spicules in Gellius arcoferus, there can scarcely PORIFERA. I. °3 be any doubt that the present species is the same; it agrees also with the description by Fristedt and Lambe of the specimens, by those authors referred to G.arcoferus. Spicula in my specimen are of the following forms and dimensions: a. Megasclera are oxea, straight or slightly bent, and evenly and rather long pointed; their length is rather constant, and on an average 0*42 ', the thickness, on the contrary, is rather varying, 0-015— o-o22'"m '); shorter and finer oxea are found in small numbers, and are certainly developmental forms; b. Microsclera: n Toxa; these vary much in thickness, and also somewhat in length, but the thinner and shorter ones I suppose to be developmental forms; they seem to be begun in about their full length, and chiefly to grow only in thickness. They an- more or less curved in the middle, and just at the point the ends have a little bend the opposite way; in the finest of the bows the bend at the ends is often wanting. The length (which is somewhat dependent on the size of the curve) varies from 0-057- o-ijS"1"1, the thickness varies from 0-0014 — o-ooj"1"1; these are the limits between which the sizes of all the bows are found, but also the bows, the thickness of which in proportion to their length shows them to be quite developed, are somewhat varying, about from 0-119— 0-178""", and the thickness from 0-005 — 0-0(37""". 2' Sigmata; these are small, of a length from 0'0I2 — croic)""", the thickness is about 0'00imm. With regard to the skeletal structure it is to be noticed that the ends of the spicules are united by a distinctly observable mass of spongin. Locality: The only specimen, a little fragment, is from East-Greenland, ca. 72 40' hat. X., 20 00' Long. W., depth 100 fathoms. (The East-Greenland expedition 1891 — 92). Geogr. distr. Barents Sea, depths 140 and 170 fathoms (Vosmaer); to the north-east of the eastern Taimur peninsula, 76 52' Lat. N., 116 do' Long. E., depth 36 fathoms; Greenland 59' 33' Lat. N., 43 25' Long. W., depth 120 fathoms (Fristedt); the Gulf of St. Lawrence (Lambe). Accordingl) the species is widely spread in longitude, from 116- Long. H. to ca. 70 Long. W., but it has not been taken south of ca. 45 Lat. N. 2. G. angulatus Bow.? PI. XII, Fig. 12a, b, c,d. iS()(». Halichondria angulata Bowerbank, Mon. of Brit. Spong. II, 233, III, Tab. XLI, fig- | 8 1880. Desmacodes angulatus Vosmaer, Notes from Leyden Museum 11, 107. 1887. Gellim angulatus Ridley and Dendy, Challeng. Report. Monaxonida, Vol. XX, 2. 44. 1892. Topsent, Resultats des Campagn. scient du Prince de Monaco. Fasc. II, Of this species we have some roundish fragments, the largest of which has a greatest extent of 43""", but we have no whole specimen. I have not ventured to regard the determination as certain, especially as the species has never been satisfactorily described, and the spicules have not been figured since in Bowerbank, with the exception that Topseut (Contrib a Petude des Clionides. Arch, de Zool. experiment, el gen. Ser. 2, Tom. V, bis, PI. VI, Fig. 15) figures them, but with regard to the bows his figure does not agree well with that of Bowerbank, and the given measures do not agree with >) The spicules may also in different specimens Ik- of different thickness, .is already mentioned bj Vosni specimen before me from Greenland, sent from the Riksmuseuin in Stockholm, tin thickness 0 64 PORIFERA. I. those given by Ridley and Deiuh for the specimen of Bowerbank; Topsent also states that the •spicules project through the skin, while Bowerbank describes the surface as smooth. The species in hand has a thin dermal membrane that cannot, however, be torn off; no parti- cular dermal skeleton is found; but if a thin section is cut off parallel to the surface, this section shows an irregular network, which is polyspicular, but here and there also formed of single spicules. Spicules and bundles of spicules project through the skin, so that the surface is not smooth. The pores are round, and are situated in the meshes of the dermal membrane; they are measured of a size of o-oo8— o-i48""". The skeleton, as far as I have beeu able to examine it, has a somewhat halichondroid structure consisting of loose, little marked fibres, among- which, however, in many places, a unispicular reticu- lation is found. The ends of the spicules are united by a distinct, but clear mass of spongin. Spicula: a. Megasclera are oxea, more or less curved in the middle, gradually tapering to the point, which is most frequently somewhat marked off, and the very outermost point is ofteuest more or less shortly pointed; this structure, however, is not always pronounced.; the length varies between o-32 — o-388mm, and the thickness is 0-009— croi2mm. Shorter and finer oxea are only seen in very small numbers, b. Microsclera : 1) Toxa; with regard to form the)- resemble the bows of the preceding species, but they are smaller and especially thinner; the curve in the middle is sometimes so sharp, that the branches form a right angle; as in arcoferus the bending at the ends consists only of a little point inclined backwards. The length of the bows is between o-i2 — o-o64",m, and the thickness is from o-0O2mm down to o-ooim"\ 2) Sigmata; these are rather small, of an average length of o-02imm, and a thickness of o-ooi""". - - Besides these sigmata a very few much larger ones are found, of a length of about o-ojS" ■"■ and a thickness of o-oo5mn'. These sigmata are often of a somewhat monstrous form, with one or both ends rounded or showing other irregularities. As has been said, they are only found quite singly, but they are constantly found, so that they cannot be taken to be extraneous. They are not seen by transitions in sizes to be connected with the small sigmata. — In a specimen from Egedes- minde, the spicules of which were upon the wdiole of the largest of the sizes given above, the sig- mata were a little larger than those mentioned above, of a length of o-028ram and a thickness of o-oo2m"'. Locality: Adelvig on the north-western coast of Iceland, depth 6—15 fathoms, some fragments which have apparently belonged to one specimen (the author); Egedesminde, a few small fragments (Bergendahl). Geogr. distr. Gellius angulatus is common in the English Channel (Topsent), and has further been taken at the Azores (Challenger, Topsent) in the latter place on depths of up to 450 fathoms. 3. G. luridus n sp. PI. VI, Figs. 5— 8, PI. XIII, Fig. 1 a— c, Figs. 2— 8. hire; oblong pyrifomi, more or less irregular, sometimes roundish or lobate. The surface smooth. Outermost a bark consisting of a thinner or thicker layer with close-packed spicules lying in all directions, but parallel to the surface. The skeleton consists of a rather irregular, mostly ani- Spicular network; it is crossed by concentric lamella' of a similar structure as the dermal layer. Spi- PORIFERA. I. cnla: M vcu. 0-38— 0-47""" ; Microsclera toxa. rather small, greatest length i particular form with the shaft bent into an angle O'OiA — O'Oj""". This species is lengthily, but oftenest somewhat irregularly pyriform; the smaller specimens more roundish, a single one somewhat lobate. It must have been growing freely on the bottom, no place of attachment is found, but the sponge which is narrowing below, is here rounded, and ends often with a larger or smaller knob, especially marked off. The largest specimen has a height oi 60 and a diameter in the middle of 1 ;'"'"; then a series of specimens is found decreasing in size; the smallest specimen has a height of 9'""'. The colour (in spirit) in most specimens is dirtily yellow, but in a few it passes into a darker colour1). On account of the external rind-layer the consistency is rather firm. The surface is even and smooth, with here and there flat eminences and depressions. The spongi surrounded by a hard and firm dermal layer, provided with spicules lying in everv direction and ex- ceedingly close-packed, but all parallel to the surface; this part that is marked off as a separate layer, may be of a somewhat varying thickness, as will be more particularly mentioned below. Outermost thin dermal membrane is found, which, however, is not separable, and which I have only observed in a few places, so that it seems for the greater part to be destroyed. In this membrane the pores are found in the intervals left between the close-packed spicules; they are small, from o-oo;""" up t < > 0-029""", or, but rarely, somewhat larger. With regard to osai/a only one is found, in the upper end of the sponge; but I cannot give its structure and size, as the upper end is damaged in all the spi mens. The sponge is probably somewhat tapering above, or rather, as indicated by one <>f tin.- Vast damaged specimens shown in the figure PI. VI, fig. 5, it is here produced into a tube, in the end of which the osculum is then found; the presence of such a thin-walled tube would explain the fad that this fragile part has been broken off in all the specimens. Two oscular canals of equal width, running side by side, and only separated by a thin membrane, lead in all the specimens from the upp towards the lower end of the sponge (PI. VI, fig. 8); in the largest specimen they have a width above 0j |._^mm jni0 these oscular canals the excurrent canals open; they have a rather regular com running from the outside obliquely upward and inward towards the oscular canals and at the same time converging to wider canals. The skeleton. As mentioned the sponge is surrounded by a hard and firm part marked off as a dermal layer. The firmness of this layer is due to very closely packed spicules, lying in all direc- tions in several layers, but parallel to the surface. The thickness m. i\ be somewhat varying, but greatest in the lower part of the sponge, and decreases upward; in the lower part it may Ik- somewhat more than 1" . Where a knob-like lowermost part is especially marked off, this part consists almost o pletely of this skeletal tissue, which may here reach a thickness of up to 5 . When the derm, in the lower part of the sponge is rather thick, it consists also of heterogenous layers, layers with close-packed spicules parallel to the surface alternating witli layers, in which tin.- spicules are arran< in a more netlike manner, ami are not parallel to the surface. The other skeleton has a rather pecu liar, lamellar structure, consisting of thin lamellae, more or less parallel to tin ; these laun consist of close-packed spicules parallel to the surface, as in tin dermal layer; between the lamell 'i \ couple of the specimens are quite grayish black; this colour I take, howevei sponges, together \sith which thej havi been lying in spirit. The InKolf-Expedition. VI. i. 66 PORIFERA. I. mostly unispicular network is found. The lamellae orginate from the dermal layer and continue upward, bending into the sponge |P1. XIII, fig. 2), and they appear to form continuous layers all round the sponge. Thev consist of a dense feltwork of spicules lying in all directions parallel to the surface, but the spicules are not quite so close-packed as in the layer of spicules closest to the dermal membrane. The lamelhe are pierced by the canals, and therefore they show a great many round holes. As mentioned, a network is found between the lamellae. This network is rather irregular, its most regular feature is fibres running vertically on the lamellae towards the surface; these fibres are most frequently polyspicular; the other network is unispicular unci irregular. -- This particular lamellar structure, which is found as well in the thicker parts of the dermal layer of the sponge, as also especially marked off in the other skeleton, is not easily explained, but I suppose it to be connected with the way of growth of the sponge. The spicules of the skeleton are in the points of intersection united by a clear, but distinctly observable mass of spongin; the spougin is developed, not only at the ends of the spicules, but wher- ever the spicules are in contact with each other; therefore in the outer skin and in the lamelke, where spicules intercross in all directions, the spongin is present in all the points of contact, and imparts a great firmness to this skeleton. It is therefore frequently seen, when isolated spicules are examined that they are provided with coats of spongin in several places, where they have been in contact with other spicules (PL XIII, figs. 7, 8). Spicula: a. Microsclera are evenly curved oxea, only rarely they are a little more sharply bent in the middle; sometimes the curve is a little irregular; they are of greatest thickness in the middle, and taper somewhat towards the ends, the point itself, however, being only of a middle length; the length varies between 0387 — o-476,nm; the thickness varies between croio— o-oi28mm. Shorter and finer oxea are only found in small numbers, b. Megasclcra. 1. Toxa; these are rather small, obtuse-angled, and the ends are inclined backwards; they are of greatest thickness in the middle, and taper evenly towards the ends. The full-grown and largest forms reach a length of o-o6mm, and a thickness in the middle of ca. 0-002811"", but from this size downward all sizes and developmental forms are found down to so small a size as hardly to be observed; thus thev have been measured down to a length of o-oo5mm. According to this these bows appear during the growth not only to increase in thickness, but also to grow very much in length; the small forms, however, are always inscribable in the larger ones, when the angle is the same; and a growth by mere apposition of parallel layers will increase the length of the bows to a rather high degree; a growth in length by apposition, however, must certainly also take place, during which the inclined ends appear; these ends are not found in the smallest forms. 2. Sigmata. They are of a particular form, having in the middle a sharp, but obtuse-angled curve, and the first part from here outward is straight, but then the ends continue arcuately and taper to long points. Thus the middlemost part of this sigma reminds as to its form of a bow; the form may, however, be somewhat varying, and is sometimes rather irregular, which influences the length of the sigma, measured after the greater axis. The length varies from 0-014— ow,'"'", the thickness in the middle is ca. o-ooi""" in the larger, and a little less in the smaller ones. Remarks. In this species granulous cells — cellules spheruleusesi Topsent'l -- were found 1 These cells, no doubt, correspond to Tops cut's cellules spheruleuses ; but in naming them so, I do not mean ything as to their physiological signification. They are well known, and have often been mentioned, and different PORIEFERA. [. iii rather large numbers throughout the tissue; they are roundish, of a deep yellow colour (in spirit), filled with granules, and of an average size of o-oii"11". Embryos. In one of the specimens which was cut through, a cavity of a diameter of 5 was found in the lower third part of the sponge, in the tissue, between the oscular canal and the outer surface. In this cavity also the skeleton, even the skeletal lamellae were away, and its walls were lined by a thin membrane. In the cavity was found a number (ca. 20?) of roundish embryos of a diameter of about rmm. They were presumably each surrounded b\ a thin membrane, as fragments of such a one adhered to them when they were taken out. To judge by an examination of a cou] of the embryos, they seemed only to contain bows and sigmata, which were found copiously, and oi the same size as in the fullgrown sponge, but no megasclera. Locality: Station 78, 6o° 37' Lat. N., 27 52' Long. YV., depth 799 fathoms; station 90, 64 45' I. at. X., 29 06' Long. W., depth 568 fathoms, 9 specimens in all. The mentioned stations were both very rich in sponges, station 78 even the richest of all the stations. 4. G. microtoxa n. sp. PI. Xllf, Fig. 9a— d, Fig. 10. Oblong-pyriform. Outermost a rind-like, but comparatively thin dermal layer with rather c, pitched spicules lying in every direction, but parallel to flic surface': here and there this layer rises to small prominences, so that the surface is not smooth. The inner skeleton forms an irregular, polyspicular reticulation {probably with concentric lamella'). Spicitla: Megasclera oxea 0-62— o~ 68""" ; microselera toxa, very small, o~oi — cro2mm, sigmata of tin common form, but sometimes with the shall somewhat betit \o as to form an angle, crojj—O'oyS™'". < >f this species we have only a single, highl) damaged specimen, mostly consisting of tin outer layer of the sponge while the interior is wanting. To judge by this specimen the species has a similar form as that of the preceding one. The species has a length of 35""", and a greatest breadth in the middle of 15""". The colour (in spirit) is yellowish white. The surface is not quite smooth, as the spicules of the skin parallel to the surface, appear as a slightly conspicuous, irregular reticulation; besides the surface has rather close-set, low, knob-like prominences. As in the preceding species, the sponge is surrounded by a firm derma/ layer provided with spicules lying in all directions parallel to the surface, but they are not so close-set as in the preceding species; the dermal layer is also much thinner than that of the preceding species. In the membrane the pot scattered in the intervals between the spicules; they are measured of a size from 0-029 "ln ""• As the sponge is so much damaged, and the inner tissue is wanting, nothing can be said with regard to oscnla and canals. The skeleton. As stated above, the sponge has outermost a firm dermal layer provided with spicules lying irregularly in all directions, but parallel to the surface; these spicules, however, are not by far so close-packed as in the preceding species, and the dermal layer is much [thinner. In certain places some spicules rise pyramidically, their ends meeting, and consequently the skin is raised into authors ascribe to them different functions; evidently it is also these cells which Ridley and Dendy (Challeng. Report, Monaxonida, XX, p. XXII, pi. XLIX, figs. 1, \ a, 2 a) interpret as spongoblasts. PORIFERA. I. the low prominences mentioned above. As to the other skeletal structure, I have not been able to decide with certainty, whether concentric lamellae are found here as in G. lurtdus; but it would seem so, as a layer, constructed in the same way as the dermal layer, is found a little way within this latter. The other inner skeleton, as far as I have been able to decide, consists of an irregularly polyspicular reticulation. As in G. l/tn'dits, the spicules of the dermal layer and of the lamelke inside are, at the points of intersection, and not only at the ends, united by spongin; btit in the present species the spongin is only found to a very slight degree; the amount of spougiu is also very slight in the other parts of the skeleton. Spirilla: a. Megasclera are oxea, slightly, sometimes a little irregularly curved, and rather shortly pointed; the length is very constant, and is between 0-62 — o-68mm, the thickness is 0-014 — 0-017""", liner, to very fine oxea are found, but only in very small numbers, b. Microsclera: 1. Toxa; these are exceedingly small and fine; their form is obtuse-angled to rectangular, and they have, at all events the larger ones, a little recurved point; upon the whole they resemble the small toxa in the preceding species, being only more frequently rectangular or about so. Their length is o-oi — o-02mm, the thickness is less than O'ooi""". 2. Sigmata; while in the present species the toxa are smaller than in luridus, the siymata are larger; they have the common form, but sometimes they have a sharp curve in the middle, and so they resemble the sigmata of luridtis; upon the whole they are often somewhat irregular and angular in the curve. The length is somewhat varying, from 0-035 — o-078mm, and the thickness is in proportion 0-0018— 0-003""". In this species I have found developmental forms of sigmata; as was to be expected beforehand, the sigma is begun in about its full length, and it grows only in thickness and so far in length, as the recurved ends are formed and get their full length. The developmental forms I have found, which are only very few, are characterized as such by being fine, and not, or only to a small degree, having the ends bent in a hook-like manner; the length may be varying, and has, for instance, been measured to 0-05""". It is accordingly seen that the growth only takes place by apposition, and so it is proved that the small sigmata that are fully developed as to form, are not developmental forms of the larger ones, but are sizes that are present together with the larger ones. As well sigmata as toxa are present in large numbers throughout the sponge; besides sigmata are seen in rather large numbers in the skin, while toxa are not found there. Remarks: As in G.luridus 'Cellules spheruleuses Topsent are found in large numbers in the present species, but here they are only found in the dermal layer -- and in the layer inside the skin mentioned in the description — ; their occurrence in the dermal layer is rather peculiar; that is to say they are partly found scattered, but partly also closely gathered into bandshaped groups with a di- rection longitudinally of the sponge. These bands are distinctly visible to the naked eye or through a lens, and they convey an impression of being spiculo-fibres ; it is only under the microscope that they are seen to lie formed by the close-gathered cells (PL XIII, fig. 10). The average breadth of the bands s about 0"il — o-i5mm. The cells are roundish, elongated, or fusiform, sometimes produced at both ends to fine processes. Their colour (in spirit) is light yellow; averagely they are larger and with larger, more refringent granules than those of luridus. The roundish ones have an average size of 0-008— 0-017""", m«s reach a length of ca. o-035mm. Those scattered in the skin, are the greatest, and PORIFERA. I they are must frequently elongated; those gathered together into bands, arc smaller and nv quently round. Locality: Station 76, 60 50' LaL X., 26 501 Long. W., depth 806 fathoms; only one damaged specimen. Xote. The two species now described, G. luridtis and /uicrotoxa, as well by their spiculation as the whole other strnctnre, thus, I suppose, also b\ their numerous and distinct cellules spheru- leuses , appear to be very nearly related; but on the other hand characteristic differences are found, both in spiculation and other structure; thus with regard to the spiculation, the sizes of the spicules and the reciprocal proportion of their sizes, as also the different structure of sigmata. In the skeletal structure is especially to be noted the difference that the spiculation of the dermal layer — and of the layer inside constructed in a similar manner --is far more deirse in one than in the other, and also the amount of spongin is different. Finally is to be noted the difference with regard to cellules sphe- ruleuses and their occurrence. On account of the rind-like dermal layer and the lamellar structure of the skeleton, as als< account of both species presumably having been provided with a fistula , these two species might be referred to the genus Occanapia, but then this genus would have to be extended so as also comprise species with toxa; if with Dendy we should prefer to unite it with Rhizochalina [I'hLr, tyon mihi), it would accordingly contain species without microsclera, species with sigmata, and species with both sigmata and toxa. In the present work, however, I have only kept the genus Occanapia for the species robusta (for particulars see under this species and the introduction to the genus /'/,. dictyon). 5. G. primitivus n. sp. PI. XIII, Fig. n a— b. Crust-shaped, ////////it or thicker. The skeleton is a rather regular uctzv rt it is unspicular, but polyspicular fibres are found , especially running towards tin s Spicula : .!/ sclera curved oxea o'ljy — o'i66mm; microsclera tine toxa o~o28- o-ioy""". We have oulv this species in more or less damaged specimens, and in dry state, so that the description must chiefly be restricted to the spicules. The species grows incrusting on a branched Lithothamnion, one of the specimens shows a tube. The greatest extension reached b\ any of the specimens, is ca. 14""". The colour in the dried state is yellow. As far as I have been able t«> judge from the specimens in hand, the surface is shaggy, the dermal membrane being pi \ the ends oi tile spicules. The skeleton consists of a rather regular network, partly unispicular, but also polyspicular fi- bres are found in it, especially running in the direction towards the surface. The skeletal meshes more or less rectangular. Especially the fibres running towards the surface (the priman distinct, while the fibres running vertical^ on these are less conspicuous, [n the nodes of the si the spicules are united by a distinct and rathei copious mass of spongin. Spicula .-a. Megasclr.ru are oxea; tin 0 ss, most frequently rathei strongly, and _, , PORIFERA. I. sometimes irregularly curved; they are of about equal thickness in their whole length; the points are somewhat varying- in length, but are always rather short. The length of the oxea is between 0-137— o-i66""", and may in a few cases reach o-i78mm. The thickness is rather varying, and the longest ones are not the thickest; it varies between 0-003 — o-oo7mtn, the thicker ones being most frequently met with. b. Microsclera; only one form of microsclera is found, viz. toxa; they are all fine, but very much varying in length, and also their form is somewhat varying, and rather frequently somewhat irregular; their curve varies very much, so that they may be from almost straight to rectangular; in many of them the ends are a little inclined backwards, while in others this inclining is wanting. They are of equal thickness in their whole length, and upon the whole their appearance is very simple. Their length is from ca. 0-028 up to o-i07mm. The thickness is ca. o-ooimin or somewhat more in proportion to the size1)- I '.•■cnlitx : Juliauehaab (inspector Ryberg). We have in all seven specimens or fragments, all growing on a branched Lithothamniou. 6. G. proximus n. sp. PI. XIII, Fig. 12 a— b. Crust-shaped, incrusting. The dermal membrane thin, the nodes of the skeleton below make it htly granulans, and it is slightly shaggy from projecting spicules. The skeleton (or by far the greatest part of it) is unispicular, and forms triangular or irregular meshes. Spicula: Megasclera oxea 0-149 — 0'i84mm; microsclera line toxa 0-028 — y""". Of this species we have only two small specimens growing as incrustations on Balanoid shells; the greatest extension is i7,nm, but the specimens are scarcely quite whole; the thickness is ca. 4mm. The surface is slightly granulous, and spicules project. The colour (in spirit) is a light gray. The dermal membrane is thin and transparent, and the spicules below it form a reticulation of mostly tri- angular meshes; the nodes rise a little which is the cause of the granulous appearance of the surface; besides spicules from the skeleton project through the skin, and so it is slightly shaggy. Pores are found in large numbers in the meshes, and are measured of a size from 0-017 — 0'i8mm. The skeleton is unispicular, and consists of triangular or irregular meshes, polyspicular fibres are perhaps also found. The part of the skeleton immediately below the skin forms rather regular, triangular meshes that may be seen through the skin as a reticulation. The ends of the spicules are united by a clear, copious mass of spongin. • Spicula: a. Megasclera are oxea; they are slightly curved, sometimes almost straight, of equai thickness in their whole length, and more or less shortly pointed; the points are often rounded, and then sometimes provided with a little mucro. The length is between 0-149 — o-i84",m; thev are rather thick, the thickness varying from ca. 0-006 — o-oi'nm. Finer needles, developmental forms, occur in small numbers, b. Microsclera: only one form of microsclera is found, viz. toxa; they are of quite the same form as the bows in the preceding species, and they are also very fine, and van7 in size and form; I As the bows vary very much with regard to the degree of their curving, and as also the megasclera are sometimes ther strongly curved, spicules may be found, with regard to which it cannot be decided, whether they are bows or deve- lopmental forms of oxea. PORIFERA. I. the length is the same as m the preceding species, and is between 0028- 0-iO7mm. In the- largest ones the thickness reaches to 0-002"""; hut in the smaller it is somewhat less. Locality: Egedesnrinde (Bergendal), depth 15 fathoms, one specimen; the mouth of the Ameralik fjord (Ingolf) one specimen; both specimens grow on Balanoid shells. Although I have only had so slight a material of these two species I have thought it best to describe them, as their spiculation is interesting, and separates them very well from the other Gellius- species. Of the hitherto known Gellius-s-pecies provided with toxa, G.angulatm Mow., arcoferusM osm., and fiabclliformis Ridley and Dendy, have also sigmata; only G. pumiceus Frstdt (Kgl. Sv. Vetensk. Akad. Haudl. Bd. 21, 110.6, p. 29, T. II, fig. 9 a— d), and G.toxius Tops. (Rev. Suisse de Zool. IV, r have a spiculation consisting of oxea and toxa without sigmata; but in pumiceus oxea have a length of 0.9""", and toxa have another form; neither seems G.toxius, of whose spicules we, unfortunately, have no figures, to agree with any of the species described here. Note. According to what is stated above, the genus Gellius may have the following combi- nations of spicules: o\ea and sigmata (the most common easel; oxea, sigmata and toxa; oxea, sigmata and rhaphides, in bundles or scattered (massa Cart., macrosigma Tops., G. sp. (pyriformis) Ridley and Dendy, Challeng. Report, Monaxonida, 46, and phillipensis Dendy, Proc. Roy. Soc. Victoria VII, C895, 2 oxea and rhaphides (Lacazci Tops., Arch, de Zool. exp. et gen. Sen I, I, 1893), aU(' finally oxea and toxa. I think it doubtful whether the genus Rhaphisia Tops, the spiculation of which consists of oxea and rhaphides or trichodragmata (anonyma Cart., laxa Tops.), or of oxea, trichodragmata and toxa (sp Tops.), can be kept up, as the character given by Topsent, of the skeleton forming no regular net- work, is scarcely sufficient to make good the establishing of the genus; and it must therefore, I think, be referred to Grllius. The bows figured by Topsent for Rhaphisia spissa (Mem.de la Soc. Zool. d< XI, 1898, 232, fig. 2 c) remind of the bows in the two species described above, but they are larger. 7. G. flagellifer Ridley and Dendy. PI. II, Fig. 9, PI. XIV, Fig. 1 a— d. [886. Gellius flagellifer Ridley and Dendy, Ann. Mag. Nat. Hist. Ser. 5, XVIII, 333. 1887. Ridley and Dendy, Challeng. Report, Monaxonida, XX, 42, PI. XIII, figs. 5 and co. Oblong-cushionshaped. The surface somewhat shaggy. Thi dermal membrane thin, res the subjaci i/f reticulation oj polyspicular fibres. The skeleton consists <>/ an spicular ///ires. Spicula : Megasclera oxea 0-417- "'447" '"' ■' "ll< flagellate sigmata o-oyS—o-og""". Of this species we have one specimen agreeing both in outei form, structure and spiculation \ well with the quoted descriptions. The form of the specimen is as an oblong cushion, and it app< to have been attached. It has a length of 34"™, a breadth oi :o" . and a thickness ,.1 colour (in spirit) is yellowish white. The surface is somewhat shaggj from projecting spicules. The dermal membrane is thin and transparent, and rests on the subjacent skeleton which forms, below the skin, a coarse reticulation of polyspicular fibres. From the nodes spicules or bundles oi spicules arise, -, PORIFERA. I. and give to the surface its shaggy appearance1). In the meshes of the reticulation numerous round or most frequently oval fores are found, measured to a size of 0-017 — o-iio,",m. In the dermal mem- brane sigmata of the common form are copiously found. The skeleton^ as stated by Ridley and Bendy, consists of an irregular reticulation of poly- spicular fibres; especially the fibres running towards the surface (the primary ones) are distinct, while the others are indistinct, lying irregularly, or dissolved into single spicttles. The primary fibres have an average reciprocal distance of the length of one spicule. The number of spicules in the primary fibres may be somewhat varying, but most frequently it appears to be 4 — 6. As mentioned, a coarse and irregular reticulation is seen under the skin, and this reticulation is accordingly formed by secoud- arv fibres, but in the nodes the ends of the primary fibres project making the surface slightly shaggy. Spongiu uniting the spicules is found, but to a rather slight degree; besides it is clear, and therefore not easily observable. Spiculu : a. Megasclera are oxea, slightly and evenly curved, more rarely with a somewhat sharper curve, with evenly, but not long tapering ends. The length is rather constant 0-416 — o'447mm; only rarely it goes down to o^S111"1, or rises to o'476mm; also the thickness is rather constant, and is between o-oi6 and o-oi2mm. Shorter and finer spicules are found in very small numbers, b. Micro- sclera : 1. Sigmata of the common form ; these sigmata have a regular form, the}- are rather varying in length, from 0-02 — o-0/mm; the latter size, however, is only rarely attained, the average size being about o-o4mm; they are rather fine and have an average thickness in the middle of ca. o-ooi8mm; the greatest ones may reach a thickness of up to o-oo26mm. These sigmata are frequent throughout the sponge, and occur in especially large numbers in the dermal membrane. 2. Flagellate sigmata; these sigmata are long ones, so highly curved in the middle as to get two more or less parallel arms; the ends are evenly pointed, and are bent inward in an almost rectangular or acute-angled way and with a rather sharp curve; most frequently, but not in all instances, one arm is somewhat longer than the other, and the short arm has the largest hook. With regard to the size, the greater axis of the sigma is 0-078 — o-oo,m"\ and the smaller axis about o-057mm. The thickness is between 0-0028 — o-oo35mm. These sigmata are rather numerous through the whole sponge, although not so numerous as the small ones, and they are not found in the dermal membrane. The flagellate sigma of my specimen shows a little difference from the figure in Ridley and Dendy; this difference, however, consists only in the fact that the hook of the short arm has not in the figure of Ridley and Dendy the sharp curve described by me; there is, however, no reason to put any stress upon this fact, as these sigmata upon the whole are somewhat varying in form, and Ridley and Dendy have only figured a single individual. The measures of these authors agree with my measures, when we notice the fact that they give the length from the shortest arm to the curve; a remeasuring of their figure gives the length of o-o8m,n for the greater axis. 1 M the small sigmata the said authors say: possibly young forms of the others ; this opinion is a consequence of the way in which they explain the growth of the cheke, since they, with regard to these spicules, also interpret the small forms as developmental phases of the larger ones. In order Ridley and Dendy say: Surface .... slightly rough, probably owing to the dermal membrane having been in 1) off». The surface, however, as will appear from the description above, is also shaggy when undamaged. PORIFERA. I. 73 to make this fact possible, a growth would have to take place involving a complete transformation of the form of the spicule, because the small sigmata are not inscribable in the flagellate ones; now it has later been proved by Levin sen (Vidensk. Meddel. fra Nat Foren. i Kobenhavn for 1893, 1) that tin- growth of the chela; exclusively takes place by apposition; of course the same fact must be supposed to be the case with regard to the sigmata, so that the small sigmata and the flagellate ones arc- different bodies without any connection with each other. Neither is any transition found between these I forms, as also flagellate sigmata are found in the following species without being accompanied by common sigmata')- I must add, however, that I have found no developmental forms of the flagell; sigmata. Vosmaer (The sponges of the Villem Barents Exp. 1880 — 81, Bijdragen tot de Dierkunde, 12. Aflevering, 3. Ged. 29, PI. IV, figs. 35, 37, 38) mentions as Gellius vagabundus var. ;- a species with both flagellate sigmata and sigmata of the common form. To judge from the figures of as well oxea as sigmata, and as the species has both kinds of sigmata, it is rather probable that the specie- is G.flagellifcr, but as Vosmaer gives no measures it cannot be decided with certainty. Locality: Station 52, 63 57' Lat. N., 130 32' Long. W., depth 420 fathoms. Only one specimen. Gcogr. distr. Off Marion Island in the South Sea, depth 50 75 fathoms (Challenger). The form mentioned by Vosmaer is from the Barents Sea. Accordingly the species appears to be very wi- dely spread. 8. G. porosus Frstdt. PL XIV, Fig. 2 a— c. 1887. Desmacella porosa Fristedt, Vega Exp. vetensk. Iakttag. IV, 440, PI. 24, figs. 36— 37, PI. 28, fig. 15. 1896. Gellius flagcllifcr Lambe, Sponges from the Atl. Coast of Canada, Transact, of the Roy. Soc. ol Canada, Sen 2, II, Sect. IV, 185, PI. I, fig. 4 — 4 d. 1896. ? Gellius flagellifer Topsent, Campagne de Caudan dans le Golfe de Gascogne, Annales de l'Univ. de Lyon, XXVI, 280, PL VIII, fig. \. Tuberous, or rounded, more or less irregular. The surfact shaggy; the dermal membrane thin. The skeleton a somewhat irregular network with triangular or quadratic meshes. Sptcula: Megasclera oxea o'2j — o-j2mm; microsclcra (common sigmata fj, flagellate sigmata o'oy—o'imm. Of this species we have one specimen, of an irregular, roundish form; it is, however, somewhat damaged, and perhaps it is only a fragment; by far the greatest part of the skin is wanting. The greatest extent of the specimen is ca. 30""". The colour (in spirit) is gray; wit! rd to consistent the specimen is very brittle; it is perforated by numerous larger and smaller canals. The spong( throughout highly interwoven with sand and extraneous silicious bodies. The surface, as far as I have been able to decide, seems to be slightly shaggy from projecting spicules. The skeleton consists of a rather irregular, unispicular network of triangular and quadratic '1 In sigmata of the common form the fact is also that the smaller ones cannot be, while the finei developmental phases, as most of the smaller have their final form, and an apposition would only make them thicker; apposition worth mentioning took place in the longitudinal direction, de onus would appeal For further particul of the growth of sigmata see under G.microtoxa, p. 6S. The I" ;oll 1 *pi dition. VI. i. PORIFERA. I. meshes; here and there polyspicular fibres are found that seem especially to run towards the surface. In the nodes the spicules are united by an only little conspicuous mass of spongin. Spicula: a. Megasclera are oxea, evenly or a little more sharply curved, and evenly tapering; sometimes they are rather long tapering. The length is somewhat varying, in the specimen in hand from C25 — o-32mm; the thickness is ca. croi — con"1"1, b. Microsclera ; these are flagellate sigmata of a similar form as those of the preceding species, but somewhat varying in form (PI. XIV, fig. 2 b); in the most typical form one arm is curved, and much shorter than the other; the greater axis measures 0-07 — o-imm, and the smaller axis ca. 0-05 — o-c>57mm; the thickness is about o-oo28mm. Besides the flagel- late sigmata, other sigmata are also found singly, of about the common form, but with the ends highly recurved; they are rather large, the length being 0-05— cvo8mm; as they only occur in very small num- bers, and as the flagellate sigmata are much varying in form, they might be taken to be only a va- riety of the latter; against this supposition, however, their thickness appears to tell, it being somewhat greater than in the typical flagellate sigmata, viz. ca. o-oc>4mm (PI. XIY, fig. 2 c); this fact, however, does not exclude the possibility of their being varieties, perhaps monstrous varieties, of the flagellate sigma, of which irregular, monstrous forms are not rarely found, reaching a colossal thickness, viz. o-oo7mm. This species is distinguished from the preceding one, besides by differences in the length of oxea, chiefly by its unispicular skeleton, and by the want (or the scarcity and form) of common sigmata. As I have had before me a piece of the original specimen of Fristedt, I have been able with certainty to decide the species, which otherwise agrees very well with his description; Fristedt gives the length of oxea to be constantly o-35mm; my measurings of his original specimen, however, give the same measures as stated above for my specimen. Neither does Fristedt mention sigmata of the common form, which he is likely to have overlooked on account of their scarcity, but they are to be found in his specimen. I think the referring to the present species of the G. flagellifer mentioned by Lam be 1. c. to be rather certain; he also mentions that common sigmata are found in small numbers. On the other hand it is more doubtful, whether the G.flagellifer mentioned by Topsent 1. c, is the present species. Topsent says that the spicules are the same as those in G. flagellifer R. and D., but besides oxea he only mentions and figures flagellate sigmata, and as the measures agree rather well with those of the present species, and the skeleton is described in the term ligues unispieulees , I must suppose it to be identical with the present species; at all events it seems impossible that it can be G.flagellifer R. and D. Locality: Skagestrand Bay on the northern coast of Iceland, depth 119 fathoms, one specimen; 63 15'LatN., 90 35' Long. W., a little fragment (Wandel). Geogr. distr. The Davis Strait, depth 70 fathoms (Fristedt); the Gulf of St. Lawrence, depths 37—80 fathoms (Lambe); ?Gascony Bay, depth ca. 200 fathoms ( Caudau ). Note. Thus it appears that at all events two distinct species with flagellate sigmata are found; these species have been intermingled, the existeuce of a flagellate sigma obviously having been irded as a proof of the identity of the species. The first author, who mentions and figures such a sigma, is O. Schmidt (Spongienfauna des atlant. Gebiet. 1870, 53, Tab. V, Fig. 15). He mentions it porifera. i. pl- under his Desmacella vagabunda, which has been the cause that Vosmaer has referred the species before him to Gellius vagabundus as a variety. The species of Schmidt is from Florida from a depth of 228 fathoms, but as no nearer description or measures are given it cannot be decided, whether the species is either of the species mentioned here, or perhaps a third species. The flagellate sigma is oi a peculiar form, but we cannot lay much stress upon that, especially as we do not know, whether the figured form is the typical one. Gelliodes Ridley. The form somewhat varying, sometimes irregular, but often well defined, erectly cylindric, . or funnel-shaped. The skeleton Inn always well developed, often long fhr, v. with more or less, but most frequently rather little spongin. The fibres may form a network, or be arranged in a more dendritic manner. Spicula: Megasclera diac final, oxea; microsclera sigmata or sigmata and to 1. G. plexa n. sp. PI. V, Figs. 3— 4, PI. XIV, Fig. 3 a — d, Figs. 4— 5. Erect, funnel-shaped (probably always so). The dermal membrane thin, resting- on the subjacent, irregular network; spicules and bundles of f /cities prof -el. and there/ore ". , surface is finely sp Oscula only found on the inside, numerous and small. The skeleton consists of numerous powerful, poly- splenia/- fibres branching from the base, which is almost exclusively formed by these fibres, up through the sponge, and forming a very solid skeleton. Rather little spongin. Spicula: Megasclera ■ 1 -41- — °'5J''""- microsclera toxa <<•// — omi6"""; sigmata 0-0128 — o'oi$mm. The specimens in hand of this species have been somewhat damaged in the trawl, so that there may be some doubt as to the outer form of the species, at all events with regard to the limits between which it may vary. We have two pieces of a form as erect leaves narrowing below, but here they are broken off. In both pieces one surface is a little convex, the other a little concave. On the other hand a third, somewhat smaller specimen has a calicular form, and narrows also below; bul also this specimen is broken off here. According to these facts it is probable that the two Erst-mentioned pieces are parts of a likewise calicular sponge, and that the form of the species is as a perhaps short- stalked cup with a wide opening. Of the two mentioned pieces one has a greatest height of 1 30""' and a breadth of ca. 90"""; the thickness in the middle is 10 — 12"11"; it is greatest below, and decu wards the upper edge; thus where the sponge is broken off, it is ca. 22"1"1. The calicular specimen which is also much damaged, is somewhat smaller, it has a height of 7511""; the width of the tunnel cannot be given with certainty, as the edge is broken off, but may be estimated at ca. 45™", and the thickness below where the specimen is broken off, is about iN""". The 1 | is grayish white or somewhat darker grayish. < >n account of the mam strong longitudinal fibres the consist, is rather firm. The surface where it is undamaged, is finely spiuulous on account of tlu ting spicules and bundles of spicules. The dermal membrane is thin, and rests 011 the subjacent irregular network of fibres. Oscula and pores: As the skin is only k< small extent, the facts with regard PORIFERA. I. to the situation of oscula and pores have only been discernible in a few places; especially the skin of the outer surface has only been kept in a few spots. As far as I have been able to examine the facts they are as follows: On the inside of the cup distinct, sharply defined circular oscula may be seen with the naked eye in abundant numbers. They are of a somewhat different size, of a diameter from ca. i — 2""". When a piece of the skin is examined under the microscope many smaller openings arc seen decreasing in size quite down to o-i2mm. On the outer side no greater openings visible to the naked eye, are seen, but under a lens or a microscope numerous openings are found, of sizes mea- sured from 0-029— o'3mm. The small openings of a size of about o-02o.mm are the most numerous, and are generally gathered into groups. While thus the openings of the inside upon the whole are greater than those of the outside, they are, as is seen from the above, not sharply separated with regard to size, the greatest openings on the outside being greater than the smaller ones on the inside. The openings of the outside, I suppose, act as pores and those of the inside as oscula. Numerous canals oi an average diameter of 2 — 3mm go more or less horizontally through the wall of the sponge; they have the greatest width towards the outside. They are distinctly seen, when the skin and the skeletal tissue supporting it is removed. The oscula of the inside, at all events the larger ones, are direct openings of these canals. The skeleton consists of powerful polyspicular fibres branching up through the sponge from the base where they are so closely pressed together as to form a compact mass. They are thickest below, and may here be coalesced into bundles of a thickness of a few millimetres; upward they be- come thinner. They branch in a dendritic way up through the sponge frequently anastomosing and coalescing with each other. As the fibres are numerous and placed close together the whole thing forms a very strong skeleton crossed by the horizontal canals mentioned above, which run in the in- tervals between the fibres; the sponge is otherwise so closely interwoven with these fibres that the soft parts are only little conspicuous. The finest fibres form a close, irregular network filling out the intervals between the principal fibres. On either side of the sponge an irregular network is also found on which the skin is resting; from the nodes of this network the bundles of spicules arise that make the surface finely spinulous. The fibres are firm and solid; their spicules are united by a clear mass of spongin which is not, however, so copious that it may be distinctly seen to coat the whole fibre, even if it is perhaps completely or for the greater part lined with a thin layer. Spicula: a. Megasclera are oxea, very evenly tapering, and evenly and slightly curved, some- times straight, more rarely they are somewhat sharper curved; the length is between 0-417 — 0-53""", most frequently it is 0-44 — o'47mm. The thickness is ca. 0-018 — o-o24mm, the thickest ones being gene- rally not the longest. In a specimen (from East-Greenland) the most frequent length of the needles is 0-41 7!nm, and may be even less, and they do not reach o'47mm. Shorter and finer needles are found, but only in very small numbers, b. Microsclera: 1. Toxa; these are rather large, regularly formed bows forming an obtuse angle; only rarely it is somewhat sharper. The ends form short, recurved points. They are thickest in the middle, and decrease, but only slightly, in thickness outward. Their length is between o-n and o-i6mm, and the thickness in the middle is between o-oo4^-o-oo7mm. Besides these fully developed bows, some finer, to exceedingly fine ones, are found; these latter are on an rage not much shorter than the thicker ones, only the very finest go down to a length of o-057mm. PORIFERA. I. These fine bows I suppose to be developmental forms; to be sure, they are possessed of the recui points, but there seems to be no objection to the supposition that by a growth by mere apposition they may attain the same form and size as the large ones. 2. Sigmata; these are small and rather constant size; the length is 0-0128 — o-oi5mm, and may in a few eases reach croi8mm; the thickness is about crooin"n. Toxa and sigmata occur throughout the sponge, but are especially abundant in the dermis. Locality: Station 2, 630 04' Lat. N., 9 22' Long. W., depth 262 fathoms, a calicular specimen; station 3, 630 35' Lat. N., io° 24' Long. W., depth 272 fathoms, two leaf-shaped fragments; 63 15' Lat N., 90 35' Long. W., depth 270 fathoms, a little fragment (Wandel); 72 40' Lat. X., ca. 20 Long. W., depth 100 fathoms, a little fragment (the East-Greenland Expedition 1891 — 92). Accordingly the has been taken to the northwest of the Faroe Islands and off the northern East-Greenland. 2. G. consimilis n. sp. PL XIV, Fig.6a-e. (Leaf- or funnel-shaped?). The skeleton consisting 0/ numerous solid polyspu ranching through the sponge and forming a 'solid skeleton. Rather small amount of spongin. Spicula: Mcgasclcra oxea 0-528 — o-66""" : microsclera toxa omnp — o-/g""". sigmata 0-018 0-0261 Of this species we have only a small fragment of a greatest extent of ca. 20 ; the fragment is flat, of a thickness of 5 — 6rara, and it must have belonged to an erect, flat, i. e. leaf-shaped or cali- cular sponge. The structure of the fragment, otherwise, is like that of the preceding species; the same solid, branched fibres are found, arranged in the same way, and the sponge is also pierced by hori- zontal canals of a similar size. The skin is wanting, so that nothing can be said with regard to oscula and pores; on one side, however, one single, naturally bounded osculum is seen, of a diameter some- thing more than imm. The skeleton, as has been mentioned, is of quite the same structure as in the preceding sp< and consists of solid, branching, and anastomosing fibres, the intervals between which are filled by an irregular polyspicular network. The spicules of the fibres are cemented by a clear mass of spongin which is not seen here neither to form a distinct layer round the spicules. Spic nla: The combination of the spicules is the same as in the preceding species, but the di- stinguishing character is to be found in the form and sizes of the spicules. .1. Mcgasclcra are oxea; these are slender, and evenly and Ion- tapering; they are slightly curved, but rather frequently the curving is rather sharp, and then they may in form remind somewhat of the spicules of Hahchondria panicea. The length is between 0-528— o-66mm, and the thickness 1 . A few shorter and finer needles are seen. b. Microsclera: 1. Toxa; these are of the same form as in the preceding species; the length varies from ca.0-1.19 M191""1, the thickness from ca. line bows, deve- lopmental forms, are also seen, but only in quite small numbers. 2. Si. hese are of a lengtl 0-018— o-0268mm, the thickness is ca. 0-00imm. Both with regard to structure and spiculation this sp be very cl ated to the preceding one; but it is very well distinguished from this latter species by the size oi the spi- 7« PORIFERA. I. cules and especially by the form of the oxea, which is quite different from that in G. plcxa; for the fact that the sizes of all three forms of spicules are above those in G. plexa, can scarcely by itself be regarded as a sure mark of separation between the two species. Locality: Station 113, 690 31' Dat. N., 70 06' Long. W., depth 1309 fathoms (temperature — iQ-oC), one fragment. These two Gclliodes-species differ from the hitherto known species by being possessed of toxa. Thus they show an approaching to the genus Toxochalina, but in this genus no sigmata should be found. Ridley and Dendy (Challeug. Report, Monaxonida, XX, 47) say that Gelliodes is only differ- ent from Toxochalina by the presence of sigmata in stead of toxa, and they continue: < It is perhaps doubtful whether the last character (sigma instead of toxa) is of generic value, and whether Toxo- chalina and Gelliodes should not be merged in one genus, but as no species is yet known, whose spi- cular complement comprises both toxa and sigmata, they may at present be kept apart . Now the two species described here show just this combination of toxa and sigmata, and consequently the genus Toxochalina, I suppose, must be merged in Gelliodes. I shall, hovewer, call attention to the fact that in the diagnosis of Toxachaliua the fibres are said to be <- rectangularly arranged , while, in the two species described here, they are irregularly branched, what seems upon the whole to be predominant in the Gelliodes-species. Oceanapia Norman. The sponge consisting of a round body from which more or fewer, branched or unbranched fistulce arise, which are closed at the ends. Outermost the body is surrounded by a hard, rindlike layer. Span gin present. Spicula: Megasclera diac final, oxea; microsclera sigmata. As mentioned under Phlceodictyon, I place Oceanapia under the Gelliince, as I regard it to be closely allied to Gelliodes. The character that separates it from this genus, would even seem chiefly to be the form only; but nevertheless the genus may, at all events for the present, be kept up. At present perhaps only the one species is known, as the only one of the three Oceanapia- species described by Dendy that is possessed of sigmata (Proc. of the Roy. Soc. Victoria VII, 1895, 248), O. mollis, according to its skeletal structure, is more likely to be a Gcllius, what Dendy himself so far directs the attention to, as he say's that it is very closely related to Gellius. Of the two species established by Topsent (Rev. Suisse de Zool. IV, 1897, 4^7, PI. XIX, fig. 13, PL XXI, fig. 29; 469, PL XIX, fig. 171, amboenensis and fragilis, the external form is not known, and both may perhaps be referred to Gelliodes. Of the Rhizochalina fibula ta established by Schmidt (Spong. Meerbus. v. Mexico, 76), nothing can be said on account of the incompleteness of the description'). 1. O. robusta Bow. PL XV, Fig. 1 a — c, Figs. 2 — 4. 1866. Isodictya robusta Bowerbank, Mon. Brit. Spong. II, 304, 20. 1866. Desmacidon feffreysii Bowerbank, Mon. Brit. Spong. II, 347, 2. mi the other hand, as will be seen hereafter, there is a possibility that Ridley and Dendy's O. robusta is not identical with the species of Bowerbank. The footnote of these authors under Rliizochalina fistulosa might likewise make it possible that here we had still another species of Oceanapia. PORIFERA. I. 1869. Oceanapia Jeffreysii Norman, Report Brit Assoc, for [868, 334 [874. Desmacidon Jeffreys//' Bowerbank, Mon. Brit Spong. Ill, 1^7, PI. PXII. 1882. Carter, Ann. Mag. Nat. Hist. Ser. 5, X, 121. 1885. Reniera tubzdosa Annauer Hansen (11011 Fristedt), The Norwegian North-Atlantic Exp. XIII, vSpongiacke, 4. 1887. lOceanapia robusta Ridley and Dendy, Challeng. Report, Monaxonida, XX, 36, PI. IX, fig. 3. 1887. Desmacidon Jc/j'rcysii Fristedt, Vega Exp. vetensk. Iakttag. IV, 442. 1892. Gelliodes cavicoriu's Topsent, Resultats des Campagn. scient du Prince de Mom co i c. II, 78, PI. Ill, figs. 4 et 9, PL IX, fig. 12. The sponge consisting of a rotmd body with more or fewer digitate, branched or unbranched hstuhv. which are closed at the ends. The surface slightly shaggy from projecting spicules. Outermost a hard, rindlike layer. The skeleton of the external layer an irregular network, chiefly of thick polyspl- enia r fibres. In the interior the skeleton consists of scattered needles. Spongin is found to a small de} in the fibres of the rind-layer. Splat la: Megasclera o.xea o-ju— 0-268""" ; microsclera slgmata ooi^nm. This species which, as is well known, is formed as a globular body from the surface of which branched or unbranched fistula arise, is in the collection only found in fragments, partly pieces of the external hard rind of the globular body, partly broken off fistnke. The largest piece which quite appears to be part of a globular surface, has a greatest extent of ca. 20cm; it is only convex to a slight degree, and must accordingly be a piece of a very large specimen. It has had several fistnke, but they are broken off; at their base they have had a diameter of 40 — 50mm. The thickness of the rind- layer is somewhat varying, about 10 — 15'"'". In fragments of smaller specimens the rind is considerably thinner, abont 2— 3'"'". Of the torn off fistuloe (belonging to the large specimen), some are unbranched, while others are divided into at most 4 or 5 digitate branches. The long fistulse have a length of ca. i3cm; towards the ends they are generally somewhat compressed. The diameters of the unbranched fistulce are at most ca. 20"1"1; but the branched ones are considerably thicker at the base. All the undamaged fistnke are closed as the ends, so that it seems that the fistnke are always closed. The colour of the sponge (in spirit) is light yellow. In the earlier descriptions the surface is stated to be smooth; this, however, is incorrect; it is even, but slightly shaggy from projecting spicules. As the specimens in hand chiefly consist of pieces of the rind-layer, we have only comparatively little of the interior body. This interior consists of a peculiar, loose and papp) substance of a yellowish white colour; when this substance is dried it contracts to a very high degree, becomes dark yellow ami semi- transparent, reminding, as stated by Norman I.e., of wax, although not in consistency, as it is very hard. The pores are found copiously as well on the body as on the fistula in the- intervals between the spicules; they are measured to a size of about nni| o-057mm. No oscula are found, and it is doubtful how the facts are with regard to the excurrent canals. As mentioned the fistulse are closed at the ends, but here and in their whole outer part they show a peculiar structure, the dermal mem- brane wanting or being reduced, so that holes appear of the same size as the meshes in the skeleton below; I am, however, inclined to think that this fact is due onl\ to damaging, and if so, the pores of the skin must act both as incurrent and as excurrent openings, (hi account of the 1 ment of the canal system, I suppose, that it is the pores of the fistulse that act as excurrent openings. 8o PORIFERA. I. The canal system. In the outermost part of the rind subdermal cavities are found, often as horizontal canals into which the pores lead, and from these cavities canals go in through the rind; they are rather numerous, so that a great many round holes, generally of a diameter of i — 3"™, are seen on the inside of the rind-layer, when this layer is separated from the inner tissue1). These canals are lined by a thin membrane the spicules of which are gathered into bauds or fibres running parallel with each other, sometimes in the longitudinal direction of the canals, sometimes obliquely on, or across this direction. The canals continue through the interior body, the direction apparently being chiefly towards the centre; in the soft tissue they are surrounded by a membrane, so that, when the tissue is washed away, they appear as membranous tubes. This membrane is provided with a spicula- net of loose fibres, and innermost it is lined with the membrane mentioned above. Other canals, presumably the excurrent ones, come together and open into the fistulas, in the base of which they converge, and they continue in the inner cavity of the fistulse. The walls of the fistulse are provided with a dense plait of fibres; the wall is easily separated into two lamellae, of which the inner one is provided with the same kind of spicula-net of loose fibres as is found in the membrane surrounding the canals. The fistulse are inmost lined with the same membrane as that lining the canals, and it is provided with spicules in the same manner. The skeleton. In the rind-layer the skeleton consists of a network of rather thick, polyspicular fibres forming irregular, most frequently polygonal meshes (PI. XV, fig. 2). The thickness of the fibres is somewhat varying, but generally it is from 0-05 — o-imm. The meshes of this network vary very much in size in different places, and they are smallest inward; in these meshes are seen thinner poly- spicular, or quite unispicular fibres with an irregular course, and also forming an irregular network. In the network no distinction can be made betw-eeu fibres running towards the surface, and fibres running parallel to it; here and there longer and most frequently a little thicker fibres are seen, but they have also a quite irregular course. The spicules of this network are cemented bv a clear, not copious mass of spongin; it is especially observable where it unites the ends of the spicules, but in the fibres it unites the spicules in their whole length. Outermost a layer of spicules are found at right angles to the surface, and projecting a little, so that the surface of the sponge becomes slightly shaggy; these spicules frequently show a somewhat fanlike arrangement. Between the perpendicular spicules others are interwoven partly oblique to, partly parallel to, the surface; therefore the skin, when seen from the surface, shows a rather dense, irregular network of spicules intercrossing in all directions, and from which needles rise in a vertical direction. The dermal membrane rests on this network; it cannot be separated by itself, but the whole layer with the vertical needles is easily peeled This network is also cemented by a mass of spongin, not only found at the ends of the spicules, but in all places where the spicules touch each other. Inwardly the skeleton of the rind is absolutely sharply bounded from the tissue inside of it. In the interior body the skeleton only consists of scat- tered needles without any visible order; they impart no firmness to this tissue, neither is any spongin found here. As mentioned above, the canals crossing the interior body, are surrouuded by a membrane; this membrane has a skeleton of very loose fibres forming a network, the longest fibres of which run the longitudinal direction of the canal (PI. XV, fig. 3); also in this network the spicules are united '! It is these holes which are called oscula by Bowerbank I.e. 304, as he had only fragments of the sponge at that time. PORIFERA. I. by spongin which seems only, however, to unite their ends. The membrane forming the inmost lining of the canals, as before mentioned, has spicules loosely gathered into bands, the direction of which in relation to the canals may be varying (PI. XV, fig.4); no spongin is found here. When we have got a clear understanding of the structure of the skeleton of the rind and the walls of the canals, the skeletal structure of the fistuke is easily understood; the fact is that their external part is formed by the rind, or, to put it more exactly, by the outer layer of the rind which passes into the outer layer of the fistulae, and their interior layer is formed by the membrane surrounding the canals with its skeletal net of loose fibres. These two parts are comparatively loosely joined, and may easilj be separated. The external layer of the fistulae has a thickness of about 2"""; here the fibres are com- paratively powerful, and especially powerful ones appear running longitudinally; the meshes formed by the fibres, are also averagely larger than in the rind-layer of the body, so that fistula- upon the whole consist of a comparatively open plait of fibres. Outermost the same layer with vertically projecting spicules is found as on the other parts of the body. The inner layer of the fistulas is constructed in quite the same way as is the case in the canals, and innermost it is lined with the same membrane as these. The fistulae consist almost exclusively of fibres and membranes without any other tissue. The outer and inner layers are in the upper end more firmly joined, and here the inner membrane shows a great many holes, so that it is reduced to a network; by this feature the pores on the fistulae are made to lead more or less directly into the inner cavity. It is not difficult to understand that these fistuke can act as oscula, for the water streaming forth through the excurrent canals, is poured into their inner cavity, and from the upper part of this cavity it is emptied out through a great main pores; thus the whole collection of pores serves to remove the quantity of water which would else have to be removed through a single osculum. Spicula: a. Megasclcra are oxea, slightly, not rarely a little irregularlv curved, with sharp, not long points, most frequently bounded by straight lines. Their length is generally between 0-20 — o-26n but it seems to be somewhat varying, as in a specimen from station S3 the length frequently is 029S the most common length is 0-23 — o-26mm. Ridley and Dendy, 1. c, state the length of oxea in Bowerbank's original specimen to be 0-19 — o-25mm. The thickness is o-oo8 o-oi28mm. Shorter and finer needles occur, but only singly; in the interior tissue, however, they are in some places seen in no small numbers, b. Microsclera: only one form, viz. sigmata; these are very small and oi a rather constant size; the length is averagely o-oi.i'nm, sometimes up to nin;':l", the thickness in the middle i.- about crooimm. Boverbank gives the length as — ^ inch = o-oi2mm. Ridley and Dendy, on the other hand, give the length of the sigma to be o-038""", and the thickness o-0032mm; this size ot the sigmata would almost seem to make it doubtful, whether Ridlej and Dendy's species is 0 robusta, or perhaps an allied species. Sigmata are found throughout the sponge, but are especially frequent in the membranes, as well the dermal membrane as the membranes oi the canals, and also in the inner tissue. As Topsent has .sent me a piece [fragment and fistulae) of the Ge Dili's establis by him I.e., I have been able with certainly to decide that it is Oceanapia robusta. Professor Top- sent has also in a letter declared that he thinks the two species to Ik- identical. - As I have had occasion to examine a piece of the specimen mentioned by Fristedt I.e. which, with some misgivin Pin' Ingolf-Expedition. VI, r. 82 PORIFKRA. I. he refers here, on account, as it would seem, of his not having seen the spicules, I have been able with certainty to decide that it is Oceauapia robusta. Remarks. In this species we find the so-called ^cellules spheruleuses to be especially conspicuous, partly because they occur in large numbers, and partly on account of their being rather large. They are especially found in the interior body, and on the membrane that lines the inmost part of the canals (PI. XV, fig. 4). The}- have an average size of cro2im'n. Their form is most frequently roundish, hut they are not rarely produced at one end so as to become pyriform, or at both ends, being then more or less fusiform. They are filled with clear, somewhat refringent granules, and are (in spirit) of a light yellow colour. Most frequently they are very conspicuous, and have therefore also been ob- served by Bowerbank, who calls them gemmules^, and mentions them I.e. II, 349 and more fully in 1S74, 1. c. Ill, 160 where he mentions that they are filled with granules, and gives their size to 1500 inch = o-oi -tun / Locality: Station 1, 62 " 30' Lat. N., 8° 21' Long. W., depth 132 fathoms (fragments and fistulae of a very large specimen); station 10, 64° 24' Lat. N., 28° 50' Long. W., depth 788 fathoms (fragments of a smaller specimen); station 78, 6o° 37' Lat. N., 270 52' Long. W., depth 799 fathoms, and station 83, 620 25' Lat. N., 280 30' Long. W., depth 912 fathoms (a few torn off fistulae). Geogr. distr. Originally this species was only known from the Shetland Islands from a depth of 70 — 90 fathoms. Later it has been taken in Soguefjord on the western coast of Norway, depth 650 fathoms (The Norwegian North-Atlantic Expedition); the fact is that I have been able, as I have had Armauer Hansen's original specimen, with certainty to refer to the present species the Reniera tubulosa mentioned by him I.e. Armauer Hansen perceives the resemblance himself, but says that his species has no sigmata; these however, he must have failed to see, as they are found copiously in his specimen. Further it has been taken at East-Greenland, depth 180 fathoms (Fristedt). — Including the localities in which the species has been taken by the Ingolf, it has now been found across the Atlantic, as we have the places Sognefjord, the Shetland Islands, the Faroe Islands, south and west of Iceland, and at East-Greenland. The species, however, reaches far more to the southward having been taken at the Azores, depth ca. 70 fathoms (Gelliodes cavicomis Tojjsent I.e.). Ridley and Dendy in Challenger Report mention it from Bermuda or Bahia (the locality is uncertain), but, as before said, there is some doubt of the identity of the species. Subfam. 2. Desmacellinae. Biemma Gray. The /<>nu varying, irregular, bat often compressed, or more or less leaf-shaped. The skeleton consists of a more or less irregular network of spicules, or of fibres that are most frequently not very marked, and reach no great length. Spongin (most frequently or always) wanting. Spicula: Mega- sclera monactinal, tyloslyli or suhtylostyli ; microsclera sigmata, or sigmata and toxa. 1. B. rosea Frstdt. PI. VI, Figs. 1— 2, PI. XV, Fig. 5 a— d, Figs. 6-9. 1887. Desmacclla rosea Fristedt, Vega Exp. vetensk. Iakttag. IV, 439, PI. 24, figs. 32 — 35, PI. 28, fig. 13. PORIFERA. I. 83 1892. Biemma Dautsenbergi Topsent, Resultats des Campagn. scient. du Prince de Monaco, Fasc. II, 83, PL III, fig. 5, PI. IX, fig. 16. More or less irregularly leaf-shaped. The dermal membrane thin, without spicules, resting on spicules spreading in a penicillate way and projecting. The surf die accordingly finely shaggy. Oscula numerous, small, only on one side. The skeleton an Irregular network 0/ spicules and loose fibres, from which short fibres go vertically to the surface. Spongin wanting. Spicula: Megasclera long, slender tylostyli or suhtylostyli. o,20j—oSpmm; microsclera contort sigmata O'OIJ — oojmm. Of this species we have no complete specimen, but a great many larger or smaller fragments which give, however, mainly information as to the external form of the species. By far the greatest number of the fragments are plate- or leaf-shaped, and generally somewhat arcuate, often in an ir- regular way; only a few are epiite irregular, and then the) show a concave and a convex side, being of a somewhat calicular form. The largest specimen lias an extent of 12"" in one direction by 8 — g"n in the other. A comparison of the separate fragments conveys the decided impression that this leaf-shaped sponge has been spread more or less horizontally; the irregular, somewhat calicular pieces are, no doubt, the middle parts, and by these the sponge has been attached; a single one of these pieces even shows a short stalk, which is seen to have been attached. Then from these middle parts the sponge has extended in a disc-like manner, more or less horizontally; thus, perhaps, it has assumed a very flat calicular form. The before mentioned largest piece conveys the impression of being a cut from about the middle to the edge; if so, this specimen would have been of a diameter of about 20cm. The thicknes.s varies between about 10 and 3mm; it is greatest towards the middle, and decreases towards the edge; the irregular middle parts may be somewhat thicker. A little specimen from station 89 has a different form, as a very thin in- crustation on a Hexactinellid-skeleton; this specimen the greatest extent of which is ca. 20mm, I take to be a quite young individual. The surface is quite finely shaggy from the projecting spicules. The consistency is rather firm. The colour (in spirit) varies between yellow and brown1). The dermal membrane is thin and transparent, and is supported by spicules spreading in a penicillate way, and piercing it. Oscula and pores: Where the surface is quite undamaged and the dermal membrane consequently present, close-set, most frequently circular openings may be seen on .me side of the sponge with the naked eye, or by means of a magnifying glass; their size is a little varying, generally it is 0-5 — i"'-"'. The dermal membrane rises a little round these openings, and shows a circlet "I projecting spicules. On the other side of the sponge no openings are seen. The mentioned openings are oscula which accordingly are only found on one side. When this oscular side is examined under the mil scope, the openings are seen to be of very different sizes, and the) have been measured quite down to o-o29mm; but this fact is obviously only due to a different degree of closing, the tact being that the smaller the opening appears, the broader is the thin membrane that surrounds the osculum and shuts the canal, of which the osculum is the excurrent opening. There is, however, some constant differ< in the size of the oscular opening, which difference is dependent on the width oi the canal. The ') All the pieces from station 10, ami most of those from statio ilmosl quite Hack. This tact 1 l>e due to a staining, hut as thej an- not known to have been in spin with animals from which tin got tin- colour, it would seem thai tin- sponge m.n sometimes get the black colour in PORIFKRA. I. other side of the sponge that has no oscnla, is the pore-side. The pores are here very close-set, they are more or less circular, and are lying in groups in the fields formed between the bundles of spicules that are spread in a penicillate manner. Their size is between 0-03 — croc/"™. In this species pores and oscula are thus execlusively localized each to their own side, and in connection with this fact the two sides show a somewhat different structure of the skeleton. To judge by the specimens in hand it seems to be the more or less convex side that is provided with oscula; it was to be expected that the convex side was the one turned downward or outward, and then oscula would be found on the outside; but whether this be the fact cannot be decided, until a whole specimen is obtained for examination. The skeleton consists of an irregular network of spicules crossing each other in every direction, and between them loose fibres are found. Spongin is not observed. Towards its two surfaces the skeleton, however, has a particular structure, short fibres being found here running more or less ver- tically on the surface; in the outer end of these fibres the spicules spread in a penicillate or funnel- shaped way, and pierce the dermal membrane. When these fibres are not vertical on the surface, they generally bend a little arcuately outward towards the outer edge of the sponge. As said before, there is some difference between the two sides; on the oscular side these fibres which support the dermal membrane as columns, are shorter and thinner, accordingly they generally consist of fewer spicules, and they are closer together than on the pore-side. On this side where the columns are somewhat longer and farther from each other, we therefore see in a transverse section just below the skin a great many subdermal cavities separated by the columns; in reality they all form presumably one large subdermal cavity. Also on the oscular side the skin is supported by the columns, so that we also here find a cavity, but a much smaller one, below the skin (PI. XV, figs. 8 — 9). The skin on the pore side comes off very easily, and when it is off the numerous incurrent canals are seen; they are of the same width as the excurrent canals, and in pieces where the dermal membrane is wanting, we may easily be led to suppose that oscula are found on both sides. The incurrent canals and the ex- current ones go, each from their side of the sponge, through it almost to the opposite side; they are often somewhat bent, and also often branched; they are of the same width, in the principal canals it is ca. r'nm. In the irregular middle parts of the sponge the canals have also a more irregular course. Spit it la: a. Mcgasclera. These are long and slender subtylostyli or tylostyli. Sometimes they are straight, but more frequently slightly curved; the curve may be somewhat varying, and is not rarely found nearest to the head end. The head may be marked off to a different degree from a 1 cely perceptible swelling to a fully developed, round head, so that the needle becomes a marked tylostylus; sometimes the swelling is found a little before the end. The other end is evenly produced to a long, rather fine point. The needle is thickest in the middle, also tapering somewhat towards the head end. The size of the needles is very much varying; the most common length seems to lie between o-65mm and o-jjmm, but it may increase to o-8o,mm and go quite down to o-203'nm, which is the smallest size I have measured. Like the length the thickness is also very much varying; the largest spicules have in the middle a thickness of o-oij"™, and the smallest go down to o-oo4mm. Upon the whole the thickness is in proportion to the length, but among the longer forms rather thin ones may dso be found. Quite fine spicules, developmental forms, are found of different lengths, but in small PORIFERA. I. numbers. 1). Microsclera. Only one form, sigmata, is found. These are rather thin and almost always contort, up to a quarter of a turn. Their length is between iroij— 0-028""", sometimes they may reach 0'03"""; the thickness is cool""" in the larger ones, the smaller are a little fin< 1. As I have had a piece of the original specimen of Fristedt, I have been able to identify the species with certainty. Fristedt gives the length of the tvlostyli to o-5""", hut in the original speci- men before me I have measured it to 077'""'. Fristedt dues not mention an oscular side and a pore- side, the reason being, I suppose, that the dermal membrane has been wanting on the pore side of his specimen. With regard to the columns supporting the dermal membrane he says: The dermis is furnished with numerous funnel-like depressions, which by degrees are closed, forming a fibre . From the above description I suppose it will be possible to understand, what is meant by this peculiar, not quite correct mode of expression. — The Bieimua Dautzenbergi established by To]) sent 1. c. must, according to the description, be identical with B. rosea. Topsent to whom I have sent a piece, declares also in a letter that he supposes them to be identical. Locality: Of this rather interesting species the Ingolf Expedition has brought home a great many larger and smaller fragments, probably, however, only representing few specimens. Station 9, 64° 18' Lat. N., 27- 00' Long. W., depth 295 fathoms; station 10, 64 24' Lat. N., 28 50' Long. W., depth 788 fathoms; station 73, 62 58' Lat. N., 23 28' Long. W., depth 4S6 fathoms; station 89, 64 45' Lat. X.. 270 20' Long. W., depth 310 fathoms. All these stations are off the souhwestern coast of Iceland. Geogr. distr. Fristedt has the species from East-Greenland, depth 125 fathoms; thus as arctic it has hitherto only been found in the Denmark Strait with a bathymetrical range from 125—7^8 fathoms, but this species also belongs to those found farther southward, having been taken on the expedition of the Prince of Monaco in 18SS (Topsent 1. c. B. Dautzenbergi) at the Azores 011 a depth of ca. 735 fathoms. 2. B. annexa < >. Schmidt. PI. IV, Fig. 14, P1.XVII, Fig. 3 a— f. 1870. Desmacella vagabuuda var. annexa O. Schmidt, Spongienf. atlant. Gebiet 53. 1S74. Desmacella pumilio Carter, Ann. Mag. Xat. Hist. Ser. 4, Vol. XI Y, 250, PI. XV, fig. 42 a, b, c. 1875. Desmacella vagabunda var. annexa O.Schmidt, Jahresber. d. Comm. zur wissenschaftlichen I'm d. deutschen Meere in Kiel fur 1872—73, 1875, 117. 1880. Desmacodes vagahin/dns var. annexa Vosmaer, Notes from the Leyden Mus. II, 108, 15. 1887. Desmacella annexa Ridley and Dendy, Challeng. Report, Monaxonida, Vol.XX, 1890. Biemma Cln t •rcuxi Topsent, Bull.de la Soe.de France, Vol. XV, 32. [892. Desmacella annexa Topsent, Resultats d. Campagn. scient. du Prince de Monaco, Fasc 11, 84, PI. IX, fig. :8. 1896. Desmacella annexa Topsent, Campagne de Caudan dans le Golf de Gascogne. Ann. de l'Ui versite de Lyon, XXVI, 281, PI. 8, figs. 5— 6. Oj an irregular form, incrusting, or 1110 ess massive. The dermal membrane thin, without spicules, resting on the projecting spicules that are spread in a . ingly ////civ shaggy. The skeletal/ consists oj short /Hires chiefly running towards the s gg t'ORIFERA. I. tiered spicules. Spongin wanting. Spicula: Megasclera long, slender tylostyli 0-22— roj""" ; micror- sclera trichoform toxa 008^—0-114""", sigmata of two sizes, 0-025— 0-028™*" a"d 0-014""". < )f this species we have a rather whole specimen and two smaller fragments. The whole specimen is all but leaf-shaped, bnt with irregular smaller folds, and irregularly arcuate, so that one side is somewhat concave. The outline of the specimen is about triangular; one edge has been at- tached, while the two free edges are somewhat irregularly lobed and bent towards the concave side. The height of the specimen is somewhat more than 50mm, and the thickness that is somewhat varying, reaches to io,nm. The colour (in spirit) is light grayish. As in the j^receding species the dermal mem- brane is supported by projecting, penicillate bundles of spicules, and consequently the surface is finely shaggy. As the surface is damaged in most places, I can say nothing definite with regard to the distribution of oscula and pores\ the pores seem to be found on both sides, but the specimen shows no oscula. The skeleton is somewhat more richly provided with fibres than in the preceding species; it consists of fibres chiefly running upward and bending towards the surface, so that they never grow long; between the fibres needles are found scattered in all directions. The ends of the fibres spread in a penicillate way, and pierce the dermal membrane which they support, as in the preceding species. Topsent says I.e., 1896, p. 283: membrane spiculeuse reticulee , but the dermal membrane itself has no spicules (with the exception of microsclera), it is only supported by the above mentioned bundles of spicules. Often these bundle- are not situated vertically on the surface, but, as a conse- quence of the direction of the fibres, thev are directed upward towards the upper end of the sponge, so that, when the dermal membrane is viewed from above, fan-shaped, somewhat decumbent bundles are seen. No spongin is observed in the skeleton. Spicula: a. Megasclera ; these are long, slender tylostyli, almost always a little curved, especially towards the head end. Generally the head is distinctly marked and rather round; the opposite end tapers to a rather long and fine point. The length of the needles is much varying, the most common length of the longest (fully developed) ones is between 0-83 — o-o/nm, but the length may increase to rc>5mm. By even transitions the size goes down to 0-22""", which is the smallest measured size. The thickness of the large needles varies from 0-014 — croi imm, while in the smallest ones it goes down to cvoc>5mm. Thus the needles are a little finer than in the preceding species; they are almost not fusiform at all, as they do not at all taper, or only taper to a slight degree, towards the head. b. Microsclera: 1. Toxa: these are very fine, trichoform. and have a flat curve in the middle, and a similar one a little from .each end; all three curves are very flat, and Schmidt therefore mentions these bows as ' feiue umspitzige Nadeln and Vosmaer as ac2. Otherwise the curve is sometimes a little irregular. The length is between 0-085 — crii4mm, and the thickness in the middle is ca. o-ooimm. These bows are ex- dingly abundant everywhere in the sponge, and are also found in the dermal membrane. 2. Sig- mata; these occur in two different sizes; the ends of the largest are most frequently curved with a more or less sharp bend, they are plane, or more or less contort up to a quarter of a turn; their length is rather constant 0-025 — 0'028mm, and the thickness is ca. O'0O2mm. The small sigmata are always some- what contort, their length is o-oi4'nm, and the thickness ca. o-ooimm. As the toxa, both kinds of sigmata are found throughout the sponge, but not in so large numbers. PORIFER The measures given here for the spicules of this species, agree with those given by Topsent (I.e. 18961 for specimens taken by Caudan , but, as men- particularly mentioned by Topsent in the place cited, the spicules of the species appear to be subject to some variation; thus he mentions spe- cimens in which the tylostyli only reach a length of < >\s' : also the small sigmata seem sometimes to be quite wanting, or, on the other hand, sometimes to be found in somewhat larger numbers than the large ones; the size of toxa, on the contrarv, is constant. Biemma annexa was first mentioned by Schmidt I.e. as a variety of his Desmacella vaga- hiiuda ; Vosmaer, in 1880 I.e., supposes it to be a separate species, but it was first established as a separate species by Ridley and Deudy in 1887. Topsent who in [890 1. c, reestablishes Gray's genus Biemma for the forms belonging here, which forms are distinguished from Desmacella by the halichondroid structure of the skeleton, first refers tin- present species mink; the name of Biemm ■ Chevreaxi. as he took it to be a new species) to the genus Bi mma. but in [892 I.e. he says that .in account of the presence of toxa it belongs to the genus Desmacella. In the occurrence of toxa I cannot, however, see any reason for referring it to Desmacella; on account of its skeletal structu which by the only little marked fibres and by the want of spougin quite agrees with that of the other Biemma-species, it has just to be referred to the genu.-- Biemma. Locality: Station 97, 65 28' Lat. N., 27° 39' Long. W., depth 450 fathoms, one specimen and two fragments. Geogr. distr. This species has a wide range north of the equator having been found from about ca. 18 Lat. X. up to 65 28' Lat. N. As to bathy metrical range it has been found on depths from 500 fathoms to ca. 21 fathoms. The Antilles, depth 390 fathoms (Challenger); Florida, depth 1 onis (Schmidt); in the Mediterranean in the Gulf of the Lion on depths of ca. 60 — ca. 21 fathoms, at the coast of Asturias, depth ca. 66 fathoms: in the Gascom Kay, depths ca. 345 fathoms and 500 fathoms, and southwest of Belle-Isle, depth ca. 60 fathoms (Caudan |; in the western entrance of the English Channel, depth 500 fathoms (Carter); at the western coast of N'orwa\ southwest oi Bukenfjord, depth 106 fathoms; and finally in the Denmark Strait 65 28' Lat. X.. 27 39' Long. W., {.50 fathoms (Ingoif). Note. Topsent, in 1892 enumerates the until then described Biemma-species, and mention- four: B.inoniata Bow., comigata Bow., Grimaldii Topsent, and Dautzeiibergi Topsent. As before said, Dantzenbergi is synonymous with rosea Frstdt. In the present work 1 further refer annex- Schmidt to this genus. Finally the Gellitis iii/'iuidibitli/ormis. establish Vosmaei (Sponges of Willem Barents , Bijdr. tot de Dierk. i2te Ail, 3'Kc Gedeelte, 29. I'l. I, fig. 13. PI. IV, figs. the spiculati of which is tylostyli and sigmata, will probably have in !>e referred to this genus. Thus at present the genus Biemma appears to comprise the following species: Biemma inoniata Bow corrugata Bov — amiexa * >. Schmidt. — rosea Frstdt. Grimaldii Topsent. iiifuiidibuliformis Vusw SS PORIFERA. I. Desmacella O. Schmidt. The form varying, massive and irregular, or erect and of a more definite form, leaf-shaped or more or less calicular. The skeleton consists of long, well developed branched fibres, the spicules of which are united by a most frequently slight ///ass of spongin. Spicule/: Megasclera monacfinal. styli (some- times tylosty/i); microsclera may be combined in various ways, sigmata alone, or sigmafa of two to three sizes, and rhaphides of one to three sizes, and most frequently small comma-shaped styli (commata) (per- haps always fo/t /id at this combination of spicules) or finally rhaphides alone. Of this genus we have several species, all, however, nearly related to each other; these species are grouped round Desmacella PcachiiBow., and agree in the fact that with regard to microsclera they have sigmata at least of two sizes, rhaphides of one or more sizes, and all, I suppose, small comma- shaped styli. The question whether we have here one varying species or several species, may be rather difficult to decide; the spicules, however, seem here, as in other places, to give rather sure and constant species-characters, even if the differences are small. It may also give rise to some diffi- culty to decide whether any of the species in hand and if this is the case, then which of these species — are identical with earlier described species, as the difference of the spiculation and the forms of the spicules are not given with sufficient distinctness in the earlier descriptions. When in the following I have determined one of the species before me as Bower bank's D. Peach ii, I have there- fore made this determination with some reservation. i. D. capillifera Levinsen. PI. XVI, Fig. i a— g. 1886. Gellius capilliferus Levinsen, Dijmphna Togtets zool.-bot. Udbyttet, 357, Tab. XXX, figs. 7 — 10. 1896. Desmacella Peachii var. groenlandica Lambe, Sponges from the Atlant. Coast of Canada, Trans- act, of the Roy. Soc. of Canada, Ser. 2, II, Sect. IV, 186, PI. I, figs. 5, 5 a— e. Form? The dermal membrane thin, only provided with microsclera. The skeleton consists of powerful fibres with little spongin, Spicula : Megasclera styli o-j — f> Branches from the fibres bend everywhere outward, and support and pierce the dermal membrane, as before mentioned. The spaces between tin- fibres are filled by an irregular network of the fii branches and anastomosiugs. The spicules of the fibres are cemented b\ spongin which is not. how- ever, seen to coat the whole fibre. The spongin is seen especially distinctly where branches go from the fibres. Spicula: a. Megasclera are styli, more or less, oftenest slightly curved, and almost always with the curve nearest to the upper end; the other end runs into a long, evenly tapering point, the outer- most end of which may be more or less shortly pointed; especially in the shorter and thicker spicules the point is often short. The length is somewhat varying, from about £-5 in this respect some 92 PORIFERA. I. difference ma) be found between different individuals. The thickness at the upper end is between 0-029 — 0-039""", the longest generally not being the thickest. Considerably finer needles of about the sank' length, and connected with the others by transitions, may be found, but only in small numbers. Besides normally formed styli forms may rather frequently be found, in which the pointed end is rounded, and then it may be thinner or thicker, so that we get strongyla. As in the preceding species I have also in the present one down at the place of attachment found irregularly formed, more or less sinuous and curved needles, upon the whole smaller than the normal needles of the species. b. Microsclera. 1. Sigmata of two sizes: the larger ones have a regularly bent shaft, and the ends are recurved with a round bend, and form a rather large hook. These sigmata are always contort, generally about a cjuarter of a turn. The length is rather constant, and is between 0-09 — o-iomm; the thickness is 0-0035— 0-004""". Also finer sigmata, down to quite fine ones, are found, which no doubt are developmental forms; they are of the same length as the fully developed ones. Besides being found single, these sigmata very frequently occur in bundles, sigmadragmata, and presumably they are ill developed in this way. As far as I have been able to decide, each bundle contains always eight sigmata; frequently bundles are seen made up of fine sigmata, but generally they have the full thickness, and consequently the bundles are not disunited, until the sigmata are fully developed. The small sigmata have a regular sigma-form; their length varies from 0-016 — o-02i'nm, the thickness is ca. o-ooi""". They are never seen in bundles. 2. Rhaphides of two sizes: longer and shorter; the longer rhaphides are hairlike and finely pointed, of a length of 0-15 — 0-17""" and a thickness at most of o-oojmm These rhaphides may be seen singly, but they occur chiefly in bundles, trichodragmata, which seem to be of a very varying thickness. The smaller rhaphides are somewhat thicker than the longer "lies, and they are fusiform; sometimes the greatest thickness is nearest to one end. The length varies from 0-042- o-057mm, but most frequentlv it is 0-05""", the thickness is 0-0015— o-oo2,nm. These rhaphides 0 occur in bundles, trichodragmata; the bundles are often seen to contain eight rhaphides, but there seem also to be bundles with more needles. 3. Commata, small, comma-shaped styli of a similar form as in the preceding species; the head end is slightly swollen; the length is o-on — o-oi4min, and the thickness at the upper end ca. o-ooimm. All the microsclera occur as well in the dermal membrane as in the other tissue; of the two forms of sigmata the smaller are everywhere most abundant. ( } mi inn lie .' Besides the silicious bodies mentioned before we find in this sponge a particular form, viz. small silicious globules. There is, however, the peculiarity of the occurrence of the globules, that they are not found in all individuals, and in the sponges where the}- are found, they occur only in certain places, so that in many cuttings of the sponge they are not seen at all, while in others they are found in great abundance. There can be no doubt that these globules belong to the same kind oi bodies as will be mentioned below under D. groe nlandica Frstdt, and which I take to be gemmuke; thus the fact that they are not found constantlv, may also be understood, as an individual need not 11 times have these bodies. In the present species I have not found them to form distinct round -uke, but have only found them scattered singly in the tissue, or in irregular loose heaps. These globules vary in diameter from 0-004 — o-oo8mm. ality: Station 53, 63 15' I,at. X., 15° 07' Long. W., depth 795 fathoms, a couple of small spe- I'ORIFERA. I cimens; station 92, 64 \.\' Lat. X., 32 52' Long. W., depth 976 fathoms, fragments of a larger specimen; station 95, 65 14' Lat. N., 30 39' Long. W., depth 752 fathoms, two quite small specimens and a I fragments; station 96, 65 24' Lat. X., 29 00' Long. W., depth 735 fathoms, two smaller specimens; it has further been taken on the East-Greenland expedition [891 92 on 65 39' Lat N., 28 25'Long. W., depth 553 fathoms, one specimen. These stations are all situated in the Denmark Strait, excepting station ;,} that is off the south coast of Iceland. Geogr. distr. Of this sponge hitherto only two specimens have been known, one taken at Scot- land (the original specimen of Bowerbank) the other in the English Channel at Luc (Topsent). Un- fortunately no depth has been given lor either of these localities. 3. D. hamifera n. sp. PI. VII, Figs. 4—6, PL XVII, Fig. 1 a 1. Leaf?- or funnel-shaped. The surface with small conical processes, formed by the projectin The dermal membrane thin, only provided with microsclera. Oscula scattered. The skeleton consists powerful polyspicular fibres branching /rum the base up through the sponge, mid connected by trans: anastomoses. Spongin is found cementing the spicules, but only to a rather ^mall degree. Spicula : Megasclera ttyli o'j$ — v^6mm; microsclera sigmata of two sizes, large ones of a peculiar form, most fre- quently as dragmata 0-08 — o'iojmm, small ones o'oi/j. — o'02imm; rhaphides us trichodragmata long, hair-like ones ovj — o'i6mm, short ones o'o^j- o'o6mm; commata omoii — o'oij. This species is of a quite similar form and structure as the preceding one. The specimens in hand have an erect, leaf-shaped form; a single one shows a short, thick stalk which has been attached, and which has at the top the remains of an open funnel (PI. VII, fig. 5). None of the specimens, however, are quite undamaged, so that there may be some doubt whether the species is always funnel- shaped, or perhaps also may be leaf-shaped. The largest specimen, a somewhat concave-convex leaf, has a height of I2cn', and a similar breath; the thickness in the middle of the leaf is aboul 20mm. The thickness is greatest below where the sponge has been attached, and decreases towards the uppei edge. The other specimens are all somewhat smaller, also leaf-shaped, but most of them are a little arcuate, so that the probability is that the sponge is funnel-shaped. A single fragment is attached to a stone. The consistency is rather firm, hard clown towards the place of attachment. Tin- colom (in spirit) varies between light yellow and light gray. The tin- mat membrane is also in this species sup- ported by the ends of the fibres, and so the surface shows the same kind <>i small processes as in the preceding species. The dermal membrane is otherwise only kepi lieu and there in .1 few of the specimens. It shows, at all events in some places, a quite peculiar structure. When viewed under a lens, it shows a network resembling .1 network of spiculo-fibres, as foi instance in H.panicea; but und higher magnifying powers it is seen that the network is made by the formation of thicker strings in the skm inwardly; the- network incloses roundish or oval thin-skinned fields, and in these fields the pores are lying in different numbers. In the strings of the network some roundish or fusiform cells are seen filled with refringent granules (cellules spheruleuses Tops.). This structure of the skin, howevei is not found everywhere, the skin in other places appearing as a simple thin membrane without an) 92 rnkll'KRA. I. difference maj lie found between different individuals. The thickness at the upper end is between _>g — 0-039""", the longest generally not being the thickest. Considerably finer needles of about the same length, and connected with the others by transitions, may be found, but only in small numbers. Besides normally formed styli forms may rather frequently be found, in which the pointed end is rounded, and then it may be thinner or thicker, so that we get strongyla. As in the preceding species I have also in the present one down at the place of attachment found irregularly formed, more or less sinuous and curved needles, upon the whole smaller than the normal needles of the species. b. Microsclera. i. Sigmata of two sizes: the larger ones have a regularly bent shaft, and the ends are recurved with a round bend, and form a rather large hook. These sigmata are always contort, generally about a quarter of a turn. The length is rather constant, and is between 0-09 — o-io'm"; the thickness is 0-0035— o-oo4mm. Also finer sigmata, down to quite fine ones, are found, which no doubt are developmental forms; they are of the same length as the fully developed ones. Besides being found single, these sigmata very frequently occur in bundles, si^madragmata, and presumably they art- all developed in this wax. As far as I have been able to decide, each bundle contains always eight sigmata; frequently bundles are seen made up of fine sigmata, but generally they have the full thickness, and consequently the bundles are not disunited, until the sigmata are fully developed. The small sigmata have a regular sigma-form; their length varies from 0-016 — o-02i'nm, the thickness is ca. 0-OOiram. They are never seen in bundles. 2. Rhaphides of two sizes: longer and shorter; the longer rhaphides are hairlike and finely pointed, of a length of 0-15 — 0-17""" and a thickness at most of 11™, These rhaphides may be seen singly, but they occur chiefly in bundles, trichodraginata, which seem to be of a very varying thickness. The smaller rhaphides are somewhat thicker than the longer ones, and they are fusiform; sometimes the greatest thickness is nearest to one end. The length varies from 0-042- 0-057'""', but most frequently it is 0-05""", the thickness is 0-0015— o-oo2,nm. These rhaphides also occur in bundles, trichodraginata; the bundles are often seen to contain eight rhaphides, but there seem also to be bundles with more needles. 3. Commata, small, comma-shaped styli of a similar form as in the preceding species; the head end is slightly swollen; the length is o-on — o-oi4mm, and the thickness at the upper end ca. o-ooi""". All the microsclera occur as well in the dermal membrane as in the other tissue; of the two forms of sigmata the smaller are everywhere most abundant. Gemmula? Resides the silicious bodies mentioned before we find in this sponge a particular form, viz. small silicious globules. There is, however, the peculiarity of the occurrence of the globules, that they are not found in all individuals, and in the sponges where they are found, they occur only in certain places, so that in many cuttings of the sponge they are not seen at all, while in others they are found in great abundance. There can be no doubt that these globules belong to the same kind of bodies as will be mentioned below under D. groenlandica Frstdt, and which I take to be gemmuke; thus the fact that they are not found constantly, may also be understood, as an individual need not at all times have these bodies. In the present species I have not found them to form distinct round uhe, but have only found them scattered singly in the tissue, or in irregular loose heaps. These lules vary in diameter from 0-004 — o-oo8mm. ality: Station 53, 63 15'Lat. X., 15 07' L,ong. \\\, depth 795 fathoms, a couple of small spe- I'ORM-KRA. I. 93 cimens; station 92, 64 44' Lat. N., 32 52' Long. W., depth 976 fathoms, fragments of a larger specimen; station 95, 65' 14' I, at. X., 30 39' Long. W., depth 772 fathoms, two quite small specimens and a few fragments; station 96, 65 24' Lat. N., 29 00' Long. W., depth 735 fathoms, two smaller specimens; it has further been taken on the East-Greenland expedition t8gi 92 on 65 39' Lat. N., 28 25' Long. W., depth 553 fathoms, one specimen. These stations are all situated in the Denmark Strait, excepting station 53 that is off the south coast of Iceland. Geogr. distr. Of this sponge hitherto only two specimens have been known, one taken at Scot- land (the original specimen of Bowerbank) the other in the English Channel at Luc (Topsent). Un- fortunately no depth has been given for either of these localities. 3. D. hamifera n. sp. PI. VII, Figs. 4 -6, PI. XVII, Fig. 1 a 1. Leaf?- or funnel-shaped. The surface with small conical processes, formed by the projectin The Ji rmal membrane thin, only provided with microsclera. Oscula scattered. The skeleton consists powerful polyspicular fibres branching from the base up through the sponge, and connected by trans: anastomoses. Spongin is found cementing the spicules, bat only to a rather smalt degree. Spicula : Megasclera ityh 0-7/5 — v$6mm; microsclera sigmata of two sizes, large ours of o peculiar form, most fre- quently as dragmata o-o8 — o-ioj"im, small ours 0-014 — cro2imm; rhaphides as trichodragmata long, hair-like ours o-/j — cri6""n, short ours O'O^j- o'o6mm; commata o'Oii — troij""". This species is of a quite similar form and structure as the preceding one. The specimens in hand have an erect, leaf-shaped form; a single one shows a short, thick stalk which has been attached, .mil which has at the top the remains of an open funnel (PI. VII, fig. 5). None of the specimens, however, are quite undamaged, so that there ma}' be some doubt whether the species is always funnel- shaped, or perhaps also may be leaf-shaped. The largest specimen, a somewhat concave-convex leal, has a height of I2cm, and a similar breath; the thickness in the middle of the leaf is aboul Hie thickness is greatest below where the sponge has been attached, and decreases towards the upper edge. The other specimens are all somewhat smaller, also leaf-shaped, but most of them are .1 little arcuate, so that the probability is that the sponge is funnel-shaped. A single fragment is attached to a stone. The consistency is rather firm, hard down towards the place of attachment The colour (in spirit) varies between light yellow and light gray. The dermal membrane is also in this species sup- ported by the ends of the fibres, and so tin- surface shows the same kind of small processes as in the preceding species. The dermal membrane is otherwise onh kept lure and there in a tew of the specimens. It shows, at all events in some places, a quite peculiar structure. When viewed under ,1 lens, it shows a network resembling .1 network of spiculo-fibres, a-- lot instance in 1 1, pauicea: but und higher magnifying powers it is seen that the network is made by the formation of thicker strings in the skm inwardly; the network incloses roundish or oval thin-skinned fields, and in these fields the pores are lying in different numbers. In the strings of tin network some roundish or fusiform cells art seen filled with refringent granules (cellules spheruleuses Tops.). This structure of the skin, however, is not found everywhere, the skin in other places appearing as a simple thin membrane without am g. PORIFERA. I. network1). Of spicules the skin has only microsclera, viz. rhaphides of two sizes, especially occurring; in bundles, but without any order; in some places especially the long ones are seen, in others the -hurt ones; where pores are seen, the bundles of rhaphides, especially the short ones, seem to be re- stricted to the strings between the thin-skinned pore fields, while long rhaphides are seen scattered singly also over the pore fields. Further sigmata of two sizes are found in the skin, of which the larger ones are found rather sparingly in most places, while the smaller are everywhere abundant; finally commata are also found abundantly. Oscula and pores: As before said, the pores are found in the thin-skinned pore fields to a number of about ten in each field; they were measured of a size of o-02Q, — ca. o-i2mn'. Where the skin was kept, here and there some circular openings were found of a diameter of 1-5 — 2m,n, which openings I take to be oscula. The skeleton is constructed in a quite similar way as in the preceding species. It consists of polyspicular fibres issuing at the base, and running up through the sponge. The fibres are thickest at the base, and reach here a thickness of 1 — rj"; in their branching upward they become somewhat thinner, and at the same time they become more richly branched. In a radial longitudinal section the more or less parallel or somewhat diverging longitudinal fibres are distinctly seen, thus being the principal fibres; the}- are connected by numerous transverse anastomoses. Outward towards each side the fibres send off branches supporting and piercing the dermal membrane (PI. VII, fig. 6). In the tangential direction the fibres diverge and branch somewhat more, on account of the fan-shaped or calicular form of the sponge. The spicules of the fibres are cemented by a distinct, but clear mass of spongin, which is most copious towards the base of the sponge, and which seems to coat the fibres entirely, although only with an exceedingly thin layer. Spiiiila: a. Megasclera are styli, more or less, sometimes somewhat irregularly, curved; they have a long tapering point, of which, however, the outermost end is shortly pointed. The length varies from 075 — i-56mm; most frequently it is between 1 — i-25mm. The thickness is between about 0024— o-036mm ; generally the length and thickness are in proportion to each other, although it is not always the case. Styli with a more or less broadly rounded point are rather frequently seen. Con- siderably finer needles which may be regarded as developmental forms, occur in small numbers. Also in this species we find in the layer touching the place of attachment irregularlv formed spicules of other dimensions than the other ones. b. Microsclera: 1. Sigmata of two sizes; the large sigmata have a peculiar form, being highly curved, and the curve is most frequently sharpest in the middle of the shaft, while the piece between the curve and the hook-shaped end may be more or less straight; the ends are finely pointed and recurved in a sharply hook-shaped way. These sigmata are almost always contort, most frequentlv about a quarter of a turn, but as well with regard to this feature, as upon the whole with regard to form, they may be somewhat varying. Their length, which is, of course, somewhat dependent on the degree of curving, is o-o8— o-ioj""", the thickness varies from 0-002— o-oo3mm. Quite fine forms, deve- lopmental phases, of the same length as the others, are also found. These sigmata are seen both 'I In these latter places no pores have been observed; it is possible that the mentioned structure of the skin is only the places provided with pores, and it is also possible that pores are only found in certain places and oscula in 5, but die material in hand has not been sufficient to enable me more particularly to elucidate this question. PORIFERA. I. gr singly and as sigmadragmata, which latter also in the present species seem always to be composed of eight sigmata. The small sigmata have a regular form, their length varies from 0014 — o-02in"n, the thickness is ca. o'cxn""", or still finer. These sigmata arc not contort, and they arc never seen in bundles. They are present in much larger numbers than the large ones. 2. Rhaphides of two sizes; the long rhaphides are hair-like and finely pointed; they have a length of <>i- . and their thickness is at most o-ooimm. These spicules may be found singly, but they occur chiefly in tricho- dragmata of varying thickness. The small rhaphides are thicker, fusiform, and of a length 1 — o-o6mm. The thickness is 0-0014 — 0-0017""". These rhaphides are found in bundles, which often seem to contain eight rhaphides, but mav also be composed of a greater number. 3. Commata; small, comma-shaped styli with a somewhat swollen head end; sometimes they are a little irregularly curved; their length is o-on— o-oi4mm, and the thickness at the head end is orx>i2""". All the forms of the microsclera are found, besides in the dermal membrane, also in the other tissue of the sponge in great abundance. Gemmulce? I have also in individuals of this species found gemmula-like bodies. Mosl irv- quentlv thev were here found as roundish loose heaps of silicious globules, but also as distinctly limited, more or less globular or roundish bodies, in which the silicious globules, it would seem, were lying in a membrane or inside of it (PI. XYII, fig. 1, 1). Generally these bodies had a diameter of ox>5 — o-07min. The silicious globules vary from 0-0015 — o,oo57mm. All the globules in one heap are of about the same size. In a few specimens these bodies were found especially abundantly. Locality: Bv the Ingolf expedition this species has been taken on station 1, 62 30' LaL N., 8 21, Long. W., depth 132 fathoms; station 2, 63 04' Lat. N., 9 22' Long. W., depth 262 fathoms; station 3, 63' 35' Lat. X., n« 24' Long. W., depth 272 fathoms; station 89, 64 45' Lat. X., 27 20' Long. \\\, depth 310 fathoms; station 97, 65 28' Lat. X., 27° 39' Long. W., depth 450 fathoms. It has further been taken 011 66 20' Lat. N., 25 12' Long. W., depth 96 fathoms; 63 15' Lat. X., 9 35' Long. W., depth 270 fathoms; 61 23' Lat. X., 5 04' Long. \\\, depth 255 fathoms (Wandel); and at the Faroe Islands, a little to the east of Sudero, depth ca. 150 fathoms (Th. Mortensen). In all about ten more or less damaged speci- mens or fragments have been taken. All the localities are situated at the Faroe Islands, between the Faroe Islands and Iceland, and in the Denmark Strait; and its bathymetrical range is between 96 and 450 fathoms. 4. D. groenlandica Frstdt. PI. VI, Fig. 14, PI. VII, Fig. 7, PI. XVII, Fig. 2 a h. 1887. Desmacella Peachii var. groenlandica Fristedt, Vega Exp. veteusk. Iakttagelser IV. 441, LI. 24. figs- 3s— 45) P1- 2,s> fig- L4- I'h, ton// calicular. The surface with small conical pro rmed by th the dermal membrane thin, only provided with microsclera. Oscula 'only on the inside?) small, r with papilla-like projections. The skeleton a ' fibres, up through th, richly branching ,/>/,! anastomosing. Spongin is found cementing the needles, but no: sly. Spicula: Megasclera styli opf—rj?"""; microsclera sigmata oj two ' :" 009- 96 PORIFERA. I. small ones omoo8—o,oimm; rhaphides of two sizes, most frequently in it 'rag main, the long ones 0-25 ,,\""". the short ours omo8 — in""": commata o-oo8mm. The only specimen in hand of this species has an open, somewhat irregular calicular form, and has been attached without any stalk. Its height is ca. 6cm, and its greatest breadth in the circum- ference 1 . while the thickness of the wall is scarcely 2C1". The surface is set with small processes due to the ends of the fibres. The colour (in spirit) is pale yellow. The consistency is less firm than in the preceding species. The dermal membrane is thin, and is supported by the ends of the fibres; of spicules it has only microsclera, viz. rhaphides of two sizes, partly scattered in the skin, partly oc- curring in bundles, and small sigmata, present in very large numbers. In some places of the skin was seen a similar structure with thinner fields as in the preceding species. In the present species oscnln have a quite peculiar structure their edge being provided with papilla;. When the osculum is open, it is a more or less round hole of a diameter of ca. o-5nim. When this is the case some slightly pro- jecting lobes are seen in the edge, and the ends of rhaphides project into the opening. When the osculum is being shut these lobes grow to longer and longer papillae, and the projecting rhaphides cross each other; at last the papillae come together, and the closed osculum forms a little conical process (PI. VI, fig. 14). Whether the papillae are free or only papilla-like folds of the skin, I have not been able to see. This way of closing the osculum is quite peculiar, and it is to be supposed that the function of the projecting rhaphides is to bar the entrance when the osculum is not closed. In the present specimen oscula are found abundantly on the inside; but as the skin of the outside is torn off it cannot be decided, whether they have been restricted to the inside, or have been found all over the sponge. Pores I have not seen; they must be supposed to be lying in the before mentioned thin-skinned fields. The skeleton is of a quite similar structure as in the two preceding species, and consists of fibres running from the base up through the sponge branching and anastomosing, and giving off branches towards the surface supporting the dermal membrane. The fibres are a little thinner, and seem to be somewhat more richly branched than in the preceding species. A distinct, clear mass of spongin unites the spicules of the fibres, and coats the fibres entirely, though only with a thin, scarcely observable layer. Spicula: a. Megasclera; these are slightly, or at the head end, a little more strongly curved styli with an evenly tapering point the outermost part of which may be a little more or less shortly pointed- The length varies from ca. 0-94 — i'37mm, and the thickness at the upper end is 0-025 — o-035m"'. Styli with more or less broadly rounded points are not scarce. Also in this species styli are found in the basal layer, smaller than the normal ones, and irregularly bent in different ways. b. Microsclera: 1. Sigmata of two sizes; the larger are of a quite similar form as in the pre- ceding species with a strong curve in the middle of the shaft and a little hook-shaped recurving of the ends; they are also contort. The length from one hook to the other is ca. 0-09 — o-iomm, and the thickness is o-oo28inni. These sigmata occur in very small number, and only quite singly, so that there might be some doubt, whether they really belong to the sponge or are extraneous; as, however, they 1'DRIFERA. I. 9/ are found in almost every cutting of the sponge, the probability is that thej belong to it. This lief is also favoured by the fact that they are mentioned by Fristedt as found in his specimen, which is, in spite of the scarcely quite correct figure of the large sigma, surely identical with the the species before me1)- The small sigmata are much smaller, than in the preceding species; they are of the common form, and are plane; their length is between cvooS— croi'm", and the thickness may be given as o-oooj"11" or still finer; these sigmata are exceedingly numerous, as well in the dermal mem- brane as throughout the sponge. 2. Rhaphides of two sizes, both considerably larger than the coi spondiug rhaphides in the two preceding species. The long rhaphides have a length of 0-25—0 and a thickness in the middle of ca. o-oo2'm". Their ends are produced into long tapering, fine points. They are always straight, and if some are seen to be curved, when a piece .if the sponge is examined under the microscope, the cause of this fact cannot be that they have such a form, but it must he due to a force acting on them. These rhaphides occur both scattered and in bundles containing a rather large number of rhaphides. The short rhaphides are fusiform, their length varies from croS — o-im,n, and the thickness is about cvoo28m,n. These rhaphides are chiefly found in bundles that seem most frequently to contain a rather large number of rhaphides. Both kinds of rhaphides are found abundantly as well in the dermal membrane as through the whole sponge. 3. Commata; these are only found in very small numbers, but like the large sigmata they are found in every cutting; they are small, their length being ca. croo8mm, and the thickness at the head end about erooi""". GemmidcB? In this species Fristedt mentions the same bodies as have been mentioned in the two preceding species, and which he takes to be gemmulae. He figures these bodies PI. 24, 1 44—45. In the specimen before me I have only seen the small silicious globules that are found in the wall of the mentioned bodies, singly or in small groups, while the piece of Fristedt's original specimen 1 have had for examination, shows the gemmulse-like bodies abundantly; they are most fre- quently quite globular, of a diameter of about cro8ram; they are formed of silicious globules imbedded in, or situated inside of, a membrane which is, perhaps, made of spongin; on the other hand I have not been able to find the depression in the wall mentioned by Fristedt 1 a small depression like- that in the globular spicules of Geodia ), and I suppose that it is not really found, but is only due to the refraction (PI. XVII, fig. 2 f). In the bodies that seem to be quite finished, the globules have a diameter of ca. 0-007""", while in others, mostly seen as loose groups of globules, it is considerably smaller, down to 0-002""", or still smaller. The globules of the same group are always of about the same size, so that all the globules belonging to one of the gemmula-like bodies, appear to be begun and developed contemporaneously. The reason win- these bodies have here been termed gemmulse, is only that they recall to some degree the gemmulse of the spongillee, and presumably serve the propagation of the sponge; it is only little probable that their function should be the same as that of the gemmulee of tin as the question is here of species from rather considerable depths (78 076 fathoms). Locality: The Denmark Strait (>o .10' I, at. X., 65 12' Long. W., depth 96 fathoms iW'audeb. one specimen. 'i Fristedt 1. c. does not mention that these sigmata are so small in numb< ' thej must sureh liav< m> also 111 his specimen, .-is 1 have not even been able t" find any largi piece <■' his specimen I have had foi examination, but then this piece also consisted almost only of nal The [ngolf-Expedition. VI i. '3 98 PORIFERA. I. Geogr. distr. Fristedt has the species (a small fragment) from the east coast of Greenland, depth 130 fathoms. Note. As before mentioned, the four Desmacellaspedes enumerated here, appear to be nearly related, showing great correspondence as well with regard to their skeletal structure and spiculation, as also their outer form and the structure of their skin seem to be corresponding. We might, perhaps, be justified in establishing a special genus for them, to which genus some more species would then have to be referred, as all species with rhaphides of one or more sizes seem to be nearly related, and must be grouped together. I shall here put together the hitherto described species that are possessed of rhaphides; with regard to the species not described here, I give the measures according to the authors in question: Desviacclla va riant ia Bow. ca pill if mi Levins. fortis Tops. Amboyna, The Read Sea. Peachii Bow. Peachii var. stelli- fera Frstdt. West-coast of Sweden hamifera mihi grot nlandica Frstdt. Peachi var. trirlia- phis Tops. Amboyna Peachi var. fistulosa Tops. Amboyna aberrans Tups. Megasclera Styli o'43 — 0'63mm 0'6 — i"Smm o-S7— 1-5" 075— 1 '56" 0-94— 1 -37" o'35n Microsclera Sigmata o-3— °"33n 0'6mra Two sizes: large: 0-064— o-oSsmm small: 0-012 — o'025mm Two sizes: large: 0-04—0-11™ small: 0-019— o-03imm Two sizes: large: 0-09 — 0"io5mm small: o-02mm Two sizes: large: 0-09— o-iomm of common form, small: 0-016 — o-02imm Two sizes: large: ca. o-i2ram of common form, small: ca. o-oi5mm Two sizes: large: 0-08—0-1071™ of peculiar form, small: 0-014— o'02lmm Two sizes: large: 0-09 — o-iomm of peculiar form, small: o-ooS — o-oimm Three sizes: largest: o-o8mm middle: 0'045mm smallest: o-oi8mm 0-015— 0-05S" Rhaphides One size: o-o6mm One size: 0-176— O-19'iim One size: o-i4mm Two sizes: long: 0-15— o-i7mm short: 0-042— o-o57mm Two sizes : long: o-i5mm short: 0-0481' >"» Two sizes: long: 0-15— o-i6mra short: 0-043— o-o6mm Two sizes: long: 0-25 — 0-268"'™ short: o-oS — o-imm Three sizes: longest: o-iymm and o-oo5mm middle: o-i5mm, fine short : 0-04""" and o-oo3mm Three sizes: longest: o-ii»>» fine middle: o-iosmm and o*oo3mm short: o-033mm and o*ooimm One size: o-iSmlrl Commata not observed Gemmulae? not observed not observed not observed not observed o-oi 1— 0-014" o-oo9mm and asters with stubby points : o-oo8ram o-oii — o-oi4nln' o-ooSi™ not observed not observed + not observed + not observed not observed PORIFERA. I. gg On account of the rather considerable differences with regard to the spiculation, I take the- two varieties trirhaphis and fistulosa established by Topsent (Rev. Suisse de Zool. IV, 1897, 461, PLXVIII, Fig. 9, PL XXI, Fig. 35; 462, PI. XVIII, Fig. 11), to be independent species, and this opinion may, I suppose, also hold good with regard to Fristedt's variety stellifera, the spiculation of which is quite peculiar. Kieschnick (Semon : Zool. Forschungsreisen in Austr. Band V. Denkschrift Med. Nat Gesellsch. Jena, Band 8, 1900, 568, Tab. XL V, Fig. 53— 56) establishes a Desmacella fragilis from Amboyna, whose spiculation of microsclera is given thus: grosse Doppelhaken, Sigma, zarten Bogen, Trichodragmen , but neither from the very incomplete description nor from the figures (the zarten Bogen are not figured) can anything be seen but the fact that the species belongs to the present group. I shall further call attention to the fact that the genus Sigmaxinella with the species austra- liana Dend., flabellata Cart, and ciocalyptoides Dend., established by Dendy (Proceed, of the Roy. Soaof Vict. IX, 1897, 240) and referred to .-Lr///r///,/,,\ would, according to the descriptions in hand, scarcely seem to be different from Desmacella. Topsent, in 1892, enumerates the Des7nacella-s])ecies then known to him, and mentions six; of these Peachii and aberrans are mentioned above; of the other four annexa has here been referred to the genus Biemma. The other species are: pumilio Schm., vagabunda Schm., and cavernula Bow. With regard to pumilio and vagabunda it is, on account of the shortness of the description, impossible to form any nearer opinion; with regard to vagabunda there may, perhaps, be some probability that it may be a Desmacella. Later has, besides the species mentioned above, one more species supervened, viz. the D. vulgaris, established by Topsent 1892 (Arch, de zool. exp. et gen. X, 1892, XXI|. Besides tin ten Desmacella-species belonging to one group, which are enumerated above, the genus consequently still comprises the following: Desmacella pumilio .Sclim. ? vagabunda Schm. ? cavernula Bow. vulgaris Tops. Hamacantha Gray. The form varying, massive, roundish or quite irregular, sometimes more or less erect, or fit crust-shaped; sometimes provided with papilla:. The skeleton is an irregular network of mostly p spicular fibres and irregularly sniftered spicules and bundles of spicules. Spongin is pro, a small degree, or wanting. Spicula: Megasclera ?tyli, sometimes oxea interspersed between the styli, or exclu- sively oxen. Microsclera; the microsclera characteristic of the genus, are diancistra of one to th different firms, together with which may be found toxa, trie hod ragmata. or sigmata. 1. H. Bowerbanki n. sp. PI. VII, Figs. 2 3, PI. XVIII, Fig. 1 a k, Figs 2 3. 1874. ? Halichondria falcula Bowerbank, Mon. Brit. Spong. Ill, 208, PI. LXXIV, figs, i 3. 1882. Hymcdesmia Johnsoni Carter, Ann. Mag. Nat. Hist. Ser. 5, IX, 297, PI. XI, fig. 20 a— e. 15 io2 PORIFERA. I. found, which have already been figured by O. Schmidt (Spongien des Meerbus. von Mexico 1S80, Tat. IX, Fig. 10). The earliest stage I have seen, is a quite thin needle, rather shortly recurved in both ends, and of about the .^aine length as the fully developed diancistron. The development now consists in the needle growing in thickness, the ends increasing in length, and the sharp edges being formed. All phases of this development may be found, as shown in PL XVIII, fig. i d. It has been a matter of some speculation whether these diancistra were most justly to be termed sigmata or cheke. ( ). Sell m id t (Spong. d. atlant. Gebiet. 1870, 54, and Spong. d. Meerbus. von Mexico, 1880, 82), declares them to be a modification of sigmata, on account partly of their being developed from a phase that he thinks to be sigma-like, partly of their being contort as many sigmata. Carter (Ann. Mag. Nat. Hist. 5, IX, 298), on the other hand, finds by comparing them with the peculiar, contort chela in Espcrclla (Desmacidon) titubans, that they are chela; ( auchorates ), while Yosmaer (The Spong. of Villem Barents , Bijdr. tot de Dierk., i2te Aflev., 3\\< skives no measurings of the different forms. Now it is rather certain that Topseut has had bei ') Ridley and Dendy, PI. XVII, fig. 2d, figui I thi 1 imall diancistra, and say iu the explanation of the ] oung diancistron, showing the hooks -nil united to tin- shaft bj a thin web . which 1 uowu in tl this interpretation, however, is wrong, the structure being the same as in the small di cut species; th. that the edge issuing from the shaft is very broad, and comes close to the recurved end, but it is al-n from this end. In //. , v only two forms oi diancistra are founi ponding to the smallest and I I oi thi present species. IQ4 . PORIFERA. I. him more than one species; at least the fact is that the two Haiiiacant/ia-sptci&s I have before me, the present species and the following one, are entirely constant with regard to their spicnlation; one has always three forms of diancistra and toxa, the other always only one form of diancistra, and rhaphides, but no toxa. To this constant difference in the spicnlation is further, as appears from the descriptions, added other constant characters. To judge by the forms of microsclera mentioned by Topsent, it would appear that he has had three species, viz. the present one (all the specimens with toxa), the following one (the specimen with rhaphides), and a species with sigmata. As has been shown, we do not at present know with certainty, what H.Johnsoni is, and therefore I presume it will be best by the determination to leave this species out of consideration. On the other hand there might be some possibility that Halichondria falcula Bow. is identical with the present species, but this fact cannot be decided by Bower bank's description. Thus he mentions and figures only one form of diancistra; as skeleton-spicule he figures a stylus of common form, but in the description he uses the term fusiformi-acuate . The description of the external form and the surface agrees well with the present species. Finally the species is obtained at the Shetland Islands, which localitv is not very far from several of the stations, on which H. Bowerbanki is obtained. The Rymedesmia Johnsoni mentioned by Carter 1. c, seems, by being possessed of toxa, and also by the description upon the whole, rather certainly to be identical with the present species. Locality: Station i, 620 30' Lat. N., 8 21' Long. W., depth 132 fathoms; station 9, 6zp 18' Lat. N., 27 00' Long. W., depth 295 fathoms; station 10, 64' 24' Lat. N., 2S: 50' Long. W., depth 788 fathoms; station 27, 640 54' Lat. N., 55' 10' Long. W., depth 393 fathoms; station Si, 61 44' Lat. X., 27: 00' Long. YV., depth 485 fathoms; station 85, 63° 21' Lat. N., 25' 21' Long. W., depth 170 fathoms; station 89, 64- 45' Lat. N., 27 20' Long. YV., depth 310 fathoms; station 90, 64 45' Lat. X., 29 06' Long. YV., depth 568 fa- thoms; station 94, 64" 56' Lat. X., 360 19' Long. YY\, depth 204 fathoms; station 97, 65° 28' Lat. X., 27' 39' Long. YV.. depth 450 fathoms; station 98, 650 38' Lat. X., a6: 27' Long. YYr., depth 13S fathoms; station 112, I tj 57' Lat. X., 6 44' Long. YV., depth 1267 fathoms Itemperature -=- i°i C). Finally it has been taken on 64' 42' Lat. X., 270 43' Long. YV., depth 426 fathoms (YY'audel). All these stations are between ca. 62 and 68c Lat. X., and are dispersed in the sea between the Faroe Islands and Iceland, to the south of Iceland, the Denmark Strait, and the Davis Strait. The depth ranges between 132 and 1267 fathoms. ( hi some of the stations, especially station 89, the species has been taken in very large numbers. On station 112 with the great depth of 1267 fathoms and the negative bottom temperature only a single quite small specimen was taken. On the other hand the largest specimens are from the stations 1 and 98 with depths of respectively 132 and 138 fathoms. Geogr.distr. Carter I.e. mentions his Hymedesmia Johnsoni from between Scotland and the oe [slands and from Madeira. According to what is stated above, the species must also be sup- posed to have been taken on the expedition of the Prince of Monaco 1886—88. 2. H. implicans n. sp. PI. V, Figs. 6— 9, PI. XIX, Fig. 1 a — e. Figs. 2 — 6. 1885. ? Hamacantha papillata Yosmaer, Sponges of the Villem Barents , Bijdrag. tot de Dierk., \2^ Afl. Gedeelt. 28, PI. I, fig. 15 a— b, PI. V, figs. 82— S6. PORIFERA. I. m. 1892. Hamacanthajohnsoni var. complanata, partim, specimen rhaphidibus inslructum, Topsent, Result des Campagn. scient. du Prince de Monaco, Fasc. II, 87, PI. VII, fig. 5b, h. Formed like aflat cushion, or more or /ess crust-shaped, provided with more or fewer, round or flattened, conical papilla. Embodies cxtra?ieous bodies copiously, especially 11/ the port turned towards the substratum. Outermost the sponge //as a rather firm derma/ layer provided with close-lying spicules in several layers parallel to the surface, but otherwise lying in every direction; from these layers ct standing spicules project, and therefore the surface is shaggy. Oscula are found at the summits of the papilla. The skeleton eousists of irregularly running, polyspicular fibres and scattered spicules. Spongin wanting. Spicula: Megasclera styli o-2j—o-68mm; microsclera diancistra 0/ one form o-ig—o-22mm; rlia- pliieles in trichodragmata <>■//""". This species has a quite peculiar way of growing ; it grows as thinner or thicker incrustations on shells of Mollusks, Bryozoa, worm-tubes, stones etc.; but generally it spreads over the body on which it is growing, grows round it, and embodies it completely; sometimes the substratum lias only been small stones and particles of gravel, and even if it grows on a more extended substratum, it always includes extraneous bodies copiously, so that, when a specimen is cut through, the lower half is always found abundantly filled with foreign bodies, especially pebbles and -ravel (PI. V, fig. 9). These particles are kept together and surrounded by sponge-tissue. Besides thus having incrusted foreign bodies, the sponge moreover is most frequently somewhat incrusted on the outside, and on account of its form folds and hollows may be formed, which, as it seems, may be quite closed by coalescings, and be filled with gravel and the like. Thus these cavities belong originally to the surface of the sponge, and by the cutting through of a sponge, in which they are found, cavities will accordingly be found filled with foreign particles, of which cavities some belong to the interior of the sponge, while others belong to the surface; they may, however, be distinguished from each other by the fact that the sur- face of the sponge is finely shaggy, and therefore the walls of the cavities, which do not belong to the interior of the sponge, but have their origin from coalescings, are shaggy from projecting spicules. The form of the sponge may otherwise be somewhat varying according to the substratum, on which it is growing; when growing on large, flat shells, it forms a regular crust or cushion, while it is oftenest more or less irregular, when growing on smaller bodies. The largest specimen in hand, growing on a Pecten-sheW, has a greatest extent of ca. 47"1"1 and a thickness of 6— 7mm. The other specimens grow especially on bivalves and Brachiopods, ami are most frequently growing on, or have incrusted, several shells. The surface is set with a larger or smaller number of conical formed by the skin; the papillae have an average length of 5 — 7"""; they are either round or fi Other- wise the surface is shaggy from projecting spicules. The sponge is verj cavernous, and especially in the upper part, where no extraneous bodies are embodied, large cavities are found immediate!;, under, the skin; therefore it is of a somewhat vesicular consistency. The colour (in spirit) is grayish \vl somewhat transparent, but often it appears to be brownish on account of sand and mud covering Externally the sponge is provided with a rather firm dermal layer furnished with rati se-lying spicules intercrossing in all directions, but parallel to the surface; they are lying in several and the part marked off as skin, has a thickness of ca.O'io""". Through the spicules of the skin other The [ngolf-Expedition. VI, i- IOO PORIFERA. I. spicules project rather close to each other; they are stuck with one end between the parallel spicules of the skin, while all the other part projects, so that the skin is very distinctly shaggy (PI. XIX, fig 3). Oscula and pores: In the examined specimens the pores were only found in small numbers; they are small and difficult to observe, not going vertically through the dermal layer, and so their outer opening is only little conspicuous when a piece of stained skin is viewed from above. The size is measured from o-on — o-028mm. Oscula: as before said the surface has a larger or smaller number i;ipillre, up to a score in the largest specimens. These papillse are formed by the dermal layer; the spicules of the skin are here arranged parallelly to the longitudinal axis of the papilla. On the summit of the papilla the oscular opening is found; these openings, however, are not round, but are made by the skin of the papilla being split into a number of narrow lobes, and according to this arrange- ment the spicules in the outermost part of the papilla are gathered in a like number of bands (PL XIX, Kg. 5). The papilla? may have a somewhat different appearance, which would seem to be due to a different degree of contraction. In their most extended form thev are thin-skinned and translucent, of a length of 6 — jmm, are tapering and often compressed (PI. V, figs. 7 — 8). Then they may be shorter and shorter, and at the same time they become round and more compact, and the end becomes stubby, and assumes also a darker colour (PI. V, fig. 6). They may be so short as only to form a quite flat prominence; at the same time a kind of folding must take place, for when such a papilla is viewed from above under the microscope it is seen that the very close-packed spicules form, as it were, bands or partition walls going from the middle towards the periphery (PI. XIX, fig. 6). The skeleton: As has been said above, the sponge is very cavernous, and therefore its body consists mostly of more or less membrane-like parts wdiieh in the lower part of the sponge surround and keep together an abundant mass of extraneous bodies, while in the upper part of the sponge they surround and bound a number of cavities, into which the pores lead, and from some of which oscula lead out. The skeleton therefore, besides of the mentioned dermal skeleton, consists of some irregular fibres, partly found in the membrane-like parts separating the cavities, partly running freely here and there, especially from the lower part to the dermal layer. The fibres found in the membranes are polyspicular, sometimes distinct and well defined, sometimes more dissolved in the membrane. Besides with these fibres the membrane is also provided with diancistra lying in beautiful rosettes rather close to each other (PI. XIX, fig. 4). Also the freely running fibres are polyspicular, and have rather many spicula alongside. The thickness of the fibres is generally o-io— cvi7mm. As in the pre- ceding species diancistra are found in rosettes on the fibres. In the lower part of the sponge fibres may be found where there is some interval between the incrusted extraneous bodies; where such is not the case the parts of the tissue between the foreign particles are provided with diancistra placed in rosettes in large numbers, and only a few needles. Spongin is not seen in the skeleton. Spicula: a. Megasclera are styli; they are straight or slightly curved, sometimes a somewhat sharper bend is found at the head end; they are thickest in the middle tapering somewhat to the rounded end, though not so much as in the styli of the preceding species; the smaller needles are 1st tapering, often quite imperceptibly, and sometimes not at all. The opposite end may be some- l different; most frequently it has a very stubby point that may end in a quite small, pointed in other cases the point is more long and evenly tapering. The length varies very consider- PORIFERA. I. ably, from 0-27 — o-6S'nm, the thickness is in proportion 0-005 — 0-0178"""; a few, quite fine needles, deve- lopmental forms, are seen; but besides these, part of the needles lying between the said limits, especially the comparatively long and fine ones, are presumably also developmental forms; it is, however, difficult in all instances to decide with certainty which needles are developmental forms, as the fully developed needles surely vary much in size; thus needles are found of a length of 0 ■ ■ a thickness of 0.0IImm. on account of the proportion between length and thickness these needles convey the impression of being fully developed, and when the question is of spicules of this length presumably only the finer ones are developmental forms, b. Microsclera: 1. Diancistra; in the present species diancistra are- only found of one kind; they are chiefly of the same structure as the large diancistron of the prece- ding species, but are distinguished from it by being longer and more slender, and generall) the shaft is a little bent; the recurved ends generally form a smaller angle with the shaft than in / :nki\ the edge issuing from the shaft, decreases evenly towards the middle, so that the notch between the two edges is longer and not so highly conspicuous as in the preceding species. Further these diancistra are far less contort, not rarely quite plane. The length is between 0-19 and o-22mm, most frequently it is o-2o8mm. The thickness in the middle is o-ooS — o-oio"1'". The development of the diancistra takes place in the same way as in the preceding species, as shown on PI. XIX, fig. 1 c — d. The diancistra are found in rosettes on the fibres, but this feature is not so distinctly marked as in the preceding species; further they are, as already mentioned, found in rosettes on the membranes separating the cavities, and thev are also seen in the innermost layer of the dermal layer, which is presumably lined by the same membrane, and also here in beautiful rosettes; finally the diancistra are also found abun- dantly in rosettes in the lower part of the sponge among the extraneous bodies. 2. Rhaphides; th are especially fine, the thickness is about croooj""11, and they have an average length of o-nmm; they occur in bundles, trichodragmata, containing a large number of rhaphides; they are found through the sponge, but especially on the membranes and in the innermost part of the dermal layer. Remarks: In this species cellules spheruleuses were found in large numbers in the dermal layer and the membranes; they are quite globular or fusiform, densely filled with somewhat refringent granules, and are in spirit of a light yellow colour; the size of the round ones is ca. 0X> the fusiform ones are somewhat longer. As has been mentioned under the preceding species I think that Topsent I.e. under his //. lohnsoni has comprised more than one species; the specimen of var. complanata with rhaphides, mentioned at p. 87, seems undoubtedly to belong to the presenl species. The H. papillata established by Vosmaer 1. c., seems by the occurrence of papillae and upon the whole by it-- 5 to agree with the present species, but the exceedingly incomplete ami short description ives no sufficient hold for a determination, and as the mentioned and figured spicules do no; agree with the present species, and rhaphides are not mentioned, the referring is doubtful. Locality: The present species has upon the whole been taken on the same stations preceding one, but in smaller numbers. Station 9, 64 iS' I. at. \ '., t 00' Long. W., d< thou station [0,64 24' Lat. N., 28 50' Long. W., depth 788 fathoms; statioi VV., depth 393 fathoms; station 35, 65 id' Lat. N., . Long. W., dep fathoms; station Si, 6: || io8 PORIFERA. I. Lat N., 27 00' Long. W„ depth 485 fathoms; station 85, 630 21' Lat. N, 25' 21' Long. W., depth 170 fathoms; station 89, 64°45' Lat. X., 27 20' Long. W., depth 310 fathoms; station 94, 64- 56' Lat. N., 36' 19' Long. \V., depth 204 fathoms. Thirty and odd specimens have been taken in all. According to the localities the species is spread in the Davis Strait and the Denmark Strait between ea. 62c and 650 Lat. N., on depths from 170 — 788 fathoms. Gt ^gr.distr. Where the specimen mentioned by Top sent, 1. c, which I refer to this species, has been taken cannot be stated, but the collections, as well known, were made from the Bay of Gascony over the Azores to New Fo midland, and accordingly the species reaches down to ca. 380 Lat. N. The- //. papilla fa of Yosmaer is taken south of Spitsbergen on depths of 145 and 180 fathoms. As correctly stated by Topsent I.e., the genus Vomerula established by O.Schmidt in 1880, and kept in 1887 by Ridley and Dendy in Challeng. Monaxonida together with Gray's genus Hamacantha established in 1867, will have to be comprised under this genns as a synonym, and thus Hamacantha will be the only genus in the subfamily Hamacaiitliiiicr. As certainly charac- terized as is the genus Hamacantha, as much incertaiuty is found with, regard to some of its species. Ridley and Dendy are surely right, when they (Challeng. Report, Monaxonida, LXVI) express the opinion that the H.tibicen established by O. Schmidt 1880 (Spong. der Meerbus. von Mexiko, II, 83), which is said to have as well diancistra as chelse ( Doppelankern Schmidt), is either a Desmacidonid with sigmata of such a form, that they might be misinterpreted as diancistra, or, what is perhaps more possible, with diancistra as foreign bodies. At present the list of the species belonging to Hamacantha, looks as follows: 1864. Hamacantha (Hymedesmia) Johnsoni Bow. — Doubtful; the original never described; see before under //. Bowerbanki. i-s74- (Halichondria) falcula Bow. -- Perhaps = H. Bowerbanki mihi; see this species. 1880. 1 Vomerula) Inula Schmidt. — Stated to have fine oxea ( feine Umspitzen Schm.) and bows, with transitional links between them. 1880. 1 Vomerula) tibicen Schmidt. — As stated above scarcely a Hamacantha. 1882. (Hymedesmia) Schmidtii Cart. — Stated by Carter to have oxea, diancistra and genuine sigmata1). 1885. papillata Yosm. -- Perhaps = H.implicans mihi; see this species. T's,s7' (Vomerula) esperioides R. and D. -- Well characterized species, has of microsclera sigmata and diancistra of two forms. Bowerbanki mihi. implicans mihi. ') This species (Ann. Mag. Xat. Hist. Ser. 5, IX, 297, PL n, fig. 21 a— e) might perhaps be identical with H. esperioides R. anil I)., as it appears to have diancistra of two forms and sigmata; Carter, to be sure, states it to be possessed of oxea, but his figure would imply that the question is of styli with highly tapering head ends. When Carter refers Schmidt's H. Johnsoni from Florida 1 Spong. Atl. Gebiet.) to his species, this is surelv not correct, as it does not appear from the descrip- tion of Schmidt that his species has real sigmata. Plate I. Page Fig. i. Pachychalina Schmidtii n. sp. l/i 5 — 2. Pachychalina Schmidtii n. sp. '/i — — 3. Siphonochalina pulcherrima Frstdt. J/i x3 — 4. Siphonochalina pulcherrima Frstdt. A tube cut through. I/I — 5. Halichondria velamentosa Arm. Hans. A calicular specimen; the skin wanting in some places, '/i 22 — 6. Reniera urceolus Rathke et Vahl. r/i 35 hii/oll' l:.< in ihlioii rn I7.i Luna <>■■ m '."', ') A , i ■ - I c ? i 6 1 ' * . »fr • ,» '.- k \i ' ' •'*- I {&.*"'* ^ \ r c Plate IV. Page Fig. i. Eumastia sitiens O. S. A pore papilla. A little more than 2 , 31 — 2. Eumastia sitiens O. S. An oscular papilla. A little more than 2/i — 3. Eumastia sitiens O. S. A pore- and osenlar papilla. A little more than 1'1 .... 4. Eumastia sitiens O. S. A pore papilla ent through , showing the skeleton. A little more than -.. ■', — 5. Eumastia sitiens O. S. The end of an oscular papilla, ca. In '', — 6. Eumastia sitiens O. S., attached to a Pectcn islandicus\ in a couple of the papillae is seen Aristias tumid us Kr. :/i — 7. Petrosia crassa Cart., attached to a little stone together with an Octactinia. At the lowermost part of the sponge the skin is partly wanting. */, 54 — 8. Petrosia crassa Cart. One of the most differentiated oscnla. 2 , — 9. Petrosia crassa Cart. Section of the sponge through an oscnlnm, showing espe- cially the radiating canals, and partly those parallel to the surface. r/i — - 10. Desmacella Peachii Bow. A quite young individual on a fragment of a Sipho. 5/2 9° ■ 11. Desmacella Peachii Bow. A somewhat older individual on a fragment of a Sipho. 3/2 — — 12. Desmacella Peachii Bow. ljs — - 13. Desmacella Peachii Bow. A calicular specimen, the skin is wanting, and the edge is damaged. I/1 — — 14. Biemma auuexa O. S. a the place of attachment. '/, 85 to 1, $£ -'XV /.', i i S| .-» // Plate V. Page Fig. i. Reniera calamus n. sp. Fragment. ' ■', 4cS 2. Reniera calamus n. sp. Cut through. tj1 3. Gelliodes plcxa n. sp. A leaf-shaped piece viewed from the inside, the skin is only kept in the middle. ' , 75 - 4. Gelliodes plexa n. sp. A funnel-shaped specimen, the greater part of the upper edge broken off; the skin wanting on the outside. t/1 — — 5. Reniera folium n. sp. l/t 39 6. Hamacautha implicans n. sp. Most of the papilla? highly contracted. ' , 104 7. Hamacautha implicans n. sp. The papillae stretched out. l/s — 8. Hamacautha implicans u. sp. The papilla; stretched out. '/, — — 9. Hamacautha implicans n. sp. Cut through to show the extraneous bodies em- bodied in the lower part, and the cavities of the upper part. 2/, — .'/ I'/./ * •' \ ' \ ■ '• »'/• ,^y: :■■■■>■■, ., i«v •*■.-.. • -Mi'//-. ♦ ' / . $ - 4r 1&1&W&. > * a;v . • «g*g Ife-V - t * '■:•'■ -3 '■■«."» / » . - - Plate VI. Page Fig. i. Biemma rosea Frstdt. The largest piece seen from the pore side; the skin wan- ting in a few places. I/1 82 — 2. Biemma rosea Frstdt. A piece probably from the middle of the sponge, seen from the oscular side. ' ^ — — 3. Phl&odictyon elongatum Tops. 1jl 59 — 4. Plilceodictyou elo>igatum Tops., highly incrusted with sand. I/l — — 5. Gellius litridus n. sp. Somewhat damaged above, but less than the two follo- wing ones. ' , 64 — 6. Gellius litridus n. sp. Broken off above. l 1 — — 7. Gellius litridus n. sp. Broken off above. '/, — — 8. Gellius litridus n. sp. The preceding specimen (fig. 7) cut through longitudinally. 1 1 — 9. Pklceodictyon irregulare 11. sp. I/s 61 — 10. Pklceodictyon irregulare n. sp. 1'1 — — n. Phl&odictyon tuber n. sp. liI 57 — 12. Pklaiodictyon tuber n. sp., incrusted with sand. l l — — 13. Phlazodictyou tuber n. sp., showing a broken off fistula, '/i — — 14. Desmacella groenlaudica Frstdt. Skin with oscula closed in different degrees. Ends of fibres are seen. ca. 20 T 95 Inqolf <£^S3 10 ■ . » * v*. : .-. '•>.•' •;i' ft * • * - :> /* * . . . 1 > . '■'* ■ 1 * by ■•'■" '•••:•.': •'■•■ »•.••• ,.• - •••.•>.-•. ...1 >•.>:•/•; -.-•••.• ••..•■•.•.•••••■? ■■;•:•■■.:-« • . _ > a V -_—. rt • • • ^* -O - • ■ * *i • - ' 0- - , // feijP Plate VII. Page Fig. i. Reniera parenchyma n. sp. '/i 37 2. Hamacantka Bowerbanki n. sp., showing one osculum; the surface damaged in places. '/, 99 — 3. Hamacantka Bowerbanki n. sp., showing several oscula. I/J — 4. Desmacella hamifera n. sp. A leaf-shaped fragment, the skin almost quite want- ing- 7i • • • 93 5. Desmacella hamifera n. sp. The middle part of a short-stalked, calicular specimen. v. - ■ 6. Desmacella hamifera 11. sp. Radial longitudinal section through the wall, showing the skeleton. s/2 — /• Desmacella groenlaudica Frstdt. The skin wanting on the outside. 1/I 95 ///t/i>// ExptdiUonert 17 / I. mi,. ' H I <, m4$ V ■ Plate VIII. Page Fig. i. Pachychalina Schmidtii n. sp. Oxea, a fully developed, b developmental forms, x 255 5 — 2. Pachychalina Schmidtii n. sp. Longitudinal section of the skeleton towards the surface, but not reaching it, x ca. 20. a inward, b outward — — 3. Pachychalina Schmidtii u. sp. A piece of the skeleton, x 60 — 4. Pachychalina caulifera Yosm. Oxea, a fully developed, b developmental forms, x 255 7 5. Pachychalina caulifera Yosm. Longitudinal section of the skeleton towards the surface, x ca. 20. a inward, b outward — — 6. Pachychalina caulifera Yosm. A piece of the skeleton, x ca. 100; as it is near the surface the longitudinal fibres are running almost horizontally — — 7. Chalina oat lata Pall. Oxea. x 255 10 8. Chalina spatula u. sp. Oxea, a fully developed, b developmental forms, x 255 . n 9. Chalina spatula n. sp. Section of the skeleton at the edge, x ca. 14. A few of the polyspicular fibres are seen — ■ in. Siphonochalina pulcherrima Frstdt. Oxea, a fully developed, b developmental f. irms, x 255 13 - 11. Siphonochalina pulcherrima Frstdt. Longitudinal section of the skeleton from the surface some way inward, x ca. 20. A few polyspicular fibres are seen. a inward, b outward — ■ 12. Siphonochalina mollicula n. sp. Oxea, a fully developed, b developmental form, x 255 15 - 13. Siphonochalina mollicula n. sp. Longitudinal section of the skeleton from the surface some way inward, x ea. 20. a inward, b outward — .— 14. Siphonochalina mot lie it la n. sp. Piece of the skeleton, x ca. 100 — Plate IX. Page Fig. i. Halichoiidria fianicea Pall. Oxea, x 165 17 2. Halichoiidria genitrix O. S. Oxea, a of the larger ones, b of the smaller ones, c lm msti cms forms, x 165 18 3. Halichoiidria fibrosa Frstdt. Oxea, a of the larger ones, b of the smaller ones, c oxeum with a swelling in the middle, x 165 20 — 4. Halichoiidria velamentosa Arm. Hans. Oxea, x 165 22 — 5. Halichoiidria velamentosa Arm. Hans. Dermal membrane from the oscular side, with a few pores, x 54 — — 6. Halichoiidria velamentosa Arm. Hans. Dermal membrane from the pore side, x 54 7. Halichoiidria oscii/iuii n. sp. Oxea, x 165 23 — 8. Halichoiidria osciiliini 11. sp. Dermal membrane, x 38 — 9. Halichoiidria oscitlitm n. sp. Membrane from the oscular cavity, x 33 — - 10. Halichoiidria oblouga Arm. Hans. Oxea, x 165 24 Plate X. Page Fig. i. Halichondria tenuiderma n. sp. Oxea, a fully developed, b developmental form, x 165 26 2. Halichondria tenuiderma n. sp. Section vertical on the surface, showing the skeleton, x 32 — — 3. Halichondria colossea n. sp. Oxea of different sizes, x 58 27 4. Halichondria colossea n. sp. Dermal membrane with a few incrusted foreign bodies, x 58 — — 5. Halichondria colossea n. sp. Canal membrane, x 58 — 6 Halichondria colossea n. sp. Section vertical on the surface, from a spot where no projecting spicules are found; a the dermal layer of small spicules — 7. Halichondria colossea n. sp. Section vertical on the surface, from a spot where projecting spicules are found; a the dermal layer of small spicules — 8. Halichondria} d if lie His n. sp. Oxea of different sizes, a oxeum with a swelling in the middle, x 165 28 — 9. Eumastia siliens O. S. Oxea, a fully developed of different sizes, b developmen- tal forms, x 165 31 — 10. Eumastia siliens O. S. Transverse section of an oscular papilla, a oscular canal, b subdermal cavities, c the fibre lying in the partition wall, x ca. 12 — - n. Eumastia siliens O. S. Transverse section of a pore papilla, in the middle the fibre with radiating branches, x ca. 12 — — 12. Eumastia siliens < ). S. Wall of pore papilla, x 58 — 'itioni'ii I'll 1 1 Plate XL Page i. Reniera urceolus Ratlike et Vahl. Oxea, x 255 35 — 2. Reniera parenchyma 11. sp. Oxea, x 255 37 3. Reniera parenchyma n. sp. Section through the middle of the skeleton of the sponge, parallel to the surface, showing oscular canals and polyspicular longi- tudinal fibres, x ca. 20 — 4. Reniera parenchyma 11. sp. Section of the skeleton vertical on the surface, x ca. 20 — — 5. Reniera folium 11. sp. Oxea, x 255 39 6. Reniera ventilabrum Frstdt. Oxea, x 255 40 7. Reniera ventilabrum, Frstdt. Skeleton seen from the surface, showing an oscu- lum and the spicules projecting from the edge of it, x ca. 54 — — 8. Reniera hyalina 11. sp. ( )xea, x 255 42 9. Reniera clavata Levins.? Oxea, x 255 43 - 10. Reniera cinerea Grant. Oxea, x 255 43 — 11. Reniera tubulosa Frstdt. Oxea, a fully developed of different sizes, b develop- mental forms, x 255 44 -lie. Reniera tubulosa Frstdt. The ends of different oxea. x 485 — - 12 - 14 - l5 - 16 , — 1 Reniera tubulosa Frstdt. Section of the skeleton vertical on the surface, x ca. 60 — Reniera laxa 11. sp. ( )xea, x 255 46 Reniera heterofibrosa 11. sp. Uxea, x 255 47 Reniera calamus n. sp. Oxea, a of the large ones, b of the small ones, x 255.. 48 Reniera calamus n. sp. Radial longitudinal section of the skeleton, x ca. 60 . . . — Reniera sp. a. ( >xeum, x 255 49 Ini/olf /'■ ■'/ ' I II 10 /• 12 i:>" n Hi Plate XII. Page Fig. i. Reniera sp. b. Oxeum, x 255 50 2. Reniera sp. c. Oxea, x 255 50 3. Reniera Voeringii Ldbk. Oxea, x 255 50 4. Metschnikowia spinispiculum Cart. Spined strongyla, a fully developed, b an older and a younger developmental form, x 255 52 5. Petrosia crassa Cart. Oxea, a of the larger ones, b of the smaller ones, c short oxea, strongyla and styli, x 255 54 6. Phhvodictyon tuber 11. sp. Oxea, a fully developed, b developmental forms, x 255 57 7. Phl&odictyon tuber n. sp. Section of the skeleton vertical on the surface, showing lamellae, a the outer surface, x ca. 32 — 8. Phhvodictyon elongatum Tops. Oxea, a fully developed, b developmental forms, x 255. c end of oxeum, x 485 59 q. Phhvodictyon elongatum Tops. The dermal layer, seen from the outside, a pro- jecting spiculum is seen, x ca. 100 — - 10. Phhvodictyon irregulare n. sp. Oxea, (7 fully developed, b developmental forms, x 255 61 11. Gellius arcoferus Vosm. a oxea, x 165, b toxa, fully developed and younger forms, x 380, c sigmata, x 485 62 - 12. Gellius angii hit us Bow.? a oxea, x 165, b ends of different oxea, x 485, c toxa of different sizes, x 485, d sigmata, x 485 63 Plate XIII. Page Fig. i. Gellius luridus n. sp. a oxea, x 165, b toxa of different sizes, x 5S5, c sigmata of different sizes, x 585 64 2. Gelliits luridus n. sp. Longitudinal section, showing the dermal layer, lamellce and canals, x ca. 2. (After a dried preparation, which makes the skeleton appear distinctly) — 3. Gellius luridus n. sp. Longitudinal section through the dermal layer in a place where this layer is thick, x ca. 33. a the part marked off as special dermal layer — 4. Gellius luridus n. sp. Dermal membrane with spicules and pores, x 65 — 5. Gellius luridus n. sp. Piece of skeleton lamella with the holes formed by the passage of the canals, x 2 — — 6. Gellius luridus n. sp. The upper part of fig. 5, x 18 — — 7. Gellius luridus n. sp. Spicules from the dermal membrane, showing the cementing by spongin, x no — — 8. Gellius luridus u. sp. Two single spicules with spongin coats, x no — — 9. Gellius microtoxa n. sp. a oxea, b developmental forms, x 165, c toxa of diffe- rent sizes, x 585, d sigmata of different sizes, e developmental forms, x 585. 67 - 10. Gellius microtoxa n. sp. Dermal membrane with spicules and cellules spheru- leuses , partly scattered, partly forming a baud, x ca. 65 — 11. Gellius primitivus n. sp. a oxea of different sizes, x 255, b toxa of different sizes, x 485 69 — 12. Gellius proximus n. sp. a oxea of different sizes, x 255, b toxa of different sizes, x 485 70 Plate XIV. Page Fig. i. Gcllius ftagellifer R. and D. a oxea, b developmental form, x 165, c flagellate sigmata, d common sigmata, x 485 71 2. Gellius porosus Frstdt. a oxea, x 165, b flagellate sigmata, c one of the thick sigmata, only occurring in small numbers, x 485 73 - 3. Gelliodes pi ex a n. sp. a oxea, b developmental form, x 165, c toxa of diffe- rent sizes and stages of development, x 380, d sigmata, x 485 75 4. Gelliodes plexa n. sp. Dermal membrane from the oscular side; the subjacent skeleton and projecting spicules are seen, x ca. 18 5. Gelliodes plexa n. sp. Dermal membrane from the pore side, x ca. 18 — 6. Gelliodes cousimilis n. sp. a oxea, b developmental form, x 165, c toxa, d a developmental form, x 380, e sigmata, x 485 77 ii , 17./. Plate XV. Page Fig. i. Oceanapia robusta Bow. a oxea, b a developmental form, x 255, c sigmata, x 700 78 2. Oceanapia robusta Bow. Radial section of the outermost part of the rind, x ea. 22; a the outermost layer with the projecting spicules — 3. Oceanapia robusta Bow. Piece of the membrane surrounding the canals, with its skeleton, x ca. 60 — ■ 4. Oceanapia robusta Bow. The membrane lining the canals inmostly, with its spicules and cellules spheruleuses , x ca. 60. (A piece from one of the larger canals.) — ■ 5. Biciinna rosea Frstdt a subtvlostyli, b a developmental form, x 120, c head ends of different subtvlostyli, x 380, d sigmata, more or less contort, x 485. . . 82 - 6. Biemma rosea Frstdt. Dermal membrane from the pore side with projecting spicula-bundles, x ca. 32 — 7. Biemma rosea Frstdt. The surface seen from the oscular side with more or less open oscula and projecting spicula-bundles, x ca. 32 — 8. Biemma rosea Frstdt. Piece of the transverse section from the pore side to about the middle, showing the columns supporting the skin, subdermal cavities, and two large canals; the smaller canals are not given, x ca. 32 — 9. Biemma rosea Frstdt. Piece of a transverse section towards the oscular side. x ca. 32 — ' Plate XVI. Page Fig. i. Desmacella capillifera Levins, a styli of common form, b styli of the smaller form, straight with a more sharp curve at the head end, c irregular styli from the basal layer, x 77, d sigmata of the large form, e sigmata of the small form, x 485, f rhaphides, single and as trichodragmata, x 255, g com- mata, x 700 88 2. Desmacella Peachii Bow. a styli, b developmental forms, c irregular styli from the basal layer, x 77, d sigmata of the large form, e sigmadragma, f devel- opmental form of the large sigma, g sigmata of the small form, x 485, h rhaphides of the long form, single and as trichodragmata, i rhaphides of the short form, single and as trichodragmata, x 380, k commata, x 700, / silicious globules, x 485 90 hit/off Expedilioiien I'll. I1' /' Plate XVII. Page Fig. i. Desmacclla hamifera n. sp. a styli, b developmental forms, c irregular styli from the basal layer, x 77, d sigmata of the large form, e sigmadrama, f develop- mental form of the large sigma, g sigmata of the small form, x 485, h rha- phides of the long form, single and as triehodragma, / rhaphides of the short form, single and as trichodragmata, x 380, It commata, x 700, I gemmula?, x 255, silicious globules, x 485 93 2. Destnacella groenlandica Frstdt. a styli, b irregular styli from the basal layer, x 77, c sigmata of the large form, x 485, d sigmata of the small form, x 700, e rhaphides of the long form, single and as triehodragma, f rhaphides of the short form, single and as triehodragma, x 255, g commata, x 700, h gemmula?, x 255, silicious globules, x 485 (gemmula is drawn from the original specimen of Fristedt) 95 3. Biemma annexa O. S. a tylostyli and snbtylostyli , b a developmental form, x 120, c head ends of different needles, x 380, d toxa, x 485, e sigmata of the larger form, f sigmata of the smaller form, x 485 85 //./. / Plate XVIII. Page Fig. i. Hamacantha Boiuerbauki n. sp. a styli, £ developmental forms, x 165, c diancistra of the largest form, d a series of developmental forms, x 380, e diancistra of the middle form, f a developmental form, x 700, g the same diancistron, x 380 (br this enlargement the edges are not seen), h diancistra of the smallest form, x 700, i the same diancistron, x 380, the edges are not seen, k toxa, x 380. 99 2. Hamacantha Bowerbanki n. sp. Dermal membrane with skeleton and projecting spicules, x 58 — 3. Hamacantha Bowerbanki n. sp. Radial section of the skeleton from the surface inward, x 32. a the skin with spicules . Plate XIX. Page Fig. i. Hamacantha implicans n. sp. a styli of different sizes, b developmental forms, x 165, c diancistra, d two developmental forms, x 380, e rhaphides, single and as trichodragma, x 380 104 2. Hamacantha implicans n. sp. Dermal membrane with skeleton, x 58 3. Hamacantha implicans n. sp. Transverse section of skin with projecting spicules, — x ca. 54 — 4. Hamacantha implicans 11. sp. Piece of a membrane with fibres and diancistra in rosettes, x 32 — — 5. Hamacantha implicans n. sp. An oscular cone stretched out, x ca. 20 — — 6. Hamacantha implicans n. sp. An oscular cone contracted, seen from above, showing the vertical spicides arranged in a bandlike manner, x ca. 20 — o THE INGOLF-EXPEDITION 1895— 1896. THE LOCALITIES, DEPTHS, AND BOTTOMTEMPERATURES OF THE STATIONS. Station Nr. Lat. N. i 2 3 4 5 6 7 S 9 io 1 1 12 '3 14 15 16 '7 I S '9 2<> 21 22 23 620 30' 63° 04' 63° 35' 64° 07' 640 40' 63° 43' &3° 13' 63° 56' 640 iS' 64° 24' 64° 34' 64° 38' 64° 47' 64° 45' 66° 18' 65° 43' 62° 49' 6," 44' 6o< 58' 58' 58' 60° 43' 29 20' 01' 10' Loii". W. Depth in Danish fathoms 8°2I' 90 22' io° 24' 11° 12' 12° 09' 14° 34' 15° 41' 240 40' 27° 00' 280 50' 31° 12' 32° 37' 34° 33' 35° 05' 25° 59' 26° 58' 260 55' 30° 29' 34° 'I' 40° 48' 44° 45' 48° 25' 56° I K I Bottom- temp. 132 262 272 237 155 90 600 136 295 7SS 1300 [<>)<> 622 176 330 250 745 1 1 35 ,566 1695 1330 t845 Onlj the Plankton Nel I 7°2 5°3 o°5 2°5 7°o 4°5 6°o 5°S 3°5 i°6 o°3 3°° 4°4 -o°75 6° 1 3°4 3°' ' 2°4 i°5 I I [°4 Station Nr. 24 25 26 27 28 29 3° 3' 32 33 34 35 36 37 38 39 40 41 I-' 43 Lat. N. Long. W, Depth in Danish fathoms 63° 06- 56° 00' 63° 3°' 54° 25' 63° 5i' 53° 03' 63° 57' 52° 41' 64° 37' 54° 24' 64° 54' 55° lo- 65° 14 SS0 42' 65° 34' 54° 31' 66° 50' 54° 2S- 66° 35' 55° 54' 66° 35' 56° 38' 67° 57' 55° 3°' 650 "7' 54° 17' 65° 16' 15 05 61 ° 50' 56° 21' 6o° 1 7' 54°" 59° t2' 5i° °5' 62° <><>' 22° 38' 62" 01 >' 21° 3"' 61 " . 17° [1 1 61 ' 41' to0 17' 61 1 ■ 111 1 [' 6i° i' 9 ,6 1 199 582 136 34 109 393 420 6S 22 ss 318 35 55 362 1 435 1 7 ' 5> [870 865 845 1245 645 545 Bottom- temp. 2 "4 3°3 o°6 3°5 0°2 t°05 1 6 o 8 >°5 t°4 i°3 2°9 3 3 1 ! Station Nr. Lat. X. Long.W. Deptli in Bottom- Danish temp, fathoms 45 46 47 48 49 50 5' 52 53 54 55 56 57 58 59 60 61 62 63 64 65 "7 61° 32' 9° 43' 61° 32' 11° 36' 61° 32' 13° 4"' 61° 32' 15° 11' 62° 07' 15° 07 62 43' 15° "7' 64° 15' 1 4 -'-' 63° 57' 13° 32' 63° 15' 15° "7' 63 15° 41 15 64 -. 16' 30' 643 720 95a 1150 I 121) I020 68 795 691 316 350 21 1 310 124 55 112S 4-17 3°23 3°i/ 2°9I 3° '3 Station Xr. Long. W. Lat N. ])q>th in Danish fathoms Bottom- temp. Station Nr. Lat. N. Long. W. Depth in Danish fathoms Bottom- temp. Station Nr. Lat. N. Long. W. Depth in Danish fathoms Bottom- temp. 68 620 06' 22° 30' 843 3°4 92 64° 44' 32° 52' 976 i°4 118 68° 27' S°20' 1060 — i°o 69 62° 40' 22° 17' 589 3°9 93 64° 24' 35° 14' 767 i°46 119 67° 53' 10° 19' IOIO — i°o 70 63° 09' 22° 05' 134 7°° 94 64° 56' 36° 19' 204 4°i 120 67° 29' i'° 32' 885 — i°o 71 63° 46' 22° 03' 46 65°3i' 3o° 45' 213 121 66° 59' 13° 11' 529 — o°7 72 630 12' 23° 04' '97 6°7 95 65° 14' 3o° 39 752 2°l 122 66° 42' 14° 44' "5 i°S 73 620 58' 23° 28' 4S6 5°5 96 650 24' 29° 00' 735 I°2 123 66° 52' '5° 4o' 145 2°o 74 620 17' 24° 36' 695 4°2 97 65° 28' 27° 39 450 5°5 124 67° 40' '5° 40' 495 — o°6 61° 57' 25° 35' 761 98 65° 38' 26° 27' 138 5°9 125 68° 08' 1 6° 02' 729 — o°8 61° 28' 25° 06' 829 99 66° 13 25° 53' 1S7 6°i 126 67° 19 '5° 52' 293 -o°5 75 6i°28' 26° 25' 780 4°3 100 66° 23' 14° 02' 59 o°4 127 66° 33' 20° 05' 44 5°6 76 60° 50' 26° 50' S06 4° 1 IOI 66° 23' 12° 05' 537 -o°7 12S 66° 50' 20° 02' '94 o°6 77 60° 10' 26° 59 95' 3°6 102 66° 23' io° 26' 75o -o°9 129 66° 35' 23° 47' "7 6°5 7S 60° 37' 27° 52' 799 4°5 i°3 66° 23' 8° 52' 579 — o°6 130 63° 00' 20° 40' 33S 6°55 79 6o° 52' 28° 58' 653 4°4 104 66° 23- 7°25' 957 — I°I 131 63° 00' 19° 09' 69S 4°7 80 61° 02' 29° 32' 935 4°o 105 65° 34' 7° 31' 762 — o°8 132 63° 00' 17° 04- 747 4°6 Si 61° 44' 27° 00' 4S5 6°i 106 65° 34' 8° 54' 447 — o°6 133 63° '4' 11° 24' 230 2°2 82 6i° 55' 27° 28' 824 4°i 65° 29' 8° 40' 466 134 62° 34' 10° 26' 299 4°l S3 62° 25' 28° 30' 912 3°5 107 65° 33' io° 2S' 492 -o°3 '35 62° 48' 9° 48' 270 o°4 62° 36' 26° 01' 472 108 65° 30' 12° 00' 97 i°i 136 63° 01' 9° 11' 256 4°8 620 36' 250 30' 401 109 65° 29 '3° 25' 38 i°5 '37 63° '4' 8° 3'' 297 — o°6 84 62° 58' 25° 24' 633 4°8 1 10 66° 44' "°33' 781 — o°8 13S 63° 26' 7°56' 47i — o°6 85 63° 21' 25° 21' 170 1 11 67° 14' 8° 48' 860 — o°9 '39 63° 36' 7° 30' 702 — o°6 S6 65 ° 03-6 23° 47*6 76 1 12 67° 57' 6° 44' 1267 — i°r 140 63° 29' 6° 57' 780 -o°9 87 65° 02' 3 23° 56' 2 no "3 69° 3i' 7°o6' 1309 — i°o 141 63° 22' 6° 58' 679 -o°6 88 64° 58' 240 25' 76 6°9 114 70° 36' 7° 29' 773 — i°o 142 63° 07' 7° 05' 5S7 — o°6 89 64° 45' 27° 20' 310 S°4 115 70° 50' 8° 29' S6 o°i '43 62° 5s- 7° 09' 388 -o°4 90 64° 45' 29° 06' 568 4°4 116 70° 05' 8° 26' 37i -o°4 '44 62° 49' 7° 12' 276 i°6 91 64° 44' 31° 00' 1236 3°> 117 &9° LV 8°23' 1003 — i°o ->-o-**>•:« 4 COPENHAGEN. PRINTED BY BIANCO LUNO. 1910. Ready from the Press Avril the ist 1910. CONTENTS. Desmacidonidte Page Desmacidonids Mycalinse Myxilleae Tedania — suctoria O.Schmidt Histoderma . < appendiculatum Cart. . . . 7 physa O. Schmidt. 11 Histodermella 13 Ingolfi n. sp 14 — coriacea n. sp 16 Inflatella 18 — pellicula O. Schmidt , . . iS. — viridis Tops .20. Cornulum 22 textile Cart .22 Grayella 24 — pyrula Cart. 30. — gelida n. sp 34, — carnosa Tops. 36. Ectyoninae 39. Hymedesmia 39. Koehleri Tops 42 lacera n. sp 44 — storea n. sp 45 lamina n. sp 46. — mollis n. sp 47 curvichela n. sp 4 s rugosa n. sp 50. splenium n. sp 51 tenuicula n. sp 52 similis n. sp 53 nummulus n. sp 55 dubia n. sp 56 stylata n. sp 57 verrucosa n. sp. 58 — procumbens u. sp. . 60. perforata u. sp 61 — clavigera n. sp. . 62 platychela n. sp 63 basispinosa n. sp 64 Page Hymedesmia longistylus 11. sp. . . 66. — occulta Bow. 67. simillima n. sp 69. baculifera Tops. 71. levis n. sp. ... 73. — bractea n. sp. 74. lsevistylus n. sp 74. Bowerbanki n. sp. ...... 75. — truncata n. sp — latrunculioides n. sp. . . . 78. — irregularis 11. sp 80. — proxima n. sp crux O. Schmidt 83. — aenigma n. sp 84. filifera O. Schmidt . S6. — grandis n. sp. 88. — digitata n. sp 90. trichoma n. sp. 91. — macrosigma n. sp. . 92. pugio n. sp 94. consanguinea u. sp. . 95. planca n. sp 96. cultrisigma n. sp. . 97. — mucronata Tops. 9S. — tenuisigma n. sp. . 100. Dujardinii Bow 101. primitiva n. sp. . . 104. longurius n. sp 105. aequata n. sp. ...... 106. — dermata n. sp toruotata 11. sp 109. — mucronella n. sp Table of the species of Hymedesmia 112. Hymeiiancora . . . 1 16. — interjecta n. sp. . . 117. — conjungens 11. sp. duplicata n. sp. 119. tenuisclera 11. sp. ■ i- ' Leptolabis . ,2-- — assimilis 11. sp. '--• Porifera. III. By William Lundbeck. (Fam. III. Desmacidonidae.) (Subfara. i. Mycalinae.) (Group 2. Myxilleae.) Tedania Gray. Of various shape, incrusting, massive, erect ami leaf- or cup-shaped, or cylindrical, or finally more or less digitate and branched. The skeleton a more or less diffuse reticulation, generally multi- spicular, more rarely partly or quite unispicular. Spongin generally (or always) present, as a rule to a sl/ght degree, sometimes more richly. The dermal skeleton as a rule formed of erect bundles of dermal spicules, sometimes also spicules lying horizontally in the dermis; it is sometimes strongly devel- oped, sometimes weaker, with relatively few spicules. Oscula scattered, sometimes on the apex of tubes or papilla; pores scattered or on the apex of papilla or otherwise definitely localized. Spicula: m sclera: I lie skeletal spicules are smooth sfy/i. the dermal spicules diactinal, fylo/a. tornota or strongyla, sometimes with slightly spined ends; microsclera only one form, rhaphides with unequal ends, finely spinulous. in dragmata or scattered. i. T. suctoria O. Schmidt. PL I, Figs. 1-5, PL IV, Fig. i. 1870. Tedania suctoria O. Schmidt, Grundziige einer Spongienf. des atlant. Gebiet. (.3, Tab. V, Fig. 11. 1875. Tedania increscens O. Schmidt, Jahresb. d. Comm. zur wiss. Unters. deutsch. Meere in Kiel fur 1872-73. "5- 1882. Tedania suctoria. Vosmaer, Niederl. Arch. f. Zool. Suppl. Hand I, 42, PL I. fig. 24, PL III, figs. 83 1885. — . Vosmaer, Bijdr. tot. de Dierk. 12" All. 3'1"' Gedeelt. 22. 1892. Tedania conuligera Topsent, Resultats des camp. sc. du Prince tic Monaco, Fasc. II. 70, PI. I. tic. 1903. Tedania increscens, Thiele, Arch, fur Naturgesch. [903, I, ,vs". Taf. XXI, Fig. 9. 1904. Tedania suctoria. Topsent, 1. c. Fasc. XXV, 176. 1909. — — , L,undbeck, Meddel. om Gronlaud, XXIX, 443. Incrusting, massive, or more creel and some/i/ues somewhat branched. Surface more or richly beset with papilla and diffusely hispid. The dermal membrane somewhat so/id. its skeleton we developed, consisting of bundles oj dermal spicules, partly creel, partly more horizontal: also scattered The Ingolf-Expedition. VI. \ PORIFERA. III. spicules. Oscula few, lying on special papilla, pores on the summit of other papilla. The skeleton a mainly polys ficular , diffuse and irregular reticulation. Spicula: megasclera: the skeletal spicules styli o-jo — o-68""", the dermal spicules tylota 0-25— 0-47""" ; microsclera one form, finely spinulous rhaphides ■with unequal ends 0-053— 0-50""". Of this species we have a very rich material from the whole Ingolf territory. The individuals may have a very different aspect, but as a rule they are characterized by having a greater or smaller number of wart-shaped papillae. In the typical and fully developed shape the species is massive, more or less roundish, lumpy and in greater or smaller extent attached to a substratum. From this roundish shape the species may show many variations, it may be elongated and assume a somewhat erect shape, and it may be club-shaped, lobate, compressed or more or less branched. The latter shape is no doubt due however, at all events partly, to the fact, that it incrusts, or originally has incrusted, branched Hydroids or Algae, but in this case it seems to be able to continue its growth out in free, branched forms. The smallest and youngest specimens are iucrusting and from this crust-shaped origin it may then bv and by grow up to the massive shape, but it may also persevere as a crust and as such reach a considerable extent. In our material it is found growing on stones, various Bryozoa, worm- tubes, Algae e. g. Ptilota plumosa, the specimen on this is branched, and finally on a crab. The largest specimen, which is of an elongated shape, has a length of about 40 mm; a massive, tuberous specimen is 30mm iu diameter; the iucrusting specimens are generally small, but may, as said, reach a greater extent, up to 25™'" with a thickness not much over rmm. Topsent mentions and figures (1. c.) larger specimens, up to an extent of 9C"K, of typical massive shape. The colour (in spirit) is yellow or whitish yellow. The consistency is of medium firmness and somewhat elastic. The surface is more or less densely beset with papillae, otherwise it is, when examined with a lens, somewhat diffusely hispid. In the larger, massive specimens the papillae are generally present in great numbers, and the same is the case with the larger crusts; in the small incrustations the papilla; may be few or indistinct. The dermal membrane is a very solid and easily separable membrane; outermost it shows a thin, film- like layer, which under the microscope is seen to be curled or folded. It would seem that this layer in the living sponge is adhesive, as it generally shows adherent foreign particles such as diatoms in great multitude. Oscula and pores: as mentioned the surface is more or less richly beset with papillae which are specially well developed in the larger specimens, while they are less developed in the small specimens. The papillae are conical in their lower part, the upper part being cylindrical. They are seen from quite small warts up to a length of 4'nm; they are compressed and have a breadth up to I'.V1""- 'These papillae must be supposed to he partly oscular- and partly pore-papillae, the fact is, that they show some difference. Some few of them are simply hollow and show an opening in the summit, their wall is thin and supported by dermal spicules which are more or less distinctly arranged as longitudinal bands; these papilla; must accordingly be taken to be oscular-papillae. By far the most of the papillae have another structure; they are hollow like the oscular-papillae, but from the wall spi- cula fibres stretch into the lumen; these fibres may be branched upwards and terminate in the upper surface of the papillae, which is thus supported by a number of spicular pillars. All the spicules in these fibres are dermal spicules. The papillae show no opening at the summit. These papillae must apposed to be pore-papillae, and probably the pores are found at their ends. The pores I have PORIFERA. III. not seen, but as the papilla; are nearly always somewhat contracted, it was also not to be expected, that the pores should be visible. The two kinds of papillae are often recognisable already from their outer shape, the oscular papilla; being somewhat evenly conicallj pointed, while the pore-papillae are- more cylindrical in their outer part and have a stubby or cut end. Often, however, the papillae are so strongly contracted, that it is not possible to distinguish them from each other so directly. In the dermal membrane outside the papillae no pores were found. The structure mentioned of the papillae has not been described hitherto, only Schmidt has some remarks about it, but he takes them all to he oscula. For the rest he speaks about the peculiarity of the dermal membrane, remarking that it consists of: "einer ausseren sarcodeartigen und einer inneren festen membranosen Schicht". From his description of the papillce it is seen, that it is a pore-papilla he has examined, which are also by far the most numerous; the fact is that he says: "Das Ende der Warzchen ist etwas verdickt, der Gipfel scheinbar geschlosseu, alleiu eine massige Vergrosserung zeigt, dass der Hauptcanal in eiuer Auzahl Haarcanalcheu sich nach aussen offnet". The "Haarcanalchen" Schmidt has seen no doubt the inner cavity divided by the fibres, and his description is otherwise in the main com only he takes the papilla to be an oscular-papilla. The skeleton. The dermal skeleton; the skeleton formed by the dermal spicule.- is not much developed, it consists of larger or smaller bundles of dermal spicules lying in the membrane, partly horizontally, partly more or less erect in the somewhat thick dermis; besides the bundles more scattered and single spicules may also occur, but they are on the whole scarce, and large parts of the membrane may be seen without dermal spicules. At the base of the papillae they are present in greater numbers, and from here they stretch out in the wall of the papilla and form the skeleton of the papilla as mentioned above. The main skeleton is a rather diffuse and irregular, multispicular reticulation in which primary and secondarv fibres cannot be discerned; also single spicules are in many places seen to contribute to the skeleton. In the points of union is seen a distinct and rutin i rich amount of spongin which may also sometimes be seen to continue along the fibres. Spiaila: a. Megasclera. i. The skeletal spicules are styli, they have an even, generally slight curve, lying nearest to the rounded end. The apex may be somewhat different, partly in the same individual, but especially in different individuals; it is generally of moderate length, but it may be both shorter and longer, and it may be bounded by straight or curved lines; finally it ma\ marked off in different ways; in a single specimen the point is often rounded and thus stubby. The length of the styles may vary considerably, yet generally not much in the single individuals, but on the other hand in different individuals; in all it is in the Species between 0-30 am . but only when the sizes measured for all individuals are taken into consideration; as the common lengths ma\ be given 0-42— o-53mm. The diameter is on the whole 0*007 min— 0-014 mm, but -iere a,s" some difference i present, in single specimens not reaching beyond o-on o-oi2,mn. _•• The dermal spicules are tyl< they are generally straight, sometimes slightly curved. They have a distinct, but often rutin ted swelling at each end as a rule passing evenly into the shaft; this lattei is sometimes somewhat poly- tylote. Also with regard to this spicule the length varies somewhat from individual to individual and follows herein the variation of the styles; the length lies in .ill between 0-25 and o-47m,n, generally it is 0-32 — o-4i""". The diameter is about 0*003 o*c©6inin, but sometimes does not reach the lattei - PORIFERA. III. The fully developed tylotes have about equal ends, but single developmental stages were seen, distinctly showing, that the tylote originally is monaetinal. b. Microsclera; there is only one form, rhaphides; they have the special shape which is probably common to all the rhaphides in the species of Tcdcmia. One end is short and curiously, obliquely pointed, while the other end tapers into a long, very fine apex; otherwise they are spinulous which under a low magnification is only seen as an indistinct fine creuu- lation; under a greater magnifying power it is on the contrary seen, that they are distinctly spined, the spines being dentiform and strongly compressed in the longitudinal direction; the smaller rhaphides are the relatively most strongly spined (PI. IV fig. i c). The length varies to a very high degree in the single individual, and also somewhat from individual to individual; it is in all 0-053 — o-50mm, gen- erally it is 0-060— 032 mm. Whether these different sizes are developmental stages it is difficult to de- cide, but it is most probable, that they are, at all events for a great part, fully developed forms. To be sure all intermediate sizes are seen between the given sizes, but certain sizes seem to predominate and I am inclined to think, that three different, independent sizes are present (PI. IV fig. 1 c). When intermediate sizes are found between them, this may be due partly to the variation of the single sizes, but perhaps also partly to the fact, that a number of developmental stages are present among them. The thickness is, in relation to the length, about o-ooio— 0-0028 mm; the latter thickness was only reached by the longest rhaphides and consequently not found in all individuals. The rhaphides occur in great multitude both in the dermis, and otherwise in the tissue of the sponge; they occur both in dragmata and singly and scattered; I have however only seen the large rhaphides in drag- mata; all rhaphides in a bundle seem to have the equal ends turned in the same direction. To show the variation in the length of the different spicules in various individuals and how the lengths with regard to all three forms of spicules are in the main related to each other I may- give some measurements: Styles tylotes rhapides 0-30— o-35mm 0-25—0-32""" °'°55 — o-25mm (small specimen). 0-35— 0-47 mm 0-27— 033 ,nm 0-053— 0-29 mm 0-44 — o-49mm 0-31 — 0-38 mm 0064— 0320 mm 0-43— 0-53 mm 0-35— 0-41 "im 0-064 — o-329m,n 0-51— o-68mra 0-35— 0'47m,n 0-064— °'5° ,nm Remarks: As Schmidt's type-specimen is found in my material, the identification is certain. I have also examined a type-specimen of Tedania increscens O. Schmidt, and have thus been able to decide "with certainty, that this species is identical with sue tor ia. Thiele thinks 1. c. that increscens might be a good species, because its styles are larger than the measurements given by Schmidt for suctoria; but the variations of the spicules given above show however, that from this no character can be drawn. Topsent himself (Rev. Suisse de Zool. IV, 1897, 454) has abolished Tedania conuligera as identical with suctoria, and his description also shows, that this is correct. The specific characters for the species of Tedania seem especially to lie in the shape of the dermal tylotes, and this is not astonishing, as the dermal spicules in other Myxillrce are also characteristic. Besides T. suctoria I have examined '/'. digitata (). Schmidt, tenuicapitata Ridl. and massa R. and D., and of these species I have examined specimens of suctoria from the whole Ingolf territory and from the Willem Barents PORIFERA. III. Expedition, and of digitata from Trieste, Senegal and the Antilles, and I have in these found the dermal spicules characteristic and constant. T. suctoria has tylota with generally weak and elongated end-swellings, /'. digitata has tylota with mure or less weak end-swellings bearing some spines on the end, T. tenuicapitata has tornota, and when Ridley and Dendy say iChall. Rep. Monaxonida, 52), that the dermal spicules in this species may also have round end-swellings, but in a foot-note declare, that snch spicules were only found in one specimen, in which also tornotes occur- red, then no doubt a mistake or confusion must have taken place. Finally 7'. massa has dermal spi- cules which may best be termed strongyla but with a little mucro on the end, and the latter may be quite slightly swollen. The rhaphides in the species of Tedania have been somewhat differently understood; Schmidt only mentions them as "feine umspitzige Nadeln", but does not mention, that they are spinulous; this fact is first stated by Ridley (Proc. Zool. Soe. 1881, 124) in the description of T. tenuicapitata and in the same place the author explains, that such is also the case in a couple of Bower bank's species (aspcra and rudis) and in suctoria O. Schmidt; the author speakes of it as "roughness", and saj s that it is distinct from "spiuation" or "microspination". Later the fine spinulation of the rha- phides is mentioned by several authors as Carter, Ridley and Dendy, Lambe, Top-cut. I.iud- gren and Thiele. In the four species I have examined, the rhaphides are mainly of the same shape, and they are always finely spinulous in all specimens; I take it therefore as very probable that the Tcda /////-rhaphides are always spinulous, and I consider it as certain, that smooth and spinulous rhaphi cannot occur in different individuals of the same species. Ridley describes originally the rhaphides in T. tenuicapitata as "roughened almost imperceptibly", but in the Chall. Report it is declared, that the authors in the specimens which they then had for examination had only found spinulation of the rhaphides in one specimen and moreover only in a spiculum which was not fully developed; I have however examined specimens of T. temncapitaia from the Challenger Expedition and found the rha- phides spinulous; the spinulation is fine, but rather well distinguishable already by a magnifying power of 300; when the authors have seen the spinulation in a small spiculum, this i> easily under- stood, as in the small rhaphides it is most distinct, and, as said above, it is also probable, that the small rhaphides are not developmental stages, but fully developed spicules. With regard to the rha- phides in T. iinissa the authors say: "they often exhibit .1 roughening of the surface..."; my exami- nation of the species showed, that the rhaphides are always spinulous. About the rhaphides in /'. commixta, infundibuliformis and actiniiformis Ridley and Dendy do not mention whether the) spinulous or not, but as spinulation is not mentioned, it has probabh not been seen; it is yet un- doubtedly present. Topsent records (Rev. Suisse de Zool. IV, [897, 454) a '/'. digitata and says, that he refers it to this species, though it has spinulous rhaphides, which have not been described with regard to 7'. digitata; this however is not correct, as Carter already in [886 (Ann. Mag. Xat. Hist. 5, XVII, 52) has declared, that the rhaphides in /'. digitata are spinulous. Topsent is therefore of the opinion, that the rhaphides in 7'. digitata, and on account of the dec], nation of Ridlej and Dendy, also in massa and tenuicapitata and moreover in suctoria, arc able to vary, being either smooth or spinulous; according to what has been said above it must be considered a- certain, that they are always spinulous. A statement of I.iudgren (Zool. Jahrb. XI, 1898, 299) about tin variation in the species ol PORIFERA. III. and which is based on the statement, that: "Topsent dargethan, dass die Raphides bei dieser Art sowohl glatt als auch stachelig sein konnen", therefore loses its relevancy. Thiele describes in 1903 (Abhandl. Senckenb. nat. Gesell. XXV, 945—947, Taf. XXVIII, Fig. 12 — 15) four new species of Tedania; about one of these is stated, that it has distinctly spinulous rhaphides, with regard to two others is said respectively "ziemlieh glatt" and "kaum rauh"; only about the fourth it is said, that the rhaphides are smooth; I think that a sufficient magnifying power would show, that they all have spinulous rhaphides. In 1905 the same author further describes (Zool. Jahrb. VI, 430—33, Taf. 30, Fig. 50—53) four new species; these are declared to have spinulous rhaphides, only with regard to one this is not mentioned. With regard to the forms mentioned by Baer (Arch, fur Naturgesch. 72, I, 1906, 17 — 19) as T. digitata varr. sansibarensis, fragilis and conica the rhaphides are ouly spoken of in a few words, and it is not said, that they are spinulous. Topsent describes (Bull, du Mus. d'hist. nat. 1907, 69, and Exp. Autarct. Fr. 1903—05, 30, PL V, fig. 6) a new species T. Charcoti and mentions, that the rhaphides are spinulous; they are present in two forms, of which one is shorter than the other and has a swelling near one end, a shape already noticed by Thiele for one of his species. — Finally I may note that the two species described by Kirkpatrick (Nat. Antarct. Exp. Nat. Hist. IV, 1908, 32 — 33) variolosa and Coitl- mani, and by the author referred to Tedania, are without rhaphides. Still it must be noted, that Ridley and Dendy in the description of T. actiiiiifonuis advance as probable the theory, that the rhaphides in this and in other species of Tedania are develop- mental stages of the dermal spicules; the special shape and the whole structure of the rhaphides, however, show with full certainty, that such cannot at all be the case, and besides the real develop- mental stages of the dermal spicules are not difficult to find. Locality: Of this species we have a very large material from the whole Iugolf territory; station 27, 640 54' Eat N., 550 10' Long. W., depth 393 fathoms; station 34, 650 17' Lat. N, 540 17' Long.W., depth 55 fathoms; station 46, 6i° 32' Lat. N., n° 36' Long. W., depth 720 fathoms; station 52, 630 57' Lat. X., 13° 32' Long. W., depth 420 fathoms; station 54, 63° 08' Lat. N., 15° 40' Long. W., depth 691 fathoms; station 78, 6o° 37' Lat. N, 270 52' Long.W., depth 799 fathoms; station 87, 65° 02' Lat. N., 230 56' Long.W., depth no fathoms; station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; station 94, 640 56' Lat. X., 360 19' Long. W., depth 204 fathoms; station 97, 650 28' Lat. N., 270 39' Long. W., depth 450 fathoms; station 127, 66° 33' Lat. N., 20° 05' Long. W., depth 44 fathoms; further it has been taken in the Davis Strait, depth 100 fathoms (Th. Holm], at East Greenland, depth 100 fathoms (Ryder), Axarfjord on Iceland, depth 20 fathoms, ("Beskytteren" Otterstrom), at the East coast of Iceland, depth 38 fathoms (Horriiig), Borgarfjord on Iceland, depth 85 fathoms, (Hallas, the type-specimen of Schmidt), on 640 56' Lat. N., 11° 48' Long. W., depth 115 fathoms, East of the Faroe Islands, depth 220 fathoms, (Ad. Jensen, the cruise of "M. Sars" 1902), 640 58' Lat. N, i2; 40' Long. W., depth 70 fathoms, (the fishery investigation steamer "Thor"); South-east of Nolso, depth about 70 fathoms, (Th. Mortensen), between the Faroe Islands and .Shetland Islands, depth 255 fathoms (Wandel); in all about 25 larger and smaller speci- mens. The localities are situated in the Davis Strait, the Denmark Strait, North, East and South of Iceland, between Iceland and the Faroe Islands, at the latter and between these and the Shetland Islands. v ■/-. dislr. The species has earlier been taken South-west of Bukenfjord, Norway, depth 106 fathoms (Schmidt), the Barents Sea, depths 112, 128 and 180 fathoms ("Willem Bareut"), off New- PORIFERA. III. foundland, 460 50' Lat. N., 500 12' Long. W., depth 82 fathoms and at the Azores in depths of 318 and 664 fathoms (Topsent). The species is thus distributed between 74 36' and 38 35' Lat N. and between 360 Long. E. and 560 Long. W. The bathymetrical range varies somewhat greatly, from 20 fathoms (Axarfjord, Iceland) to 799 fathoms (station 78, on the eastern slope of the Revkjames Rid; Histoderma Cart. Sponges of more or less bladder-like consistence ; flic shape globular or roundish in the free, not attached forms, more flattened in the attached forms. The body provided with somewhat long tubular fistula, or with shorter or longer papilltc. An outer, solid dermal /aver present, furnished with a skel- eton of close-lying spicules. The skeleton of the inner body formed of partly regularly arranged, thin fibres, not forming a reticulation, or of more scattered spicules. Spongin not present. Spicula: mega- sclera only of one form, the same in the dermal layer and the inner body, they are diactinal, tylota, stron- gyla or tornota, sometimes the ends are unequal, the spicules then being tylostrongyla or tylolomata; mtcrosclera : the characteristic microsclera are cliche arcua/ic: to these slgmala are generally added, and fur/her trichodragmata may occur; the sigmata may be of one or two sizes, and a peculiar small chela may occur (navicelligerum). 1. H. appendiculatum Cart. PI. I Figs. 6-1 1, PI. IV, Fig. 2. 1874. Histoderma appendiculatum Carter, Ann. Mag. Nat. Hist. 4. XIV, 220, PL XIV, figs. 23— 25, PI. XV, figs. 39 a— b. Globular or more irregularly tuberous, provided with more or less- numerous, tubular fistula:; free, not attached. Surface smooth. The body surrounded by a solid, bladder-like dermal layer. Oscu/a in the apex of some of the fistula, pores in the apex of others. The dermal skeleton formed of close-lying, tangential spicules in several layers ; the skeleton of the inner body consisting of thin fibres, running irregularly, being regular only at the surface and parallel with flits; there are no transverse fibres. Spicula: megasclera tylota passing by intermediate stages into unequal-ended stror, ,""".• microsclera two forms, cliche arcuahe o'0^o—o'0^6mm, ngmata (ro^y—cropj""". Of this curious and interesting species — the type on which Carter founded the genus the Ingolf-Expedition has taken a somewhat rich material. The shape is in the whole as described by Carter; the sponge consists of a globular or tuberous body, from which some few shorter or longer tubular fistuke issue. The body may be nearly quite globular, which especially seems to be the case witli the smaller individuals, but generally it is of a more or less irregular shape, often some- what flattened. The fistuke are, in the specimens to hand, in most eases broken off, only some single ones are whole; they are cylindrical and straight or more or less curved, the sponge thus strongly reminds one of a potato with stolons; it grows freely, without attachment. The body has in the largest speci- men a diameter of 20""" and in the smallest of 8mm; the length of the undamaged fistulse is about 25""", they are of the same length in the small as in the large .specimens, while on the other hand the 8 PORIEERA. III. thickness is somewhat different, from 2 to 4""" in proportion to the size of the specimen. The colour is 1 in spirit ) yellowish white. The consistency is hard and firm, the dermal rind forming a very firm layer, the inner body on the contrary is soft; in most specimens the inner body has therefore con- tracted strongly under the influence of the alcohol and lies like a clump in one side of the firm capsule formed of the dermal layer. By exsiccation the tissue of the inner body contracts strongly, becomes hard and of a yellow colour, so that it resembles wax, just as is mentioned with regard to the tissue of the inner body in Occanapia robusta (The Ingolf-Expedition VI, 1, Porifera, part I, 79). The surface is smooth, only showing such a slight roughness as may be caused by the spicules imbedded in the dermal layer and parallel to the surface. The sponge has outermost a very solid dermal layer of a thickness of about o-25mm; in places it may become thicker, up to imm; it surrounds the inner body like a mail and is very easily loosened from it, and contains close-lying spicules in several layers. Pores and oscula: Carter says: "Pores and vents not distinctly seen, but probably situated at the extremities of the tubuli respectively". This is also the case, but I too cannot solve the question with full certainty, because most of the tubular appendages are broken off. The oscula are certainly situated at the end of some of the fistula;; these latter are tubular, hollow and somewhat thin-walled; a couple of them give the impression of being undamaged, and these terminate with a simple opening which in consequence should be the osculum; a couple of the fistula; terminate with a formation quite as described by Carter, it is with a conical spout, placed at the end of the fistula; whether this is possibly the normal, closed osculum I do not venture to decide. Of poriferous fistula; there is in the material only one present, a loose tube which is broken off and has a length of 20 mm; this tube shows, that the fistula; become more thin-walled outwards, and that the skeleton in the wall becomes more scattered. The end of the fistula is rounded and forms a slightly swollen knob of a length of about 2'5""n; in this knob the skeleton of the wall is transformed and passes into the formation of a reti- culation, in the meshes of which the pores are situated (PI. I, fig. 11); the pores are oval or circular, of a diameter of 0-047 — °'17 wm- I'1 tne dermal layer on the other parts of the body no pores are found. — As mentioned the inner body is inclined to get strongly contracted in alcohol and become hard and brittle, and there is then a large hollow space inside the dermal layer. But in single cases the inner body has on the contrary preserved its original shape and consistency; it then quite fills out the cavity formed by the dermal layer. When a section is made of such a well preserved speci- men, the canal system is shown; some large canals are seen terminating in some of the tubes, and thus shown to be excurrent canals (PI. I, fig. 8); besides, a multitude of smaller canals are seen. The inner body lies quite loose in the cavity within the dermal rind, and it seems only to be attached at the points where the fistulae issue; thus there are extended spaces below the dermal layer. The lumen of the fistulae is not directly continued into the canals of the inner body, as there is a diaphragm present at the origin of the fistula;; this diaphragm has in some cases a circular opening in the centre, but it seemed in other cases to be quite closed. When the dermal rind is removed, the surface of the inner body is shown; this surface is then quite undamaged, and it has the netted appearance which is so often seen on the surface of species of Reniera (PI. I, fig. 9); on examining a specimen which wanted the dermal layer, one might, therefore, think that it must be an entire and un- damaged sponge. The netted appearance of the surface is due to the same cause as in the species of PORIFERA. III. Reniera, being caused by the close-lying, circular openings of the incurrent canals which shine through the thin, transparent outer layer, in which there are tine pores leading to the canals. The poriferous fistula? probably do not lead into canals, but are in connection with the space below the dermal layer; perhaps it is these fistuke whose diaphragm shows no opening in the centre. The coursi the water-current will then probably be: it passes in through the poriferous fistula.- into the space below the dermal layer, from here through the pore-shaped openings on the surface of the inner body and into the canal system, then in due course passing into the larger canals and finally out through the oscular fistulse. The skeleton. The dermal skeleton; the outer rind is highly provided with spicules lying very closely and in several layers, parallel to the surface; the spicules are not scattered, but arranged somewhat circularly round the bases of the fistuke, as is already distinctly visible with a lens; on the inner side of the rind there are some spicules which lie singly and rectangularly to the direction of the other spicules, and thus more or less radiating in relation to the circlets. In the fistuke the ring-like arrangement of the spicules is retained, which is the cause why the fistuke are very easily broken; some fine fibres, consisting of few spicules, run lengthwise out through the fistulse, lying on the inside of the wall, and continue from the base to the end of the fistulse in longitudinal direction; these fibres do not belong- to the dermal skeleton, in so far as thev are not found in the dermal layer of the body, on the contrary they issue from the inner body, and they are probably of importance in attaching it, and thus it is that the inner body, as said above, is attached only at the bases of the fistulse. In the ends of the fistuke the dermal skeleton gets more scattered, and in the oscular fistulse the spicules are here irregularly scattered, crossing each other, while in the poriferous fistuke the skeleton outwards first becomes somewhat scattered, but outermost forms a reticulation. The main skeleton or the skeleton of the inner body: In the inner body some fine fibres are found, but they have no regular course and form no reticulation; they seem mainly to run in directions parallel to the surface. At the very surface of the inner body such fibres are found numerously, running just below the surface and parallel with this, and they show a definite arrangement They run together at the bases of the fistuke and continue, as said before, out in the fistuke; as they radiate from the base of the fistuke out in the surface, they become in the larger part oi this parallel with each other, but at places where the systems belonging t<> different fistula- meet, the fibres run in different directions. Transverse fibres are not found, and thus there is no reticulation formed. The fibres are somewhat loose, they have an average thickness of o-05mm, ami the distance between them is generally 0-15- o-25'"m. — It was said above, that the innei body lies loose in the cavity of the dermal layer; as the fibres mentioned continue from the fistuke inwards and form a carpentry along the surface of the inner body, this latter is in reality kept in its place by this carpentry, otherwise lying freely in the cavity and only attached at the bases of the fistuke. - was not observed, neither in the inner skeleton nor in the dermal skeleton. Carter has not seen the construction of the skeleton of the inner body; in his material the inner body has probably 1 destroyed. P>oth 111 the dermal layer and in the inner body main foreign panicles are imbedded, especially Globigerinae. Spicula: a. Megasclera; these are onlj of one form, t\h>tes, but with some single intermediates Tin- [ngolf-Expedition, VI. (. IO PORIFERA. III. to strongyles. They are more or less curved, but rather slightly; the shaft is thickest at the middle and tapers somewhat towards the ends. The spicules vary very much in size, aud at the same time somewhat in shape; the smaller and thinner they are, the more distinct are the end-swellings; these smaller spicules have equal or nearly equal ends; the larger and thicker the spicules are, the smaller are relatively the end-swellings, so that in the largest of the spicules they may be only slightly pronounced; in the largest spicules the ends are most often not equal, one has a somewhat roundish swelling the other an elongated swelling tapering slightly outwards; not rarely the swellings quite disappear, and then we get a strongyle with unequal ends, one rounded the other more tapering, nearly truncately pointed. The various sizes must be taken to be fully developed spicules, since fine developmental stages in various lengths are found; the developmental stages have unequal ends, the shaft being a little thicker in one end but a little thinner in the other, and here with a more marked swelling. Quite single very fine developmental stages were found, which had one end quite pointed. The length of the spicules is in all 0-27— 0-95""", with a diameter of 0-005 — cvo2imm. The length of the spicules is different in the different parts of the sponge; in the dermal layer the largest are found, wdiile the smaller and smallest are found in the inner body, the separation is how- ever not quite sharp. In the inner body they generally do not exceed 060 m,n, and about at the same size also lies the lower limit for the spicules of the dermal layer. In the skeleton of the fistulae large and small spicules are mingled. In the fibres running along the surface of the inner body the spicules belong for the most part to the larger forms of the group with the smaller spicules, and among them some of the largest spicules are found, and with this composition the fibres continue out through the fistulae. Carter mentions and figures two forms of megasclera; to this result he arrives only by taking a pronounced tylote and a form without end-swellings, and in which one end is truncately pointed; a form such as his figure 39a may be found, but not frequently, and there is, as said, only one kind of megasclera. b. Microsclera; there are two forms, chela; areuatse and sigmata. 1. The chelae arcuats have an evenly curved shaft, lobe-shaped alae and an elliptical tooth; their length is 0-040— 0-046 mm and the diameter of the shaft is 0-004 mm. 2- The sigmata are of common shape and more or less contorted; they are rather large, but they vary somewhat in size, the length is 0-047 — °'°93 ,nri and the thickness 0-0028 — 00057 ram. The microsclera are present through the whole sponge, they are scattered in the inner body and in the dermal layer strewn rather numerously among the megascleres, and they are specially numerous on the inside of the fistulae; the sigmates are everywhere more numerous than the chelse. ■Embryos. In one of the specimens which was cut through an embryo was found, lying in a cavity in the inner body. It was globular and rather large, 3",m in diameter. It was lying in the cavity distinctly surrounded by a membrane. It was richly provided with spicules, both megasclera and microsclera. The megasclera were fine tylotes of a greatest length of about 0"47miD, many of them were very thin and had still one end pointed. They were scattered in the interior of the embryo, but they were already close-lying at the surface and parallel to this, thus forming a layer with how- ever no boundary inwards. The microsclera were developmental forms of cheke in various stages, they were of somewhat different sizes, but reached a length of up to o-o57m,n, thus to a greater size than in the fully developed sponge. Sigmates were not seen. PORIFERA. III. j j We have a specimen of this species which I at first thought was a distinct form on account of its smaller spicules, but which on closer examination proved to Ik* a very young specimen appendiculatum. The specimen is globular, with a single fistula, and very small, about 3,nm in diameter, and thus not larger than the examined embryo. It shows quite the same structure as the full-grown specimens; it has a distinct dermal layer with subdermal cavities below, and also distinctly shows the skeletal structure of the inner body. The specimen is interesting in showing, that such small specimens may have considerably smaller spicules than the grown specimens. It is yet no doubt only the very small specimens which show in this respect any difference worth mentioning, and it is certainly the case, that they very soon get spicules of the size normal to the species. The examined specimen has probably just left the mother-sponge. The megacleres do not reach beyond o-4imm, the chelae are o-05omm, and the sigmates are of the same sizes as in the full grown sponge. It is interesting t<> notice, that the chela; in this specimen are intermediate in size between the chelae in the embryo and those in the grown sponge. The relatively long and fine megascleres in the embryo seem here to be replaced by shorter but thicker spicules. Locality: Station 78, 6o° 37' Lat. N., 270 52' Long. W., depth 799 fathoms, about 20 more or less damaged specimens; station 90, 640 45' Lat. N„ 290 06' Long. W., depth 568 fathoms, two specimens and some loose fistulse; further at 6i° 15' Lat. N., 9° 35' Long. W., depth 478 fathoms, a very small specimen (The fishery investigation steamer "Thor"). The localities are situated on the eastern slope of the Reykjances Ridge, in the Denmark Strait and West of the Faroe Islands. Geogr. distr.: Carter had the species from the west coast of Ireland, depths 808 and 109 fathoms. (Porcupine). 2. H. physa O. Schmidt. PI. I Figs. 12 — 13, PL IV, Fig. 3. 1875. Desmacidon physa < >. Schmidt, Jahresber. der Comm. zur wissensch. Unters. deutsch. Meere in Kiel fur 1872—73, 118, Taf. I. Fig. 8-9. 1887. Cornulum ascidioides Fristedt, Vega Exp. wetensk. Jakttag. IV, 495. PI. 25, figs. 1—2, pi. 29, fig. 21. 1903. Histoderma physa, Arnesen. Berg. Mus. Aarbog 1903, 16, Taf. II, Fig. 5, Taf. III. Fig. 9. 1903. , Thiele, Arch, fur Naturgesch. Jahrg. 1903, 385, Taf. XXI, Fig. 16a— b. 1909. — — , Lundbeck. Meddel. 0111 Gronland, XXIX, 443. Roundish or more irregular, sometimes somewhat erect, attached with a broad b<: vided with cue or a couple of conical sptatts. Surface smooth. The sponge surrounded by a solid, but not thick, bladdery dermal layer. Oscula at the summit of the conical spouts, the pores on the side < The dermal skeleton formed of close-lying spicules parallel to the surface. 'The skeleton of the inner body consisting 0/ fine fibres and bundles of spicules, running irregularly, but at the surface parallel with this: without transverse fibres. Spicula: Megasclcra strongyla with intermediates , o-jo—o-Sp"""; microsclera of two forms, cliche arcuatm omojj—o-ojS""", trichodragmata o-n—o-/2 This species has a shape mainlj as described by Schmidt. It consists (on account of con- traction or destruction of the inner body) of a bladder, formed of the dermal layer. This bladder maj I2 PORIFBRA. III. be more or less roundish or of a more irregular, sometimes somewhat erect shape. The largest specimen in my material has a greatest extent of fully 30mm; it has two spout-shaped tubes and a height of iS",m from the base to the end of the tubes; the smallest specimen has an extent of about 5""". My specimens are attached to stones with a broad base, one is growing on a crab. The con- sistency of the outer layer is firm and hard; the inner body is brittle; in all specimens the latter is contracted and forms only a clump at the base of the bladder, and the same can be seen to have been the case with the specimen figured by Schmidt. The colour (in spirit) is whitish. The surface is smooth. Outermost is found the dermal layer, it is constructed mainly in the same way as in the preceding species, and has a thickness of about o'i5'nm. Pores and oscula: My specimens are all in a rather bad condition, so that the examination of the arrangement of the pores and oscula, which would seem to be rather interesting, may be somewhat deficient, and as the inner body is destroyed, we get from this no information about the canal system. Only the largest specimen is in such a condition, that it gives some information about pores and oscula, and I think, that the structures shown by this specimen are typical for the species, especially as the figure given by Schmidt seems to show a quite similar structure. This specimen has, as said, two tubular or conical spouts, formed of the dermal layer; these spouts have a shape as shown on PL I figs. 12 — 13. The osculum is found as a simple opening at the summit of the conical end part of the spout; the spicules of the dermal layer lie parallel with each other here and with one end towards the oscular opening. On the side of the tube is found a circular opening, surrounded by a low, projecting wall; the opening is covered by the poriferous membrane. The skeleton of the dermal layer forms here a reticulation, as fibres go inwards from the edge of the wall and support the membrane. The pores are numerously present in the membrane, they are small, of an average diameter of o-o6mm. The skeleton. The dermal skeleton; as in the preceding species we find outermost a firm dermal rind which, however, in the present species is somewhat thinner and less solid than in appen- dieulatum. It is provided with close-lying spicules parallel to the surface, and the spicules lie in several layers; they are mainly more or less parallel to each other, but there are also, especially on both surfaces of the layer, spicules present, both in bundles and lying singly, which are scattered and cross the other spicules in all directions. The main skeleton; on account of the condition of the material I have only been able to examine the skeleton of the inner body somewhat incompletely, it seems however to be constructed quite as in appendieulafum ; in the interior there are fibres and bundles, and at the surface there are parallel fibres without transverse fibres; the fibres were measured to a thickness of croS""1' with a distance between them of o-2o,mm. Spongin is not present in the skeleton. S pi at la. a. Megasclera; these are of one form, strongyles, sometimes approaching to subtylotes; they are slightly curved, generally irregularly and most frequently doubly. They are fusiform, tapering somewhat towards each end. The length when all examined specimens are considered is 0-50— o-89mm, and the thickness crooS— o-020mm, but in the single individuals they do not vary so much, as examples may be given 0-50— 074""" with thickness of croo8 — o-oi5""n and 0-62 —0-89 ",m with thickness of o-oio— o-020mm. Fine developmental stages are seen singly, the finest are monactinal. b. Microsclera; these are of two forms, chelae arcuatse and trichodragmata. 1. The chelse arcuatse are of the common shape, PORIFERA. III. the shaft not much curved with the curvature- mainly lying in the middle, the alae and tooth are of the same length, the tooth narrowly elliptical with a long, narrow tuberculum. In all the length is between 0-035 anc^ o-05Smm with a diameter of the shaft of 0-0028— 0-007 mm, Dut tne chelae also vary somewhat in different individuals, e. g. 0035— 0-043 """» °"°45— °'°54 """ aml 0050— 0-058 mm, and the diameter of the shaft may be 0-0028— 0-004""" ailu- 0-004— 0-007 mm. 2- The trichodragmata; the single rhaphides are exceedingly, nearly immeasurably fine, less than o-ooo6ram, the bundles have a length of o-ii— o-i2mm and a thickness of about 002 1—0-035""", tn<-' single rhaphides were measured ; length of about o-io""". The rhaphides seem not to occur singly, but only in bundles. The chelae occur both in the dermal layer and in the inner body, here rather numerously, the trichodragmata are mainly seen in the inner body at its surface. The identification of this, otherwise rather characteristic species, is certain, as I have examined a piece of one of Schmidt's type-specimens. Also of the Cornulum ascidioides Fristedt I have examined a type-specimen and thus been able to decide, that this is the present species; Fristedt has oxer- looked the trichodragmates, and the length, 007 '"'", he gives for the chelae is erroneous, as in his type-specimen I found the chelae to be of a length of 0-058 mm. Locality. Station 6, 63° 43' Lat. N., 140 34' Long. W., depth go fathoms; station 16, 65 \f I. at. X., 26c 58' Long. W., depth 250 fathoms; station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; station 94, 64° 56' Lat. N., 390 19' Long. W., depth 204 fathoms; station 97, 65 28' Lat X., 27 39' Long. \Y.. depth 450 fathoms; further the species lias been taken at 620 26' Lat. N., 4° 49' Long. W., depth 228 fathoms and 62 ' 53' Lat. N., 90 06' Long. W., depth 245 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902); seven specimens or fragments in all. The localities are situated in the Denmark Strait and between Icelands and the Faroe Islands. Geogr. distr. The species has earlier been taken South-west of Bukenfjord, Norway, depth 106 fathoms (Schmidt), Ostfjord at Bergen, depth 292 fathoms (Arnesen), and in Baffin Bay 68 08 Lat. N., 58° 47' Long. W., depth 169—183 fathoms (Fristedt). The southern limit of the species is thus at 59° Lat. N. Histodermella nov. gen. Sponges which in appearance and structure are like Histodcrma; the consistency more or less bladder-like. The shape varies from round or roundish forms through longish to tube-shaped, often slightly branched forms ; the body provided with shorter or longer tube-shaped fistula:, or with shorter papilla:. The sponge surrounded by an outer, very solid dermal layer with close-lying spicules parallel to the surface. The skeleton of the inner body consisting of scattered spicules or irregular fibres, sometimes more regular at the surface, but not forming a reticulation. Spongin not present. Spicula: megasclera of two forms, but these arc intermingled so that the spicules are the same in the dermal layer and the inner body; the megasclera arc diactinal, of the two forms one is smooth, the other spined; the sue megasclera arc I viola or strongyla, sometimes with the ends finely spined, the spined megasclera are acanthoxea or acanthostrongyla. Microsclera may vary somewhat in composition, the charade/. microsc/era are chelm arcuata, to these are added sigmata. and fur/her trichodragmata may besides (natalensis) curious spined bodies (transformed chel • s I sclera may be quite absent. j, PORIFERA. III. i. H. Ingolfi n. sp. PL II, Figs. 1—4, PI. IV, Fig. 4. Of somewhat various shape, more or less roundish with a number of tubiform fistula zviiich may be branched; or of more irregular shape, showing several swellings or finally quite without swellings ; ing freely without attachment. Surface smooth. Outermost a solid, bladder-like dermal layer. Oscula at the summit of some of the tistuhe. [fores at the summit of others?). The skeleton of the dermal layer formed of close-lying spicules parallel with the surface; the inner skeleton consisting of fine. irregularly running fibres, which are regularly arranged at the surface parallel with this, without trans- verse fibres. Spicula: megasclera of two forms, tylota o-2g — o-<5j""", acanihoxea o-// — 0-21"""; microsclcra two forms, cliche arcuatce 0'02i — 0-028""", sigmata 0-056 — 0-06/""". This species in its exterior shape somewhat recalls Histoderma appendiculatum. but it is generally less regular. Most frequently it consists of a more or less roundish body with a varying number of tube-shaped appendages. These appendages or fistulse may vary much in length and thickness, and there are often, besides the larger, also some short and thin fistulas; these may be branched in different ways, and they may be more or less curved; the appendages also may form swellings, the sponge in this case consisting of more than one roundish swollen part connected by the appendages. Finally there are specimens which have no pronounced swelling, or no swelling at all, the sponge then consisting of a somewhat sinuous, slightly branched tube of somewhat different thickness in different places. In the largest specimen the body has a diameter of fully 20""", the longest fistula has a length of 42°™ and its thickness is 4mm; then we have specimens in all sizes down to cpiite small, the smallest one has a body with a diameter of 2'5 mm and a fistula of a length of i4mm and a thickness of 17 mm. The sponge grows freely without any attachment. The colour (in spirit) is yellowish white. The consistency is somewhat bladder-like, the outer layer is hard and firm, the inner body brittle, the latter is as usually highly contracted, so that it only occupies a small part of the cavity within the dermal rind. The surface is mainly smooth, yet the ends of the tangential spicules of the dermal layer ma)- sometimes be a little projecting. The sponge is outermost sur- rounded by a solid and hard dermal layer, formed of close-lying spicules, the layer has a thickness of about o-2""". Oscula and pores: A part of the fistulas are distinctly seen to be oscular fistula;, they terminate with a simple opening, or they are in most cases more or less closed and terminate in a conically pointed part which is either quite closed or shows an opening at the summit. Pores I have not observed, but they are certainly placed at the end of some of the fistulas; in my material however the outer part of these is often broken off; at all events pores are not found otherwise on the body. The inner body is in nearly all specimens strongly contracted or quite destroyed, yet in some single specimens it may be seen to have had a surface as in Histoderma appendiculatum, with pores leading into canals; the direction of the water-current therefore is probably the same as in that species. The skeh ton. The dermal skeleton : the skeleton of the dermal layer is constructed as in PI. appendiculatum; it consists of close-lying tangential spicules in several layers, the spicules are more i circularly arranged around the bases of the fistulas, and here likewise, especially on the inside of the layer, we find spicules which lie at right angles to the others, these latter spicules PORIFERA. III. j- being for a great part spined oxea. The skeleton of the fistulse is also here arranged ring-like, but outwards it soon becomes more irregular and scattered; fibres running through the fistulse in longi- tudinal direction are not found here, or they are at all events only very little pronounced and soon dissolved into spicules lying more scattered in the longitudinal direction. The skeleton of the inner body is constructed quite as in //. appendiculatum ; there are fine, parallel fibres running along the surface and without connecting transverse fibres, and they run together at the bases of the Bstulae, some of them may continue out in the fistulse; in the interior of the inner body similar fibres are found, but they are scattered without observable order; besides there is found a number of single, scattered spicules, which for a great part are spined oxea. Spongin could not be observed in the skeleton. Spicula: a. Megasclera; these are of two forms, tylota and acanthoxea. i. The tylota are- straight or slightly curved, they have a well developed swelling at either end, the shaft is thickest in the middle. The length varies much, from 0*29 — 0*65 mm, with a diameter of the shaft relatively of 0-007— 0-017 mm. Some developmental stages are found down to quite fine, the thinnest of them are monactinal, the older show one end rounded or slightly swollen, while the other end has a pointed swelling which represents the original apex, and the shaft is thinnest at this end. There is no differ- ence between the tylotes in the dermal layer and those in the inner body, but the developmental stages are found in the interior. 2. The spined oxea or acanthoxea are curious and characteristic spicules; they are straight or quite slightly curved, and relatively short and thick, the points are middle-long and sharp; the spicule is coarsely spined in the whole length, only the points are smooth to a greater or smaller extent. The length varies from 0-17 — 0-21'"" and the diameter from 0-008 — 0-014. Some single developmental stages were seen, the thinnest of them slightly spined, these had a thickness of 0*004 mm. The tylotes form the dermal layer and the fibres in the inner body are also found scattered singly in the interior; the spined oxea are seen scattered singly in the dermal layer, but are for the rest present, as said, on the inner side of the layer, lying at right angles to the other spicules, further they are found scattered in the inner body. b. Microsclera; these are of two forms, chelse arcuatse and sigmata. 1. The chela; are somewhat small, they have a slightly curved shaft, the alae are incised below and drawn out in a point, the tooth is narrow. The length is 0-021 — o-02Smm, and the thickness of the shaft about 0"OO2mm. Chelse of somewhat deformed shape were not infrequent. 2. The sigmata are rather fine, they are contorted generally about a quarter of a turn; the length is 0-056 — o-o6imm and the thickness 0-002 00028 . The mien occur on the inside of the dermal layer and in the inner body, but they are on the whole not numerous. "Cellules spheruleuses". In this species the so-called cellules spheruleuses occur, often in enormous numbers; they occur especially on the inside of the dermal layer and the fistulse and in the inner body, chiefly at the surface of the latter. They are roundish or more elongate and filled with relatively large, refracting granules; their size is generally <>-,.ii -o-oi; Sometimes they are some- what confluent to larger heaps of granules. Locality: The species has only been taken on station 78, 60 37' Lat N., :;. 52' Long. W., depth 799 fathoms, on the eastern slope of the Reykjanses Ridge; a somewhat large numbei oi specimens. j6 PORIFERA. III. 2. H. coriacea n. sp. PL II, Figs. 5-6, PL IV, Fig. 5. Elongate, somewhat fusiform, sometimes cylindrical or more irregular and somewhat branched ; provided villi generally short, papilla-shaped fistula in greater or smaller number. Growing freely, with- out attachment. Surface somewhat rough, but without projecting spicules. The sponge is surrounded by a very solid dermal layer. Oscula and pores each at the summit of their own papilla?. The dermal skeleton formed of close-lying, tangential spicules. The skeleton of the inner body consisting of scattered spicules. Spicula: megasclera oj two forms, strongyla with spiuulous ends cr2j — ro2m1", acauthostrougyla o-12—o-jjS""". No microsclera. This species has an exterior which certainly resembles that of the preceding species bnt how- ever is somewhat different, and it is larger and more robust. It consists of a body with fistulse, bnt the body is never globular but elongated, generally somewhat fusiform, thickest in the middle and somewhat tapering towards the ends; it is otherwise generally more or less irregular. Sometimes it is not fusiform, and the sponge is then nearly cylindrical; sometimes it is somewhat branched. The fistulae are generally rather short, often nearly papilliform and they are for the rest very irregular both in shape and arrangement, and they may also be branched. When they are somewhat larger they appear as branches, so that the sponge then assumes the branched shape. Most of my specimens are somewhat damaged, but to judge from not damaged specimens the species is not attached, but grows freely, which is also by far the most probable. The largest specimen, which is not quite entire, has a length of about ioomm and a greatest thickness of 17"""; the other specimens are somewhat smaller, down to about 50mm in length. The colour (in spirit) is in most specimens whitish grey or dirty greyish violet, the inner body is darker than the dermal layer and is obscurely reddish violet; some of the smallest specimens are nearly quite white, but also in these the inner body is somewhat darker. Whether the colour is original or due to the influence of alcohol has not been observed. The consistency is, on account of the very thick dermal rind, very firm, the inner body is also in its present condition rather firm, but brittle; it is strongly contracted and lies generally up to one side of the dermal layer. The surface cannot be termed smooth as the close-lying spicules cause it to be rough both to the sight and to the touch, but it has no projecting spicules. The sponge is outermost surrounded by a very solid and hard dermal layer, provided with close-lying spicules; this layer is very thick, from 0*4— 0"8mm. Pores and oscula: Some of the fistulse or papillae are oscular papillae; they are distinguished by their conical shape, pointed towards the end, with an oscular opening at the summit. The papilliform ends of the sponge-body itself are oscular papillae. From the oscular opening a canal, which is surrounded by a film-like membrane, leads down into the bod}'. The other papillae, which bear no oscula, are pore-papillae. These fistulae or papillae are of a different shape from the oscular papillae, they have rounded ends which are as a rule a little swollen; they are present in greater numbers than the oscular papillae. The pores are only present in the outermost, rounded end-part of the papillae. In the middle, through the interior tissue of the papilla, runs a canal which in the outer end-part of the papilla is divided into branches; these branches go to the surface and are the incurrent canals into which the pores lead; these latter are lying in an irregular reticulation PORIFERA. III. and they have a diameter of 0-036—0-10""". The circulation of the water-current is then the same, as was mentioned under //. appendiculatum ; there is also here a space below the dermal rind, and in a section of the inner body parallel with the surface the small, round incurrent openings to the canals are, under the microscope, seen King very closely. The skeleton. The dermal skeleton; the skeleton of the dermal layer is formed of close-lying, tangential spicules, which lie in several layers and form a solid and protective rind. The greatest part of the spicules lie parallel to each other in a direction which goes more or less distinctly circularly round the sponge, thus the spicules lie at right angles to the longitudinal direction of the body of the sponge; at the same time they are, in the environs of the fistula.', arranged ring-like around the bases of these. When the surface is undamaged, there is outermost a layer of more loose- lying spicules which lie crossing each other in all directions; between the regularly arranged spicules of the layer there are spicules placed at right angles to the others. A section through the layer parallel to the ring-like arranged spicules will thus show entire spicules lying parallel to each other on the inside, and cut, irregularly King spicules on the outside. The spined strongyla occur especially at the outer side. The skeleton in the fistuke is ring-like arranged at the base, but outwards it passes soon into an irregular skeleton with spicules intercrossing in all directions; in the oscular fistula; the spicules are in the conical summit arranged parallel to the longitudinal direction and with one end towards the oscular opening; in the pore-fistuke there is at the end an irregular reticulation, in the meshes of which the pores lie. The skeleton of the inner body is difficult to get a clear idea of on account of the brittleuess and contracted condition of the tissue, and also on account of its very dark colour. It is however not regular as in the preceding species, but seems only to consist oi scattered spicules; at the surface they are present in greatest numbers while they are much scattered in the interior, and they are on the whole not numerous. Spongin is not present in the skeleton. Spicula: a. Megasclera; these are of two forms, smooth strongyla and acanthostrongyla. 1. The smooth strongyla are straight, more rarely quite slightly curved, they are thickest in the middle and taper slightly towards the rounded ends, which latter sometimes may be quite slightly swollen. The ends are very finely spinulous on the rounded part; the spiuulation may be ver) little apparent but is generally rather distinct, it is most obvious 011 the smaller spicules. The length varies much, from 0-24""" and up to 1-02 """, and the thickness is < >-oo8— 0-021""". In the dermal layei strongyla of all sizes are found, the larger are present in greatest numbers, in the inner body on the contrary only the smaller forms are found, up to a length of 0-47" , but at the surface of the inner body the) somewhat larger up to 0-71""". 2. The acanthostrongyla or spined strongyla are relativeh short and thick; they are generally sligtly curved, coarsely spined strongyla, sometimes each end terminates in a point, but as this is not. or only very slightly, larger than the other spines, i be taken as such and the spicule must be termed a strongyle. The length is about. >u 0-238 . the shortest forms occur most rarely, the thickness is i.-uii 11017' '. The acanthostrongyla occur both in the dermal layer and the inner body scattered between the other spicules; in the dermal layer the\ are especially present towards the outer side. Microsclera are not present. Locality: This is the same as for the preceding species, viz. station 78, 60 37' Lat. N„ Long. W., depth 799 fathoms. The [ngolf-Gxpedition, VI \, ,s PORIFKRA. III. Tliis species seems to be very like Phloeodictyon birotuliferum Cart. (Ann. Mag. Nat. Hist. 5, XVIII, 447), to judge from Carter's figure and description. This resemblance however is probably only an analogy, without consequence in regard to affinity of the species (see below under the remarks about the species of the genera in question). The two Histodermella species established here, Ingolfi and coriacea, are certainly rather nearly related to each other; the outer shape, the dermal rind and the arrangement of the canal system are in agreement; the differences lie mainly in the construction of the skeleton of the inner body and the shape of the spined megasclera as also in the absence of microsclera in one species. Inflatella O. Schmidt. (Joyeuxia Topsent.) The shape roundish or the sponge more or less club-shaped, sometimes pedunculated. The con- sistency bladder-like. The body provided with more or less numerous papillae. An outer, solid dermal layer present, with a skeleton of close-lying spicules ; the skeleton in the inner body weak, consisting of thin fibres, not forming any reticulation. Spongin not present. Spicula; Megasclera of one form, diactinal. strougyla; microsclera not present. 1. I. pellicula O. Schmidt. PI. II, Figs. 7—9, PL IV, Fig. 6. [875. Inflatella pellicula O. Schmidt, Jahresber. der Comm. zur wissensch. Unters. der deutsch. Meer. in Kiel fiir 1872—73, 117, Taf. I, Fig. 5. 1885. Reniera in data Armauer Hansen, The Norwegian North-Atlant. Exp. XIII, Spongiadae, 7, PI. I, fig. 4. 1903. Inflatella pellicula. Thiele, Arch, fiir Naturgesch., 1903, 385, Taf. XXI, Fig. 17. 1904. foyeuxia viridis Topsent, Resultats des camp, scient. du Prince de Monaco, Fasc. XXV, 205, PL III, fig. 12. ( 'tut)- or fear-shaped, pedunculated, with some few conical papilla above. The s?trface smooth. The sponge surrounded by a solid dermal layer. Oscula and pores at the summit of the papilla. The dermal skeleton formed of close-lying, tangential spicules; the inner skeleton consisting of bundles or /nose fibres. Spicula: Megasclera strougyla 0-42 — o-6j""". The outer shape of this species is somewhat well known from the descriptions cited. It is elongate, pear-shaped and is attached below by a shorter or longer peduncle to a substratum. The peduncle may with regard to the manner of fixation be somewhat various; either it is only fixed by means of a little dilatation, or it emits stolons which may shoot out at various heights, and each of which has its own attachment. This is alreadv mentioned by Schmidt 1. c. Of the figures cited above that given by Schmidt shows stolons, while the others show a single peduncle; the figure by Topsent, however, shows a small projection above on the peduncle, evidently a beginning stolon, as is also mentioned by the author. Above, the peduncle passes into the pear-shaped body which hears one to four slender, conical papillae above. The specimen described by Topsent shows an osculum without papilla. Of the specimens in my material the largest is 19 mm, the smallest ion,m high; PORIFERA III. I(. the specimens previously described are of similar sizes. The papillae vary in length from 15 to | The colour (in spirit) is in one specimen green, but otherwise whitish, presumably on account of de- colouration. The consistency is bladdery, the dermal layer being firm and solid, while the inner body is soft and strongly contracted. The surface is smooth. The dermal layer is a rather thin, firm mem- brane, provided with close-lying spicules. Pores and oscula: The pores are certainly found at the summit of certain papillae, as in one of the papillae I found a very distinct, sieve-like pore-membrane with close-lying, circular pores, but as my material is somewhat damaged and only shows few papillae, I can say nothing further, but there are no pores found otherwise on the surface. Some others of the papillae are oscular papillae with a simple opening at the summit. That the papillae are partly oscular, parth- pore-papillae is also confirmed by what is found in the following species /. viria The sktlrttm. The skeleton of the dermal layer consists of close-lving, tangential spicules, inter- crossing each other in all directions; they lie rather closely, but not more closely however than that the membrane may be seen everywhere between them. In the peduncle they lie quite closely and here they are all arranged parallel to the longitudinal direction; the layer is also here considerably thicker, and the spicules lie in several layers; the peduncle, however, is not compact, but the inner cavity continues down through it. In the wall of the papillae the spicules likewise lie quite close to each other and all parallel to the longitudinal direction with one end towards the opening of the pa- pilla. The skeleton of the inner body I have only been able to examine somewhat incompletely, as the specimens in my material for the most part want the inner bodv; it is however not at all devoid of a skeleton; there are bundles and loose fibres present which seem mainly to have a course along the surface, but whether there is otherwise any definite arrangement I have not been able to see. Spongin is not present in the skeleton. Sfticula: a. Megasclera; these are of one form, strougyla; they are slightly, generall) somewhat irregularly curved; they are thickest in the middle and taper a little towards the ends; these lattei are sometimes, either one or both, slightly swollen; there is often a little difference between the ends, one being slightly thinner than the other, but most frequently such a difference is not observable. The length is 0-42— 0-64 mm, most frequently about intermediate between these sizes, the thickness is o-oio— o-oi28'"m. Fine developmental stages were found singly, they are mouactinal, and they are especially found in the inner body. Microsclera not present. As I have examined the type-specimen of the Renicra inflata Arm. Hans, the identification of this with the present species is certain. — While the foyeuxia viridis Tops. (1, c. [904) must be the present species, the two specimens which this author described in 1892 lor the first time (I.e. Fasc. II. 94.), and on which he founded the genus foyeuxia and the species viridis, are on the contran pi a distinct species and identical with the species described below. Locality: The Ingolf-Expedition has taken three specimens of this species on the following localities: station 32, 66° 35' Lat. N., 560 38' Long. W., depth 318 fathoms; station Si, 6] |i l.at. X., 2; Long. W., depth 485 fathoms, and station 97, 65 28' Lat. N., 27 39' Long. W., depth 450 fathoms. The localities lie in the Davis and the Denmark Straits. Geogr. distr. The species has earlier been taken South-west .-I Bukenfjord, Norway, depth fathoms (Schmidt I.e.) and at 38 31' Lat. N., 26 50'Long.W., depth 410 fathoms. The species is thus 20 PORIFERA. III. distributed in the Atlantic Ocean together with the Denmark and Davis Straits between 66° 35' and 51'LatN., and with a bathymetrical range from 106 to 485 fathoms. For the specimens from the Norwegian North-Atlantic Exp. no particular locality is known. 2. I. viridis Tops. PL II, Figs. 1 1- 12, PI. IV, Fig. 7. 1892. Joyeuxia viridis Topsent, Resultats des camp, scient. du Prince de Monaco, Fas c. II, 94, PI. II, fig. 8, PI. X, fig. 19. Erect, somewhat club-shaped, or of a lower and somewhat semiglobular shape; there arc more or less numerous papillae in the upper part. Surface smooth. Outermost there is a solid dermal layer. Oscula and pores each at the summit of their own papilla-. The dermal skeleton formed of close-lying tangential spicules in several layers; the inner skeleton consisting of bundles and thin fibres running parallel with the surface, -without transverse fibres. Spicu/a: Megasclera strongyla o-66 — no""", This species differs from the preceding one externally in being considerably larger and in having no peduncle. Of the specimens in my material only three are tolerably entire; of these the two are erect and somewhat club-shaped, being a little narrowed below, the third is lower and relatively broader. Above, the sponge has more or less numerous conical papillae; below, it has been attached, and it would seem as if it had grown on the bottom itself, the base of attachment being beset with gravel and other small particles. The largest of the entire specimens has a height of 30mni, and a breadth of about 18""1', and at the base a breadth of fully iomra; another specimen of a similar shape is somewhat smaller; the lower and broader specimen has a height of about 20""" with a breadth of about 15""". The colour is (in spirit) light brownish yellow or olive; the colour of the inner body is deeper than that of the dermal layer. The consistency is bladdery, the outer layer hard and firm, the inner body brittle and soft. The surface is smooth. The dermal layer is provided with tangential spicules in several layers, and it is somewhat thicker than in /. pellicula and reaches a thickness of about o-5nira, in places even more. Oscula and pores: the papillse mentioned are partly oscular and partly pore-papillse. The oscular papillse are conical, of a height of 3""", but they may contract themselves and are then quite low. When they are open the osculum is a simple opening at the summit. In the wall of the papillse the spicules are close-lying; they do not lie, however, in the longitudinal direction but in two directions crossing each other almost rectangularly and both obliquely to the longitudinal axis of the papilla; when the papilla is quite extended the two sets of spicules are arranged in rather distinct, but close-lying bands, but when the papilla is contracted and the osculum closed the spicules form a compact mass and when the papilla is then examined from the end the ends of the close-lying spicules are seen. The pore-papillse are of another construction and easily distinguishable from the oscular papillse; they are larger, especially broader, and they are not conical but cylindrical; they are generally placed on the sides of the upper part of the sponge, and they are not directed straight outwards but somewhat upwards so that their opening points upwards, they are at the same time somewhat adpressed in towards the sponge and hence elliptical in circum- ference; the}' have a breadth of 6 — iomm; on account of the manner in which they are attached, their PORIFERA. III. 21 anterior wall is higher than the posterior, which is towards the sponge, e. g. 6 and 31" respectively. The elliptical opening is covered by a somewhat immersed pore-membrane, with very close-lying pores, so that the membrane is sieve-like; the pores have an average diameter of 0-17 . The walls of the papillae are provided with spicules which do not lie in the longitudinal directii in, as is also the case in the oscular papillae; they are here distinctly arranged in two sets of bands crossing each other m. »re 1 n less rectangularl) . and placed more or less obliquely to the longitudinal axis of the papilla; this oblique direction shows for the rest a definite arrangement; while the bands on the hinder side of the papilla form an angle of 450 to the longitudinal axis, those on the anterior side are more- erect and most so on the middle of the anterior side; the bands form by their arrangement a close reticulation with square or subqua- drangular meshes. In the pore-membrane no spicules are found. The oscula are present in greatest number e. g. up to seven, of pore-papilla; on the contrary only one or two are found. | The surface of the inner body shows under the microscope an appearance almost as in Histoderma appendiculatum ; through the surface shine the openings of close-standing incurrent canals; the course of the water- current will thus be through the pore-sieves into the extended subdermal spaces, from here through the fine pores in the surface of the inner body into the canal system, and then out through the oscula. The skeleton. The skeleton of the dermal layer consists of tangential spicules in several layers; the spicules are rather close-lying, but yet the tissue may everywhere be seen between them; they intercross each other in all directions without any observable order, only a slight tendency towards collecting into bundles is seen, with only few spicules in the bundles. The skeleton oi the oscular and pore-papillae is described above. The skeleton a/ the inner body. As in /. pellicula a close examination shows that the inner body also in the present species is provided with a skeleton; in the interior this skeleton consists only of quite single scattered bundles, but on the other hand it forms distinct fibres at the surface, running parallel with this, and it is thus in the main constructed as in the species of Histoderma. As far as I could observe no spongin is found in the skeleton. Spicula: a. Megasclera are of one form, strongyla, they are more 01 less, generally somewhat irregularlv curved, more rarely straight; sometimes the curve is somewhat sharp; they are thickest in the middle and taper somewhat towards the ends but most frequently only to a slight degree. The length varies a deal, from 066— riOmm, they are rather slender, the thickness is in the middle oou 0'0i4n,n'. Fine developmental stages, which are monactinal, are found in the inner body. Embryos. In a couple of specimens embryos weir found; they were lying in the inner body close to the dermal layer; they are globular, of a diameter of about 0-48" : the examined embryos showed no spicules. Whether this species is really identical with Topsent's viridis it is difficult to decide, but as the only difference is, that the spicules in Topsent's species are somewhat smaller, 076 . there good reason to take them as identical. When Topsent declares, that the inner body is quite 'l Since this was written the work of Kirkpatrick (Nat Antarct. Exp. Nat. Hist IV, [908] has here the author describes a very interesting species I B< Hi 1 ixtaj (41, PI. XVI. figs. 1 5 ■> ; this beauti) 1 has on the surface numerous papillae, easily seen to be oscular and pore-papilke; the pore-papilla; are about 1 "» long, trumpet-shaped, with a pore-sieve over the wide opening; the oscular papilla are simple and smaller, about 1 long. In iln- species the facts with regard to oscula and pores are thus principally the same as described abov< til kin. Is of papilla; are much more developed. 22 l'OKIFERA. III. without spicules, these have surely only been overlooked. Topsent's specimen had lost the upper part, and oscula and pores therefore were unknown to him, and consequently it is incorrect, when he says, that pores pierce the dermal layer singly. Locality: Station 92, 640 44' Lat. N., 320 52' Long. W., depth 976 fathoms; about five more or less damaged specimens. Geogr. distr. The species has been taken 250 right south of the Ingolf locality between 380 and Tff Lat. N., at the Azores in depths of 241 and 391 fathoms (Topsent 1. a). Remarks. Topsent says (1. c. 1904, 207) that still another species"belongs to fnflatclla (=Joyeuxia), viz. ascidioides Fristedt; this species, however, is identical with Histoderma physa, as mentioned above under this species. When Topsent says in his generic diagnosis, that chelae may Occur in the genus, this is therefore erroneous. Tnflatella sp. Vosmer (1885. Bijdr. tot. de Dierk. 12" Afl. 3d" Gedeelt. 21, PI. I, fig. 8, PI. V, figs. 17—19) is a Vosmaeria, Cornulum Cart. The shape somewhat various, the sponges bring erect and obconical or more roundish or semi- globular with a broad base. The consistency somewhat bladder-like. With or without fistuhc. Outermost a solid derma/ /aver with close-lying spicules. The skeleton somewhat solid, consisting of rather thick fibres, dendritical or reticulated. Spougiu present. Spicula: Megasclera diactinal. o.xea or strongyla. the latter sometimes with the ends finely spinulous; the megasclera art- either of one form and equal through the whole sponge, or of two forms, oxea in the skeleton and strongyla in the dermal layer; microsclera: the characteristic microsclera are isochelcr palmatce either solely, or (textile) together with toxa. 1. C. textile Cart. PI. II Figs. 13—14, PL V, Fig. 1. 1S76. Cornulum textile Carter, Ann. Mag. Nat. Hist. 4, XVIII, 309, PI. XII, fig. 9, PL XV, figs. 28a-b. [887. — , Fristedt, Vega Exp. vetensk. Jakttag. IV, 446. 1909. — . Lundbeck, Meddel. 0111 Gronland, XXIX, 443. Erect, obconical, with a flat upper surface. Outermost a thin but solid dermal layer. Surface smooth. Oscula lying to one side in the upper, flat plane, pores occupying the rest of the plane. The dermal skeleton formed of rattier close-lying spicules in one layer. The inner skeleton strongly developed, regularly dendritical, consisting of fibres -which go upwards from the base and bend out to the surface, they art- eon meted by transverse fibres. Spicula: Megasclera one form, strongyla with finely spinulous ends, about Above, the fibres spread themselves out and support the membrane oi the upper surface, and the spicules are here a little projecting. As will be seen the skeletal reticulation thus formed is rather regular, and the skeleton is intermediate between a dendritical and a reticulate skeleton. [11 the skeleton a distinct amount of spongin is found, which in most places nia\ be seen to coat the fibres with a ,, PORIFERA. III. layer; spongin is also present in the dermal membrane, and on examination the membrane gives the impression of being quite or partly a spongin-lamella; the spongin of the skeletal fibres continues directly over into the membrane. It is this consistency of the membrane about which Carter uses the expression "a horny sarcodic membrane". In the membrane there are found fine thickenings or slightly elevated lists running circularly round the sponge, they seem to be thickenings of the spongin, and are possibly phenomena of growth. Spicula ■■ a. Megasclera are somewhat curved strongyla, they are thickest in the middle and taper towards the ends, more towards one end than towards the other, and they are thus unequal-ended. The ends are quite slightly spinulous outermost on the rounded part, sometimes they may be smooth. The length is 0-32 — 0-536 mm and the thickness is 0-017— cvo22n,n'. Some finer to quite fine develop- mental stages were seen, the finest are monactinal and thus show that these unequally-ended strongyles originate from styles, b. Microsclera : these are of two forms, isocheloe palmatae and toxae. 1. The chelae palmatae are very small and of the typical shape, the tooth is of the same length as the alae and of the same breadth as these together; the alae seem to be only very slightly refolded laterally so far as I could see under a high magnifying power (x 1400). The length is 0-014 — o-oij""11 and the breadth about 0-0028 mm. 2. The toxa are long and fine, the curvature is most frequently very slight; sometimes they are only curved in the middle, but most frequently also the end parts are slightly recurved; sometimes they ma}' be somewhat irregular, so that their shape as toxa is not distinct; they are of the same thickness in the whole length, only the ends are finely pointed. The length is 0-2 1 — 0-30""" and the thickness about o-ooi6ram. Carter mentions and figures as "subskeleton spicules" some fine spicules, which he terms "acuate", but his figure shows two, of which one is a style, the other pointed at both ends; it is presumably a confusion of developmental stages of the strongyles and toxa which forms his "subskeleton spicules". I have not seen toxa quite so strongly curved as shown by Carter's figure, but no doubt they may vary a good deal in curvature. The microsclera occur everywhere in the soft tissue of the sponge, the chelae are present in very great numbers. Embryos. In one of the specimens an embryo was found; it was situated about in the middle of the sponge and had a size of about o-6mm. It contained numerous megascleres, but there seemed to be no microscleres present. The megascleres are similar to those in the grown sponge, only con- siderably smaller, of a length of about 0-20 mm. Locality: Station 4, 640 07' Lat. N., n° 12' Long. W., depth 237 fathoms; station 143, 620 58' Lat. N., 7 09' Long. W., depth 388 fathoms, (bottom temperature -fo°4C); further it has been taken at 620 40' Lat. N'., i° 56' Long. \V., depth 365 fathoms (bottom temperature ^ o° 3 C), 62° 29' Lat. N., 40 12' Long. W., depth 283 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902); finally it has been taken at East-Green- land, 740 17' Lat. N., 1 50 20' Long. W., depth 127 fathoms (The East-Greenland Exp. 1891 — 92). Five specimens or fragments in all. Geogr. distr. The species was earlier taken on the "Porcupine" Expedition, 6i° io' Lat. N., 2° 21' Loug. W.. depth 345 fathoms (bottom temperature 4- i° 1 C) (Carter 1. a), and in the Baffin Bay, 72°32' Lat. X., 56 05' Long. W., depth 116 fathoms. The species is accordingly distributed between 1° 56' and 56° 05' Long. W., and between 6i° 10' and 740 17' Lat. N., in the Baffin Bay, at East-Greenland and around the Faroe Islands. The depths are from 116—388 fathoms. The species presumably belongs PORIFERA. III. 2.S mainly to the cold area, as the localities, as soon as thev are deeper than 300 fathoms, show a negative temperature, but it may also go higher up and here occur in water with a positive temperature. Remarks about the species of the genera Histoderma, Histodermella, Inflatella and Cornulum: Of species which belong here, or have been supposed to belong here, there are at pr< described the following: 1874. Histoderma appendiculatum Cart, (cited above). . Tylota to strongvla — chehe arcuata.' — sigmata. 1875. Desmacidon fihysa O. Schmidt (cited above). . . . Strongvla - chelae arcuata- trichodragmata. 1875. Inflatella pellicula O. Schmidt (cited above). . . . Strongvla. 1876. Halichondria phlyctenodes Cart. (Ann. Mag. Nat. Hist.4, XVIII, 314, PI. XIII, fig. 17, PL XV, fig. 35) Tornota -- chelaj arcuata.- - sigmata. 1876. Cornulum textile Cart, (cited above) Strongvla with spimtlous ends - • chehe pal- matae — toxa. 1883. Phloeodictyon singaporense Cart. (Ann. Mag. Nat. Hist. 5, XII, 326, PI. XIII, fig. 17 a— b) < >xea -- short strongvla chehe palmatae 1885. Sideroderma navicelligerum Ridley and Dendy, (Challeng. Rep. XX, Monaxonida, 115, PI. VIII, fig. 9, PI. IX, figs. 5, 8— q) Tylota - - small peculiar chela- - sigmata of two sizes — trichodragmata. 1886. Histioderma verrucosum Cart. (Ann. Mag. Nat. Hist. 5, XVIII, 452) Tylostrongyla — chehe arcuata- -- sigmata. 1S86. Histioderma polymasteides Cart. (Ann. Mag. Nat. Hist. 5, XVIII, 453) Tylota to tylotornota -- chelae arcua 1886. Pseudohalichondria clavilobata Cart. (Ann. Mag. Nat. Hist. 5, XVIII, 454) Tylotornota -- chela- arcuata-, curious, spined. 1887. Cornulum ascidioides Frstdt. (cited above) = Histoderma physa. 1887. Cornulum cnteromorphoides Frstdt. (Vega Exp. vetensk. Jakttag. 447, PI. 25, figs. 3 — 6, PI. 29, fig. 22) se below. 1888. Sideroderma Zitteli Lendenf. (The Austral. Mus. Descrip. Catal. of Sponges, 211) Styli -- oxea - chela- rhaphides. 1892. Joyeuxia viridis Tops, (cited above) Strongvla. 1903. Histoderma natalense Kirkpatrick, (Marine Invertebr. in South Africa, III. 250, PI. V, fig. 17, PI. VI, figs. 18 a— e) Tylota acanthoxea chelae arcuatae mat.i trichodragm curious spined bodies (transformed chelae? 01 fori 1904. /byeuxia tubulosa Tops. (Resultats des camp. se. du Prince de Monaco, Fasc. XXV, 206, PI. V, fig. 5, PI. XIV, fig. 16) Strongyla. The IngoM Expedition. VI. 3 26 PORIFERA. III. 1905. Hisloderma vesciculatum Dendy (Rep. of the Pearl ( tyster Fisheries of the Gulf of Manaar, Part III, 166, PI. XI, figs. 8-*g) Oxea — strongyla — chela; palniatae. [908. Joyeuxia Belli Kirkpatrick, (Nat. Antaret. Exp. Nat Hist. IV, 41, PI. XVI, figs. 1— 5 a) Strongyla. Histodermella Ingolfi mihi Tylota — acanthoxea — chelse arcuatae — sigmata. Histodermella coriacea mihi Strongyla with spinulovts ends — acanthostrongyla. < if these species Cornulum ascidioides Frstdt. is shown above to be identical with Hisloderma physa ( >. Schmidt. I have also examined a piece of the type-specimen of Cornulum enteromorphoides Frstdt, and this species proved to be identical with — Myxilla fimbriate/, Bow., which for the rest may alreadv very well be seen from the description. The specimen, which Fristedt had to examine, was of an elongated shape, and this in connection with the rather strong dermal membrane of this species has led him to refer this typical Myxilla species to Cornulum. Hereafter these two species of Cornulum must be dropped. — Sideroderma Zitteli Lendenfeld scarcely belongs to the group of sponges here in question. The remaining species will have to be distributed in the four genera treated above, Histodernia. Histodermella, Infiatella and Cornulum. After Carter had established the genus Cornulum with the typical and sole species textile, this genus has hitherto only contained the same species, the two erroneous species of Fristedt excepted. With a generic diagnosis as given above, in which the distinguishing characters are first the palmate chelse, and next the dendritical or reticulate skeleton, formed of strong fibres, two of the above enumerated species, viz. singaporense1) and vesciculatum must belong to this genus, and the genus seems very natural. Histodermella . which I have founded mainly en characters in the spiculation and for which the typical species is Ingolfi. also includes, besides the two species described here, the Hisloderma natalense established by Kirkpatrick in 1903. The above enumerated species will, according to the facts mentioned, have to be distributed in the following way: Hisloderma: Histodermella: Infiatella: Cornulum: appendiculatum Cart. natalensis Kirkpatr. pellicula O. Schmidt textile Cart. physa < >. Schmidt Ingolfi mihi viridis Tops. singaporense Cart. phlyctenodes Cart, (vide coriacea mihi tubulosa Tops. vesciculatum Dendy. remark on page 27) Belli Kirkpatr. navicelligerum Dendy verrucosum Cart. polymasteides Cart. clavilobatum Cart, (belongs perhaps not here but may be an£speriopsis) Topsent has (I.e. 1904, 198) established a new genus Phlyctaenopora with one species, bistorquis, ') Dendy (1905, 1. c.i has shown, by examination of Carter's type specimen, that the species has chelae. PORIFERA. III. which, according to the author, should be placed near to Histoderma; I cannot express myself tn particularly about this species, but its relationship with the tonus here in question seems to me some- what doubtful. The four genera mentioned are distingushed among the Myxilleae by the megascleres being the same in the dermal skeleton and in the skeleton of the inner body; this at all events holds quite good with regard to Histoderma, Histodermella and Inflatella; among the species oi Cornuhim it holds also good for textile; in singaporense and vesciculatnm there are, to be sure, two forms of megascleres, but they are both diactinal, and they seem not to be sharply divided with regard to their occurrence in the sponge-body. The four genera are certainlv nearly related to each other, and as their starting point 1 think we may take Histoderma as most probable, which shows the least deviating structures; as the genus nearest related to this I take Inflatella, which, especially in the skeletal structure, presents the greatest accordance, and on the whole mainly differs only in the want of microscleres , a difference which, when the other structures agree, is of very slight consequence, indeed even the right of Inflatella as a separate genus is perhaps doubtful, but at present 1 think, there is some reason to keep it. Also Histodermella must be nearly related to Histoderma, one species, lugolji, shows both in its exterior and in the skeletal structure great agreement; the curious, spined spi- cules which are present in this genus, are somewhat surprising, but I think they must probably In- taken to have their origin from original special skeleton spicules. Cornulum stands a little more apart, distinguished by its palmate chela.-. — I thus take these four genera to be nearly related and to represent a type of Myxilleae in which the original skeleton spicules have disappeared. As said. Histoderma might be thought to form the starting point; the genus outside the group, nearest related to Histoderma, is perhaps Hymedesmia (= Leptosia Tops.); in several species of this genus we find a strong dermal skeleton formed of diactinal spicules, and at the same time tin- inner skeleton, consisting of the basal acauthostyles, may be very little developed; the acanthostyles may be present in so .-mall numbers, that great care is necessary to avoid mistakes, just in Hymedesmia-species of this latter structure we find at the same time a strongly developed dermal skeleton which also has well developed fibres going from the dermal membrane inwards, and here consisting of the same diactinal spicules which form the dermal skeleton itself. Finally such species may have long, tubular papillae (e.g. Hymedesmia filifera O. Schmidt, and several other species). — It is perhaps a question whether Histoderma plilx. nodes Cart, will not prove to be a Hymedesmia. -- When now such species get quite roundish and grow without attachment, as e. g. //. appendiculatum , the elimination of the acanthostyles is easily understood, and the transition to the freely growing species is formed by such attached species a- foi instance Histoderma physa. The genus Melonanchora seems to me to form a beautiful and interesting instance of the opinions here advanced; one species oi this genus has the spiculatiou and skeletal structure typical for the Myxilleae, with skeletal styles and diactinal dermal spicules; these latter, however, form a very dense dermal skeleton, and the species has oscular and pore-papillae; the othei species of the genus has a similar construction, but tin skeleton spicules have disap] and the whole skeleton is formed of dermal spicules. 2g PORIFERA. III. Finally 1 may direct attention to the fact, that I have in the present work placed the genus Hymedesmia in the subfamily Ectyoninae, which perhaps might seem to go against the views given above about the relationship of this genns to the gronp treated here; yet this is not so, since firstly, the subfamilies Mycalinae and Ectyoninae, as I have already mentioned earlier, are scarcely quite natural, and even if so it was not impossible, that genera, which on account of their characters must now be placed in the Mycalinae, should be thought to have originally been derived from Ectyonine forms. In the first part of this work I broke up Carter's Phloeodicfyinae and placed its two genera Phloeodictyon and Oceanapia in the Renierinae and Gelliinae respectively. In a work published in 1905 (Rep. of the Pearl Oyster Fisheries of the Gulf of Manaar, Part III, 165) Dendy keeps the subfamily Phloeodictyinac under the family Desmacidonidae, and he refers to it the genera Phloeodictyon, Oceana- pia. Histoderma, Sideroderma and An/pliiasfrel/a. His reasons for keeping these forms together are mainly the same as those of Carter on founding the group, viz. the hard dermal layer and the presence of fistula;, but on account of the chelte in Histoderma Dendy now removes the group to the Desmacidonidae. In Part I of this work pag. 56—57 I gave the reasons which seemed to me to necessitate the breaking up of the Phloeodictyinac, and the same reasons are still valid. While Dendy thus lays stress on the outer shape and the presence of a solid dermal layer as the distinguishing characters, but pays no attention to the spicules, I on the contrary follow the opposite way and take first, as the most important character, the spicules and what may be deduced from them with regard to the relationship of the forms. Dendy would also have difficulties in delimiting his subfamily; Phloeodictyon and Petrosia are, as I have already declared (Part I, 1. c.|, nearly related; Thiele says (Zoologica XXIV, 2, 1899, 19) that Phloeodictyon (Rhizochalina) medium is an intermediate form; Melonanchora, which has a solid dermal layer and papillae should, I think, also be referred to the Phloeodictyinae and the same holds good with regard to several Hymcdcsmia-species; also some species of Gellius should be placed here according to the views of Dendy. On the other hand, I think that the spicules give good hints towards a natural grouping; the oxea present in Phloeodictyon are spicules typical for the Homorrhapidae ; Oceanapia and the species of Gellius, which are provided with a solid dermal layer, have oxea of quite the same kind, and these together with their microscleres refer them to the Heterorrhaphidae. The facts are quite otherwise with regard to the spicules in the four genera in question; their spicules are diactinal (when fully developed), but of quite another type from those occurring in the Homorrhaphidae and Heterorrhaphidae. That this is the case is shown, and beyond doubt,- by the development, since while the spicules in Homorrhaphidae and Heterorrhaphidae are really diactinal, and also originate in this form, the spicules in the four genera mentioned are on the contrary only secondary diactinal, but originate as monactinal; they have thus a development quite as the dermal spicules in other Myxilleae, as I have described in Part II of this work, pag. 125. I therefore take it to be quite certain, that these genera belong to the Myxilleae. and that their spicules answer to the dermal spicules in the more typical Myxilleae. but here form the whole skeleton, of which the interior skeleton however is generally weak. The facts present in Melonanchora emphysema seem to me in the highest degree to confirm this view. The occurrence of chelae also shows that these genera have nothing to do with Phloeodictyon or Oceanapia : that the chelae may sometimes PORIFERA. III. 2g disappear does not invalidate the value of this character. Dendy has also in his subfamily Phi dictyinae the genus Amp hias tr ella with the species birotulifera Cart.; this species has birotulae for micro- scleres and otherwise a structure almost the same as a Histoderma -- it shows especially a striking resemblance, both in outer shape and in structure, to f/istodermella coriacea — ; this species certainl) belongs to lotrocliota. but is a species in which only the dermal spicules arc present, and if we form a special genus for it, this genus must be placed near to Iotrochota. After the manner in which I understand the classification of the above-mentioned forms, we will thus in the various families find the phenomenon, that certain forms have a specially developed dermal skeleton, as a rule together with a reduction of the inner skeleton and occurrence of longer or shorter papillae, by which these forms, in spite of their belonging to different families, get a certain mutual resemblance. It is then an obvious conclusion, that a common factor must he of influence. but it seems not possible in our present state of knowledge to point out such a factor. It is easy enough to understand that all these sponges get provided with papillae, since the hard dermal layer, furnished with close-lying spicules is not adapted to be pierced by pores and oscula and there must therefore be special contrivances for these, viz. the fistulae or appendages, and somewhat similar reasons hold good with regard to the reduction of the inner skeleton. But the cause of the development of the hard dermal layer is therefore not explained, and the only thing, that can he said, is that it seems to be in some connection with the fact, that these forms show a tendency to get free, without attach- ment, or at all events without attachment by a fast-grown basis. The forms which are attached, either with a broad base as Histoderma physa, or by a peduncle as two of the In/tatella-species, have no specially strong dermal laver; in the quite free forms as most Phloeodiclyon-S'pecics, Oceanapia, f/isto- dermella, especially coriacea, and Amphiastrella, the dermal layer on the contrary gets very strong and solid. Grayella Cart. ( Yvesia Topsent, 1892) Tin- external shape varying from thinner or thicker incrustations through massive or cushion- shaped forms to more or less erect and finally quite erect, club-shaped, stalked ami sometimes branched forms. The skeleton consisting of, of/en rattier thick but loose, fibres, formed of smooth spicules: in the iucrustiii!> and massive forms the fibres radial,- from the base upwards and outwards, in the erect there is formed a central axis from which fibres radiate to the surface. The dermal skeleton consisting tangential, generally -eery close-lying, spined spicules, making the dermal membrane very arm. Spongin present or wanting. Spicula: megasclera; the skeletal spicules are smooth, tiny are most frequently iliac final, lor no/a. strongyla or tylota, but liny may be mouac/iual. styli: the dermal spicules are spiued. monactinal or diac/iual. Microsclera are chefe arcuafe. to which may be added sigmata; sometimes ngmata are found solely, and microsclera may be quite absent. PORIFKRA. III. r. G. pyrula Cart. PI. II, Figs. 15—19, PI. V, Fig. 2. metella pyrula Carter, Ann. Mag. Nat. Hist. 4, XVIII, 388, PL XIV, fig. 20, PI. XV, fig. 38. 1885. Sclerilla arctica Armauer Hansen, The Norwegian North Atl. Exp. XIII, Spongiadae, 12, PI. II, fig. 4, PI. IV, fig. 15. 1885. Sclerilla dura Armaner Hansen, ibid. 13, PL II, fig. 5. 1892. Yvesia pedunculated Topsent, Resultats des camp. sc. du Prince de Monaco, Fasc. II, 105, PL V, fig. 6, PLX, fig. .7. 1903. Yvesia lobata Arnesen, Bergens Mns. Aarb. 18, Taf. II, Fig. 7, Taf. V, Fig. 1, Taf. VI, Fig. 2. 1904. Yvesia pertusa Topsent (11011 pertusa Tops. 1892), 1. c. Fasc. XXV, 196, PL XV, fig. 20. 1909. Grayella pyrula, Lmidbeck, Meddel. 0111 Gronlaud, XXIX, 443. Erect, club-shaped, generally with a shorter or longer peduncle, above sometimes divided into a couple of branches, or somewhat lobate; sometimes it may be compressed. Surface smooth, densely beset ■with smalt, round or oval, more or less distinct pore-areas ; the dermal membrane is stretched over the pore-arkas as a thin membrane, between these it is not sharply marked, resting on the ends of the fibres of the main skeleton. The pores are found in the pore-areas ; oscula spout-shaped, present in varying numbers on the upper part, or scattered. The dermal skeleton formed of close-lying, tangential acantho- stvli: the pore-areas have only chela. J'he main skeleton consisting of a central axis from which fibres radiate to the surface more or less regularly; there are no transverse fibres, but between the fibres lie scattered acanthostyli. Spicula: megasclera ; the skeletal spicules smooth tornota o-jj/ — o-j6'""", the dermal spicules acanthostyli cmg — crig6""" ; microsclera chela areuahe cro2i — o-02$j""". Of this interesting species we have a somewhat considerable material of specimens of various sizes. The species is always erect and more or less distinctly club-shaped, and the deviations which may occur are easily traced back to the club-like shape. The small specimens are all regularly club- shaped with a shorter or longer peduncle; it is when the sponge grows larger that the shape may vary somewhat, thus the upper part of the body may be thicker or thinner in relation to the peduncle, the sponge may be high and slender or relatively short and thick, in the latter case it may be without any pronounced peduncle, only narrowed below; further it may be divided into a couple of branches in its upper part, or be more irregularly lobate, or finally it may instead of being round be rather strongly compressed. All previously described specimens are small, and they all have also a club- shaped exterior, only the specimen described by Armauer Hansen 1. c. is larger and shows the branched and compressed shape. One of the smallest of my specimens has a height of n""", the pe- duncle is r$mm thick and the upper part about 5""" thick; then we have specimens of all sizes up- wards, the largest has a height of 50""" of which the peduncle makes the half part; this latter, which is rather thin, has a diameter of about 2ram, and the upper part is about 10""" in thickness. The peduncle is slightly dilated below and shows here a surface of attachment, but most specimens are torn from the substratum, a single one sits on a fragment of a mussel-shell. The consistency is rather hard and somewhat elastic, but it may be different according to the degree of contraction; when the sponge is strongly contracted, as is often the case, the consistency gets very hard. The colour (in PORIFERA. III. ,r spirit) is whitish yellow, sometimes somewhat greyish. The surface lias, as commonlv in the genus Grayella, a very characteristic aspect, being denselj Inset with pore-areas. These areas are circular or generally oval and have a slightly elevated edge which surrounds the somewhat immersed pore- membrane. Such is the structure in the specimens which are least contracted, but as a rule the sponge is more highly contracted, and then the pore-areas become indistinct or are only seen as small tubercles, and when the sponge is very strongly contracted they nearly quite disappear, and at the same time the surface becomes rugose or wrinkled. For the rest the surface is all but smooth, the spicules not being projecting or only to a very slight degree. The dermal membrane is in the pore- areas a thin membrane, between the areas it is not sharply bounded inwards, and it is here richly provided with spicules. Pores and oscula: The pores lie in the mentioned pore-areas in a numbei of about ten or more in each area, they are circular or oval and were measured from quite small up 0-09""" in largest diameter; the pore-areas have a greatest size of 0-5""". The oscula are spout-shaped, as the opening is surrounded by a conical collar, supported by spicules. The number of oscula is various, in the small specimens there is most frequentlv only one osculum, which is then placed at the upper end, but in the larger specimens there are several oscula, in a single specimen even eight. The cni/iil system seems to be very lacunous; there are especially extended cavities somewhat below the surface, and they are extended somewhat parallel to the surface; they evidently belong to the excurrent svstem, as they are in direct connection with the oscula. If a piece of the skin is cut off, the openings of the incurrent canals, which are vertical to the surface, may be seen below the ] tore- areas by aid of the microscope. These structural features are tolerably observable, when the sponge is not too strongly contracted, but often the specimens are contracted to so high a degree, that these structures are quite indistinct, at the same time that the pore-areas on the surface are closed and dis- appearing. The sponge is evidentlv able to contract itself very strongly, and even the least contracted specimens in my material are certainly contracted to no slight degree; the structures seem to show that they are able to be considerably more distended, and the inner cavities, the pore-areas and the canals are in this state certainly considerably larger. The skeleton: The dermal skeleton consists of close-lying, tangential acanthostyles, which lie- in more than one laver; thev are only found in the membrane between the pore-areas, while the membrane of the pore-areas themselves is quite devoid of them; they do not form any real reticulation but by their arrangement around the pore-areas a kind of network is however formed. In the pore-mem- brane, as said, no acanthostyles are found, but here chelae occur in great numbers. The main skelt is of a dendritical structure; upwards through the peduncle and up towards the upper end of the sponge goes a spicula-axis, and from this fibres issue which go out to the surface and at the same time branch somewhat; outermost the) are spreading and support the dermal membrane, but do not project beyond the surface; as the outermost spicules in tlu- fibres do not go to the pore-areas, but only to the membrane between them, they become partly arranged circularly around the pore-areas, as may be seen, when a piece of the skin is cut off and examined from above. \ transverse section of the sponge shows the fibres radiating regularl) from the axis to the surface, between the fibres no connecting fibres are found, but some scattered spicules occur between them; these spicules are all acanthostyles, while the fibres are formed exclusively of tornotes. Downwards on the peduncle ,2 PORIFKRA. III. the layer of tissue outside on the axis is thin, but the skeleton is of the same construction, with radiating fibres. The skeleton in the wall of the oscular cones is formed of a dense layer of tornotes all parallel to the longitudinal direction of the cone; they are partly divided into bands or fibres; this skeleton is formed in such a way that the fibres going to the surface continue out in the oscular cones at the places, where oscula are found. On the outer side of the oscular cone there is found a layer of acanthostyles, and further there are many cheke in the wall. This structure of the oscular cone shows, that it is not formed of the dermal membrane solely. As a rule the spicular axis is very thick and strong, it is thus in one of the larger specimens zmm thick below in the peduncle, and above, at the upper end, o-6mi" thick. The skeleton is constructed in the described way in the specimens where it is regular, but a good deal of irregularity may occur, I think partly caused by the presence of the inner cavities. Between the ordinary fibres some very thick ones may occur, which present themselves as branchings of the axis; the fibres going towards the surface may be curved in different ways, as they bend round about the cavities, and they may bend round to such a degree, that they do not go upwards but downwards. Some of these irregularities are certainly due to the contraction, and I think the skeleton would show more regularity, if it was examined in a sponge in a quite distended condition. — Spougin is found in the spicular axis, especially below, towards the base, but the amount is only slight, and I could not observe any spongin outside the axis. Spicula: a. Megasclera; i. The skeletal spicules are tornota, they are straight or slightly, and then as a rule somewhat irregularly, curved, they are slightly fusiform and have somewhat short, sharply pointed ends; the length may vary a little in various individuals, it is 0-357— 0-58 mm, and the thickness may in all vary between 0-005 anc^ o-onmm, by far most frequently it lies between 0-007 an^ o-oo8mm. The tornotes sometimes show a quite slight tendency to become polytylote. The fully developed tornotes have quite equal ends, but quite fine developmental stages were observed, and these were styles; when they have grown a little older, they have still unequal ends, but they get equal-ended already at an early stage. 2. The dermal spicules must be termed acanthostyli, as one end is pointed, but the apex is short; sometimes, but rarely, the apex is indistinct or quite wanting, so that tin- spicules are near to, or are really strongyles. They are more or less curved, and it is worthy of note, that the curvature nearly always lies nearest to the rounded end; the spicules are distinctly fusiform. The spinulation is dense and coarse, the spines have a length of about half the diameter of the spicule. The spinulation may vary somewhat with regard to density and the size of the spines and this is in relation to the variation of the spicule in size, in such a way, that the larger the spicule' is the more densely it is generally spined, and the larger are the spines. To be sure these variations may generally be found in the same individual, but there may, however, be the difference between the individuals that in some the smaller, in others the larger spicules are by far the most numerous, in a single specimen the acanthostyles are on an average more diffusely spined than in the others. The length of the acanthostyles is 0-119— 0-196""" a"d the thickness in the middle, the spines not included, 0-005— 0-014""". A number of developmental forms in different stages were present, the finest of them being already distinctly and somewhat strongly spinulous; the developmental stages are all distinctly monactinal. As said above the tornotes form the fibres, while the acanthostyles form the dermal skeleton, but are also found in the interior of the body, especially between the fibres. PORIFERA. III. s 1). Microsclera; these are of one form, chelae arcuatse, they have a curved .shall, the Free middle part of which is more than one third of the length of the chela, the tooth is elliptical, ol ame length as the pointed lobe-shaped alse. The length is 0X>2] -0-0257 i llu' diameter of the .-.halt is 0-0028""". The chehe occur richly especially in the pore-areas and tin- oscular wall, but the} ilso otherwise found round about in the tissue. Embryos: In several specimens embryos were found round about in the tissue, and they are thus not only found innermost, close to the axis, as declared by Carter 1. c. They are globular or 1 of an average diameter of about 0-29 n"\ Most of the examined specimens contained no spicules, but some single were developed so far, that they contained spicules; these were dermal spicules, and thev quite resembled the developmental stages of the dermal spicules in the grown sponge. It is worthy of notice, that the first occurring spicules here are the spined dermal spicules, while elsewhere in the Myxilleac it is the skeletal spicules which occur first. Remarks: As I have examined preparations of Carter's type-specimen, the identification is certain. For the rest the description given by Carter is by far the best of all the descriptions published, as he describes the skeleton and the inner cavities in somewhat detail. The species is also rather well recognizable after his description, when the curious, diagrammatic way in which Carter made figures of the exterior, is borne in mind. The points on the surface which Carter mentions and figures, are. of course, the closed pore-areas; he mentions that they form low conical projections, which are formed of aeanthostyles "arranged in a whorl-like manner" and he figures this structure. Anything similar I have not found in my specimens, but I think, that by a certain degree of contraction the spicules around the pore-areas may very well present themselves in a way answering to Carter's expression. Armauer Hansen's type-specimens of Sclerilla arctica and dtira I have also examined, and they proved to be the present species; his figure of the aeanthostyles as oxea is erroneous. Arm; Hansen concludes with a remark whicli shows, that he has well seen the conformity of his two species, and the remark at the same time is very curious as he says: "Probably it would be more correct to assign them to one species". I have also examined the type-specimen of Arnesen's lobata. -- I also refer Topsent's )". pedunculata and the same authors )'. pcrtusa from [904 (but not 5". pertusa 1892) to the present species; the first named species has relatively small and somewhat diffusely spined aeanthostyles, but this is a character, whicli according to my observations may he !■ in G. pyrula, and otherwise the two species exactly conform. J '. pcrtusa Tops. [904 seems to 111 1 he quite the same as the present species, and I really do not understand, win Topsent refers it to his J", pcrtusa established in 1892, which latter has typical acanthoxea as dermal spicules. Locality: Station 4, 640 07' Lat. N., 11 vz' Long. W., depth 237 fathoms; station s, 63 56' Lat. N., 24° 40' Long. \\\, depth 136 fathoms; station 27, 64 54' Lat. N., 55 to' Long. W., depth 393 fathoms; station 57, 63" 37' Lat. N., 130 02' Long. YY., depth 3511 fathoms; station 85, 63 2I1 I. at. V. Loug.W., depth 170 fathoms; station 94, 640 56' Lat. N., 360 19' Long. W., depth 204 fathoms; station 95, 65 i| Lat. N., 300 39' Long. W., depth 752 fathoms; further it has been taken on 63 15' Lat. N.. 9 35' Loug.W., depth 270 fathoms and 61 23' Lat. N., 5 04'Long.W., depth 255 fathoms (Wandel), and East of the Faroe Islands, depth about [50 fathoms (Th. Mortensen). In all twelve specimens. The localitie situated in the Denmark Strait, between Iceland and the Faroe Islands and South of the Faroe Islands. The Ingolf-Expi '! n. \ I i .. PORIFERA. III. pt. dislr. The species is earlier known from the following localities: 65 miles North North- West of the Orkneys, depth 290 fathoms ("Porcupine"); 6i° 00' LatN., 40 49' Long. E., depth 200 fathoms, Vestfjord, depth 341 fathoms, 74° oS' Lat. N., 310 12'Long.E., depth 147 fathoms, (The Norwegian North Atlantic Exp.); in the Bergensfjord and at Trondhjein, depths 70 to 266 fathoms (Arnesen). If the interpretation of Topsent's two species is correct it has further been taken on 430 47' Lat. N., 90 27' Long. \V., depth 160 fathoms, 380 27' LatN., 280 03' Long. W., depth 277 fathoms and 370 57' Lat. N., 290 15' hong. \Y., depth 106 fathoms. According to these localities the species is distributed between - 1 and 38° Lat. N., and between 36° Long. W. and 310 Long. E. with a bathymetrical range from 70 to 752 fathoms. 2. G. gelida u. sp. PI. II, Fig. 20, PI. V, Fig 3. Erect, club-shaped and pedunculated. Surface smootli. densely beset zvilh more or less distinct pore-areas. The dermal membrane over the areas a thin membrane, supported by the ends of the fibres of the main skeleton Pores situated in the pore-areas, osculum spout-shaped, at the summit of the sponge. The dermal skeleton formed of close-lying, tangential acanthostrongyla. in the pore-membrane there are only chelm. The main skeleton consisting of a powerful median axis from which fibres radiate to the surface; there are no transverse fibres, but between the fibres lie acanthostrongyla. Spicule/: megasclera ; the skeletal spicules smootli toruota, more or less polylylote. o'40 — o-^jmm, the dermal spicules acantho- strongyla ten — o'/p"""; mierosclera cliche arcuata vojj — 0-028""". This species, of which we have only one specimen, has an outer shape almost like the preceding; it is erect and slender club-shaped, the lower part forms a peduncle which is broken below. The thickened part of the body is bent rectangularly above, but this is certainly only due to con- traction. The length of the sponge, when straightened out, is 50""" of which the peduncle has i8mm ; the thickness is above "mm. The consistency is hard, and the sponge is evidently highly contracted. The colour (in spirit) is whitish yellow. The surface is in most places beset with warts or knobs, as the pore-areas, on account of the strong contraction, are closed and form in this state only small protuberances; only in a few places they are open and show here the ordinary, characteristic appearance. There are no projecting spicules. The dermal membrane is a thin membrane over the pore-areas, and between the areas it is richly provided with spicules. Pores and oscula: With regard to pores and oscula quite the same holds good, as was said about the preceding species. The pores lie in a similar way in the sieve-like pore-membranes on the pore-areas; they had a diameter of up to o-o6n,m. Of oscula only one is found on the specimen, it forms a somewhat high collar just at the top of the sponge. The skeleton. This is also constructed quite as in the preceding species. The dermal skeleton ists of close-lying, tangential acanthostrongyla, they seem mainly lying only in one layer; they are not present in the pore-membrane, but here chelse are found. The main skeleton consists of a power- ful axis and of fibres radiating out from it, which are divided outwards towards the surface and support the dermis; the outermost spicules in the fibres meet the dermis especially along the edges of the pore-areas; connecting fibres are not found, but acanthostrongyla are lying between the fibres; PORIFERA. III. the fibres are formed of the smooth tornota. The skeleton in the oscular cone is formed of parallel tornota, outwards it has acanthostrongyla. In the axis a distinctly observable amount of spougin is found. Spicula: a. Megasclera; i. The skeletal spicules are tornota, they are straight and slightlj fusiform and slightly, but rather distinctly polytylote or show at all events an uneven contour; the ends are rather short and somewhat stubby. The length is 0*40 — 0-53 ' , and the thickness is 0-007 — o-oii""1'. 2. The dermal spicules are acanthostrongyla, thev are slightly curved or some- times straight and of the same or nearly the same thickness in the whole length; the spinulation is dense and coarse, and the spines are generally longer than half the diameter of the spicule; the spines are placed a little more densely at each end. The length is o-n — 0-19""", and the thickness 0*005 — °'(" Whether these spicules are really and primarily diactinal, I have not been able to decide, as no young developmental stages occurred; the shape of the spicule dues not point towards a monactinal origin, as also the few older developmental stages, I have seen, are quite diactinal; also the curvature, which is not localized at one end, but nearly always goes evenly from the middle towards both ends, points towards a real diactinal spicule, as also does the fact, that the spines on both halves are somewhat recurved towards the middle, while those standing in the middle are directed straight out On the other hand the dermal spicules occurring in the embryos are monactinal (see below under Embryos.) b.Microsclera; these are of one form, chelse areuatse; they have an evenly curved shaft, lobe-shaped, somewhat pointed ake and a pointed elliptical tootli of the same length as the alse. The length of the chelae is 0-024— 0-028 mm, and the thickness of the shaft is o-oo2i— 0*0028 The chelse occur numerously in the pore-membranes and the oscular wall, but also otherwise round about in the tissue. Embryos: Also in this species embryos were found round about in the tissue in great numbers; they are globular, of a diameter of about 0-29""". They were found both with and without spicules. The spicules are either only chelse or chelae and dermal spicules; the chelae seem thus here to be the first occurring spicules, and next the dermal spicules; in single cases only developmental stages oi chela were found and some few, thin developmental stages of dermal spicules. The dermal spicules were not, as is elsewhere generally the case, fine developmental stages, but on the contrary with regard to shape fully developed spicules; they were, however, smaller than in the grown sponge, viz. 0085 these spicules and the developmental stages were monactinal with one end pointed. This species is, as seen from the description, very nearly related to G. pyrula; the outer shape and the skeletal structures are the same, only in the spicules is a difference present, but this differ- ence is constant; the differential character lies in the dermal spicules, these being in gclida alw diactinal and of the same thickness in the whole length, and the) are on the whole characteristically different from the acanthostyli in pyrula; if the difference had only consisted therein that the pointed end here was rounded, no stress woidd have been laid upon this fact; furthei the tornota are distinctly polytylote and have stubb) ends, and finally the chelae are larger. To be sure 1 have oulj had one specimen of the species, but as this also shows a special condition with regard to loca being an inhabitant of the cold area, I have no doubt, that the species is certain and distinct. Locality: Station 116, 70° 05' Lat. N., 8 26' Long. W., South oi Jan Mayen, depth 37] fathoms (bottom temperature -:■ 0 | C). One specimen. 36 PORIFERA. III. 3. G. carnosa Tops. PL III, Figs. 20-21, PL V, Fig. 4. 1904. i vesta carnosa Topsent, Resultats des camp, scient. du Prince de Monaco, Fasc. XXV, 198, PL XV, fig. 19. Plate-shaped and incrusting, or higher and more massive. Surface rugose and wrinkled, without projecting spicules. Oscula spout-shaped. The dermal membrane a thin film. The dermal skeleton formed of acanthoxea which are very scattered and often only found in the dermis in very small number. 'The main skeleton consisting of fibres which from the base or the middle radiate toivards the surface; there are no transverse fibres, but the acanthoxea are scattered between the fibres. Spicula: megasclera ; the skeletal spicules are polytylote tornota, trjy—o-j/""", the dermal spicules acanthoxea a- 1 jy— o-ij4 CV007""". Some developmental stages were found, which were quite fine and more weakly spinulous. The toruotes form the fibres, the acanthoxea occur in the dermal membrane but much scattered, and besides they occur in the tissue, between the fibres. Microsclera are not present. I think it quite certain that this species is identical with carnosa Tops., as the description answers precisely; the outer shape, the skeleton and the spicules agree, only the spicules are declared to be a little larger, the toruotes 0-53 — 0'6omm with a thickness of 0^007— croio and the acanthoxea o-i6— o-i8mm with thickness 0-005 — 0"Oo6mm, but this difference is certainly of no consequence with regard to specific distinction; a fact which also contributes to the settlement that the species are identical is the communication by Topseut, that at the surface: "s'accumulent de large cellules spheruleuses a spherules dissociees, grosses, brillants . . . ", since my specimens show the tissue at the surface filled with densely crowded, curious, rather large, elliptical granules1). Locality: Station 9, 64° 18' Lat. N., 27° 00' Long. W., depth 295 fathoms; station 85, 63 21' Lat. V, 250 21' Long. W., depth 170 fathoms; station 89, 640 45' Lat. N., 27° 20' Long. W., depth 310 fathoms. The localities lie near to each other in the Denmark Strait. Gcogr. distr. The species has earlier been taken at the Azores at 38 46' Lat. X., 27 17'Long. W., depth 543 fathoms and 38° 35' Lat. N., 28° 06' Long. W., depth 664 fathoms (Topsent I.e.). I shall here try to give a list of the Grayella species in the consecutive order in which they have been described, at the same time noting their spiculation and outer shape: Spicules : skeletal. dermal. microsclera. shi 1862. G. rubiginosa O. Schmidt (Spong. d. adriat Meer. 72, Taf. VII, Fig. 5) (Myxilla) tylota styli crust. 1864. — albula Bow. (Mon. Brit. Spong. II, 253, III, PL XLV, figs. 21-241 ( //,///- chondria) styli styli chelse arcuatse crust 1869. — cyatophora Cart. (Ann. Mag. Nat. Hist. 4, IV, 190, PI. VII) strongylotornofa oxea massive 1870. — papulosa O. Schmidt (Gruudziige einer Spongienf. Atl. Meer. 57) f ( >/- brella) strongyla oxea chelae arcuatae tuberous. ') What these granules may he I cannot say; whether th, \ really have something t" <1" with Topseut's c< spherule-uses is, I think, doubtful. ,g PORIFERA. III. Spicules: skeletal. dermal. mierosclera. shape. 1876. G.pyrula Cart.(Ann. Mag. Nat. Hist. 4, XVIII, 388, PL X I V, fig. 20, PI. XV, fig. 38) (Cometella) tornota styli chelse arcuatse club-shaped. [882. — armigera Bow.'JfMon. Brit. Spong. IV, 73, PL IV, figs.io— 17) Hymenia- cidon) oxea styli chelse arcuatse crust. 1 885. - - dura Arm. Hans. (Norw. North. Atl. Exp. XIII, 13, PL II, fig. 5) (Sclerilla) oxea oxea chelae arcuatse club-shaped. - arctica Ann. Hans. (ibid. 12, PL II, Kg. 4, PL VI, fig. 15 (Sclerilla) . . . oxea oxea chelse arcuatse club-shaped. « — membranacea Ann. Hans.2 (ibid. 4, PL I, fig. 11, PLVI,fig.i2.) (Reniera) ? oxea ? ? 1892. — peduncuiata Tops. (Resultats des camp. sc. du Prince de Monaco, II, 105, PLV, fig.6, Pl.X, fig. 17.) (Yvesia). . tornota styli chelse arcuatse club-shaped. « — yrt//«^rTops.(ibid., 106, PL VI, fig. 13, PL X, fig. 14.) (Yvesia) tornota styli chelae arcuatse massive. « — Hauseni Tops, (ibid., 106, PL VI, fig. 9a, PL X, fig. 13) (Yvesia) tylota styli chelse arcuatse, crust. sigmata Richardi Tops, (ibid., 107, PL X, fig. 15.) ( ) "vesta) tylota styli chelse arcuatse, crust. sigmata — Guernei Tops, (ibid., 105, PL III, fig. 7, PL X, fig. 16) ( Yvesia) styli styli sigmata thick crust. « — Ridleyi Tops, (ibid., 107, PL X, fig. 12) f ) vesia) tylota with spi- tornostrongyla -f- crust. unions ends — pcrfnsa Tops, (ibid., 107, PL IV, fig. 10, PL X, fig. 18.) ( 1 rvesia) (nou per- iusa Tops. 1904) tornota oxea chelae arcuatse crust. « — linguifera Tops, (ibid., 108, PL X, figs. 10— n) (Yvesia) strongyla oxea chelse arcuatce massive crust - rosacea Tops. (Arch. Zool. exp. et gen. 2, X, XXIII) ( Yvesia) tornota styli chelse arcuatse thick crust. [898. - alecto Tops. (Mem. de la Soc. Zool. de Fr. XI 248, fig. 2 e— e")/ Yvesia) . strongyla oxea, with large -f- massive. spinulous spines and transform- ations to asters E903. /"/rw'/.v//,/Thiele (Arch, fur Natur- gesch. 1903, 391, Taf. XXI, Fig. 24 a — c) strongyla styli chelse arcuatse semiglobular. - mammillata Amesen (Berg. Mus. Aarb. 1903, 1 7, Taf. II, Fig. 6, Taf. VII, Fig. 2.) 1 Yvesia) tylota, styli to chelse arcuatse massive. single styli strongyla ■) Perhaps a CrelUt. -j This species might perhaps be a Crella, but the point cannot be decided, only the dermal mem- brane being known. PORIFERA. III. 39 Spi( ules: skeletal. dermal mien sh; 1903. G. lobata Aniesen (ibid. 18, Taf. II, Fig. 7,Taf.V, Fig. 1, Taf. VI, Fig. 2) (Yvesia) oxea styli chelae arcuatae club-shaped. 1904. — camosaTops. (I.e. Fasc.XXV, 198, PI. XV, fig. 19) / Yvesia) tornota, oxea -^ massive. polytylote — gelida mihi tornota, strongyla chelae arcuatae club-shaped. polytylote Of these species, four: G. arctica Ann. Hans., dura Ann. Hans., pcduncnlata Tups., and lobata Arnesen, disappear as identical with G. pyrula Cart, as shown above, (the shape of the spicules ol these species is in the above list given as recorded by the authors); the total number of the species belonging at present to Grayella is thus twenty, of which two, G. armigera Bow. and membranacca Arm. Hans, are doubtful. Cribrella hospitalis O. Schmidt (Grundziige einer Spongienf. des Atlant. Gebiet. 1870, 56, Taf. IV, Fig. 12) was by Topsent (1. c. 1S92, 103) taken to be an Yvesia, and I thought the same (The Danish Ingolf Exp. VI, 2, 1905, 127); Topsent had also good reasons for his interpretation, but yet it seems not to be correct, and there is every reason to take this species to be a Stylostichon, as I have de- clared more particularly (Meddel. om Gronland, XXIX, 1909, 447). Schmidt also says nothing about the arrangement of the oxea and the acanthostyli in this species, whereas he does so with regard to his next species C. papulosa, and I think it rather sure, that Fristedt's and Carter's hospitalis are identical witli Schmidt's species, and that the species is thus a Stylostichon; the figure by Carter (Ann. Mag. Nat. Hist. 4, XVIII, PL XIII, fig. i> be placed in the Erl I'll- tnerolf-Expcdition. \ I : PORIFERA. III. Leptolabis; below I have separated off the species with ancorse, forming for them my genus Hymen- ancora; though it is only a small number of species which are thus separated from Hymedesmia, the division is, however, of importance, making the remaining genus more uniform and natural. The possibility might also be suggested of dividing the remaining genus into two, containing respectively the species with and those without microscleres, but such a division I consider as not natural, as some species of both groups are nearly related; quite the same holds good with regard to the pos- sibility of separating off the species which possess sigmates, e. g. //. zetlandica Bow. with sigmates is nearly related to //. Bowerbanki n. sp., truncata n. sp. and latrunculioid.es n. sp. all without sigmates. i. H. Koehleri Tops. PL V, Fig. 5. [896. Leptosia Koehleri Topsent, Resultats scient. de la camp, du "Caudan", 284, PI. VIII, fig. 7—9. 1904. Topsent, Resultats des camp, scient. du Prince de Monaco, Fasc. XXV, 188. Ittcrusting ; oscula present as low and indistinct cones, with a dense skeleton of dermal spicules in Hie wall. Spicula: megasclera ; flic skeletal spicules acanthostyli with a somewhat distinct head, and spin ed in the rvliole or nearly the whole length, o-oq — o-jj""", not divided info frvo groups; dermal spi- cules polytylotc strongyla o-iq6 — o'jo""" ; microsclera chela: arcuatw 0'028 — o-ojo""". Of this species, which I refer to //. Koehleri Tops, (see below under remarks), we have a rather large material. The specimens form thin incrustations on stones, some single ones grow on tubes of Placostegus tridentatus The greatest extent to which my specimens reach is 24"""; the thickness reaches scarcely 0-5 mm. The colour (in spirit) is generally white, sometimes a little darker and then greyish brown or light brown. The surface is in the undamaged specimens smooth, without projecting spicules, but under a good lens it appears finely gritty, which is caused by the styles. The dermal membrane is an easily separable, thin and transparent membrane; it is filled with microscleres and is supported by scattered bundles of dermal spicules. Pores I have only observed with certainty in a couple of specimens, and in these they were seen as scattered, circular openings of a diameter of about 0-047 """! when the pores are normally open they probably lie in groups over the subdermal cavities. Oscula could in several specimens be observed with a good lens. They are scattered on the surface and appear as very weakly pronounced and low cones of a diameter of about imm. In the centre an opening appears which is larger or smaller in relation to the degree of opening of the osculum; on account of the slight thickness of the sponge the opening only appears as a deepening; when the osculum is closed, the cone appears slightly stellately corrugated. The dermal spicules form an oscular skeleton, as they lie very close in the wall of the oscular cone and are arranged subparallel, so that they radiate stellately towards the oscular opening; above the dermal spicules, however, lies the dense layer of cheke; this layer is only wanting just at the very summit of the oscular cone. Larger and smaller subdermal cavities or canals may be seen shining through the dermis, especially in the lighter coloured specimens. The skeleton. The dermal skeleton may be said for the greater part to be formed of the chelae, which form a very dense layer in the dermal membrane. Moreover, short and loose fibres or bundles PORIFERA. III. ^ of dermal spicules stretch, generally in a more or less oblique direction, from the interior of the sponge out to the dermis; besides, they are also found in the dermis, below the layer of chelae, as scattered bundles or single spicules; finally they form, as said, the skeleton of the oscular wall, also lying here below the layer of chelai. The main skeleton is formed of the acanthostyli which all have the heads fixed on the substratum and are vertical; the largest acanthostyli reach with the point up to the dermal membrane, but in the undamaged sponges they scarcely project beyond it. The smaller styles are placed between the larger. Spongin was not observed with certainty. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli which are generally straight, sometimes slightly curved; they have a somewhat distinct head, and from this they taper evenly, thus forming a long apex which is often a little more abruptly pointed at the very point. The spinulation is somewhat dense in the lower part of the spicule, but becomes more scattered out- wards, and the outermost part is generally smooth; the longer the spicules are the point is to a greater extent smooth, and in the smaller spicules the spines are found quite out to the point The spines are somewhat reclined. The head is densely covered with spines, which are considerably larger than the others, and also have a different shape; they are not reclined but more or less straight radiating, and they are as a rule not pointed but obtuse at the end; this obtuse or cut end is not rarely somewhat jagged or creuulated. The styles vary much in size and as the intermediate forms occur somewhat sparingly, the styles would seem divided into two groups with regard to size, but there is certainly no principal division into two groups. The length varies in all between oog and °'33mm> and the diameter at the head, including the spines, varies from 0-014 — 0-035 ""l!. With regard to the size of the styles there may be some difference in different individuals, in some the greatest length was thus 0-23""" and the diameter 0-024 """; when the spictdes thus only reach a smaller length, the mentioned division into two groups is generally still less distinct. 2. The dermal spicules are rather slender, straight strongyla; the two ends are often a little different, one being slightly thicker than the other, and sometimes one or both ends are slightly swollen; in other cases the ends arc somewhat narrowed. The strongyla are always polytylote with a row of swellings; this may lie more or less pronounced, but is rarelv or never quite wanting. The strongyla have a length of 0-196 0-31 and a diameter in the middle of 0-005— 0-007 ram. These spicules do not vary much in the various individuals, b. Microsclera ; these are chela; arcuatse; they have a more or less, but always rather strongly, curved shaft, the ala; are lobe-shaped, the tooth is narrowh elliptical with the end rounded, and there is a long, narrow tuberculum. The shaft is not cylindrical but somewhat flattened, which may be present to a higher or lower degree. The chelae may van a little in shape and size in the various individuals, the shape, however, is chiefly the same. The length is, all variations concerned. 0-028 — o-05omm; as instances of variation in size in various individuals I may note the following: 0-028 — 0-038""", 0-035— 0-042""", 0-037 — 0-045""" aI1(' 0-032- 0-050"""; the diameter of the shaft is 0*004 o-oio™"' in relation to the size of the chela, and to whether it is seen in front or side view. As said, the chelae occur in the dermal membrane forming a dense layer; the) are also seen singly through the whole body. Remarks: I have determined the above species as //. KochL n Tops., but not without hesitation. When Topscnt in [896 founded the species, he laid stress especially on tin polytylote strougyles, 44 PORIFERA. III. but this is not a very safe character, as strongyles more or less polytylote are of frequent occurrence in Hymedesmia; already when he founded the species, Topsent mentioned, that it varies somewhat with regard to the spicules, and in 1904 he again states that this variation takes place to a high degree, the three forms of spicules varying both in size and in shape; according to this I am not at all sure, that all the specimens mentioned by Topsent belong really to the same species. When I have determined my species as Koehleri, my reason is especially the somewhat robust, conical acantho- styli, generally with large, somewhat obtuse or creuulated spines at the head-swelling, the polytylote strongyla with unequal ends and also the shape of the chela;. Now, as already stated, my specimens may also vary to a certain degree, and the acanthostyli are not always so robust, or with so large spines at the base as in the more typical specimens, and the possibility, that there may be more than one, very nearly related species in my material is not quite excluded. Locality: Station 9, 640 18' Lat. N., 270 00' Long. W., depth 295 fathoms; station 16, 650 43' Lat. N., 36° 58' Long. W., depth 250 fathoms; station 54, 630 08' Lat. X., 150 40' Long. \V., depth 691 fathoms; station 57, 63° 37' Lat. N., 13° 02' Long. W., depth 350 fathoms; station 98, 65° 38' Lat. N., 260 27' Long. W., depth 138 fathoms; further it has been taken East and West of the Faroe Islands in depths of 250 and 180 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). The localities are situated in the Denmark Strait, between Iceland and the Faroe Islands and East of the latter. Geogr. distr. Topsent mentions the species from the Kay of Gascogne, depth 648 fathoms, and from the Azores in depths of 318 to 1350 fathoms. At present the species would thus be known from about 66° to 380 Lat. N., and between about 2° and 310 Long. W., with a bathymetrical range from 1 38 to 1350 fathoms. 2. H. lacera u. sp. PI. V, Fig. 6. Incrusting; surface smooth. Spicula: megasclera; the skeletal spicules slender acanthostyli with a slightly marked head, spiucd only in the lower half part, oij — crj/""". not divided into tzvo groups; dermal spicules large, generally slightly polytylote strongyla, 0'j2? — o-jj'""1 ; microsclera chela arcuatce "'"45 — o'054mm. < )f this species one specimen grows as an irregular incrustation on a worm-tube which is attached to a I lor 11 era lichenoides, another .specimen grows on a mussel-shell; the greatest extent of the specimens is about 15 ",m, and the thickness is about 0-5 mra or a little more. The colour (in spirit) is whitish grey or dirty brownish grey, but it is stated to be light dirty green in the fresh state. The surface is smooth, without projecting spicules. The dermal membrane is a somewhat solid film. The skeleton. The dermal skeleton is formed of bundles or short fibres, stretching from beneath up to the dermis, upwards they are somewhat peuicillately spread; moreover, bundles or somewhat longer fibres are found lying horizontally in the dermal membrane, and finally there are scattered chelae. The main skeleton is constructed in the ordinary way; the styli are very dispersed. So far as I could observe there is some spongin at the base. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli, which are very slender and straight or quite slightly, rarely a little more, curved; the head is generally only very slightly PORIFERA. III. swollen, and the shaft tapers into a long, fine apex. The spinulation is both in the large and in the smaller styli restricted to about the lower half part; in the small styli there are, however, generally some scattered spines more apically. The spines are only somewhat large on the head, outwards they become small and still further outwards they are small grits, but generally more or fewer larger spines are found between them. The spines are directed straight out, not reclined. The length is 0-13 — 0-51""", and the diameter of the head is 0-014 — 0-025 """■ The styli are not divided into two separate groups, but the intermediate sizes are rare. 2. The dermal spicules are rather large, straight strongyla; one end is generally a little thicker than the cither, but this feature is not always distinct; the thicker end, or both ends may be quite slightly swollen; the shaft is slightly polytylote, but sometimes this is hardly apparent. The length is 0-327 — 0-47""", and the diameter 0-007- "'"' ' b. Microsclera, these are chelae arcuatse; they have an evenly, not specially strongly curved shaft; the tooth is narrow, lanceolate, the ake are of the same length as the tooth, but thev are relatively narrow, they may therefore, in a certain view be of a somewhat claw-shaped appearance, and the chela may remind one somewhat of an ancora. The length is 0-045— 0-054""", tfle shaft is somewhat flattened, the diameter relatively from 0-0028 to 0-0057""". The chelae occur rather numerously scattered in the dermal membrane. The slender, often straight styli, generally showing some large spines among the small, are characteristic for this species together with the large dermal spicules and the large chelae with relatively long, narrow alae. ^Locality: Station 113, 69° 31' Lat. N., J° 06' Long. W., depth 1309 fathoms {bottom temperature -t-i°oC), one specimen; Forsblads Fjord in East-Greenland, 7.2 28' Lat. N., depth 50—90 fathoms (The Amdrup Expedition 1900), one specimen. The species must, according to these localities, be a native of the cold water. 3. H. storea n. sp. PI. V, Fig. 7. Incrusting; surface smooth'? Spicula: mcgasclera; the skeletal spicules- somewhat densely spincd acanthostyli with a globular head, the longer of them zvith a smooth apical part . o-io—o-jo""", divided into two groups; the dermal spicules polytylote strongyla 0-29— crjj"""; microsclera small chela arcuatce recalling in shape the palmate chela, O'ojj — crojti""". This species grows as extended but thin incrustations on stones; it reaches a greatest extent of 65""", the thickness is very slight, below 0-5"™. The colour (in spirit) is whitish grey. In the present state of the sponge the surface is densely and finely hispid, caused by the .skeletal spicules, but this seems to be due to the fact, that the dermal membrane is wanting for the greatest part; where the membrane is present, the surface seems to be smooth. The dermal mei membrane, resting on the skeleton below. The skeleton. The dermal skeleton ; tin dermal spicules form a skeleton of bundles and fibres stretching from the basal skeleton up to the dermis; the fibres run more or less obliqueh or bend horizontally under the membrane. The main skeleton is constructed in the ordinal \ way, consisting of vertical acanthostyli not placed speciallj densely. At the base an amount of spongin is present. 46 I'ORII'KRA. III. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli, they are straight, more rarelv slightly curved, with a distinct, globular, but however only slightly swollen head. The spiuu- lation is dense, consisting of large, more or less reclined spines; on the head, where the spines are largest, they radiate straight out, and also on the lowermost part of the shaft; the larger styli become dispersedly spined outwards and have a smooth apical part; the smaller ones are spined in the whole length, but they have often, however, the spines somewhat dispersed towards the apex. The length is crio— 0-30""", and the diameter of the head is 0-014— 0-028 n,m; the styli are not divided into two groups of size. 2. The dermal spicules are straight strongyla; they are of the same thickness in the whole length and more or less polytylote; one end may be quite slightly swollen. The length is 0-29 — 0-37""" and the diameter 0-005 — 0-007""". b. Microsclcra are chelce arcuata;, they are rather small and slender, the tooth is narrowly elliptical, the alas are connected with the shaft in their whole length, viewed from in front they are only slightly incised below, the chela thus approaches to the palmate chela;; the shaft is slender and evenly but not much curved. The length is 0-033— 0-038""", anc^ the diameter of the shaft 0-002'"'". The chela; occur in somewhat great numbers in the dermal membrane. This species in its acauthostyli somewhat resembles Koehleri, but it has larger strongyla, and more slender chela; of another shape; from baculifera Tops, it is distinguished by the chela;. Locality: Station 105, 650 34' Lat. N., 70 31' Long. W., depth 762 fathoms (bottom temperature -=- oc 8 C); station 125, 68° 08' Lat. N., 160 02' Long. W., depth 729 fathoms (bottom temperature -f- o° 8 C); the species is thus limited to the cold area. The localities lie North and North-east of Iceland. 4. H. lamina n. sp. PI. V, Fig. 8. Iucrustiug ; surface smooth. Spicula: megasclera ; the skeletal spicules acauthostyli with a rather small, globular head, spined in the whole length, but the spines in the longer spicules very dispersed tozvards tli, point. o-i2—o-jjmm, not divided into tzvo groups ; the dermal spicules strongyla, 0-22— o-j6"""; microsclcra small chela arcu"""- n°t divided into two groups: the dermal spicules strongyla o-jj <>■ ,,\v""".- microsclera chele a rata to' 0'02J — d the diameter of the shaft is 0-0028— o-oo4mm. The chelae occur rather numerously in the dermal membrane, and they seem exclusively or at all events chiefly confined to it. Locality: Station 25, 630 30' Lat. X., 540 25' Long. W., depth 582 fathoms; station 28, 65° 14' Lat. N., 55° 42' Long. W., depth 420 fathoms; station 83, 620 25' Lat. N., 28° 30' Long W., depth 912 fathoms; station 97, 650 28' Lat. N., 2 70 39' Long. W., depth 450 fathoms; further it has been taken at 640 42' Lat. N., 2 70 43' Long. W., depth 426 fathoms (Wandel), 620 29' Lat. N., 50 17' Long. W., depth 160 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902) and 630 05' Lat. N., 200 07' Long. W., depth 295 fathoms (The Fishery investigation steamer "Thor"). Nine specimens in all. The localities are situated in the Davis Strait, the Denmark Strait, South of Iceland and West of the Faroe Islands. 6. H. curvichela n. sp. PI. VI, Fig. 2. Incrusting; surface diffusely hispid. The main skeleton not dense. Spicula: megasclera; the skeletal spicules acanthostyli with no distinct or only o slight head; the small spined in the whole length, the larger less spined until only spined at tht base; the styli divided into two groups, large o-jj—o\S'o""", small u-inj — 1 r j o»"» ; the dermal spicules strongyla, slightly polytylote, erjj — 0-40"""; microsclera chela arcuatce, strongly curved, o-oji—o-oj?""". ( >! the specimens of this species one grows on a stone together with //. Koehleri, baculifera PORIFERA. Ill- aq Tops., dubia u. sp. (to be described hereafter), a Plocamia, an Eurypon and a Polymastia; another speci- men is sitting on a Pecten-shell, likewise covered with several other species, a third specimen grows on a Brachiopod-shell and finally a fourth on an erect Bryozoon. The species forms incrustations of a greatest extent of 25™"' with a thickness of about 0-5""". The colour (in spirit) is white or whitish, but with regard to two of the specimens it is stated, that they were dee]) blue in the living state. The surface is diffusely hispid from rather long projecting spicules. The dermal membrane is a thin and transparent film. Pores and osciila were not observed; some canals or canalicular cavities were seen to shine through the membrane. The skeleton. The dermal skeleton; in the dermal membrane there are numerous, but some- what scattered chela?. The dermal spicules form fibres or bundles stretching far down in the skeleton and seen quite down at the base; they stretch in an oblique direction up to the dermal membrane, and above, at the membrane the direction becomes nearly quite horizontal; some spicules are also King singly, quite horizontally in the membrane. Above, at the membrane the bundles are generally rather strong with numerous spicules. The main skeleton is of the typical construction and consists of basal acanthostyli with the head ends attached to the substratum, the longest styli pierce the dermal mem- brane and project beyond it. The skeleton is distinguished by the fact that the styli stand somewhat scattered, considerably more scattered than is commonly the case. At the base there is a distinct amount of spongin, in which the heads of the styli are imbedded; the spongin seems to form a con- tinuous lamella at the base of the sponge. Spicula: a. Megasclera. 1. The skeletal spicules are aeanthostyli which are straight or, especially the larger ones, slightly curved; they have generally no distinct head marked off, or this is only the case to a slight degree, but the dense spinulation at the base gives however the impression of a swelling; they taper evenly into a somewhat fine apex. The spinulation is as usual, the spines being largest at the head-end and radiating, while they are generally reclined on the shaft in the smaller styles. The smallest styles are spined in the whole length, the longer the styles are, the longer a part of the apex is smooth, in the longest styles only the lowermost part is spined, and the spines are here generally small, nearly gritty, and not reclined. The size of the styles varies greatly, the length from 0-107 to about o-8omm ' and the diameter of the head is from o-o 18— 0-034 ,ri. To be sure there is no principal difference between the styles, but there is a break in size between the longest and those coming next in length, such that the longest do not go below "-53" and the small not beyond o-Tf>mm. 2. The dermal spicules are rather long, straight, slightly polytylote strongyla; they have always one end thinner than the other; the length is 0-32 -0-40' , and the diameter in the middle is about 0-005— O'ooj """. b. Microsclcra ; these are eh eke arcuatse; they are distinguished by the shaft being strongly, nearly semieircularly curved; there may in this respect be sonu difference, the cheke may be both more or less curved, but the typical form is near the semicircular curvature; the end parts are relatively small, the tooth and the ake are short and rounded. The length is 0-031 — 0037 mm; the shaft is somewhat flattened and about elliptical in section, its di. nuclei i-, as seen from in front or from the side respectivel) 0-005 o-oio' . Tin chelae occur, as mentioned, numerously in the dermal membrane, but, however, somewhat scattered; they were not observed otherwise in the body. ») The greatest length cannot be given exactly, as tins, styles generally have tin- apes broken. I he [ngolf-Expedition. VI. 3. c0 PORIFERA. III. This chela bears, in its mostly curved forms, strange to say, great resemblance to the chela found in a species standing rather remote, viz. the chela figured by Carter (Ann. Mag. Nat. Hist. 5, XV, PI. IV, figs. 3 e, f.). Carter figures also a developmental stage (d), but considers this as an "ill- developed" spiculum. Locality: Station 15, 66° 18' Lat. N., 250 29' Long. W., depth 330 fathoms (bottom temperature -=-o°75C); station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; both these localities lie in the Denmark Strait; further it was taken East of the Faroe Islands, depth about 250 fathoms, and West of the Faroe Islands, depth 160 fathoms, (Ad. Jensen, the cruise of "M. Sars" 1902). Four speci- mens in all. It is curious that one of the localities, station 15, shows a negative bottom temperature, while the other localities are positive, but it is to be remarked, that this station lies just at the border between the cold and the warm areas. 7. H. rugosa n. sp. PL III, Fig. 1, PI. VI, Fig. 3. Incrusting ; surface somewhat wrinkled, smooth; oscitla present as very low cones, with a dense skeleton of dermal spicules in the wall. Spicula: megasclcra ; the skeletal spicules acanthostyli with a slight head, spiued in the whole length, divided into two groups, large o-jo — 0-420""", small 0-75 — o-/pmm; the dermal spicules polytylofe strongyla o-ji — 0-4/7"""; microsclera large clielce arcitata1 with the ends a little recurved, 0-052 — 0-064""". Of this species we have two specimens, one growing on a Brachiopod-shell, the other on a worm-tube. The sponge forms thin incrustations, which reach a greatest extent of 17 mm, with a thickness not exceeding 0-5 mm. The colour (in spirit) is yellow or light brownish. The surface is strongly wrinkled and rugose, the dermal membrane being folded, thus giving rise to the formation of irregular, sinuous furrows; this appearance is probably owing to contraction; for the rest the surface is smooth without projecting spicules. The dermal membrane is a somewhat solid, easily separable membrane, richly crowded with chelse. On one of the specimens two oscitla are seen; these have a structure similar to that of the oscula in H. Koelileri, they show in the centre a circular or oval impression, around which the dermal membrane forms stellately radiating folds; the dermal spicules form here a special skeleton, lying close together in the oscular wall with one end towards the opening, and from this radiating out in the membrane. The diameter of that part of the membrane which may be termed osculum is 1-5 — 2n,m. Pores were not to be seen in the membrane which is so densely charged with chehe. The skeleton. The dermal skeleton ; the dermal skeleton proper is formed of the chela; which are extremely close-lying in the membrane; when the)- are so close-lying, this is perhaps due to contraction. The dermal spicules partly contribute to the formation of the other skeleton of the sponge, as they form bundles or fibres, stretching from the very base up to the dermal membrane, generally in a very oblique direction; in many places they also form horizontal fibres just below the membrane; finally they form, as mentioned, the skeleton in the oscular wall. The fibres and bundles formed of the dermal spicules are rather thick. The main skeleton is of the typical construction, and PORIFERA. III. r. consists of vertical acanthostyli with their heads based on the substratum; the longest of them reach the dermal membrane, but do not pierce it. Just at the base of the sponge there is, I believe, a slight amount of spongin, but I was not able to see it with absolute certainty. Spicula: a. Megasclera; i. The skeletal spicules are straight or slightly curved acanthostyli; they have a slightly swollen head and taper evenly into a long apex which outermost is a little more abruptly pointed. The spines on the head are large, they are not pointed but truncate and not rarely somewhat hook-shaped. The spines on the shaft are somewhat dense and continue out to the point, but they are more scattered in the outermost part; the spines are reclined and compressed, so that they get the shape of a tooth of a saw. The styli vary greatly in size, and as intermediate forms are very scarce they are divided into two groups, which are, however, not quite sharply limited. The length lies in all between 0-15 and o\429mm, and the diameter of the head is 0-025- ""411 • When the single intermediate sizes are not considered the two sizes will be about 0*15 — 0*19 and 0-30 — o-429mm. 2. The dermal spicules are slender, straight, or more rarely slightly curved, polytylote strongyla, the ends are generally slightly swollen, so that the spicules approach to subtylota; one end is as a rule a little thicker than the other, and the thinner end has the largest swelling; the swellings are the more distinct the thinner the spicule is, in the thickest strongyla they are very slight or quite wanting. The strongyla vary somewhat in size, the length is between 0-31 and 0-417""", and the diameter is 0x505 — opoo8mm. b. Microsclera are chela; arcuatae; thev have a curved shaft and the ends are somewhat recurved; the tooth is lanceolate, with a long tuberculum, and the al:e are of the same length as the tooth; the shaft is somewhat flat, and nearly always slightly dilated in the middle The chela is rather large, and the size is somewhat constant, the length is 0-052— 0-064""", and the diameter of the shaft varies from about 0-005 — 0-011""" in relation to the chela being seen in front or in side view, and to the dilatation in the middle of the shaft being larger or smaller. Single develop- mental stages were seen. The chelae occur, as said, in enormous numbers and densely crowded in the dermal membrane, and they do not seem to occur otherwise in the body of the sponge. Locality: Station 9, 64° 18' Lat. N., 270 00' Long. W., depth 295 fathoms. Two specimens. The locality lies in the Denmark Strait. 8. H. splenium 11. sp. PI. VI, Fig. 4. Incrusting; surface hispid. Spun In: megasclera; flit- skeletal spicules densely and entirely spirted acanthostyli with a very slightly marked head, divided into two groups. / -nail O'op — (r/j"""; the dermal spicules strongyla o'2j — o-jimm ; microsclera cliche arcuatcc 0-041 o-ojj""". This species grows as rather extended incrustations on .1 somewhat large stone; it has a greatest extent of about i6mm, the thickness is small, below 0-5""". The colour (in Spirit) is whitish grew The surface is dispersedly hispid from projecting skeletal styles, and it seems to be so also when the dermal membrane is undamaged. The dermal membrane is a thin film, resting on the skeleton below. Here and there larger and smaller openings lor the canal system wen- observed, partly placed in groups; they are probably both pores and oscula, 7- 52 PORIFERA. III. The skeleton. The dermal skeleton; the dermal spicules form partly bundles, partly they are also seen lying scattered; they lie horizontally or stretch obliquely upwards between the ends of the skeletal styli, without any regularity; they lie horizontally especially just below the dermal membrane, and when the sponge is viewed from above, the spicules are seen lying irregularly below the membrane. The main skeleton consists of vertical, somewhat densely placed acanthostyli, the longest of which project beyond the surface. At the base a slight amount of spongin is found. Spicula: a. Megasclera. i. The skeletal spicules are straight acanthostyli; the head-end is only pronounced to a very slight degree, and the styli are therefore somewhat club-shaped. The spinulation is dense and is both in the small and the large forms continued quite to the point, or the spiues are at most a little more dispersed towards the point; the spines are directed downwards; they are distinct but not large. The length of the styli is 0-09— 0-27 mm and the diameter of the head 0-015 — 0-024 ram. Though the styli do not vary much in length in all, they afe divided however into two groups, the larger ones not going below o-23ram and the small not beyond o-i2",m. 2. The dermal spicules are straight strongyla, they are always a little thicker at one end than at the other, but they are otherwise of the same thickness in the whole length; sometimes they are very slightly poly- tylote. The length is 0-25— 0-31 mm and the diameter 0-005— 0-007 mm. b. Microsclera ; these are chela; arcuatfe; they are of ordinary shape, the shaft is evenly curved, the tooth elliptical, the alae lobe- shaped and broadly cut below. The length is 0-041— 0*047 mm an^ the diameter of the shaft is 0-003— 0-004 mm. The chelae occur numerously in the dermal membrane, but not, however, forming a layer. This species is somewhat related to H. storea, but it is characterised by the styli being more densely spined, and spined to the very point, and the spines are smaller; besides, the styli are divided into two groups; the chelae are of another] shape, and finally also the dermal spicules show a difference. Locality: Station 125, 68° 08' L,at. N., 160 02' Long. W., depth 729 fathoms (bottom temperature ■fO°8C); the locality lies North of Iceland. 9. H. tenuicula 11. sp. PL VI, Fig. 5. Intrusting ; surface somewhat hispid. Spicula: megasclera; the skeletal spicules acanthostyli with a slightly swollen //end and divided into two groups, large, with the apical part slightly spined or smooth, 0-286— 0-47 """. small, spined in the whole length, 0-12 — o-/j"""; dermal spicules strongyla 0-238—0-31"""; microsclera cliche arcuatee 0-032 — 0-037""". Of this species we have four specimens growing as thin incrustations on a Hamacantha impli- cate, on a Brachiopod-shell, on a tube of Placostegus tridentatus and finally on a stone, bearing a specimen of Petrosia crassa ; the largest specimen grows on the Brachiopod-shell, and it reaches the same extent as this, viz. 25 mm, but for the rest it grows on both sides of the shell which it thus quite covers. The spouge is very thin, scarcely reaching more than 0-25 mni in thickness; this is, as will be seen below, less than the length of the largest styli, which consequently project beyond the surface. The colour (in spirit) is slightly yellowish. The surface is distinctly hispid on account of the projecting of the longest styli. The dermal membrane may be traced as a thin film, supported by the dermal spicules. Pores and oscula were not to be seen. PORIFERA. III. 53 The skeleton. The dermal skeleton consists partly of bundles of dermal spicules which stretch up to the membrane from the skeleton below, partly and chiefly of spicules lying horizontally in the membrane; the latter spicules are partly scattered, partly collected into bundles or short fibres. The main skeleton is formed of vertical acanthostyli, the shorter of which reach to the surface, while the longer project through it. At the base of the acanthostyli there is found an amount of spongin, but it is difficult to observe. Spicula: a. Megasclcra. i. The skeletal spicules are acanthostyli, they have the head-end slightly swollen and taper from here into a long apex. The styli are divided into two sizes which are to be sure not connected by transitional forms, but do not show, however, any principal difference- in shape. The larger styli are straight or slightly curved; they have a densely spined head, the spines are here not pointed, but truncate or irregularly cut at the apex; on the lower part of the shaft the spines are still somewhat dense, but they are small, outwards they become mure scattered, and the outermost part is smooth or has only some single spines; the spines on the shaft are reclined. The small styli are likewise straight or very slightly curved, they are spined in the whole length, and the spines are reclined; the head is most densely spined. The length of the large styli is c/286 — o-47mm with a diameter at the head of 0-028 mm; the greatest length is only rarely seen; the small styli are o-i2— o-i5mm long and o-oao""11 thick at the head. 2. The dermal spicules are straight strougyla, one end is a little thinner than the other, and this thinner end is often slightly swollen; the length is 0-238 — 0-31""" and the diameter about oxxxi.""". b. Microsclera; these are chelae arcuatse; they have an evenly curved shaft, an elliptical tooth and lobe-shaped alae of the same length as the tooth; the free middle part of the shaft is not much more than the third part of the total length of the chelae. The length is 0-032 — 0-03 7™ "\ and the diameter of the shaft is about 0-004 """• The cliche are- found in the dermal membrane, generally they are scattered, sometimes King more densely. This species is distingushed from //. storea by its more slightly spinulous acanthostyli which are divided into two groups, and by a different shape of the chelae. Locality: Station 1, 620 30' Lat. N., 8° 21' Long. W., depth 132 fathoms; station 35, 65 t6' Lat. N., 550 05' Long. W., depth 362 fathoms; station 98, 650 38' Lat. N., 260 27' Long. \V., depth 138 fathoms; ami East of the Faroe Islands, depth 250 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). The localities are situated in the Davis Strait, the Denmark Strait and East and West of the Faroe Islands. 10. H. similis n. sp. PI. VI, Fig. 6. Incrusting; surface smooth. Spicula: megasclcra; the skeletal spicules acanthostyli with a small hut distinct //cm/. Ilic spinulation slight, the larger styli smooth in a long apical part, the styli divided into two groups, large 0-41— 0-65""*, small o-r^p — 0-2 38'"'"; the dermal spicules strongyla <>v microsclera strongly curved chelce arcuate- o'Oj ,- — o'Ojf""". This species forms small incrustations cm shells of Brachiopods, mussels ami Gasteropods, and on small stones; one specimen grows on a dead Oculina and another on a specimen of fotrochota -i PORIFKRA. III. oxeata; the greatest extent to which it reaches is i6mm. The colour (in spirit) is whitish to light yellowish. The surface seems, in the places where the sponge is undamaged, to be without projecting spicules. The dermal membrane is a thin film with close-lying chelae. The skeleton. The dermal skeleton ; the dermal spicules form fibres or bundles, which under various arrangements stretch more or less obliquely from the interior of the sponge out to the dermis; they may also be found in or below the membrane as horizontal bundles; the fibres may be of a considerable thickness; besides, the membrane has close-lying chelae. The main skeleton consists in the ordinary way of more or less vertical acanthostyli with their heads attached to the substratum; the styli are placed somewhat dispersedly. Spongin was not observed. Spicitla : a. Megasclera. i. The skeletal spicules are acanthostyli with a more or less marked, but small head and they taper into a long, fine apex; they are curved, and the curvature lies nearest to the head, it is found both in the large and small styli, for which latter it is especially characteristic. The spinulation is not strong; in the longer styli there are larger spines only on the head-end, the lower part of the shaft is grittily spinulous and the larger outer part, sometimes the whole shaft, is smooth; the smaller styli are a little more strongly spined and in the whole or nearly the whole length. The length is in all 0-149 — 065 n,m; the styli are rather distinctly divided into two groups, the large not going below 0-41 mm and the small not beyond 0-238"""; the diameter of the head is 0-014 — 0-025 mi". 2- The dermal spicules are straight strongyla, they are only very slightly thicker in the middle than towards the ends, one end is a little thicker than the other. The length is 0-298—0-35""" and the diameter is between 0-004 and 0-005""". b. Microsclcra ; these are chelae arcuatae; they have an evenly but strongly, up to nearly semicircularly curved shaft, the end-parts are relatively small, the alee lobe-shaped; the shaft is somewhat flattened. The length is 0-035— 0-044 "1:"> and the diameter of the shaft 0-004— o-on1"1" according as it is seen in profile or in front view. The chelae occur numerously in the dermal membrane and sparingly otherwise in the tissue. This species stands near to H. long/stylus n. sp. (to be described hereafter), but it is distingushed by the more strongly curved small styli and by other dermal spicules and chelae; it is also related to //. t urvichela, but also from this it is distinguished by the characteristic, curved small styli. The species must moreover be allied to H. (Hymeniacidon) paupertas Bow. but the small styli figured for this species, and also the figure of the chelae seem to prevent identification. Locality: Station 1, 620 30' Lat. N., 8° 21' Long. W., depth 132 fathoms; station 9, 640 18' Lat. N., 27° 00' Long. W., depth 295 fathoms; station 10, 64° 24' Lat. N., 28° 50' Long W., depth 788 fathoms; station 54, 630 08' Lat. N., 150 40' Long. W., depth 691 fathoms; station 85, 630 21' Lat. N., 250 21' Long. W., depth 170 fathoms; station 89, 640 45' Lat. N., 27° 20' Long. W., depth 310 fathoms; station 94, 640 56' Lat. N., 360 19' Long. W., depth 204 fathoms; station 98, 650 38' Lat. N., 26° 27' Long. W., depth 138 fathoms; further it has been taken at 630 12' Lat. N., 200 06' Long. W., depth 270 fathoms (The Fishery investigation steamer "Thor"); and East of the Faroe Islands, depth 250 fathoms (Ad. Jensen, the cruise (if "M. Sars" 1902); in all about nine specimens. The localities lie in the Denmark Strait, South of Iceland and East of the Faroe Islands. PORIFERA. III. 55 ii. H. nummulus n. sp. PL III, Fig. ii, PI. VI, Fig. 7. Incrusting; surface hispid? Spicula: megasclera; the skeletal spicules acanthostyli zvith no real lit mi. divided info two groups, large, only spined brlozv, o-j/ — O'pj""", small, entirely spined, o'i2 - o-/j""" ,- tin- dermal spicules strongyla, somewhat tending towards tornota, 0-35— 0-46"""; microsclera cliche arcuata, strongly curved with the ends somewhat recurved, 0^028 — o-o^j""". Two specimens of this species grow as small incrustations on stones, both of which are richly overgrown with several other sponges, a third specimen coats the broken base of a I font era sitting on a stone. The greatest extent reached is only 10""". The colour (in spirit) is white. Beyond the surface project the long styli, but whether this is so in the undamaged sponge I cannot say, as the surface is in nearly all places not intact. The dermal membrane is a thin film and seems to have no proper skeleton, but it is for the greater part wanting. Oscula and pores were not observed. The skeleton. The dermal skeleton ; the dermal spicules form bundles stretching more or less obliquely from the lower part of the sponge to the dermal membrane; the bundles are often rather thick. The main skeleton consists in the ordinary way of acanthostyli with their heads placed on the substratum; the long styli reach through the whole sponge; the small styli are by far the most numerous, so that each of the large styli is placed in a group of small ones. Spongin is found at the base of the styli. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli which are divided into two very distinct groups, large and small; the large styli have the base a little thickened but not forming a real head, from here the style tapers evenly to the point; the base bears distinct, but not large spines, outwards they soon nearly disappear so that about the lower half part is only slightly gritty, the rest is smooth; the styli are generally somewhat curved near the base. The small styli also have the head but little pronounced, but it is beset with somewhat large spines, and for the rest the style is spined in its whole length, with somewhat reclined spines. The length of the large styli is 0-51 — 0-95""" with a thickness at the base of 0-035— 0-040™'", the small styli are 0'I2— 0-14 " "" long and at the base about 0-021""" thick. 2. The dermal spicules are strongyla with some tendency towards tornota; they are straight and generally one end is a little more pointed than the other; they are of the same thickness in the whole length; their length is 035— 0-46""", and the diameter 0-005 o-oo8ram. Mil rose/era are cheke arcuatce; they have a strongly curved shaft, with the end-parts somewhat recurved, the ake are lobe-shaped and the tooth elliptical; the chelse \ai\ somewhat in size, the length is 0-028— 0-054 ml" and the diameter of the shaft is 0004— 0-006" The mentioned recurvation of the end-parts is very slight or quite disappears in the smallest chelse. This species bears some resemblance in spiculation to //. rugosa, but it has larger and much smoother styli, smaller eheke of a different shape, and the strongyla are not polytylote; it is also allied to //. stylata n. sp. (to be described hereafter), but differs by the longer and thicker acanthostyli, and a different shape of the chelae which in rtylata have the end-parts not recurved. Locality: Station 85, 63' 21' Pat. X., 25 2i' Long. \\\, depth 170 fathoms; station 89, 64 ).-,' Pat. N., 27' 20' Long. W., depth 310 fathoms; and at 65 v »' l.at. X., .:<> 53' Long. \\\. depth 56 PORIFERA. III. 208 fathoms (The Fishery investigation steamer "Thor"). The localities are in the Den- mark Strait. 12. H. dubia n. sp. PI. VI, Fig. 8. Incrusting ; surface finely hispid. Spicula: megasclera; the skeletal spicules acanthostyli with a small head, divided into tzvo groups, large, only spined below, o'jj — o-j8""". small, entirely spiued. crio — o-2j"""; the dermal spicules strongyla 0-26 — o'j2""" ; microsclera chela arcuate 0-040 — be some diffen in their structure; some of them are relatively pointed and have an opening above, while most of them are broader above and have here a prominent edge, but inside this are closed by a membrane; in this membrane I have not observed pores, but probably they are closed; in both cases there are large, hollow spaces below the papillae. The skeleton. The dermal skeleton; as the skeleton formed of the acanthostyli is quite in- considerable, it is the skeleton consisting of the dermal spicules which forms by far the greatest part of the whole skeleton; it consists of fibres which stretch quite from the base of the sponge upwards and stipport the dermal membrane; the fibres run more or less vertical, outermost, at the surface, the spicules are somewhat penicillately spread, or the fibres bend off below the membrane and run under it as horizontal fibres. The fibres may have a rather variable thickness, but they are always relatively thick and consist of many spicules; the thickness was e. g. measured to 006— 024 Under their course outwards the fibres may be more or less branched. In the wall of the papillae the dermal spicules form a dense skeleton, lying parallel with one end towards the edge of the papilla and here they are somewhat projecting. The dermal membrane itself is densely charged with chelce, forming a dense layer. The main skeleton consists as commonly of acanthostyli with their head-ends attached to the substratum; the skeleton is much dispersed as there is only found a bundle of styles in each place where the fibres, formed of the dermal spicules, go down to the sub- stratum, the styli thus forming the lowermost part of these fibres, just at the substratum. At the base a somewhat rich amount of spongin is found, in which the heads of the aeanthostyli are imbedded. Spicula: a. Megasclera. 1. The skeletal spicules are straight or, especially the larger ones, slightly curved acanthostyli; they taper into a long apex, which in the larger of them is a little more abruptly pointed outermost. The head may be somewhat various, it is generally not much swollen, but however somewhat pronounced on account of its spinulatiou. The spines are largest on the head: the larger styli are only spiued below, when they are shorter the spinulatiou goes further out. and the smallest styli are entirely spiued; in these latter the spines are rather large ami they are reclined, in the larger styli the spines are most often smaller and less distinctly reclined. The length varies much, from 0-095— 0-62 """, and the diameter of the head from 0-014 0-039""". A11 transitions in size are found, but the intermediate sizes are rare. 2. The dermal spicules are long, straight 01 very slightly curved strongyla which are of the same or about the same thickness in the whole length; one end is short and rounded, the other is a little longer, nearly truncately pointed, this latter end is generally slightly swollen, not so much however that the spicule max be termed ,1 tylostrongyle; \h>. swollen end corresponds to the original end of the spicule; sometimes both ends may be verj slightly swollen, the spicule thus approaching a tylotc; the strongyla may be quite slightly polytylote. The length 1 0-37 — 0-52""" and the diameter about 0-004- ( n"'s ''• (J'llU inonactiu.il developmental stages wen found, b. Microsclera; these are chelae arcuatae, they are of ordinary shape, with a regularly and evenly curved shaft, the tooth is elliptical and the ahe lobe-shaped, short and rounded, and of the 6o PORIKERA.. III. same length as the tooth. The length is 0-035— 0-044 """> tne shaft is flattened, its thickness is in relation to this 0-003 — 0-007 """. The ehelse occur through the whole sponge and in a dense layer in the dermal membrane. This species is somewhat characteristic, besides from its exterior, from the small acanthostyli being straight and slender and with large, distinctly reclined spines, and from the large strongyla; it is to be noted that it is not the smallest styli, but those a little longer which especially have large spines. The species is nearly related to the preceding H. stylata. but it is distinguished by the small acanthostyli with their large, reclined spines and distinct heads; also the strongyla are different, and the aire of the chelae are longer and more pointed in H. stylata. Locality: Station 54, 630 08' Lat. N., 150 40' Long. W., depth 691 fathoms; and at 640 42' Lat N., 27° 43' Long. W., depth 426 fathoms (Wandel). In all four specimens. The localities lie in the Den- mark Strait and south of Iceland. 15. H. procumbens n. sp. PL VII, Fig. 2. Tin rusting : surface slightly hispid. Spicula: mcgasclcra ; the skeletal spicules acanthostyli with a small head, spiued in the zoholc or nearly the whole length, the longer only very slightly spined out- wards, o'o8p — o-jjj""", not divided into two distinct groups ; the dermal spicules tornota u-2j — crjzy"""; mierosclera cliche arcuatw. often strongly curved, 0-024 — o-oj6'""". This species grows as small incrustations on pebbles, one specimen grows on the shell of an Area, and one on a dead Oculina; it has a greatest extent of about i2nim, and the thickness is exceedingly small. The colour (in spirit) is nearest whitish or whitish grey. The surface is very slightly hispid on account of the generally only to a slight degree projecting spicules. The dermal membrane is a thin film, supported by bundles of dermal spicules; it has somewhat densely lying cheke. The skeleton. The dermal skeleton consists of bundles of dermal spicules which are generally somewhat fan-like spread; the bundles stretch out to the surface, but they are for the greatest part strongly decumbent in the membrane. The main skeleton has the typical construction; it is rather dispersed, the single styli standing somewhat scattered. Spougin I could not observe. Spicula: a. Mcgasclcra. 1. The skeletal spicules are straight or nearly straight acanthostyli with the head-end most frequently rather weakly marked; the longest styli are often somewhat curved near the base; the spines are large on the head-end, but decrease rapidly outwards both with regard to size and to number, and the largest styli have thus the spines on the outer part much dispersed, and the spines are here weak. The small styli are entirely spined, and the spines are larger, but there does not seem to be sharply divided groups. The length is 0-089— °'35 mm an^ *-he diameter of the head is o-on — 0-027 mm. 2- The dermal spicules are tornota which are straight, or sometimes a little irregularly curved; one end is generally slightly thinner than the other; they are fusiform, being somewhat thicker in the middle, and some few are seen reaching a considerable thickness. The length varies much, from 0-23 — 0-327 "im, and the diameter is 0-004 — 0-0075 ",m. b. Mierosclera; these are PORIFERA. 111. ,,, chelae arcuatse; they have a more or less, sometimes very strongly, curved shaft, the end-parts are relatively small. The length is 0024 — 0-038"™, and the diameter of the shaft 0003— 0-005"" The chelae occur numerously and rather densely in the dermal membrane. This species may vary somewhat, especially with regard to the size and shape of the chelae; it is most characterised by the fusiform tornota, and this character in conjunction with the shape of the acanthostyli distinguishes the species with certainty. Locality: Station 54, 63° 08' Lat. N., 150 40'Iyong.W., depth 691 fathoms; station 98, 65 38'LatN., 260 27' Long. W., depth 138 fathoms. The localities are situated in the Denmark Strait and South of Iceland. 16. H. perforata 11. sp. PL HI, Fig. 4, PL VII, Fig. 3. Incrusiing ; surface somezvhat hispid; main skeleton rather dense. Spicula: megasclcra; the skeletal spicules acanthostyli with a very small or no head, entirely spined, or the longer with a smooth apical part, O'oSo—O'jj, not divided into two groups : the dermal spicules slender tornota cri?8 jj""": microsclera cliche arena tee, very varying in size, 0-021— 0-054""". This species grows chiefly on Brachiopods, as well on dead shells as on living specimens; we have in all sixteen specimens, thirteen of which grow on Brachiopods; the other three grow re- spectively on a Bryozoon, a worm-tube and a Peeteu-sheW. The greatest extent to which the species reaches is about i6mm, and the thickness is not beyond 0-5""". The colour (in spirit) is brownish yellow to dark greyish brown. The surface is hispid on account of the longer sty li projecting beyond it. The dermal membrane is a thin and transparent film. In the membrane larger and smaller, circular or oval openings are found, which are oscula and pores: they were measured of sizes from about 0-05 to o-3mm, but there seem to be all intermediate sizes, so that it is often not possible to decide whether we have to do with iucurrent or excurrent openings; the smaller openings, however, were most frequently collected in groups over the subdermal cavities, but the dermal membrane was much damaged and therefore the whole structure was not to be decided with certainty; probably there is the difference, that the pores form sieves while the oscula are larger, single openings. The somewhat close-lying, circular subdermal cavities or openings of the canals shine through the mem- brane, but they are only visible by the aid of a lens. The skeleton. The dermal skeleton; in the dermal membrane occur the chelae numerously, but somewhat scattered. The dermal spicules form bundles which stretch in an oblique direction from the skeleton out to the membrane; besides, both bundles and scattered spicules are found lying hori- zontally in the membrane. The main skeleton consists in the ordinan wa\ of acanthostyli which have their heads attached to the substratum; the longest of the styli pierce the membrane, the surface thus getting strongly hispid, but as the largest styli are not numerous, the sponge is somewhat dispersedly hispid; on the other hand the styli are in this species \er\ dense at tin- base, so that whether the sponge is seen in a vertical section, or the surface o! attachment is seen from below. the stvli are seen standing nearly head by head, only lure and there divided by the cavities of the 62 PORIFERA. III. canal system. At the base of the sponge there is found a somewhat rich amount of spongin in which the heads of the styli are imbedded. Spicula: a. Megasclera. I. The skeletal spicules are acanthostyli; they are straight or generally slightly curved; they have no head-swelling marked off or this is only weakly pronounced, and they taper evenly into a long, rather fine apex, and accordingly they are of a more or less club- like shape. The size varies to a high degree, and in relation to the size the spinulation also varies, but separate groups of size do not exist. The smaller the styli are the relatively stronger they are spined, and the spines are on the small styli continued out to the very point; the longer the styli, the longer a part of the apex remains smooth; in the large styli also the close-standing, some- what large spines on the head-end are relatively smaller than in the small styli, and the spines placed on the shaft are very small. The spines are in this species only slightly, or not at all reclined. The length varies from o-o8o — 0-53 rai", and the diameter at the head is about 0-011—0-031 n,m. 2- The dermal spicules are thin tornota; they are straight, of the same thickness in the whole length or quite slightly thicker in the middle; the points are typical toruote points, short and bounded by straight lines, and they are very sharply pointed. The fully developed tornota have the two points uniform or nearly uniform. The length is 0-178— o-22mra, and the diameter about 0-0028— 0*0040 n,m. b. Micro- sclera are chelae arcuatse; they have an evenly curved shaft, an elliptical tooth with a long tuberculum, and alae of the same length as the tooth. The size varies very much, the length from o-02i— 0*054 """ an*^ the diameter of the shaft is in relation to the size 0'0O2— 0-007 """• Some single developmental stages were seen. The chela; occur numerously in the dermal membrane, and are also seen singly lower down in the sponge. Locality: Station 4, 640 07' Lat. N., n° 12' Long. W., depth 237 fathoms; station 6, 630 43' Lat. N., 140 34' Long. W. , depth 90 fathoms; station 9, 640 18' Lat. N., 2 70 00' Long. W., depth 295 fathoms; station 16, 65° 43' Lat. N., 260 58' Long. W., depth 250 fathoms; station 27, 640 54' Lat N., 55° 10' Long. W., depth 393 fathoms; station 28, 65" 14' Lat. N., 550 42' Long. W., depth 420 fathoms; station 85, 630 21' Lat. N., 250 21' Long. W., depth 170 fathoms; further, it has been taken at 630 05' Lat. N., 22° 23' Long. W., depth 115 fathoms and 630 21' Lat. N., 160 22' Long. W., depth 296 fathoms. The localities lie in the Davis Strait, the Denmark Strait, South of Iceland and between Iceland and the Faroe Islands. 17. H. clavigera n. sp. PL III, Fig. 8 b, PI. VII, Fig. 4. Incrusting, thin; surface hispid. Spicula: megasclera; the skeletal spicules club-shaped acantho- styli, divided into two groups, both entirely spined, large 0-23 — o"2g8""", small a 095 — 0-12""" ; the dermal spicules tornota o-/6 — o-iylS""" ; microsclera chela- arcuaUe 0-041 — 0-032""". This species grows incrusting on a stone, which bears several other small sponges, and it grows quite close to a specimen of //. Bowerbanki n. sp. to be described hereafter; it has a greatest extent of 12 mm, and it is exceedingly thin and delicate. It is of a whitish colour (in spirit). The surface is very hispid on account of the erect styli being protruding. The dermal membrane is imperceptible and not separable, but it appears to be a very delicate membrane, richly provided, PORIFKRA. III. 63 however, with chelae. Oscula and pores were not seen, but the sponge is perforated by close-standing, vertical canals which shine through the dermal membrane and arc seen on the surface- as dark, round points; it would seem that the oscula are simple openings in the membrane, and the pores lie several together over the openings of the incurrent canals. The skeleton. The dermal skeleton consists of dermal spicules stretching from the skeleton below and out to the dermal membrane; it is very weakly developed and seems only to consist of single spicules, not forming bundles, and the spicules are not numerous. The main skeleten is formed in the ordinary way of erect acanthostvli with the head-ends based on the substratum, the longer of them protrude far beyond the surface; a very faint amount of spongin is present at the base. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli, and they are rather characteristic; though the basal end is the thickest part of the spicule there is however no head- swelling developed at all; from the basal end the spicule becomes only slightly thinner outwards. and the point is somewhat short; the spicule thus has a somewhat club-like shape; they are generally slightly curved. The styli are divided into two well defined groups, large and small. The large styli have a somewhat slight spinulatiou, only at the base there are some stronger, but however rather small spines, they are blunt and generally curved somewhat upwards towards the apex of the style; on the other part of the style the spines are small, but they are present to or near to the point, and the)- are reclined. The small styli have quite the same shape as the large, only they are generally not curved and the spines are relatively larger. The length of the large styli is 0-25 — 0-298""", with a thickness at the base of 0-021""", and of the small styli 0-095 — °'12 '""' with a thickness of about Q.Qj^mm. as js seen tne two groups are fairly distinct in size, and the variation in each group is onlj slight. 2. The dermal spicules are tornota; they are straight, rather thin and of equal thickness in the whole length; the points are short and sharp; the length is cri6-o-i7N , and the diametei o-oo2mm. b. Microsclera are chelae areuatae; they have an evenly curved shaft, the alse are lobe- shaped with the lower edge broad and straightly cut off, and the tooth is elliptical. The length is 0-041— 0-052 """ and the thickness of the shaft 0-005— 0-007""". The chelae are abundantly present in the dermal membrane. This species is nearly related to H. perforata, but it is distinguished by several characters; the main skeleton is less dense, the acanthostyli not being so densely crowded, the two distinct groups of acanthostyli are not present in perforata, and the acanthostyli are in the present species much less spined and in their whole length, while in perforata they are more strongl) spiued, but with the apical part smooth; also in the shape of the tornota and the chelae there are small differences, and finally the sizes of the spicules are different. Locality: The Denmark Strait, 650 50' Iyat N., 260 53' Long. W., depth 208 fathoms (The Fishery investigation steamer "Thor"). i.s. H. platychela 11. sp. PI. VII, Fig. 5. Incrusting; surface hispid. Spicula: megasclera; the skeletal spicules acanthostyli with a small head, somewhat strongly spined in the whole or nearly the whole length, ovj— oyj""", W divided into 64 PORIFERA. III. two groups : the dermal spicules tornota o-j2y—o-jj"""; microsclcra chela: arena fa- of a curious, broad and flat shape. 0-032 — o-ojj;""". Of this species we have one specimen, growing on a shell-fragment of &Pecten; the specimen tows on both sides of the shell having grown round the edge from one side to the other; the largest extent of the specimen is 15"'"', and the thickness abont 05 mm. The colour (in spirit) is brownish yellow. The surface is hispid from projecting dermal spicules. The dermal membrane is a thin film, but it is wanting to a great extent on the specimen. Oscula and pores were not observed. The skeleton. The dermal skeleton: the dermal spicules form bundles or fibres which stretch from the main skeleton, often from the lower part of this or quite from the base, in an oblique direction up to the surface, and project beyond this, and it is thus chiefly these spicules which cause the hispidity of the surface; outermost the spicules in the bundles are spread out somewhat fan-like. When the sponge is examined from above with a good lens, therefore, the fan-like bundles of dermal spicules are seen. In the membrane chelae are found, but the)' are very scattered. The main skeleton is of the typical construction, consisting of vertical acanthostyli with their heads fixed on the substratum; the longest of them project beyond the surface and contribute to the hispidity of the sponge. At the base spougin is found, but only to a very slight degree. S pic ida: a. Megasclera. 1. The skeletal spicules are acanthostyli; they are straight or somewhat curved; the head-end is a little swollen, and they taper evenly into a long, fine apex. The spiuulation is somewhat strong, the spines on the shaft are compressed and reclined downwards; the spines on the head-swelling are considerably longer, they are not compressed, and radiate straight out; these spines are truncate at the end and sometimes somewhat curved and hook-shaped, the small and intermediate styli are spined in their whole length, the longest styli, on the contrary, have a generally rather short part of the apex smooth. The styli vary much in size, but they are not divided into groups. The length is 0-13 — 0-45""", and the diameter of the head o-oi8— 0-035 mm. 2. The dermal spicules are long, straight tornota, they are slightly fusiform; the ends are short pointed, and the points are bounded by straight or concave lines. The fully developed tornota have equal ends, but the developmental stages are monactinal. The length is 0-327 — 0-53 mm, and the diameter in the middle about 0-005— 0-008 mm. b. Microsclcra ; these are chelae arcuatae; they are of a curious, short and flat shape; the shaft is slightly curved, and is not flattened; the alas are broad and lobe-shaped, and the tooth is rather broad and a little shorter than the alee. The angle between the axis and the tooth, and the curvature of the alse are such, that a transverse section of the chela through alae and tooth would form a transverse ellipse. For the rest the chelae are not rarely of a more or less irregular shape, and sour- monstrosities are also found. The length of the chelee is 0-032 — 0-035 n,m, and the diameter of the shaft about 0-004 mm. The chelae occur only in the dermis, but also here only in small numbers. Locality: Station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; the station lies in the Denmark Strait. 19. H. basispinosa n. sp. PL III, Fig. 5, PI. VII, Fig. 6. Incrusting; surface smooth, bearing some small, conical oscular cones with a dense skeleton of dermal spicules in the wall. Spicula: megasclera : the skeletal spicules acanthostyli with a small head. PORIFERA. III. divided into two groups, large, only spined at the base, 0-42— 0-59""", small, entirely spined, o-op—t the dermal spicules large tornota, o- 32— o- 50™"' ; microsclera small chela' arcuata-, resembling palmati chela, »■{) j ■,--- o'ojo""". The only specimen of this species forms an incrustation on a shell of a Brachiopod; it ha greatest extent of about 15"""; the thickness is 0-5 ir a little move. The colour (in spirit) is dark brownish. The surface is smooth or nearly so, without projecting spicules: it bears some conical papillce of a length of about imm; in the present state of the sponge the papillae are lying down to- wards the surface. The dermal membrane is thin, resting on the skeleton beneath and provided with some spicules, more or less scattered or bundle-like collected. Oscula and pores: the mentioned papilla- are oscular papillae with the oscular opening at their apex; the fibres of dermal spicules continue into the wall of the papillae and form here a dense skeleton of spicules lying parallel to the longitudinal axis of the papilla; pores were not observed with certainty; some few, small openings in the dermal membrane may perhaps be pores. The skeleton. The dermal skeleton. The skeleton formed of the dermal spicules consists of bundles or short fibres, which stretch from the lower part of the sponge up to the dermal membrane; the fibres are for the greatest part more or less horizontal; some single spicules or bundles lie in the membrane or just below it. The main skeleton is in the ordinary way constructed of perpendicular acanthostyli with the heads against the substratum; tliev are not close-standing but somewhat scattered. A very slight amount of spougin is present at the heads of the acanthostyli. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli; the\ are straight oi slightly curved near the base, and long pointed; the head is more or less pronounced, but generally only to a slight degree. The longer styli are onlv spined at the base, on the head and a little wax out; the small styli are entirely spined, but the spines become scattered towards the point; the spine- are small, only at the base some few spines a little larger may be found. The styli are divided into two distinctly separated groups, large and small; the large has a length of o-.ij— "•59"' and .1 diametei of the head of 0-021 — 0-025 """; the small styli are 0-09—0-23""" long, and the diametei of the head is 0-014— 0-021""". 2. The dermal spicules are rather large tornota, they are straight or nearh slightly tapering towards the ends and sometimes slightly polytylote; the points are short and sharp, sometimes the ends are a little swollen; the length is 0-32 .>■;,<>■■ and the diameter is o-oo| b. Microsclera; these are chelae arcuatae; they are small and slender, the shaft is only slighth curved, the tooth is elliptical; the ake are connected with the shaft lor about their whole length and the chela thus greatly resembles a palmate chela, or might perhaps even be termed so; the length of the chela is 0-025— 0-030""" an'l the thickness of the shaft 0-O02 The chelae are seen singly in the tissue, and they occur in rather great numbers in the dermal membrane, but they form no layer. This species is nearh related to //. platychela and has similar large dermal tornota. but i differs by the much less spined styli and the small ehehc, which ate quite different in shape, and finally also by the oscular papilla-. Locality: Station 2-S, the Davis Strait 65 1 |' l.at. X., 550 42' Long. W., depth 420 fathom-. One specimen. III. Ingolf-Expedil \ I ; POR1KERA. III. 20. H. longistylus 11. sp. PL VII, Fig. 7. Tncrusting; surface somewhat hispid. Spirit In: megasclera; the skeletal spicules acanthostyli with the titise thickened, but not tormina a real //end, the longer only spined at the base, the smaller in the whole length, the small styli are 0-119 — o-26""m long, with a diameter of the head of 0-020— 0-025 mm. Small individual variations in size may occur. Developmental stages of both sizes of the styli were seen in small numbers, showing that the two sizes are essentially different from the beginning. 2. The dermal spicules are tornota with intermediates to oxea; they are straight and long tapering; they vary a good deal in thickness, when they are thin they may be termed tornota, but often they are more fusiform and are then oxea; their length is 0-34 — 044 "'"■ with a thickness of o'oo8— 0-013 mm. Besides these spicules there are some stronger, especially thicker, and fusiform oxea of a length of 0-38 0-50""" and with a thickness in the middle of 0-017—0-028""". -- With regard to these latter spicules the facts are somewhat curious; they are mentioned both by Bowerbank and by Topseut, and both authors say, that they are present only in small numbers. But they seem to be subjected to great variations with regard to the number in which -they are present; generally they are only found in very small numbers, and such is the case in most of my specimens; but in one specimen they are very numerous; whether they are few or many the)- are always only present in the dermal membrane, and lying horizontally, but they are not found in the bundles which stretch down into the sponge; in the specimen mentioned, with numerous thick oxea, the horizontal spicules in the dermal membrane are almost all of this kind; as the skeleton in the wall of the papilla; is formed both of the spicules lying in the membrane itself, and of those belonging to the fibres stretching up into the wall, the skeleton of this latter consists consequently outwards of thick oxea, but inwards of thin ones. In the specimen with numerous thick oxea these at the same time thicker and upon the whole larger than in the other specimens. — Develop- PORII'KKA. III. 69 mental stages of the dermal spicules were seen in small numbers, they show that these spicules are diactinal from the first beginning, b. Microsclera; these arc chelae arcuatse; they have an evenh curved shaft, the terminal parts are relatively small, and the alae are somewhat triangular; the length is 0-034— 0-040 mm; the shaft is not cylindrical but a little flattened, the thickness is in relation to this 0-003— 0-005 """• The chelae occur through the whole sponge and outermost in the dermal membrane; they are especially numerous in the pore-membranes. Locality: Station 18, 61° 44' Lat. N., 300 29' Long. W., depth [135 fathoms; station 46, 61 32' Lat. W. n° 36' Long. W., depth 720 fathoms; station 64, 620 06' Lat. N., 190 00' Long. \Y., depth 1041 fathoms; station 85, 63° 31' Lat N., 250 21' Long. W., depth 170 fathoms. The localities are situated in the southern part of the Denmark Strait, South of Iceland and between Iceland and Faroe Islands. Grogr. distr. The species was described by Bowerbank from Scotland, depth 96 fathoms; Top- sent 1. c. records it from the Azores in depths of 448, 620, 756 and 1200 fathoms. It seems thus to have a very wide bathymetrieal range, from 96 to 1200 fathoms. 22. H. simillima n. sp. PI. Ill, Fig. 7, PL VII, Fig. 9. Intrusting ; surface smooth, bearing small oscular papilla and very low, poriferous warts, both with a dense skeleton of dermal spicules in the wall. Spicula: megasclera; the skeletal spicules acantho- styli with a small or no marked head, divided into two groups, large, only spiued at /he bos,. >,-_fi o-6j""". small, nearly spined in the whole length, 0-16 — o'/p""" ; the dermal spicules oxca with inter- mediates to foruofa, erjj — u-jy""" : microsclera strongly curved chelce arcuatce. 0-028 — n-n;j""". Of this species we have several specimens of various sizes, growing 011 larger and smaller pebbles, shells, Brachiopods and tubes of P/acosfegus trideutatus. They are present in the material in all sizes from quite small up to an extent of 30"""; the thickness is at most 07""". The colour (in spirit) is white to greyish white. The surface is smooth, without projecting spicules; other- wise it may have a somewhat wrinkled appearance on account of the papillae and impressed areas to be mentioned hereafter. The dermal membrane is a thin, but distinct and separable membrane; it rests on the skeleton below and is densely filled with chelae, but has no proper skeleton of horizontal dermal spicules. Oscula and pores: in the somewhat large and well developed specimens oscula are always found, they are conical papilla; with a simple opening at the summit. The pores are also limited to certain areas, which may be described .is very low, broad waits, somewhat recalling the structures in lu/latella viridis. They arc bounded by a low wall, being generally lower on oue side than on the other, the wart lying down towards the surface; the pore-membrane closes the opening and forms a sieve, it is densely filled with cliche. The pore-areas ma\ be of various, generalh relatively large diameters, up to 3""". When the sponge is examined with a lens, the pore-areas are only seen with difficulty; as they are so very low the pore-membrane is always sunk down on the tissue below and the port's not to be seen, and therefore the only thin- seen is a circular, depressed area, surrounded by a sharp edge. The skeleton. The dermal skeleton.; the dermal spicules form bundles and short fibres stretching PORIFERA. III. from the main skeleton, often almost from the base, upwards to the dermal membrane which rests on them; above they are more or less penicillately spread; they are somewhat perpendicular or more oblique and often somewhat decumbent. The skeleton in the wall of the oscular and pore-papillae is formed bv fibres stretching up in the wall and here forming a skeleton of close-lying, parallel spicules. There is no skeleton of horizontal spicules in the membrane, but this is provided with dense-lying chelae. The main skeleton is of the typical construction formed by vertical acanthostyli with their heads placed on the substratum; the longest of the styli may reach to or near to the surface. Spougin is present at the base, but only to a very slight degree. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli which are divided into two rather well defined groups of sizes. The large styli are straight or generally slightly curved near the head, this latter is small or not at all pronounced; the spines are only present on the head and a little way out, being here smaller and soon quite disappearing. The small styli are straight, the head is very small and for the greatest part clue to the somewhat longish, radiating spines; the style is spined nearly in the whole length, only a small apical part being smooth; the spines are often reclined; they are of moderate size or small, and in this respect there may be some difference in different specimens. The length of the large styli is 0-41— 0*65 mm with a diameter of the head of 0-020— 0-028 mm, and of the small styli 0'i6— 0-19""" and the thickness of the head about o,02i,,,m. 2. The dermal spicules are oxea with transitions to tornota; they are straight and generally more or less fusiform and somewhat long tapering and in this case they are oxea, the thinner ones are more cylindrical with shorter points and must be termed tornota. The length, which may vary a little in various specimens, is on the whole 0-32— 0-47""" with a diameter in the middle of 0-006—0-014""". The spicules have generally not quite equal ends, but one end is slightly thinner than the other; the thinner the spicule is the more pronounced is this difference, and some few very fine developmental stages were quite monactinal, thus showing that the spicule begins as monactinal. Besides the mentioned dermal spicules there are also in this species, as in the preceding one, some thicker, fusi- form oxea, they have a length of 0-29 — 0-35""" with a thickness in the middle of 0-015— 0-017 mm; they are very scarce, and as the measurements show, they seem to be connected in size with the ordinary spicules, only being specially short and thick, and in contrast to the case in the preceding species they are here shorter than the ordinary dermal spicules. So far as I have seen, these thicker spicules are found in the outer part of the fibres, just at the dermal membrane, b. Microsclera; these are chelae arcuatse; they have a strongly, sometimes semicircularly curved shaft, the alae are lobe-shaped, and short' and round; the length is 0-028—0-037""", the most strongly curved may sometimes be a little shorter; the shaft is somewhat flattened, its thickness is in accordance herewith 0-004 — 0-007 '"'"j developmental stages were seen in small numbers. The chelae are seen through the whole sponge, but only in small numbers, in the dermal membrane they form on the other hand a more or less dense layer, and they are numerous in the pore-membrane. This species is rather similar to and seems also nearly related to H. occulta, but it is charac- teristically distinct; as to the skeleton it is distinguished by the absence of a proper dermal skeleton, and with regard to the spicules the chelae have a different shape and are much more curved; also the difference in the development of the dermal spicules with diactiual beginning in one and monactinal PORIFERA. Ill- -] beginning in the other species is to be noticed. I think it very probable, that the specimens mentioned by Topsent (1. c.) from stations 600 and 899, and which the authoi refers with some doubl to //. occulta, belong to the present species, as he declares the spicules to be somewhat smaller, and especially as he observes, that the chelae are more curved than in the typical occulta; his figures belong on the contrary certainly to occulta. Locality: Station 9, 64" 18' Lat. N., 27 oo' Long. W., depth 295 fathoms; station 54, 63 08' I. at. \\. 15 40' Long. W., depth 691 fathoms; station 85, 630 21' Lat. N., 25 21' Long. W., depth [70 fathoms; station 98, 65° 38' Lat. N., 26° 27' Long. W., depth 138 fathoms; further it has been taken East of the Faroe Islands, depth 250 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902), at 66 20' Lat N., 25 t2' Long. W., depth 96 fathoms (Wandel), and at Angmagsalik in East Greenland, depth 140 fathoms (The Amdrup Expedition 1900). The localities are situated at East Greenland, West and South of Iceland and East of the Faroe Islands; the bathymetrical range goes from 96 to 691 fathoms. If the species mentioned by Topsent with more curved chelae and smaller spicules should prove to be the present species, it has also been taken at the Azores in depths of 185 and 106 fathoms. Remarks: The two species //. occulta and simillima show great resemblance, and they might be thought nearly related if it were not for the difference in the manner of development of the dermal spicules. The existence of this difference is very interesting, but it is not, however, possible to decide for the present its real importance. --- The occurrence of special dermal spicules besides the ordinary ones is also an interesting fact; these spicules seem to be only extreme variations of the ordinary form, and we have then here again a fact, showing that the spicules placed outermost in the sponge mav be liable to special variations, such as I have pointed out more particularly in Part II of this work (p. 32 — 33); also the difference in the abundance of these spicules in different specimens of the same species, as shown by occulta, has its parallel, as mentioned at the place cited. 23. H. baculifera Tops. PI. VIII, Fig. 1. 1901. Leptosia baculifera Topsent, Arch, de zool. exp. et gen. 3, IX, 354. 1904. Topsent, Resultats des camp. sc. du Prince de Monaco, Fase. XXY. 191, PI. XV, fig. 2. Tncrusting; surface without projecting spicules. Spicula: megasclera ; the skeletal spicules acaiifho- styli with a distinct head-swelling, spinal in the whole or nearly the whole length. 0077- 0-214""". divided into two groups; the dermal spicules strongyla -earring to subtylota <>■ i , <""•: mici small chelce arcuatce 0'02i — o'02jmm. This species forms very thin incrustations on stones and on tubes of Placostcgus tridentatus and other serpulid tubes. The greatest extent to which any of the specimens reach is 38' . and the thickness is about 0'3ram. The colour (in spirit) is whitish to brown. The surface has no projecting spicules, but seen with a lens it is finely gritty, caused b\ the skeletal styli. The dermal membrane is a thin film, it is filled with microscleres and supported by dermal spicules. Oscnla and pores I was not able U> detect. PORIFERA. III. The skeleton. The dermal skeleton. Besides the chelae filling the dermal membrane, this is supported by bundles of dermal spicules, which stretch upwards from the main skeleton; further some scattered spicules are present in the membrane. The main skeleton consists as usual of vertical acanthostyli with their head-ends fixed on the substratum. The longest of the styli reach to the dermal membrane, but without projecting through it. A slight amount of spongin seems to be found just at the substratum, but it is at all events difficult to observe. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli; they are straight or slightly and evenly curved; they have generally a somewhat distinct head-swelling, and they taper bom the head into a long apex, which may be more shortly pointed outermost. The spinulation is dense in the lower part of the style, but it is more dispersed outwards; in the longer spicules an apical part is smooth, while the shorter ones are spined to the point. The spines on the shaft are reclined, on the head they are placed more densely and are longer, radiating straight out and generally truncate. The acanthostyli vary much in size, but they are not divided into two groups. The length is 0077 — o-2i4mm, and the diameter at the base is o-on — 0-028™'". In some specimens the styli did not reach beyond o-i78mm. 2. The dermal spicules are strongyla varying to subtylota; they are straight, sometimes a little polytylote but only to a slight degree. The ends may be simply rounded but they are most frequently slightly swollen; they are not equal, one being a little thinner than the other, and this thinner end shows the most distinct swelling. The length varies in all between 0-15 and 0-238"""; in the single specimens the variation is only slight. The thickness is about 0-002 — 0-004 mm- b. Microsclera; these are chelae arcuatae; they are rather small, they have an evenly, generallv somewhat strongly curved shaft, but with regard to this curvature there may be some little variation; the tooth is lancet-like, and the alae of the same length as the tooth. The teeth have such a direction, that they lie in a straight line drawn from one end of the chela to the other. The length of the chelae is 0-02 1—0-025""", anu- the diameter of the shaft 0-002— 0-028 mm. The chela; occur in great numbers in the dermal membrane, sometimes somewhat scattered and sometimes quite close-lying; this difference is probably due to the greater or less contraction of the membrane. As I find no characters separating this species from H. baculifera Tops., I have referred it to tin latter; especially the figures cited appear to me very like the spicules in the present species. Locality: Station 1, 62° 30' Lat. N., 8C 21' Long. W., depth 132 fathoms; station 9, 64° 18' Lat. N., 27°oo' Ivong. W., depth 295 fathoms; station 54, 630 08' Lat. N., 150 40' Long. W., depth 691 fathoms; station 86, 650 03' Lat. N., 230 47' Long. W., depth 76 fathoms; station 94, 640 56' Lat. N., 360 19' Long. W., depth 204 fathoms; station 98, 65° 38' Lat. N., 26° 27' Long. W., depth 138 fathoms; further it has been taken at 63° 12' Lat. N., 20° 06' Long. W., depth 270 fathoms (The fishery investigation steamer "Thor"), and East of the Faroe Islands, depths 220 and 250 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902); m all about 14 specimens. The station on which most specimens were collected was station 85, the sponge here growing on tubes of Placostegus. The enumerated localities are situated in the Denmark .Strait, South of Iceland and East of the Faroe Islands. Geogr. distr. Topseut records the species from the Mediterranean North of Algiers, and at 38°35'3°" J-at- x-, 28° 05' 45" Long. W., depth about 660 fathoms. PORIFERA. Ill -, 24. H. levis n. sp. PI. VIII, Fig. 2. Incrusting and very thin; surface finely hispid. Spicula: megasclera ; the skeletal spicules acanthostyli with a somewhat swollen head and small spines, 0-08 — o-2jmm, not divided into two groups; the dermal spicules polytylote tylota or subtylota ir/6 — n-j/""": microsclera small chela> arcua 0'02I — 0'024""". The specimens of this species grow 011 Brachiopods, shells of Astarte and other mussels and on Placostegus tridentatus. The greatest extent, to which the species reaches, is 19' ; the sponge forms an exceedingly thin incrustation, the thickness is scarcely above o-ion,n'. The colour (in spirit) is light brownish yellow. The surface is finely and densely hispid from projecting skeletal spicules. The dermal membrane is a thin film. Oscula and pores were not observed. The skeleton. The dermal skeleton: the dermal spicules form bundles which go to the surface in an oblique, often very decumbent direction; these bundles are rather scattered. In the membrane the chelae are found sometimes rather numerously, at other times more scattered. The main skeleton consists in the ordinary way of acanthostyli witli the head-ends on the substratum; the larger of them project beyond the surface, making this hispid. A small amount of spongin is found at the base. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli which have a somewhat characteristic shape; they are straight or generally somewhat curved; the head-end is somewhat swollen, and they taper into a long apex; as they are rather thick at the head-end and are not especially long, they become slightly club-shaped. The head-end has strong spines, in the small styli the other spines are also rather pronounced, but in the larger ones the spines on the shaft are small, the shaft thus almost being merely gritty; in the longer styli the spines are scattered towards the point, but there is generally no long, smooth apical part. The size varies much, but the styli are not divided into two groups. The length is 0-08—0-25 mm, the styli thus being rather short; the diameter of the head is about 0-014 — o-03mm. 2. The dermal spicules are slender, straight tylota or subtylota which are distinctly polytylote; they have a generally rather distinct, longish swelling at each end, the shaft is a little thinner in one end, and the swelling in this end is therefore more marked than in the other. The length is 0-16— 0-21 mm, and the diameter about 0-0028— 0-004 mm. D- Microsclera; these are chelae arcuatse; they are rather small, the shaft is somewhat strongly curved, the alee are nearlj triangular and the tooth elliptical and of the same length as the ake. The length of the chela is o-02i— o-o24mm, a"d the diameter of the shaft about o-oo28mm. The chelae seem to he confined to the dermal membrane. This species stands very near to baculifera, but I consider it as distinct; it is especially the slightly spined acanthostyli which distingush it, and the dermal spicules are also more distinctly polytylote. Locality: .Station 9, 640 iS' Lat.N., 270 00' Long.W., depth 295 fathoms; station 25, 63 30'Lat.N., 540 25' Long. W. , depth 582 fathoms; station 85, 630 21' Lat. N., 25 2i' Long.W., depth 170 fathoms; station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; further it has been taken at 62 M'l.at.W. 50 17' Long.W., depth 160 fathoms (Ad. Jensen, tin- cruise of "M. Sars" [902). In all seven specimens. The localities are situated in the Davis Strait, the Denmark Strait and Easl of the Faroe Islands. I'll.- Ingolf-Ejcpedition. VI. \. -, PORIFERA. III. 25. H. bractea n. sp. PL, VIII, Fig. 3. Incrusting; surface hispid. Spicula: megasclera; the skeletal spicules acanthostyli, divided into two groups, lar^e. with a small head, only spined in the lower part, 0-28 — o-j6""n, small, without head, entirely .pined. 0-12— o- 15"""; the dermal spicules tylota 0-27— 0-50"""; microsclera chela; arcuatce 0-028 — o-ojj""". Of this species we have only a very small specimen, and the description will therefore in some respects not be quite satisfactory. The specimen grows on a Brachiopod-shell together with a specimen of Hymenancora duplicata n. g. et sp. (to be described hereafter), and a small specimen of Melonanchora emphysema. It forms a very small, almost circular incrustation, scarcely two millimeters in diameter and very thin; it bears about in the middle a low, cylindrical papilla. The colour (in spirit) is greyish, and the sponge is somewhat transparent. The surface is in the present state hispid from projecting skeletal styli. About the dermal membrane I can say nothing, and also nothing about pores and oscula; probably the papilla mentioned is an osculum, but I could not observe it. The skeleton. The dermal skeleton seems to consist of scattered bundles of dermal spicules, and it is, so far as I could observe, relatively weakly developed. The main skeleton is constructed in the ordinary way and consists of vertical acanthostyli with their heads on the substratum, and it is somewhat dense; the longest of the acanthostyli project beyond the surface, and it seems to be so also in the undamaged sponge. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli which are divided into two groups, large and small. The large acanthostyli are straight, they have a small head-swelling and taper evenly into a long apex which is a little more abruptly pointed outermost; they are spined only on the basal part, at most on the half part; the spines are of medium size, largest below; they are placed most densely on the head-swelling, but more dispersed outwards. The small styli have no head-swelling; the base is the thickest part and from here they taper evenly to the point, thus as- suming a club-like shape; these styli are spined in their whole length, the spines at the base radiate straight out, those on the shaft are reclined. The length of the large styli is 0-28— 0-36 n,m, and the diameter of the head is about 0-02"'"'; the length of the small styli is 0-12— 0-15""" with a diameter at the base of o-oi4mm. 2. The dermal spicules are straight and somewhat slender tylota, the end- swellings are distinct but not large; the length varies rather considerably, from 0*27 — o-50mm, and the diameter of the shaft is 0-004 — 0-007 mm. D- Microsclera; these are chelae arcuatae, they have a curved shaft, elliptical teeth and lobe-shaped but somewhat narrow alas. The length of the chela is 0-028 — 0-034""", and the diameter of the shaft 0-004-— 0-005 ram. The chelae seem to occur through the whole tissue, but are seen especially at the surface. Locality: Station 89, The Denmark Strait, 640 45' Lat. N., 27° 20' Long. W., depth 310 fathoms. 26. H. laevistylus n. sp. PI. VIII, Fig. 4. Incrusting. Spicula: megasclera; the skeletal spicules acanthostyli with a very small head, only spined on and just al I he head, for the rest smooth, very uniform in size. 0-44 — 0-48"""; the dermal spicules tylota varying t<< strongyla, 0-27 — o-j4mm; microsclera chelee arcnatcr 0-045 — 0-052""". PORIFERA III Of this species only one very small specimen is present, growing as an incrustation on the inside of a Pecten-shell ; it is longish and has a greatest extent of only 3-5 The colour (in spirit is whitish. The dermal membrane is thin and densely filled with chelae. Oscula and pores were not observed. The skeleton. The dermal skeleton consists of bundles and spicules, which are scattered in different ways from near the base to the dermal membrane; it seems to be rather diffuse; there is no skeleton of dermal spicules lying horizontally in the dermal membrane, but this latter is densely filled with chelse. The main skeleton seems to be somewhat slightly developed, it consists of acanthostyli which are all of the same size, and have the heads based on the substratum. I could detect no spongin. Spicula: a. Megasclera. 1. The skeletal spicules are very slightly spined, almost smooth acanthostyli; they are straight or slightly curved and have a sligbtly inflated head; this latter bears more or fewer, but generally only few small spines; near the head the style may be very finely grittv, but for the rest it is quite smooth. The styli are only of one form and very slightly varying in size, so that small forms do not occur. The length is about 0-44— 0-48 l,ni, and the thickness of the head is about 0-017""". 2. The dermal spicules are tylota, which are straight, slightly thickened in the middle and with small end-swellings; these latter may be very small or absent, the spicules thus becoming strongyla; the length is 0-27 — 0-34 """ and the thickness in the middle 0-005 — 0-007 """• D> Micro- sclera; these are chelse arcuatas; they have a rather curved shaft which is a little recurved at the outermost extremities, the alae are lobe-shaped and the tooth narrowly elliptical; the length of the chelae is 0-045— °'°5 2'""\ and the thickness of the somewhat flattened shaft is 0-005— 0008 '""'. The chela occur in specially large numbers in the dermal membrane. This species is easily distinguished and stands somewhat apart on account of its almost smooth styli, which are all of nearly the same length. Remarks: It might be thought, that this species represented only a young stage of some other sponge (a Lissodendoryx\ but I do not think this possible. To be sure we have no investigations on the skeleton of the youngest fixed stages of the sponges which may come into consideration here, and it is therefore not known, what the first beginning of the skeleton is in species with a reticulate or dendritical skeleton, and it is not impossible, that the styli may at first be placed vertically. The structure of the present species seems so fully to conform with that of Hymedesmia, however, that 1 think it must be in reality a Hymedesmia-, the styli with a somewhat distinct head, and especially the chelae being crowded in the dermal membrane are good characters of Hymedesmia. Loeality: Station 89, the Denmark Strait, 640 45' Lat N., 2; 20' Long. W., depth 310 fathoms. 27. H. Bowerbanki n. sp. PI. Ill, Fig. 8a, PI. VIII, Fig. 5. Incrusting, thin: surface smooth. Spicula: megasclera; the skeletal spicules short, club-shaped, strongly and entirely spined acanthostyli of one size o- 09 o-/j""H; tin- dermal spicules tylota o-u microsclera chela arcuatm 0-020- o-oj4n"". 76 rORIKERA. III. Of this species one specimen grows on a stone together with H. clavigera; on the stone besides grow a Polymastia and a Mesapos; another specimen is growing on a worm-tube. The -[Miuge has a greatest extent of 12 mm; it is exceedingly thin, not over o-2mm, and its thickness is not or only slightly greater than the length of the skeletal styli. The colour (in spirit) is whitish, somewhat milky. The surface is smooth, without projecting spicules. The dermal membrane is very thin, transparent and not separable; it has no proper skeleton. Oscula and pores were not observed. The skeleton. The dermal skeleton; the skeleton formed by the dermal spicules consists of bundles lying irregularly between the erect acanthostyli; they are more or less horizontal, but stretch up to the membrane; also some single scattered spicules are seen, but there is no dermal reticulation. The main skeleton is of the ordinary structure, consisting of erect acanthostyli with the heads based on the substratum; as they are of about the same length, they all reach just to the dermal membrane but none of them project beyond it. I could detect no spongiu. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli; they are of a very characteristic shape and to a high degree recall the styli figured by Bowerbank for H. zetlandica ; they are short and robust, conically tapering and without any head-swelling; they are strongly spined in their whole length; the spines at the base are radiating straight out, while the other spines are directed somewhat downwards; the styli are only of one size and not much varying in length; this is 0-09— 0'0i3mm and the thickness at the base (the spines, as always, included) o-02imm. 2. The dermal spicules are tylota; they are straight, somewhat thickened in the middle, and the end-swellings are small; they have a length of 0-19— o-238mm, and a diameter in the middle of 0-007— 0-009 mm. b. J/icro- sclera; these are chelae areuatae which have a somewhat curved shaft and small end-parts, the alse are somewhat lobe-shaped, rounded downwards, the tooth is elliptical. The chelae have a length of 0-020— 0-034 '"'" and a thickness of the shaft of 0-0028— 0-005 mm respectively; the larger sizes are by far the most numerous. The chelae are present in the dermal membrane in somewhat considerable numbers, but not at all forming a layer. This species is evidently nearly allied to //. zetlandica; it has the same outer appearance and skeletal structure, and the shape and dimensions of both megasclera and chelae are in close agreement as also the fact that the styli are of only one form; but //. zetlandica has sigmates, while the present species has only chelae for microsclera. Locality: Station 85, 63°2i' Lat.N., 250 21' Long. \V., depth 170 fathoms; further at 650 50' Lat N., 260 53* Long. W., depth 208 fathoms (The Fishery investigation steamer "Thor"). The localities lie in the Denmark Strait. — As said above, one of the specimens grows on a stone together with several other sponges and among these a specimen of H. clavigera (PI. Ill, Fig. 8 a and b.). These two I lymedesmia species grow side by side and quite uniting, but they are easily distinguished from one another by their characteristically different aspects, clavigera is whitish, but appears somewhat darkened on account of the black stone shining through it; it is hispid and shows the canals as darker points; Bowerbanki on the contrary is of a milky colour, it has a smooth surface of a quite uniform aspect, not showing canals. PORIFERA. III. / I 28. H. truncata 11. sp. PI. Ill, Fig. 9, PL VIII, Fig. 6. Incrusting, thin; surface smooth, bean'//- some small cylindrical or conical oscular papilla with a dense skeleton 0/ dermal spicules in the wall. Spicula: megasclera; the skeletal spicules short, some- what club-shaped, strongly ami entirety spined acanthostyli, truncate at the apex and with a neck- shaped constriction above the base: they are of one size 0-065— 0-077 mm; the dermal spicules tylota 028 — 0-369"""; microsclera chela- arcuatw 0-021 — 0-023""". Most specimens of this species grow incrusting on stones, one specimen on a Brachiopod-shell and one on a fragment of a mussel-shell; the specimens are of different size-, the largest reaches an extent of 4oram; the thickness is very small, generally scarcely exceeding 0-3 """. The colour (in spirit) is light bluish white, somewhat milky. The surface is entirely smooth without projecting spicules. The dermal membrane is thin and transparent, it is generally easily separable, and seems to be without spicules, resting on the skeleton beneath, but the facts with regard to the dermal membrane are not easily understood; the membrane has a curious, skin-like appearance and consistency, and it is generally filled with cells containing somewhat refriugent granules ("cellules spheruleuses"?), and 1 think the mentioned state of the membrane is due to the influence of alcohol; in most of the speci- mens there is moreover outermost a thin, brownish film, more or less easily separable, which is, I think, formed by influence of the alcohol on some sort of mucus. Oscula and pores: In most of the specimens there are some cylindrical or slightly conical papillae on the surface; they may reach to a length of 3mra; these papillae are oscular tubes with the oscular opening at the summit, though in the present state they are generally closed. The number of papilla? present in the various specimens varies from two to eleven. The two smallest specimens showed no papillae. Pores were not observed. The skeleton. The dermal skeleton consists of bundles of dermal spicules, which stretch from the main skeleton, or almost from the base, and up towards the dermal membrane; they are thus lying obliquely or more or less horizontally. In some places the bundles are more numerous than in others, but most frequently they are scattered and not at all numerous; the bundles are rather thick, consisting of numerous spicules. Near the oscular tubes the bundles form fibres which run from various sides into the oscular papilla and form in the wall of the papilla a dense layei of spicules lying parallel to the longitudinal axis of the papilla. The main skeleton: In most places the main skeleton is con- structed in the ordinary way, the acanthostyli are erect, with their heads based on the substratum; they reach from the base to the dermal membrane, but do not project beyond it: they are, at all events in most places, rather close-standing. I could not detect an\ spongin. Such is, as said, the structure of the skeleton in most places, and I think these are the places where the sponge is quite undisturbed; but in many other places this is not so, the acanthostyli may here be King down and crossing each other in all directions, and, what is the most remarkable fact, they may be lying more or less horizontally in or near the dermal membrane; in most places they are then crowded together, in others they are much more scattered. Whether this condition is normal or not, I am not able to say with certainty, but I think it is due to contraction, especiall) as the normal Hymedesmia- arrangement of the skeleton is seen in many places. It was staled above, that the dermal membrane 7« PORIFHRA. III. appeared to be somewhat transformed by the preservation in alcohol, but the whole sponge is also evidently highly influenced by the alcohol, the surface being wrinkled to a high degree. I am inclined to think that the exceedingly thin sponge is somewhat mucous in the fresh state, and then is highly contracted by the influence of the alcohol, and this would fully explain the remarkable condition >een in the skeleton. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli of a very characteristic shape; they are short and straight, slightly tapering towards the point, this latter is broadly truncate, so that the spicule is nearly cylindrical; they are strongly spined in the whole length, only a little above the base there is an unspiued part, and this part is also a little thinner than the rest of the spicule, thus forming a characteristic, neck-shaped constriction; though there is no real head- swelling, the shape mentioned gives the base of the spicule the appearance of a head. Only very rarely the neck-formed constriction is less obvious. The length of the acanthostyli is very uniform, 0-065 — o-077ram, and the diameter at the base is 0-017— 0-024 mm. 2- The dermal spicules are tylota; they are straight and rather robust, and they are of the same or nearly the same thickness in the whole length, but just before the ends they are somewhat narrowed, and this narrowing gives rise to the rather slight end-swellings. The shaft is often slightly polytylote. The length is 0-28— 0-369""", and the diameter 0-009— o-oi2mm. b. Microsclcra; these are chelae arcuatse; they have a curved shaft, the teeth are so directed that they are lying in a straight line drawn between the ends of the chela; the alse are somewhat narrow and rather incised in the lower margin when seen in front view; the tooth is narrowly elliptical. The chelae are small, the length is 0-021 — 0-023 mm an^ the thickness of the shaft about o-oo28mm. Not rarely chela; occur which are thicker and more robust in all parts, but these give the impression of not being quite normal. The chela; are seen in the dermal mem- brane and in the other parts of the sponge, but generally not in great numbers, on the other hand they are very numerous on the oscular papillae. This species is nearly related to // Bowerbanki, but it is easily distinguished by the characteristic acanthostyli as also by several other more minute characters. Locality: Station 85, 63°2i'Lat. N., 25°2i' Long.W., depth 170 fathoms; station 89, 640 45' Lat. N., 27° 20' Long. W., depth 310 fathoms; further it has been taken in Forsblads Fjord in Hast Greenland, depth 50—90 fathoms (The East Greenland Expedition 1900), at 66° 54' Lat. N., 150 38' Long. W., depth 58 fathoms ("Beskytteren"), South-west of Sudero, depth 180 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). The localities are situated on the East coast of Greenland, in the Denmark Strait, North of Iceland and at the Faroe Islands. 29. H. latrunculioides n. sp. PL III, Fig. 10, PL VIII, Fig. 7. Incrusting ; surface smooth, bearing some oscular papilla- with a dense skeleton of dermal spicules in the wall. Spicula: megasclera; the skeletal spicules short, conical, very strongly spined acanthostyli with a neck-shaped constriction above the base ; they are 0/ one size o-o6j — o-oji""" ; the dermal spicules tylota, but often with such small swellings, that they approach nearly to strougyla, o-jo — crjv""" : micro- ra cliche arcnatir irojj — 0-028""". POR1FERA. III. This species greatly resembles the preceding one in external appearance. < >ne specimen is growing on a stone, which it has nearly quite overgrown, its greatest extent may be estimated to 22m,,;; three other specimens grow on a stone together with specimens of Histodcrma physa, Hymedesmia nttmmulus, H. filifera and Plocamia sp.; the largest of these specimens is 12111 in greatest extent. The thickness of the sponge is about 0-5""". The colour (in spirit! is whitish with a slightly bluish, somewhat milkv tint, but in places it may be shaded brownish on account of a film-like covering, such as mentioned in the preceding species. The surface is smooth. The dermal membrane is thin and lias no pp skeleton; it is of the same curious, skin-like consistency and appearance as in truncata, and it has very probably been mucous in the living state of the sponge. Oscula and pons; with regard to the oscula the facts are quite as in truncata; on the largest specimen there is a cylindrical, rather large oscular papilla about in the middle, it has a length of 6mnl. Pores were not observed. The skeleton is constructed quite as in truncata. The dermal skeleton consists of somewhat scattered bundles of spicules, the bundles generally consisting of rather many spicules; at the base of the oscular papilla the bundles form fibres which stretch up in the wall of the papilla, here forming a dense spiculation of close-lying, parallel spicules. The main skeleton consists in the ordinary way of erect acanthostyli placed with the heads on the substratum; the spicules are rather close-standing. So far as I could observe there is no spongin present. For the rest the skeleton in most places shows all the same conditions and alterations as described above under truncata, and I think these conditions are clue to the same factors as suggested for this species. Thus the present species also gives the im- pression of being strongly contracted, and the dermal membrane is obviously wrinkled and folded, and moreover it also shows numerous cells with refringent granules. Spicula: a. Megasclcra. 1. The skeletal spicules are acanthostyli of a very characteristic shape; they may to some slight degree remind one of the discasters in Lairuncalia. They are short, thick and regularly conical; they are strongly spined, and the spines are large, radiating hori- zontally, not reclined; there is no head-swelling, but there is a slightly thinner and unspined part above the base, forming, as in truncata. a neck-shaped constriction, and this constriction makes it seem as if a head-swelling were present; the constriction mentioned and the outermost point are the only smooth parts. The length is very uniform, 0-065 — o-ojr""" and the diameter at the base is 0-022— 0-027 n,m. 2- The dermal spicules are tylota, but the swellings are often so small that the} are nearly strongvla; they are straight with a cylindrical shaft of equal thickness in the whole length; sometimes they are very slightly polytylote. The length is 07,0 o-40ram, and the diameter is 0-008-0-0 1 3 mm. b. M/crosclera: these are cliche arcuatae; the) have a slighth curved shaft, the akv are lobe-shaped and the tooth elliptical; the lower edge of the aloe is somewhat incised when the chelae are seen in front view. The length is 0-023— °'('-'s lll<1 tnc diameter of the shaft 0 0-005""". The chelae may varv somewhat, being more slender or more robust, and some oi them art found showing a very robust shape, giving the impression of being not normal but influenced In abnormal deposition of silica. Tin chelae occur especially in the dermal membram . and on the oscular papilla they are present in great numbers. This species is related to the two preceding, but it is characteristically distinguished, especially by its acanthostyli, but also by several other characters. 8q PORIFERA. III. Locality: Station 85, 63°2i'Lat. N., 250 21' Long. W., depth 170 fathoms; station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; both localities lie in the Denmark Strait. Remarks: The three species Bowerbanki, truncata and latrunculioides form together with zet- lini dica Bow. a group of related species; zctlandica is however distinguished from the three others by possessing sigmata; truncata and latrunculioides are the two most nearly related species. A fifth species which seems also to belong here on account of its uniform acanthostyli and dermal tylota is the H. tenuissima Dendy (established by the author under the generic name of Myxilla), and perhaps also a sixth species must be referred to this group, viz. H. obtusata Tops., but this latter species has no microsclera; its curious, obtuse acanthostyli with a little knob at the apex vary a little more than the acanthostyli in the other species, from 0-13 to 0'23mm. If the views about the relationship of these species are correct, and they are certainly so at all events with regard to the first four species, we have an interesting example which shows, that in a group of nearly related species we may have forms with chelae and sigmata, with chelae alone, and with no microsclera at all. This confirms the view advanced in the introduction to the genus, that it is not possible to create genera here according to the presence or non-presence of the mentioned forms of microsclera. 30. H. irregularis n. sp. PI. VIII, Fig. 8. Incrusting ; surface partly smooth partly hispid. Spicula: megasclera; the skeletal spicules acanthostyli with a distinct head, the smaller spined in the whole length, the larger with a smooth apical part, 0-12 — 0-50""", not divided into two groups; the dermal spicules polytylote styli 0-298 — o-jp"""; microsclera chela' a rata tec 0-040 — 0-050""". This species generally forms incrustations on small stones, a couple of specimens grow on shells of Astarfe sulcata; the greatest extent to which the sponge reaches is about 20 mm, but most specimens are smaller; three of them, which grow together on a pebble are quite small, the smallest only 4"'m. The thickness is scarcely more than 0-5 n,m. The species is of a somewhat irregular appear- ance, because it, at all events generally, does not grow flat 011 the substratum but has imbedded in its base some small particles and gravel. The colour (in spirit) is yellowish grey to whitish. The surface is in some places smooth, in other places densely hispid from projecting dermal spicules. The dermal membrane is a somewhat solid membrane, densely charged with chelae. Oscula and pores were not observed. The skeleton. The dermal skeleton ; in the dermal membrane the chelae are close-lying, forming a layer; the skeleton formed by the dermal spicules is strongly developed; it consists of spicula- bundles or fibres which stretch from the main skeleton or quite from the base up towards the surface, outermost the bundles are penicillately spread and support the membrane; the spicules sometimes terminate just in the membrane, sometimes they pierce it more or less. When the sponge is examined from above under the microscope, fan-shaped, more or less decumbent bundles of dermal spicules are therefore seen. The dermal spicules all have the pointed end turned outwards. The main skeleton consists in the ordinarv wav of acanthostvli with the head-ends based on the substratum; on account PORIFERA. III. of the irregularity of the substratum on which the sponge grows, the styli may show sonic irregularity with regard to direction. On the same account there may be great difference with regard to the relation of the main and the dermal skeleton to one another: when the sponge grows directly on the shell or the stone the construction is the common one, and the larger styli reach to the surface; but when the substratum is irregular, and the sponge therefore- grows thicker in places, the skeleton formed of the dermal spicules increases in extent and forms fibres going up to the surface; thi- skeleton forms in such places the greatest part of the whole skeleton of the sponge, the main skeleton always remaining formed of the vertical styli attached to the substratum. A small amount of spongin seems to be found at the base, but at all events onlv to a very slight degree. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli ; the) arc straight or generally somewhat curved near the base; the curvature is present especially in the lunger styli. The styli have a distinctly marked, globular head, and they taper into a long, fine apex. As commonly the small styli are entirely spined, the longer the styli are the more dispersed are the spines, and the longer a part of the apex is smooth. The spines on the head are densely placed, and they are the largest; on the shaft they are compressed and reclined. The styli vary much in size; even if the intermediate forms are rare, there are however not two separate groups of size. The length is o-i2— 0'50n'm, and the diameter of the head is croai — 0-030™"". 2. The dermal spicules are- of a very characteristic shape and must be termed styli; tliev are straight, one end is rounded, the other tapers evenly into a long apex which is more abruptly pointed outermost; the spicules are- thickest in the middle, and the}- are polytylote, showing on the middle part a series of swellings; near the rounded end there is a somewhat sudden narrowing which forms a handle-like part. The- length of the dermal spicules is 0-298—0-39™"" and the diameter in the middle o-oo6 — o-oio""". 1>. Microsclera; these are chelae arcuatce; they are of ordinary shape with an evenly curved shaft, an elliptical tooth and alee of the same length as the tooth. The length of the chelse is 0040— 0-050 mm] the- shaft is some- what flattened, its diameter is in front and side view about 0-004 — o-oo8 mm respectively. The cliche are- found, as mentioned, in the dermal membrane forming a dense layer. Locality: Station 10, 64° 24' Lat. N., 280 50' Long. W., depth 788 fathoms; station [6, 65 1.3'LatN., 260 58' Long. W., depth 250 fathoms; station 85, 63 21'Lat. N., 25 21' Long. W., depth 170 fathoms; further it has been taken in the Denmark Strait at about 65 "Lit. X., depth unknown, at 620 29' Lat N., 50 17' Long. W., depth 160 fathoms and South-west of Siulero, depth [80 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). About ten specimens in all. The- localities lie- in the Denmark Strait and at the Faroe Islands. 31. H. proxima n. sp. Tab. VIII, Fig. 9 Incrusting; surface hispid. Spicula: megasclera; the skeletal spicules acanthostyli ivithont a real head, divided into two groups, large, only spined l>, I <•-„•. <>■ , •""", small, entirely spined. arm tne diameter of the shaft about 0-0038— 0-005 mm. The chelse occur, as mentioned, in the dermal membrane, but they are also otherwise seen in the body of the sponge. This species is nearly related to the preceding one, //. irregularis, it is however distinguished from this by characteristic differences; thus in contrast to irregularis it is hispid from projecting skeletal spicules, and the chelae do not form a dense layer in the dermal membrane. But the most PORIFERA III. characteristic differences lie in the spicules, the acanthostyli have no pronounced head, they are more slender and are divided into two groups; the dermal spicules are not polytylote, and the chelae have a diffreent shape and are smaller. Locality: Station 85, 630 21' L,at. N., 250 21' Long. W., depth 170 fathoms; the station lies in the Denmark Strait. 32. H. crux O. Schmidt. PI. Ill, Fig. n, PI. VIII, Fig. 10. 1875. Desmacidon crux O. Schmidt, Jahresber. der Comm. zur wissensch. Unters. der deutsche Meere in Kiel fiir 1872 — 73, 1875, 118, Taf. I, Fig. 10 — 11. 1903. Hymedesmia crux, Thiele, Arch, fiir Naturgesch. Jahrg. 1903, I, 392, Taf. XXI, Fig. 26 a d. /I/crusting; surface smooth, generally with line, oscula-bearing, conical warts with a skeleU dermal spicules in the wall. Spicula: megasclera; the skeletal spicules acanthostyli with a well-marked head, spined in the whole length, 0-12 — o'j8""", not divided into two groups; the dermal spicules sub- toruota varying through tornostrongyla to strongyla, they are polytylote, "'-/-- 0'j8m "■' : microsclct arena fee with a spined shall, croji — o-o^j""". ( »i this remarkable and very interesting species we have about ten specimens; they form small or more extended incrustations on stones and worm-tubes, one grows on a Pec ft //-shell; the greatest extent it reaches is about 35mm, and the thickness lies between 0-5 and i",m. The colour (in spirit) is yellowish red, brownish red or reddish, the sponge may thus vary somewhat in colour, but it always tends towards reddish. Schmidt 1. c. says about the colour "braungelb", and one of the Ingolf specimens is stated to have been yellow in the fresh state. The surface is smooth in so far as there are no projecting spicules, but it is often wrinkled and folded to a higher or lower degree; tin-- latter fact is probably only due to contraction. The dermal membrane is rather thick and solid, and it is easily separable; it is very densely charged with chelae, more densely than in any other species of Hyme- desmia; the chelae form a dense and solid layer. Oscula and pores: oscula are found as low, conical warts scattered on the surface; they have an opening <>r a depression in the summit, and around this the surface may be a little stellately rugose. In my specimens the waits ,ue. as said, quite low, sometimes scarcely elevated above the surface; Schmidt says on the other hand "Oscula auf unregel- massigen Papilleu"; according to this it would seem, that the oscular cones ma) sometimes be higher, if it is not irregular folds of the surface, that Schmidt has mistaken for cones. In some specimens the warts are easily discernible, in others they are more or less indistinct, and they may be quite absent. Pores I have not seen and cannot say whethei they are scattered or perhaps collected in definite areas; sometimes some larger, dendritically branched canal- 111. i\ be seen through the dermal membrane. The skeleton. The dermal sir /clou: the most protective skeleton of the dermal membrane is formed by the mentioned dense layer of chelae; the dermal spicules form bundles stretching from main skeleton, often almost from the base, up to the dermal membrane; in the membrane itself dermal spicules are found. Around the oscula the dermal spicules form .1 special osculai skeleton, the 84 PORIFERA. III. spicules here forming fibres which run stellately to the top or the middle of the cone, but also here the fibres run below the dermal membrane and not in it, and the dense layer of chelse continues just to the centre of the cone. The main skeleton consists in the ordinary way of perpendicular acantho- styli with their heads on the substratum; the longest styli reach up to the dermal membrane. At the base a small amount of spougiu is present. Spicula: a. Megasclera, i. The skeletal spicules are acauthostyli; they are slightly curved, generally nearest the base, and they are somewhat densely spined in their whole length; the head is round and generally well marked; the spines on the head are straightly radiating, on the shaft they are reclined. The spicules vary much in length, but as all intermediate sizes are present they are not divided into two groups; the length is 0-12 — o-38nim and the diameter of the head 0-02 — 0-03 mm. 2. The dermal spicules are straight and very slightly fusiform; they may be termed subtornota, but generally one end is rounded so that the)' are tornostrongyla and also both ends may be rounded, the spicules thus being strongyla; they are distinctly polytylote. The length is 0-27— 0-38 mm and the diameter 0-006—0-008 mm. b. Microsclera are chelse arcuatse of a very characteristic and remarkable shape; the shaft is very strongly curved, sometimes to so high a degree that its end-parts form two nearly parallel arms; on the middle of the hinder side of the shaft there are a number of strong spines. Also the shape of the end-parts of the chela affords great interest; the tooth is protruding greatly forwards, but it is formed almost entirely of the strongly developed falx, while there is nearly no plate, the falx only being somewhat thickened at the front edge; the alse are also very interesting, they quite resemble the falx in shape and they are of the same size, further they are directed straight out to each side, so that they form right angles with the falx, on the other hand they are not or almost not bent forwards. The whole construction of the end-parts recalls the construction characteristic for the ancorse, but I shall otherwise draw no conclusion from this fact at present. The chelse are nearly always somewhat coutorted. Same few developmental stages were seen, they show spines on the shaft already when rather thin. The length of the chela, which is somewhat dependent on the degree of the curvature, is 0-031 — o-o43m;", and the diameter of the shaft, the spines not included, is 0-005 — 0-007 n,m. As mentioned the chelse form a dense layer in the dermal membrane, but they are also seen in the other parts of the sponge. Locality: Station 9, 640 18' Lat. N., 270 00' Long. W., depth 295 fathoms; station 81, 6i° 44' Lat N., 27 oo'lyong. W., depth 485 fathoms; station 85, 63° 21' Lat. N., 2 50 21' Long. W., depth 170 fathoms; station 98, 65°38'Lat.N., 260 27'Loug.W., depth 138 fathoms; further it has been taken at 65° 50' Lat. N., 260 53' Long. W., depth 208 fathoms (The Fishery investigation steamer "Thor"), and West of the Faroe Islands in depths of 160 and 180 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). In all about ten specimens. The localities lie in the Denmark Strait and West of the Faroe Islands. Geogr.distr. Schmidt had the species from South-west of Bukenfjord, Norway, depth 106 fathoms. 33. H. aenigma n. sp. PL IX, Fig. 1. hit rusting ; surface tor the most part hispid, zoif/i some conical projections , hearing oseula- Spicula: megasclera; the skeletal spicules acanthostyli with no real head-swelling, they are entirely PORIFERA. III. spiiicd, o-ij—o-j4mm, not distinctly divided into two groups; the dermal spicules somewhat fusiform, polytylote tornota, 0-32— o-jj"""; microsclera curious asteroid chela 0-028— 0-035""*. This species grows incrusting on a Brachiopod-shell together with some other incrusting sponges; it has a greatest extent of 20""" and a thickness of about o-5mm. The colour (in spirit) is greyish brown. The surface is for the greatest part densely hispid from projecting dermal spici but in one end it is smooth, and here there are a couple of conical projections, forming oscular cones. As I have only one specimen, I cannot say, whether it is characteristic for the species that the oscular cones are thus restricted to a special part of the surface. The dermal membrane is thin and not separable; it is densely charged with the curious chelae. The skeleton. The dermal skeleton ; as said the microscleres form a dense layer in the dermal membrane; the dermal spicules form fibres and bundles stretching in various ways from the main skeleton or quite from the base up to the dermal membrane; the direction of the fibres is generalh almost horizontal, and they reach therefore some length; they are also rather strong, of an average thickness of cro42mm; they terminate in the dermal membrane. The membrane is pierced by spicules which seem to be more or less scattered or forming penicillately spread bundles. As far as I could observe these projecting spicules rise from the underlying fibres, probably from the ends of these; the}' seem to be wanting or are at all events few in number on the smooth part of the surface, where the oscular cones are found. The fibres formed of the dermal spicules run into the oscular cones, forming in the wall of the cone a dense skeleton of parallel spicules with the ends towards the summit of the cone; above this skeleton the layer of microscleres lies. Quite down at the base of the sponge there is found a number of dermal spicules lying singly and horizontallv and thus not taking part in the formation of the fibres. The main skeleton is constructed in the ordinary way and consists of vertical acanthostyli with their heads based on the substratum; the skeleton is not dense, the styli being somewhat scattered. At the base a scarcely perceptible amount of spongin is found. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli; they are straight or slightly curved, the basal end is the thickest part, but there is no real head-swelling or only a slight one. The styli are spined in the whole length, the spines are of small or medium size and reclined; on the head-end they are larger and straightly radiating. The length is o-i^- <>',v| , and the diameter at the base is 0-014 — o-02imm. The styli cannot be said to be divided into two groups but the middle si are however rare. 2. The dermal spicules are tornota, the)' are straight or slightly curved and somewhat fusiform, and they are more or less polytylote. The length is 0-32 0-43 and the diami in the middle 0'Oo6— 0-007 mm. b. Microsclera; these are bodies of a very curious shape. I nun term them asteroid chelae. Roughly speaking they present a cylindrical shaft which at each end divides into three branches, each bearing at the end four compressed, two-pointed teeth, placed in a square; the shaft is more or less curved. On closer examination it becomes evident that this curious body is a chela. It is as a rule possible to trace the shaft or main axis (PI. IX. Fig. 9c), and one of the til branches at each end is the direct continuation of the axis; this axis answers to the shaft and the teeth in an ordinary chela; the two other branches at each end, which are generally a little tmnner than the axis, answer to the al;c; they issue from the hinder side oi the shaft; but the ends oi the shaft itself and of the alar branches are all developed in the same way, splitting into four compressed, 85 PORIFERA. III. two-pointed teeth, the exact shape of which may be seen in the figures. Such are the facts generally, but it is however not always possible to decide, which of the branches belong to the axis, the branches often being so uniformly developed that they all seem alike. The chela is somewhat contorted, so that when seen from the end all six branches become visible, and we get a figure almost like a six- rayed aster. (PI. IX, fig. if). The length of the chela from one end of the shaft to the other is 0-028 — °'°35""" allu- tQe thickness of the shaft is 0-004 — 0-005 mm. That these bodies are transformed chelae is seen also from the developmental stages, of which some were found (PI. IX, fig. ig); these consist of a curved axis with two lateral dilatations near each end, and they resemble to some degree develop- mental stages of other chelae, only that the tooth is here not curved forwards. — These chela; remind one somewhat of the chelae in II. Schmidti Tops., but are different in many respects; they are very interesting and take an intermediate position between the previously described, more or less trans- formed chelae; //. crux has normally shaped, but spined chelae, II. Schmidti has likewise spined chelae, but much more transformed, in II. aenigma they are still more transformed, and finally we find in //. vidua the chelae transformed almost to spined staves. — The chelae occur in the dermal membrane forming a dense layer, and they are also found scattered in the tissue lower down in the sponge. Locality; Station 89, 64° 45' Lat. N., 27° 20' Long. W., depth 310 fathoms. The station lies in the Denmark Strait. Remarks: While at present only few species are known with spined chelae — I think only the above mentioned and Pseudohalichondria clavilobata Cart. (Ann. .Mag. Nat. Hist. 5, XVIII, 1886, 454, PI. X, fig. 8) — there are on the other hand some fossil forms, described by Hinde and Holmes (Journ. of the Linn. Soc. XIV, 1894, 214, PI. XI, figs. 8 — 14); the authors figure seven chelae, which they think belong to four species, two of which are named as Pseudohalichondria deformis and oamaruensis. The forms are all referred to the genus Pseudohalichondria Cart, evidently only on account of the spined chelae. As already mentioned by Top sent in his work from 1904, there may be some reason to think, that the described chelae belong to species of Hymedesmia. The chelae were found in lower Tertiary strata in New Zealand. It is somewhat curious, that such chelae are known as fossil, since the spination and higher or lower transformation of the chelae must certainly be considered as a feature of recent origin. Probably therefore the genus Hymedesmia, containing only incrusting forms of a simple structure, is an old genus. 34. H. filifera O. Schmidt. PL III, Fig. 12, PI. IX, Fig. 2. 1875. Desmacidon filiferum O.Schmidt, Jahresber. der Comm. zur wissensch. Unters. der deutsche Meere in Kiel fiir 1872 — 73, 1875, 117, Taf. I, Fig. 6. 1903. Hymedesmia filifera, Thiele, Arch, fiir Naturgesch., Jahrg. 1903, I, 391, Taf. XXI, Fig. 25 a — c. Incrusting. but not ft/in; surface smooth, bearing a number of thin, cylindrical oscular and porc- papillce. The dermal membrane solid, until horizontal spicules. The skeletal/ formed of dermal spicules strongly developed, the main skeleton rather weak. Spicula: megasclcra ; the skeletal spicules entirely spined acantliostyli with the basal end not or slightly thickened. s ■ The largest of our specimens has a greatest extent of 25""°; the specimen figured by Schmidt 1. c. is 35 '""■ long. The colour (in spirit) is greyish or dirty yellowish. The surface is smooth without projecting spicules. The dermal membrane is a tough and solid, easily separable membrane which is provided with horizontal spicules. Oscula and pores: the mentioned appendages are by Thiele (1. c.) declared to be oscular papillae, and this is also the case with some of them, but the greater part are pore- papillae; the oscular papilke have a simple opening in the summit, while the pore-papilke have here a pore-sieve stretched over the opening. So far as I could see on my somewhat damaged material there is also some difference in the shape of the papillae, the oscular papilke being more conical and the pore-papilloe cylindrical and somewhat widened towards the apex. The skeleton. The dermal skeleton ; the skeleton formed by the dermal spicules is by far the largest part of the whole skeleton. The spicules form fibres which run in different directions quite from the base up to the dermal membrane; these fibres consist of many spicules and are generally rather thick, they may f. inst. reach to a diameter of 0'36mm. In the skin the spicules lie horizontally and in more than one laver, thus forming a close skeleton; they lie in all directions, but however somewhat bundle-like; the bundles in the different layers generally cross each other. Finally the dermal spicules form the skeleton in the wall of the papilke; they lie here in the longitudinal direction, but the spicules in the different layers crossing each other under acute angles and rather regularly. The main skeleton is formed mainly in the ordinary way of acanthostyli with their heads on the sub- stratum; they do not reach to the dermal membrane. Where the fibres of dermal spicules rise from the base, they are seen to have just their basal end formed by acanthostyli. Spongin is found ai the base. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli; they are straight or verj slightly curved; the basal end is not or only slightly thickened; they taper evenl) into the apex, but the outermost point is not long. They are spined in the whole length, on the base the spines are large and radiating, giving thus to some degree the impression of a head-swelling; the spines on the shaft are reclined. The styles vary much in length, but there are no groups. The length is 0-13- o-27mm and the diameter at the base 0-017— 0-028 mm. 2- T,lc dermal spicules are strongyla; they are slightly fusiform and have nearly always a curious and characteristic double curvature, more rarely they are somewhat irregularly curved or nearly straight; the length is 0-27 — 0-45 """, varying a little in different individuals, and the diameter in the middle is 0-007 "'"'-'"'"• b. Microsclera are ch< arcuatse; they have a regularly curved shaft, the end-parts are not large, the tooth is elliptical, the ala; have generally the lower edge but slightly incised ami are more or less triangularly lobe-shaped in side view. The length is 0-030— 0-035mm and the thickness of the shaft about 0-003" The chelae are found rather richly in the tissue quite down to the base, they are often abundant!} present along 88 PORIFERA. III. the fibres; in the dermal membrane they are much less frequent, but in the papillae they are more frequent on the inside, and they are very numerous in the pore-sieves. The identification of this species leaves no doubt according to the description and figures by Thiele; e. g. his figure of the strongyle with the characteristic curvature is quite in agreement. Schmidt mentions "Spangen", and Thiele has also found some single sigmates, but he thinks, that they do not belong to the species; now it is curious enough that I also found sigmates, but quite singly, and I think too, that they do not belong to this species; they are very scarce, and as the species always envelops some incrusted material, it is easily understood, that foreign sigmates may occur in it. Locality: Station 2, 630 04' Lat. N., 90 22' Long. W., depth 262 fathoms; station 15, 66° 18' Lat. N., 25° 59' Long. W., depth 330 fathoms, (bottom temperature -r-o°75C); station 25, 630 30' Lat. N., 540 25' Long. W., depth 582 fathoms; station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; further it has been taken at 620 26' Lat. N., 40 49' Long. W., depth 220 fathoms, and 62° 29' Lat. N., 40 12' Long. W., depth 283 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). The localities lie in the Davis Strait, the Denmark Strait and at the Faroe Islands. The species is certainly an inhabitant of the warm area; to be sure station 15 has a negative bottom temperature, but this station is situated at the very border between the cold and the warm areas. Geogr. distr. The species was hitherto only known from Norway, South-west of Bukenfjord, depth 106 fathoms (Schmidt 1. a). 35. H. grandis u. sp. PI. Ill, Figs. 13-14, PL IX, Fig. 3. Incrusting, but of massive appearance ; surface smooth, bearing a number of thin, cylindrical oscular and pore-papilla. The dermal membrane solid, with horizontal spicules. The skeleton formed of dermal spicules strongly developed, the main skeleton weak, chiefly consisting of bundles of spicules, f a rming the lowermost part of the fibres of dermal spicules. Spicula: megasclera ; the skeletal spicules acanthostyli with a very slight or no head, spined almost in the whole length, 0-41 — 0-75""" (not divided into two groups/ 1 : the dermal spicules long strongyla 0-48 — o'So""" ; mie rose/era two forms, chela: ureuatcr 0-042 — 0-048 """, sigmata o-ojr — o-og6mm. The specimens to hand of this species all grow on aggregated, large sponge-spicules; these spicules are then overgrown, enveloped or more or less imbedded by the sponge; although the species must thus in reality certainly be considered as incrusting, it has however an outer appearance of being more or less massive; the upper part of the sponge has at the same time a somewhat bladder- like consistency which also contributes to its massive outer appearance. The surface bears a generally great number of long, thin papillae or appendages which may reach to a length of 12 mm with a dia- meter of o-5 — i-5mm. The appendages may be more or less erect or decumbent, and they are generally more or less curved. The whole sponge is generally folded and wrinkled in different ways. The species may reach a considerable size, the largest specimen is about 50 mm long and has an apparent height of i5mm. The colour (in spirit) is dirty yellowish or greyish white. The surface is smooth without projecting spicules. The dermal membrane is solid and easily separable, and it is provided PORIFERA. III. 89 with horizontal spicules. Oscula and pores: the mentioned papillae are oscular and pore-papillae; in outer appearance there is almost no difference between the two kinds, only the- oscular papillae arc- generally more conically pointed at the apex, while the pore-papillae are more broad here; the latter are closed by a pore-sieve, while the oscular papillae have a simple opening in the summit. The p< ire- papilla; are more numerous than the oscular papillae. The skeleton. The dermal skeleton; the skeleton consisting of tin- dermal spicules forms the greatest part of the whole skeleton; it consists of fibres and bundles which stretch in an irregular way from or nearly from the substratum up to the dermal membrane; the course of the fibres is, as said, irregular, and they are often more or less curved, and may thus be seen running somewhat parallel with the surface; the fibres may be of very different strength, but often rather thick, up to 0-3""", and consisting of many spicules. In the dermal membrane the spicules lie horizontally, but irregularly, crossing each other in all directions; they lie somewhat scattered, and the membrane is to be seen everywhere between them; they lie thus much more scattered than in filifera, and not bundle- like collected. The skeleton of the papillce is constructed quite as in filifera, ami also here the spicules cross each other regularly and under acute angles. The main skeleton is quite irregular and scattered on account of the way in which the sponge grows on the substratum; it forms thick bundles scattered everywhere between the foreign sponge-spicules and other particles of the substratum, and always forming the lowermost part of a fibre of dermal spicules; the acanthostyli are thus not at all evenly distributed at the base of the sponge, but verv scattered and only present as bundles, from which fibres of dermal spicules proceed. The bundles are generally large and consist of many spicules, they may have a thickness of 0-5 mm. At the base of the bundles there is a distinct mass of spongin. Spnula: a. Megasclera. 1. The skeletal spicules are long and slender acanthostyli; they are straight or nearly so and evenly tapering, but the outermost point is short; they have no or only a very slight head-swelling and are somewhat densely spined at the base and some way out, but on the largest part of the shaft the spines are somewhat scattered; at the base and especially a little above it the spines are somewhat large, but for the rest they are small. The sty li do not generally vary much in length, from 0-41 — c>75mm with a diameter at the base of crcm — 0-020 """; it will be seen that there is thus no very great difference in size between the styli; some smaller ones may however be found, reaching only criSn"" in length, but these are very scarce and perhaps not always present 2. The dermal spicules are long strongvla; they are straight, sometimes slightly, irregularly curved, and they may be slightlv polytylote; the ends may be very slightly swollen. The length is o-8omm, and the diameter in the middle 0-007- irm;, Microsclera; these are of two forms, chelae arcuata; and sigmata. 1. The chelae have a curved shaft, tin- free middle part of which is about one third of the length of the chela, the alae are lobe-shaped, the tooth elliptical, pointed. The length is 0-042— o-048mm, and the diameter of the shaft o-cx>s— oxx)jnm. 2. The sigmata are of e. .111111011 shape, more or less contorted up to a quarter of a turn; they vary considerably in .size, the length — o-oo,6mm and the thickness relatively 0-002 0-006 '; the larger forms are the most common. The two forms of microsclera occur at definite places in the sponge; in the dermal membrane both chelae and sigmata are present in equal numbers; tin- chehe occur moreover in the wall oi the papilla?, The [ngolf-Expedition. VI. .*. oq PORIFERA. III. especially outwards, and in rather great numbers in the membrane forming the pore-sieves, and in these places no sigmata occur; on the other hand, the chelse do not occur in the inner body, while the sigmata are present here in enormous numbers, filling the tissue and also occurring everywhere in the basal parts among the particles of the substratum. The consequence of this distribution of the microscleres is that the sigmata are far more numerous than the chelse. Embryos. In one of the specimens, which was cut through, some embryos were found; they reached to a diameter of 0-65 mm; they smallest of them had no spicules, but the larger were richly provided with microsclera, both chelse and sigmata; both forms were smaller than in the grown sponge, the chelae 0-031""" and the sigmata not surpassing oo40mm; also in the embryo the sigmata were far more numerous than the chelae. No megascleres were present. Locality: Station 78, 6o°37'Lat.N., 27° 52' Long. W., depth 799 fathoms; station 84, 620 58' Lat. N., 250 24' Long. W., depth 633 fathoms; station 90, 640 45' Lat. N., 290 06' Long. W., depth 568 fathoms. In all five specimens. The localities lie in the Denmark Strait and on the eastern slope of the Reykja- naes Ridge. 36. H. digitata n. sp. PL III, Fig. 15, PI. IX, Fig. 4. Incrusting or of somewhat massive appearance ; surface smooth, bearing some thin oscular and pore-papilla- ; the dermal membrane with horizontal spicules. Spicula: megasclera; the skeletal spicules acanthostyli, divided into two groups, large, without a distinct head and not entirely spined, 0-25 — o-jj'""'. small, with a distinct head and entirely spined, o-u — 0-14""" ; the dermal spicules tylota 0-26 — o-^iy""" ; microsclera two forms, chela- arcuatce 0-034 — o-ojS""", sigmata 0-028— o-ojo""". This species resembles the preceding in outer appearance, but the specimens present are small; we have only two specimens, growing on stones together with other species of Hymcdestnia and some other incrustiug sponges. The sponge forms a basal, iucrusting or more massive part, from which a number of long, thin papillae issue; in the present specimens the number of papillae does not exceed three; they are of the common shape and reach to a length of 7'""1. As said the specimens are small, the basal part has a greatest extent of about 511"". The colour (in spirit) is yellowish or whitish. The surface is smooth, and the dermal membrane constructed as in the preceding species. Oscula and pores are connected with the papillae quite as in the preceding species. The skeleton. The dermal skeleton; the skeleton formed of the dermal spicides consists of more or less distinct fibres going from the basal skeleton towards the dermal membrane; in the membrane the spicules lie horizontally, and they are as usual lying close in the wall of the papillae in the longitudinal direction, intercrossing at acute angles. The main skeleton consists of basal acantho- styli with their heads on the substratum. Spongin is present, but only to a very slight degree. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli; they are divided into two rather distinct groups, large and small; the large styli are slightly curved, they are thickest at the base but without any real head-swelliug; they taper evenly but the outermost point is short, and they are spined in somewhat more than the basal half; the spines are small, only at the base a little larger. The small styli are straight and have a distinct head, the shaft is beset with relatively large PORIFERA. III. gj spines in the whole length, the spines are directed downwards; on the head there are rather long, radiating spines. The length of the large styli is 0-25— 0-31 mm, and the diameter at the base 0-021 : the small styli are cvii— 0-14 """ long with a diameter of the head of 0021"". 2. The dermal spicule-, are tylota which are cylindrical and straight or slightly, irregularly curved; the end-swellings are not large but distinct; the length is 0-26— 0-417""" and the diameter in the middle O'OOS— o-oo8 . b. .\ficro- sclera are of two forms, chelae arcuatae and sigmata. 1. The chelae have an evenly curved shaft, the free middle part of which is a little more than the third part of the length: the ahe are lobe-shaped and the tooth elliptical, rounded at the end. The length is 0-034 — 0'038""" and the diameter of the shaft 0-005""". 2. The sigmata are of ordinarv shape, more or less contorted up to a quarter of a turn. The length is 0-028— 0-050 """ and the thickness between 0-002 and 0-003""". ^he chelae and sigmata seem to be present in about equal numbers; the chelae occur in the wall of the papillae, and for the rest both forms of microscleres seem to occur, so far as I could ascertain, through the whole body. This species is distinguished from the preceding in regard to the spicules by the smaller acantho- styli, the tylote dermal spicules and the much smaller sigmata; also the chelae are slightly different. Locality: Station 89, the Denmark Strait, 64° 45' Lat. N., 2JC 20' Long. YV., depth 310 fathom-. Two specimens. 37. H. trichoma n. sp. PL III, Fig. 16, PL IX, Fig. 5. Incrusting; surface smooth, bearing thin papillce. The dermal membrane with horizontal spicules. Spicula: megasclera; the skeletal spicules acanthostyli with a small head, spined in the whole length, they are divided into two groups, large. 0-20 — 0-24'""', smalt, o'li — o'/j"""; the dermal spicules tylota 0-29 — o-jA'""" ; microsclera two forms, chelcs arcuata 0-034 — 0-042""", plane sigmata 0-058— 0-075""". Of this species we have only one specimen growing on a shell of an Astartc; it forms a thin incrustation of a greatest extent of onlv 6mm, and it bears one loug and thin papilla. The colour (in spirit) is light brownish. The surface is smooth. The dermal membrane is thin and not easily separated. About oscula and pores I can say nothing, as said, onl) one papilla is present The skeleton. The dermal skeleton: the skeleton formed of the dermal spicules consists of bundles stretching from near the base to the dermal membrane; in the membrane there are horizontal spicules, but they are scattered and not at all dense-lying. The main skeleton is arranged quite in the ordinary way, consisting of erect acanthostyli with their head on the substratum and evenly distributed over it; the largest of them reach to the surface. A small amount of spougin seems to lie present. Spicula: a. Megasclera. 1. The skeletal spicules an- acanthostyli which are straight 01 nearly so, the head-swelling is small, and they taper slightly towards the point, which is short; the) are rather densely spined in the whole length, hut the spines are small, onh longer at the base; though they do not vary much in length the) are yet divided into two distinct groups; the length of the large styli is 0-20—0-24""", and of the small 0-11 — 0-13"""; tne diameter of the head is about 0-Q21 and it is nearly the same in the large and the small styli on account of the basal spines being largei Q2 PORIFERA. III. in the small than in the large styli. 2. The dermal spicules are tylota, they are straight or generally slightly and somewhat irregularly curved, often with a curvature recalling to some degree that found in the dermal spicules of H. filifcra; the end-swellings are small, sometimes almost dis- appearing; the length is 0-29— 0*38 mm and the diameter 0-004— 0-007 mm. D- Microsclera are of two forms, chelae arcuate and sigmata. 1. The chelae have a curved shaft the free middle part of which is more than one third of the length, the alas are lobe-shaped, their lower margin not much incised; the tooth is narrowly elliptical; the length is 0-034 — 0-042 mm and the diameter of the shaft about 0-003 mm. 2. The sigmata are of common shape, but they are quite or nearly quite plane; the length is not very variable 0-58— 0-75 mm, generally nearest the latter size; they are relatively thin, the thickness being 0.0028 mm. As far as I have been able to ascertain, both chelae and sigmata occur through the tissue, while in the dermal membrane only the chelae occur, but here in great numbers, and in places lying densely. Of the microsclera the chelae are the most numerous. This species is distinguished from grandis and digitata by its plane, thin sigmata and besides by characters in the other spicules. Locality: Station 85, the Denmark Strait, 63° 21' Lat. N., 250 21' Long. W., depth 170 fathoms. One specimen. 38. H. macrosigma n. sp. PI. IX, Fig. 6. hi c rusting ; surface smooth. Spicula : megasclcra ; the skeletal spicules acanthostyli with a small head-swelling, spiued in the zvhole length, but the spines much dispersed outwards, 0-13 — 0-28""", not divided into two groups ; the dermal spicules strongyla or subtylota 0-23 — 0-28 '"'"'; microsclera three forms, chelw arcuatce 0-020— 0-032""", sigmata of two forms, large 0-18—0-208, small o-o6—o-o8g""". We have three specimens of this species, one of them grows on aggregated sponge-spicules; it incrusts these all round, so that they are chiefly situated in the interior of the sponge, but stretching out here and there. Of the other two specimens one grows on a Brachiopod-shell, the other on a basalt block. The specimens are rather small, one only about 8mm, the others 12 mm in greatest extent. The colour (in spirit) is yellowish white or yellow. The surface is smooth without projecting spicules. The dermal membrane is thin, it is densely charged with chelae and sigmata; some small, circular openings could be observed in it. The skeleton is highly irregular and confused in the first examined specimen, viz. that im- bedding sponge-spicules, on account of the manner in which the sponge envelops the substratum. The dermal skeleton is represented by dermal spicules which are found scattered through the whole sponge; in single places they may form a bundle stretching towards the surface; in the dermal mem- brane they are not seen, or at all events only some few, while, as said, the membrane is filled with microscleres. In one place the dermal spicules were lying parallel and forming something like a conical projection -- perhaps an oscular cone — but the state of the specimen did not allow this to be decided. The main skeleton is still less developed, and the acanthostyli are only present in small numbers; they are seen here and there with the head based on the substratum but otherwise quite confused and pointing in all directions. While the skeleton is thus on the whole little developed, the sponge is on PORIFERA. III. q. the other hand densely filled with microseleres. When a vertical section is examined, the view is therefore somewhat curious; in the interior foreign sponge-spicules are seen, and for the rest the microseleres are predominant, filling the other space, the dermal spicules being only seen scatt between the other elements, and it is only by close examination that an acanthostyle can be observed here and there. The condition of the skeleton is, as seen below, due to the way in which the sponge grows, and the principle of the construction is evidently the same as in the other species of Hyme- desmia. There seems to be a little spongin at the base of the acanthostyli. — ( )n examining the other specimens, which only came into my hands later, it proved, that the skeleton was here of the ordinary construction and the styli were as usually placed on the substratum; otherwise it agreed with the above description, the other space being occupied by dermal spicules and densely charged with micro- seleres. Here also the styli of the skeleton were somewhat scarce and arranged very dispersedly. It is of some importance to notice the facts with regard to these different specimens, as we see it clearly proved here, that specimens of Hymedesmia may, when growing on loose material, assume a shape and a manner of growth which may give rise to mistakes by influencing the arrangement of the skeleton, though the construction of this latter is principally the same as in species of Hyme- desmia growing on a flat and firm substratum. Spiaila : a. Megasclera. i. The skeletal spicules are acanthostyli; the) are straight and the head-swelling is small or wanting; the spines on the basal part are somewhat large and close-standing, on the rest they are small, reclined and few in number; the smallest styli are somewhat more spined. The length is 0-13 — 0*28 mm and the diameter at the head about 0-020""". 2. The dermal spicules are straight, cylindrical strongyla or subtylota; the ends are generally swollen, but only to a very slight degree. The length is 0-23— 0*38 min and the diameter is 0-0057— 0-007 """. b. Microsclera are three forms, chelae arcuatse and sigmata of two sizes. 1. The chelae are of the common shape, the shaft is curved, the tooth elliptical and the ake lobe-shaped; they vary somewhat in size, the length is 0-020— 0-032""" and the diameter of the shaft 0-0015— 0-0028 n,m. 2- '^'ie '^rge sigmata are of ordinary form, but somewhat elongated and generally only slightly contorted; they are of a considerable and very- uniform size, the length is 0-18— 0-208 n,m and the thickness 0010 -o-on """. 3. The small sigmata are of a less regular shape and they are contorted, generally a quarter of a turn or nearlj so; their length is o-o6— 0-089""" an£l tMe thickness 0-003""". As said the microseleres occur in great numbers all through the tissue; in the dermal membrane all three forms occur, but the cheke are here present in greatest number and very close-lying. This species shows, in one specimen, a manner of growth quite as is found in grandis, and it also shows resemblances to this species otherwise, but it is easily distinguished from it and from the related species by the presence of two forms of sigmata. As seen from the description I have not been able to decide whether the species in a more pelted Mate may be provided with papillae. Locality: Station 54, 630 08' L,at. N., is 40'Long.W., depth 69] fathoms; station 78, 60 37'LatN., 270 52' Long. W., depth 709 fathoms; station 89, 640 45' I„at. N., 27 20'Long.W., depth 310 fathoms. The localities lie in the Denmark Strait and .South of Iceland. l}. PORIFERA. III. 39. H. pugio n. sp. PL IX, Fig. 7. Tncrusting; surface somewhat hispid. Spicula: megasclera ; the skeletal spicules acanthostyli with a distinct head, only spined on the lower part, they are divided into two groups, large 0-38 — 0-54""" , small a 12 — 0-20"""; the dermal spicules thin styli 0-27 — o-ji"""; microsclera two forms, cliche arcualce , _v — 0-040""", sigmata, small and curved in a somewhat circular may, plane or nearly plane, 0-014 —o-o /?""". Of this species we have one specimen, growing on a stone; it forms a thin incrustation of a greatest extent of about 2omm, and the thickness does not exceed 0-5""". The colour (in spirit) is white. The surface is somewhat hispid from the projecting acanthostyli. The dermal membrane is thin and not separable, sparingly provided with dermal spicules, but somewhat more richly with chelae. A number of circular openings of canals are seen shining through the membrane. The skeleton. The dermal skeleton is not much developed; it consists of dermal spicules which are, so far as I could ascertain, lying partly more or less horizontal in the membrane, but for the greatest part projecting. The main skeleton consists of acanthostyli with the heads placed on the substratum; it is rather dense with the spicules close-standing; the longest of the styli project through the dermal membrane. The heads of the styli are at the base inserted in a somewhat slight mass of spongin. Spicula: a. Megasclera. r. The skeletal spicules are acanthostyli which are straight or only very slightly curved and taper evenly into a long apex; the head is round and not large but distinct. They are spined at the base and some way out, but the larger apical part is smooth; the spines are small. With regard to size the styli are divided into two groups, but otherwise they are quite similar. The large styli have a length of 038 — 0-54""" with a diameter at the head of 0-021 — 0*028 """j the small styli are 0*12— o-20mm long and the head 0-015— 0-021 n,m thick. The small styli are the most numerous. 2. The dermal spicules are rather thin styli which are cylindrical, straight or slightly curved and taper into a long and fine point. The length is 0-27 — 0-31 ram with a diameter of about 0-003 "Ira. b. Microsclera are of two forms, chelae arcuatee and sigmata. 1. The chelae have a sometimes rather strongly curved shaft and relatively small eud-parts; the alaa are lobe-shaped but somewhat narrow, the tooth is elliptical. The size of the chelae is somewhat variable, the length being 0-021— 0-040 mm and the thickness of the shaft 0-004—0-006""". 2. The sigmata are very small and fine and they are somewhat circularly curved, so that the length is not much greater than the breadth; they are plane or almost plane; the length is 0*014— 0*017 """ an^ the thickness o-ooimra or still finer. Both forms of microsclera are seen especially in or near the dermal membrane. Embryos. The specimen contained a great number of embryos; they are globular or lentiform and they were easily seen in the thin sponge on account of their white colour. They have an average diameter of 0-35""". They contained either no spicules or also developmental forms of the chelae but uo megascleres. Locality: Station 15, the Denmark Strait, 66° 18' L,at. N., 250 59' Long. W., depth 330 fathoms (bottom temperature -j- o° 75 C). Only one specimen. PORIFERA. III. gr 40. H. consanguinea 11. sp. PL IX, Fig. 8. Incrusting; surface finely hispid. Spicula: megasclera; the skeletal spicules acanthostyli with a small or no head-swelling, they are divided into two groups, large, with a smooth apical part, o 0-29""", small, entirely spined, oio—o-rj"""; the dermal spicules tornota, ow<;—o-/pmm; microsclera two forms, chela- arcnatcr trcuS — 0-057 """. contorted sigmata 0-014 — 0-0/7""". This species grows as thin incrustations on living Brachiopods and one on a Retepora: the sponge covers generally the whole shell and may thus reach a greatest extent of 16 " ; it is exceed- ingly thin, not reaching 0-5 mm in thickness. The colour (in spirit) is whitish. The surface is short and finely hispid. The dermal membrane is very thin and hardly observable. The skeleton. The dermal skeleton is not much developed and somewhat diffuse; it consists of small bundles formed by a few spicules; the bundles stretch from the skeleton below up to the dermal membrane. The main skeleton is constructed in the ordinary way and consists of acanthostyli with the heads based on the substratum; the styli are not densely placed. The longer styli stretch beyond the dermal membrane, thus giving rise to the hispidity of the surface. .So far as I could observe there is a very small amount of spongin at the base of the skeleton. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostvli which are divided into two well separated groups, large and small. The large styli are straight or generally slightly curved near the base; they are thickest at the base but have no or only a small head-swelling; they taper evenly from the base, but the apex itself is not long-pointed; the styli are somewhat densely spined in almost the lower two thirds, the spines being less dense outwards; at the base the spines are somewhat large and blunt, for the rest they are small. The small styli have a similar shape as the large, but they are spined in the whole length. The large styli have a length of o-2i — 0-29 mr' and a diameter at the base of o-oi8— 0'025",m. The small styli are o-io — o-i3mm long with a diameter at the base of about o-oi4mm. 2. The dermal spicules are tornota which are somewhat thin, straight and cylindrical; the ends have short points; they are not of a simple tornote shape in so fai as one end has a generally slight swelling; sometimes also the other end may show an indication of a swelling. The length of the tornota is 0-15— o-i9'nm and the diameter about o-0025 b. Microsclera are of two forms, cheke arcuatae and sigmata. 1. The chelae have a slightly curved shaft and relatively small end-parts, the ake are lobe-shaped and the tooth elliptical. The length of the chela is 0-028 0*057 and the diameter of the shaft 0-003 — o-oo6mm. 2- ^n*-' sigmata are thin and contorted, generally a quarter of a turn; their length is 0-014— O'oi; and the thickness cvoooS""". The microscleres are seen through the whole tissue of the sponge. This species shows some resemblance to //. (Hymeraphia) mucronata Tops, with regard t<> the different categories of spicules, but the size of these is different for all forms and especiallj lor the tornota, and there is onlv one form of cliche in the present species. The species is easily distinguished from the preceding by the sigmata and the tornote dermal spicules. Locality: .Station 25, 630 30' Lat. N., 54 25' Long. W., depth 582 fathoms, and at 70 32' Lat N., 8° 10' Long. W., depth 470 fathoms (The Rydei Expedition [891 92). In all five specimens, The localities lie in the Davis .Strait and the Denmark Strait. 96 PORIFERA. III. 41. H. planca n. sp. PI. X, Fig. 1. Incrusting y surface densely hispid. Spicula: megasclera; the skeletal spicules acanthostyli with- out a distinct head, divided info two groups, large, only s pined at the base, 0-35—0-65""", small, spined about in the lover half, o-/6 — o-2j""": the dermal spicules tylotornota o-2i — o-2g""" ; viicrosclera thee/ forms, cliche arcuaUe but tne s^aPe remains the same. PORIFERA. III. The shaft is not cylindrical but somewhat flattened and therefore of different thickness in side and front view, the thickness is in relation to this and to the size of the chela 0-003 a,H' o-oo6mm to 0-007 and o-onmm; the larger chelae are the most numerous. Sometimes the chelae have the shaft li strongly curved. 2. The sigmata of the larger form are somewhat irregularly curved and they are contorted, always a quarter of a turn or nearly so; their length is rather constant, about 0-021 — o-028mm and the thickness about o-ooin,m. 3. The small sigmata quite resemble the sigmata in //. pitgio; they are likewise strongly curved, and they are plane; their length is about 0-014 mm and the thickness scarcely goes beyond o-ooo8mm. The microsclera occur through the whole tissue and the chelae are seen in great numbers in the dermal membrane. Locality: Station 15, 66° 18' Lat. N., 25° 59' Long. W., depth 330 fathoms (bottom temperature H- o° 75 C); station 25, 630 30' Lat. N., 540 25' Long. W., depth 582 fathoms, and East of the Faroe Islands, depth 230 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). The localities are situated in the Davis Strait, the Denmark Strait and East of the Faroe Islands. The species must be an in- habitant of the warm area; it is true that station 15 shows a negative bottom temperature, but this station lies just at the very border between the cold and the warm areas. The three species just described must be somewhat nearly related, but besides by other characters they may be distinguished by their sigmata alone; //. pitgio has only small, plane, circularly curved sigmata, consanguinea only contorted sigmata and planca two forms, contorted and plane. 42. H. cultrisigma n. sp. PI. X, Fig. 2. Incrusting; surface hispid. Spicula: megasclera; the skeletal spicules acanthostyti villi a -eery slight or no head, they are divided into hvo groups, large, only spined below, o'^6—o'8om'", small, spined in the basal half, 0'2i — o'jo"""; the dermal spicules tylota 0'2j — o-jj""" ; microsclera three forms, cliche arcuate o'026—o'oj2""". sigmata of two forms, large, peculiar, somewhat band-shaped. JJ"""> small, plane, o-oij — 0-020""". This species grows as very thin incrustations on different bottom material as pebbles and shell-fragments and in one case on a Hexactinellid skeleton. The greatest extent it reaches is rl it may vary a little in thickness, but it is however always very thin, not reaching "S ' ■ The colour (in spirit) is whitish. The surface is in the present condition of the sponge very hispid with long projecting spicules. The dermal membrane is a thin film. Oscu/a and pores were not seen, but some circular canals could be seen through the dermal membrane. The skeleton. The dermal skeleton is formed by bundles of dermal spicules stretching from or almost from the base to the surface; the bundles have a move or less oblique direction and are often almost horizontal for a distance; they do not project beyond the surface, and there are no spicules lying in the membrane itself. The bundles are generally weak, consisting of only lew spicules. The main skeleton has quite the ordinary construction and consists of acanthostyli with the heads placed on the substratum; the long styli project beyond the surface. At the base there is a small amount of spongin. The Ingolf-Expedition. VI. \ '3 98 PORIFERA. III. Spicula: a. Mcgasclera. i. The skeletal spicules are acanthostyli which are divided into two sizes, large and small; the large styli are slightly curved near the head which is only slightly thickened, while the other end forms a long-pointed apex; the head and a short space above it are spined, while the whole of the rest of the shaft and apex is smooth. The small acanthostyli are generally straight and with the head still less thickened; they are more spined than the large, the spines covering the basal half part or more, and the spines are relatively larger. The length of the large styli is 0-56— o-8omm and the diameter of the head about 0-028 mm, of the small styli 0-21 — o-30mm with a diameter of 0-021 — 0-025 mm. 2- The dermal spicules are tylota; they are straight and the shaft is slender, the end- swellings are distinct, but they are not formed abruptly but pass gradually into the shaft. The length is 0-25 — 0-32 mm and the diameter of the shaft is 0-003 mm. Some few developmental forms were found, the thinnest of them being monactinal. b. Microsclera are of three forms, chelse arcuatse and sigmata of two forms and sizes, large, peculiar, and small. 1. The chelse are of ordinary shape, the shaft is evenly curved and the end-parts are relatively small; the tooth is elliptical and the alse lobe- shaped; the shaft is flattened, elliptical in section. The chelae vary somewhat in size, the length is 0-026— 0-042 mm and the thickness of the shaft 0-004— o-o 10 mm; with regard to the latter measurement it must be remembered, that the shaft is about twice as thick when seen in front as when seen in side view. The intermediate sizes of the chelae are scarce and hence they could be said to be present in two groups of sizes. 2. The large peculiar sigmata are of a curious shape; they may be de- scribed as having the curved end-parts somewhat long and terminating in a hook; they are contorted generally a quarter of a turn, and the hooks are again bent a little out of the plane; but the most interesting feature is that the rod forming the sigma is not cylindrical but compressed and thus somewhat baud-shaped. The size of the sigma from one curve to the other is 0-028 — 0-035""", an<^ the thickness is o-ooi and 0-003 """ f°r the small and the large diameter respectively. 3. The small sigmata are of ordinary shape and they are plane; the length is 0-014 — o-020mm and the thickness about o-ooi """. The chelse are present especially in the dermal membrane and rather numerous; the two forms of sigmata are seen through the whole body. Locality: Station 78, 6o°37'Lat. N., 270 52' Long. W., depth 799 fathoms; station 81, 6i°44'Lat.N., 27° 00' Long. W., depth 485 fathoms. In all three specimens. The localities are situated on the Reykja- naes Ridge South-west of Iceland. 43. H. mucronata Tops. PI. X, Fig. 3. 1904. Hymeraphia mucronata Topsent, Resultats des camp, scient. du Prince de Monaco, Fasc. XXV, 165, PL XIV, fig. 4a-d. IncrusUng; surface hispid. Spicula: mcgasclera; the skeletal spicules acanthostyli with no distinct head, the larger spined at the base, the small entirely spined, 0-12 — 0-65""", not divided into two groups ; the dermal spicules fusiform oxytornota 0-22 — 0-268""" ; microsclera three forms, chela- of two forms, ordinary 0-021—0-025""", peculiar, with some processes at each end, 0-021 — 0-026""", sigmata. large and fine, 0-028 — 0-05/""". PORIFERA. III. gg Of this interesting species we have one specimen growing as a small incrustation on an Ony- chocclla; its greatest extent is 8""", and it scarcely reaches 0-5 mm in thickness. The colour (in spirit) is greyish. The surface is hispid on account of the projecting skeletal styli. The dermal membram is a thin film, it shows a multitude of larger and smaller circular openings representing I think both oscula and pores. The skeleton. The dermal skeleton consists of single dermal spicules or of small bundles of these, stretching from the main skeleton to the surface in a more or less oblique direction. In the membrane itself there are no horizontal spicules. The main skeleton has the common construction, consisting of vertical acanthostyli with the heads placed on the substratum; the longest of the styli project beyond the surface, thus causing the hispidity of this; the skeleton is somewhat dense. At the base there is an amount of spongin, which is only slight but forms however a continuous basal lamella. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli which are more or less, generally only slightly, curved; they are thickest at the base but have no distinct head, and they taper into a long apex. The larger styli are spined at the base, but the spines are not large and outwards they become smaller and gritty, and they soon disappear; the small styli are generally straight, they are spined in the whole length, and the spines are relatively larger than in the long styli. The styli vary much in size, but there are no separated groups. The length is 0-12 — 0-65 ,m' and the thickness at the base o-oi — 0^024 mm. 2. The dermal spicules are of a characteristic shape and may best be termed oxytoruota; they are rather thick and much thickened about the middle, so that the}- are strongly fusiform; they taper towards each end, one end is tornote-shaped, or sometimes more rounded, and terminates in a little mucro, the other end is of an oxeote shape, tapering some- what evenly, but the outermost point is generally short; in some cases this latter end is so short pointed and has such a shape that the spicule might be termed a tornote. The spicules are often somewhat curved near the short pointed end. The length is o-22 — o-268mm, and the diameter in the middle is 0-008 — o-oi7n,m. b. Microsclera are of three forms, chelae of two forms and sigmata; the cheke are ordinary chelae arcuatse and peculiar chelae. 1. The ordinary chelae arcuatae have an evenly curved shaft, the alse are somewhat claw-shaped triangular, the tooth elliptical; the length is o-02i— 0-025 ram and the thickness of the shaft about o-oo2mm. 2. The peculiar chelae are spicules, which are somewhat difficult to understand; they consist of a curved shaft the ends of which ai little dilated and from this dilatation a few processes are produced; the processes may be of different number and differently, often quite irregularly arranged, but generally there are two large: processes at the end of the dilated part, and behind these two others, generally smaller processes; it is probable that the two larger processes answer to a cleft tooth, and the other small processes to alae, but this it is for the present not possible to decide with certainty; on the other hand 1 consider it .is certain, that the spicule is a chela and not a sigma. In spite of the number of processes at each end I think however, that it cannot at all be considered as an ancora; the whole shape of the dilated end-parts seems to me to point towards a chela. The length of this spicule is 0021— 0-026mm and the thickness of the shaft is about o-oo28mm. 3. The sigmata arc of a very characteristic shape, they are rather large but exceedingly fine, generally they are strongly curved in the middle and the ,uuis have a hook-formed bend at the end; sometimes they are more evenly curved; they are more or less contorted. IOO PORIFERA. III. They vary somewhat in size, the length from one hook to the other is 0-028 — 0051 mm and the thickness about o-ooio""". The microsclera are especially found in the dermal membrane, the ordinary chelas and the sigmata are however also seen throughout the tissue. As I have seen a preparation of the type-specimen, kindly sent to me from Professor Top- sent, the determination is certain; as will be seen the shape and measurements of the spicules agree very well, only the dermal spicules are different, but I think that Topsent's figure and measure- ments are taken from non-typical spicules; the few dermal spicules present in the preparation sent to me quite agreed with my figure (FIX, fig. 3 b) and were measured to o-26mm in length with a diameter of 0-017 mm. Locality: Station 25, the Davis Strait 630 30' Lat. N., 540 25' Long. W., depth 582 fathoms. One specimen. Geogr. distr. Topsent (I.e.) has the species from 37°55'Lat. N., 25°24'L,ong. W., depth 465 fathoms. 44. H. tenuisigma n. sp. PI. X, Fig. 4. Iucrusting ; surface smooth. Spicuta: megasclera ; the skeletal spicules acanthostyli with a round head, divided into two groups, large, only spined below, o-jo — o-Sj""", small, entirely spined, o-ng — o-i6""": the dermal spicules long strongyla o-j2 — 0-42 """ ; microsclera only sigmata which are large, but thin, o-oS'j—o-i2""". Of this interesting species we have two specimens, one growing on an Asiartc-sheW together with // levis, the other growing on a small Saxicava together with H. Koehleri and H. procumbens. The greatest extent to which the species reaches is about 10 mm, and the thickness is at most o-6mm. The colour (in spirit) is brownish red. The surface seems, when the sponge is undamaged, to be smooth. The dermal membrane is a thin film. Oscula and pores were not observed. The skeleton. The dermal skeleton consists of bundles of dermal spicules which stretch from the skeleton below to the surface, they thus lie between the apical parts of the long skeletal spicules; the spicules in the bundles are more or less penicillately spread outwards; the bundles are sometimes rather large, consisting of many spicules. The main skeleton is arranged as usual and consists of vertical acanthostyli, the longest of which stretch to the surface; at the base there is a small amount of spongin. Sp/cula: a. Megasclera. 1. The skeletal spicules are acanthostyli which are divided into two groups, large and small; the large styli are straight or, generally, slightly curved near the base; they have a round, more or less swollen head and taper into a long and fine apex which generally is a little more abruptly pointed outermost; the head-swelling is beset with medium sized, blunt spines, and a short basal part has small spines, the rest of the style is smooth. The small styli are generally straight, they have a round head-swelling which is however less distinct than in the large styli, it is likewise beset with blunt spines, and the styli are spined in the whole or nearly the whole length, but the spines are dispersed outwards. The length of the large acanthostyli is about 0-30 — 0-83 ram; they vary considerably in thickness from 0-020— 0-029""" allfl tn^s nas n0 relation to their length, the PORIFERA. III. ,,,, longest being often thin; the small styli have a length of 0-119— o-i6mm and a diameter at the head of o-02imm. The large styli are generally in size nearest the greatest length, the shorter of them, which are nearly intermediate between the large and the small, being ran-. 2. The dermal spicules are long and straight strongyla, sometimes one end, and sometimes both may be slightly swollen, in the latter ease the spicule approaching to a tylote; they are as a rule slightly polytylote. The length is CV32 — o-42mm and the diameter 0-005— 0-007 mm. Some fine developmental stages were found which were mouactinal. b. Microsclera are of one form, sigmata, which are rather curious; they are large but exceedingly thin, and they are more or less contorted up to a quarter of a turn, otherwise they are of the common shape. The length is 0-084 — o-i2mm and the thickness crooi4n'm. The sigmata occur through the whole tissue but are especially numerous at the surface. Locality: Station 9, 640 18' Lat N., 27° 00' Long. W., depth 295 fathoms; station 98, 650 38' Lat. X„ 260 27' Long. W., depth 138 fathoms. Both localities lie in the Denmark Strait. 45. H. Dujardinii Bow. PL X, Fig. 5. 1866. Hymeniacidon Dujardinii Bowerbank, Mon. Brit. Spoug. II, 224, 38. 1867. Halisarca Dujardinii. Gray, Proc. Zool. Soc. 1867, 520. 1874. Hymeniacidon Dujardinii Bowerbank, 1. c. Ill, 95. PI. XXXVIII, figs. 1—4. 1882. Bowerbank, Norman, ibid. IV, 92, 48. 1888. Dendoryx Dujardini, Topsent, Arch, de Zool. exp. et gen. 2, V bis, 115, PI. VI, fig. 3, 12, 13 c. 1890. — — . Topsent, Mem. de la Soc. Zool. de Fr. Ill, 201. 1891. — , Topsent, Arch, de Zool. exp. et gen. 2, IX, 528. 1892. . Topsent, Resultats des camp, scieut. du Prince de Monaco, Fasc II, 99. 1892. Myxilla radiata Bow. Topsent, (partim, the last passage), ibid. 109. 1894. Leptosia Dujardini, Topsent, Mem. de la Soc. Zool. de Fr., VII, 37. 1896. — — , Topsent, ibid. IX, 123. 1896. — — , Topsent, Resultats scieut. de la camp, du "Caudan", 275. 1 901. — — , Topsent, Arch, de Zool. exp. et gen. 3, IX, 353. 1904. — , Topsent, Resultats des camp, scient. du Prince de Monaco, Fasc. XXV, 185, PI. I, fig. 5. 1909. Hymedesmia Dujardinii, Lundbeck. Meddel. om Gronl. XXIX, 1 1 1 Tncrusting; surface smooth; pore-sieves scattered on the surface. Spicula: megasclera; the skeletal spicules acanthostyli with a globular, more or less marked head, s pined in the n 63° 3°' Lat. N., 540 25' Long. W., depth 582 fathoms; station 27, 64° 54' Lat. N., 55° 10' Long. W., depth 393 fathoms; station 28, 650 14' Lat. N., 55° 42' Long. W., depth 420 fathoms; station 35, 65 [6' Lat N., 550 05' Long. W., depth 362 fathoms; further it has been taken at East Greenland, Forsblads Fjord, depth 50—90 fathoms (The Amdrup-Expedition 1900), and at the Faroe Islands, depth 30 fathoms i'1'h. Mortensen). The localities are situated in the Davis Strait, at blast Greenland, the Eastern coast of Iceland and the Faroe Islands. Geogr. distr. II. Dujardinii was hitherto recorded from the Eastern roasts of Britain and lie- land (Bowerbank); from the French coast of the Channel (Luc, Roscoff, Calvados) (Topsent), the Bay of Gascogne, depth 95 fathoms (Topsent), the coast of Provence at Ciotat (Topsent), at the \ ores in depths of 69 and 28 fathoms, at 460 47' Lat. N., 6oc iz' Long. W., depth 7.? fathoms (Topsent), finally at io4 PORIFERA. III. the coasts of North Africa, in the Bay of Gabes and at la Calle (Topsent). The species is thus hitherto known from 65 J to 340 Lat. N., and between 6o° Long. W. and 10° Long. E. As to the depth some of the specimens of the Ingolf Expedition are taken in considerably greater depths than those from which it was known hitherto; the greatest depth recorded was 95 fathoms, while it was taken by the Ingolf Expedition in depths down to 582 fathoms. Its bathymetrical range as known now is in all from the very coast even above low-water mark (Bowerbank) down to 582 fathoms. Remarks: If the rules of nomenclature were adhered to strictly, the present species should have a new name, as it is not identical with the well known Halisarca Dujardinii Johnst. Bower- bank thought, when he examined the present species, that Johnston had overlooked the spicules, and he identified it therefore with Dujardinii. Already Schmidt has noted (Zweites Suppl. zu den Spongien des adriat. Meer. 1866, 16) that this must be erroneous. Gray however in 1867 followed (1. c.) Bowerbank. Topsent in 1888 (I.e.) placed the species in the genus Dendoryx, and referred it later correctly to his genus Leptosia, but he did not alter its name, which should properly have been done, since Bowerbank's determination was erroneous. As the species is well known now under the name Dujardinii I shall however make no change. 46. H. primitiva n. sp. PI. X, Fig. 6. Incrusting ; surface smooth. Spicula: megasclera; the skeletal spicules acantJiostyli with a slight head-stvclling, entirely spincd or the larger with a smooth apical part, o-/ip — o-jj""", not divided into two groups; the dermal spicules strongyla, slightly polytylote, owpd — o-28mm. No microsclera. This species grows incrusting on shells of Brachiopods, mussels and barnacles; it has a greatest extent of about 20mra, the thickness is about 0-5 mm. The colour (in spirit) varies between dark yellowish and brown. The surface is smooth. The dermal membrane is a distinct but thin film; it was on my specimens often destroyed to a high degree. Some canals are seen shining through the membrane, and some oscula are present as circular openings not elevated over the level of the surface. The skeleton. The dermal skeleton consists of bundles or quite short fibres stretching from the main skeleton, often almost from the base, to the dermal membrane; the spicules in the bundles are penicillately spread towards the membrane and support it, but they do not pierce it. The mem- brane itself is not provided with spicules or at all events only with some few, lying singly and scattered; only around the oscula the structure is different; short fibres appear here in the membrane, stellately arranged all round the opening, towards which they unite in such a way, that the opening is surrounded by radiately arranged, but not dense-lying single spicules. The main skeleton is of the ordinary arrangement, the vertical acanthostyli are somewhat densely placed; the longest of them reach just to the dermal membrane. There is a considerable amount of spongin at the base, forming a more or less continuous basal layer. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli, which have only a slight head-swelling; they are straight or, when longer, slightly curved near the base; they are somewhat densely spined with spines of medium size; in the longer spicules the spines are small and scattered PORIFKRA. III. lQr towards the apex, and a shorter or longer part may be smooth. The stvli vary much in size but they are not divided into two groups. The length is 0-119— 0,35mm aU(l l'K' diameter at the base is 0-014— 0-027""". The styli may vary somewhat in different individuals, in some they are more robust and more coarsely spined than in others, and at the same time the smooth part towards the point is wanting or small. Also with regard to the size there is some variation, the greatest length being in some individuals 0-27™"'. 2. The dermal spicules are straight or slightly curved, cylindrical strongyla; they are slightly but distinctly polytylote and the ends are generally very slightly swollen, the swellings being as a rule scarcely perceptible. The length is in all 0-196— o-28mm, but there may be- some variation between the individuals; the diameter is 0-0028 — 0-005 "'"'• 'J- Mtcrosclera are not present This species is characterised towards //. Dujardi>iii by the size and shape of the acanthostvli and by the polytylote dermal strongyla. Locality: Station 6, 630 43' Lat. N., 14' 34' Long. W., depth 90 fathoms; station 2-j-jj""". No microsclera. Of this species we have a couple of specimens growing on a branching Bryozoon, and one growing on a stone; the latter specimen is incrusting in the common way, but the specimens growing on the Bryozoon quite envelop the branches of this, and they also extend between the branches, filling the interspaces with their body, which however in these places is thin and plate-shaped. The greatest extent of the species is about 35""", and the thickness of the incrustation may reach 1-5 ' . The colour (in spirit) is whitish or yellowish white. The surface is smooth, without projecting spicules, it bears a number, smaller or greater, of conical papilla;; these papillae are highly compressed and are generally lying quite down towards the surface with a flat side turned upwards, and the arrangement is then such, that the opening, which lies in reality in the summit, comes to lie at the summit oi the side of the papilla, which is turned upwards. The dermal membrane is a thin and separable film; it has no skeleton proper, but the tissue lying below it, and which has horizontal fibres, is liable to be separated off together with the membrane, the whole thus giving the impression of a thick and solid membrane. Oscu/a and pores are certainly situated on the papillae mentioned; most of these show a rather large opening at the summit, while some others are more pointed and conical with a small IOS PORIFERA. III. opening; I have not seen pore-sieves but the papillae with the large opening are in all probability pore-papiike, the others being oscular papillae, the facts being thus as in H. verrucosa. The skeleton. The dermal skeleton; the skeleton formed by the dermal spicules is by far the most developed and it occupies nearly the whole body of the sponge; it consists of fibres which stretch from the main skeleton or quite from the base and obliquely towards the surface, but they run generally so obliquely, that they are for long distances more or less parallel with the surface, and the skeleton is on the whole rather irregular on account of the manner in which the sponge grows; the fibres are somewhat numerous and they are also rather strong, of a thickness up to cri2mra. The fibres stretch horizontally just below the dermal membrane and terminate in it, but there are no spicules proper to the membrane. The fibres lying below the membrane run together at the base of the oscular and pore-cones and continue up in the wall of these, forming thus a skeleton which consists of densely placed parallel spicules with the ends towards the opening of the cone. The main skeleton is somewhat weakly developed and consists as usual of acanthostyli with the heads based on the sub- stratum, but the styli are much scattered and not numerous. At the heads of the acanthostyli there is a very small amount of spongiu. Spicnla: a. Megasclcra. i. The skeletal spicules are acanthostyli which are divided into two well separated groups, large and small. The large styli are straight or slightly curved, the head is small or not at all developed; they taper evenly outwards but at the end they are abruptly pointed with a short point; they are spined only on the basal part at most in the lower half part; most of the spines, especially those on the head, are somewhat strong. The length is 0-30 — 0-417 mm and the diameter of the head 0'0i8— 0'022mm. The small styli are straight and spined in the whole length, but the spines are small and scattered in the outer part, otherwise they are relatively robust; these styli are somewhat uniform in size, the length being 0-107— o-i3mm and the diameter of the head 0014 — 0-019 mm. 2. The dermal spicules are long and straight strongyla with one end thicker than the other; they may be slightly polytylote; the ends may sometimes be very slightly swollen, especially in the thinner strongyla. The length is 0-33— 0-45 mm and the diameter 0006— o-oio""1'. Microsclera are not present. This species is interesting in a certain respect; it resembles to a very high degree one of the species with chelae, viz. H. stylata; the only differences, besides the want of the chelae, are that both the styli and the dermal spicules are slightly smaller in the present species than in stylata, but this is of no specific value; otherwise the growth, the surface with its papillae, the structure of the dermal membrane, the arrangement of the skeleton and the shape of both kinds of spicules agree very well in the two species, and if it were not for the difference in the possession and non-possession of chelae, and the difference in the structure of the dermal membrane, to which the want of the chelae seems to give rise, I should not hesitate in uniting them. As however I have otherwise never found, that the same species may be with or without cheke, I think it necessary to consider the present species as specifically distinct from //. stylata.1) It is to be remarked, that the specimens of both species are ') To be sure Topseut has described (Resultats du Voy. du S. Y. Belgica, Spongiaires, 1901, 18.) a species without sigmata as Ussodendoryx spongiosa R. and D. var. asigma/a, and in the same place the author strongly advocates the view that sponge-species are capable of varying in such a way, that they may want a form of microsclera otherwise present in the species,' 1 cannot at all agree with Topsent in this view, and with regard to the examples he mentions ( Hamcuantha John- sotit, Desmacella Peachii) 1 have proved (The Ingolf Exp. VI, 1. 1902) that the supposed varieties are distinct species, and with regard to H.Johnsoni Topsent has himself in his work from 1904 admitted the specific validity of his former varieties. PORIIF.RA. III. IOq in a good state, and they have especially the dermal membrane undamaged, and further it must be noted, that the chelae in stylata are numerous and form a layer in the dermal membrane. Should the two species be considered as identical, it must be from the point of view, that the specimens of dermata were abnormal, but there is otherwise nothing to indicate such a state. Now one fact is very interesting, and it is that H. stylata is from the cold area (station 113, bottom temperature -Mc o C), while the present species is from bottom with positive temperature. It is not for the first time that very nearly related, but distinct species are found one on negative the other on positive bottom (e.g. Gelliodes plexa and consimilis, The Danish Ingolf Exp. VI, 1; Asbestoplunia pennatula and bihamatifera. Cladorhiza abyssicola and gelida, Lissodaidoryx co»iplicata and vidua; ibid. VI, 2.). Locality: Station 2, 63° 04' Lat. X., 90 22' Long. W.. depth 262 fathoms; Forsblads Fjord in East Greenland, depth 50—90 fathoms (The Amdrup Expedition 1900). The localities lie at E Greenland and West of the Faroe Islands. 50. H. tornotata n. sp. PI. Ill, Fig. 18, PL XI, Fig. 2. Incrusting; surface hispid. Spicula: megasclera; flic skeletal spicules acanthostyli with a more or less pronounced head, entirely spined but in the longer the spines very small outwards, o-ioj — O'ji""", not distinctly divided into two groups; the dermal spicules long- toruofa , generally with microspined end-parts, crj2 — o-jj""". No microsclera. This species is represented by four specimens, three growing on shell-fragments, the fourth on a Brachiopod; the former are rather small crusts while the latter covers the greatest part of the Brachiopod shell and has thus an extent of 20mm. The small specimens are about o-jmm thick, while the larger one reaches to a thickness of about imm; this comparatively great thickness is reached on account of a special development of the dermal skeleton as mentioned below. The colour (in spirit) is light brown to brown. The surface is densely hispid from projecting dermal spicules; the small specimens are much more hispid than the large. The dermal membrane is inconspicuous and not separable. Oscula and pores were not observed. The skeleton. The dermal skeleton consists of large bundles of dermal spicules which stretch from the main skeleton to the surface, the spicules in the bundles are penicillately spread outwards and project beyond the surface for a rather long distance; seen from above the projecting spicules are almost stellately arranged. Such is the construction of the dermal skeleton in the small specimens, but in the large specimen the facts are somewhat otherwise; the dermal spicules are here more numerous and they are somewhat strongly interwoven, forming a dense and thick layer, and apparently lying without any order; only outermost they are arranged somewhat parallel, with the p ting outwards; this layer may reach to a thickness of cr8 . The difference in the development of the dermal skeleton in this species i>. as will he seen, about the same as ma\ also occur in Ff. Dujara The main skeleton is of typical construction, consisting of vertical acanthostyli with the heads on the substratum; they are placed rather densely. At the base there is an amount of spongin. 1IO PORIFERA. III. Spicula: a. Megasclcra. i. The skeletal spicules are acanthostyli which are not divided into two groups, in so far as intermediate forms occur, but as these are somewhat rare, the styli give the impression of falling into two groups; the large styli are straight or very slightly curved, they have a roundish head with moderately sized spines, the shaft has small spines which become quite gritty outwards; the small styli are generally straight, the head is less pronounced than in the large, the spines are larger and often distinctly reclined. The length of the styli is in all 0-107— 0-31™'" anc^ the diameter at the head 0-014— o-02imm. 2- The dermal spicules are long, straight, or somewhat, often irregularly, curved tornota; they are thickest in the middle and thus more or less fusiform; they show a curious feature, the end-parts being generally, but not always, somewhat roughened or micro- spined. The length is 0-32— 0-47 mm and the diameter in the middle 0-004 — 0-007 mm. Microsclcra are not present. Locality: Station 81, 6r°44' Lat.N., 270 oo' Long.W., depth 485 fathoms; station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; East of the Faroe Islands, depth 160 fathoms. The localities lie in the Denmark Strait, South-west of Iceland and at the Faroe Islands. 51. H. mucronella n. sp. PL III, Fig. 19, PL XI, Fig. 3. Incrusting, but of somewhat massive appearance ; surface hispid. The dermal skeleton strongly developed, the mam skeleton weak. Spicula: megasclcra; the skeletal spicules acanthostyli divided into two groups, large with a very small head, only spined below, O'jo — 0'6j""". small, with a more distinct hiad, and entirely spined, o-ij — o-jj8""" ; the dermal spicules tornota with one end with a mucro, o-jS — 0-396""". No microsclcra. Of this species we have only one specimen which grows on a fragment of a Sipho; the sponge is of a somewhat massive shape as it does not incrust the shell-fragment but is only fixed on it and is for the rest somewhat filled with bottom material; it thus shows a growth similar to that in H.grandis, though it is much less filled with foreign particles. On account of large cavities in the sponge the consistency is somewhat bladder-like. The specimen has an extent of 17""" and a height of about 9mm. The colour (in spirit) is dark greyish brown. The surface is strongly and densely hispid from projecting dermal spicules. Oscula and pores were not observed. The skeleton. The dermal skeleton: the skeleton formed of the dermal spicules is strongly developed and occupies the greatest part of the sponge; it consists of fibres running everywhere but chiefly in the direction from the base, or else from some part of the main skeleton, towards the surface, the fibres may thus attain a relatively great length; in the dermal membrane the spicules form peuicillately spread bundles, the spicules of which pierce the membrane; seen from above the spicules in the bundles appear almost stellately arranged; in places where the membrane stretches over the large cavities, fibres pass horizontally just below it, and the bundles seem here to originate from these fibres. The sponge-body has, as said, many large cavities and the fibres are found therefore in the parts of the tissue separating these cavities. The main skeleton is not much developed; it consists of acanthostyli based with their heads partly on the shell at the base of the PORIFKRA. III. II I sponge and partly on the imbedded foreign particles, such as large sponge-spicules, gravel and the like, which particles must be considered therefore also as substratum for the sponge; the acanthostyli placed on the imbedded material may point in every direction, and the main skeleton is, according to the manner of growth of the sponge, quite irregular. At the head of each acanthostyle there is a small, but distinctly observable amount of spongin. Spicule: a. Megasclera. i. The skeletal spicules are acanthostyli, divided into two groups, large and small; the large styli are straight or slightly curved near the base; the head is very small or almost quite absent, the basal part has some small or moderately sized spines, but only for a short distance, the remainder of the shaft being smooth or slightly and imperceptibly gritty. The length is 0-40 — 0-65 mm and the diameter at the base 0-017 — o'oai'1"". The small acanthostyli generally straight with a slight but distinct head-swelling; they are densely spined in the whole length, the spines on the head being the largest. The length is 0-14 — o-i78m,! and the diameter of the head is o-oij""1'. 2. The dermal spicules are tornota but of a characteristic shape; one end is pointed in the way common for tornota and not very short, the other end is shorter and more roundish pointed and has a very distinct mucro; the latter end is somewhat thicker than the former; the tornota are long, straight or nearly so and slightly thicker in the middle than towards the ends. The length is 0-38 — o'596n,m and the diameter in the middle 0-005— o-on mn'; ine intermediate sizes are by far the most common. Microsclera are not present. Locality: At East Greenland, 700 32' Lat. N., 8° 10' Long. \V., depth 470 fathoms (The Ryder Expedition 1891—92). Above I have described 51 species of Hymedesmia of which only seven arc determined as previously described species; these are: H. A\oc/ilcri Tops., dcch/M Bow., baculifera Tops., crux O. Schmidt. filifera O. Schmidt, mucronata Tops., and Dujardiuii Bow. I have tried to find out the other previously described species, and I think that at all events most of them are enumerated in the following list: 1866. H. zetlandica Bow. Mon. Brit. Spoug. II, 152, III, PI. XXI. figs. 1—7. « — paupcrtas Bow. ibid., II, 223, III, PI. XXXV, fig. 4—8 (Hymemaczdi 1875. — vidua O. Schmidt. Jahresber. der Comni. zur wissensch. Unters. der deutsch. Meere in Kiel fur 1872—73, 120. {Spirastrella); Thiele, Arch, fur Naturgesch. 1903, I. 303. Tat. XXI, Fig. 27. 1882. — Peachii Bow. 1. c. IV, 64. PI. XIII, figs. 5-12. 1885. — mammilaris Frstdt Kgl. Sv. Vetensk. Akad. Handl. 21, 6, 32, Tax-. Ill, Fig. 3 a— h. {Hasta, Thiele, Arch, fur Naturgesch. 1903, I, 3S9, Tat. XXI, Fig. 22 a— d. 1887. — pustula Frstdt Ofvers. Kgl. Vet. Akad. Forh. [887, No. 1, 27, (Espcria). 1903. — prostrala Thiele, Abhandl. Senckenb. nat. (resell. XXV, 055, Tal. XXVIII, Fig - norvegica Thiele, Arch, fur Naturgesch. 1903, I, 390, Taf. XXI, Fig. 23 a c. (perhaps a A 1904. -- mutabilis Tops. Resultats des cam]), scient du Prince de Monaco, Fasc. XXV, [66, PI. XI\, fig. 3. [Hymeraphia). — Schmidti Tops, ibid., 189, PI. XV, fig. 9. (Leptosia). II2 PORIFERA. III. 1904. H. rap/iigena Tops. Resultats des camp, scient du Prince de Monaco, Fasc. XXV, 192, PL XV, fig. 7. (Leptosia). — obtusata Tops, ibid., 193, PL XV, fig. 6. (Leptosia). — acerata Tops, ibid., 193, PL XV, fig. 5. [Leptosia). 1905. — tenuissima Dendy, Rep. on the Pearl Oyster Fishery of the Gulf of Manaar, III, 169, PL XI, fig. 5. (Myxilla). — areolata Thiele, Zool. Jahrb. 1905, 452, Taf. 31, Fig. 23, 68 a — d. 1906. — lancifera Tops. Bull, du Mus. d'hist. nat. 560. (Leptosia). The number of species seems thus at present to be about seventy; this is already a large number and there is reason to believe, that many more species will be described in the future. Earlier Expeditions paid often but little attention to the insignificant crusts, which is the shape of most Hymedcsmia species; it is first in the work of Topsent from 1904 that a greater number of incrusting species of various genera is recorded, and the author says expressly, that this fact is due to the care with which he examined stones, corals etc. brought home. The Ingolf Expedition laid the greatest stress on procuring all small and incrusting sponges, and hence our material is very rich. Under these circumstances when the number of species must be expected to increase in the future to some degree, it is of the greatest importance, that the new species are described thoroughly, and the spicules ought always to be figured, so that the affinities of the species can be judged. I shall therefore try to give here an analytical table of all the above enumerated species; this table is of course only an attempt, and I do not think that a species can be definitely determined only by its aid, but I think however it may be useful. Table of the Species of Hymedesmia. 1. Microsclera present 2. — No microsclera 59. 2. Microsclera only chelae arcuatse (sometimes transformed to spiued rods) 3. Microsclera chelae arcuatae together with sigmata, or sigmata alone or rhaphides 45. 3. The chelae of common shape 4. — The chelae spined or quite transformed 43. 4. The dermal spicules genuine strongyla 5. The dermal spicules of other forms, at all events not quite genuine strongyla. 21. 5. The acanthostyli not divided into two groups 6. The acanthostyli somewhat distinctly divided into two groups 13. 6. The dermal strongyla more or less distinctly polytylote 7. — The dermal strongyla not, or not distinctly, polytylote 10. 7. The chela; somewhat strongly curved, 0*028— 0-050 mm, the acanthostyli with blunt spines on the head Koehleri Tops. — The chelae less strongly curved 8. 8. The chelae with somewhat long, free alse, 0-045— 0-054 mm lacera — The chelae smaller, somewhat like palmate chelae 9. 9. The acanthostyli strongly spined, especially at the head, chelae 0-033— 0-038 mm • storea — The acanthostyli less strongly spined, chelae o-028mm lamina PORIFERA III. j j. 10. Surface with low warts or long papillae 1 1. — Surface simple 12. 11. Surface with low warts, dermal strong via long and straight verrucosa — Surface with long papillae, dermal strongyla robust with a double curvature .. . filifera Schmidt 12. The acanthostyli only spined on the head norvegica Thick:. The acanthostyli spined in the lower half part mollis 13. The chelae strongly, nearly semicircularly curved curvichela — The chelae less strongly curved 14. 14. The dermal spicules polytylote, chelae large, 0-052 — 0-064 mm, the end-parts some- what recurved rugosa — The dermal spicules not polytylote, chelae smaller 15. 15. The acanthostyli strongly spined in the whole length splenium — The acanthostyli not entirely spined id. 16. The large acanthostyli spined towards the apex, chelae 0-032 — 0-037""", the free part of the shaft about one third of the length tenuicula — The large acanthostyli at most spined in the lower half part 17. 17. The small acanthostyli distinctly curved 18. — The small acanthostyli straight 19. 18. The acanthostyli reaching to o-65mm, chelae somewhat strongly curved, 0-035- o"044mm similis — The acanthostyli reaching to 0-42 mm, chelae less curved, 0-037""" putt per las Bow. 19. The acanthostyli long, reaching to 0-95 mm, the dermal spicules slightly tending towards tornota nummulus — The acanthostyli shorter, the dermal spicules pure strongyla 20. 20. The acanthostyli reaching to 0-63 mm, the dermal strongyla 0-35—0-52""", surface with papillae sly la fa — The acanthostyli reaching to 0-38 ram, the dermal strongyla 0-26 — 0-32 n,m, surface simple dubia 21. The dermal spicules diactinal (at all events not distinctly monactinal) 22. — The dermal spicules monactinal 42. 22. The dermal spicules tornota 23. — The dermal spicules oxea or tylota 32. 23. The dermal spicules centrotylote tornota land/era Tops. — The dermal spicules not centrotylote 24. 24. The tornota with unequal ends — The tornote with equal ends 25. The large acanthostyli only spined at the base, 0-24 """, chelae o-oiS""" prostrata Thick-. — The large acanthostyli a little more spined, 0-45""", chela: 003""" Peachii Bow. 26. The large acanthostyli spined in about the whole length — The large acanthostyli spined only near the base 31, 27. The chelae of ordinary shape — The chelae extraordinarily flat platychcla 28. Surface with papillae, tornota 0-36""", cliche 0-024 """ ma mm 1 liar is Frstdt — Surface simple 29. The acanthostyli reaching to 0-53 """, the tornota 017 o-22mm, cliche with slightly recurved end-parts 0-021 — 0-054""" perforata The acanthostyli not reaching over o^""" 3a The [ngolf-Expedition. VI. 3 U4 PORIFERA. III. 30. The acanthostyli reaching to 0-35 mm, tornota 0-22 — 0-32 mra, chelae somewhat strongly curved 0-024— 0-038 mm procumbens — The acanthostyli reaching to 0-298 mm, tornota o-i6 — o-i7mm, chelae less strongly curved, 0-041—0-052 mm clavigcra 31. Surface with papillae, acanthostyli reaching to o-59mm, tornota 0-32— 0-50 mm, chelae somewhat palmate-like, 0-025— o-030mm basispinosa — Surface simple, acanthostyli reaching to 0-92 mm, tornota 0-23 — o-28mm, chelae of ordinary shape, 0-025— 0-045 mm lo/igistylus 32. Dermal spicules oxea 33. — Dermal spicules tylota 35. 33. The acanthostyli almost entirely spined, chelae 0-025 mm areolata Thiele. — The acanthostyli only spined near the base 34. 34. The acanthostyli reaching to ri9mm, chelae 0-034— o-04omm occulta Bow. The acanthostyli reaching to 0-65 mm, chelae strongly curved, 0-028— 0-037 mm .... simillima 35. The acanthostyli almost smooth, only slightly spined at the base, chelae 0-045 — 0-052 mm IcFvisfylus — The acanthostyli more spined, often entirely 36. 36. The acanthostyli divided into two groups bractea. — The acanthostyli not divided into two groups 37. 37. The acanthostyli varying in size, reaching to 0-25 mm 38. — The acanthostyli rather uniform in size, not reaching over 0-13 mm 39. 38. The acanthostyli somewhat robustly spined, dermal tylota not or only slightly polytylote baculifera Tops. — The acanthostyli more finely spined, dermal tylota polytylote levis 39. The acanthostyli truncate at the point trunea&a — The acanthostyli not truncate at the point 40. 40. The tylota distinctly polytylote, 0-148 mm tenuissima Dend. The tylota not, or not conspicuously polytylote, length 0-19 ram or more 41. 41. The acanthostyli without any neck-shaped constriction at the base, the tylota 0-19 — 0-23 mm Bowcrbanki The acanthostyli with a neck-shaped constriction at the base, the tylota 0-30— 0-40 mm latrunculioides 42. The dermal styli polytylote, the acanthostyli not divided into two groups,' chelae 0-040— o-050mm irregularis The dermal styli not polytylote, the acanthostyli divided into two groups, chelae 0-023 — 0-035 mm proximo 43. The chelae transformed to spined rods vidua Schmidt. The chelae less transformed, more chel-shaped, or only spined 44. 44. The chelae of normal shape but spined crux Schmidt. The chelae more transformed, somewhat asteriform acnigma 45. Microsclera chelae and sigmata 46. - Among the microsclera no chelae 58. 46. Sigmata only of one form 47. Sigmata of two forms 56. 47. The acanthostyli of uniform size, about 0-13™™, strongly spined, sigmata in bundles zctlandica Bow. The acanthostyli longer, sigmata not in bundles 48. I'ORII'ERA. III. US 48. The chelae spined and transformed Schmidti Tops. — The chelae not spined 49. 49. The chelae of two forms, ordinary and peculiar mucronata Tops. — The chelae only of one form 50. 50. Sigmata rather large, not below 0-028 """ and generally much larger, surface with papillae or warts 51. — Sigmata small, not above 0-020""", surface simple 54. 51. Surface with warts, sigmata about o-i""", chelae of two forms, large 0-025 . small o-oi2mm fustula Frstdt — Surface with long, cylindrical papillae, chelae of one form 52. 52. Sigmata nearly plane, dermal tylota 0-29—0-38"'"', sigmata 0-058— 0-075 """ trichoma — Sigmata not plane 53. 53. The acanthostyli 0-41 — 0-75""", dermal tylota 0-48— o-8oram, sigmata 0-031—0-096""" grandis — The acanthostyli o-i 1 — 0-31""", dermal tylota 0-26 — 0-41""", sigmata 0-028— 0-050 mm digitata 54. The dermal spicules thin styli, sigmata circularly curved, nearly plane, 0-014 — 0-017"'" pugio — The dermal spicules not styli 55. 55. The dermal spicules tornota 0-15—0-19""", sigmata 0-014— 0-017"'"' consanguinea — The dermal spicules tylota 0-23 — 0-28""", sigmata 0-020""" mutabilis Tops. 56. The large sigmata somewhat band-shaped, peculiarly curved, the small sigmata plane cultrisigma — Both the large and small sigmata of ordinary shape 57. 57. The large sigmata 0-18-0-208"'"', the small 0-06— 0-089'""' macrosigma — The large sigmata contorted, 0-021— 0-028 mm, the small sigmata plane 0-014""". • planca 58. Microsclera only sigmata tenuisigma — Microsclera only rhaphides rhaphigena Tops. 59. Dermal spicules strongyla or tylota 60. — Dermal spicules tornota 65. 60. The acanthostyli truncate at the point obtusata Tops. — The acanthostyli not truncate at the point 61. 61. The acanthostyli generally with a globular head, 0-083 — 0-22'""', the dermal spicules strongyla to subtylota and there are always subtylota present Dujardinii Bow. — Dermal spicules strongyla 62. 62. The acanthostyli not divided into two groups 63. — The acanthostyli divided into two groups, the dermal spicules long, 0'33— o-45mn 63. The acanthostyli entirely spined aeqtiata — The acanthostyli with a smooth apical part 64. 64. The acanthostyli 0-11 — 0-35""", dermal strongyla polytylote, 0-149— o\:X primit — The acanthostyli o-io — o^o1""', dermal strongyla smooth or polytylote, 022 -0-298 65. The dermal tornota not polytylote, generally microspined at the end-parts tornotata — The dermal tornota not with spined ends 66. The acanthostyli 0-14—0-38""", the tornota slightly polytylote acerata Tops. — The acanthostyli 0-14—0-65""", divided into two groups, the tornota with a inu at one end mucronclla Four species in Bowerbank's Monograph could perhaps also be taken into consideration, viz Hymeniacidon perarmatus (III, PI. XXXI, Eigs. 11 [6) which would in such a case perhaps be related to //. occulta and simillima; but it is possible that the species is an Ectyodoryx. Hymcdesmia pansa 15* u6 PORIFERA. III. (IV, PL I, figs, i — 4) has long, monactinal dermal spicules; it seems to be a Hymcdcsmia or an Eurypon. Hymedesmia pilata (IV, 59, PL II, figs. 1—4), which seems to have no dermal spicules and only sigmata for microsclera, is I think an Eurypon. Finally Hymedesmia pulchella (IV, 61, PL II, figs. 5 — 8) seems to be likewise an Eurypon. Hymcniacidon paupertas Bow. (Ill, PL XXXVII, figs. 4 — 8) I have included in the above table as I take it to be a Hymedesmia, and I think the Myxilla paupertas recorded by Topsent (1904, Fasc. XXV, 168) is another species. The Hymedesmia arcolata Thiele mentioned by Kirkpatrick (Nat. An tare. Exp. Nat. Hist. IV, PL 22, figs. 3 — 3 c) cannot I think be a Hymedesmia and must accordingly be another species. Thiele (Abhandl. Senekenb. nat. Gesell. XXV, 1903, 955) thinks that Myxilla veneta O.Schmidt is identical with fasciculata Lieberk., and is a. Hymedesmia; I have examined a specimen of Myxilla fasciculata send from Professor von Marenzeller; it is correct that the species incrusts the chitinuous tubes of Stephanoscyplius, but it has otherwise a reticulate skeleton and is no Hymedesmia ; M. veneta I do not know. Hymedesmia norvegica Thiele, which I have included in the above table, is perhaps not a Hymedesmia as it has short skeleton columns; it would thus be a Stylostichon. Hymenancora n. g. Incrusting, thin forms. The external appearance, the skeleton and the megasclera quite as in Hymedesmia ; the microsclera are ancortz which ?nay be cither ancorce spatuliferce or unguifcra •./ some- times tzvo forms of ancorce occur; to the ancorce sigmata are sometimes added, In the introduction to the second part of this work I have, in accordance with the opinions of Levi us en, advanced the view, that species with ancorae and species with chelae should not remain in the same genus, and in accordance herewith I emended the genera Desmacidon and Homoeodictya, Myxilla and Lissodendoryx, and according to the same view I have created the genera Ectyodoryx and Ectyomyxilla (Meddel. om Gronland, XXIX, 1909, 444), the first with chelae, the latter with ancorae. Also the genus Hymedesmia has hitherto included species with chelae and species with ancorae, and it is to comprise these latter species that I create the genus Hymenancora which is in all other respects similar to Hymedesmia. So far as I am avare the genus comprises at present the following species: 1892. H. Pec query i Tops. Resultats des camp, scient. du Prince de Monaco, Fasc. II, no, PL XI, fig. 8 {Myxilla). « H. minima Tops, ibid., 114, PL XI, fig. 2—3. (Hymeraphia). 1904. H. biscutclla Tops, ibid., Fasc. XXV, 191, PL XV, fig. 3. (Lcptosia). « H. umbellifera Tops. ibid. 192, PL XV, fig. 4. (Leptosia). 1905. H. laevis Thiele, Zool. Jahrbiicher, 1905, 453, Taf. 31, Fig. 69 a— f. {Hymedesmia). « H tenuissima Thiele, ibid. 454, Taf. 31, Fig. 70 a — f. {Hymedesmia). 1907. H exigua Kirkpatr. Ann. Mag. Nat. Hist. 7, XX, 273, and 1909, Nat. Autarct. Exp. IV, PL XXII, fig. 4, PL XXVI, figs. 2 a— f. (Hymedesmia). PORIKKRA. III. "7 1907. H. rufa Kirkpatr. Ann. Mag. Nat. Hist. 7, XX, 274, and 1909, Nat. Antaret. Exp. IV, PI. XXII, fig. 5, PI. XXVI, figs. 3 a — e. (flymeraphia). H. interjecta mihi H. conjungens mihi H. tenuisclcra mihi H. duplicata mihi. I do not see the slightest reason why H. minima Tops, and //. rufa Kirkpatr., both placed In- die authors in Hymcraphia, should not belong to Hymenancora. 1. H. interjecta 11. sp. PI. XI, Fig. 4. Incrusting; surface slightly hispid. Spicula: megasclera; the skeletal spicules acanthostyli without a real hcad-sivclling, spitted in the whole length, they ore divided info two groups, large o-jy — o-jy""", small 0'i-f — o-/6"""; the dermal spicules tylota or subtylota o-jo— 077""" .• mieroselera two forms. aucorcB spatulifera with three teeth, 0-025 — 0-045""", sigmata o~o6 — 0-128""". Of this species we have two specimens; one grows on a dead branch of an Oculina together with H. procumbens and specimens of Tedania, Eurypon and Latrunculia ; the other specimen, which is very small, grows on a pebble. The largest specimen is extended along the Oculina-bvanch and is therefore of a lengthy shape and has a greatest extent of 22 "Im; it is exceedingly thin. The colour (in spirit) is greyish or brownish. The surface is in the present state of the sponge slightly hispid. About the dermal membrane, pores and oscula I can say nothing. The skeleton. The dermal skeleton seems to consist of bundles and scattered spicules. The main skeleton is, so far as I could observe, constructed in the ordinary way of vertical acanthostyli placed on the substratum, but the styli are somewhat scattered and the dermal skeleton is therefore the most developed part of the whole skeleton. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli which are somewhat distinctly divided into two groups. The large styli are straight or generally somewhat curved near the base; the base is a little thickened, but there is no head-swelling present, and they taper into a long and fine apex; the styli are spined in their whole length, but the spines are only at the base of larger size, they decrease in size outwards, and the shaft and apex are only gritty; the larger spines at the base are generally curved upwards in a somewhat characteristic way. The small styli are principally of the same shape as the large, but they are often straight, and the spines are relatively larger, the head also is still less developed than in the large. The length of the large styli is 037 — o-47mm with a diameter at the base of 0'020— 0-023 mm. '^ne sma'l styli have a length of 0*14 — o*i6 and a diameter at the base of o-o20mm. 2. The dermal spicules may best be termed tylota; they are straight or very slightly curved and somewhat robust, the end-swellings are very small but how- ever always perceptible. The length is 0-30— 0-47""", and the diameter of the shaft 0007— o-oiomm. b. Mieroselera are of two forms, ancoroe spatulifene and sigmata. 1. The ancorse have a curved shaft and three elliptical teeth at each end, but the most remarkable feature is, that they have only very nS PORIFERA. III. narrow alse or these may be quite absent; by this fact these aucorae get some resemblance to arcuate cliche and it seems that they also in reality must be nearly related to these. The length of the ancorae varies much, it is 0-025— 0-045 ram, aim the thickness of the shaft is about 0-002— 0-005 mm- 2- The sigmata are of ordinary shape and more or less contorted; they have a length of 006 — o-i28n,m and a thickness of 0-004 — 0-0065 nm>. The microsclera seem to occur through the whole tissue. Locality: Station 54, South of Iceland, 630 08' Lat. N., 150 40' Long. W., depth 691 fathoms; station 98, in the Denmark Strait, 650 38' Lat N., 260 27' Long. W., depth 138 fathoms. Remarks: As said the ancorse in this species seem to be nearly related to the chelae arcuatae on account of the very narrow and, so far as I could see, sometimes quite wanting alse, but they are however true ancorae. In Part II of this work p. 3 I have stated that I consider the ancorse and chelae arcuatae as nearly related spicula and as having been derived from a common original form of spicule It is well known, that the chelse arcuatae may be more or less ancora-like, but being at the same time true chelae, and many examples of this are given in the preceding descriptions. As one of the most ancora-like chelae I have examined I may note the chela in Hymedestnia Bowerbanki. The alae do not go here evenly over into the hinder side of the shaft but are somewhat incurved at the shaft, so that in a side view the "tuberculum" is seen quite surrounded by the outer contour of the ala; and so far as I could see the shaft is a little edge-like dilated towards the ends; these spicules are however true chelae. Should there be found in the genus Hymedestnia forms of micro- sclera which were intermediate between ancorae and chelae arcuatae, and this seems not impossible, it would be of great interest, and it would seem to indicate at the same time, that Hymedestnia is a genus of old origin, as already alluded to from other reasons under H. aenigma. 2. H. conjungens 11. sp. PI. XI, Fig. 5. Incrusting; surface somewhat hispid. Spicula: megasclera; the skeletal spicules acanthostyli without head-swelling, they are divided info tzvo groups, large, spined nearly in the whole length or only with a small apical part smooth. o-2g — 0-41""", small, entirely spined, 0-11—0-13""" ; the dermal spicules tylota with pointed end-swellings, 0-16 — 0-22'"'"; microsclera two forms, ancorcr spatulifcnc with three teeth, 0-022 — 0-042""". sigmata o'ojj — 0-045""". We have one specimen of this species growing on a living Peeten together with specimens of Melonanchora emphysema, Hymedestnia perforata and procumbens, a Crclla, an Eurypon and a Plocamia. It forms an incrustation of an extent of about I5mni, and it is very thin, not reaching 0-5 mm. The colour (in spirit) is light brownish grey. The surface is somewhat hispid from projecting spicules. The dermal membrane is a thin, transparent film, resting on the skeleton below. Oscula and pores: larger and smaller, simple circular openings are seen in the dermal membrane representing I think both oscula and pores. The skeleton. The dermal skeleton consists of bundles of dermal spicules stretching up to the dermal membrane and supporting it, the spicules in the bundles being somewhat penicillately spread outwards; the bundles are generally not large, consisting only of relatively few spicules. There are PORIFERA. III. Ilg no horizontal spicules in the membrane itself. The main skeleton is constructed as usual of acantho- styli with their heads placed on the shell, the longest of them reach t<> the dermal membrane and project beyond it. At the base there is a small amount of spongin. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli which are divided into two groups, large and small; the large styli are generally slightly curved, they are a little thickened at the base, but there is no head-swelling, they taper only slightly outwards and the point is somev, hat short; the styli are spined in almost the whole length, only a small part of the apex being smooth or nearly smooth; at the base the spines are of medium size and numerous, outwards the}1 are small, nearly gritty, and more scattered. The small styli are mainly of the same shape as the large, they are straight or slightly curved and have likewise no head-swelling, but they are spined in the whole length. The length of the large styli is 0-29— 0-41 mm with a thickness at the base of cvoi6 — 0-021""", the small styli are 0-11—0-13""" long with a diameter at the base of o-on— 0-014 mm. 2- The dermal spicules are tylota with the swollen ends pointed like tornotes; the shaft is slender and generally straight, sometimes it is very slightly polytylote; the ends are distinctly but not much swollen, and they are pointed in such a way that the spicule might be termed a tornote were it not for the swellings. The length is 0-16— o-22mm, and the diameter of the shaft is 0-0028 — o-oo4nu". b. Microsclera are of two forms, ancorce spatuliferae and sigmata. 1. The aucorse resemble those in interjecta, but they are a little less curved or the curve is distinctly localized in the middle of the shaft; they have three elliptical teeth at each end, the alse are not large but distinct and always present. This ancora is thus evidently related to that in interjecta, but it is less chel-like. The length is 0-022— 0042 mr and the thickness of the shaft is 0-002— 0-004 mm; tne large aucorse are by far the most numerous while the smaller are seen only rarely. 2. The sigmata are of ordinary shape and they are contorted, generally a quarter of a turn. The length is 0-035— 0-045 mm an^ tne thickness about 0-0028""". The sigmata occur in the tissue of the sponge but not in the dermal membrane, the ancone occur also in the tissue but especially in the dermal membrane and here rather numerously. This and the preceding species are nearly related, but they are characteristically different 111 the shape of the dermal spicules, the size of the sigmata and also in the shape of the ancorae. Locality: South of Iceland, 630 21' Lat. N., 160 22' Long. W., depth 296 fathoms (The Fishery investigation steamer "Thor"). 3. H. duplicata n. sp. PI. XI, Fig. 6. Incrusting; surface hispid.' Spicula: megasclera; the skeletal spicules acanthostyli with a small but distinct head-swelling, the largest only spined at the base, the shorter they are the longer a part is spined, and the shortest are spined in the whole length, o-u—o-jj""". not divided into two groups; the dermal spicules tornota 0-238— 0-3 imm; microsclera ancorce spatulifera of two forms, la ith$—6 teeth, 0-062— o-o? /'""■■. small, with 8—11 teeth. 0-032 — 0-038""". This interesting species grows as thin incrustations on Brachiopod-shells; its greatest extent is umm and the thickness is about 0-25""". The colour (in spirit) is whitish or light yellowish. The mrface is in the present condition of the sponge strongl) hispid from projecting acanthostyli, but it I20 PORIFERA. III. is probably not so in the fresh state. The dermal membrane seems to be quite wanting in the speci- mens, so that I can say nothing .about it or about pores and oscula. The skeleton. The dermal skeleton; as the dermal membrane is quite or nearly quite wanting I can sav only little about the dermal skeleton; it seems to be of a construction like that found in the preceding species and thus consists of bundles of spicules stretching from the main skeleton to the dermal membrane. The main skeleton is quite of the common construction, the acanthostyli reach to the surface and they project as said beyond it. A small amount of spongin is visible at the sub- stratum around the heads of the acanthostyli. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli of a somewhat characteristic shape; they have a head-swelling which is not large, but generally distinct, they taper evenly into the apex, but the point is a little more abrupt. The largest styli have only spines below; the head is beset with somewhat robust spines, and there are very small spines on the part just above the head; the shorter the styli are the more spined they are and the smallest styli are spined near to the point. The spines on the head are blunt, giving the head in the large styli a characteristic appear- ance; the spines of the shaft are relatively largest in the small styli. The styli vary much in length, but they are not divided into two distinct groups. The length is 0'I2— 0-47 mm, and the diameter of the head 0-017 — °'°37 mm- The smallest styli are the most numerous. 2. The dermal spicules are slender and straight, or very slightly curved tornota, they are of the same thickness in the whole length; the ends generally form typical toruotal points, only sometimes the shape is less pronounced. The length is 0-238 — 0-31 mm and the diameter is 0-0028 — 0-004 mn\ D- Microsclera ; these are ancorae spatuliferse of two forms and sizes, large and small; they are both very beautiful spicules. 1. The large an corse have a very slightly curved shaft and five to six elliptical teeth at each end; there are somewhat narrow alae 011 the shaft, reaching a little longer towards the middle than the teeth. Sometimes the number of teeth at each end is not equal, but may be five at one and six at the other end; also some irregularity may be found, and when there are six teeth, generally one or two are a little smaller than the others. The length is 0-062 — 0-071 nim, and the diameter of the shaft is 0-004 — o-oo7mm. 2- The small ancorse have a shape somewhat similar to that of the large, but they have eight to eleven teeth at each end; the number of teeth may also here be different at the two ends; there are small alee on the shaft, but the}- are not directed to the sides but backwards, they are thus not or almost not seen when the ancora is viewed from in front, and they are on the whole difficult to see; from the fact that they are directed backwards they get a position similar to the falxes of the teeth, and teeth seem in reality sometimes to be formed here, so that there is a circlet of teeth all round; the construction recalling what is found in the ancorae of some of the Iotrochota species, e. g. /. rotulancora (The Danish Ingolf Exp. VI, 2, Porifera, Part. II, 191, PI. XVIII, fig. 6 c— e). The length is 0-032— 0-038 mm, and the thickness of the shaft 0-003 mm. Of this aucora some developmental stages were seen; they showed a dilatation with beginning teeth at each end, and they thus resemble the developmental stages of the ancora in the mentioned Iotrochota species. The microsclera occur in the tissue of the sponge, and to judge from a single place on one of the specimens they also occur in the dermal membrane in somewhat great numbers; the small ancorae are by far the most numerous. PORIFERA. HI. I2I This species is related to //. umbellifera Tops., but besides other characters this latter species has only one form of ancorse. Locality: Station 89, the Denmark Strait, 640 45' Lat. N., 27° 20' L,ong. W., depth 310 fathoms; two specimens. 4. H. tenuisclera n. sp. PI. XI, Fig. 7. Incrusting; surface smooth. Spicula: megasclera; the skeletal spicules acaiifhosfyli with a small but generally distinct head, somewhat densely spined in the whole length, 0-083 — (rigmm, not divided into two groups ; the dermal spicules strongyla o-i^ — u-ji"""; microsclera small isancorcB unguiferce with 5 — 8 tee Hi at each end, o-o/6 — O'ojo""". This species forms incrustations on Bryozoa [Retepora and Ccllcpora), on Brachiopods and on tubes of Placostegus frideu/afus. Its greatest extent is about 15""", and it is very thin, not reaching 0-5 mm. The colour (in spirit) is whitish. The surface is smooth or it may be finely hispid from pro- jecting acanthostyli, but this latter condition is certainly due to some damage. The dermal membrane is a thin and transparent film. Oscula and pores were not observed. The skeleton. The dermal skeleton consists of bundles of dermal spicules stretching from the skeleton below to the dermal membrane, the spicules are somewhat penicillately spread outwards; besides these bundles some more irregularly scattered spicules are seen; the bundles and spicules are not at all densely placed, and the dermal skeleton is somewhat weakly developed. The main skeleton is of typical construction, and it is rather regular, consisting of vertical acanthostyli. At the base there is a very small amount of spongin, only observable with difficulty. Spicula: a.. Megasclera. 1. The skeletal spicules are acanthostyli; they are generally straight, only rarely very slightly curved; the head is not large but as a rule distinct, and the shaft tapers evenly from the head to the point. The styli are somewhat densely spined in their whole length, sometimes the spines may be a little more dispersed towards the point; the spines are medium sized and reclined, on the head they are somewhat long, blunt and radiating straight out. The styli vary somewhat in length, but they are not divided into groups; the length is 0083— o-ig™"1 and the diameter of the head cron — 0-024 n,m- 2- The dermal spicules are straight and slender strongyla; they are of the same thickness in the whole length and sometimes they are a little polytylote; the ends may be slightly swollen. The length is 0-15 — 0'2imm and the diameter 0-0028— 0-004 mra. b. Microsclera; these are isancorae anguifera;; they are small and have a slender, curved shaft and five to eight narrow teeth at each end; there may be some irregularity present, the teeth sometimes being of different length and breadth and often the number of the teeth is different at the two ends; there are very narrow ala; on the shaft, but they are difficult to observe. The curvature of the shaft is generally very strong, but there is some variation on this point, especially in different individuals. The length of the ancorce, which is somewhat dependent on the curvature, is 0-016—0-020" "", and the diameter of the shaft is about o-oor""". The ancone are present in great numbers in the dermal membrane but occur also otherwise in the tissue. This species is very nearly related to //. biscutella Tops., but it is distinguished by several The [ngolf-Expedition. VI. 3. 16 j 22 POR1FERA. III. characters, the acanthostyli are smaller and the aucorse in biscutella are described as having ten or about ten teeth ("une dizaine"), and they are larger, 0-027— 0-030 mm; finally the present species does not show the "cellules spheruleuses" mentioned by Top sent for bisctitella. Locality: Station 6, 63° 43' Lat. N., 140 34' Long. W., depth 90 fathoms; station 32, 66° 35' Lat. N., Sf> 38' Long. W., depth 318 fathoms; further it has been taken at 63° 18' Lat. N., 21° 30' Long. W., depth 94 fathoms (The Fishery investigation steamer "Thor"); 6i° 40' Lat. N., y° 40' Long. W., depth 135 fathoms (Ditlevsen); 620 23' Lat. N., 2° 35' Long. E., depth 217 fathoms (Ad. Jensen, the cruise of "M. Sars" 1902). In all six specimens. The localities are situated in the Davis Strait, South and East of Iceland, West of the Faroe Islands and between the latter and Norway. Leptolabis Tops. Intrusting forms ; external appearance, skeleton and viegasclera as in Llymedesmia; the dermal spicules tylota ; the characteristic microsclcra are forcipes of one or two forms, to these are added chela' arcuata- and sigmafa. Topsent founded this genus in 1904 (Resultats des camp, scient. du Prince de Monaco, Fasc. XXV. 181) and I think he was right, the presence of forcipes being here, as in the genus For- cepia, of sufficient importance for the creating of a genus; moreover the dermal tylota seem to be characteristic for the genus. The genus Leptolabis comprises at present the following species: 1888. L. luciensis Tops. Arch, de Zool. exp. et gen. 2. VI, XXXVII, (Dendoryx). 1892. L. exilis Tops. ibid. 2, X, XXII, (Leptosia). 1904. L. forcipula Tops. Resultats des camp, scient. du Prince de Monaco, Fasc. XXV, 182, PI. XV, fig. 1 1. « L. forcipula var. brunnea Tops. ibid. 182, PI. XV, fig. 12. « Z. arcuata Tops. ibid. 183, PI. XV, fig. 18. 1905. L. irritans Thiele, Zool. Jahrbiicher, 1905, 455, Taf. 31, Fig. 71 a— e [HymcdesmiaX L. assimilis mihi. I have remarked below, that I consider L. forcipula var. brunnea as a definite and separate species; the same may I think be said with certainty about L. luciensis and exilis; on reading the description of luciensis of 1904 I got the impression that besides exilis perhaps still a third species may be hidden here. I. L. assimilis n. sp. PI. XI, Fig. 8. lncrushng ; surface smooth. The main skeleton weak. Spicula : viegasclera ; the skeletal spicules acanthostyli divided into two groups, large and small; the large without head, somewhat densely spined in almost the whole length. 0-42— 0-53""" ; the small with a slight head, spined in about the lower half, o-oSp — o-j/"""; the dermal spicules tylota with small swellings, 0-38—0-50""" ; viicrosclera four forms ; chela', arcuata; 0-014— 0-038""", sigmata o-ojj — o-/6""", spinulous forcipes of tzvo forms, large, with legs of equal length, 0-024—0-034""". small, with unequal legs. 0-014—0-018""". PORIFERA. III. "3 Tin's species grows on a large stone together with a Sarcophyton and various sponges of the genera Tcdania, Hymcdcsmia and Crclla. It forms an incrustation of a greatest extent of 30"", the thickness being scarcely 0-5""". The colour (in spirit) is greyish. The surface is smooth without | jecting spicules. The dermal membrane is not especially thin and it is somewhat solid; it is charged with microsclera, especially sigmata, and there are fibres of dermal spicules in it or just below it. Osciila and pores were not observed. The skeleton. The dermal skeleton consists of bundles and fibres stretching up to the dermal membrane, but in a very horizontal direction, and especially there are fibres running almost or quite horizontally in or just below the membrane; the dermal skeleton is thus chiefly constructed of hori- zontal fibres, and the fibres may reach some length; otherwise they have a more or less irregular course, and they are often curved; they may be of different thickness but are often rather thick, e. g. o-iomm. The main skeleton consists of acanthostyli placed with the heads on the substratum and directed vertically, or generally more or less obliquely upwards; they are much scattered and present only in somewhat small number; the main skeleton is thus diffuse and irregular and on the whole somewhat weakly developed. The acanthostyli are not evenly scattered over the surface of the sub- stratum, but they are to some degree collected in bundles with a few spicules in each. There seems to be a small amount of spongin at the base of the acanthostyli. Spicnla: a. Megasclera. 1. The skeletal spicules are acanthostyli which are divided into two groups, large and small; the large styli are straight or a little curved; the basal end is rounded, without any head-swelling or with this only very weakly developed, the other end tapers into a middle-long apex. The styli are somewhat densely spined in almost their whole length, only a short apical part being smooth; the spines are of medium size or small, and they are not reclined but radiating straight out; on the basal part there may sometimes be some stronger spines. The length of the large styli is 0-42— 0'53mm and the diameter at the base 0-017— 0-024 """• The small styli are straight; they have generally a somewhat distinct but small head, and the point is somewhat short; the spinulation is continued somewhat beyond the middle so that the apical part is smooth. The length is 0-089— °'21 mm a"d the diameter at the base o-oio— o-oi4mm. The small acanthostyli are oi rather scarce occurrence. 2. The dermal spicules are tylota; they are straight or sometimes slightly curved, the shaft is cylindrical, not thickened in the middle; the ends have small but somewhat distinct swellings; one end is a little thinner than the other and has the swelling more suddenly marked, but this feature is only slightly pronounced and only noticed by close examination. The length of the tylota is 0-38 0'50mm and the diameter of the shaft 0-0046— 0-007 mm. b. Microsclera are of four forms, chelae arcuata, sigmata and forcipes of two forms. 1. The cliche have an evenly curved shaft, the alse are lobe-shaped, somewhat narrow and deeply incised below, the tooth is elliptical, of the same length as the ake. The chela varies much in size, the length is OO] | and the diameter of the shaft o-ooi— 0-004'""'. The intermediate sizes are not numerous and hence the chelae give the impression of being divided into two groups. _'. The sigmata are large, oi common shape and more or less contorted; they vary somewhat in size, the length is 0-077 016 . ami the thickness is 0-0040— 0'Oo8m'". 3. The large forceps is of the ordinary hair-pin-like shape with legs of equal or about equal length; they have a round curve above, and the legs arc somewhat divergent; I2, PORIFERA. III. sometimes the legs are curved slightly outwards and then a little more divergent below; these for- cipes have thus a shape about as the large forcipes in Forccpia Topsentii (The Danish Ingolf Exp. VI, 2, 1905, PI. XIX, fig. 4 d). The forcipes are grittily or rugosely spinulous, and the legs are irregularly rounded or somewhat pointed at the apex, without any knob; they are smooth on the inside of the upper curve. The length of the forceps is 0-024— 0-034 mm, and the thickness of the rod is above in the curve 0-0035 — 0-0056 mm. In single cases the forceps has the legs extraordinarily divergent, so that the angle is obtuse; this feature is thus parallel to what is likewise the case with the forceps in Forccpia Topsentii. (1. c. fig. 4 e). 4. The small forceps has the legs parallel or slightly divergent, and one leg is longer than the other; this longer leg is curved slightly inwards; the legs terminate with a little knob. This forceps recalls thus the forceps in Forccpia Thielei and F. groenlandica (The Danish Ingolf Exp. VI, 2, PI. XIX, fig. 5d, PI. XX, fig. 3d.); it is inconspicuously spinulous. This forceps is very small, the total length from the curvature to the end of the long leg is 0-014— o-oi8mm, and the thickness above in the curve is about 0-0007 mm. Of the microsclera the chelae and sigmata are numerous, they are seen especially in the dermal membrane, but occur also through the whole sponge; the forcipes are not numerous but of somewhat rare occurrence, and they are not seen in the dermal membrane; otherwise it must be remarked, that the small forceps is difficult to detect on account of its very small size, and it is therefore very liable to be overlooked. This species is evidently nearly related to L. forcipula var. brunnca Tops, which I take to be certainly a distinct species, not specifically identical with forcipula ; but the present species differs from brunnca with regard to the size of both megasclera and microsclera; thus Topsent gives the size of the chela to 0-033 mm, an(^ ne does not speak of variation in size; the large forceps in brunnca has also a different shape, the legs being more divergent in their outer part; finally the acauthostyli in assimilis have no specially strong spines at the base and have not the spines on the shaft reclined, both these features being found in brunnca. I may also note, that in assimilis I have found no "cel- lules spheruleuses" which are mentioned by Topsent for brunnca. Topsent mentions, besides the larger forcipes, some small ones of a length of 0-013 mm and very thin, but he does not describe them more particularly; he thinks that they "representent soit la form jeune soit une etat athrophique de cette sort de mieroseleres". Developmental stages they cannot be, according to what we know about the development of the spicules, the growth taking place only by apposition; there is on the other hand also no reason to believe them to be atrophied forms. It is no doubt a special, small forceps, so that brunnca, like arcuata- and the present species, has also two forms of forcipes, large and small. • Locality: vStation 46, West of the Faroe Islands, 6i°32'Lat. N., n°36'Long.W., depth 730 fathoms. One specimen. Plate I. Plate I. Page Fig. i. Tedania suctoria O. Schmidt. The large papilla is an oscular papilla. I/I i — 2. Tedania suctoria O. Schmidt. A branched specimen, partly incrusting a Ptilota. 1jl — — 3. Tedania suctoria O. Schmidt. Incrusting specimen on an Allopora. I/1 — — 4. Tedania suctoria O. Schmidt. Pore-papilla in longitudinal Section, x about 30 — 5. Tedania suctoria O. Schmidt. Oscular papilla in longitudinal section, viewed from inwards, x about 30 — 6. Histoderma appendiculatum Cart. Most fistulse broken off, one ending in the way mentioned in the text Ijl 7 7. Histoderma appendiculatuni Cart. Small specimen. I/I — 8. Histoderma appendiculatuni Cart. Section showing the small incurrent canals radiating inwards from the space below the dermal layer, and some larger, excurrent canals. l ■', — 9. Histoderma appendiculatum Cart. The inner body, removed from the dermal layer, showing the openings of the incurrent canals, seen translucently as dark points. 2/,. — — 10. Histoderma appendiculatum Cart. A piece of the surface of the inner body at the base of a fistula, showing the fibres at the surface, running together towards the base of the fistula, x 32 — — 11. Histoderma appendiculatum Cart. End of a pore-fistula, x about 20 — — 12. Histoderma physa O.Schmidt, groviug on a stone; the specimen has two oscular tubes. t/I 11 — 13. Histoderma physa O. Schmidt. Oscular tube with pore-sieve on the side, x about 3.... — I / .7 l.i \ m ■ i /!■ Plate II. Plate II. Page Fig. I. Histodermella Ingolfi n. sp. The body somewhat contracted and broken below. l\x . . . . 14 — 2. Histodermella Ingolfi n. sp. Quite irregular specimen. I/I — — 3. Histodermella Ingolfi n. sp. Somewhat tubular specimen. 1/I — 4. Histodermella Ingolfi n. sp. Small specimen. J/i — — 5. Histodermella coriacea n. sp. A typical specimen; above an osculum, most of the other papillae are pore-papillae; below the sponge is broken; above there is a Verruca. '/, . 16 — 6. Histodermella coriacea n. sp. Tubular, branched specimen, broken below; the pointed papilla is an oscular papilla. I/I — 7. Inftatclla pellicula O. Schmidt. The base of attachment is seen; a tube is shown; rem- nants of the inner body shine through the dermal layer; the specimen is damaged above 2/x 18 8. Inftatclla pellicula O.Schmidt. Two tubes present; the dermal layer somewhat contracted and the peduncle broken; the inner body is distinctly seen shining through. 2/l — — 9. Inflatella pellicula O. Schmidt. The peduncle with stoles; a tube is seen; below the remaining part of the inner body shines through. 2/I — — 10. Inflatella viridis Tops. Somewhat club-shaped specimen; four oscular and one pore-papillae are seen; bottom material is seen adhering below; remnants of the inner body shine through. £/i 20 — n. Inflatella viridis Tops. A somewhat low specimen; five tubes are seen, all contracted; below some adhering bottom material l/\ — — 12. Inflatella viridis Tops. Pore-tube, showing the pore-membrane and the skeleton of the wall, x about 5 — — 13. Cornulum textile Cart. Somewhat damaged above. :/i 22 — 14. Cornuluui textile Cart, with a Bryozoon. l/t — — 15. Grayella pyrula Cart. A two-branched, compressed specimen; oscula are seen. 1/I 30 — 16. Grayella pyrula Cart. A two-branched specimen with two oscula. '/■ — — 17. Grayella pyrula Cart. Somewhat slender, club-shaped specimen with seven oscula. I/l. . — — 18. Grayella pyrula Cart. An unstalked specimen; several oscula are seen. I/I — — 19. Grayella pyrula Cart. Small specimen with one osculum at the summit. »/, — — 20. Grayella gelida n. sp. An osculum at the summit; the specimen shows wrinkles in the curve, caused by contraction. I/l 34 Tin- fiu/olf F..r]tc,lHion . !'/•>. in 13 14 /.■; /<> f it ia Plate III. Plate III. Page Fig. i. Hymedesmia rugosa n. sp. Two oscula are seen. 2/r 50 Hymedesmia stylata n. sp. Two oscular papillae are seen. l/1 57 Hymedesmia verrucosa n. sp. A fragment. ' ', 58 Hymedesmia perforata n. sp. r /i 61 Hymedesmia basispinosa n. sp. r/i 64 Hymedesmia occulta Bow., with distinct papillae. y, 67 Hymedesmia simillima n. sp. (a) on a stone together with a Hymeraphia (b); one oscular and two pore-papillse are seen. 1/1 69 8. Hymedesmia Bowerbanki n. sp. (tf) and //. clavigera n. sp. (3) growing together on a stone; below them is a Polymastia; c. is a Mesapos, and to the left of it grows a Bryozoon. I/1 . . 62, 75 — 9. Hymedesmia trun'cata n. sp. on a stone; six papillae are seen. I/I 77 — 10. Hymedesmia latniiicnlioides n. sp., in the middle the oscular papilla. I/1 78 ■ 11. Hymedesmia crux O. Schmidt and H. uummulus n. sp.; the large sponge is H. crux. oscula are distinctly seen; the circular, white spot is the base of a Horn era, on the left side of it grows H. uummulus ; a. is a Mesapos. r/i 55> §3 - 12. Hymedesmia tilifera O. Schmidt; peeled from its substratum. y, 86 — 13. Hymedesmia grandis n. sp. A large, somewhat folded specimen, seen from above; on two places the substratum of large sponge-spicules is seen. '/, 88 14. Hymedesmia grandis n. sp. A specimen cut through, showing the substratum of large sponge-spicules; the bordering line of the sponge-tissue downwards is distinctly seen. lj1 — Hymedesmia digitata n. sp. y, 90 — 15 — 16 — 17 — 18. — J9- — 20. — 21 Hymedesmia trichoma n. sp., growing on an Astarte-sheW. 1/1 91 Hymedesmia dermata 11. sp. Oscular cones are seen. I/I 107 Hymedesmia tornotata 11. sp., on a Brachiopod. I/1 109 Hymedesmia mucroiiclla n. sp., on a fragment of a Sip/10. r/i IID Grayella carnosa Tops. Cushion-shaped specimen, growing on a piece of Biemma rosea. t/I 36 Grave/la carnosa Tops. Erect specimen with two oscula at the summit; at the base some adhering bottom material. 2 , 36 Tin Ingolf- Expedition, VI. 3. 7 /*////. W' lk< i'i 10 •*«, i . 13 HI r< tit '" 10 18 •JO Plate IV. Plate IV. Page Fig. i. Tedania suctoria O. Schmidt, a styli of various sizes, b tylota x 200, c rhaphides of the three different sizes, all from one specimen x 380, d the upper end of one of the largest and one of the smallest rhaphides x 1400 1 — 2. Histoderma appendiculatum Cart, a tylota with intermediates to strongyla from the dermal layer and the inner body x 165, b cheke arcuatae , side and front view x 1000, c sigmata x 460 7 3. Histoderma physa O. Schmidt, a strongyla of various sizes x 165, b chelae arcuatoe, front and side view x 1000, c trichodragma x 380 11 ■ 4. Histodermella Ingolfi n. sp. a tylota of various sizes, b a young and an older develop- mental stage, c acanthoxea, d a not quite young developmental stage x 200, e chelae arcuatae side view, a little from behind, and front view x 1000, f sigmata x 460.... 14 5. Histodermella eoriacea n. sp. a strongyla of various sizes from the dermal layer and the inner body; with the magnification used the spinulation of the ends is not seen, b acantho- strongyla x 165, c ends of two strongyla, showing the minute spinulation x 700 ... 16 — 6. Inflatella pellicula O. Schmidt, a strongyla of various sizes, b a developmental stage x 200 18 — 7. Inflatella viridis Tops, a strongyla of various sizes, b a developmental stage x 165 20 Plate V. Plate V. Page Fig. i. Cornulum textile Cart, a strongyla x 200 b the two ends of a distinctly spined strongylum x 700, c chelae arcuatae, front and side view x 1400, d toxa x 340 22 2. Grayella pyrula Cart, a tornota, b acanthostyli x 255, c ehelse arcuata;, front and side view x 1000 30 ■ 3. Grayella gelida n. sp. a tornota, b acanthostrongyla x 255, c chelae arcuata; front and side view x 1000 34 ■ 4. Grayella carnosa Tops, a tornota, b acanthoxea, c a developmental stage x 255 36 ■ 5. Hymedesmia Koehleri Tops, a acanthostyli of various sizes, b polytylote strongyla x 255, c chelae arcuatae, front and side view x 1000. The spicules are from a typical specimen 42 ■ 6. Hymedesmia lacera n. sp. a acanthostyli of various sizes, b strongylum x 255, c chela arcuata, side view x 1000 44 7. Hymedesmia storea n. sp. a acanthostyli of various sizes, /; strongylum x 255, c chela arcuata, side view x 1000 45 8. Hymedesmia lamina n. sp. a acanthostyli of various sizes, b strougylum x 255, c chelae areuatse, side and back view x 1000 46 The hiyoir /:'.i/n tlifioii . I 7 V s Plate VI, Plate VI. Page Fig. i. Hymedesmia mollis n. sp. a acanthostyli of various sizes, b strongylum x 255, c chelae arcuatae, side view x 1000 47 2. Hymedesmia curvicliela n. sp. a acanthostyli of various sizes, b strongylum x 165, c chela arcuata, side view x 1000 48 3. Hymedesmia rugosa n. sp. a acanthostyli, large and small, b strongylum x 255, c chelae arcuatae, front and side view x 700 50 • 4. Hymedesmia splenium n. sp. a acanthostyli, large and small, b strongylum x 255, c chela arcuata, side view x 1000 51 5. Hymedesmia tenuicula u. sp. a acanthostyli, large and small, b strongyla x 255, c chela arcuata, side view x 1000 52 • 6. Hymedesmia similis n. sp. a acanthostyli, large and small, b strongylum x 255, c chela arcuata, side view x 1000 53 — 7. Hymedesmia immmulits n. sp. a acanthostyli, large and small, b strongylum x 165, c chela arcuata, side view x 1000 55 8. Hymedesmia di/bia n. sp. a acanthostyli, large and small, b strongylum x 255, c chela arcuata, side view, a little from the front so that the flat front side of the shaft is seen x 1000 56 — 9. Hymedesmia stylata n. sp. a acanthostyli, large and small, b strongylum x 255, c chela arcuata, side view, a little from the front x 1000; when seen accurately in side view, the alae would be more claw-shaped 57 Tin Iin/till F.rji, ililiou s ■ Plate VII. Plate VII. Page Fig. i. Hymedesmia verrucosa n. sp. a acanthostyli of various sizes, b strongylum x 255, c chelae arcuatae, oblique front view and side view x 1000 58 — 2. Hymedesmia procumbens n. sp. a acanthostyli of various sizes, b tornotum x 255, c chela arcuata, side view x 1000 60 — 3. Hymedesmia perforata n. sp. a acanthostyli of various sizes, b tornotum x 255, c chelae arcuata; of various sizes, side view x 1000 61 4. Hymedesmia clavigera n. sp. a acanthostyli, large and small, b tornotum x 255, c chela arcuata, side view x 1000 62 5. Hymedesmia platychela n. sp. a acanthostyli of various sizes, b tornotum x 255, c chela arcuata, front view x 1000; one tooth is cleft 63 6. Hymedesmia basispiuosa n.sp. a acanthostyli, large and small, b tornotum x 255, c chela arcuata, side view x 1000 64 — 7. Hymedesmia longistylus n. sp. a acanthostyli of various sizes, b tornotum x 165, c chela arcuata, side view x 1000 66 — 8. Hymedesmia occulta Bow. a acanthostyli, large and small, b one of the tornota, c one of the oxea from the dermal skeleton, d one of the thicker oxea from the dermal mem- brane, c one of the specially thick dermal oxea from the specimen mentioned in the text x 165, / chelae arcuatae, side and front view x 1000 67 ■ 9. Hymedesmia simillima n. sp. a acanthostyli, large and small, b dermal oxeum, c one of the thick dermal oxea x 165, d chela arcuata, side view x 1000 69 I "I - Plate VIII, Plate VIII. Page Fig. i. Hymedesmia baculifera Tops, a acanthostyli of various sizes (from a specimen with large styli), b tylotum x 255, c chela arcuata, side view x 1000 71 — 2. Hymedesmia levis 11. sp. a acanthostyli of various sizes, b polytylote tylotum x 255, c chela arcuata, side view x 1000 73 — 3. Hymedesmia bractea n. sp. a acanthostyli, large and small, b tylotum x 255, c chela arcuata, side view, a little from in front x 1000 74 — 4. Hymedesmia Imvistylus n. sp. a acanthostylus, b tylotum x 255, c chela arcuata, side view, a little from in front x 1000 74 — 5. Hymedesmia Bowerbanki n. sp. a acanthostyli, b tylotum x 340, c chela arcuata, side view x 1000 75 — 6. Hymedesmia truncata n. sp. a acanthostyli, b tylotum x 340, c chela arcuata, side view x 1000 77 — 7. Hymedesmia latrunculioides n. sp. a acanthostyli, b tylotum x 340, c chela arcuata, side view, a little from in front x 1000 78 8. Hymedesmia irregularis n. sp. a acanthostyli of various sizes, b polytylote dermal stylus x 255, c chelae arcuatae, front and side view x 1000 80 — 9. Hymedesmia proxima n. sp. a acanthostyli, large and small, b dermal stylus x 255, c chelae arcuatae, front and side view x 1000 81 - 10. Hymedesmia crux 0. Schmidt, a acanthostyli of various sizes, b subtornotum x 255, c chelae arcuatae, front view (the spines on the back of the shaft are seen shining through) and side view, d seen from the end x 1000 83 Illf/oll I'.riiiililniii 17 .'/. v / Plate IX. Plate IX. Page Fig. i. Hymedesmia aenigma n. sp. a acanthostyli of various sizes, b tornotum x 255, c—f asteroid chela; in various views, c the axis distinct, with the convex side to the right, d the axis cannot be pointed out, e front view, the axis in the middle, f seen from the end, g a developmental stage x 1000 84 2. Hymedesmia Jilifera O.Schmidt, a acanthostyli of various sizes, b strongylum x 255, c chela arcuata, side view x 1000 86 — 3. Hymedesmia grandis n. sp. a acanthostyli, large and small, b strongylum x 255, c chelae arcuatae, front and side view x 1000, d sigmata of various sizes x 460 88 ■ 4. Hymedesmia digitata n. sp. a acanthostyli, large and small, b tylotum x 255, c chela arcuata, side view x 1000, d sigmata x 460 90 5. Hymedesmia trichoma n. sp. a acanthostyli, large and small, b tylotum x 255, c chela arcuata, side view x 1000, d sigmata x 460 91 - 6. Hymedesmia macrosigma n. sp. a acanthostyli of various sizes, b strongylum x 255, c chelae arcuatae of various sizes, side view x 1000, d sigmata, large and small x 340 92 7. Hymedesmia pugio n. sp. a acanthostyli, large and small, b dermal stylus x 255, c chela arcuata, side view x 1000, d sigmata x 585 94 - 8. Hymedesmia consanguinea n. sp. a acanthostyli, large and small, /> tornotum x 255, c chela arcuata, side view x 1000, d sigmata x 585 95 Plate X. Plate X. Page Fig. i. Hymedesmia planca n. sp. a acanthostyli, large and small, b tylotornotum x 255, c chelae areuatse of various sizes, front and side view x 1000, d large sigmata, e small, circularly curved sigmata x 585 96 2. Hymedesmia cultrisigma n. sp. a acanthostyli, large and small, b tylotum x 255, c chela arcuata, side view x 1000, d sigmata of the large, peculiar form, e sigmata of the ordinary form x 585 97 3. Hymedesmia mucronata Tops, a acanthostyli of various sizes, /; oxytornota x 255, c chela arcuata, side view, d — e the peculiar chela, d side view, e seen in oblique front view and somewhat from the end, in this view the points of the processes are not seen and the processes appear therefore rounded at the ends x 1000, f sigmata x 585 ... 98 ■ 4. Hymedesmia tenuisigma n. sp. a acanthostyli, large and small, b polytylote strongylum X 255, c sigmata x 460 100 5. Hymedesmia Dujardhiii Bow. a acanthostyli of various sizes, the middle one with a slight head-swelling 011 account of the shaft being thick below, b strongylum and tylotum x 255 101 — 6. Hymedesmia primitiva n. sp. a acanthostyli of various sizes, b polytylote strongylum x 255 104 7. Hymedesmia loigurius n. sp. a acanthostyli of various sizes, b a thinner and a thicker strongylum x 255 105 8. Hymedesmia a-quata n. sp. a acanthostyli of various sizes, b strongylum x 255 106 Plate XI. Plate XL Page Fig. i. Hymedesmia dermata n. sp. a acanthostyli, large and small, b strongylum x 255 107 2. Hymedesmia tornotata 11. sp. a acanthostyli of various sizes, b tornota with microspined ends x 255 109 3. Hymedesmia mucronella n. sp. a acanthostyli, large and small, b tornotum, the upper end with a mucro x 255 no — 4. Hymenancora interjecta n. sp. a acanthostyli, large and small, b tylotum x 255, c ancorae, front and side view x 1000, d sigmata x 460 117 5. Hymenancora conjungens n. sp. a acanthostyli, large and small, b tylotum with somewhat swollen ends x 255, c ancorae, side view and oblique front view, x 1000, d sigmata x 460 118 6. Hymenancora duplicata n. sp. a acanthostyli of various sizes, b tornotum x 255, c ancorae spatuliferae of the large form, oblique front view and side view, d ancorae spatuliferae of the small form, front view and side view, the latter shows two smaller teeth at the upper end x 1000 119 — 7. Hymenancora tenuisclera n. sp. a acanthostyli of various sizes, b strongylum x 255, c ancorae unguiferae, side view, with more and less curved shaft x 1000 121 ■ 8. Leptolabis assimilis n. sp. a acanthostyli, large and small, b tylotum x 255, c chelae arcuata.' of various sizes, side view x 1000, d large forcipes x 1000, e small forcipes x 1400, f sigmata x 340 122 17..'/. INGOLF-EXPEDITIONEN [895 — 189 6. STATIONERNES PLADS, DYBDE 00 BUNDTEMPERATUR. Dybde Bund- Dybde Bund- . de Buud- X. Brd. V. Lgd. idanske tempe- Stat,°" N. Brd. V. Lgd. idanske tempe- Statiol] N. Brd. V. Lgd. i danske tempe- ratur ' Fvn. ratur Fvn. ratur Xr. Fvn . r 62° 30 8° 21' 1 52 7°2 24 65° 06 56 00' 1199 2°4 45 2 63 04 90 22' 262 5°3 25 63 JO 5 1 25' 5S2 46 5 63° 35' 10° 24' 272 o°5 63 5i' 53 03 136 47 4 640 07' 11° 12' 237 2°5 26 63 57' 52 M' 54 4^ 5 64°4o' 12° 09' '55 64° 57' 51 24' 109 49 6 &3° 43' 14° 34' 90 7°o 27 64" 54' 55' lo- 393 vs 50 7 63° 13' 15° 41' 600 4°5 28 65° U ss \2 420 3°5 » 64 s 63c 56 24 40' 136 6°o 29 34' 68 0°2 52 65° 57' 9 64° IS' 27° 00' 295 5°S 3° 66 50' 54 -'S 22 i°o5 53 IO 640 24' 28° 50' 7SS 3°5 31 66 35' 55 54' ss 1 6 54 63 oS' >5C4<>' 1 1 640 34' 31° 12' [300 i°6 32 66" 55' ;i8 55 15-02' 12 64° 38' 32° 37' 1040 o°3 33 67° 57' 55° 3°' 55 0 s 56 64° 00' !3 64° 47' 34° 33' 622 3°o 54 65° >;■ 54' '7' 55 57 '4 64° 45' 35° 05' 176 4°4 35 1 6' 55 °5 ss 15 66° IS" 25° 59' 33° -o°75 56 61° 50 56 21' ■455 t°5 59 65 00' 16 65° 43' 26° 58' 250 6°i 57 60 17' 5 1 ' '5 >7i5 1 1 60 17 62° 49' 26° 55' 745 3°4 38 59 1 2 51 ' 05' [871 1 61 [8 61° 44' 30° 29' ' 1 35 3°o 3, 62 00' 22' 38' 2°9 62 '9 6oc 29' 34° 'I ,566 2°4 40 62" 1 ii .' ■ S45 ,0 , 20 58 IO' 40° 48' 1695 1 5 4, 61° 39' 1245 ->Lo 64 21 58° Ol' II \5' 1 53' ' 2°4 I-' 61 |T 10 1 7 22 58° IO' 48° 25' 1845 1 1 43 61 |j ' 61 ' 33' 2.5 60° 43' 56° 00' Eun IITl't-'l *KViK< II 6i° 42' - 645 .0, - 4 1 , 72" -. 0-> " 3° 1 7 1 1 20 2°9I .0, . 0 'o 420 705 (391 3°9 316 5°9 hs 35° 21 1 310 — o°i 124 55 0 »■» Station N. Hrd. V. Lgd. Dybde i danske Fvn. Bund- tempe- ra tur Station Nr. N. Brd. V. Lgd. Dybde i danske Fvn. Buiul- tempe- ratur Station Nr. N. Brd. V. Lgd. Dybde i danske Fvn. Bund- tempe- ratur 620 06' 22° 30' 843 3 t 92 64° 44' 32° 52' 976 i°4 11S 6S° 27 8° 20' 1060 — i°o 69 620 40' 2 2 c 17 5«9 3°9 93 64° 24' 35° 14' 767 !°46 119 67° 53' 10° 19' IOIO — i°o 70 22° 05' [34 7°o 94 64° 56' 36° 19' 204 4°r 120 67° 29' 11° 32' 8S5 — IcO 7" 22° 03 46 65° 3i' 30° 45' 213 121 66° 59' 13° ii' 529 — o°7 72 630 12' 197 6°7 95 65° 14' 3°° 39 752 2°I 122 66° 42' 14° 44' "5 i°8 73 620 5S' 23 >8' (S(, 5°5 96 65° 24' 29° 00' 735 I°2 123 66° 52' r5° 40' 145 2°o 74 620 17' 24c 36' "95 4°2 97 650 28' 27° 39 45o 5°5 124 67° 40' 15° 4o' 495 — o°6 61° 57' 25° 35' 761 98 65° 38' 26° 27' 13S 5°9 125 6S° oS' 16° 02' 729 — o°8 6i°2S' 25° 06' 829 99 66° 13' 25° 53' 1S7 6° 1 126 67° 19 15° 52' 293 -o°5 75 61° 28' 26° 25' 780 4°3 100 66° 23' 14° 02' 59 o°4 127 66° 33' 20° 05' 44 5°6 76 60 , 26° 50' 806 4° 1 101 66° 23' 12° 05' 537 -o°7 128 66° 50' 20° 02' 194 o°6 77 6o° 10' 26° 59' 95' 3°6 102 66° 23' IO° 26' 75o — o°9 129 66° 35' 23° 47' "7 6°5 78 60° 37' 27° 52' 799 4°5 103 66° 23' 8° 52' 579 — o°6 13° 63° 00' 20° 40' 33S 6°55 79 6o° 52' 28= 58' 653 4°4 104 66° 23' 7°25' 957 — I°l 131 63° 00' I90 09' 69S 4°7 So 61° 02' 29° 32' 935 4°o 105 65° 34' 7° 31' 762 — o°S 132 63° 00' 17° 04' 747 4°6 61° 44' 27° 00' 485 6°i 106 65° 34' S° 54' 447 — o°6 133 63° 14' 11° 24' 230 2°2 82 6i=55' 27° 28' 824 4°i 65° 29' 8° 40' 466 134 62° 34' IO° 26' 299 4°I 83 620 25' 28° 30' 912 3°5 107 65° 33' 10° 28' 492 -o°3 135 62° 4S' 9° 48' 270 o°4 620 36' 26° 01' 472 10S 65° 30' 12° 00' 97 I°i 136 63° 01' 9° 11' 256 4°S 620 36' 25° 3°' 401 109 65° 29' I3C 25' 38 i°S 137 63° >4 S°3i' 297 — o°6 s4 620 58' 25° 24' 633 4°S no 66° 44' "°33' 781 — o°S 138 63° 26' 7°56' 47i — o°6 8* 63° 21' 25° 21' 170 tit 67° '4' 8° 48' 860 — o°9 r39 63° 36' 7° 30' 702 — o°6 . — abyssicola M. Sars 79. gelida n. sp 83. tenuisigma n. sp 87. iniquidentata u. sp 91. corticocaucellata Cart 93. oxeata n. sp 97. Chondrocladia i".'. gigantea Ann. Hans. , ... [02. Artemisina tio. arcigera O. Schmidt 1 1 1 >. apollinis Ridlev and Dendy . .. 114. Homceodictya 117. flabelliformis Arm. Hans. 1 is. palmata Johnst. 1 -' r. Myxilleae Dendoricella rhophalum u. sp. obesichela n. sp. Myxilla — incrustans Johnst. rosacea Lieberk. fimbriata Bow. brunnea Arm. Hans, perspinosa n. sp. pedunculata n. sp. diversiancorata n. sp. pluridentata n. sp Lissodendoryx lobosa n. sp. Sophia Frstdt. fragilis Frstdt diversichela 11. sp. indistincta Frstdt. complicata Arm. Hans. vicina n. sp. stipitata 11. sp. Iophon Page 25- 26. 32- 41. 44. 47- 5°- 51- 53- 54- 53. 60. 62. 66. 69. piceus Vosm. . 1 75 dubius Arm. Hans. frigidus n. sp. (83. Iotrochota ' s? varidens n. sp. is^ oxeata n. sp. abyssi Cart. dubia a. sp. intermedia u. sp. 190. rotulancora n. sp. polydentata n. -.j) 192. affinis 11. s]). . 1Q4- spinosa u. sp. 195. Forcepia forcipis Bow. fabricans t ). Schmidt '1'. .ps< ntii ti, sp. . Thielei n. sp. . nlandica Frstdt. Melonam hora C irl elli] 211. emphj senia 1 ' Schmi.lt Porifera. II. By William Lundbeck. THE present work, as shown by the title, is a direct continuation of my work, Porifera, Part I, The Danish Ingolf-Expedition, VI, r, published in 1902. In the introduction to this first part I rendered an account of the material and of the geographical territory treated in the work. Since that time some new material from the territory has been added, and this material has been included in the work. The new material has especially been gathered by the surveying vessels the Diana and Beskytteren stationed at Iceland and the Faroe Islands, on the cruise of the Thor , the steamei of the international investigation of the sea, in 1903 under the direction of Dr. Job. Schmidt, and more particularly must be mentioned the very considerable material collected by Dr. A. Appellor and cand. mag. Ad. Jensen during the cruise of the Michael Sars in 1902 under the direction of Dr. Hjort. In the first part of the work the families Homorrhaphidce and Heterorrhaphida of the sub-order HalichondrincB were treated. The present part comprises part of the family Desmacidonidoe. Partly following Topsent I divide this family into the subfamilies Mycalina 1= Esperellina olim) and Ecty- onince; Mycalinm I divide into two groups Mycalem and Myxillea (the latter corresponding to the subfamily Dendoricinm of Topsent). I regard these two divisions as groups of one subfamily, as 1 think them more closely allied to each other than to Ectyonina, at all events when the question is of the typical forms of this sub-family. On the other hand, several genera of Ectyonina are assuredh closely allied to genera of the group Myxilleee. The systematism of the sponges is still in main respects groping its way, and such is also the fact inside the family Dcsmacidonida. The separation into the two subfamilies Mycalince ami Ectyonince is scarcely a quite natural one, in the way in which it is made at present, being chiefly based on the occurrence "I special, socalled accessory spicules in the latter subfamily. Thus the dermal spicules with equal ends characteristic of the . l/i \ .//.-.. . occui also in some Ectyonintz-genera.; the accessor) acanthostyles are often very scarce, "i the acanthostyles of the species are so very varying in size, that it is difficult to decide whether two separate groups of si/.es are present The decision is especiall) difficult in iucrusting forms, where the charade- of the accessory styles jutting nut from the fibres is wanting, all the styles being basal. A particulai fact is also the occurrence of parallel, corresponding genera in the two subfamilies; thus Myxilla (— The [ngolf-Expedition. VI. j. I PORIFERA. II. /),;. lint) corresponds to the Ectyonm-genvis formerly known by the name of Myxilla, Iopho?i to Pocillon. lotrochota to Hymetrochota , Grayella (— Yvesia Tops.) to Pytheas, and Tedania to Achcli- derma; also these facts seem to tell against the naturalness of the system. It; is therefore rather prob- able that the division into Mycalina and Ectyonhice will have to be abandoned or altered, as has already been advanced by Ridley and Dendy (Challeng. Report, Monaxonidse, 129), at the same time as they reduce Carter's family Ectyonida to a subfamily, and as will also be mentioned in several places of the present work. I have, however, not yet ventured to abandon this division, as my investigations have not hitherto shown me a more natural way of grouping. For the present the efforts must be directed towards a thorough examination of genera and species, as this will to a high degree facilitate the natural grouping with regard to the higher divisions. In the introduction to the first part I have spoken of several descriptive terms and their use, to which I may here refer. The terminology of the spicules is the same with regard to megasclera and to the forms of microsclera occurring in Heterorrhaphidcr. In the family DesmacidonidcB, however, we meet new forms of microsclera belonging to the socalled chelate type, and it will be necessary to premise some remarks on the two principal forms of this type Chelae and Ancorae. The spicules belonging to these forms are at this moment by all authors with the exception of Levinsen comprised under the name of chelae. This name was proposed in 1887 by Ridley and Dendy in Challeng. Rep., and this proposal was of some importance, as up to that time there had been no established term, but terms as auchorates , Haken , Anker a. s. o. had been used by the different authors. While Schmidt and Carter upon the whole have given good figures of these bodies, Bowerbank on the other hand was highly misled with regard to their forms; even Carter has in 1871 (Ann. Mag. Nat. Hist. 4th ser. VII, 277) pointed out this fact, but Levinsen and after him Ridley and Dendy have rendered a more particular account of it. Levinsen especially was he, who first and clearly showed (Dijmphna-Togtets zool.-bot. Udbytte, 1887, 354) that Bowerbank gener- ally figures the cheke in two positions, from before and from the side, and interprets these figures as two different forms. Another common mistake, that the tooth of the chela has not been seen, may be found in many works down to the present time; when this is the case the chela is figured with a plate in each. end, but without a tooth; or only the tuberculum has been seen and interpreted as forming a small short tooth. This mistake is easily accounted for, as the tooth is often so thin, that it can only be seen under high magnifying powers and by proper light. In this respect Ridley and Dendy 's Monaxonidae (Challeng. Rep.| occupies a high position by its excellent figures of the chelae. Otherwise the mistake is a common one; thus in the works by Vosmaer on the sponges of the Willem Barent -Kxpeditiou it is found throughout, and this holds also quite good of his work on the sponges in Bronn's Klassen und Ordnungen, where almost all the figures of chelae are erroneous, no corresponding forms being found in nature. In a paper by Vosmaer and Pekelharing from 189s (Verhandl. der Kon. Akad. van Wetensch. to Amsterdam, 2, IV, no. 3, 32) entitled On Anisochelae PORIFERA. II. and Isochel3e», and in which therefore a thorough examination of these features might be expected, we find nevertheless that on PI. II, fi.^. 9, and especially fig. 11, which latter represents an almost grown (rather a quite grown) chela, no tooth has been drawn in the smaller end. Also in Topsent's other- wise excellent works too little attention has been paid to the study of the chelae; in his work from 1892 (Resultats des Campagn. scient. du Prince de Monaco, Fasc. II) the chelse are shown in very small figures, and most frequently the tooth has not been figured. In the work on the sponges of the P.elgic Antarctic Expedition from 1902 (Voyage du S. Y. Belgica, Spongiaires) the rase is somewhat similar; thus the tooth is not drawn on the chela seen from the front, PI. Ill, fig. 9 b. Even in the fine work from 1904 (Resultats des Campagn. scieut. du Prince de Monaco, Fasc. XXV) errors of this kind are found; thus the chelae on PI. XIV, fig. 15 e, fig. 18 d, and PL XV, fig. 20, are drawn without the tooth, while others, especially the larger ones, are drawn correctly. As mentioned above, all these forms are generally comprised under the name of chelae, and are regarded as being principally of the same kind. In contradistinction to this view Levinsen in 1893 (Yidensk. Medd. fra den Xat. For. Knbenhavn 1893, x) nas advanced a new view, dividing tlu-si bodies into two principally differeut forms and giving to these the respective names of chela and ancorae. The difference between these two forms is briefly, that chelae have only one free tooth and besides more or less broad lateral aire on the shaft, while ancone have more, 3 — 7 free, uniform teeth besides lateral ake on the shaft, kevinseu regards the teeth in both forms as bendings of the axis. Carter and Ridley and Dendy regard the lateral teeth in ancone and the ake in chelae as formations of the same kind, and are most inclined to regard the lateral teeth in ancone as developed 1>\ the ake of a chela being split of from the shaft. Vosmaer and Pekelharing in the above quoted paper from 1898 attack the interpretation of Levinsen, and declare that the teeth of the ancorae cannot be interpreted as bendings of the axis, as long as an axial canal has not been made out in all the teeth "I the ancoras, and if these teeth are formed by the axis being bent and split in several branches, then a sponge with such spicules would not belong to the Monaxonidae. The authors think it most probable that the ancorae have arisen by a splitting of the tooth of the chela. To these different theories it is only to be remarked that it may be regarded as a fact that chelse and ancorae are allied bodies, but that it cannot at present lie decided, in what wa\ oik- form may be thought to have arisen from the other. Now it is certain that in a few chelae we may un with a feature which is probably a splitting of the tooth, as in some Asdesfopluma-species in the smaller end of the chela, and in the present work in the genus Myxilla instances will be shown oi ancorae with at all events a beginning splitting of teeth; but at present it is impossible to decide how this fact is to be interpreted. On the other hand it is certain that the two forms, as they now occur, are principally different: in one form, chelse, only one tooth is found and ake on the shaft, in the othei form, ancorae, several quite homologous teeth are always found as well as ake on the shaft. Transitional forms have not been found hitherto, and when Ridley and Dendy saj (Challeng, R Monaxonida, XIX): Numberless gradations exist between these two types , this is not correct; theii view arises from the fact, that they put ancone and chelae arcuatae together in one group in contra- distinction to chelae palmatae, but even from this point of view the statement is not correct. Tin objection of Vosmaer and Pekelharing, that the ancorae, if the representation of Levinsen is PORIFERA. II. correct, would be polyaxial spicules, seems to me to be of no importance, as the question might very well be of a secondary splitting of the axis of the original monactinal spicule. Otherwise I shall remark that it may be proved that the tooth of the chela can be traced back to a bent axial part, while the teeth of the ancorae, in spite of the fact that their form quite corresponds to that of the tooth of the chela, are, perhaps, not axial bendings, but are formations which have, all of them, also the middle tooth, arisen in another way, through growth by apposition. I cannot, however, at present establish this as a sure fact. If it should prove correct, Levinsen of course is not right in designating the teeth of ancorae as axial bendings, but the principal difference between chelae and ancorae will then be still greater. In this connection it may be well to remind of the fact that ancorae may be found provided with an even number of teeth, without any middle tooth. Besides the division into chelae and ancorae Levinsen, in the paper quoted, subdivides chelae into two forms, chelae palmatae and arcuatae. The former have a straight, or most frequently only slightly curved shaft, and rather large alae forming together an almost triangular or oval plate, often with a deep notch below; the tooth is often rather broad. In the other form, chelae arcuatae, the shaft is most frequently rather strongly curved, the alae are highly indented below and only attached to the shaft for a comparatively short way, thereby getting a somewhat tooth-like appearance; the tooth is most frequently rather narrow. To be sure, these two forms are not principally different, but differ only in form, and forms may also be met with that may only with difficulty be referred to either of them; but generally they form two well-marked groups, and are also characteristic for certain genera. Therefore there is every reason to keep this division. By all the authors who acknowledge only one form, chelae, these are generally described as tridentate or palmate . This division is a complete mistake; the forms called palmate are gener- ally chelae palmatae, but in the term tridentate are comprised both chelae arcuatae and ancorae. Thus Ridley and Dendy and Topsent use generally these terms; nay, in Topsent's work on the sponges of the Belgic Antarctic expedition we even meet again the old term bidente». Under Des- macidon setifer it is said in the text of the chelae dentes ou palmes , and on PI. Ill, fig. 6 a series is figured of which it is said in the explanation of the figures, «a, b, formes rudimentaires > ; this is cor- rect, the figures show two developmental forms; then the continuation runs, c, isochele palme, d, iso- chele dente, c', d', formes intermediates ■>. All the figures belong to one form, a typical palmate chela, c is seen from the front, d from the side, while c' and d' are two a little contort specimens, and one end is therefore seen a little from the front, the other a little from the side. Besides the division made by Levinsen of the forms belonging here, I further divide ancorae into two classes which I call ancorae spatuliferae and unguiferae. In the first form the shaft is most frequently straight or slightly curved, and the teeth are comparatively large and broad; their number is very frequently three, but there may be more. In ancorae unguiferae the shaft is most frequently more curved, the teeth are comparatively small and pointed, their number is three to nine, generally more than three. These two forms of ancorae are only different in form, and transitional forms occur, but the two forms are most frequently well-marked and characteristic of particular genera. In the palmate chelae the ends may be either like or unlike each other, and according to this they are either isochelae or auisochelae; in the arcuate chelae, the ends, as far as known, are always PORIFERA. II. like, and accordingly they are isochelae. In ancorae spatuliferae the ends, as far as known, are always like, they are isancorae, while ancorae unguiferse may be isancorae 01 anisancorae. According to the preceding the chelate microsclera may be divided into the following tonus: Chelae Ancorae palmatae arcuatae spatuliferae unguiferae most frequenth 3 9 teeth 3 teeth I iso- aniso- iso- iso- iso- amso- All forms of microscleres belonging here may always be referred to one of the- types chelae or ancorae. This does not seem to be generally acknowledged. Thus the small chela.- characteristic of the genus Asbestopluma have given rise to different interpretations, but in reality they are constructed on the same principle as the other chelae. Even so deviating a form as the chela in Mycale thautna- tochela described below is of the same fundamental structure, and this holds good also with regard to the peculiar wry chela in M. titubans; nay, even the bipocilla in the genera Iophon and Pocillon may be referred to the same form. Topsent (1 c. fasc. XXV, 209) proposes the term placocheles for the peculiar palmate isochelae in Guitarra and Esperiopsis villosa\ I cannot, however, see any reason for a special name for these forms, as thev are tvpieal isochelae palmatae. A typical chela thus con- sists of the following parts, which I designate by the following terms, generally in use: a shaft or an axis having in either end a bending, the tooth, and at either end two lateral extensions, the alae; between the shaft and the tooth, at a right angle to these, is found a plate-shaped part, falx, and the thickened j^art of this structure shining through the fore side of the tooth, is called tuberculum. In ancorae quite the same parts are found, the only difference being that in these several teeth are found each with falx and tuberculum. With regard to the development of these forms many misconceptions have been advanced. As early as in 1857 Bowerbank (Phil. Trans. Roy. Soc. London CXLVIII, 304) and later in the firsl volume of Monograph 1864, 47, PI. VI, fig. 144— 147, has given a description with figures of these forms, which, to be sure, is not correct, but nevertheless rather good and free of the misconceptions arising later, as he has clearly understood that the first beginning was of the same length as the fully developed spicule. Also O. Schmidt in 1862 (Die Spong. des adriat. Meer., 8), although he does not understand the growth of these spicules, has seen that small and large chelae occurring in the same sponge are not stages of growth of the same form. I.atei the misconceptions appear, Carl in 1874 (Ann. Mag. Nat. Hist. 4, XIV, too), advances the view that the anisochelae begin as isochi he has been led to this view by the fact that he upon the whole regards small isochelae, in a species also provided with large chelae, as younger stages of these, and so he is led to suppose .1 growth with the most peculiar alterations of form. That Carter has not latei been quite sure of the correct- ness of his theory may be seen from the fact that in iN.s_> (Ann. Mag. Nat Hist. 5, IX, 298) where he PORIFERA. It. mentions small isocheles occurring together with large anisocheles, he says: and therefore the inequi- anchorate ma\ possibly begin its development in this form (i. e. as isochela), and he continues, how- ever it does not occur in the ovular embryo of Esperia, while the inequiauchorate do. Ridley and Dendv, in Challeng. Monaxonida, follow Carter completely, though they have followed the develop- ment of anisoehelae in E. mammiformis. They still regard the small chelae as developmental forms of the large ones in the same sponge, either the question is of isochelae or anisochelse; in several places however, they say possibly young forms . Levin sen, in his paper from 1893, gives an exhaustive description of the growth of the chelae. In the introduction to part I of the present work I expressed the opinion that in this second part I should be able to corroborate his examinations with regard to a great number of forms, and this is also the case. In the descriptions of the separate species this tact will be more particularly mentioned. Here, as in the other spicules, the growth takes place exclusively by apposition, either simple apposition, or after fixed lines, and the younger forms must always be iuscribable in the older ones. The chelae and ancorae therefore begin as axes of the full, or about the full length; in the chelae the beginning is a straight or curved staff with shorter or longer axial bendings in either end, and tooth and alae arise gradually and grow to their full size. In tlie aneone the growth takes place in a similar way, but their teeth, as before mentioned, are perhaps not axial bendings, but arise in another way. Vosmaer and Pekel baring, in their paper from 1898 quoted several times in the preceding, treat and figure the development of the anisochela in A/, syrinx, but their discussion contains nothing new. When they conclude, on account of their having found chelae that were a little contort, we have therefore the right to say that cheke not only can be derived from spicula which have the shape of C, but indeed from spicula known as sigmata , this conclusion is unwarranted; developmental forms of the chelae are in no instance sigmata, and may always easily be distinguished from these; the fact that chelae may be contort, a feature that is much more frequent and may take place to a much higher degree than seems to be known by the authors, proves nothing at all. Developmental forms of the chelae have not rarely been misinterpreted. I shall here state the rases I have found. Carter (Ann. Mag. Nat. Hist. 5, IX, PI. XI, fig. 17 d and h) calls these two figures with a query bihamates ; they are developmental forms of an anisochela. He calls (ibid. 5, XV, PI. IV) fig. 3 d bihamate-like spicule ; it is the developmental form of an arcuate chela. Fristedt (Kgl. Sv. Yet. Akad. Handl. 21, no. 6, Tab. Ill) calls fig. 3 h spieulum c-eurvato-obtusum , but regards it with a query as an undeveloped chela; it is an undeveloped arcuate chela. Lambe (Trans, of the Roy. Soc. of Canada, XI, sect. IV, PL II | calls fig. 4 e a sigma; it is a developmental stage of a palmate anisochela. Levins en, in his paper from 1893 several times quoted above, after having established the fundamental difference between chelae and ancorae, and rendered an account of the fact that they are never found together, expresses the opinion that this fact must involve the alteration in the system that species with chelae and species with ancorae cannot be kept in one genus. I can fully agree with this view, and therefore in the present work I have separated the species according to it. In this PORIFERA. II. respect the question is for the present only of the genera Myxilla Lissodi ndoryx and Desmacidan Homoeodictya\ the particulars will be found under these genera. With regard to the examination I shall only add the further remarks that the examination of the structure of the skeleton has generally been made on dried preparations placed in xylol in not too thin sections, by which means distinct and complete views of the skeleton arc obtained. Care must be taken, of course, that the skeleton is not distorted by the drying. I mention this proceeding, because I think it gives a better and more distinct view than is got when the sponge is cut in a moist state, and by the use of my descriptions of the skeletal structure it must be remembered that they are made from such preparations. For the examination of the structure of the spicules I have generally used Canada balsam-preparations; in a few cases 1 used Naphtalin-a-monobromatum, which proved to be very good when the question was of very thin silicious plates; also a mixture of Naph- talin-a-monobromatum with Canada balsam was in some cases found to be good. Storax resolved in benzol and alcohol has been used in a few cases; but in by far most cases Canada balsam proved verv efficient; when the spicules are completely cleaned, it will in balsam-preparations almost always be possible to study the structure to the finest details. Fam. III. Desmacidonidae. Subfam. i. Mycalinae. Group, i. My caleae. According to what has been shown by Thiele (Abhandl. der Senckenberg. nat. Gesellsch. XXV, 949) the name of Esperella Yosm. must be altered to Myotic Gray, and consequentl} the name of the subfamily and the group will also have to be altered. Esperiopsis Carter. The form varying; incrusting or irregularly solid, but frequently erect and leaf-shaped, or in other ways symmetrical. The skeleton may be constructed in various ways; in the erect forms it may consist of long, well developed and branched fibres, but in the solid forms and in the incrusting otn gets a halichondroid or rcnierid structure. Spongin is most frequently present, the amount vary: rata: Megasclera monactinal, styli or subtylostyli ; microsclcra; the characteristic microsclcra are isocluhr falmata7, which may occur in one or several forms ; to these may be added isochclte arcualu. sigmat one or more /onus, toxa, or forcipes in different combinations. The genus Esperiopsis was establised b) Carter in 1882 (Aim. Mag. Nat. Hist 5, IX. 296) the species villosa, which lie had originally referred to Esperia. The distinctive charactei of the genus is the tact that the characteristic microsclcra are isochelse, which was also the principal reason win Carter separated the species into a particular genus; to be sure lie mentions also some otlui features, but they are of no consequence. Levinseu (Studier over Svampe-Spicula: Cheler og Ankere; Yideusk. 8 PORIFERA. [I. Medd. nat. For. Kobenhavn for 1893.1894, 11) says that there is no reason to keep the genus, as in the old genus Mycale (Esperella o/i»/j we have now exclusively anisochelae, now exclusively isochelae, and sometimes a mixture of both, and as the difference between an isochela and an anisochela may be very slight. I think, however, that there is good reason for keeping the genus, as the characteristic micro- sclera in Mycale are anisochelae, and small isochelse seem to be of very rare occurrence in this genus. Carter (1. c. 298) mentions this fact in a general way as occurring in some Myc ^/c-species , among which he only mentions At. plumosa Cart, and Ridley and Dendy (Chall. Rep. XX, 65) state it with regard to M. parishii Bow. in which species the small isochela is of a particular structure1). With regard to the other objection made by Levin sen to the keeping of the genus it is to be said that the anisochelae, to be sure, may approach isochelse as to form, but no species is known, however, with regard to which there can be any doubt in this respect. The Apycalc-species most closely allied to Espcriopsis, and more particularly to the Esperiopsis-species with renierid skeletal structure, is perhaps Mycale ovulum O. S., in which some of the anisochela; may show only slight difference as to the size of their ends, but the ends however are never of quite the same size. Another question is whether all the species for the present referred to Espcriopsis, are naturally closely allied. The species show great difference, as well with regard to form as to skeletal structure; also the combination of microsclera is varying to some degree, and rather many different forms may occur. To get a general view I shall put together, as far as possible, the described species with a statement of their microsclera; with regard to the species of Bowerbauk I follow, with a few excep- tions, the interpretations of Topseut (Revue Biol, du Nord de la France, VII). E. (Isodictya) Edwardii B Isochelse palmatse. - ( — j Normani B - 1 i fucorum Johnst - 1 ) Aldcri B - ( — ) scitida B - 1 1 involuta B — - ( — ) liispida B — ? - ( Halichondria) compressa B — ? - ( ) Thompsoni B - (Amphilectus) kispidula Ridley Challcngeri R. and D - profundi! R. and D - anomala R. and D — - coin wnata Tops — - rigida Lambe — ') Carter, as is well known, thought these small isochelse to be developmental phases of the anisochelae. He puts forth this theory in 1S74 (Ann. Mag. Nat. Hist., 4, XIV, 102), and here he figures for M. aegagropila Johnst. the typical aniso- chela, as also some small bodies situated in cells, which bodies he interprets as isochelate developmental phases of the aniso- chela. Levinsen (1. c. 9) has been of opinion that the question was here of small arcuate chelas. As there is, however, every reason to suppose that Carter has really had before him M. aegagropila (he mentions one of Johnston's original specimens 1, and as in this species no small isochelse are found, it is not possible to decide, what Carter has seen, and his figures are not to be explained. Developmental phases of anisochelae they cannot be, as those have a quite different appearance. PORIFERA. II. A. vancouverensis Lambe .... [sochelae palmatae. - quatsinoensis Lambe - laxa Lambe - rugosa Thiele - pedicellata mihi - (Isodictya) collina B sigmata. ?- (Halichondria) rigida B. ... Isochelse, sigmata. (If this species proves to be an Esperiopsis, rigida Lambe will have to change its uame). - cylindrica R. and D Isochelse palmatse, ?toxa. - symmetrica R. and I) sigmata of two tonus. - typichela mihi of two forms. - pulchella R. and D — of two forms, isochelae arcuatae. - pr&dita Tops isochelae arcuatae, sigmata. - villosa Cart of three forms, sigmata. - fiagellum mihi of two forms, sigmata, sigmata flagellata. - decora Tops of three forms, - forcipula mihi isochelae arcuatae, sigmata, forcipes. - polymorpha Tops Isochelae arcuatae, sigmata of two forms, toxa (small, sharply beut). - Schmidlii Arnesen — sigmata. - glomeris Tops ?- (Holopsamma) turbo Cart. . Isochelae. Dendy, after having found isochelae in this verj deviating form, refers it to Esperiopsis. Halichondria foliata Bow., which Topsent, in the mentioned work, refers to Esperiopsis, is an Echinoclathria\ the same holds good of Esperia folia to Frstdt. In the generic diagnosis I have given as characteristic microsclera isochelae palmatae; as will be seen, three species deviate from this rnle, viz. polymorpha Tops., Schmidlii Arnesen, and glomeris Tops, which have, as to chelae, only isochelae arcuatae, which seem to be of quite typical form. As above mentioned, however, the difference between chelae palmatae and arcuatae is not quite sharp, and pei haps it will be necessary only to say that the characteristic microsclera of the genus are isochelae. I shall still add that Ki eschnick (Semon: Zool. Forschungsreiseu in Austral. Band V, Denkschrift. Med. Nat. Gesellsch. Jena, Bands, 1900, 572, Taf. XLIV, Fig. 12, Taf. XLV, Fig. 51—52) has established a species, E. viridis. As the other species mentioned in this quite useless work it is unrecognizable, but it seems most nearly to be a Chondrocladia-species. Of microsclera are mentioned isochelae with six teeth (the very bad figure shows seven), and smaller isochelae with five teeth (to which a quite useless figure) 1. E. villosa Cart. PI. I, Fig. 4. PI. VIII, Fig. 1 a— i. 1874. Esperia villosa Carter, Ann. Mag. Nat. Hist. Ser. 4, XIV. 213, PI. XIII, figs. [3 15, PI. XV, fig 1:879 Unknown sponge Carter, Journ. of the Roy. Micr. Soc. 11, 502, PI. XVII a. fig. 1 sa,b, 1 1882. Esperiopsis villus,/ Carter, Ann. Mag. Nat. Hist. Ser. 5, IX, 296. The [ngolf-Expedition, VI. _\ [0 PORIFERA II. 1887. Esperia villosa Fristedt, Vega-Exp. vetensk; Iakttag. IV, 451, PI. 25, figs. 33— 39, PI. 29, fig. 19. 1904. Espcriopsis villosa Topsent, Resultats des Camp. Scient. du Prince de Monaco, Fasc. XXV, 211, PI. XVII, fig. 2 a-c. Erect, more or less irregularly leaf-shaped. The surface finely shaggy from projecting spicules; the dermal membrane thin, with no .separate skeleton, resting on spicules that are spread in a peni- cillate way. Oscula formed as small, conical projections, along the upper edge or a little down on the surface. The skeleton consists of polysplenia r fibres branching up through the sponge and anastomosing; from this skeleton shorter fibres go off to the surface. Spicula: Megasclera styli or slightly marked sub- tylostyli o-6 — 0-7 j"""/ microsclera of four forms : isochela* palmate? of three forms, large ones of a parti- cular narrow form o~o8 — o'i2mm, middle ones o'oyS—o-og2n"" , small ones o'osi — croj/'""': sigmata, large 7 ■,- — irig""". This species has been pretty well described by Carter with the only misconception of the mutual relation of the three different chela;, which is a consequence of his wrong interpretation of the growth and development of these bodies. The species seems most frequently or always to be erect and more or less leaf-shaped, but is otherwise of somewhat varying form and thickness, and frequently of an irregular appearance. With its base it is fastened to stones or some other uuderlayer, and most frequently its base is widely spread. The largest specimen in hand is of a height of ca. i3c,n and a thickness of about 15 — 20mm. The colour (in spirit) is generally gray, sometimes passing a little into brownish. On account of its skeleton the sponge is rather firm, but may, however, be torn easily, and all the specimens are much damaged. The surface is finely shaggy on account of the projecting spicules. The dermal membrane is thin, with no skeleton, supported by spicules projecting in a fanshaped wax. The pores are situated in the dermal membrane between the projecting spicules; sometimes they are very close-set, so that the membrane becomes a network. They are round to oval, and their size is generally between 0-02 and o-i5mm. Oscula are constructed in a peculiar way; along the upper edge of the sponge, or sometimes a little down on the surface is found a number of projections quite slightly conical ; they are of an average height of a few mm., and have a diameter not exceeding imm. They consist of spicules and are apparently solid, but when cut off at the base they leave a hole, and are seen to be hollow in their lower part; in a few of them a little opening is also found in the top. All the oscula (they are only found distinctly in the best preserved specimen) may be supposed to be shut, open oscula were not seen. Further down on the sponge a few round holes are seen, which I take, however, to be due to damaging1)- From the osculum a canal may generally be traced Some way down in the sponge. The skeleton consists of irregularly branched, polyspicular fibres, branching from the base up through the sponge, and frequently anastomosing. They are thickest in the lower part of the sponge; in the middle of the sponge they have an average thickness of ca. o-35mm; they are polyspicular, and have a great number of spicules side by side. The fibres with their anastomoses form a rather dense and solid skeleton. From this skeleton close-set fibres go off to the surface generally curving some- what upwards. These fibres divide on the way to the surface, and pierce the dermal membrane as i When Carter (1. c. 1S74) says: « Vents scattered here and there irregularly , it is presumably owing to the fact thai his specimen has been damaged, and the real oscula have been wanting or indistinct. PORIKERA. II. J( bundles of spicules spread in a more or less fan-like or perricillate way; the fibres are generally of a length of 3 -4mm. The dermal membrane is supported by the projecting bundles of spicules, and is provided with no skeleton of its own. The fibres and bundles of spicules that support it, are. however. often far from being perpendicular on the surface, and accordingly, when a piece of the skin is viewed under the microscope, it may appear, as if there was a reticulation in the skin, the fibres under it being also seen. In the fibres of the skeleton some spongin is seen, which, although not abundant, coats the fibres completely. As mentioned above the fibres are thickest at the base oj the spini^. and the spongin is also most distinct here. Below the fibres pass into a thin basal membrane tunned b) spongin, and provided with scattered spicules; it is directly fastened to the substratum, from which it is easily separated, and then it shows a smooth surface. Spicula: a. Megasclera arc styli or very slightly marked subtylostyli ; most frequently the) are straight, sometimes quite slightly curved. They are thickest in the middle, and thus a little fusiform. the greatest thickness being not rarely nearest to the pointed end. The point is evcnh tapering, but not long. Most frequently they are slightly restricted a little below the rounded end. and thus ap- proaching to subtylostyli, but the restriction is not rarely imperceptible or wanting. The length is between e/6— 075""", most frequently approaching the latter size; sometimes it may go down to us"11". The thickness is between ca. 001 — cro2mm. Finer spicules, developmental forms, occur, but in ver\ small number. The specimen described by Top sent I.e. has somewhat larger megasclera; they are stated to be 0-935— o-g8o'nm. b. Microsclera : Of these are found isochelse palmatse of three different forms, and sigmata. 1. The largest chelae are of a peculiar shape, Carter calls them weaver's shuttle- like ; they are narrow, the side-edges of the two ala; are parallel, and the alse continue far down along the shaft, so that only a short space is left in the middle where the cylindric form of the shaft is seen. The shaft is straight. The side-edges of the tooth are likewise about parallel, or slightly converging towards the end, and the end of the tooth is rounded. When the tooth is seen from the front, it appears to have a thickened edge, but this is owing to the fact that the sides are curved inwards. When the chela is viewed from the side, it is seen that as well the sides of the tooth as the ake on the shaft are curved inward so as to meet each other at the end- of the chela. Seen from the side the tooth most frequentlv bends a little outward at the end, while the outermost point is again bent inward in a claw-like way; the latter bend, however, is in so far onlj apparent, as it i- owing to the bending in of the edge. The edge of the tooth being thus bent inward all round the tooth becomes hollow on the inward side. The tooth is generall) of about the same length as the alse, and its position is about parallel to the shaft. At its basal end the axis is seen as a little oval tubercle. These chela; are sometimes somewhat twisted. The length is rather varying, from (S"'"\ and the thickness varies in proportion from o-onm,n to o-oo2mm. Monstrous forms of sigmata may occur, and especially one form is not rarely seen, in which one end is split into two or more points, as figured by Fristedt I.e. fig. 39. Besides sigmata are found quite singly some bodies which I must suppose to be developmental forms of sigmata; they are curved like the axis of a sigma, and the ends are tapering, but they are quite, or to a higher or smaller degree, wanting the recurved ends. They have been measured of lengths from 0-058 — o-i8mm with thicknesses from o-ooi— o-oo25n,m. Thus this sigma seems to reach a considerable thickness, before its ends are properly developed. Embryos. In some of the specimens embryos were found scattered in the body of the sponge, sometimes singly, sometimes several ones together. They were roundish, of a diameter of about iran'. Their speculation shows some peculiarities. Of megasclera they have very fine styli, generally with PORIFRRA. II. ,-, a somewhat swollen upper end; they were measured to a length of 0*25 o,30,nm and a thickness al the upper end of ea. croo2m'". Of microsclera they have onlj the middle form of chelae, which occur in all stages of development, as also fully developed, but they are considerably smaller than in the fully developed sponge, only reaching a length of ■). Quite the same observation has been made by Ridley and Dendy with regard to the embryos of Esperella mammiformis, where the aniso- chelae of the embryos had a length of o-05mm, while in the grown sponge their length was oxyjmm. In the opinion of these authors this fact, however, has no especial peculiarity, as, according to their view of the growth of the chela, the small chelae may quite simply grow to their full size. The specimens with embryos were taken during the month of Jul}'. Locality: Station 28, 650 14' Lat. N., 550 42' Long. W., depth 420 fathoms; station;;. 62 58' Lat. N., 23 28' Long. W., depth 486 fathoms; station 81, 61° 44' Lat. N., 27 00' Long. W., depth 485 fathoms; station 127, 66 33' Lat. N., 20° 05' Long. W., depth 44 fathoms. It has further been taken on 65 39' Lat. N., 28: 25' Long. W., depth 553 fathoms (the East-Greenland expedition 1891 -92). Altogether five or six specimens. The mentioned localities are situated to the north and south of Iceland, in the Denmark Strait and in the Davis Strait. Geogr. dislr. Between Scotland and the Faroe Islands, depth 440 fathoms ( Porcupine .Carter-: the eastern coast of Greenland, depth 140 fathoms (Fristedt); at the Azores, depth 1196 fathoms iTop- sent). Carter's Unknown sponge is, no doubt, identical with E.villosa, it was taken by the Porcu- pine , between Scotland and the Faroe Islands, 59 56' Lat. N., 6° 27' Long. W., depth 363 fathoms; but it is to be noted that the bottom temperature was here — 030, while on all the other localities of the species it has been positive. 2. E. Normani Bow. PI. VIII, Fig. 2 a— d. 1866. Isodictya Normani Bowerbank, Mon. Brit. Spong. II, 320,31, III, 141, PI. LVI, figs. 1 5. 18S0. Amphilectus Normani Vosmaer, Notes from the Leyden Museum, II, 117. 25. 1885. Esperia Normani Fristedt, Kgl. Sv. Akad. Hand., 21, No. 6, 42. 1893. Esperella Normani Levinsen, Det vidensk. Udbytte af Kanonbaaden Hauch s Togter, 422, 19, Tab. I, figs. 37-49. Incrusting or ///ore or less massive or cushion-shaped (sometimes somewhat branched). The dermal membrane thin, without spicules, resting on the skeleton below: it is pierced by the ends of the fi; and the surface therefore is finely shaggy. Oscula sea/lend, most frequently on the cue, fitly marked, conical projections. The skeleton oj a renierid structure with polyspicular primary fibres and most frequently single transverse spicules. Spicula: megasclera curved styli 0-16—0-2$""" ; microsclera one form, isochelcz palmataz 0-020 — 0-021'""'. The typical form of this species is incrusting, especially on Hydroidea and branched I'- ll may be of varying thickness and consequent!) somewhat varying in form: most Erequenth forms larger or smaller covers, or it Incomes cushion-shaped or lumpy. It seems, however, also to 'i As all spicules are of tin same si/..-, or. at all events, of about (lie same size 111 small ami large specimens of .me species, it is to be supposed that verj soon alter the sponge having fixed itself, 11 the size normal to the species. , , TORIFKRA. II. able partiv to assume a tree, branched form, as stated by Levinsen I.e. The specimen of Levinsen, however, has incrusted a Hydroid, and presumably its form is partly owing to this fact; but the speci- men has also free branches, in which nothing of the Hydroid seems to be found, as also the primary fibres of the branches may be found running longitudinally, -while, if the question was of a cover, they would have to be supposed to run from the middle, from the body incrusted, perpendicularly on the surface. The largest specimen in hand has a greatest extent of ca. 75mm. The colour (inspirit) is light yellowish. The consistency is rather loose and soft. The dermal membrane is thin and transparent without spicules; it is supported by the skeleton below and pierced by the ends of the fibres, conse- quently the surface is finely shaggy. On account of the apertures of the incurrent canals shining through, the surface gets the netlike appearance, as is found, for instance, in most Reniera-species. The pores are very close-set in the dermal membrane, so that it is reduced to a network; they are round and of an average size of 0-05 — oi""". Oseula are scattered on the surface; they have generally a diameter of from a little more than one to 3"""; they are situated on the top of more or less marked, but always low, flatly conical projections. The skeleton is of a renierid structure. It consists of fibres running from the base towards the surface where they pierce the dermal membrane. These fibres are polyspicular, and they have generally, as stated by Bowerbank and Levinsen, about three spicules in breadth; sometimes also a little more. The transverse fibres are almost always only represented by single spicules, they form no coherent fibres, and the)- are situated very irregularly. The distance between the primary fibres is on an average ca. o-i5mm. In the deeper layers of the sponge the skeleton is irregular, and here no distinction can be made between primary and secondary fibres. Spongin is found in the skeleton, especially distinctly in the nodes, but it is white and exceedingly clear, and therefore not easilv observed. Spicula: a. Megasclera are somewhat curved styli; most frequently the curye is even, only rarely it is a little sharp; it is generally found in the middle, sometimes nearer to the head-end; the opposite end is evenly and rather long tapering. They are somewhat varying in length, partly in one individual, and partly in different individuals; upon the whole the length of the styli in the specimens in hand is between 0-16 and 0-25""". Also the thickness is varying, and is between ca. 0-0057— o-oii4mmi). Such is the thickness of the spicules that seem to be fullgrown, but developmental forms of every thickness down to quite fine ones are also found; they are only very little shorter than the fullgrown ones. b. Microsclera; these are only found of one kind viz. isochelfe palmatse; they are a little curved, but the middle part of the shaft, between the alse of the two ends, is straight or .-sometimes slightly curved inwardly; this middle part is about one third of the length. The tooth is o! about the same length as the alse, and its breadth is like that of the alse taken together. On the >ides the tooth and the alse bend towards each other, but when the chela is viewed from the side these recurvings, on account of their fineness, are almost not to be distinguished. The length of the chelae is 0-020— 0-02 imm, and their breadth is ca. o-oo57mni. Of the chelse developmental forms are found; the youngest one observed appears as a thin staff with rather long recurvings in both ends, without ') In some specimens the needles have an average length of 0-23 — 0-25™'" with an average thickness of o-orm">; in others the length is on an average 017- o-20mn> with a thickness of o-oo7m"i. PORIFERA. II. ,r or almost without any beginning of the alae or of the plate of the tooth. The developmental forms have the same length or about the same length as the fullgrown ones. Tin- chelae are found through- out tlie sponge, and in no small number in the dermal membrane. Locality: The Faroe Islands, q miles to the east of the Nolso revolving light, depth ea. 30 fathoms; 6 miles north and to west of Kalso, depth 60 fathoms (Th. Mortensen); the Westmann Islands iSsemundsen). >Six specimens or fragments in all. Geogr. distr. The species is hitherto known to the south as far as the Channel, Guernsej (Bowerbank), Luc and Le Portel (Topsent); farther north it has been taken off Bohuslan (Fristedt), and in the Cattegat on depths from 61 , to 10 fathoms (Levinsen). 3. E. sp. (?Alderi Bow.) PI. VIII, Fig. 3 a— c. We have a quite small specimen of an Esperiopsis-species sitting on a worm-tube, which specimen has a skeletal structure similar to that of the preceding species. The primary fibres have a few more spicules alongside each other, and they also pierce the dermal membrane, so that the sur- face is shaggy; but the spicules are different. Megasclera are styli, most frequently rather strongly curved and with an evenly tapering, rather long point. Their length is between 0-38 and 0'44mm, and the thickness is about o"oimi". Microsclera are isochelee palmatse of a similar structure as in the pre- ceding species, but they are straight or almost straight; besides they are a little larger, their length being 0-025 — GroaN""" and the breadth ca. 0-07""". Also of these chelae developmental forms were found of the same appearance as in the preceding species. The cheke of this species show a peculiarity, which, however, is not found in all of them, and which may be more or less marked where it is found. It consists in the fact that the recurved final part of the axis, which must be supposed to run along the middle of the tooth, some way down the tooth bends off from it inward, ami, when the chela is viewed from the side, appears a- a projecting point or knob on the inside of it; when the chela is viewed from the front it appears through the tooth as a little tubercle close to the edge. As mentioned, the feature, hovewer, is far from being a constant one, in some of the cheke it is not found, and it may also be found singly in other species. -- l.ambe (Proceed, and Transact of the Roy. Soc. Canada, X, [893, Sec. IV, p. 68seq.) has described four Esp species, which, to judge from the figures (no mention is made of it in the text), have chelse, in which the mentioned structure i.s strongly marked. As is well known, the same structure is again found in the chelse of the genus Homoeodictya^ ami this genus or subgenus has been established just on this structure. The Esperiopsis-species showing this structure of the chela, to be sure, are closely allied, but as the character does not seem to be a constant one, it can here scarcely be used as a generic mark Locality: St. 127, 66° 33' Lat. N., 20 05' Long. W. ; depth 41 fathoms. Geogr. distr. E.Alderi Bow. is from Northumberland. Note. The Esperiopsis-sipecies placed 1>\ bowerbank under the genus Isodictya, appeal to be closely allied, and there is a great probability that Bowerbank has established too many species, but it will not be possible, without a close examination of the type specimens, to unravel the species; l6 I'ORIFERA. II. Vosmaer refers KAlderi as a synonym to Normani, and also Topsent has made considerable re- ductions, ami has Eor instance referred Aldcri to fucor um, hut for the present nothing can be said of the correctness of these identifications. When I have thought that the present species might possibly he Alderi, the only reason has been the size of the spicules; the peculiarity of the structure of the chelae would scarcely have been observed by Bowerbank. 4. E. pedicellata n. sp. PL I, Fig. 2. PI. VIII, Fig. 4 a-c. Erect . stalked, somewhat club-shaped ; the upper part lobate or winged. The surface slightly shaggy; the dermal membrane thin. The skeleton an irregular network of polysplenia)' longitudinal fibres and irregularly scattered spicules. Spicula: Mcgasclera styli 0-35 — u-g^'"m; microsclcra of one form, isocheliT palmattB "'"/j — co/j""". The contour of this species, of which we have only one specimen, is most nearly club-shaped; below it passes into a stalk attached to a shell of Astarle crenata Gray. The form is otherwise irregular, the upper part being provided with irregular, broad and deep furrows running longitudinally, between which are found lobes that may be so compressed as to form wings. The length of the somewhat damaged specimen is 65""", and the greatest breadth is 25mm. The consistency is rather firm, almost flesh\'. The colour (in spirit) is something between gray and brown, approaching to olive colour. The surface of the sponge, in the state of preservation in which we have it, is provided with projecting spicules, but by far the greatest part of the dermal membrane is wanting; to judge from the places where it is preserved, the sponge in its undamaged state is slightly shaggy. The dermal mem- brane is exceedingly thin and transparent. When it is torn off and examined it shows some irregu- larly scattered spicules, which thus seem to belong to the dermal membrane itself; otherwise it seems to be resting on the irregular skeleton below, and some spicules project through it. Neither pores nor oscula are seen, I suppose, on account of the membrane only being preserved in so few places. The skeleton consists of a rather irregular network; especially longitudinal fibres are found, the greater part of which are polyspicular and may be of varying thickness; they contain, however, always few spicules, and are not especially strongly marked In their longitudinal course some of them bend off towards the surface, which they meet at a very acute angle, and which, as far as I have been able to see, they pierce. Between the longitudinal fibres scattered spicules without any regular position are found, and transverse fibres are not formed. While in the upper part of the sponge the longitudinal fibres have a rather irregular course, in the stalk they run perpendicularly; they are here thicker and consist of more spicules, and some of the scattered spicules are placed trans- versally. Some spongin is found in the skeleton, especially discernible in the nodes, and it seems also sometimes to continue over the fibres; it is white and clear, and consequently only little conspicuous. In the stalk the spongin is more copious, and may be seen quite to wrap the polyspicular fibres. Spicula: a. Megasclera are rather large styli, more or less curved, sometimes almost straight; the place of the curve may he somewhat varying, and it is sometimes a little irregular. The styli are slightly fusiform, tapering somewhat towards the rounded end. The other end is evenly and long PORIFERA. II. ,- tapering. The size of the styli is rather varying, the length thus from 0-31 and the thick- ness in proportion from 0-012 to 0-024™"'; the smaller ones are the least frequent Developmental forms occur in small numbers down to quite fine ones; as the fullgrown needles the} are of varying length, b. Microsclera; these are only of one kind, isochelae palmatae; they are of the common structure, the shaft is slightly curved, but with a straight middle part, and this free middle part is about one third of the length of the chela. The tooth is somewhat narrower than the alse taken together. When the chela is viewed from the side the recurved lateral edges of the tooth and the alae are only to be seen with difficulty, and only tinder very high magnifying powers. These chelae are ven small, their length is 0-014 — 0-015""", and the breadth is 0-003"""; sometimes they are a little twisted. The\ are found copiously throughout the sponge and also in the dermal membrane. This species is closely allied to the E. columnata established by Topsent in 1892 (Resultats des Campagn. scient. du Prince de Monaco, Fasc. II, 90, PI. V, fig. 5, PL X, fig. 5); it is of a similai form, and also the skeletal structure may be taken to be the same. Further they agree with regard to tin- size of the spicules and in the fact that the styli are comparatively large, while the chelee are very small, as also in that of the styli being of the same form. Topsent states the measures of the stvli to be 075m,n with a thickness of o-oi6mm, and the length of the chelae to o-oiO""". On the other hand there is a difference in the structure of the chelae they being in E. columnata, to judge from the figure. considerably broader, as well when seen from the front as in profile. A measuring of the figure of Topsent gives as the greatest breadth, when seen from the front, 0-009""". Locality: Only one specimen from the Davis Strait, station 27, 64 54' Lat N., 55 eo' Long. W., depth 7,qT, fathoms. 5. E. forcipula n. sp. PI. I, Fig. 5. PI. VIII, Fig. 5 a -i. (Formed as a thick leaf?) The surface smooth, flic dermal membrane provided with spicuU / he pore side forming scula scattered. The skeleton con- sists of polysplenia fibres branching up through the sponge, between th, »i an irregular network. Spicula: Megasclera styli o- 54 — o'dS"""; microsclera of four forms, isochela: palmata- ooir — o-oiS""", isocheler ar- cuatct 0-038 — o'oj"""; sigmata nuij — o'oSj"""; forcipes o-oij""". y )f this species we have onl\ a couple of fragments, the largest of which has an extent in breadth of 40mm and a height of ca. 30"""; the fragments would indicate that they have belonged to a sponge that has been erect and formed as a thick leaf, perhaps about a- A. villosa, and in this cas< the fragments among other things show the upper part of the sponge. The colour (in spirit' is whitish yellow. The consistency is rather firm. The surface is somewhat wrinkled ami folded, but otherwise smooth. The dermal membrau, is thin, and on one side of the sponge where no pores are found, it is provided with spicules rather close-set, irregnl.u 1\ scattered, bin parallel to the -mi ( )n the other side of the sponge where numerous pores are found, the needles, on the other hand. are arranged as an irregular, polyspicular network round the pores. Oscula are simple, oval, 0; -01m what irregular openings of varying size in the dermal membrane. The spicules of the dermal mem- brane surround the oscular aperture, being arranged in .1 ring-like way round it. but at some distana Tli>- [ngolf-Expedition. VI. i, .1 [8 PORIFBRA. II. from the opening itself, which is thus surrounded by a narrower or broader brim (probably changing ording to the degree in which oscula are shut) of the membrane without styli. On the other hand, mieroselera, especially the smaller form of chelee, are found here in large numbers. Pores are only I. mud on one side of the sponge where the spicules are arranged in a net-like way; they are round or oval, and have been measured to a size of 0-03 — o-238'nm. As the pores are thus only found on one side it is possible that oscula are only found on the other, and this, perhaps, is again dependent on the form of the sponge; the fact cannot, however, be decided from the fragments in hand. The skeleton- consists of polyspicular fibres branching up through the sponge from the lower part and here and there anastomosing; in the upper part of the sponge they run as more or less parallel fibres. Here they all bend towards one side of the sponge, and run perpendicularly towards the surface. The consequence of this course of the fibres is that they are more or less parallel to the other side of the sponge. The side towards which the fibres bend, is the poreless one; they are here connected with the close-lying spicules of the dermal membrane, and support the membrane, but do not pierce it. The dermal membrane on the other side, which, as mentioned, is provided with pores, and the spicules of which form a reticulation, rests on the fibres running below it. The fibres are polyspicular, and consist of rather many spicules beside each other: they are of an average thickness of 009— o-i2mm. Between the fibres a quite irregular network is found, partly of fibres with few spi- cules, but chiefly of single spicules. In the lower parts of the sponge the longitudinal fibres are more close-standing than farther up. The spicules of the fibres are connected by a clear, not copious mass of spongin apparently, however, wrapping the whole fibre; it is especially distinct in the nodes. Spicula: a. Megasclera are styli; they are slightly curved in various ways, aud sometimes somewhat irregularly ; they may also be almost straight. They taper evenly, but most frequently not much towards the point, and the point itself is therefore most frequently more or less suddenly pointed and may be longer or shorter, down to quite short; it is frequently more or less distinctly marked off, and the marked off point may also be longer or shorter. The needles are often a little thinner below the rounded end than at the end itself, but they cannot, however, be designated as subtylostyli. The length is between 0-54 and o-68mm, and the thickness is o-oio— 0"Oi4inm; the thickest ones are generally not the longest. Finer, down to quite fine developmental forms are found, but only in small numbers; they are only a little shorter than the fullgrown ones, the finest ones have a length of o-47ram. The developmental forms are all long tapering, b. Mieroselera ; of these are found two forms of isochelse, smaller isoeheke palmatse aud larger isochela; arcuatse, further sigmata and forcipes. 1. The small palmate isochelse may be somewhat varying in form, the middle part of the shaft between the end parts being straight, or more or less curved; this part is a little more than one third of the length of the chela. When the middle part is curved the whole shaft forms an even curve; when it is straight, the end parts, from which the lateral alae go off, form obtuse angles with the middle part; the tooth being directed somewhat forward the angle between the tooth and the shaft becomes rather large. The tooth is of about the same length as the alse, but it is considerably narrower than these taken together, and is ovate; the lateral edges of the alee are refolded through the whole length, so that the folded part is seen, when the chela is seen from the front. These chelse are very small, their length is between 0011 — o-oi8ram, and their greatest breadth is o-oc>7mm. 2. The arcuate isochelae have PORIFERA. II ,c a rather slightly curved shaft, the lateral alae of which are pointed and tooth-like, and of the same length as, or a little shorter than, the tooth; the tooth may he narrower or broader, but, when viewed just from the front, it is lanceolate and more or less pointed. Tuberculum is oval, most frequently pointed, or lengthily triangular; when the chela is seen a little from the side, the tooth and tuber- culum appear more pointed. The length of the chela is somewhat varying, from in.^S""" to cro= the thickness of the shaft is ca. croc^"1"1. Most frequently these chelae are a little twisted, so that the two teeth are not quite in one plane. < >f this chela I have seen a few developmental forms, but only rather grown ones with half-developed tooth and al;e. 3. Sigmata; these are more or less contort; they reach to a rather considerable size, but are very varying in this respect, the length being between c>2— o,oo6""". These sigmata show an interesting fact well worth to be noticed. Towards the bendings the shaft geueralh shows a slight expansion as seen in PI. YJ 1 1, fig. 5 g); this is not owing to the shaft here being thicker, but to the fact that it is somewhat compressed. When a sigma is seen under the microscope, the hook that on account of Un- twisting is turned towards the beholder (in the figure the upper one), appears also narrower than the other, and the compression may also be seen on broken sigmata where a transverse section is seen; the transverse section seems to be somewhat triangular with the narrowest edge turned inward. 1 li these sigmata developmental forms of different thickness are not rarely found; the finer they are. the less developed are the recurved ends; in the very finest ones, of a thickness of scarcelj O'COI""11, the recurved ends are not vet formed. The mentioned structure of the end parts of the shaft may already be traced in the developmental forms. 4. Forcipes; these are of the common, more or less hairpin-like, form with a round curve above and two more or less parallel legs; the legs are most frequently slighth diverging, but may also be cpiite parallel, or slighth' converging, the latter, however, being perhaps only apparently the fact and owing to a twisting. They are thorny, which is, however, on account of their smallness, only very little conspicuous; the legs end in a quite small knob-like swelling. When the forcipes are seen under sufficiently great magnifying powers the thorns are seen to be found especially on the inner side of the legs; they are comparatively long, and directed a little upward; also on the upper side of the curve some smaller thorns are found, and there seems likewise most frequently or always to be found a small thorn on the inner side of each knob. A slight granulation may also in most cases be seen on the other parts of the forceps. Sometimes the legs are not oi equal length. These forcipes are exceedingly small and may easily be overlooked. Their length is OW the thickness at the curve, where it is greatest, is ca. cvooimm; quite few, somewhat larger forcipes were seen. The microsclera are found as well throughout the tissue as in the dermal membrane; in tin tissue sigmata are of most frequent occurrence, while in the dermal membrane the two tonus of chela- seem to be found most frequently. Locality: The Davis Strait, depth Sn-u»i fathoms (Th. Holm), a couple of fragments, Remarks: This species has a quite interesting spiculation, and it is the first Es/>criopsis-Sf>ecies, in which forcipes have been found. Therefore there might be souk- doubt with regard to its being referred to this genus, and there might be a possibility of referring it to Forcepia Cart. As. however, the species has no special dermal spicules, and thus wants a character very significant to the Myxillrer, PORIFERA. II. and as forcipes also occur outside of the genus Forcepia, and the occurrence of these bodies therefore scarcely alone is sufficient for the establishing of a genus, I think it most natural to refer the present species to the genus Esperiopsis. Topsent (Resultats des Campagn. scient. du Prince de Monaco, Fasc. II, 1892, 100, PI. VI, fig. 5, PI- X, fig. 9) has established a species Force pia versatilis wanting dermal spicules: but in embryos found in the sponge small diactinal spicules were found which Topsent takes to represent the dermal spicules, but they are not further developed, so that the species later on has none of them. This species, however, is no Forcepia, but an Asbestopluma, as will be more particularly mentioned under this genus. 6. E. flagellum n. sp. PI. IX, Fig. 1 a— h. Incrusting; the surface slightly uneven from projecting bundles of spicules; the dermal mem- brane thin without spicules. The skeleton irregular consisting of polyspicular fibres and bundles of spicules. Xo spongin. Spicule/: Megasclera styli o-jg — o-j-f""" : microsclcra of four forms, isochelm palmate of terms, large ones ten-/,? — iro (Bull.de la vSoc.de France, XXI, 147, fig. a— d), which the authoi in u>.>| in the work qui above (223, PI. XVI, fig- 5, PI. XVIII, fig. 7) refers to Hamacantha. The sigma occurring in the present species is of a quite similar form as those of the mentioned two G<7/««-species, the onh difference being that in the latter one arm is generalh longei than the other, while in the presenl species both 22 PORIFERA. II. arms are of equal length, in which feature this sigma quite agrees with those of as well E. decora as H. clavisapta. It is also of some importance that the developmental form of this sigma has been found here, as it has not been known before. Locality: lugolf, station 55, 63 33' Lat. N., 15' 02' Long. W., depth 316 fathoms. Only one specimen. 7. E. typichela n. sp. PI. I, Fig. 3. PI. IX, Fig. 2 a — c, Figs. 3 — 4. fnerusting, the surface with very small, close-set, conical projections, and with scattered long, Hagellifornt appendices; the dermal membrane thin, without spicules. The skeleton consists of polysplenia r h 'bres, chiefly running from the base to the surface. Spongin wanting. Spicula : Megasclera styli o-jj — o\/5"""/ mtcrosclera, isochelce palmatoint they grow fewer, and at the very end they are quite few, in quite undamaged appendices per- haps only a single one. In the covering layer of tissue an abundance of microsclera is found; along the fibre, at least to the middle of it, the large chela is arranged in beautiful rosettes, and between these rosettes the little chela is found in dense crowdings (PI. IX, fig. 4), but forming no rosettes. The sponge is throughout highly intervowen with sand and small silicious particles. Spicula: a. Mcgasclera are very slender, straight styli; they taper evenly, but not much, towards the pointed end, the point itself is rather short. The length varies from 0-33— (.r.15""", and the thick- ness from 0-004 >>'(»57mm. Finer developmental forms are found, but only singly, b. Microsclera are two forms of isochelse palmatae. r. The large chelae are of a very regular and beautiful form. The shaft is straight, the free middle part a little curved inward. The alae reach so far down the shaft. that the free middle part is only about one fourth of the length, and their sides are somewhat refolded. The tooth is of the same length as the ake and only a little narrower. Its edge is curved a little inward. Tuberculum is longish, broadest below. When the tooth is seen from the inside the axis may be seen some way down it. Not rarely a slight twisting of the chela is observed. The length is 0^064 — 0'075ml", and the breadth is o-02imm. A few developmental forms of this chela were seen. 2. The small chela lias a quite slightly curved shaft, the end parts are so long, that the free middle part of the shaft is quite short. The lateral edges of the ake form a far more curved line than in the large chela, and their lower edge is straight. The sides of the alee are somewhat refolded. The tooth is of the same breadth as the alse, and the tuberculum is a little longish. The ahe and the tooth form a very small angle with each other. The length is 0-021 — o-025mm, quite singly specimens were seen of a length of o-035""". The breadth is o'OOiS""". The occurrence of the chela; is quite singular; to be sure they are to be found throughout the tissue, but especially at the surface. The large chela occurs as rosettes which seem to be attached to the fibres, especially at the dermal membrane, but not in this membrane itself. It is seen arranged in rosettes in the layer of tissue on the projecting ends of the fibres. Also the small chela; are especially seen at the surface; the) do not form rosettes but occur in groups or dense crowdings. Both kinds of chelse occur also, as before mentioned, in tin llagelliform appendices. The occurrence of the large chela in typical rosettes is rather interesting, .is this fact is otherwise not known in the isocheke, but lias only been observed in anisochelae. Cai mentions rosettes of chelse in Mycalc litubans, and thinks here to have found isocheke in rosettes; as will be mentioned hereafter, under the species in question, its chelae, however, are anisochelae. This species shows itself to lie related to the preceding one; the megasclera are of the same form, and also the large chela is of the same structure. Also the skeletal structure seems to be the same as well with regard to the arrangement as to the fact that spongin is wanting. On the other hand the small chela is of a different structure, and no kind of sigmata is found. Locality: Forsblads fjord. East Greenland, depth 50 90 fathoms (the A.mdrup-Expedition 1 ( >nly one specimen. Mycale < «raj . The habitus may pass through tin ivhole series oj forms from thinner or thicker incrustations through massive forms to erect, oft on lobate, or finally branched or more or h thirty leaf- or cuf-slio 34 PORIFERA. II. forms that will then be more or less symmetrical. The skeleton consists of poly spicular fibres ; in the erect tonus it is well developed, often dendritically branched, in the massive and incrusting forms it max be oj renierid or more irregular structure, or il may in the incrusting ones consist of slightly branched fibres running from the base to the surface without transverse fibres. Spongin is most frequently found, in varying, frequently only slight amount. Spicula: Megasclera monactinal, styli or subtylostyli ; microsclera; the characteristic microsclera are anisochelcB palmatce of one or more than one form, tlic largest ones often in rosettes: to these may be added sigmata, trichodragmata, toxa, and. rarely, small isochelce palmata. The genus Mycale, like Esperiofsis. passes through a series of forms from thin incrustations t<> erect, rather symmetrical forms. The development of the skeleton is connected with this fact. The lowest skeletal structure I take to be the one occurring in some thin, incrusting forms, and consisting of fibres running from the base to the surface and sometimes slightly branching, as has been described and figured by Vosmaer and Pekelharing with regard to M. aegagropila (Verhandl. d. Koninkl. Akad, v. Weteusch. te Amsterdam, 1898, 2, VI, No. 3, PI. I, fig. 3—4). The fibres are here quite free without connecting transverse fibres or transverse spicules. This structure quite without transverse fibres is, perhaps, owing to the fact that these sponges are quite thin crusts. When we get to thicker or massive species, transverse fibres or transverse spicules are found, and the skeleton gets a renierid or more irregular structure which in the erect forms may pass to a dendritic structure. The typical il/yr^-anisoehela, as ^ ^s f°nnd for instance in lingua and placoides, is a very characteristic one distinguished by reaching a rather considerable size. It may vary very much in size without showing distinctly marked, different sizes, but it may also occur in several well-marked sizes or forms; the largest ones very often occur in rosettes, which is not known to be the case with regard to the smaller ones. Small isocheke may occur, but rarely, for instance in M. farishii Bow., where they occur together with anisochelas, sigmata, and trichodragmata, and in J/, plumosa Cart., where, according to Carter, they occur together with anisochelae, sigmata, and toxa. Also sigmata may be found of more than one size, for instance in J/, macrosigma Lindgren. The microsclera mentioned in the diagnosis may occur in different combinations. In some species only auisochelse are found, either of one or more than one form, further chela; and sigmata, chelae, sigmata, and tricho- dragmata, which latter combination is very frequent, then chelae, sigmata, and toxa, or chelae and trichodragmata; finally, as mentioned, small isochelaemay in a few7 instances be added to the combination. 1. M. placoides Cart. PI. IX, Fig. 5 a-1. [876. Esperia placoides Carter, Ami. Mag. Nat. Hist. Ser. 4, XVIII, 316, PI. XIII, fig. 12, PI. XV, fig. 32. i-s's". Vosmaer, Notes from the Leyden Museum. II, 147, 32. [892. Esperella placoides Topsent, Resultats des Campagn. scient. du Prince de Monaco, Fasc. II, 89, PI. I, fig. 15. Erect, somewhat club-shaped, sometimes compressed or more irregular. The derma/ membrane thin, without spicules, pierced by projecting spicules, and the surface consequently finely shaggy; it is provided with sinuous or bran died fore-furrows. Oscula in the upper part of the sponge on the fop of PORIFERA. II. ,, small oscular cones. The skeleton consish of poly spicular fibres branching up through the y The spicules piercing the dermal membrane are smaller than the other spicules oj the skeleton. Spicula: Megasclera styli or subtylostyli, sometimes with the upper end formed like a handle; the styli of the skeleton u^jj — trjij""". those of the dermal membrane o-j- try"'": microsclera of three forms, an palmato- 0-025 — o-op2mm, the la>gc ones frequently in rosettes; sigmata 0-017— o-o2jmm; rhaphides in trichodragmafa 0-043— 0-o8$nm. Mycale placoides has been rather carefully described by Carter in the place quoted, and he has rendered an account of most of the characteristic structural features. On account of the great resemblance between this species and the following one, it will, however, be of importance that a full description is given of both of them. The form of the sponge seems to be somewhat varying, but is always erect; the hitherto known specimens, mentioned and figured by Carter and Topsent, are erect and more or less cylindrical or club-shaped, being somewhat narrowed below. All the specimens before me are more or less damaged, but with regard to the form it may, however, be decided from them that the sponge, besides the mentioned form of which I have some specimens, may also be more or less compressed, or be drawn out into some broad and irregular lobes reaching through the whole length. The specimens mentioned by Carter and Topsent had a height of 6-5 — 9°'". Most of the specimens before me are considerably larger, the club-shaped specimens thus up to a height of 17 The largest specimen consists of some fragments which were stated by the collector, Dr. Morten sen, to have belonged to one specimen. Its form has been somewhat compressed, presumably as a thick leaf. It has been a very large specimen; but the lower part wanting, and, I suppose, to a rather great extent, the height cannot be given, but the breadth above has been ca. 30"", and the thickness 5 The consistency is soft and not elastic, and therefore the sponge, in spite of the thick fibres, is ra1 fragile. The mentioned largest specimen is stated to have been very slimy, when it was taken up in the trawl. The colour (in spirit) is generallv whitish yellow. The surface^ as is well known, ha characteristic appearance being completely furrowed by a large number of sinuous or branching fur- rows that may be arranged in very different ways. The parts between the furrows are finely shaggy from projecting spicules, while the furrows are smooth. The dermal membrane is thin without any particular skeleton; it is supported 1>\ the ends of the fibres, the spicules of which are spread in a penicillate way, and project a little through it, and it is stretched over the furrows of the surface. Pores and oscnla. As has been very well described by Carter, the mentioned furrows in the s irface are pore areas. They may show a very different arrangement, being sinuous and branched in many different ways. They may be placed rather near to, or more far From, each other, aud conse- quently the parts between them may be larger or smallei plates, 01 may be reduced to projecting knobs or rather long keels. Then the furrows may be quite narrow, almost qiiil d, or br> and flat; this latter feature is probably mostly caused by the greater 01 lesser contraction of tl in the place in question. The pores are found in the membrane that is stretched in the furrow, 11 frequently very close-set, so that the membrane resembles a sieve. Of the strings of tissue separating the pores, some are generally thicker principal strings, between which the pores are placed more 01 lesj arranged in series. These strings, which may be distinctly seen by means of a magnifying glass, p Tli'- [ngolf-Expedition VI. 2. 2o PORIFERA. II. in the more narrow areas more or less transversely from one side of the fnrrow to the other. The size • >f the pores is generally 0-035 — o-imm. The thin pore membrane is not directly supported by the skeleton, ami only microsclera are found in it, especially chelae, partly in beautiful rosettes, partly scattered, but sigmata and rhaphides, singly and as trichodragmata. As mentioned by Ridley and Dendy under Esperella murrayi (1. c. 67), a fine longitudinal striation is also fonnd here in the strings of tissue between the pores, which, as supposed by the mentioned authors, is perhaps owing to muscle-like fibres. Frequently 110 pores are seen in the membrane of the furrows, but then it is to be supposed that they are closed. Oscula are found in the upper end of the sponge, and sometimes some way down the sides; they are formed like small cones, of a height of only a few millimetres. The oscular aperture is found at their point, and has a diameter of 1 — 2mm. The wall of the oscular cone has a dense spiculation of needles placed parallel to the longitudinal axis of the cone; these needles are of the same form as those supporting the dermal membrane, that is to say of the smaller form. On the upper part of the sponge, where oscula are especially found, the pore furrows are wanting or are only found to a slight degree. The skeleton is of the dendritic type; from the base fibres issue which anastomose and branch, most frequently more or less irregularly, up through the sponge. The real, single fibres are generally not particularly thick, at most about o-47mm; but especially in the lower part of the sponge several fibres are often united into strings apparently forming a single fibre, and reaching to a considerable thickness, but under the microscope they are seen to be formed of several close-set fibres. Towards the surface the fibres branch copiously, and run as parallel fibres of a thickness of about o-o6mm and with a distance of 0-25 — o-30mm towards the dermal membrane; here the spicules spread in a peni- cillate way and pierce the membrane. Where the pore furrows are found, the fibres pass off to the sides, so that the membrane in the furrow is not supported or pierced by spicules. No transverse fibres are found, but between the fibres and their finer branchings spicules and bundles of spicules are scattered irregularly and more or less densely. In the outer part of the skeleton, at the surface, it becomes more regular by the fact that the ends of the fibres here run parallelly with fixed inter- vals; some transversely placed spicules are here found interwoven between the fibres. These transverse spicules, as well here as deeper in the sponge, are generally of a form differing somewhat from that of the spicules forming the fibres; they belong to the shorter and thicker forms, and are always a little curved. The spicules in the outer end of the fibres, which are spread in a penicillate way, con- sist of styli of a definite kind, smaller than the other styli of the skeleton, as has already been observed by Carter. Spongin is found in the fibres uniting the spicules; but nevertheless the fibres are loose and little capable of resistance; with regard to this fact, however, there is some difference between different individuals. S pic ula: a. Megasclera are styli or slightly marked subtylostyli. They are of two forms, as the spicules that support the dermal membrane spread in a penicillate way, as mentioned, are smaller and of a form somewhat different from that of the skeletal spicules. These spicules supporting the dermal membrane may, for the sake of shortness, be called dermal spicules, although they cannot be said to form any particular dermal skeleton. The skeletal styli are straight, or have a larger or smaller curve nearest to the upper end; this end is rounded and sometimes slightly swollen. The PORIFKRA. II. ,- upper end of the styli are not rarely formed as stated by Bowerbank with regard to .1/ consti and J/, lingua; in this ease a kind of handle is found on the spicule, the upper end being nam. for a shorter or longer way and then passing rather abruptly into the thicker part. This structure of the spicule may be more or less marked, and is frequently almost imperceptible, and it is often quite wanting The feature may, moreover, be different in different individuals, so that it is found more frequently and more marked in one individual than in another. The needle is thickest in the middle, and the tapering end runs into a point rather much varying in length as well in one indivi- dual as in different individuals. The length of the styli varies from 0-447 — 0715"'" and the thickness from cvoio — cvoi6mm; these are the limits within which 1 have found the needle varying in the species, but there may be some difference in different individuals, and in one individual the needles do not generally show so great a variation. The limits most frequently found may he given as to length 0'5 — o-65mm, as to thickness o-oi 1—0-015""". As before mentioned, the transverse spicules occurring out- side of the fibres are oftenest a little shorter and thicker than those forming the fibres, and thev are curved. Finer developmental forms are only seen in small numbers. The dermal spicules are straight; they are of a particular form, their thickest part being found nearest to the pointed end, while thev are evenly tapering towards the rounded end, which is often very slightly expanded. Sometimes at the rounded end they may be of the same handle-like form, as is meutioned in the skeletal spicules. While their size and the length of their point, and by these features to some degree also their form, is rather constant in one individual, they vary not a little in different individuals. It is, however, chiefly only the length of the point which is varying, but this fact again influences the form and the length of the whole spicule. In some individuals the point is quite short or even rounded, and then the thicker part of the spicule is found close to the point; in others the point is even and of a mi length, and in others again very long, up to quite exceedingly long and thin; in the latter the thicker part of the spicule is then found about in the middle. That it is really only the point that is varying length, is also seen by the fact that the longer the point, the longer is the spicule. The length varies altogether in the different individuals from 03 — o^"""; in the separate individuals it is, for instance, 0-3— o^S1""1, 0-35 — 0-42""", 0-42—0-5""", and these lengths are quite corresponding to the smaller or greater length of the point. The thickness, which is also a little varying, as well in the species as in the separate individual, is 0-007—0-01""". '-'• Microsclcra are anisochelse palmatse, sigm and rhaphides in trichodragmata. 1. The anisochelse are of the common Mycale-type; the shaft is slightly curved, the alee of the larger end are broad and diverge towards the middle of the chela, their sides are much refolded. The tooth is rather narrow, and most frequenth somewhat rounded the end; the tuberculum is long and narrow, and there is a rather broad Ealx. Tin the smaller end are broad, and diverge only a little towards the middle of the chela, and their sides are much refolded; the tooth is rather broad, and the end is straightly cut off, the tuberculum is small elliptic. Both alse and tooth here being broad thev leave only a narrow slit between them. While the ake and the tooth of the larger end converge towards the end oi the chela, this is 011I3 to a slight degree the case with those of the smaller end, and consequently this end gets a peculiar, straightly cut off appearance. Both the alae and the tooth in the smaller end of the chela are curved about 1; circular line, so that a transverse section through the chela would here be almost a circle. Thesi r PORIFERA. II. chelae vary very much in size. Their greatest length is 0092™'", but there may be a little difference in different individuals, so that in some they reach at most o"o86mm. The thickness of the shaft is ca. 0-005— o-oo7m,n, and the greatest breadth is ca. 0-030 — 0-03 5""™. This largest form of the chelae may vary a little in form in different individuals, especially the upper end may be a little shorter or longer. From the greatest length the chelae may now vary down to so small a size as o-025mm; at the same time the dimensions of the several parts of the chela are also altered, the ends, especially the larger one, becoming longer in proportion to the free middle part of the shaft. While thus in the large chelae the larger end, the free middle part, and the smaller end are in a mutual proportion about as 2:2:1. these parts are in the smallest chelae about as 2 : 1 : 1. In the series of variations of the chelae the forms which would follow nearest to the largest ones, are of very rare occurrence, so that the chelae would almost seem to fall in two groups, the larger ones only little varying in size, and the smaller ones very varying in size. That such is the fact would also be implied by another thing, viz. that only tlie large chelae occur in rosettes, while the small ones are never seen arranged in that manner. This recalls to some degree the feature in several Desmacella-species, in which only the larger of the two occurring forms of sigmata are developed in bundles, while the smaller form is never arranged in that way. Developmental forms of the chelae are also found, but most frequently only in very small numbers; only in a few individuals they were a little more numerous. As the chelae they are found in all lengths. The youngest developmental form I have seen, is an exceedingly fine staff recurved in both ends, a little more in one end than in the other. During their growth as well the shaft as the recurved parts grow thicker while in the curves the axis remain thin; the alae and the plate of the tooth is by and by developed, by which fact the parts of the axis situated in them disappears or is effaced, while the free middle part of the axis gets its final thickness. The part of the axis situated in the curve itself, on the other hand, is not thickened, but keeps its original thickness, and from this part inward is developed the thin plate, the socalled falx, connecting tooth and shaft. The falx is already developed at an early stage. The chelae are found both throughout the sponge and in the dermal membrane, as well singly as in rosettes; as above mentioned only the large ones are found in rosettes; these rosettes are seen especially often in the pore membrane covering the furrows. The large chelae are also found singly. 2. Sigmata; these are of the common form, and are almost always more or less contort. Their length, which may be somewhat dependent on the degree of contortion, is between 0-017— 0'027mm; the thickness is between ca. o-ooo8 — o-ooi4mm. 3. Rhaphides; these are sometimes seen singly, but most frequently in bundles, trichodragmata; the length of the individual rhaphides varies from 0-043 — o-o85'nm; such is the variation in the species, but in the single individuals it is not so great, for instance 0-047— o-o67mni aim 0-064— o-o85mm. ^n individuals with the shortest styli also the shortest rhaphides are found. The thickness is about o-ooimm. The thickness of the bundles is 0-013 i8",m. Sigmata and rhaphides occur both in the dermal membrane and throughout the sponge, especially rhaphides in dragmata are of frequent occurrence iii all parts of the tissue. Locality: Station 1, 62 : 30' Lat. N., 8° 21' Dong. W., depth 132 fathoms; station 7, 630 13' Dat. N., [5 41' Long. W., depth 600 fathoms; station 55, 630 33' Lat. N., 150 02' Long. W., depth 316 fathoms. Further it has been taken on 65° 39' Lat N., 28° 25' Long. W., depth 553 fathoms (the East-Greenland Expedition 1891—92); 64° 15' Lat. N., n° 15' Long. W., depth 192 fathoms (Wandel); the bay of Skage- P0R1FERA. II. 2( strand in Iceland (Wandel); at the north end of Nolso, depth ca. coo fathoms (Th. Mortensen); 62 50' L,at. N., 1 ° 56' Long. E., depth 275 fathoms (Ad. Jensen, the cruise of the Michael Sars 19021; altogether ca. nine more or less damaged specimens. The localities are situated in the Denmark vStrait, off the northern coast of Iceland, between Iceland and the Faroe Islands, off the east coasl of the I'. Islands, and to the north east of the Shetland Islands. Geogr. distr. Besides on the localities mentioned above the species has been taken abou miles to the north north west of the Shetland Islands, depth 345 fathoms (the Porcupine . Carter); further it has been taken farther south, off Xew Foundland, depth 073 fathoms (Topsent). 2. M. lingua Bow. PI. IX, Fig. 6 a- f. 1S66. Hymeniacidon lingua Bowerbauk, Mon. of Brit. Sponges, II, 1S7, 24. 1866. Dcsmacidon constrictus Bowerbank, ibid., II, 350, 4. 1874. Raphiodcsma lingua Bowerbauk. ibid., Ill, 119, PL XI/VII, fig- 8, 237, PI. LXXVII, figs. 1 6. 1874. Desmacidon constrictus Bowerbank, ibid., Ill, 181, PL LXXI, figs. 3 — 10. 1880. Espcria lingua Yosmaer, Xotes from the Leyden Museum, II, 146, 24. 1886. Espcrella Vosmaeri Levinsen, Dijmphna-Togtets zool.-bot. Udbytte, 20, 15, Tab. XXX, Fig. 11 — 14. 1887. Espcria lingua Fristedt, Vega-Exp. vetensk. Iakttag. IV, 449. 1892. Espcrella lingua Topsent, Resultats des Campagn. scient. du Prince de Monaco, Fasc. II. 88. 1896. Lambe, Transact, of the Roy. Soc. of Canada, ser. 2, II, sect. IV, 186, PI. I, figs. 6, 6 a— f. 1904. Espcrella lingua Topsent, 1. c, Fasc. XXV, 200. Erect and somewhat tongue-shaped, or more irregular. The dermal membrane thin. supp* by projecting spicules, the surface consequently finely shaggy; it is provided with sinuous or branched pore-furrows. Oscula in the upper half of the sponge, on die top of small oscular cones. The she,' consists of polyspicular fibres branching up tlirougli the sponge The spicules piercing the dermal membrane of the same size as the other spicules of the skeleton. Spicula: Mcgasclcra styli or slightly marked subtylostyli, sometimes with the upper end formed like a handle, o-jj—r/y""; microsclera of three forms, anisochelce palmahr n', and the smallest specimen, which is more roundish, hut also compressed, is of a height of a little more than .: ". The consistency is rather soft, and the sponge is easily torn. The colour (in spirit) is most frequently whitish yellow 01 gray. The surface resembles that of tin preceding species, and furrows of the same kind arranged in different ways are found. These furrows are also here smooth, while the other parts are a li PORIFERA. II. more shaggy than in the preceding species. The dermal membrane is thin and has no particular skeleton, but is supported by the ends of the fibres projecting through it, and by the transverse spicules connecting the fibres. Pores and oscula. As mentioned above we find in this sponge as in the preceding one furrows in the surface that may present a very varying arrangement. These fur- rows are also here pore areas, the dermal membrane being stretched over them and provided with pores quite as in the preceding species. The pores are placed very close, and most frequently more or less arranged in transverse series separated by thicker principal strings. Also here a fine, muscle-like longitudinal striation is found in the strings of the tissue between the pores, which striation was seen still more distinctly than in the preceding species. The pores are round or oval, and in the examined pore area they had an average diameter of about 0-015 — o-02mm. The pore furrows in the specimens in hand are smaller and are present in smaller numbers than in the preceding species; in one of the specimens they are all quite closed, and then they appear as quite narrow keels arranged in a somewhat netlike manner. Pores seem also to be found outside the pore furrows; but it is diffi- cult to decide this fact by material which is not fresh or especially well preserved. Ridley and Dendy state it to be found in E. murrayi. Oscula are small, more or less steep cones of a height of 2 — jrnm The oscular aperture is found in the end of these cones. The wall of the cones is provided with a very dense spiculation of spicules parallel to the longitudinal axis of the cone, and their ends project round the aperture. In the larger specimens oscula are found in rather large numbers and are restricted to the upper half of the sponge. The skeleton is of a dendritic type, and is constructed as in the preceding species. It consists of fibres branching from the base up through the sponge and anastomosing. Also here the single fibres are closely united into thicker ones that are apparently single ones, and these thicker fibres are often not cylindrical. The single fibres have been measured to a thickness of at most o-65mra. Towards the surface the skeleton sends forth finer branches running parallelly, and supporting and piercing the dermal membrane; between these fibres some transverse spicules are found. The ends of the fibres which appear as bundles of spicules, are in this species formed of spicules of the same kind as the other spicules of the fibres, so that no specially formed dermal spicules are found. The transverse spi- cules found between the fibres that are parallel and run towards the surface, are also in this species of a form somewhat different from the form of those forming the fibres, being shorter, thicker, and curved. A slight amount of spongiu unites the spicules of the fibres, but is only little conspicuous. Sf>ienla: The spiculation of this species is upon the whole like that of the preceding one. a. Megasclera are styli, or may have a slight tendency towards subtylostyli. Most of them are straight, but some are slightly curved ; they are fusiform, tapering towards both ends, which holds good especi- ally with regard to the shorter and thicker ones. The upper end is rounded and sometimes quite slightly swollen; the handle-like form of this end mentioned under the preceding species, is also some- times found in the present one, and also here developed to very different degrees. The other end of the needles runs into a point, which may, especially in different individuals, be very varying in length, from being quite rounded to a long, fine point. The length of the needles is rather varying, as well in one individual as in different individuals. As mentioned the transverse spicules between the fibres running towards the surface are shorter and thicker than the other spicules, a distinct limit, however, PORIFERA. II. j] cannot be drawn; these spicules do not vary much in length in the different individuals, and the smallest length of the needles, therefore, is rather constant. The greatest length of the needles, on the other hand, varies much in different individuals, and this length is dependent on the length oi the point, so that the longer and finer the point is, the longer is the needle. The boundaries of the length of the styli upon the whole in the species are 0-53— ri5m'", but when given E01 p te indivi- duals, the length of the point being also taken into consideration, we get for instam 0-804""" the point more or less rounded; o-6o— 0'95ram the point short; 0-65 — imm the point rather long; cro; ri5mm the point very long. The thickness of the needles is somewhat varying, and the longest ones are far from being the thickest ones, the mentioned transverse spicules being both the shortest and the thickest; the thickness is between ca. o-oi3mm and o-02'nm. Some difference may be found in diffe- rent individuals, especially with regard to the greatest thickness, which sometimes does not exi o-oi8mm. Finer developmental forms are seen, but only singly, b. Microsclera : these are ani palmatEe, sigmata, and rhaphides in trichodragmata. 1. The anisochelae are of the common Mycale- type and constructed in almost quite the same way as the chelae of the preceding species, the only difference being that the tooth of the upper end is broader. The greatest length of the chelae is 0'092""", but there may be some difference in different individuals. The thickness of the .shaft is ca. o-oo8mm, and the greatest breadth is 0-028 — o-04mm. From the greatest length the chelae vary in size down to o-028""n, and at the same time the proportionate dimensions of the different parts are altered in a similar way as in the preceding species. The chela; are not rarely a little twisted. Also in the present species a break is found between the large chela; and the largest of the smaller ones, and also here only the large chelae are found in rosettes. A few developmental forms were found quite corre- sponding to those in placoidts. 2. Sigmata of the common form, often somewhat irregular and n or less contort; their length, which is much dependent on the curve, is between 0-021 and 0-032""", and the thickness varies from o-ooio— o'OOi5mm. 3. Trichodragmata; the single rhaphides are ol a length of 0-042— o-oyS'"'", most frequently about midway between the two sizes; the thickness is 0-0008— o-ooi4mm. The rhaphides are almost only seen in trichodragmata. of a thickness of 0 o-oi4m'". The microsclera are numerous throughout the sponge, sigmata are of especially frequent occurrence in the dermal membrane. The large chelce occur in many places, in rosettes in enormous numbers. Remarks: In the above mentioned largest specimen taken at Upernivik, there are found lure and there in the sponge, but in verv small numbers, some peculiar spicules that may be designated as tylostrongyla, and whose form may be seen in the annexed figure [fig. 1), which represents three of these spicules and the end of a fourth, and shows different forms of the end-swelling. One end is rounded, while the other is swollen to a more or less pyriforin expansion. These spicules always occur in a particular way being only found in the projecting bundles of spicules, always only on. a few spicules in the same bundle, and only here and there, so that many of the ing bundles may be examined without any being found. In the bundle they are always placed with the swollen end outward, so that it is seen between the points of the othei projecting spicules. It is easilj that these spicules, with the exception of the swelling, are in all other respects of quite tlu same PORIFERA. II. form as the normal spicules of the species; the not-swollen end is rounded or quite slightly dilated, in other words it has quite the same form as in the normal spicules, and consequently it is the point of the spicule that is transformed. Also its position agrees with this view, it having, like the other jecting spicules, the head-end turned inward. This spicule, which occurs here so scattered and in small numbers, must be regarded as an abnormal form, and in the bundles transitional forms are also found with slightly swollen or only rounded outer end. That the spicule should be of extraneous origin is quite out of the question, as well on account of its form, as its always occurring in the same way. — It would seem that projecting dermal spicules upon the whole are somewhat liable to be influenced with regard to the form, especially of the outer end, of which among others Alycale placoidcs furnishes an instance by its dermal spicules that vary so characteristically in different indi- viduals. The occurrence of this spicule, however, is not without interest, as it is of a quite similar form and occurrence as the dermal spicules in Rhapliidothcca Marsliall-Hallii Saville-Kent (Ann. Mag. Nat. Hist 4. Ser. VI, 219, PI. XV, figs. 1 — 7) from the coast of Spain, and Rhaphidotheca affinis Carter (Journ. of the Row Micr. Soc. II, 497, PI. XVII, figs. 1 and 3) from a locality between Scot- land and the Faroe Islands, which latter species is probably identical with the former J). This species has the common J/yctf/^-spieulatioii quite as in lingua, but in all, or almost all, the spicules of the pro- jecting bundles the outer end is swollen in a pear-shaped manner. (Saville-Kent says expressly that a few pointed spicules are found in the bundles.) In this species the feature has thus no doubt become normal for all or almost all projecting spicules. The opinions advanced by Carter (Ann. Mag. Nat. Hist. 5, I, 170, Journ. of the Roy. Micr. Soc. 1. c, and Ann. Mag. Nat. Hist. 5, IX, 299) that these spicules should be foreign and embodied by the sponge, and that their form should have been altered by the sponge after the em- bodiment, with reference to which latter fact he, in the place last quoted, even says: has been shown to be adventitious or appropriated, Inning first belonged to another sponge», are devoid of all foundation, and it is a peculiar thing that Carter has not been able to see, from their form and way of occurrence, that they belonged to the sponge. The whole question debated in the places quoted, whether needles may occur turning the pointed end inward in the sponge and projecting with the head-end, is likewise of no consequence, as it is a fact that the mentioned spicules turn their head-end inward in the sponge. Fig. 1. x 165. ') Vosniaer 1. Votes from the Leyden Museum, II, 141, 8) refers, with a query, Rhaphidotheca Marshall-Hal/ii, as a sy- nonym to Esperella nodosa O. S. In the description of Schmidt, however, there is no base at all for this referring. PORIFERA. II. ,, - Saville Kent's species, however, is not the onl) one with such spicules, and the transformation of the ends of the projecting needles seems in some instances to go still farther. Topsent (Bull, de la Soc. de Fr. XXI, 1896, 149, fig. 2 a— f) has thus established a new genus, Gomphostegia1) with the species loricata that is also a Mycaline with the typical Myc«&?-spiculation, but with projecting spicules the outer ends of which are widened to a slightly crenelated disc and thus form a mail. In these needles, which Topsent calls Exotyles», the head-end, which is turned inward in the sponge, is formed in quite the same way as in the other styli in the sponge. Thus there seems t<> In- a gradual development in the formation of the ends of the projecting dermal spicules from forms where it only occurs as an abnormal fact, through such where it has become a normal feature, to forms 111 which it has been developed to an exceedingly high degree. Locality: Station 3, 63° 35' Lat. N., 700 24' Long. W., depth 272 fathoms; station 54, 63 08' Lat N., i5°4o' Long. \V., depth 691 fathoms; further it has been taken at Upernivik (the Reverend .Mr. Sorcn- sen); J2: 53' Lat. X., 20° 36' Long. W., depth 96 fathoms (the East-Greenland Expedition 1891— 921; 63 15' Lat. X., 90 35' Long. W., depth 270 fathoms (Wandel); 62 30' Lat. X., 1 56' Long. E., depth 275 fathoms (Ad. Jensen, the cruise of the Michael Sars , 1902). Altogether six specimens, most of which damaj The localities are situated in the Davis Strait, off East-Greenland, between Iceland and the Faroe Islands, and to the north east of the Shetland Islands. Geogr. distr. The species has further been taken off the southern Greenland, 61 15' Lat. X., 49c 11' Long. W., depth 70 fathoms, and 59c 33' Lat. X., 43 25' Long. VY., depth 120 fathoms (Fristedt); the northern coast of Scotland and the Shetland Islands (Rowerbank); the Kara Sea, depth 65 fathoms (Levinsen); the eastern coast of Canada, depths 75 and 80 fathoms (Lambe); off the north-west coast of Spain, depths 71, 133, and 160 fathoms, off New Foundland, depths 673 and 82 fathoms, and at the Azores, depths 69 and 185 fathoms (Topsent). Thus the species is in the mentioned seas distributed about from 73° to 400 Lat. N., with a bathymetrical distribution from 65 69] fathoms. Remarks on the species Mycale placoides mid lingua. These two species are exceedingly closeh related to each other. The external form, the pore furrows, the structure of the .skeleton, and. partly, the spiculation show great conformity. Among the distinguishing characters the most important one is the presence of particular dermal spicules (the spicules that arc spread in .1 penicillate wa\ and carry the dermal membrane) in placoides, while in lingua these spicules are oi the same form and size as the other spicules fit the skeleton. It is especially this character that is of value as a sure distinctive mark between the two species. Further the tooth in the larger end of the chela is in lingua than in placoides, as is seen from PI. XI, fig. 5 e compared with fig. 6 c. Then the styli are upon the whole longer and thicker in lingua than in placoides, and finally the sigmata are also most frequently larger in lingua than in placoides. If I have determined the two species as placoides and lingua. 1 must remark thai I M In the- work by Topsenl 1 [904 (p 102, PI. XIV, Kg. 15) quoted in the list of s\n..nynis he has acknowledged that Gotnphostegia is synonymous with Rhaphidothcca. I 1 - in;. .11 I ;xpedil ion. VI , I rORIFERA. II. expressly says of placoides that the spicules projecting through the dermal membrane are smaller than the others, while his other description agrees very well with the specimens before me. I have then determined the other species as lingua, but from the description of Bowerbank it is not to be seen with certainty, whether he has possibly had placoides or perhaps both species before him. Topsent, I.e. 1892, enumerates both lingua and placoides, but gives no description, so that it cannot be seen, which characters he takes to be the distinguishing ones. The peculiar handle-like formation of the upper end of the styli cannot be used, as this formation, as is seen from the preceding descriptions, is found in both species, and may occur very varying with regard to its frequency and degree of marking. Therefore I also follow Topsent in regarding Bowerbank's lingua and constricta as one species. When Topsent in the place quoted mentions that he has seen specimens of lingua with pore furrows, and others without such and with a uniform, slightly shaggy surface, I must suppose that in the latter the pore furrows have been closed, the slight keels then found being often only very little conspicuous. I have omitted to quote Espcria constricta Vosmaer (Niederl. Arch, fur Zool. Suppl. Band I, 1881—82, 45), and Espcria lingua Vosmaer (Bejdr. tot de Dierk. i2te Afl. 3die Gedeelte, 1885, 30), as it is impossible to decide, which of the two species mentioned here the author has had before him. The figures in the former place, PI. Ill, fig. 99, and in the latter place, PI. V, fig. 73, might both look like dermal spicules of M. placoides. but nothing can be decided with certainty. Neither have I quoted Espcria constricta Mareuzeller (Die oesterreich. Polarst. Jan Mayen, III, 10), the author's good and rather copious account of the variation of the spicules would seem to indicate that he has had both species before him. Thus with regard to the geographical distribution we can, from these facts, only infer that one or the other, or both species occur in the Barent Sea between 720 and 750 Lat. N., and between 150 and 360 Long. E., on depths between 128 and 175 fathoms, as well as at Jan Mayen on depths from ca. 48 — 200 fathoms. The E. Vosmacri established by Levin sen 1. c. I have, by an examination of the type specimen, found to be identical with M. lingua; Levinsen does not mention rhaphides, which, however, are present. The E. murrayi established by Ridley and Dendy Challeng. Report, XX, 67, PL XIII, figs. 11, 13, 14, 16, 17, 18; PI. XIV, figs. 1, ia) is by Topsent 1. c. referred to E. placoides, and by Eambe 1. c. to E. lingua. If the chela figured by Ridley and Dendy fig. 17 is correct with regard to the tooth of its smaller end, a specific identity with placoides or lingua is out of the question, neither does the description of the dermal skeleton or the length o-c>53mm given for sigmata agree with any of the two species. The E. lingua var. arctica established by Fri- stedt (Vega Exp. vetensk. Iakttag. IV, 449, PI. 25, figs. 20—24, PI. 29, fig. 18) cannot be E. lingua, only on account of the measures given for the spicules, but must be another, independent species. 3. M. ovulum O. Schmidt. PL I, Figs. 6-8, PL X, Fig. 1 a— e. 1870. Chali)iula ovulum O. Schmidt, Grundziige einer Spougienfauna des atlaut. Gebiet, 38, Taf.V, Fig. 1 x). 1873. O. Schmidt, Jahresber. d. C0111111. zur wissensch. Unters. deutsch. Meere in Kiel fiir 1871, 99. ') In the explanation of the plate the name, presumably by a misprint, is Chalimtla ovum. PORIFERA. II. .- 3.-) 1875. Esperia lanugo O.Schmidt, ibid, fur [872—73, ci8. 1879. Esperia stolonifera Merejkowsky, Mem. de I'Acad. imp. des sc. de St. Petersb., Ser. 7, XXVI, Nr. ; 22, PL I, figs. 13, 14, PI. Ill, figs. 4, 5, 12— 19 and 23 29. 1891. Chalinula ovulum Grentzenberg, Spongienfauna der Ostsee, Inaug. Dissert, Kiel [891, 27. Fig. n 1891. Esperella lanugo Grentzenberg, ibid. 34, Fig. 22 — 26. 1893. Esperella ovulum Levinsen, Det vidensk. Udbytte af Kanonbaaden Ilauch s Togter, 423, Tab. I, Fig. 40 — 41. 1903. Esperella lanugo Arnesen, Bergens Mus. Aarb. [903, Nr. 1, 10, Taf. I, Fig. 6. 1903. Mycale lanugo Thiele, Arch. Kir Naturgesch. 1903, 381, Taf. XXI, Fig. 11. Egg-shaped, or the larger specimens lengthened or quite irregular. The dermal membrane thin pureed by the projecting spicula-bundles, and the surfaee therefore finely shaggy, in the regular. < shaped specimens one single osculum, in the irregular ones several scattered oscula. The skeleton a rather regular network of polysplenia? ; primary fibres and singly placed transverse spicules. Spicula: Megasclcra rather short, curved styli cri66 — this fact, however, some difference may occur in different individuals, so that the fibres may contain both fewer and more spicules. The distance between the fibres is about oi2mm, and the average thick- ness of the fibres may be given as o-035mm. Coherent transverse fibres are not formed, but between the primary fibres transverse spicules are found, most frequently singly, and without any regularity. Some- times a tendency towards a more regular net of meshes may appear towards the surface. In many of the individuals the primary fibres do not pass straight towards the surface, but show a tendency to turn upward towards the upturned end of the sponge, so that the fibres in the egg-shaped roundgrowing speci- mens may radiate to all sides, but at the same time turn upward, so that it may be seen, especially in a longitudinal section, which end of the sponge has been turned up, and which has been turned down- wards. Spongin is found in the fibres, but only to a small amount, and it is exeedingly white and clear. Spicnla: a. Megasclera are styli; they are more or less, often rather much, curved, and the curve is almost always nearest to the upper end. The other end passes evenly into a point of middle length, the outer end of which is most frequently somewhat shorter pointed. The needles are thickest about the middle, also tapering somewhat towards the rounded end, and being thus a little fusiform. The length is between cri66mm and o-3imm, but in many individuals the needles do not vary so much; thus individuals are found in which they reach no greater length than o,23mm. Also the thickness is somewhat varying, from c/006— o-n'"m, and also in this respect some difference is found in different in- dividuals. The thickest spicules are not always the longest ones. Besides the fully developed forms developmental forms of every degree of thickness occur, and in some individuals these forms are found in large numbers scattered in the tissue outside of the skeleton formed by the fibres; they were found down to an exceeding fineness, less than o-ooimm, and developmental forms of this thickness were measured to a length of o-i5",ra. The developmental forms, in contradistinction to the fully developed ones, are long pointed. The individuals copiously provided with developmental forms of the styli seemed upon the whole to be in a state of lively formation of spicules, developmental forms of the chelae being also seen abundantly, b. Microsclera are only of one kind, anisochelse palmata;. They are characteristic by the smaller end being comparatively large, larger than is common in the Mycale- anisocheke. Their shaft is straight, and they are otherwise of the common type; the alse of both ends are highly folded round on the side; the tooth of the larger end is narrower than the alse and rounded at the end; the tooth of the smaller end is of the same breadth as the alse, and it is some- what pointed, which seems to be owing to the fact that the axis continues quite to the point of the tooth; the ake of this end pass to the shaft in such a way as to make their upper or free edge parallel to the upper edge of the tooth. In each end an oblong tuberculum is found. The chelae vary not a little in size and also in form; thus they may be more broad or more narrow, and the comparative sizes of the ends may be somewhat different; in a few cases there is almost no difference between the two ends, so that the chelse approaches an isoehela in form; generally, however, they are not to be confounded with isocheke, as it is most frequently only the teeth that are of equal or about equal size, while the aloe of one end continue to be smaller than those of the other, as shown in I'ORIFERA. II. 0/ fig. i d, PI. X. The smaller the chela, the smaller is the free middle part of the shaft in proportion to the ends, which are, accordingly, comparatively longer than in the larger chelae. The length of the chelae varies between o-o20— 0-045™'", the breadth between o-oo; o-oi5mm, and the thickness of the shaft between o-ooi — o-oo2mm. In several of the individuals developmental forms are found abundantly, corre- sponding to all sizes of the chelae; the youngest forms are so fine as to be observed only with diffi- culty, of a thickness of ca. o-ooo5mm. These fine forms consist only of the axis, which is already of full length. From these youngest forms and to the fully developed chela all transitional forms are found. Of the chelae the small ones are present in by far the largest number, while the large ones are 11 scarce, and do not appear to be found in all individuals, some being found, in which the greatest observed length of the chela is ca. cro28mm. The chelae are found throughout the sponge; the larg may occur in rosettes, but this fact has only been observed in very few eases; also Merejkowsky mentions rosettes. Remarks; When Schmidt, in 1870, established this species he referred it to the genus Cha- linula, overlooking' the chelse, and in 1875 he made the same mistake. Also Grentzenberg 1. c. must have failed to see the cheke, there being no reason to doubt that it has really been the present species he has had before him. Levinsen was the first who, in 1893, when examining the type specimen of Schmidt, which is found in our museum, discovered the chela;, and referred the species to the proper genus. In 1875 .Schmidt 1. c. established a species Mycalc (Esperia) lanugo; the de- scription, as is generally the case, is exceedingly brief, and no figures are given. It is, however, said of the chelae that they are distinguished by the smaller end being larger than is else the ease in Esperella, and that in a few cheke both ends are equal, and just this fact is a ver\ characteristic mark of M. ovuhtni. The terms used of the exterior, correspond also very well, it being said that it is roundish von weicher, flockiger Beschaffenheit , which latter character Schmidt has even expressed in the name. Now it is a fact that specimens of ovulutn sometimes, especially when of a whitish colour, may have a peculiar, woolly appearance, about like a little lump of wadding. In 1 Grentzenberg 1. c. enumerates E. lanugo, and gives figures of it, and to judge both from the habitus figure and the rather bad figure of the chela, as well as from the whole description, there can be no doubt that the species is identical with ovulum1). This, again, corroborates the referring of Schmidt's lanugo to ovulum; for, as far as can be seen, Grentzenberg lias of this species only had the material of .Schmidt. Thus we find the peculiarity that as well Schmidt as Grentzenberg has, both of them and each in a work of his own, enumerated one species as two different ones, partly as Chalinula ovulum, partly as Esperella lanugo; this peculiarity, however, ma; so fai be understood, the reason is that in one case the chela' have been overlooked. Under K lanugo Grentzenberg mentions that besides the common skeleton it possesses ein aus Fasern gebildetes Geriist, dass Schmidt nichl erwahnt . He describes further that in a transvi section is seen about in tile middle of the Sponge a circular fibre, inside of which run four or five radiate ones coalescing in the middle. He figures this structure in fig. 24. The author thinks til fibres to lie spongin fibres, and he mentions some cells which are said to form those fibres in a ') I have later had the opportunity of examining a cimen ol 1/ . ..... which proved the species t<> be identical with ovulum. 3« PORIFKRA. II. peculiar way. Now it is not said whether spicules are found in these fibres, but they are figured without such. A spongin skeleton of a so peculiar kind, not seen to be in any way connected with the other skeleton, would be quite unique. By a look at fig. 24 it is obvious that the question cannot lie of spongin fibres; through the middle of each of the radiate fibres runs a line which is said to mark the coalescing, but in reality shows that the figured things are evidently vegetable cells. As before mentioned the sponge frequently grows round Algae, which is also the case with the figure of the exterior given by Grentzenberg, and then the Alga runs about through the middle of the sponge; the author also says that the peculiar circular fibre is found nearly in the middle of the sponge. To be sure there can be no doubt that by the cutting out of the transverse section of the sponge the incrusted Alga — it looks like a Polysiphonia - - has been cut through, and it is this transverse section which has been interpreted as the peculiar circular fibre with the radiate fibres inside. The Espcria stolonifera established by Merejkowsky 1. c. is by Levin sen referred to ovulum as a synonym, and to judge from the description and figures they are surely identical. I have, however, in no case observed the net of thin off-shoots mentioned by Merejkowsky for some of his specimens. Locality: Of this species we have a great number of specimens, all from Greenland, Iceland, and the Faroe Islands. Greenland, without any designation of locality (Schmidt's type specimen); Egedes- minde (M. Porsild); the Ingolf, off Bredebugt, on station 87, depth no fathoms; Rostin in Bredebugt ill. Jonsson); Onuudarfjord, depth 10 fathoms (the author); to the east of Bakkefjord, depth ca. 70 fathoms (Hallas); Skulavig in Seydisfjord, depths 6 fathoms and 30 fathoms; Berufjord, depth 10 fathoms (A. C. Johansen); the Faroe Islands (Miiller); at the north point of Xolso, depth ca. 100 fathoms, 6 miles N. to W. of Kalso, depth 60 fathoms, Saudsbugt (Th. Mortensen). Gcogr. disfr. Besides 011 the above localities the species has been taken in the Cattegat between Samso and Sealaud (Leviusen 1. a); in Great Belt, depth 24 fathoms, and in the Baltic at Kiel, depth 3—6 fathoms, Darserort, depth i5I/2 fathoms, Stoller bank, depth 3 — 5 fathoms (Schmidt, 1873), further at Bergen and Espevser (Arnesen), finally in the White Sea (Merejkowsky). Note. Three of the Afycatc-species mentioned in the literature, are with rather great pro- bability to be referred to the present species; I do not, however, venture to decide this question with certainty, or to make any change of names on that account. The first of these species is M. (Isodictya) lobata Bow. (Mon. Brit. Spong. II, 326, III, 148, PL LVIII, figs. 19 — 22); Bowerbauk, to be sure, men- tions bihamates , which are not figured; but these needles might very well be developmental forms of the chelce, and such a fact might also be implied by the observation that they are &exter-umbouates . The second species is M. (Isodictya) Clarkci Bow. (1. c. II, 330, III, 142, PI. LVI, figs, n — 15); the figure of the exterior of this species, which grows on Hydroids, is quite similar to longish specimens of M. ovu- Iidii. Topsent, in his list (Rev. biol. du Nord de la Fr. VII, 15 and 20) has taken this species to be an Esperiopsh, and has referred it as a synonym to E. fucorum Johnst. Bowerbank, however, calls the chela iuequi-anchorate , and the figure also shows an anisochela, but, to be sure, an anisochela in which there is only little difference between the two ends, such as occur in M. ovulum. The third species is the E. modesta established by Lam be (Transact, of Roy. Soc. of Canada XII, 1894, Sect. 4, PORIFERA. II. ,q nS, PI. Ill, figs, i, ia-d; ibid. Ser. 2, II, 1896, Sect. |, [88, figs. 7, j a— d)1); Lambe mentions two kinds of styli, rather thick ones with short point, and thinner ones with long evenly tapering point, but the latter I take to be developmental forms, these having always a longer point than tin- full-. developed ones. 4. M. thaumatochela n. sp. PI. X, Fig. 2 a— g. 1897. Esperella intermedia Vanhoffen (non Schmidt), Gronland Exp. der Gesellsch. fur Erdkunde zu Berlin, II, 1, 248. Incrusting. The surface shaggy from projecting bit miles of spicules; the dermal membrane thin. The skeleton a tolerably regular network of polysplenia r fibres. S pie n la: Megasclera styli irjj — o-^8mm; microsclcra <>f two forms, aiitsochel/r palmata- 0-04} — cru(>""". anisoehehe of a very peculiar structure 0'0i2—0'0i7""". Of this sponge we have only one small specimen growing on a fragment of a shell of Pcctcn islandicus, and a small, inconsiderable, loose fragment. As to the exterior the sponge is very insigni- ficant, and all the interest attaches to the spiculation. The specimen is formed as a very thin incru- station, and its greatest extent is I5mra; but it looks, however, as if the whole specimen is not found on the fragment of the shell. The thickness is at most imm. The colour (in spirit) is light grayish-brown The surface is shaggy from projecting bundles of spicules. There is a thin dermal membrane, without spicules as far as I am able to see. In the dermal membrane circular openings are found, of a dia- meter of 0-047 — °'35mm °f which I take the greater ones to be oscula, and the smaller ones pot The skeleton consists of polyspicular fibres; as far as I have been aide to examine the material, it is formed of fibres running from the base to the surface and projecting through the dermal mem- brane, and of other fibres perpendicular upon the former ones; it seems to lie rather regular. In the nodes a slight amount of spongin is seen. Spicula: a. Megasclera are styli, evenly and most frequently slightly, sometimes a little irregularly curved. They have an even point of middle length, which is often somewhat shorter pointed at the outer end. The size of the styli is rather constant, the length is between 035 and o^S™"", and the thickness is 0-007 — 0-0115'"'". b. Microsclcra. These are of two kinds, anisoehehe palmaUe. ami some small, peculiarly shaped bodies which may also lie characterized as anisochelae. 1. The palmate anisochelse are of a fine regular form and chiefly of the common type. The alse of the larger 1 which are much refolded on the side, diverge downward with their lateral edges, and then they curve somewhat upward with a round bend going in to the shaft; the tooth is somewhat narrowei than the alte, elliptical, but broadest below and rounded, sometimes with a small pointing. The tooth and alse of the lower end are of about equal breadth ; in the middle of the distal edge of the tooth is generally found a pointing owing to the axis continuing quite to the end, and on eithei side of the pointing is found a little notch, so that the tooth is tridentate. In each end there is a longish tuberculum. The size of these chelae is rather constant; the length varies from <■ 6mmbeingmos1 frequently about ') Latnbe, in both places, writes sp. nov., and lias no reference in the latter place; Inn as tin- descriptions are almost equal, I suppose it to be his opinion that the species is tin.- same. Otherwise Solnui.lt lias already in 1S6 adriat Meeri established an /;'. modesta, so thai the name of Lambe's species, Li all events, must be changed. 40 PORIFERA. II. o-o57mm, the greatest breadth is 0-020—0-02 2ram, and the thickness of the shaft is o-oo2'nm. These chelre are frequently found in rosettes. Quite single chela; of smaller size are found, down to 003'11'". 2. The other silicious body found in the sponge is of a peculiar shape, and on account of its smallness and intricate structure it is difficult to get a clear view of it. Its form may be reduced to the aniso- chelate type. Below it consists apparently of a jar- or slipper-like part and above of four alse issuing from the upper end, which alse on four sides extend down over the slipper-like part. The lower part looks somewhat differently, according as the body is seen from one or the other side, and by a preli- minary examination only two of the four alse are seen, one on either side. By a more thorough examination under sufficiently high magnifying powers it is seen that, when the chela is in a certain position, an axis runs along one side, below turning upward to about the middle of the chela; when the chela is placed in such a way as to turn the axis behind, i. e. away from the beholder, the form of the lower part is all but slipper-like; the exact form of this part is only to be seen with difficult}-, but it appears to consist, as usual, of lateral alse issuing from the axis, and of a broad tooth before. Both the alas and the tooth are on the sides folded towards each other, the interstice between them I have not been able to see with certainty, but it is about as shown on PI. X, fig. 2 c. On either side the axis of the chela is in its upper part provided with rather narrow alse separating from the axis about in the middle, and continuing downwards as a single pointed elliptical tooth. Further a free, pointed elliptical ala is found on either side with the flat sides turned laterally, and in the front is found a tooth of the same form. These structures are placed at equal distances from each other, and form the four apparently uniform alse, which pass from above downwards to about three fourths of the length of the chela. The two lateral ala; together with the alse of the dorsal side may be regarded as corresponding to the alse of the axis of a common chela. That the lateral alse are not teeth may be seen from the fact that above they are provided with an uusymmetrical, translucent part, while in the tooth there is a symmetrical tuberculum; they are likewise above and behind connected with the ala of the dorsal side. The ala; as well as the tooth are best seen when turned to the side so as to be seen from the edge, whereas, when turned towards the beholder, they are only to be seen with much difficulty, on account of their fineness and transparency. A good view of the mutual position of the parts ma}- be got, when the chela is seen from the end in such a way, that the lower end is turned directly towards the beholder, who will then see an optical transverse section as fig. 2 f, PI. X, where the tooth, the two lateral alse, and the axis are seen at right angles to each other, and in the middle the lower part in connection with the axis and its alse. These chelse are very small, their length varying from 0-012 — o-oi7n,n', and the breadth being 0-007 — ooo8m,D. Both the large palmate chelse and the small peculiar ones occur abundantly. This species so peculiar and characteristic by its spiculation has by Vanhoffen 1. c. been determined as E. intermedia O. S. As I have had preparations of the specimens of Vanhoffen, I have been able to decide with certainty thas it is the present species he speaks of. Vanhoffen has, strange to tell, made a mistake with regard to the megascleres, and calls them ; beiderseits zugespitzte , whereas the are distinct styli. Schmidt says of his Espcria intermedia that it has unspitzige Xadeln , which I take to be a misprint for , and further his species is provided with two different PORIFERA. II. sorts of chelae, so that an identification with this species, is, for main reasons, excluded. Vanhoffen lias further overlooked the peculiar small chelae1). Locality: The whole specimen has been taken by the Ingolf-Expedition at Holstensborg at a depth of 30 fathoms, and the loose fragment has been taken off Cape Dalton, East-Greenland, depth 9 — 11 fathoms (the Amdrup-Expedition 1900). Geogr. distr. Vanhoffen has the species from West-Greenland, Karajak-Fjord, and mentions that it occurs as incrustations on worm tubes and Brvozoa. 5. M. titubans ( >. Schmidt. PI. X, Fig. 3 a.— h. [870. Desmacidon titubans O. Schmidt, Grnndziige einer Spongienf. des atlant. Gebiet 5s. Taf. V, Fig. 18 a — c. 1882. Desmacidon titubans Carter, Ann. Mag. Nat. Hist. Ser. 5, IX, 298, PI. XII, fig. 24 a— h. Form? The skeleton an irregular network consisting for the greater part oj polyspicular / Spongin wanting. Spicula: Mcgasclera styli oj tzuo forms, larger ones o-jp o'p""", smaller om oyo""": microsclera oj two forms , anisochcla> oj a peculiar, wry form 0-024— o-o tigmata —0-14""". Of this species, so peculiar and characteristic by the form of its chelae, we have only very little material, so that I can only to a slight degree supplement the description given by Schmidt 1. c. as to the exterior and skeletal structure. With regard to the outer form Schmidt only says, unform- licher, unregelmassiger Korper . The fragments in hand are also of a quite irregular form; the largest one is irregularly bifurcate and somewhat flattened; its extent in length is 25""", but it is probabh only a quite ruined fragment. The colour (in spirit) is yellow to olive. I can sa\ nothing of its sur- face, pores, or oscula. The skeleton appears as a rather irregular network of mosth polyspicular fibres, and longi- tudinal fibres seem especially to be found, while the other network is quite irregular. Upon the whole the fibres are not strongly marked, and no spongin has been observed. Schmidt >a\ s that tin- small form of styli are found as irregular bundles placed obliquely to the fibres; as lai as 1 have been able to see, however, the fact is not s<>. The small styli seem to me to occui near the surface and the dermal membrane, and perhaps partly to be lying horizontally in the skin, partly to project as peni- cillate bundles. Spicula: a. Mcgasclera; these are styli occurring in two different forms, also of different The large styli are evenly curved, the curve being almost always found nearest to the head-end more or less pronounced; the other end tapers to a rniddle-long, sometimes rather long point. Tl length is C59— o-9' , and the thickness is between oxns""" air Finer developmental forms are found, but in rather small numbers. The styli of the other form are smaller; thej are straight almost straight, oiil\ rarely slightly curved. The head-end is quite slightly swollen, most frequently, >i (in the preparations of Van hof feu determined as E. intermedia, which he has lent to Ml>\ the name, and on one of them is added, ist nicht intermedia , so that Vanhoffen seems himself to have noticed the erroneous determination. The [ngolf-F-xpcdition VI. -■• ^2 PORIFERA. II. however, to a quite imperceptible degree. The tapering may be somewhat varying, but the point itself is always rather short. The length is 0-32— 0'40mm, and the thickness in the middle is 0-005 — o-oo8mm. As has been mentioned, these styli, as far as I have been able to decide, occur near the skin. b. Micro- sclera are of two forms, chelae and sigmata. 1. The chela; are of a quite peculiar structure, but must In. characterized as anisocheke palmatae. They are of a wry form; the shaft is somewhat curved, and besides being bent from behind to before it is also bent a little to the side. The tooth of one end is larger than that of the other, and otherwise the teeth are differently constructed. To facilitate the understanding of the description I call the end with the smaller tooth the upper end. When the chela is placed on the back with the upper end turned upward, and the upper tooth directly towards the beholder, and in such a way, that the upper part of the axis is turned directly upward, tben the lower part of the axis is bent a little to the left. The frontside of the upper tooth is then turned directly upward; it reaches to a little more than half the length of the chela, is of a somewhat wry form, and has only a plate-shaped extension to the right; at the upper end a small, triangular tuberculum is found, and there is a small falx. On the upper part of the shaft an ala is only found on the right side; this ala is of a similar form and size as the tooth. When the chela is seen in the mentioned position, tooth and alse are accordingly about opposite to each other. In this position the tooth of the lower end is seen on the left side of the chela, and is seen from the edge, as the front of it is turned out towards the side; it reaches to about the middle of the upper tooth, being therefore most frequently somewhat larger than the latter. If now the chela is turned a fourth part of a turning to the right, so that the upper tooth is seen from the side, the lower tooth will be seen as a warped plate somewhat expanded towards the end, reaching up and bending in towards the shaft; at the base there is a roundish tuberculum. * hi the left side of the lower part of the shaft an ala is found reaching somewhat farther than the lower end of the ala of the right side, but it is rather narrow and bent forward, and is thus rather inconspicuous. Also on the right side of the lower part a small and short ala is found. When the chela is in the position first mentioned, it is seen, that it is especially the lower part of the shaft which is twisted in such a way, that the lower tooth is turned round on the side. In a few of the fragments in hand the chelae are a little larger than in the others, and in these chelae the plate-shaped end of the lower tooth is often marked off by an incision, and this part is finely dentate in the edge. As men- tioned the chelse vary somewhat in size, and seem especially to be varying in different individuals. The length is between o-024,nni auc^ o-o52mm, when the chelae are regarded collectively, but the variation is not so great in the single individual. In one specimen the length was 0-024 — 0"°35mm> m another 0-034 — 0-052'"m. .Schmidt has not quite understood the structure of these chelae; especially his figures a and b are quite misleading; figure c, however, showing the chela from the front, is somewhat better. Carter 1. c, on the other hand, has quite misunderstood them, and it might be doubted whether he has had the same species before him, if he did not mention that he has had a preparation of the type specimen of Schmidt. Carter figures and mentions the chela as an isochela, and he figures uniform alae on both sides of the shaft and uniform teeth, the only deviation from the normal form thus being that the chela is somewhat twisted. This, as will have been seen, is a quite wrong representation, and when Carter thinks that this chela with regard to its structure recalls the diancistra in Hamacantha, and PORIFERA. II. consequently will have these referred to the chelae, his theory is "I no importance. Carter mentions and figures rosettes; I have also seen such, hut they were less distinct than elsewhere in Mycale-species. In the rosette the chelae have the end with the larger tooth turned towards the middle ot the rosette. 2. Sigmata. They are of a regular sigma-form; the ends are with a round curve bent round to about a right angle. They are plane or slightly contort; especially the smallei forms are contort, while the larger ones are most frequently quite plane. They are very much varying as to size, and may be rather large. The length varies from 0-05 — 0-14""", and the thickness proportionally from cr< — 0-0057""". The measures given by Schmidt, are, no doubt, due to an error. As well chelae as sig- mata occur everywhere in very large numbers. In spite of the peculiar chelae of this species, I have placed it under the genus Mycalc, because the elieke must be referred to the type anisochelae palmatae, and its skeletal structure being hitherto only imperfectly known, I have thought it most convenient to keep it in this genus. Locality: Station 78, 60 7 37' bat. X., 27° 52' Long.W., depth 799 fathoms; station 97, 65 -?>s' bat. X., 27 39' Long. \\\, depth 450 fathoms. The former station is on the eastern slope of the Reykjanaes-ridge, the latter in the Denmark Strait. Altogether we have only four fragments. Geogr. distr. Florida, depths 174 — 324 fathoms (Schmidt). 6. M. intermedia O. .Schmidt. 1874. Esperia intermedia O.Schmidt, Die zweite deutsche Xordpolarfahrt, II, 2, 433, Tat'. I, Fig. 40. 1903. Mycale intermedia Thiele, Arch, fur Xaturgesch. 1903, 3S1, Taf. 21, Fig. 12. This species I have not had before me. It would not be possible to recognize it by Schmidt's description, but Thiele has I.e. given a new description of it. Of spicules it has the following form-: a. Megasclera oxea, ca. o-45mm long and croio— croi2mm thick; b. Microsclera large anisochelae palmatae in rosettes, 0-05— o-o6mm long, with the smaller end rather large; small anisochelae palmatae ca. O'OiS the latter do not form rosettes. This species deviates from all other Mycale-species by its diactinal megascleres ; Thiele there- fore says that there may possibly be some reason for separating it from the genus Myeali . but this he will not do, however, as long as only this one species is known, and in this 1 follow him. Locality: Xorthern East-Greenland. Asbestopluma Norman. Erect, stalked forms: I he upper part pcuuiform, or with side-branches issuing from all sides 0/ an axis or collected at its upper end, or the sponge formed like a long-stalked cup. The skeleton is exact. ^ponding to the form, and consists of a spicula-axis often divided into parallel fibres: in this in- serted fibres running one through each side-branch. Sometimes a coat with particular, densely into spicules on the stalk. In t tie skeleton of the axis spongin is found. Spiatla: Megasclera monactinal, \t\li or subtylostyli, and. where a cool is found on the stalk, in this coat minutely spitted fyl tylostrongyla ; microsclera : the characterise microsclera are small anisochelae palmata- of a pccul/ai with a strongly marked contrast he/ween the two ends: to these may be added larger anisochehr pain. and sigmata, or only sigmata or fort /pes. PORIl'ERA. II. The generic name Asbestopluma was used for the first time in 1882 by Ray Lankester, who, 111 .1 paragraph Dredging in the Norwegian Fjords (Nature XXVI, 478) under the sponges mentions Asbestopluma (a new genus of Norman) . As, however, it was nowhere described, nothing was known of it. In 1901 Topsent, however (Resultats du Voy. du S. Y. Belgica, Spongiaires, 23) has rendered an account of the genus and given a description of it on the basis of a preparation from Norman, and then it turned out that Norman had established the genus Asbestopluma on the species Cladorhiza pennatula of O. Schmidt1). Now Topsent thinks, and, no doubt, justly, that sufficient characters are found to justify the keeping of the genus, which will comprise the symmetrical, Clado- rhisa-like tonus which are not, as Cladorhiza, provided with ancorae, but with palmate auisochela;. Topsent, however, wants the genus to be interpreted as a sub-genus of Cladorhiza, only separated from it by the mentioned character. I, on the other hand, regard the genus, exactly on account of its chelae, as most closely allied to Mycale, and therefore I place it just after Mycale as an independent genus. It will comprise all the symmetrical forms, hitherto referred to Esperella, with small anisochelse of the characteristic type more thoroughly mentioned under the different species, either alone or together with other forms of microsclera. Thus the genus is well characterized both with regard to its outer form, its skeletal structure, and its spiculation ; but at the same time it, especially with regard to its outer form and spiculation, divides into three groups that seem to me so strongly marked, that I think it most correct to establish three subgenera for these groups. Asbestopluma Norman s. str. Penniform, lateral branches issuing biserially from an axis, or with lateral branches all round, often, fur, showing a distinct bilaterality. The skeleton a spicula-axis divided info parallel fibres or fibre-like parts, in which axis the fibres supporting the lateral branches are inserted. The stalk is ed with a layer containing particular spicules. Spicu/a: Megasclera styli and subtylostyli, the former in the axial fibres, the latter in the lateral branches, and furl tier irregularly sinuous, minutely spined tylo- styli or tylostrongyla in the coating of the stalk; microsclera: the characteristic anisochelce palmalce are small, the aim of the larger end pass far down towards the opposite end, which is narrow; further always sigmata unci often large anisochelce palmatce. 1. A. pennatula O. Schmidt. PI. II, Figs. 1 — 6. PI. X, Figs. 4a— o, 5 — 7. [875. Cladorhiza pennatula O. Schmidt, Jahresber. der Commiss. zur wissensch. Unters. deutsch. Meere in Kiel fiir 1JS72 — 73, 1875, 119, Taf. 1, Fig. 14 — 16. 1.SS2. Cladorhiza biliamatifera Vosmaer, Niederl. Arch, fiir Zoologie, Suppl. Band I, 47, PI. I, figs. 105 — 112. [885. lisp, ria biliamatifera Armauer Hansen, The Norwegian North-Atlantic-Ex43. XIII, Spougiadae, partim, 15, PI. Ill, fig. 7, PI. IV, fig. 2, PL VII, figs. 5 and 14. ») Topsent 1. c. tells that the preparation of Norman had the inscription «.Asbestopluma pennatula Schultze , but he thinks, ami, no doubt, justly, that this is a slip of the pen for pennatula Schmidt. PORIFERA. [I. 1887. Cladorhiza Nordenskioldii Fristedt, Vega-Exp. vetensk. laktt. IV, 455, PI. 25, figs. 51 1. 31, fig 25. 1896. Cladorhiza Nordenskioldii Lambe, Proceed, of the Roy. Soc. oi Canada, Ser. 2, II, Sect. IV. PI. I, figs. 9, 9 a — f. 1 901. Asbestopluma pennatula Topsent, Resultats <\n Voyage du S. Y. Belgica, Spongiaires, 24 el PI. Ill, fig. 9 a— d. 1903. Cladorhiza pennatula Thiele, Archiv fur Naturgesch. 1903, 385. 1903. Esperclla plumosa Arnesen, Bergens Museums Aarb. 1903, No. 1. 11. Taf. II, Fig. 1, Taf. IV, Fi; Taf.VI, Fig. 7. Slender, penniform ; the axis a little compressed and the more or less long lateral brain lies in- serted 111 Hie narroto tides. The axial skeleton with a rather powerful , close-spiculed exterior la Spicula: Megasclera styli in Hie axis o-68—i""", mbtylostyli in the branches and in the outer layer of the axis 0-52— ojf"", irregularly sinuous, minutely spi unions tylostrongyla in I ho coating 0/ the stalk f the sponge; accordingly the axis is firm and hard. It is, however, not massive, but pierced, throughout its length, b\ a number of canals separated by close-spiculed parts, and the whole structure is outmost surrounded 1>\ a close-spiculed layer. All the spicules are parallel to the longitudinal axis of the stalk. It is no easy thing to get a clear view of the number and arrangement of the canals, as whole transverse sections of the hard stalk are only to be obtained with great difficulty. There are always two rather large canals, one along the middle of either broad side of the axis; then the rule seems to be that on each side of these canals two small ones are found occupying, accordingly, the corner parts of the stalk; thus we have altogether ten canals, but sometimes there seem to be still more. Down in the stalk the structure is about the same, and the two chief canals may generally be recognized, hut most frequently there seem here to be fewer canals and less regularity. In the thickened parts at the base of the stalk many more canals and more irregular ones are seen. To judge from observations on the few root-fragments in hand, the canals would seem also to pass into the root-branches. The stalk is sometimes a little twisted in the lower part, aud then the canals follow the winding always following the longitudinal direction of the spicules. The skeleton of the branches consists of an axis, which may he more or less thick in proportion to the length of the branch, and is constructed of parallel spicules with their end turned outward; it is inserted in the narrow sides of the principal axis between the longitudinalh running spicules of this axis in such a way, that the spicules of two lateral branches placed opposite to each other meet in the middle, and the spicules inserted in the principal axis are spread in a fan- shaped way in the longitudinal direction of this axis. As more thoroughly mentioned below an the spicules, the skeleton of the axis consists of styli with an admixture of subtylostyli especially in the outer part, while the skeleton of the branches consists of subtylostyli. The outside ol the axis i.s. in its lower part, coated with a layer of varying thickness. It is rather firm and compact, showing a smooth surface with here and there some wrinkles and folds. It reaches towards, or almost quite up to the place where the lateral branches begin. It may be of varying thickness, from a scarcely per- ceptible crust to a rather considerable layer, the thickness being greatest towards the base, hut also M With regard to all the symmetrical, branched Mycafe-species i stopluma it is a fact that neither pores nor oscula have ever been mentioned in tile literature. Kithci UO( incut; that they have not been found. Now several things might indicate that this fact with rej is caused h\ the dermal membrane generally being absent on the material obtained for examination. The specimens sometimes show ruined remains of a membranous character, especially at the base of the blanches. Willi regard to the present species it is. perhaps, not improbable, that in the undamaged sponge the dermal membrane is, to a higher or smallei degree, suspended the lateral bunches, so that these are only partly free, ami then pores and oscula are presumably found in this membrane 1: is obvious that such a suspended thin membrane is easih destroyed, as tin | in question is upon the whole from eat depths and may be damaged in the trawl, or to a still higher degree in the swabs, with which instruments mo- tile individuals of the [ngolf-Expedition have been obtained. 48 PORIFKKA II. here somewhat varying. The greatest thickness was measured to about 2"im. 'When the layer is thick it is frequently not of equal thickness all round, but the axis ma}' be placed very eccentrically. In the thickened part of the- stalk the- thickening is often chiefly due to the outer layer, but the axis itself may also he thickened and the layer comparatively thin. The layer is quite compact showing no canals, and is easily separated from the axis itself. The skeleton of this layer consists of exceed- ingly densel) interwoven, winding and finely spinulous tylostrongyla, which, although the layer contains no spongin, are- only to be separated with great difficulty. The spicules of the other parts of the skeleton are united by a mass of spongin, quite clear under the microscope and consequently only to he >ee-n with difficult)'. On a transverse section the axis is seen to be slightly yellowish, while the sponginless coating of the stalk is whitish, and, when dried, gets a quite snow-white colour. Spicula: a. Megasclera; these are the spicules, partly of the skeleton proper, partly of the stalk- coating. The spicules of the skeleton are of two forms: styli, chiefly forming the skeleton of the axis, and subtylostvli, forming the skeleton of the branches, but also occurring in the axis. The styli of the axis may again he divided into two groups: long, slender, most frequently straight ones, and short thick, and curved ones; these two groups, however, are not sharply separated, but connected by tran- sitional forms, while there seem to be no transitions between the styli and the subtylostvli. The styli are fusiform and evenly tapering towards both ends; in the rounded end, moreover, a short, rather abrupt tapering is found, by which the styli are still more easily to be distinguished from the sub- tylostvli; this tapering is most marked in the thick forms. The other end has a short, somewhat stubby point. The length is o-68— i""", the thick ones generally not exceeding 0'875'nm, and sometimes going down to ca. o-6mm. The thickness varies altogether from 0-015— o-032mi"; for the two forms it may be stated to be about 0-015 — o-02im,n, and o-02i — 0'032'n,n. Of the styli the thicker ones, to be sure, are found throughout the axis, but they are especially numerous towards the base. The subtylostvli are slender and straight, the head is only little marked and is placed a little below the rounded end. The point is short and often almost stubby. They are fusiform, tapering a little towards either end. The length varies from 0-52 — 075""", and the thickness in the middle is 0-009— O'Oiy""". As mentioned above, the subtylostvli form the skeleton of the branches, and are also found in the stalk, especially in the outer layer. The spicules of the coating of the stalk are tylostrongyla, minutely and densely spinulous; they are sinuous and curved in very different manners. The head is rather distinctly marked, sometimes it is placed a little in on the needle; the other end is broadly rounded, and the needle is of about the- same thickness throughout its length; sometimes it tapers a little towards the end. The length is between C05 and 0'i37mm, the thickness was measured to O'ooi — O'0028mm. The thinnest forms that have been observed, thinner than 0'00i,nm, are so finely spinulous, that the spinules are almost not to be observed, and the very finest ones are perhaps quite smooth; I suppose them to be developmental ms. b. Microsclera; these- are anisochelse palmatce of two forms and sigmata. 1. The charac- teristic aniso chelae are small and of the structure peculiar to the subgenus. The shaft is curved. The two ends are exceedingly different; the upper end is provided with very large alee folding round on the- side, the tooth is considerably shorter and narrower. When the chela is seen from the side, the axis is seen to bend round below like a hook, and alse and tooth are present in the common way; these parts are very narrow, but they are only t<> he- seen with extreme difficulty, and so it is not PORIFERA. II. possible to state their form exactly. When the chela is viewed with the smaller end turned directly towards the beholder, however, the alas and the tooth are distinctl) seen together with the pari ol the axis between them (PI. X, fig. 4 h). These chelae are very small, their length is O'Oio— o-oi 1 j and the breadth is cvoo57,m". 2- The large anisocheke are of a peculiar structure not quite easily understood. The shaft is about straight. The two ends are ver\ different; the larger one is of th< common Mycale-stmctnie, the alae are much refolded on the side, and the tooth is considerably nar- rower than the ahe; a rather long tuberculum is found pointed downward. The form of this end is rather constant in one individual, but may be somewhat varying in different individuals. The variation consists in this end becoming longer in proportion to the total length, the lower edge of the ahe bending much downward on their way outward from the .shaft so as to form a far out-drawn lo\ corner, and the tooth becoming longer and at the same time narrower. The ahe and the tooth may get so great a length as to reach the structures from the lower end of the chela. The smaller end ol the chela is of a peculiar structure and shows a remarkable irregularity. When the chela is viewed from the front or from the side, some small teeth appear to issue from the lower end. < >uly when the chela is placed with the small end turned towards the beholder, it is possible to get a clear view of the structure. The shaft is then seen to have a narrow ala on either side; next three laps or teeths are generally seen below, one on either side and one in the middle. The middle one is either un- divided or more or less split in two; most frequently it is completely divided, and then we get alto- gether four laps. This is the construction when it is regular, but frequently it is irregular and unsymmetrical, so that we see two laps on one side and only one on the other, or the two laps oi the middle tooth are of unequal size. Also the ahe of the shaft may be unsymmetrical, as upon the whole this end is subject to much variation. The laps or teeth are so thin and transparent, that, when the chela is not seen from the end, they are hardly to be observed. Unfortunately I have found no developmental stages of this chela, and so it is impossible to ascertain how the construction of the smaller end is to be interpreted, whether we have here real teeth, or oik tooth divided into laps, finally the lateral teeth are to be interpreted as belonging to the ahe of the shaft. When two teeth are found in the middle this is surely the result of cleavage, which max also he seen from the fact that in such cases we find a median tuberculum the upper part of which is split. Also the later. 1'. teeth seem to be provided with a tuberculum, but by this fact it is not proved, however, that the\ are independent teeth. Perhaps the developmental forms max soke this question. The length oi the chela is between o-oaN and cn/^'"'", the greatest breadth is ox>22 ooi-""", and the thickness of the shaft is ca. croo4""". As the length is proportionate to the mentioned variation in the form of the upper part, it is rather constant in one individual. The longer the upper end is in proportion to the total length, the shorter is the chela. 3. Sigmata; they have a comparatively little curved shaft, while the tolerably short ends are strongly bent in a hook-like wax. A peculiar feature is that the shaft towards the bendings is compressed, and therefore a little broader, seen from the side. Thex are contort, most frequently a quarter of a turning, and thex max therefore, by a slight glance and under small magnifying powers, recall small tylostyli, as observed by Schmidt I.e. That thex max appear as tylostyles arises from the fact that thi' hook which is turned upward is not seen as a hook, but max- give the impression of a swelling. Then length is .^ nd the thickness about Tin- [ngo!f*E xpedition. \ I PORIFKRA. II. i [ ■'■'■". All the microsclera occur in great numbers in the tissue coating the branches and the axis of the part carrying branches; especially the small chela is found in enormous numbers. Embryos: In most individuals of this species embryos were found. They are oval or round, most frequently a little flattened, of a diameter of 0-5— ca. imm. They were frequently seen to be sur- rounded by a quite clear and transparent membrane. They occur in different, sometimes rather great numbers, and are situated in the mentioned axial canals. Most frequently they are placed in a single row in one of the principal canals (PI. II, fig. i|, but they may also be found in the side canals, and they may be so densely crowded as to cause larger or smaller swellings (PI. II, fig. 4). With regard to spiculation they show some differences that are rather interesting. They have only sigmata and tlic small anisoehelse. Sigmata seem to be the form of spicules first occurring, and in some specimens only these occur. In some specimens the sigmata, or most of them, were somewhat smaller than those of the developed individuals. While in the larger embryos sigmata and cheke were found in verv great numbers, the}- were scarce in others, and in some of the embryos no spicules seemed to he present at all. Remarks to the synonymy. I have been able by examination of one of the specimens of the Barents-Expedition to identify as pennatula the species mentioned by Vosmaer I.e. as Cladorhiza bihamatifera. Vosmaer mentions it as a difficult thing to get a clear understanding of the large chelse and savs, - I now believe that they are to be considered as jEr/r/w-aiichorates, where all the teeth are fully developed, and not two with one rudimentary . What is meant by this phrase is unintelligible, as the larger end of these chelse is of the same structure as in all common Mycale- ehelse. — Of Armauer Hansen's material I have examined a few specimens which proved to be pennatula, but under his bihamatifera several species are mingled together; from the figures it may however with rather great certainty be decided, which of them belong to the present species. Of Fristedt's Cladorhiza Nordenskioldii I have examined a fragment of the type specimen, which proved it to be pennatula; Fristedt must have overlooked the small cheke. Also Lambe I.e. must have overlooked these chelse, as the Cladorhiza Nordenskioldii mentioned by him is certainly identical with pennatula. It is easily understood that he has overlooked them, as he has had only the lower part, where the small chelse only occur much scattered. Finally the E. plumosa established in 1903 by Arnesen I.e. is identical with A.pennatula, which fact I have been able to decide with certainty, as I have examined a fragment of one of the type specimens. In the quite insufficient description no account is rendered of the two forms of chelse; the length of 27™™ given for the megascleres must be due -to an erroneous measuring; in the specimen examined by me I have found none larger than o-95mm. Locality: Of this species the Ingolf-Expedition has obtained a great number of specimens. Station 6, 630 43' Lat. N., 140 34' Long. W., depth 90 fathoms; station 39, 620 00' Lat. N., 22° 38' Long. \V., depth 865 fathoms; station 40, 62 oo' Lat. N., 21° 36' Long. W., depth 845 fathoms; station 67, 6ic 30' Lat. N., 220 30' Long. W., depth 975 fathoms; station 68, 620 06' Lat. N., 22° 30' Long. W., depth 843 fa- thoms; station 78, 6o° 37' Lat. N., 27 : 52' Long. W., depth 799 fathoms; station 81, 6i°44'Lat. N, 27° 00' Long. W., depth 485 fathoms; station 94, 640 56' Lat. N., 36" 19' Long. W., depth 204 fathoms; and station 144, 62 49' LatN., y 12' Long. W., depth 276 fathoms. On station 78 the greatest number of specimens PORIFERA. II. -, were taken. The stations are situated between the Faroe Islands and Iceland, south of Iceland and in the Denmark Strait at the eastern coast of Greenland. The depths vary from 90—975 fathoms: the bottom temperatures on the stations were from 1 6 til 7 oC. Further I have before me one speci- men from the northwestern coast of Norway, Lyngeu, depth 160 fathoms (O. Nordgaard). Geogr. distr. The species is further known from the following localities; off Bukenfjord and Haugesund, depth 106— 115 fathoms (Schmidt 1. c.) ; Tronhjem Fjord (Arnesen I.e.); the Barent Sea, depth 220 fathoms (Vosmaer); the east coast of Greenland, depth 130 fathoms (Fristedt); the Gulf oi St. Lawrence, depth 200 fathoms (Lambe). Accordingly the species is a northern one. and has hithi been found from about 2y 20' Long. E. to about 650 Long. W., and between 5" and 74 10' hat. X. As is commonly the case, it reaches considerably farther south at the American coast than at the Euro- pean; thus at the coast of Norway it has only been obtained to about 590 Lat. N. 2. A. bihamatifera Cart. PL II, Figs. 7— 8. PL XI, Fig. 1 a -g, Fig. 2. 1876. Esperia cupressiformis var. bihamatifera Carter, Ann. Mag. Nat. Hist. Ser. 4. XVIII, 318, PL XIII, fig. 14, PL XV, fig. 34a— b. Shorter or longer lateral brunches pass off from the axis all round. The axial skeleton is divi- ded into a number of fibres, between zvhich the fibres of the lateral branches are inserted; outmost in the axis a thin layer of spicules is found. Spicula: Mcgasclera styli in the axis o-6j—roimm, subtylostyli in the branches and. in small numbers, in the axis o-y\ — y : , and the thickness the shaft is about 0-005""". 3. Sigmata; these are of the same form as in pennatula with only little curved shaft and short ends, bent in a hook-like way. The shaft is likewise compressed or sh like an edge inward towards the bendings, and they are contort, most frequently a quarter oi a turning. The length is 0-018—0-021""", the thickness in the middle is ca. 0-OOlmm. The microsi in large numbers in the dermal membrane and in the tissue of the p; inches. As will have been seen, this species is verj closely allied to the preceding one. and differs ca PORIFBRA. II. from it especially by the facts that the branches are polyserial and the spined tylostyli of the coating layer more pointed, and these two characters are constant and are found together in all the material I have examined. It will also have been seen from the description that the skeleton of the axis is constructed in a somewhat different way. After Carter's descriptions and figures I regard the iden- tification as certain, as both the spicula-figures, especially that of the large chela, agree very well, and also the figure of the exterior of the small fragment Carter had show that the question is of a species with branches arranged polyserially. Of Armauer Hansen's figures of exteriors those on PI. VII, figs- 2, 3, and 15 might perhaps be bihamafifera, but as it is said in the text that only one of all the specimens had sigmata, the question is more likely of the species lycopodium. The question cannot be decided with certainty, as the fact that sigmata of two different specimens are figured, both on PI. Ill, fig. 5, and PI. IV, fig. 2, shows that the quoted statement is wrong, and I have also examined two specimens, which were both of them pennatula and consequently both provided with sigmata. Locality: Station 15, 66° 18' Lat. N., 25° 59' Long. W., depth 330 fathoms (bottom temperature -ho°75C); station 59, 650 00' Lat. N., n° 16' Long. W., depth 310 fathoms (bottom temperature h-o°iC); station 126, 6jc 19' Lat. N., 150 52' Long. W., depth 293 fathoms (bottom temperature -4-o°5C); station 138, 630 26' LaL N., 70 56' Long. W., depth 471 fathoms (bottom temperature -=-o°6C); altogether eight specimens. The stations are situated in the Denmark Strait, north and East of Iceland, and north of the Faroe-Islands, and they are seen all to belong to the cold area with negative bottom temperature. It is of interest to see that this species, which is so closely allied to the preceding one, from which it differs only by slight, but constant characters, occurs exclusively in localities with negative bottom temperature. Gcogr. distr. With regard to the specimens of the present species from the Norwegian North- Atlantic Expedition the more particular localities are not known; if the species are represented in the material, it must be supposed to have been taken on one of the stations in the cold area. The locality is also wanting for the specimens of Carter, but on account of other sponges in the same jar he thinks that the locality ma)- possibly be in the western entrance of the British Channel. This is probably not the case, however, as the species is a native of colder bottom, and I suppose that Carter's specimens originate from one of the cold stations of the Porcupine . 3. A. furcata u. sp. PI. II, Figs. 9 — 10. PI. XI, Fig. 3 a — h. The axis slender, dichotomously branched once or several times. The lateral branches very short, placed all round, only on the upper ramifications. The axial skeleton divided info fibre-like parts, out- most a thick layer 0/ spicules. Spicula : Megasclcra styli in the axis o-jp — 0-65""", subtylostyli in the branches and outmost in the axis, 0-268 — o-j6""", curved, finely spiuuloi/s tylostrongyla in the coating of the stalk 0-068 — o-oyy""; microsclera of three forms, aniso chela palmatcr of two forms, the characteristic ones o-o/o— 0-014""". the large ones with unsplit or split lower tooth v 041—0-054""", sigmata 0-015— o- 01 jmm. This species is of a very slender form; it begins below with a stalk that gradually branches dichotomously. The most ramified specimen branches three times, so that the two branches formed PORIFKRA. II. rr in the first instance divide again, and the newformed branches divide also. In one specimen one branch divides into three, sending off two lateral branches while the principal one itself continues in the middle. In another specimen a coalescing of two stalks lias taken place; as the lower part of the specimen is wanting it cannot be seen, whether the two branches belong to one individual two different individuals are coalesced. The stalk is somewhat widened below and has been attached to some firm object. The stalk may be straight or somewhat curved, and it is about cylindrical. On the ramifications lateral brandies are found more or less extensively; they are generally only found on the outmost ramifications, sometimes also some way down the branches below the last division. Thus in the smallest specimen, which has only two branches, they are found some way down the stalk. The lateral branches are small, almost scale-like and most frequently very much directed upwards, sometimes almost quite adpressed. They are arranged in several rows, but very irre- gularly, so that the rows in some places are close together, while at other places the intervals are greater. The axis is slightly compressed in the parts carrying lateral branches. The branches end with a compressed part forming an extended, and on account of a little notch somewhat heart-shaped, head. Perhaps the question is only of a beginning new cleaving. In a single fragment the last ramifications end without this head, and this is perhaps a specimen in which the growth has ceased. The stalk has a thin coating of the common nature, and this layer generally reaches far up, often to the last, or last but one. division. The largest specimen in hand, the above mentioned most richly branched one has a height of 140™'", the stalk to the first division is 35'"'" long. The smallest specimen, which is only divided once, is 65'""1 high. The species, as mentioned, is very slender, the stalk of the largest specimen has only a diameter of 2""", and farther up the thickness is 1 — v$mm. The lateral branches do not reach more than imm in length. The consistency is of the common firmness. The colour (in spirit) is whitish yellow to light brownish; the coating layer of the stalk is always a little darker. The surface is smooth, but on the part with branches it appears under the microscope to be shagg\ from the projecting chela;. No distinct dermal membrane was seen; outermost in the skeleton a dense layer of spicules is found, and outside of this a thin layer of tissue, copioush provided with miero- scleres. Oscula and purrs were not observed. The skeleton. The skeleton of the axis consists of closely united, parallel needles. Through the axis run a number of canals, which in the ramigerous part seem to be arranged in .1 more or less ringlike way, and are separated by narrow parts of spicules, as also the fibres ol the lateral branches, where such are found, pass in between them. Lower down in the stalk the canals are not regularly arranged, so the separating spicula-parts are also here, when seen in transverse sections, irregularh sinuous. Accordingly, the skeleton of the axis is by the canals divided into tildes 01 narrow, fibrelike parts. Outmost a dense layer of spicules is found, which is most frequently rather easily loos< on the stalk below the ramigerous part, while 011 this part such is not the case, and here where the lateral branches are inserted, the needles ..i this layer do not exactly run in til tion of the longi- tudinal axis. In the lowei part of the stalk the axial skeleton is twisted in .1 spiral manner. The skeleton of the lateral branches consists of bundles of spicules ; they are inserted between the spicules oi the axis in the common way, and reach to, or about to, the middle. The skeleton of the axis cons of styli, among which in the outer layei of spicules shorter subtylostyli are intermingled; the skeleton oi 56 I'ORIFKKA. II. the lateral branches consists of short subtylostyli. The skeleton of the coating layer of the stalk consists of closely interwoven, finely spinulous tylostrongyla. The spicules of the axis are united by a clear mass of spongin. Spicula: a. Megasclera; these are the styli of the axis and the subtylostyli of the lateral branches, besides the spicules of the coating layer of the stalk. The styli in the axis have in this species no abrupt tapering towards the head-end, and as the subtylostyli show most frequently an almost indiscernible swelling, the difference between them is chiefly to be sought in the size. The styli, to be sure, vary somewhat in form and size, but they cannot here be said to be divided into two groups. They are straight, or slightly, only rarely a little more highly, curved; they are slightly fusi- form with the greatest thickness in the middle. The point ma}- be a little varying, but is always short or rather short; most frequently it is bounded by straight lines. The length is 0-39 — o'65min, the extreme measures, however, occurring rarely. The thickness, which has no definite proportion to the length, is between o-oiomni and o-024mm. The subtylostyli are straight, only sometimes quite slightly curved. They are only a trifle thicker in the middle than towards the ends; the head, which is placed a little down on the needle, is generally a scarcely perceivable swelling; the point is short, but bounded by straight lines. The length is 0-268— o'36mm, the thickness is 0-007 — o-onimn. The spicules of the coating of the stalk are minutely spinulous tylostrongyla; they are more or less irregularly curved, most frequently to a rather slight degree. The head is round and distinctly developed, the}' do not taper much towards the opposite end, and this end has a little swelling, so that in form they approach tylotes. They are smaller than in the preceding species, the length is 0-068— o-095m111, and the thickness about o-ooimm, a little more or less. b. Microsclera are anisochelae palmatse of two sizes and sigmata. 1. The characteristic small anisochelse are of the type of the subgenus, and are of the same form as in the preceding species; the}' are, most of them, o-oiomm long and o-oo5'nm broad, but chelae may be found reaching to a length of o-oi4mm. 2. The large anisochelse are also of a similar form as in the two preceding species. The shaft is straight; the larger end is about half so long as the whole chelse; the tooth is considerably narrower than the alae, it is broadest below, and rather straight cut off with rounded corners or sometimes more rounded; a long, down- ward pointed tuberculum is found. The smaller end is more regular than in the preceding species, and its form is more like that of the common type. The shaft has a pair of short ala;, rather broad above, and forming together a triangle; then there is a curved tooth of similar size, most frequently, however, a little shorter than the aire. As the tooth is in a rather oblique position to the shaft, it appears -always somewhat shortened, when the chela is seen exactly from the front, and its curved form is also seen. Accordingly, when the tooth has this form, the structure of the smaller end is quite normal; the tooth, however, is often split into two lobes, and the splitting may be more or less pro- nounced ; lateral lobes, however, are never found. Also here the tooth is so thin and transparent, that a clear view of the form can only be got by regarding the chela from the end. The length is 0-044— o-054'"m, the breadth about 0-02 irom, and the thickness of the shaft is about o-oo4mm. 3. Sigmata are of the same form as in the preceding species with the same edge-like expansion of the shaft towards the ends, and the}" are also contort. The length is 0-015 — o-oi/""", and the thickness about o-ooi,nm. All forms of microsclera occur in great numbers in the tissue. PORIFERA. II. Embryos. In this sponge embryos were most Erequentl) found; the} occurred partly in the uj ramifications, partly somewhat lower down. The) were, as far as I could see, situated in the canals just inside the outermost layer of spicules, but each embryo appeared to he inclosed in a cavity of its own, and the places in which the} occurred were a little swollen and thus fusiform. The embryos are roundish or oval, and have an average diameter of 0-$""". In contradistinction to the embryos found in pcnnatula, both megascleres and microscleres are found hue. The megascleres all subtylostyli ; they are similar to those in the grown individual, but are often a little more curved, and the head may be marked off in different ways; the)' have also on an average a somewhat longer point. The>- are smaller than in the grown sponge and have an average length oi .Of micro- scleres only the small chela and sigmata are found; both of them are full}' developed, and the) show a peculiar and surprising feature, being both a little larger than in the grown sponge. Thus sigmata reach a length of o-02iram, and the chelae are 0-0114 — O'oij}""" long. According to this it must In- sup- posed that the first formed of these chelae and sigmata are a little larger than the final form, which appears later. Chelae and sigmata are present in great numbers. The embryos seem here to leave the sponge by a bursting of the wall, the outer layer of spicules being in several places swelled out by the embryos underneath, and in a few cases a hole and an empty cavit\ are seen. Locality: Station 101, 620 23' Lat. N., 12' 05' Long. W., depth 537 fathoms (bottom temperature -f-o°7C), one specimen. Further it has been taken on 62 53'Lat.N., 4 14' Long. E., depth 450 fathoms, one specimen, and east of Iceland without an) statement of depth, five specimens (Ad. Jensen, the cruise of the Michael Sars 1902). The localities are situated east and northeast of Iceland, and at the coast of Norway. With regard to the two last localities no bottom temperature has been given, hut thev are situated in the cold area, and thus this species is also a native of the cold bottom. Note. Of Arm an er Hansen's figures to Esperia bihainatifcra (The Norwegian \ Atlantic Exp.) I am inclined to suppose, and I think there is great reason for supposing, PI. VII, Kg. 4, and especially PI. Ill, fig. 5 to be the present species. As will have been seen, the species of this subgenus are distinguished b) a peculiar coatiu« layer on the stalk. At first one might he inclined to think that the question was of a separate sponge incrusting the stalk of these sponges, as is also pointed out 1>\ Topsent b) the men- tioning of fiennatula and Belgica I.e.; hut the constant occurrence of the layer, and the difference ^\ its spicules in the different species proves it to he a formation belonging to the sponge. Those species of the subgenus of which rather intact specimens have been examined, show a formation of roots. This formation is connected with the fact, that the) are no doubt sunk into the bottom of thf it would seem, with a \cr\ long part of the stalk. I suppose that this is also til >n why the) are provided with the coating layer. The species ftircata, however, is an exception, as it is not sunk into the bottom, hut is attached with its base. Nevertheless it has the coating layer, hut it is \ thin and shows the peculiarity that it reaches ver\ far up, often to the lasl 1 .unifications. The [ngolf-Expedition VI. 2. -g PORIFERA. II. Lycopodina n. subg. Lateral branches issuing all round from an axis, or the branches collected in the upper end of this axis: sometimes the lateral branches ore more or less coalesced. The skeleton consists of a spicula- axis, and the branches are supported by fibres inserted in the axis, or in other ways connected with it. Spicula : Megasclera styli or subtylostyli; mic rose /era: the characteristic anisochela- palmatce are small, the a lie of the larger end pass down quite to the opposite end, which is rather broad ; to these spicules forcipes are most frequently added. 4. A. cupressiformis Cart. PI. II, Figs. 11-14. PI. XI, Figs. 4a— f, 5. 1N74. Esperia cupressiformis Carter, Ann. Mag. Nat. Hist. Ser. 4, XIV, 215, partim, specimen in inter- elusione commemoratum exelnsum, PI. XIV, fig. 16 a. — f., figs. 17 — 18, PI. XV, fig. 37. [885.? Esperia bihamatifera Armauer Hansen, The Norwegian North-Atlantic Fxp., XIII, Spongiadce, partim PL VI, fig. 1, PI. VII, fig. 1. 1886. Esperella cupressiformis var. robusta L,evinsen, Dijmphna Togtets zool. hot. Udbytte, 364, 18 a, Tab. XXIX, Fig. 10- 1 1, Tab. XXXI, Fig. 7— 14, 16 a, b, c. [887. Cladorhiza cupressiformis Fristedt, Vega-Exp. vetensk. Iakttag., IV, 457, PI. 25, figs. 66 — 69, PI. 31, fig. 27. 1900. Esperella Fristedtii Lambe, partim, specimina dua e tribns commemoratis, Transact, of the Royal Soe. of Canada, Ser. 2, VI, Sect. IV, 21, PL I, figs. 2, 2 a. — e. Irregularly situated short /ate rat brandies pass off all round from the axis, or the branches coalescing to a curled surface; sometimes all the upper part or only the uppermost portion o_p it leaf- shaped, flic skeleton consists of a spicu/a-axis, the ramigerous part is supported by an irregular skeleton. from which the fibres of the lateral branches pass off. but they are not inserted in the axis. Spicule/: Megasclera subtylostyli or styli o'3j—o'84mm; microsclera of two forms, the characteristic anisochelm palmalic 0-023 — o'02jmm, forcipes 0-038 — 0'0/f.8mm. This species is of a slender, erect form. Below it consists of a more or less long stalk, all but cylindrical, which is most frequently one fourth of the total length. The upper part is somewhat thicker than the stalk and carries a number of short lateral branches, placed irregularly, and issuing all round. These branches may be very short, so that they almost do not project over the surface, or there may between them, or instead of them, be found low ridges especially running longitudinally, and then the upper part shows only a highly wrinkled, folded, or curled surface; but in most cases the projections are formed as cylindrical, a little conical branches rising with a broad base from the axis. They reach at most a length of about 3"1"1. Sometimes the sponge is above widened to a small leaf-shaped part (PL II, fig. n), and one specimen consists of a quite short stalk passing into a broad, rather thin leaf with a grooved and wrinkled surface (PL II, fig. 12). Below the sponge is attached by a somewhat widened part of the stalk. The specimens in hand from the territory treated here are lorn off from the substratum, but specimens from the Kara Sea are attached to shells (Astarte sp.), worm-tubes (Spiochatopterus typicus and especially Pectinaria hvperborea), and to pebbles. The largest PORIFERA. II. 59 .specimen (from the Kara Sea) has a length oi ca. [35"™, the stalk is 26"" long, the greatest thick: is 7 ', and the stalk is ca. 2mm thick. Then we have specimens of all sizes downward, the smallest specimen is 15""" high. The mentioned leaf-shaped specimen has a height of 77 ', and a breadtl ca. 70"1'", its stalk is only 13""" long. The consistency of the upper part of the sponge is softer than in the preceding species, the stalk is hard. The colour (in spirit) is whitish gray to whitish yellow. The surface, apart from the nature described above, must lie said to he smooth, only in tin- ends oi the lateral branches bundles of spicules project. In the specimens in which no lateral branches 1 perly so called are found, but only longitudinal ridges and irregular projections, spicules project through these, and thus these individuals get a more shaggy appearance. Under the microscope also other parts of the surface may appear shaggy from the projecting chelse. The upper part of the stalk is smooth, but it becomes shaggy towards the base. A dermal membram ma\ distinctly be observed, and is easily isolated; it is thin and transparent and highly filled with chelse, on the other hand there is no dermal skeleton proper, but the membrane rests on the skeleton below, and when it is isolated, needles may be seen scattered in it. Pores have not been observed in the dermal membrane. Ost itla: the mentioned lateral branches act, no doubt, as oscula; the fact is, that these branches are not solid, but are chiefly formed by the dermal membrane, which is here supported by spicules parallel to tin longitudinal axis of the branches. If a branch is cut off it is seen to be hollow, and leaves a hole; on the other hand, an osculum is not distinctly seen at the point of the branch, as the spicules are here closer joined. As the branches are very numerous, and as pores have not been observed, it might be supposed that also the iuhalent system was connected with the branches; it is, however, more prob- able that the pores are closed. The skeleton. The skeleton of the axis consists of close-lying spicules parallel to the longitu- dinal direction. The axis, however, is not quite compact, the spicules being collected mio close-lying fibres; in the interstices an irregular reticulation of spicules is found, which spicules are placed obli- quely to, or across of, the longitudinal direction; sometimes, however, this feature is little prominent, and then the axis is more compact. It continues from the stalk up through tlu sponge, quite to its uppermost end, and it keeps about the same thickness. The outer skeleton, which supports the u] part, consists of a quite irregular net-work of spicula-bundles and scattered spicules, with short fibres here and there. As mentioned, the lateral branches are supported by spicules apparently formiii fibre, but really only supporting the wall of the branch; these spicules do not reach to the axis, but pass only into the other skeletal net. In the lower part of the stalk, where it is shaggy, spicules woven into it, projecting more or less horizontally, and oxer the surface. A coating with special spi- cules is not found. In the mentioned leaf-shaped specimen the skeletal structure has been modified in an interesting manner; the short stalk continues as such onh a short wax into the leaf, and then it is lost. It does not cease, however, but is, as it were, spread in the plate, rather close-lying fib radiating towards the edge, running through the plate;' these fibres correspond to those oi the axis, and they are, like those, connected by spicules and spicula-bundles, which are placed trausversel; obliquely in the interstices. This whole structure forms a thin skeletal plate in the middle of the leaf- shaped part, and on both sides is found a tissue with a skeleton constructed in the same inauuei as tlu- skeleton outside tlu axis in the othei individuals. In the axis the spicules aie united by a rathe: 6o PORIFERA. II. copious, but white and clear mass of spongin, which is most developed towards the base; in the >keleton outside of the axis, on the other hand, no spongin seems to be present. Spicula: a. Megasclera are long, slender subtylostyli, sometimes styli. They are straight, or slightly, most frequently somewhat irregularly curved. The head-end is only very slightly swollen, the opposite end tapers evenly to a rather long point which is often somewhat more abruptly pointed at the end. The needles are here of only one kind, and are the same in the stalk and in the other skeleton, the only difference being that in the lower part of the stalk they become gradually shorter, and the needles that here project and make the stalk shaggy are also short. These short needles are generally more highly curved, and are most frequently styli without any head-swelling, but they cannot be separated from the others as a particular kind. The length is between ca. 035 and cr84m,n, but in these measures are also included the needles occurring towards the base of the stalk; if the lower part of the stalk is excluded the lower limit of the length may be put to about o-5",m, and in a spicula- ] reparation in which no sample from the lower part of the stalk has purposely been added, the length of the needles therefore will be found to be ca. 0-5 — o-84'nm, and the shorter ones will only occur more rarely. The thickness varies from ca. o-oo8 — o-oi4mm ; the longest ones are not the thickest. Finer, to quite fine developmental forms are seen in small numbers, b. Microsclera ; these are of two forms, aniso- chelre palmatre and forcipes. 1. The auisochelse are of a form characteristic of the subgenus; the larger end is of a similar form as in the preceding subgenus; the ahe are very large and reach far down, quite down to the lower end, and there is a considerably shorter and narrower tooth. The smaller end is of a peculiar structure, not easily understood. When the chela is lying on the side a pair of small points are seen at this end, one at the outer end of the axis, the other a little higher up. The best view is got when the chela is seen in such a way as to turn the smaller end directly towards the beholder (PI. XI, fig. 4 c!), and then it is seen that ake and tooth are present as usual. The peculiar feature is that the aire do not run along the shaft in the common way, but are placed almost transversely on it. The axis then continues with a slight bend, and at the end of it the tooth is placed parallel to the aire; it has a distinct tuberculum. When the aire and the tooth are seen from the side, they are seen as the mentioned two points. When the chela is viewed from the front under sufficiently high magnifying powers, a pair of refractive ridges are seen about where the aire of the upper end cease; these ridges are the upper part of the aire of the lower end where they go off from the axis; they are here the most narrow, but downward they become gradually broader, and fold round on the side; the whole thing might be described by saying that the upper outer corner of the ala had been cut .away by a large cutting rounded inward. The tooth, which is also somewhat curved, has a I'M 111 corresponding to that of the alse, being also most narrow above, but increasing in breadth down- wards, and thus showing the same cutting. The folded sides of the aire and the tooth meet on the side leaving only a narrow opening between them; as a consequence of the form the lateral edges are here short. The described form of the aire and the tooth, together with their position with regard to the axis, is the cause win- they appear as two points when viewed from the side under small magni- fying powers. The anisochelre are 0-022 — o-025m,n long1) and ca. ooi2min broad. Developmental stages 1 1 A few chelae were seen of a length of o-oi4lnl", but they, no doubt, belong to the embryos present in the sponge, see below under Embryos. I'ORII'ERA. II. o f this chela were found abundantly on .ill stages from so fine oiks, that the) are hardly to he seen. Levin sen I.e. lias already given an account of the development oi this spicule. - The construction of the lower end of this chela has never been correctly understood, and neither Carter's nor Fri- stedt's figures are correct. Lcvinsen, on the other hand, has given good figures, I.e.; the lower end on PI. XXXI, fig. 7, cannot, however, appear as it is figured, when the chela is seen in the stated position, but only, if it is seen considerably more obliquely from one end 01 the other. Neither has Leviusen clearly understood that the question is of the common parts, ahe and tooth, in a somewhat modified shape. 2. Forcipes. These are of the common form with a round bend above; the legs are parallel or more or less diverging, and cud in a small swelling; the upper part between the '. is somewhat thickened, and appears, especially when the forceps is seen from the side, as a tubercle- like swelling. The length is 0-038 — o-048mm, and the thickness above is ca. q' Long.W., depth 388 fathoms (bottom tempe- rature -j-o 4C); we have it further from the following localities: 01 30' I. at. \\. 1 26 Long.W., depth fathoms (bottom temperature -^ 04 C.| (Wandel); 70 32' bat. X., S [o'Long. W., depth 470 fathoms (the East Greenland Exp. [890—91); 620 40' Lat. N., 1 56' Long. E., depth 365 fathoms (bottom temperature -f-o°3 C); 6o: 09' Lat. N., 5'-" 22' Long.W., depth 620 fathoms (bottom temperature : ■ ; ( (Ad. Jensen, the cruise of the .Michael Sars 1902). Nine specimens have been taken in all. The localities are situ. east and west of the Faroe Islands, west of the Shetland Islands, between the Faroe Islands and N01 way, and south of Jan Maven. Geogr. distr. The Kara .Sea, depths 51 81 fathoms (Levinsen), the Baffin Bay, depth 130 fa ■i As these sponges are most frequently highly filled with embryos, it will generallj be the fact, that euibryonl cules are found in the spicula-preparations, and by judging of the spiculation attention must be paid to this fact The Ingolf-E ipedition \ I 66 PORIFERA. II. thorns (Lambe). Also this species seems to be a native of the cold bottom; to be sure, a bottom temperature of 4 S C. is stated for station 44; but in its immediate neighbourhood, on station 43, so low a positive temperature as o°5 C. is found. It is worthy of notice that in the three species of the subgenus Asbestopluma and the two /. vcopodinar&pzcies now treated, which are in all principal respects of the same outer form, the skeleton cf the axis is formed in a somewhat different way. In pennatula only few spicules are found in the middle of the axis, and also between the canals only narrow spicula-parts occur; outermost, on the other hand, there is a powerful spicula-layer, to which the firmness of the axis is especially owing. In bihamatifera a circle of powerful fibres is found, and outermost only a thin spicula-layer. In furcata the axial skeleton is divided into more or less narrow spicula-parts, and outermost is found a rather powerful spicula-layer. In cupressiformis we find a strong skeletal axis situated in the middle, the spicules of which may be more or less gathered into fibres, which are then connected by a network of not parallel spicules. In lycopodiitm, finally, there is a circle of separate fibres, and here no spicula- layer is found outermost. 6. A. hydra n. sp. PI. II, Figs. iS, 19. PI. XI. Fig. 8 a— f. Formed like a tree with branches issuing from the upper end of a stalk. Tlie skeleton consists in the stalk op a spicula axis, in the upper end of which the fibres of the branches are inserted. Spicula: Megasclera subtylostyli, in the axis o-jy — o-S""". in the branches o-jj — o-6o"""; microsclcra of one form, anisochelce- palmatce of the characteristic type 0-012 — o'oij""". This small Lycopodina-species is of an exceedingly beautiful and elegant form. It consists of a stalk ending in a swelling above, from which issues a number- of thin, undivided branches. Below it is by an expanded basal part attached to a small stone, a lump of sand, or the like. The stalk is cylindric and straight. The sponge is of small size, the largest specimen is i2'"m high, and the greatest length of the branches is 4 — 5mm. The stalk is only ca. o-i5'nm thick, and the branches ca. o-05mm. The smallest specimen is 5mm high. The branches may be of somewhat varying length, and in a fewr cases they are quite short or almost wanting. In the latter case the upper side of the swelling is densely shaggy from projecting spicules, which, as far as I have been able to decide, belong to the thinner form, occurring in the branches. The swelling, from which the branches issue, seems also to be always larger and more compact, when the branches are quite short or wanting, than when they are present in their full length; therefore I am also here inclined to think that the branches are able to contract. The consistency is firm, as the greater part of the sponge consists of spicules with com- paratively little soft tissue, but the sponge is flexible and elastic. The colour (in spirit) is white or slightly whitish yellow. The surface is smooth on the upper part of the stalk and the branches, only in the ends of the branches the spicules project. The lower part of the stalk and the basal expansion PORIFERA. II are shaggy from projecting spicules. On the stalk and the branches only a very thin layer of tissue is seen; on the thickened part between the bases of the branches, on the othei hand, there is a thicker layer of tissue, which is bounded outwardly bj a dermal membrane, supported by no particular skeleton, but provided only with microscleres. Pores and oscida were not seen. The skeleton. In the stalk the skeleton consists of needles closely united and parallel to the longitudinal axis. The spicula-axis formed in this wax divides above into a numbei oi mon oi less distinctly separated fibres bending a little outward, and between these fibres those of the branches are inserted. These latter fibres also consist of closely united, parallel spicules. As will be more par- ticularly mentioned below, the spicules of the stalk are thicker and more fusiform, those of the branches more slender and less fusiform. In the stalk a rather slight amount of ver) clear spongin is found. Spicula: a. Megasclera are subtylostyli of two forms, those of tin- stalk and those of the branches. The subtylostyli of the stalk are straight, rather thick, and highly fusiform, tapering much towards the head-end; the tapering may otherwise be somewhat varying. The) have a head-swelling which is most frequently inconsiderable, and almost always placed a little below the end. The oppo- site end tapers from the middle evenly towards the point, but the end itself is somewhat more abruptly pointed, especially in the thicker ones. The length is rather varying, from 0-47 — o-Smm, and the thickness from 0-017 — o-028mm, the thickest ones being far from always the longest ones. The spicules of the branches are likewise straight, or ver\ slightly curved, fusiform subtylostyli, but the) are somewhat slenderer than those of the stalk, and so they are not so markedly fusiform as those. The swelling of the head-end is a little more pronounced, and is also here placed a little below the end. The opposite end is long and evenly tapering. Their length varies between 0-35 — o-6mra, and the thickness varies proportionately between o-oo6 — 0'0i4mm. As mentioned above the larger spicules form the skeleton of the stalk, and the smaller ones that of the branches, which is formed exclusively by these latter. but they may also be found in small number in the periphery of the stalk, and the spicules projecting in the lower part of the stalk are of this form. Thus the two forms of spicules have each of them a special place of occurrence, and they show also so much difference as to form, that they ma) generally be referred at once to their separate group. It is, however, scarcely to be supposed that they form two fundamentally different forms, as transitions are found between them, ami these transitional forms occur exactly at the place where the stalk and the branches pass into each Other. Here, in the thick- ened part, from which the branches issue, transitional forms are found that may be referred to one form as well as to the other. The basal expansion is formed by both kinds of spicules, the prominent ones seem chiefly to belong to the smaller form; but here again the two forms are not sharply separated, but transitional forms occur, b. Microsclera; these are of one kind only, auisochelae palmatse of the Lycofiodma-type; the) have a form quite similar to that of the chela in the two preceding species, but they are a little smaller, the length is o-oi ! o-oi4m,n, most frequently, however, the latter length; the breadth is < >-( h >=,"""■ The chelae, as usual, occur throughout the tissue, but especially numerous in the dermal membrane. Locality: of this small, interesting, and beautiful species, which is easily recognizable by its outer form alone, the tngolf-Expedition lias obtained fifteen specimens in all; most of them were no; found till after the return of the Expedition, when they were discovered in the bottom specimens 58 PORIFERA. II. growing on pebbles and particles of gravel. Station 113, 690 31' Lat. N., 70 06' Long. W., depth 1309 fathoms (bottom temperature -f-i°oC), thirteen specimens; station 119, 670 53' Lat. N., io° 19' Long. W., depth 1010 fathoms (bottom temperature -f- 1 o C), two specimens. Thus also this species is a native of the cold bottom, and it is only known from great depths. Both the stations are situated between Iceland and Jan Mayen. Cotylina n. subg. Formed like a calyx (or head) on a rather long stalk. The skeleton consists in the stalk of a spicula-axis, in the calyx-wall of more irregular arranged spicules. Spicula: Megasclera styli or sub- tylostyli, often divided into several forms occurring in fixed places in the sponge; microsclera: the cha- racteristic anisochehe palmatie have the ales of the larger end reaching to about the middle of the shaft, the smaller end is somewhat longer than in Lycopodina, of a similar structure, but elliptical in a trans- verse section: to the cliche may be added forcipes. 7. A. infundibulum Levins. PI. II, Figs. 20— 21. PI. XI, Fig. 9 a — m. 1874. Esperia cupressiformis Carter, partim, specimen in interclusione commemoratum, Ann. Mag. Nat. Hist. Ser.4, XIV, 215, PL XIV, fig. 19 a, b. 1885. Esperia bihamatifera Armauer Hansen, partim, the Norwegian North-Atlantic Exp. XIII, Spon- giada;, PI. Ill, fig. 6. 1887. Espcrclla infundibulum Levinsen, Dijmphna Togtets zool.-bot. Udbytte 366, 19, Tab. XXIX, Fig. 14, Tab. XXXI, Fig. 17—19. Formed like a calyx on a long stalk. The skeleton consists in the stalk of a spicula-axis. in the calyx-wall of less regularly arranged spicules; on the outside op the calyx spicules project. Spicula: Megasclera of three forms, styli or sitbtylostyli in the axis and the calyx-wall o-ij — o-Sj""". styli with a very long, fine point, projecting on the outside of the calyx 0-44 — cr6""", subtylostyli in the refolded edge of the calyx 0-141) — 0-22""": microsclera of huo forms, the characteristic anisochehe palmatie 0-018 — o-o2j""". forcipes o-oJs"1'". This species is formed like a calyx placed on a long, thin stalk. The calyx may be somewhat differently shaped; most frequently it has a regular form as a short funnel and with a wide round opening, but sometimes it is highly compressed, so that the two sides are closely joined, and the opening becomes a narrow slit. Of the specimens from the Iugolf-Expedition one is torn off, the other is attached to some sponge-spicules. From the Kara Sea we have it attached to tubes of Pecti- naria hyperborea. The largest specimen in hand (from the Kara Sea) is <~pmm high, of which the stalk makes iflmm\ the compressed calyx is ca. iomm in diameter. The stalk is very thin, 0-5— imm, a little thicker below than above. The smallest specimen is 14™™ high, and has a very small calyx of a dia- meter of only i,5mm. The edge of the calyx looks as if it was thickened, but this is owing to the fact that the edge is refolded, and the fold fits closely to the inside. The calyx is of a rather soft con- PORIFERA. II. 69 sistency, the stalk firm, but flexible. The colour (in spirit) is a dirty cream-colour. The surface, both of the stalk and of the outside of the calyx, is shaggy from projecting spicules. There is a thin dermal membrane, which on the outside of the calyx is pierced by the projecting spicules. Pores and oscula have not been seen with certainty; on the outside were seen scattered openings of different sizes, and in one specimen there were a few openings in the bottom of the calyx; but in both cases the question is possibly only of damagings of the soft tissue. The skeleton. The skeleton of the stalk consists of an axis of closely united needles parallel to each other, between which are interwoven other needles which jut out horizontally. Above the axis is divided more or less distinctly into fibres that pass into the skeleton of the calyx. In the calyx-wall the skeleton consists of needles which are not united into fibres, and a great part of which are placed chiefly in the longitudinal direction; they are not, however, parallel to each other, but inter- cross irregularly, and some are also found placed in other directions. Between these needles spicules and spicula-bundles are inserted on the outside, projecting through the surface and directed somewhat upwards; the inside of the calyx, on the other hand, is smooth without projecting spicules. In the upper part of the calyx-wall the spicules are closely packed and parallel to each other; in the refolded edge spicules are found of a special size, as will be more particularly mentioned below; moreover, this edge is highly filled with cheke. Spongin is found, at all events in the stalk. Spicula: a. Megasclera. These are styli or subtylostyli ; they fall under several forms which also occur in different places of the sponge, but on account of the slight material, I have had som€ difficulty in examining this fact. The skeleton of the stalk and the greater part of that of the calyx consists of long, slender styli, which have sometimes a small head-swelling. They are fusiform, taper- ing a little towards the head-end, and they have an evenly tapering, middle-long point Downward in the stalk they become shorter and also somewhat curved, and the spicules that are horizontally interwoven in the stalk and projecting are all short and curved. In most individuals these projecting, shorter, and a little curved needles deviate further by having a more or less distinct head, .so that they become tylostyli. Taken as a whole these styli vary from ca. 017 — 0*83'n,n, but in the calyx and the upper part of the stalk they do not generally go below ca.O,3mm; the thickness is 0-0057 <)'<1ii,"ra- Besides these styli, which form, accordingly, the principal part of the skeleton, still two other forms are found; the first of these are very slender styli. showing sometimes an almost imperceptible head- swelling; they are considerably finer than the preceding oiks, and they have a verj long, fine point, almost always with an even curve; their length is between <>-,|| o-6,nm; in their lower part the) slightly fusiform, and their thickness in the thickest part is at mostO'OO; "'. These spicules are found outermost in the calyx-wall and project from it; they seem mostly, but not exclusively, to form the projecting spicules. The third form of megascleres are short, straight tylostyli or subtylostyli; the head is tolerably well marked and placed a little below the rounded end, the point is short. Their length is 0-149 -if microsclera anisochelse 0-0.27""" long, and forcipes 0-076""" long1). A. minuta Lainbe might, as to its exterior, remind of infundibulum, but its spiculation is differ- ent. According to Lambe the megaselera are of two kinds, styli or subtylostyli 0-327 — o-543mm long and 0006 — croo8mm thick which form the principal part of the skeleton, and small tylostyli 0-196 — 0-294""" long and 0-005 — o-oo6mm thick which project from the surface. The microsclera are auisochelas o-oi8 — 0-019""" long, which, to judge from the figure, may be said with certainty to belong to the Cotylzna-type. The genus Asbcstopluiiia, consequently, is chiefly characterized by its erect symmetrical form with the skeletal structure contingent upon this form, and by the occurrence of a small chela of peculiar type. As will have been seen in the preceding, it is, however, with regard to both these features, divided into three groups, and to this division contributes further the occurrence in one of these groups of sigmata and of a stalk-coating with special spicules. The subgenus Asbcstopluiiia s. str., formed for the first of these three groups, is accordingly characterized as to its form by distinct, often rather long, well separated lateral branches, by a small chela, the larger alas of which reach far down towards the smaller end, which latter is narrow, and by the occurrence of sigmata and of a stalk- coating with a spiculation of finely spinulous tylostyli or tylostrongyla. On the other hand, the occur- rence of the large chela cannot be used, as this chela is wanting in two of the species. The second subgenus, Lycopodina, is characterized by its often shorter, sometimes less well separated branches, which also sometimes all issue from the top of the stalk, and by a small chela, the larger ala? of which pass quite down to the opposite end of the chela, which end is broad and of a peculiar form. Sigmata and stalk-coating are not found. The occurrence of forcipes cannot be used, as these spicules partly are wanting in one species, and partly may be found in the third subgenus. This third sub- genus, Cotyliiia, is well characterized by its form, which is as a calyx (or a head) on a stalk; it has a small chela, the larger alas of which pass to about the middle of the shaft, the smaller end of the chela is constructed about as in the preceding subgenus, showing, however, characteristic differences, and a transverse section of it shows an elliptic contour. Sigmata and stalk-coating are not found, but forcipes occur in two of the species. Thus the two first subgenera are especially separated by the form of the chela, and by having or wanting sigmata and stalk-coating, the two last genera by the form of the chela and by the outer form of the sponge. Whether the peculiar, long pointed, pro- jecting spicules occurring in two of the described species of the subgenus Cotylina may possibly prove to be characteristic of the genus, cannot yet be decided. According to the account rendered in the preceding of the species that have not been fully treated here, all the known Asbestoplu w«-species mav, as far as the fact can be decided from the lite- rature, be grouped in the following way in the established three subgenera: ') In Topsent's work from 1904, which I have received later, the author himself draws the attention to the fact that versati/is is to be referred here. PORIFERA. II. Asbestopluma s. str. pennatula O. S. rialis R. and I). bihamatifcra Cart. Belgica Tops. furcata mihi. Lycopodina n. cuprcssiformis Cart, occidentals Lambe lycopodium Levins. hydra mihi. Cotylina n. infundibuhc?n Levins. comata mihi vcrsatilts Tops. inii/ttfa Lambe. A systematic survey of all ^j^\5-/fi>//W the genus. ciila: Megasclera styli o'jp — uyj""": microsclera oj three /onus, anisancorm unguiferce with five teeth 0-021 — irojj'""\ sigmata of two forms, large ones o-oj8 o'/o""", small ones with compressed end parts CTOfO 0-0-/.2""". Of this species I have had only a slight material, and I therefore am only able to add little new to the very good and exhaustive description given by Sars. Of the specimens in hand the largest ones agree, as to their external form, with the description of Sars. They consist of a stalk, divided below into a great number of branches or fibres, so that a richly branched root is formed; to this root -., m< bottom-material is still attached, anion;; oilier things tubes of Rhabdamviina. The stalk is straight and from it go off lateral branches issuing at about right angles, only directed a little upwards. The lateral branches may be of different lengths, but generally they are longest below. The distance between them is different. The branches may be directed to different sides, but upon the whole a certain bilaterality is prevailing. Besides the branched specimens we have a couple oi smaller ones consisting only of a central stem without branches, but otherwise of the same structure. From the stalk and branches branchlets or filiform appendages issue everywhere and on all sides. The\ are thin, thickest at the base, and tapering a little outward; they may be of somewhat varying length, but reach at most a length of ca. 3"""- The branchlets are directed upwards in ,1 somewhat arcuate way. At the point of the stalk and the branches they become short, and at the outermost c]\<\ they are placed close together as quite small projections, whereby the stalk and branches here show a little So I'ORIKKRA. II. swelling, as described and figured by Sars. Sars says that the branchlets are generally arranged in a circular way, ray material is too much damaged to enable me to decide this fact with certainty. The largest of in\ specimens is, inclusive of the root, 75mm high, but the specimen is not quite entire above; the longest branch is 25""", and the thickness of the stalk is fully 2mm. The small unbranched specimens are 33""" high. Thus this species would seem not to reach any considerable size; Sars gives the height of his specimen to 6oml", and the specimens from the North .Sea and the Gulf of St. Lawrence, mentioned by Schmidt and Lambe I.e., were smaller')- The colour of the sponge '(in spirit) is white or slightly yellowish, often a little transparent; Sars states the colour in fresh speci- mens to be transparently yellow'. On account of the axial skeleton the sponge is rather stiff and not very flexible; the outer layer of tissue is soft, and the branchlets are flexible. The surface is smooth, and only at the end of the branchlets projects the supporting fibre. No distinct dermal membrane was seen. Pores were not observed with certainty; here and there on the surface small circular nings were seen, but on account of the bad state of the material I dare not with certainty regard them as pores. Oscula were not found either. Nor have, as it is well known, pores and oscula been mentioned before in this sponge2). The skeleton consists, in the stalk and the branches, of a compact, polyspicular axis, the needles of which are parallel to each other and to the longitudinal direction; the axis of the stalk, however, is in the lower part somewhat spirally twisted. Below, the stalk, as mentioned, ends in a highly branched root, the branches of which taper more and more, till they end almost with only one spicule, or with a couple of spicules alongside each other. The branches on the stem are not inserted in the axis in the same way, as are the branchlets; it may rather be said that a cleaving takes place, some spicules by degrees bending to the side and forming the branch; in the angle between the stalk and the branches some spicules are found running evenly arcuately between the stalk and the branch, so that the angle is not seen sharply, but as a rounded curve. The skeleton of the branchlets is formed by a fibre pas- sing through the branchlet to its end. It decreases in thickness outward, and accordingly it has here few er spicules than farther in, most frequentlv it has here only a couple of spicules alongside. The fibres of the branchlets are inserted in the spicula-axis of the stalk or the branches, between the spicules of these axes, and the}' pass in to the centre, where, when several branchlets are placed at the same height, they meet. The part of the fibres of the branchlets that is inserted in the axis, is in ■I Wyville Thomson states (The Depths of the Sea, 112), in a general and, otherwise, somewhat vague mention of ( YadorAiza-sptcies or C/at/or/iicaAikc forms, that thev may reach to an extent of 50 — So^m. He says that at least three species occurred. It is not possible to decide, which species his statement refers to, but I suppose it is to the following ones C. abyssicola is surely not among them, and we see also that the stations mentioned by Carter (Ann. Mag. Nat. Hist. Ser. 4, XVIII, 319. at which Cladorhiza-iorvas were taken, have, all of them, negative bottom temperatures, while abyssico/a occurs on bottoms with positive temperatures. -1 Ridley and Dendy iChalleng. Report, 87) say, under the species mentioned by them as C. abyssicola var. rect- angularis: The anatomy of the soft parts of this remarkable species has always been a mystery . I do not see that this is to be said especially of this species. That pores, oscula, and canal-system have not been described is a fact that holds good of many sponge-species, and especially with regard to this sponge Sars has given several details beyond what is known of many other species. When he says that in the layer of tissue absolutely no canals or cavities can be discerned , this of course, is only the expression of the fact that he has not seen them; in the comparatively thin layer of tissue, the canals, 110 doubt, are small, and scarcely to be observed without special preparation. Ridley and Dendy have not been able to examine their specimen i which otherwise assuredly does not belong to this species) anatomically, as their material was dried, but they have not taken the opportunity either of examining anatomically any of the other Clariorliiza-species they have described. PORIFERA. II 8] the common way spread in a fan-shaped manner in the longitudinal direction, so that in a transv section it appears to have onh the thickness of a couple of spicules. Accordingh the fibre.- pass from the middle of the axis through the layer of tissue surrounding the axis, and through the branchlet to its point. In the layer of tissue coating the stalk and the branches, as far as 1 have been able to see, only rather few, scattered spicules are found. In the stalk and the branches the spicules are cemented by a clear mass of spongin; it coats, no doubt, the whole fibre with a thin layei ol .spongin, but forms no visible sheath. In the lower part of the stalk it may become somewhat more copious, and then the otherwise white, transparent axis becomes here a little yellowish. In the branchlets no spongin was observed. Spicula: a. Megasclera are styli; they are straight or quite slightly curved: they are Eusiforra, tapering more or less towards the head-end; not rarely their outer part has a special, but slight taper- ing. The opposite end tapers evenly; the point proper may be somewhat varying, but is always short or rather short, not rarely quite blunt or rounded. The spicules of the axis and the branchlets are of the same form and cannot be said to fall under two distinct groups, but upon the whole there is, however, some difference as to size between them, so that the axial spicules are averagel) lai than those of the branchlets. The length of the axial spicules is about 0-5 — 073'"'", and the thickness from 0-013 — o-oic)mm. The spicules of the branchlets are generally 0-39— o\i7""" long and 0-007— ca. Q.Qj^mm thick. All kinds of transitional forms occur however. Thus upon the whole a variation is found in the spicules as to length from 0-30) — 073 'nin and as to thickness from 0*007 o-oig""". Besides by their size the styli of the branchlets deviate also from those of the axis by having a Ion point, and moreover they show also a little curve at the head-end, about as figured and described by Sars. Sars says that such spicules only occur at the point of the branches; thefactis, however, that they form the fibres of the branchlets, and accordingh' they are also found in the points of the branches, where the branchlets are close together; the mentioned curve may otherwise also be found in axial styli. b. Microsclera; three forms occur, anisancorse unguiferse and sigmata of two forms and sizes. 1. The ancorae are of the structure typical of Cladorhiza with a regularly curved shaft and five distinct, narrow, lanceolate teeth in either end; a considerable difference is found between the sizes of the two ends. The larger end has on either side of the shaft a narrow ala somewhat longer than the teeth. A sure view of the number and form of the teeth is onh to be obtained by regarding the ancorse from the end. Sars, in the work quoted, says that the ancorae have three teeth, but that some have five, and continues: Whether this applies to all or only to some the position of which happened to be more favorable, I am not aide with certainty to decide '1. The real fact is that the ancorae have always five teeth in either end. Tin size of the ancorae is only little varying, their length from 0-021- 1 ■•■ , and the thickness of the shaft is ca. ooo2min. A few developmental forms of the ancorae were also seen, in the finest ones the ends are as yet onh I developed, and they are equal or about so, but a difference in size appears ver) soon. 2. Thi sigmata have a regular sigma-form; the} are always plane 01 about plain. Theii length is between 1 11 is evident that the opinion of Sars i- that the ancorae, what he lias not been able t<> decide with certainty, may possibly always have- five teeth, but that thi ""1\ t" be seen, when the ancora: are favoural expressii.il, t.> lie sure. s:hs reallj something different Tin- [ngolf-E xpedition. \ I PORIFERA. II. i ■ r,m, and the thickness is proportionately 0-005 — o-oo6mni. 3. The small sigmata are peculiar form not mentioned by Sars, about as the form known from sigmata in some of the Asbesto/>hima-species, but here much more sharply marked. Either end of the sigma from the middle and to the point of the recurved part is highly compressed and inwardly sharpened in an edge-like manner. The sigma is contort, and almost always rather exactly one fourth of a turning. The length is 0-040— 0-042""" and the thickness in the middle ca. o-ooi5",m. The small sigmata, as stated by Sars, occur in the points of the branches in somewhat greater numbers, but besides they occur also in other places of the tissue, but only in very small numbers. The large sigma is stated by Sars to occur scattered in the tissue, and in greater numbers in the points of the branches; this statement I have not found corroborated, but have found this sigma occurring equally frequently everywhere in the tissue, but not especially copiously. The ancorse are present in great abundance, partly throughout the tissue, and especially in the skin or the outer layer; thus they are seen very abundantly in the thin layer of tissue on the branchlets. Embryos. Embryos were found scattered in the tissue in rather great numbers. They are globular and reach a size of ca. o-35nun in diameter. They contain no spicules. According to Sars the embryos seem to be developed in the ends of the branches; this fact I did not find corroborated by my material; later, at all events, they are found everywhere in the tissue in great numbers, as has ■ been observed by Sars. They were also found in the small, unbranched specimens. Remarks: A sure determination of this species is no easy thing, as it is very closely allied to the succeeding ones, and has also constantly been confounded with them. I was long in doubt whether the present species and the following one were specifically different; there are, however, constant char- acters, especially in the size of the spicides, and it was found, moreover, that C. abyssicola occurs only on bottom with positive temperature, while the following species is a native of the cold area. I have not -.ecu Sars's type specimen, but a specimen sent by Dr. Nordgaard, obtained on Sars's old locality, Skraaven, agreed exactly as well with the description by Sars as with my specimens. The species mentioned by Wyville Thomson in The Depths of the Sea , and by Carter in his work on the Porcupine -sponges as C. abyssicola belong surely, as already mentioned, to some of the succeeding species. With regard to the C. abyssicola mentioned by Armauer Hansen in The Norwegian North- Atlantic Exp. XIII, the fact is most probably that he has not had this species before him at all; all the figures of the exterior show on the contrary that he has had the four following species, gelida, tenuisigma, corticocancellata, and oxeata, and those of the spicula-figures that can be interpreted at all show also that the question is not of abyssicola. I have examined two of his specimens which belonged respectively to the two following species, gelida and oxeata. All the enumerated localities are also seen to be situated in the cold area, with only one exception, and this one is found at the very border of this area. Of the C. abyssicola mentioned by Fristedt (Vega-Exp. vetensk. Iaktt. IV, 455) I have examined one specimen which proved to be C. oxeata. The specimen mentioned by I.ambe I.e., on the other hand, is no doubt C. abyssicola, as is obvious from the description; when Lambe says that the ancorce seem only to have three teeth in either end, this is no doubt only owing to the fact that he has not seen them from the end. Finally it must be noted that the two forms mentioned by Ridley and Dendy, C. abyssicola var. rectangularis with styli up to 2mm long, PORIFERA. II 83 and C. abyssicola var. linearis, with three-toothed ancorse (.032""" long, may be said with certaint) not to belong here, but they must be independent species. Locality: The Ingolf-Expedition has only obtained a slight material of this species; station 32, the Davis Strait, 66° 35' Lat. X., 56" 38' Long. W., depth 318 fathoms (bottom temperature 3 9C), the two largest specimens; station 40, south of Iceland, 62 00' Lat. N., 21 36' Long. W., depth 845 fathoms (bottom temperature £$ C), two small, unbranched specimens. Geogr. distr. Skraaven at the Lofoten, depth 300 fathoms (Sars), and depth ca. 200 fathom- lone specimen sent by Dr. Nordgaard); the Saltenfjord, depth ca. 185 fathoms (Dr. Nfordgaard); the Skager Rack, depth 294 fathoms (O. Schmidt I.e.); between Franz-Josef Land and NovaZembla 79 Lat. N., 590 14' Long. E., depth ca. 130 fathoms (v. Marenzeller I.e.); the Gulf of St. Lawrence, depth fathoms (Lambe I.e.). Thus the species is known distributed from ca. 6oc Long. W. to ca. 60 Long 1. and between 60 and So Lat. X. It does not go to specially great depths, the bathymetrical range being between 130 and S45 fathoms, and it is exclusively a native of a bottom with positive tempera- ture. On all the localities the species was taken on muddy bottom, and its richly branched root agrees also with this fact. 2. C. gelida n. sp. PL III, Fig. 1. PI. XII, Fig. x a— h. 18S5. } Cladorhiza abyssicola Armauer Hansen, The Norwegian North-Atlantic Exp. XIII. Spongiadse, partim, PL VII, figs. 7 b, 10, 12. Slender, with branches issuing from a central axis; the branches arranged more or less distinctly 111 a plan or issuing quite irregularly: often very long and subdivided. The stem ending belozv either in a root or a little basal expansion. The skeleton oj the type oj tin genus. Spicula: Megasclera styli >rjo — o-yjmm; microsclcra of /free /onus, auisaueone ungtiifera- with live teeth 0-028 — ■ojf"", sigmata oj two /onus, large ones o-i2—o-i6mm, small ones, loith compressed terminal parts 0-044 — o-oj/""". Of this species we have a rather considerable material, but most of the specimens are rather much damaged. The species is chiefly of the same form and structure as C. abyssicola, but it grows to a considerably greater size, and is more irregular. It consists of a stem, from which lateral branches of varying length issue. The original principle seems to be that the branches issue in one plan to two opposite sides; but this principle is not carried through, and so the branches are frequently arran< irregularly and issue to more sides; the arrangement in one plan, however, is most frequently ri ible. The distance between the branches may be somewhat varying. The} issue generalh at about right angles, only a little directed upwards. Sometimes the branches are a little swollen toward.-- the end, but often, however, such a swelling is not found. To judge from the material in hand, the stem may end below in different ways, either in the same wa\ as in abyssicola with a branched root, 01 with a little expansion which then has been attached; this feature is probabh to some degree dependent on the bottom. While in the form now described the sponge is tolerably regular, a high degree of irregularity is very frequent. This irregularit) maj be owing to several causes. Thus the stem, which in the r regular forms is tolerably erect, may become sometimes irregularh curved, sometimes twisted in such a way, that the branches an. lying in all plans. Then the branches may also be bent in mam diffei N POR1FERA. II. ways and be of very different lengths, and while in the more regular forms they are most frequently unbranched, they may here be subdivided. Finally anastomoses and coalescences may take place between the branches in the most irregular way, so that the whole thing gets a quite confused appear- ance; nay, even branches from different individuals seem to be able to coalesce. When such anasto- moses takes place, it is always the spicula-axes of the stem and the branches, which touch each other and are coalesced, and the fact is evidently owing to the presence of sponging. The stem and the branches are set with branchlets or filiform appendages. They issue rather closely to all sides, and no definite arrangement is to be seen. They are frequently directed somewhat upward or on the branches somewhat towards the point, and in different individuals they may be of somewhat different length. With regard to the size to which the sponge may grow it is impossible to say anything definite on the basis of the material in hand, as all the specimens are fragments more or less. In one of the largest fragments the stem has a height of ca. nomm; another specimen measures, on account of the verv long branches, ca. 150"""; one of the most irregular fragments, in which stem and branches could no longer be distinguished, has a greatest extent of 230mm. The length of the branches, as men- tioned, may vary very much. The stems and branches are of about equal thickness, the maximum of which may be given to ca. 5mm, but it may be somewhat less. The branchlets or the filiform appendages are thin, filiform, and a little tapering outward; their length may be somewhat varying, the maximum is 5 — 6mm, and the thickness at the base does not exceed o'5mm. In a few cases branchlets may be found as only exceedingly short, conical projections. On account of the firm axial skeleton the consistency of the sponge is hard, but, especially in the upper parts, somewhat flexible; the outer layer is soft, and the branchlets, in spite of the fibre in them, are soft and flexible. The colour (in spirit) is white to yellowish white. The surface is smooth, spicules project only at the ends of the branchlets. An inwardly distinctly bounded and consequently easily separable dermal membrane is not found; on the other hand the whole layer of tissue is easily separated from the axis. Oscula and port w I have not been able to find, and therefore I take them to be closed. In the layer of tissue nothing is seen of the canal system under slight magnifying powers, but the tissue is apparently of uniform structure, the canals being very small. It is only in thin sections and under higher magnifying powers, that the canals are seen. The skeleton is constructed as in the preceding species, and consists in the stems and branches of a very strong polyspicular axis; the needles of this axis are closely united and connected by spongin. They are chiefly parallel to each other and to the longitudinal axis, the axis, however, is most fre- quently more or less spirally twisted, often so much, that the direction of the needles deviates con- siderably from the longitudinal one. Also in the superficial part of the axis the needles are often not quite parallelly arranged, but may intercross, owing to the fibres of the branchlets being inserted between them. The needles of the axis are turned in different ways, now the point is turned upward, now downward. As in the preceding species the branches are formed by a number of spicules bending to the side, and, at all events, only the middlemost spicules of the branches reach in towards the middle ■1 Such irregular anastomoses (at all events in the same individual) seem to be frequent in the C/ador/iiza-species, they will thus be mentioned again in the following species. It seems also to be this same feature, which is found tlu- specimen of the socalled C. abyssicola var. linearis, figured bv Ridlev and Dendv (Challeng. Report, Monaxonida, PI. XX, fig. 6. PORIFERA. II 85 of the axis. The central part of tire axis may be somewhat looser, or a little cavity may be found here. The skeleton of the branchlets is formed by a fibre running through the middle of the branchlet; the fibre tapers outward, and has fewest spicules at the outei end. When tin- branchlets are short, the fibre seems to become thicker and have more spicules. The fibres of the branchlets are in the common way inserted in the spicula-axes of the stem and the branches, between the spicules of these axes; they reach to the middle of the axis, and are spread in the longitudinal direction in a tan-shaped way. In the layer of tissue, which coats the axis, and may be of somewhat varying thickness, only rather few, scattered spicules are found. In the stems and branches the needles are connected by a mass of spongin forming, however, no sheath; under the microscope it appears white and clear, but yet it gives to the axis a yellowish, hyaline appearance. The stem has most spongin and is, consequently, most yellowish at the base. In the fibres of the branchlets spon- gin was not observed. Spicula : a. Megasclcra are styli, straight or quite slightly curved; they are more or less fusi- form, but most frequently slightly so, only tapering a little towards the head-end; the point is some- what varying, from short, some- times somewhat blunt, to middle long. Their length varies from 0-40— o-jj1""1 and the thickness Fig. 2. Cla ' gelida 11. sp. Transverse section. The branchlets being directed alittle upward, the fibres issuing from tin- centre are only seen .1 little way out in the tissue, where they are then cut awav, while the fibres seen in tlu- branchlets issue more downward, so that their bases are not seen. In the tissue emb] ca. 32. about from o-022min down tocroi 1 """. The spicules are upon the whole- larger and specially thicker in the axis than in the branchlets, but the) cannot Ik- said to form two groups. The styli of the branchlets have also a somewhat longer point. Otherwise the length and thickness arc in no proportion to each other, and styli are rather frequently found in the axis of tlu- smallest length, but of the greatest, or about the greatest thickness, while on the other hand long styli ma\ be consider- ably fine. In the branchlets and the layer of tissue spicules may be found tli.u are considerably finer than the others and must be developmental forms, they are long pointed. Among tlu styli, especially in the branchlets, irregular forms are often seen; thus, but more rarely, oxea; more frequently forms are seen with one or more swellings, b. Microsclcra; three forms are found, anisancorae unguiferae and sigmata of two forms and sizes. 1. The ancorae are oi thi typical Clad r/w'-a-structure, and have five distinct, lanceolate teeth in either end; one end is considerably larger than the other. The larger end has on either side of the shaft a narrow ala a little longei than the teeth, but comparatively 86 PORIFKKA. II. somewhat shorter than in abyssicola. The size of the ancora; varies between 0-028— 0-034""", by far the most frequent size is o-c^i""", the thickness in the middle of the shaft is ea. o-oo3'"m. Developmental forms of the ancorae occur frequently in all stages, clown to extremely fine ones, which are of about the same length as the full)7 developed ones; in the very youngest stages both ends are as yet equal1). These youngest stages show in either end apparently only a hook-like recurving (PI. XII, fig. 3 d) which must, accordingly, be taken to correspond to the median tooth; but they are so fine and transparent, that the real form of the end cannot be seen with certainty; in the stages a little older the teeth are seen. 2. The large sigmata are of a regular sigma-shape, they are plane, or only slightly contort. Their outer part, the recurving and the hook, is not quite cylindrical, but somewhat compressed. They vary in length from o-i2— o-i6m"\ and in thickness from 0-006 — o-ooc)mt". Developmental forms in different stages of these sigmata were not rarely seen; the younger of these are more or less fine, evenly curved, and long pointed staves without recurved ends; the ends are only developed by and by. Also the develop- mental stages show the compression of the ends, and these are sharp inward. 3. The small sigmata are of the same peculiar form as in abyssicola, with compressed ends, inwardly sharpened as edges. They are likewise always contort to one fourth of a turning. Their length is 0-044— o-05im'", an<^ ^ie thickness in the middle is ca. o-ooi5mm. The occurrence of this sigma is peculiar. It occurs always only very sparsely, so that pieces of the sponge may be examined without any being found; but sometimes this form of sigma seems to be quite wanting; thus in some specimens I have examined a great number of pieces without being able to find it. Otherwise it is found sparsely in the tissue without any such definite occurrence as in abyssicola. Neither does the large sigma occur in great numbers, but consi- derably more copiously than the small one; it occurs in the layer of tissue and especially in the skin. The aneorce are present in exceedingly great numbers, partly throughout the layer of tissue, but especially in the skin or the outermost layer; they are especially closely packed in the thin layer of tissue on the branchlets. Embryos. Round in the tissue embryos were found ; they lie singly in the layer of tissue between the axis and the surface. They are all but globular and of an average size of ca. 0-3""". No spicules were found in the specimens examined. This species, as will have been seen, is very closely allied to abyssicola, and it is mainly sepa- rated from it by the constant difference in size of the three forms of microsclera. As mentioned under the preceding species, I have seen a specimen from the material of The Norwegian North-Atlantic Expedition of the species mentioned there by Armauer Hansen as C. abyssicola. It was a small fragment, very much damaged, but it seems doubtless to belong to the present species. The size of the ancorae is generally 0-028""", and that of the small sigmata o-044mm. The specimen was from station 31 with a bottom temperature of -^i°oC. Of the figures of the exterior in The Norwegian North- Atlantic Expedition PL VII, figs. 7 b, 10, and 12 would seem to belong to the present species. An >) Carter, as is well known, advanced the theory that the anisochelae in their development pass through an iso- late stage, because in a feu species he had found large anisochelae and small isochete together. He got this view on nit of his erroneous interpretation of the growth of the chelae. The fact that forms as the anisancone of the Cladorhiza gin with a stage where both ends are equal cannot, of course, corroborate Carter's theory, as his opinion was that an isochelate stage fully developed as to form preceded the fiual, anisochelate one. PORIKKRA. II. attempt to interpret the given spicula-figures, would, I suppose, show figs. 3, 7,8, 9, 11, and 12 on PI. IV to belong to the present species, hut the interpretation is doubtful. Locality: The Ingolf, station ri2, 67 57' Lat N., 6 44' Long. W, depth 1207 fathoms (bottom temperature -f i°i C.|; station 113, 690 31' Lat. N., 7 06' Long. W., depth [309 fathoms (bottom temp ture -M°oC); and at 60 To/ Lat. N., 5°39'Long. E., depth 620 fathoms (bottom temperature ca. : (Ad. Jensen, the eruise of the Michael Sars 1902). The two first localities are situated in the Nor- wegian vSea about between Jan Mayen and Iceland, the last one 111 the Faroe Channel. Geogr. distr. Besides on the mentioned localities, the species, as before mentioned, has been taken by the Norwegian North-Atlantic Expedition at station 31, 63 10' Lat N., 5 00' Long. E., depth J17 fathoms. Presumably it has been taken at more places by this expedition, but, at all events, always in the cold area. Accordingly the species is known from the Norwegian Sea and from the Faroe Channel with a bathymetrical range from 417—1309 fathoms, and it occurs only on cold bottom. I suppose that the species is also found among- the Cladorhiza-iorms from the Faroe Channel mentioi by Wyville Thomson in the Depths of the Sea 112 — 113. 3. C. tenuisigma n. sp. PL III, Figs. 2—5. PL XII, Fig. 4 a— e. [885. ICladorhiza abyssicola Armauer Hansen, The Norwegian North-Atlantic Exp., XIII, Spongiadse, partim, PL IV, fig. 14, PL VII, fig. it. Slender, with branches issuing from a central stem, the branches 'tcnest distinctly in one plan to two sides, most frequently tang and ending in a swelling. The branchlcts more or less distinctly arranged in a ring-like manner. The stem ending below in a richly branched root. The skeleton oj the generic type. Spictila: Megasclcra styli o-j with five teeth 0-024— o' 028""", sigmata of two forms, tine ones of the common form o-ojS — 0-048""", sig- mata with compressed terminal parts 0-048—0-056""". In the exterior and skeletal structure this species is very similar to the preceding one, but it is distinguished by characteristic differences as well in the exterior as in the spiculation. It is formed of an erect stem ending below in a densely and richly branched root In the specimens in hand that are possessed of the root it is formed in such a way, that the stem continues quite down to the lowei part of the root, and only here is divided into branches, while from the lower pari oi the stem thicker close-set branches continually pass of, and again subdivide to a high degree. The finest branches end with the thickness of one spicule. In the specimens in hand the radical branches issue only to one side, that the whole radical tuft is turned to that side (PL III, fig. 3). To the radical branches, especially their outer part,' some bottom material, as pebbles and especially Foraminifera 111 gnat numbers, is attached. These bodies stick rather Eirmly, and seem to be kept by the spongin present in the 1 Lateral branches issue in the common way from the stem. These branches issue with varying in and may in this respect issue in .1 rather irregular manner; sometimes, however, they are placed in a tole- rably regular way. They go off at about a right angle or are a little directed upward. The blanches in.n be of varying length, but generally they are very long. In a few cast- the branches may again carry l'ORIKEKA. II. ie short branches, and irregularities caused by anastomoses and coalescing of branches may occur, but both these features seem to be found only rarely. The branches are generally arranged in a distinctly bilateral way, but here and there a branch may be placed in a different plan. The bilaterality is effaced in only one specimen, in which the branches are very close-set, but this specimen is upon the win ile somewhat irregular. As in the preceding species, stems and branches carry brauchlets. These branchlets are in this species more close-set than in the preceding one, and besides they are here arranged more or less distinctly in a ring-like way. This arrangement is not always marked, but is in all cases recognizable; sometimes the circles pass into each other, and then there is a beginning spiral arrangement. The number of the branchlets in the circle is generally some half-score. The brauchlets pass off at right angles, or are, especially in the outer part of the branch, directed towards the point of the branch. Their length may be somewhat varying, from rather long, outwardly thread- fine ones, and to quite short, comparatively thick projections. The branchlets of the same circle are move or less coalesced at the base, and when they are quite short the branches get a peculiar jointed appearance, and may to some degree remind of the arm of an Ophiurid. In a few places of the stem or the branches the brauchlets may be quite wanting, and these parts are then slightly shaggy. The branches end at the point in a globular or ovate swelling, below which the branches are a little con- stricted, by which means the swelling becomes more sharply marked off. The last brauchlets before the swelling decrease a little in length. One of the tolerably whole specimens, which is, however, not quite undamaged above, has a height of ca. 170™™, and most of the other specimens seem to have been of a somewhat similar height. The specimen which seems to have been the largest one is only a little higher, but it is broken off below, and a rather large piece is no doubt wanting. The length of the branches may, as mentioned, be somewhat varying, the greatest length measured was 80 — 90""". The stem and the branches mav be of somewhat varying thickness, but thev are generally compara- tively thin in proportion to their length, and so the species gets a more slender appearance than the preceding one; the thickness, which is about equal in stem and branches, or only a little greater in the stem, may be given to 2 — 5mm. The branchlets vary from quite short projections to 8mm long, threadfine appendages. The consistency is as in the preceding species. The colour (in spirit) is whitish to whitish yellow. The surface is upon the whole smooth; at the points of the branchlets the fibres project, and the terminal swelling of the branches as well as the parts of the branches that show- no branchlets are slightly shaggy. Outermost a very thin dermal membrane is found, only distinct in the parts between the branchlets; it is supported by spicules underneath, but cannot be separated alone. Pores are found in the dermal membrane, especially in the parts between the branchlets; they are often very close-set. They were measured from quite fine openings to a diameter of ca. o-o6mm. Pores are also found in the swollen terminal part of the branches1)- Oscala have not been observed. In transverse sections of the sponge canals are seen in the layer of tissue between the fibres of the branchlets; these canals run chiefly as longitudinal ones, and being the widest canals seen it is an 1 Ii pores have not hitherto been mentioned in the C/adorfa'sa-species, I suppose that it is only owing to the fact that they are only to be seen with difficulty. The fact is that the outermost layer consists of close-lying membrane-like parts rated by narrow cavities; the outermost membrane forms the dermal membrane. The pores in this membrane, accord- ingly, lead into a cavity inside, and the cavities are connected with each other by pores in the membranes. Now the der- mal membrane proper cannot be separated except by special preparation, and if we cut off a piece of skin-layer ever so thin, we shall nevertheless get more than the outermost membrane, and so the pores are not seen by transmitted light. PORIFERA. II. obvious conclusion that they are excurrent canals; if so, we should expect to find oscula at the points of the brandies. It may, however, also be possible that among the mentioned pores some may a. incurring openings, others as excurrent ones. The skeleton is chiefly constructed as in the preceding species. It consists in stein and branches of a powerful axis which is also here somewhat spirally twisted, especially in its lower part. The lateral branches are formed in the common wax. The skeleton of the branchlets is formed by a fibre more or less long according to the length of the branchlets; in the long branchlets the fibres are out- wardly very fine, and outermost they have only quite few spicules. The fibres of the branchlets are- inserted in the axis in the common way. As the branchlets are arranged more or less circularly, I fibres, in a transverse section passing through a circle of branchlets, are- all seen to go to the middle of the axis like the spokes of a wheel. When the layer of tissue with the branchlets and their fibres is removed, so that only the axis is left, this is seen to be transversely striated on account of the circular arrangement of the branchlets, the part of their fibres that is inserted in the axis appearing as darker circles when the other part is removed. The axes of the branches continue through the middle of the swollen terminal part, and at the outer end they spread in a somewhat penicillate way. From the part of the axis running through the terminal knob rather regular, thin fibres issue to the surface, through which their outer ends project quite slightly (Woodcut fig. 3). Thus the whole terminal knob may be regarded as a collection of coalesced branchlets. Between the mentioned fibres in the terminal knob arc- moreover found some scattered spicules. In the above mentioned places of the stem and the branches where no branchlets are found, fibres are nevertheless found as in the other places, inserted in the axis in the same way, and these fibres continue into the laver of tissue, which is, besides, highly filled with spicules some of which are running chiefly longitudinally, while most of them are situated irregularly. Some of these spicules project a little through the surface. In these places the layer coating the axis is of greater thickness, so that it may more likely be regarded, as if the 1". .inch- lets were coalesced to one layer. In the layer of tissue which coats the other part of the axis, are found rather copiously of which some are running longitudinally, while a great part are irregul scattered; the dermal membrane is supported by the outermost ones of these spicules. Where the branchlets are long there are the fewest spicules in the layer of tissue; the shorter the branchlets the more spicules are found in the layer of tissue, and the greatest number of spicules are found where the branchlets are quite wanting. In the stems and branches the needles ol the axes are cemented by a clear mass of spongin, giving to the axes .1 slightly yellowish colour. Spicula: a. Megasclera are styli, straight or almost straight; the) are fusiform, tapering evenly towards tin- rounded end, and towards the point to about the same degree; then-fore the point itself is short, but it may be more or less blunt and is sometimes rounded. There is no distinct difference Tin- [ngolf-f upeililion I\ i igma 11. sp. Longitudinal section tli end-swelling of a branch showing lllL- Si < IO. PORIFERA. II. between the styli of the axis and those of the branchlets and the layer of tissue, the styli of the axis being only upon the whole a little longer and especially a little thicker. With regard to the length styli may be found in the branchlets as long as the longest ones in the axis, but upon the whole they are shorter, and styli may be found here considerably shorter than are generally found in the axis; also are the styli of the branchlets almost always longer pointed. The length varies at most from ca. 0-58 — roimm, and the thickness from ca. 0-014— o-0257mm. With regard to the axial styli the length rarely goes below 070""", and the greatest thickness attained by the styli of the branchlets is ca. 0'02imm. In the branchlets long, fine styli with long points occur rather frequently, which are, no doubt, developmental forms, b. Microsclcra are anisancorse unguiferae with five teeth and sigmata of two forms. 1. The ancorse are of the common Ciador//iza-type, and are constructed quite as in the preceding species. Their length is 0-024 — 0-028™™, and the thickness of the shaft in the middle 0'002Smm or a little less. Developmental forms in different stages are rather frequent. 2. Sigmata of the first form are fine, of the common sigma-form; they have a somewhat curved -haft and regularly round-curved ends; they are contort up to the fourth part of a turning, most fre- quently, however, somewhat less. They have not the edge-like expansion occurring in the other form oi sigma, but are not, otherwise, quite cylindric, but seem to be somewhat compressed through their whole length. Their length is 0-038— o,048mm, and the thickness about o-ooi4mm. 3. Sigmata of the second form have a similar form as, and correspond to, the smaller sigmata of the two preceding species; they have an almost straight shaft, and their ends are somewhat compressed, but to a far smaller degree than in the preceding species. They are contort and always one fourth, or about one fourth, part of a turning. Their length is 0-048— o-056mm, most frequently nearest to the smaller size. The thickness is about o-oo25mm. The two forms of sigmata are easily distinguished; the former is especially distinguished from the latter by being finer and having no expansions towards the ends, by its curved shaft, and by its being generally twisted less than one fourth of a turning. It can only be confounded with developmental forms of the second kind. The two forms occur in distinctly limited parts of the sponge; sigmata of the first form occur in the tissue of the whole sponge, except in the end-knobs; in these, on the other hand, sigmata of the second form are exclusively found, and in copious numbers; but none of the sigma-forms occur in anything like the number of the ancorse, which are present in great abundance throughout the tissue, especially in the dermal layer. Embryos. Embryos were found in most specimens of this sponge. They are lying in the tissue outside the axis, often rather closely, but each in a cavity of its own, and each embryo is surrounded by a membrane. They are globular or somewhat oval, and of a diameter of up to o-5m!°. The spicu- lation is different in the different stages; some have no spicules, others only ancorse, and others again have both aucorse and styli. The ancorse are smaller than in the developed sponge, most frequently of a length of 0-017— o-02imin, and also rather fine. The styli are likewise small and very fine. The styli are arranged in a bundle about in the middle of the embryo, while most of the ancorse seem to chiefly placed in the circumference. None of the two forms of sigmata were seen in the embryos. This species is very similar and closely allied to the preceding one; in its outer form it is ecially distinguished from the former by the more or less marked circular arrangement of the PORIFERA. II. or branchlets. With regard to the spiculation sure distinguishing characters are found in the sigmata, especially in the presence of the fine, contort sigma, and in the size of the ancorse. Among the figures of the exterior, given in the Norwegian North-Atlantic Expedition, those quoted above may with great probability lie referred here, especially on account of the distinctly figured end-knobs. Of the figures of spicula, fig. 6 on PI. IV may with some probability be referred to the present species. Among the Cladorhiza-iorms taken by the Porcupine -Expedition, I suppose that the peculiar form in jar 65 mentioned by Carter (Ann. Mag. Nat. Hist. Ser. 4, XVm, 320) belongs here; according to the descrip- tion it might very well be a specimen with small or wanting branchlets. Locality: Iugolf station 105, 65" 34' Lat. X., 7 31' Long.W., depth 762 fathoms (bottom temperature -r-o°8C); station 117, 6c/ 13' Lat. N., 8° 23' Eong. W., depth 1003 fathoms (bottom temperature -f- 1 oC. seven more or less damaged specimens in all. Station 105 is situated to the east of Ireland, and station 117 south of Jan Mayen. Geogr, distr. The species is hitherto with certainty only known from the Norwegian Sea, where, besides by the Ingolf , it has been taken by the Norwegian North-Atlantic Expedition. If the form mentioned by Carter I.e. belongs here, it has also been taken in the Faroe-Channel at a depth of 345 fathoms with a bottom temperature of -=- i°i C. Accordingly, the specie.- is, at all events native of the cold bottom. 4. C. iniquidentata n. sp. PI. Ill, Fig. 6. PI. Nil, Fig. 5a- e. Slender, with branches issuing from a control axis : the tranches rather long, not arranged in one plan, swollen in the ends in a somewhat club-shaped way. The skeleton oj the generic type. S/ Megasclera styli u-jo — o-68mm; microsclcra of only one form, anisancorce unguifer i divided into branches from the. base. The sur/a ibility we are again led to reflect on a o ■'.'.am,; pennatuta and tin- following A 9_j PORIFKRA. II. branch Ids arc found. The skeleton is oj the typical Cladorhiza-structure, and consists of a central axis with lateral axes and fibres for branch/els ; but all these features are covered by the tissue, which finis forms a coating layer, from which only the short wart-like ends of the brandies project. Spicula: Mega- sclera s/y/i o-^h-o-yi"""; microsdera of three forms, anisancora unguiferm with five teeth trojj— o-ojy""". nata of two forms, large ones with slightly curved shaft and the ends prolonged in a tiagelliform manner in j — cri6'm'". small ones with compressed terminal parts o-o$j — o-ojj""". This species has a peculiar appearance, quite deviating from the other Cladorhisa-speaes. It is of erect form; whether it is fixed below by an expansion or attached by a root is not known, as my speci- mens are broken below, and Carter's description is based on fragments. The species may be described as a stem, set closely and all round with short, thick, more or less coalescing branches. Most frequently tin. branches are so short, that they may better be described as wart-like projections, only rarely they are a litte longer. As they are placed closely and irregularly, the sponge gets a more or less tuberous or round-lobed surface. The specimens in hand have, otherwise, an erect form, and are straight or a little curved, and besides the mentioned branches they have no ramifications; some skeletal parts, how- ever, indicate that the sponge may also divide into larger branches each of which is then of the described form. The largest specimen has a height of ca. 28omm, and the others are a little smaller. The thickness, which, on account of the close-set, round-lobed projections, can only be given approximately, is 10 — 20'nm. The length of the branches is at most i3mm, and their thickness at the base up to o.mm. On account of the powerful axes the sponge is stiff, also the consistency- of the tissue is rather firm, but brittle. The colour (in spirit) is yellowish white. The suffice is of a peculiar structure; as ends of fibres are projecting everywhere it is shaggy or prickly. Deep grooves or canal-shaped cavities going into the sponge are found between the ends of the fibres, so that the surface gets a reticulate-grooved appearance, what has been expressed by Carter in the name corticocancellata. The points of the branches are generally rounded, and they have no grooves, but show an even surface, shaggy from slightly pro- jecting spicules. All the part of the sponge that coats the axes is penetrated by a system of canals and cavities connected with each other, but separated by parts and beams of tissue, and these canals and cavities must be supposed not to belong to the canal system proper. As this structure is closely connected with the skeletal structure, a more particular account of it will be rendered under the description of the skeleton. The dermal membrane is a thin film covering the parts of tissue that separate the mentioned cavities, and supported by some spicules. Pores and oscula: As the mentioned canals and cavities must be supposed not to belong to the canal system, their outer openings cannot be oscula. Pores are found everywhere in the dermal membrane in the mentioned cavities; they seem to be small, as I have not with certainty measured any of them to a greater size than o-o65mi"; I sup- pose that these openings act both as incurreut and excurrent ones. Of course, it is possible that some oi the openings on the surface may be openings of real, excurrent canals; but this fact is scarcely to be decided by an anatomical examination only. The skeleton. In spite of the deviating exterior form, the skeleton is constructed after quite the same principle as in the other Cladorhisa-species. A thick, powerful, polyspicular axis of closely united, parallel needles stretches through the middle of the sponge. This axis has below a thickness of 4""'. It is more or less spirally twisted, especially in its lower part. Lateral axes a little upward PORIFERA. II. 95 ... directed issue from this axis in the same wa\ as in the preceding species. These axes run through the middle of the short lateral branches before mentioned, and accordingly they attain only a rather small length. Fibres issue from the axes of the stem and the branches, quite corresponding to the fibres of the branchlets in the preceding species. They issue all round, and most frequently they are- arranged in a more or less circular way, and they are inserted in the axes in the common manner, so that in a transverse section they are seen to meet in the middle (Woodcut fig. 5). The circular arrange- ment cannot be seen in the exterior, but when the layer of tissue is separated from the axes, a linglike structure is seen in these, owing to the basal parts of the small axes, which are inserted into the axis (PI. Ill, fig. S). Xow the only difference between this species and the preceding ones is that while in these the fibres inserted in the axes support free branchlets, they support in the present species the coherent part of tissue on the steins and branches, continuing from the axis out through this tissue, and their ends projecting a little. These fibres are in this species of about the same thickness through- out their length; sometimes they are a little curved. They may be somewhat branched, especially in their outer part, so that the number of projecting ends is greater than the number of fibres inserted in the axis. The part of the sponge coating the stem and the lateral branches and supported by the mentioned small fibres is not solid, but is, as before mentioned, pierced by a coherent system of cavities. A row of cavities is especially found inmost, round the axis, arranged like stories above each other, separated by the almost plate-shaped parts of tissue in which the small fibres run, but still connected with each other. Accordingly, a longitudinal section of the sponge reminds strikingly of the chambered root-stock of Cicuta virosa (PI. Ill, fig. 9). In the outer part of the layer of tissue the cavities are more canal-shaped, and thev open everywhere on the outside with round or roundish openings between the projecting ends of the fibres; their being at the same time connected with each other gives rise to the mentioned netlike structure. A comparison with the other species of the genus and especially the correspondence in tlu skeletal structure imparts the impression that the sponge-body coating the axes must be regarded as having arisen by a coalescing of branchlets, or must, at all events, be corresponding to coalesced branchlets, and that the mentioned system of cavities and canals, therefore, does not belong to the canal system proper, but is a secondary formation. This is also indicated by the fact that the cavities are abundantly connected with each other, so that one cavity in the sponge opens on the surface b\ several ways and to different sides. Whether free branchlets are found at any time during the growth of the sponge, and whether a real coalescing takes place, or tin- mentioned structui ars from the beginning, I am not able to decide, as I have had no young individuals1!. The described reg Fig. 5. Cladorhisa some degree arranged in bundles. The described con- struction of the axial skeleton is also distinctly seen in a longitudinal section. In the thinner branches no stratification is seen. The axes most frequently show a slight spiral twisting, which is, however, often very indistinct, or has quite disappeared, the spicules of the outer layer being scattered. In this species the axes are most frequently not cylindrical, but of an irregular contour, often with edge-- and keels; and irregular coalescing^ of various kinds may take place. The skeleton of the branchlets con- sists, as usually, of a fibre which is inserted in the axis and continues to the middle of the axis where most frequently several fibres meet. In this species these fibres have rather many spicules alongside; to be sure, they become a little thinner towards the point, but even there they consist of several spicules. The spicules of the part of these fibres that is inserted in the axis, are as usually spn in a fan-shaped way in the longitudinal direction; in the thinner branches tin inserted part of the fibres of the branchlets is of about the length of a spicule, but in the thicker branches and .stems also the branchlets continue to the middle, and then the part inserted in the axis gets a considerable length. In this case only the innermost part of the fibres of the branchlets, about to the length of oik spicule, is spread in a fan-shaped way. It must also be supposed that the spicula-layers of the thicker axes mentioned before are lavers of growth, and that the inserted fibres of the branchlets, with the exception of the innermost part, were at an earlier time outside the axis. In the layer of tissue out- side the axes some scattered spicules are found, some of which are situated just under the skin, parti}' between the branchlets, partly reaching a little into their basal parts. In the axes spougin is found cementing the spicules; it is most abundant downwards, and therefore the yellowish colour of the axes deepens downward, and at the base it becomes brownish. The axes have the common, somewhat hyaline appearance. Spicula: a. Megasclera; these, as already indicated in the name of the species, are diactinal; they are typical oxea with equal ends, without any discernible tendency towards styli. They are straight or slightly, often a little irregularly, curved, or they have in the middle a sharp, hut slight bend. From the middle they taper a little towards the cuds, but the point itself is rather short, or at most of middle length; an especiallv marked off outermost point is often found. The\ have not rare! swelling in the middle. These oxea, as mentioned, show no tendciic\ to become styli; on the other hand, forms are found with one rounded end, but only singh ; forms with both ends more 01 rounded are, however, also seen, and I am, in both cases, most inclined to regard these forms as secondary or irregular ones. Between the needles in the axes and those in the branchlets the onl) difference is that the former are generally shorter and thicker than the latter; besides, needles with the mentioned sharp bend occur far more frequently in the tissue and branchlets than in the axes. PORIFERA. II. When all sizes are included, the length is between 0-417—0-80""", and the thickness is 0-014— o-025mm For the needles of the axes the length may be given as being generally 0-417— o-6mm, and for the needles in tissue and branchlets ca. 0-55— o-8o,nm, and the thickness is rarely more than o-02imm. Some- times this difference is less marked, and it is especially found in the upper and outer ramifications, while down in the sponge and in the stems and the thicker branches it is more effaced. In the tissue fine, long pointed developmental forms are seen singly, b. ]\Iicrosclcra ; these are auisancoras unguiferse and sigmata of two forms, larger ones and smaller ones. 1. The ancorse are of the common Clado- rktza-iorm; they have a curved shaft and rather broad alee at the larger end. They have five teeth at either end, but forms with six teeth at the larger end are also found. The length varies from 0-026— 0-034""", and the thickness of the shaft from 0-0028—0-0035""". Developmental forms of the ancora; are found in small numbers. 2. The large sigma has a regular sigma-form ; these sigmata are plane or almost plane; the length is 0-09 — o-i2'nm, in by far most cases nearest to the latter length, tlie thickness is 0-0057 — 0-007'""'. Developmental forms in different stages were seen in no small numbers. These developmental forms are distinctly seen not to be cylindrical, but sharpened inward from a little over the middle and to the ends; this feature, on the other hand, is not to be seen in the full\- developed sigmata. 3. The small sigma is only found in the end of the branches, and is of the same form, with inwardly sharpened terminal parts, as the sigma occurring in the same way in the preceding species. It is likewise contort, almost always a fourth part of a turning. The length is 0-047 — 0-054""", and the thickness in the middle of the shaft about o-oo2mn>. The ancora; and the large sigma occur partly throughout the tissue and partly in the dermal layer, especially the ancorae are abundantly present in the outermost layer of the branchlets. The small sigma only occurs in the point of the branches and not in all of them, but only in those that are distinctly swollen; here it is 1 abundantly. On the other hand, the large sigma is here only seen quite singly. Embryos. Embryos were also in this species found rather copiously in the tissue. They are roundish or most frequently oval, and they are surrounded by a thin membrane. Their size is about I!v the examination they proved to be either without spicules, or only provided with develop- mental forms of the ancora;, but these were found rather copiously. The developmental forms were mostly rather young stages, they had a length of 0-024 — 0-027""", or about the same length as the ancorae of the grown sponge. The embryos are situated in the tissue outside the axes, they are fre- quently found at the base of the branchlets, or in this base itself; in a few cases they are seen out in the middle of the branchlets (Woodcut, Fig. 6). According to this I suppose that they leave the sponge by this way, and so we are again led to regard the branchlets as oscula. I have, however, not been able to find any canal, and accordingly, if such a one is found, it must be supposed to be ed. The fibre of the brauchlet is almost always found in one side, and the canal must be supposed run alongside of it. Also the embryo is placed in one side of the branchlet beside the fibre; it distends the branchlets in the middle, and on the sides where the fibre is not found, it is surrounded by a thin membrane only filled with microsclera. It is to be remembered, however, that the occurrence he embryos in the branchlets may also be supposed to be owing to the fact that they develop here in other places in the sponge. The figure presented by a branchlet with an embryo in it, involuntarily directs the thought PORIFERA. II IOI to the figure given by Wyville Thomson, in The Depths of the Sea 187, of Chondrocladia virgata. In this sponge all the branchlets show a swelling in the middle mentioned by the author as a dark greenish oval mass of granular sponge matter , a description that might very wel be used of an embryo situated in the branchlet. Wyville Thomson says that the branchlets end with a very narrow osculum. Carter also mentions the swelling, but has found no osculum; it may perhaps have been distinct, when the sponge in its fresh state was examined by Wyville Thomson, and have been closed later. If the mentioned swellings in the branchlets are owing to embryos, there is the curious peculiarity that an embryo is found in each branchlet. The quoted one of Armauer Hansen's figures of the exterior may with certainty be referred to this species; also one of the specimens of his C. abyssicola which I have examined proved to be the present species. ( >f the spicula-figures those on PI. IV, figs. 4 — 5 belong with some probability to this species. Also Fristedt's C. abyss/cola proved, by my examining a fragment sent to me, to be the present species. Locality: Station 15, 66° 18' hat. N., 2 50 29' Long. W., depth 330 fathoms (bottom temperature -=- 075 C), station 143, 62" 58' hat. X., 7 1:19' Long. \Y., depth 388 fathoms (bottom temperature -f 04C); further 65° 57' Lat. N., 27 00' hong.W., depth 336 fathoms (bottom temperature 0°) (Wandel). The mentioned stations are situated in the Denmark Strait and north of the Faroe Islands. The species appears to be a native of the cold bottom, or the border of it. From station 3 with a bottom temperature of CP5 C. we have a fragment consisting of denuded skeletal parts. This fragment has surely been dead long, as a Suberitid, and other forms are growing on it, and it has moreover lost something of its original firmness. Therefore it must lie supposed to have been removed from its native place. Geogr. distr. As mentioned the species has been taken by the Norwegian North-Atlantic Expedition and in the Baffin Bay, depth 116 — 215 fathoms (Fristedt I.e.). ■ n. Branchlet with eml 1 The fibre is running in the The c' 1309 fathoms; with the exception ^\ abyssicola they are all of them natives of cold water. The species from the Atlantic and the Pa have a bathymetrical range from 700 3000 fathoms; with regard to these species the bottom tempt ture of the localities at which they have been obtained varies from ca. o° to 4°4 C Fahren- heit). The bottom temperature o C. (3.! 1 Fahrenheit) applies to the southernmost species C. 1 R. and I), obtained at 53 55' Lat S., [38 35' Long. E. at a depth ol ithoms. [02 PORIFERA. II. The Cladorhiza-species described at present are the following ones: [872. C. abyssicola O. Sars. 1876. - corticocancellata Cart, (as a variety of abyssicola). [887. - abyss/cola war. rectangular is R. and D. The Pacific. 1SS7. - - linearis R. and D. The southern Pacific. [887. - moniliformis R. and I). Southwest of Australia. [887. - longipinna R. and I). The northern Pacific. 1887. - similis R. and D. The southern Pacific. 1887. - tridentata R. and D. Between Prince Edward Island and Crozet Island. 1887. - pentacrinus Dendy. Northeast of New Zealand. 1902. - flos abyssi Tops. Off the Cape Verde Islands. - gelida mihi. - tenuisigma mihi. - iniquidentata mihi. - oxcata mihi. The two varieties rectangularis and linearis established by Ridley and Dendy are surely independent species. In Zool. Anzeig. XIX. 532, Kieschuick has established a species C. deprcssa. As it is from a littoral locality it is scarcely a Cladorhiza, and as Thiele, in his account of Kiesch nick's species (Abhandl. Senckenberg. Nat. Gesell. XXV, 1903) has been unable to find anything whatever that might correspond to it, the species must be regarded as non-existing. With regard to the Asdestopluma-species described under the generic name of Cladorhiza see under the genus Asbcstophima. Chondrocladia Wyv. Thomson. Erect, branched in different ways; often a central axis with lateral branches which may be papillose, or the branches gathered at the top: sometimes branched like a free, or finally of a more irregular form. The skeleton is in close accordance with the form, and consists in the axis or axes of powerful spicula-fibres, and of similar, but thinner ones in the branches. Spongin is found in the fibres. Spicule/: Megasclera sfyli, and sometimes finely spina Ions styli in a special layer coating the stalk: microsclera: flic characteristic microsclera are isancorce unguiferce of one. two, or three sizes with from three to nine teeth at either end. to which forms sigmata are (always) joined. 1. C. gigantea Arm. Hans. PI. IV, Fig. 1. PI. XIII, Fig. 2 a— 1. 1880? Cladorhiza grandis Verrill, Proceed, of the U. S. Nat. Mus. II, 1S79, 204. 1885. Desmacidon clavalum Annauer Hansen, The Norwegian North-Atlantic Exp. XIII, Spongiadse, 14, PI. II, Eg. 11. PORIFERA. II. to. [885. Desmacidon nucleus Armauer Hansen, ibid. PI. Ill, fig. 1, PI. VI, fig. 17. 1885. Desmacidon giganteum Annaner Hansen, ibid. PI. II, figs. 12, 13, PI. VII, fig. 8. 1885. Desmacidon arcticum Annaner Hansen, ibid. 15, PL VI, fig 1887. Cladorhiza nobilis Fristedt, Vega-Exp. vetensk. Iakttag. IV, 456, PI. 25, figs. 60 65, PI. 51. fig. 26. Erect, club-shaped, on the upper part with a number of short, papillose branches swollen towards the put nl : below the axis is dissolved to et branched root. ,1 layer coating tin stalk and mot and pro- vided with special spicules present. '/Vie skeleton 0/ the generic type, consisting />/ a powerful, I- spirally twisted spicula-axis through fin- middle oj the sponge, and thin spicula-axes in the papilla. Spicula: Megasclera styli of two sizes, long ones in tin- axes. 1-2—2""", shorter ones in the other parts of the body o'<;6 — r2"""; finely spinulous styli in the layer coating the stalk o'i/8—o-J4"""; microsclera of three forms, isancorce unguiperce of two forms, large ones with six teeth 0-057 — o-oyjmm, small with six to nine teeth O'OiS — o-ojmm, sigmata with compressed terminal parts O'Ojy—O'Ojj""". This beautiful and interesting species reaches a considerable size, as lias already been expressed by Armauer Hansen in the specific name, although his specimen had only half the length of the largest specimen before me. The species consists of a stem, dividing below, first into rather thick branches, then by and by into thinner ones, so that a rather richly branched root is formed. The stem continues upwards, and increases in thickness in its upper half, so that the sponge becomes about club-shaped. The upper, thicker part is set with a great number of papillae, not regularly arranged. The papillae have a broadly conical base passing into a thinner stalk which again ends in a more or less swollen head. The papillae may otherwise be somewhat different in length and form, the length of the stalk may be different, and the end may have a more or less marked head-like swelling. The papillae may also be somewhat differently directed; in the specimens in hand most of them are more or less turned downwards, only the uppermost ones are directed upwards. Up to where the lowermost papillae begin, the root and stalk is coated with a layer provided with special spicules and of the same character as that found in several Asbestopluma-species; the layer is here very thin, and it is highly filled with mud, so that it must be supposed that the sponge has been sunk in the bottom so far as the layer reaches. The largest specimen in hand has a height of 43 "", of which the stalk and root make about the half part; the stalk is ca. 21""" thick, and the greatest thickness above is - The length of the papillae inclusive of the conical base cannot be given exactly, but it does not exceed 25"™, and in their thinnest stalk-shaped part they have a thickness of 3- s " ;. Armauer Hansen's specimen was 22"" high, and two smaller specimens before me are ca. is": high, tin- other measures being in proportion to this. The colour (in spirit) is yellowish white; the lower part, which is covered by the coating layer, is, on account of the mud in it, dark gray, which colour ceases with a sharp boundary line. On account of the axial skeleton the sponge is firm and stiff, and the layer has outermost a rather hard, crusty consistency, but it is inelastic and somewhat brittle. The outei enisle tissue is not sharply bounded inward, but passes more or loss evenly into the inner, sol tissue. The surface is apparently smooth, but under a magnifying glass it i> seen to W- finely shaggy. The outer crusty layer may rather easily Ik- peeled off, while the outermost membrane, the dcrvtal membrane proper, may ho distinguished, but cannot, or only with difficulty, be isol may he PORIFRRA. II seen in the dermal membrane, and were measured to a size of ca. o-02mm. They are only observed with difficulty, the outer layer of tissue having the character of very small subdermal cavities situated within each other and separated by membranes, and the pores piercing only the very outermost mem- brane. From the subdermal cavities cylindric canals continue inward which canals may be observed, when a piece cut off parallel to the surface is regarded from the inside. Oscula: Separate great oscular apertures are not to be found, but it is likely that the papilke carry the excurrent openings. as tla- inner tissue between the central axis and the outer layer is lacunous, and canals are running longitudinally in the papilke, partly in the tissue between the axis and the outer layer, partly as sharply and distinctly bounded canals in the outer layer. Outermost in the terminal part of the papilla a cavity is found, or the middle part of the head of the papilla consists of a somewhat lacunous tissue without spicules. Now the end of the papilla is copiously provided with poreshaped openings, and as I suppose the said canals, at all events those running in the inner tissue, to be excurrent canals, I suppose the openings in the terminal part of the papilla to be excurrent ones. The skeleton consists of a strong axis running through the middle of the sponge, and also continuing into the branches of the root. The axis is not quite compact, but is composed of a number of close-lying, strong fibres. In its lower part the axis is spirally twisted; this twisting is here very distinct to the naked eye, as it is not the spicules of the single fibres which are spirally arranged, but it is the whole, of fibres composed stalk that is twisted, so that it gets some resemblance to a rope. In the single fibres, on the contrary, the spicules are placed in the longitudinal direction of the fibres without any twisting. The twisting is most marked in the lower part of the stalk, but upward it becomes less marked, and at last it is lost; it disappears also in the root-branches. In the largest specimen the thickness of the spicula-axis is ca. 14™™. Through the middle of each papilla runs a fibre, which is formed by one of the fibres composing the axis bending off and passing through the papilla. Where the fibre bends off from the stem it is supported by some spicules placed in the angle and reaching to the middle of the stem. The papilla? evidently correspond to the branches of the Clado- rktsa-sipecies. The skeleton of the other parts of the sponge supports the layer of tissue that coats the axis and its branches, i. e the papilke. In the crusty outer layer this skeleton consists of a verv dense layer of needles lying irregularly in all directions. Part of the spicules project through the surface and makes it shaggy. Down on the stalk the la\ er of tissue consists only of this outer, firm part, and it is easily separated from the stalk. In the thicker part of the body, 011 the other hand, the crusty layer passes inwardly, with a more or less indistinct bordering, into the soft, more lacunous layer of tissue nearest the axis which layer is provided with fewer spicules, partly scattered, partly gathered in bundles or shorter fibres. Also here the whole layer may be easily separated from the axis. Down nn the stalk the crusty layer is about 2mm thick, higher up in the expanded part it reaches a thickness of 3 — 5'"". In the papillae the construction of the skeleton is the same; in a transverse or longi- tudinal section the fibre is seen in the middle, then a soft layer with fewer spicules, and outermost the lv layer (Woodcut fig. 7). The soft tissue between the crust and the fibre is here rather thin. The fibre continues to the point of the papilla, where it ends at the outer end of the cavity there; it has an average thickness of about i""n. The coating layer of the stalk and root is thin, and does not exceed m thickness. It is of a character somewhat different from what it is in the Asdes/op/uv/a-species, PORIFERA II consisting of closely and irregularly arranged spicules oi a special form, besides being interwoven with the common axial styli. It might be said that it was the outer part of the crustv layer, which was interwoven with the special spicules, but then it must be remembered that the coating laver may easily be removed as a separate laver. In the axis a rather copious, yellowish mass of spongin is found cementing the needles of the single fibres and coating these fibres with a thin layer; on the other hand, the fibres are not, or only to a slight degree, united by spongin, and they seem chiefly to be held together by anastomoses passing very obliquely from one fibre to another. In the skeleton outside the axes no spongin was observed. Spicula: a. Megasclera are styli, dividing into two forms, which, however, are not sharply separated: long, straight styli chiefly forming the axes, both the central one and those of the papillae, and shorter, most frequently evenly curved styli found in the other parts of the body. The long styli are straight or sometimes slightly and a little irregularly curved; they taper a trifle from the middle outward: at the rounded end there is a more sudden tapering, the point is short and oftenest stubby. The length reaches 2""", and may go down to ca. i-2mm, and the thickness is 0-03 down to ca. croi7mm. The short styli are almost always slightly and regularlv curved; they have likewise a sudden tapering at the upper end; the point is somewhat longer than in the long ones, and it is gener- ally sharp. The length is o"56min up to ca. r2mm, and the thickness is in proportion cron— cro24ram. Thus the short styli, while having a length like the shortest ones of the long styli, are of greater thickness; as before mentioned, however, the two groups are not sharply separated; neither are they so with regard to their occurrence, some of the shorter needles being found in the axis, while long needles may be found in the other parts of the body, only, how- ever, in rather small numbers. Of both forms quite fine developmental forms are found, but only in small numbers. Tin spicules of the coating layei of the stalk are curved, often somewhat irregularly curved, styli: the head-end shows often an inconsideri scarcely perceptible swelling which is often placed a little below the end; they taper move or less towards the opposite end, which is more or less broadly rounded. They are finch spinulous, -0 fineh that it is seen at most as a slight granulation, when the needle is not seen under ver\ high magni- fying powers. The length varies from o'liS 0-3 p"", and the thickness at the upper end 0-0015— 0-004"1'"; there is no fixed proportion between the length and thickness, b. M ■• these are isauconc unguiferse of two forms and sigmata. 1. The ancorre oi the large form hav< evenl) curved shaft and six lanceolate teeth at either end. At eithei end mud two nai Tli.- [ngolf-l xpeditcon VI. ; Fig, 7. Clio m Hans. Longitudinal section through the end of a p with a cavity i" the cuter end. Outermost the crust) layer is found, then the softei n>sm- with fewer Spicules and in the middle tilt axis. A leu canals are seen. IO£ PORIFERA. II. continuing down along the shaft and being a little longer than the teeth. The length of this ancora varies from 0-057— 0-077""", and the thickness of the shaft is about 0-004 ,mn. Younger forms in different degrees of development are also found. 2. The small ancorse have a rather highly curved shaft, but there may be some difference in the degree of curving; the number of teeth may be different, from six to nine, it seems most frequently to be seven or eight. Some irregularity is not rarely seen, so that some teeth are larger than others, or that more teeth are found on one side of the median line than on the other. Some instances are also found, in which the number of teeth at each end is different, for instance six and seven. At either end of the shaft two small ake are found. The direc- tion of the teeth is somewhat varying in this ancora, so that they are either directed almost horizon- tally outward, or more or less downward, i. e. towards the middle. The length is rather varying and is between o-oi8 and o-03mm, and the thickness of the shaft is ca. o-oo28mm. Developmental forms of this ancora were seen quite singly. 3. Sigmata; these are of a form quite similar to those occur- ring in most Cladorfoza-species, with compressed, inwardly edged terminal parts; they are also contort, almost always one fourth of a turning. Their length varies from 0-037 — o-045mra, and the thickness in the middle is ca. o-oo2mm. The ancorae occur everywhere in the sponge in tissue and in dermal layer; they occur also in the axis in the tissue between the single fibres of which it consists; at the point of the papillae the small ancora is wanting, or is only present in small numbers. Sigmata occur only in the papillae, especially at the point, and they are not of equally frequent occurrence, being more scarce at the point of some papillae, while in others they are found more copiously. Embryos. Embryos were found in one of the two smaller specimens; they were rather con- spicuous, as they are very large, and shine through the surface on account of their deeper yellow colour. They are uncommonly large, reaching a diameter of 5mm; they are round, most frequently much flattened so as to become almost discoid or lenticular. They are placed in the body of the sponge between the skin and the axis, often in such a way as to be lying partly in the soft tissue, partly in the hard outer layer, sometimes also entirely in the outer layer in lenticular cavities; in the latter case the surface may be bulged out by them, and the layer separating them from the surface may be rather thin. Of spicules they have both megascleres and microscleres. The megascleres are thin and fine styli, quite reminding of developmental forms of the styli of the grown sponge; their greatest measured length was o-Se/""1. Of microscleres the large ancora occurred rather abundantly, and a few developmental forms of this ancora. These ancora; are somewhat deviating from those of the grown sponge, their shaft being thinner and their teeth somewhat longer. Also the small ancora occurs, but only in very small numbers. Then forms occur, also in very slight number, that are, as in size, transitions between the two kind of ancorae, so that we must suppose the possibility that the cells forming the ancora; are not from the beginning distinctly separated into two kinds; it is, to be sure, to be supposed that later, when the ancorse are found as two distinctly separated forms, each of these is formed by a distinct kind of cell. The large ancora; in the embryos are of full length, they were even measured to be a little longer than has been observed in the grown sponge, viz. to o,o84mm. As I have had type specimens of all the four species established by Armauer Hansen, I have been able to decide with certainty that they belong all to one species. Three of the species, //'/, nucleus, and arctica, are only loose papillae of gigantea, and it is a singular thing that PORIFERA. II. 10; Armauer Hansen has not recognized this fact, as their exterior shows it plainly enough, and the spicules are the same. In arctica he has found sigmata, which shows that he has examined a pi of the terminal part of the papilla. When he also mentions anc. 2 3 for this species it is not correct, snch ancorse are not found. Armauer Hansen does not in any of his descriptions render any account of the fact that there are two forms of ancorae. Although clavata is the one first described I have thought it correct to use the name gigantca, as this name has been given to a whole speci- men of the sponge, and to this belongs also a recognizable figure, while the other species have been established on small fragments. I have likewise examined the type specimen of Fristedt's 1 rhiza >iol>ilis. so that the identification is sure; otherwise his description and figures show plainly enough that the question is of the present species. Fristedt draws himself the attention to the resemblance, and the only distinguishing character he mentions is that his species, in contradistinction t<> that of Armauer Hansen, is hollow; the case is, as might be supposed, that the body is torn from the axis, the consequence of which is that the species apparently is hollow; as the body and the axis are easily separated, a tearing out of the axis is an easy thing. Fristedt gives the greatest length oi the needles to o-9'm"; that he has not found any longer needles corresponds with the fact that he has not had the axis, in which the longest needles occur; otherwise I have in his specimen found needles up to rj",m long. In contradistinction to Armauer Hansen, Fristedt has found the spicules of the coating of the stalk; he does not mention, however, in what manner they occur. As to the occur- rence of the skeletal spicules he expresses himself in a very obscure way saying: These spicules are placed both in the body and in the arms nearest the central cavities . As he does not mention the way of occurrence of the spicules of the stalk-coating, I suppose it to lie this expression that has led Topsent to suppose (Resultats du Voyage du S. Y. Belgica, Spongiaires, 26) that these spicules 01 through the whole height of the sponge. That they only form a stalk-coating also in Fristedfs specimen is seen from the figure, which shows a dark-coloured layer on the small part of the stalk that is present, and also the examination proved it to be the fact. As mentioned bj Fristedt, some of the papillae anastomose; it is an interesting fact that this feature is also found here as in sev Clador/izza-species; it lias not been observed in the specimens before me. Fristedt says that the large ancorae have more teeth than the small ones; this statement must be due to an error, neither is it seen in the figure; otherwise he does not mention the number of teeth.- The Cladorlnza grandis established by Verrill would seem, according to the description of its outer Eorm, to be identical with gigantea, but this fact cannot be decided, as Verrill does not mention the spicules .it all; ii the) prove to be identical Verrill's name has the priority. The species Cladorhiza concrescem from the West Indies established by Schmidt (Spi Meerbuseii von Mexiko, II, r88o, .S3, Tab. X, Fig. 8, 9) must be a ver) closely allied specie- It- form i; quite similar, and it has also two forms of ancora; the large ancora has m\ teeth, but oi the -mall ancora it is said that its teeth are so long as almost to touch each other in the middle. Schui: expression deii Schlamiubeleg des Slides .... shows with rather great certaint) that this sp< has a layer coating the stalk, which fact 1- not known to be found in othei than gigantea. Locality: Station \. 64 07' Lat. N., n 12' Long. W., depth 23 I ttom temperature IOS PORIFERA. II. j 5 Q); station 64, 62° 06' Lat. N., 190 00' Long. W., depth 1041 fathoms (bottom temperature 3°i C); station toi, 66° 23' Lat. N., 12° 05' Long. W., depth 537 fathoms (bottom temperature -4- o°7 C.); station 138, " I..it. X., 70 56' Long. W., depth 471 fathoms (bottom temperature -f-o°6C); further it has been taken at 62' 53' Lat. X., 4° 14' Long. E., depth 450 fathoms (bottom temperature negative), and 62° 38' Lat. X., 4° 40' Long. E., depth 350 fathoms (bottom temperature -=- o°5 C.) (Ad. Jensen, the cruise of the Michael Sars up2i. The first four localities are situated between Iceland and the Faroe Islands, with the exception of station 64, which is situated south of Iceland; the two localities from the cruise of the Michael Sars- are in the Faroe-channel. At the first four localities only fragments and loose papillae were obtained, at the last ones on the other hand three specimens. As appears from the above the bottom temperature is negative at most localities, and only positive at stations 4 and 64. From station 64 we have only a quite damaged fragment, which may very well have been dragged in the trawl from an earlier station. From station 4, on the other hand, we have a fresh fragment; this station with a depth of 237 fathoms, is situated on the ridge between the northern, cold depth and the southern depth, so it may well be understood that the species may occur here. I suppose that the specimen in question is a fragment, but it might also be a quite young individual, in which latter case there might be the possibility that the specimen would not have attained its full development on this locality. Geogr. distr. The species has been taken by the Norwegian North-Atlantic Expedition, partly between Iceland and the Faroe Islands or a little farther north, partly off the Norwegian coast, at the two first places at depths of 299 and 1163 fathoms, at the latter place at a depth of 452 fathoms; the bottom temperatures were -=- o°3, -f- i°i, and -f- i°o C. (Armauer Hansen mentions further station 58, but this station being no zoological one, the statement is presumably erroneous). It has further been taken at East-Greenland, depth 130 fathoms (Fristedt). If C. grand is Verrill proves to be identical with the present species, it has accordingly also been taken off Nova Scotia, among other localities at 430 17' Lat. N., 60° 58' Long. W., depth 180 fathoms. The species is now known with cer- tainty from different localities in the whole northern depth between Greenland and Norway with a bathymetrical range from 130— 1 163 fathoms. The species seems chiefly to be a native of the cold bottom, although it scarcely exclusively belongs to the cold area ; the fact proves to be that almost all the localities, to be sure, are negative, but they are situated at the very border of the cold area, and the Ingolf-station 4 forms an exception being situated quite up on the ridge between the cold area and the warm depth and having a bottom temperature of 2°5 C. An exception to the other side is formed by station 51 of the Norwegian North-Atlantic Expedition, which is situated in the cold area proper with a depth of 1163 fathoms and a bottom temperature of -=- i°i C. The fragment from Ingolf-station i must be regarded as uncertain. If C.grandis Verrill proves to be identical with the present species, it accordingly occurs at the eastern coast of America much farther south and at localities with positive bottom temperature, and this does not seem to be improbable. Note. Carter, in the a head passing evenly, without any marking, into the shaft of the needle. They are quite slightly fusiform, being a little thinner below the head-end than in the middle. The length varies from about 0-45 0-65""", and the thickness is croo6— cnx>9mm. The shorter and thicker spicules in the projecting bundles are somewhat fusiform, being thickest in the middle, and the point is not so long. Their PORIFERA. II length is generally 0-29 — 0-4""", but, as before mentioned, transitions to the skeletal spicules are found, especially among the spicules that are placed immediately below the dermal bundles. The thickness is 0-009— 0'OiS'nm, but in some individuals it does not exceed o-oi4mm. Of the skeletal spicules devel- opmental forms were seen, down to quite fine ones, but in very small numbers, b. Microsclera; these are of two forms, isochelae palmatse and toxa with spined ends. 1. The chelae an. of the common form; their shaft is about straight or quite slightly curved, the middle part between the two terminal parts is straight or a little curved inward; the length of this middle part is generally some- what less than one third of the whole length. The tooth is about as long and broad as the The chela; vary somewhat as to size, and this may again to some degree influence the dimension the different parts. The length is 0-007 — 0-0128""", most frequently near the latter size; the breadth is ca. o-oo2'nm. Developmental forms were seen singly as quite thin, recurved staves. 2. Toxa. The general form of these is one that has in the middle a strong curve while the ends are evenly curved to the opposite side, and their outer part is most frequently straight. They are generally more 01 less twisted in the middle, and most so, it would seem, in the smallest bows. From the mentioned and by far most common form they may vary in different ways, especially so, that the curve in the middle becomes more open and the legs more straight, so that we may yet a bow with a very great angle and only one curve. The outer ends of the bow are spined for a quite short waj ; the spinosit} may be a little varying, but generally there are comparatively few, rather coarse spines. These- bows are exceedingly varying as to size; thus the length, which is somewhat dependent on the curve, varies from 0-07""" quite up to o-32mm; the thickness, which is the same through almost the whole length of the bow, varies in proportion to the size from about 0-OOi — 0'004mm. All these sizes must be regarded as fully developed bows; neither would the small ones by a continued appositiou grow t< the form of the large ones, and they have likewise all, also the smallest ones, spined ends. ( hi the other hand small bows occur, thinner than the fully developed ones of tin. same size, and almost not at all spined, or only with small spines; these, no doubt, are developmental forms. Thus the spines are not found from the beginning, but only formed by and by. Of the microsclera the chelee are found in exceedingly large numbers both in the dermal membrane and throughout the tissue, the bows are found in the tissue in somewhat smaller numbers. As I have examined the type-specimen described by Schmidt I.e., I have been able with certainty to establish the specific identity between Schmidt's Suberitcs arciger and Vosmaer's Artc- misina suberitoides. Already Fristedt 1. c. draws the attention to the probability of the identity. It may easily be understood that Schmidt has overlooked the chelae, as the) an exceedingly small, their smallest size being perhaps the smallest chelae occurring at all. Schmidt further states that besides the common needles a form occurs which variirt von der Kugelform bis zur Gestalt einer kurzen, an beiden Enden stumpfen Nadel , and he figures two such bodies; this fact, togethei with the chelae, has for Yosmaer been the reason win' he has not united tin two species. The bodies mentioned by Schmidt are, however, onlj monstrosities of the kind that is upon the whole not rarely found in sponges. It seems especially to be the dermal spicules, which are sometimes trans- formed in a monstrous manner. Locality: Station 28, 65° 14' Lat. X., 55 42' Long. W., depl fathoms; Station [27, 66 33' u^ PORIFERA. II. Lat. X., 2u 05' Long. W., depth 44 fathoms; Greeuland, Proven (Bolbroe, Schmidt's type specimen); the Davis Strait 65° 27' Lat. N., 54' 45' Long. W. (Wandel); East-Greenland (the East-Greenland Ex- pedition 1891—92); Forsblad's Fjord, depth 50 — 90 fathoms, Hnrry Inlet depth 50 fathoms (the Amdrup Expedition 1900); twenty miles east of Seydisfjord, depth 135 fathoms (Wandel); 64° 27' Lat. N., 13° 27' Long. W., depth 84 fathoms, 64 58' Lat. X., n3 12' Long. W., depth 300 fathoms (Ad. Jensen, the cruise of the Michael Sars 1902). The mentioned localities are situated in the Davis Strait, off East- Greenland, North and East of Iceland, and between the Faroe Islands and Iceland. Geogr. distr. Besides at the localities mentioned above, the species has been taken between Norway and Spitzbergen, 720 36-5' Lat. N., 240 57-5' Long. E., depth 140 fathoms ( Willem Barents:)); Spitzbergen, depth 40 fathoms, Kola Bay depth 95 — 100 fathoms (Fristedt); Nova Scotia, 43 03' Lat. N., 63 39' Long. \Y„ depth 85 fathoms (Challenger). Thus the species is exclusively a northern one, its southernmost boundary being 430 03' Lat. N., and, as usual, it goes only so far south at the eastern coast of America. Its longitudinal distribution is from the Davis Strait to Spitzbergen. It has been taken at depths from 40 fathoms (Spitzbergen) to 420 fathoms (the Davis Strait, 65° 14' Lat. N.). 2. A. apollinis Ridley and Dendy. PI. XIII, Fig. 4 a— g [887. Amphilectus apollinis Ridley and Dendy, Challenger Report, Monaxouida, XX, 124, PI. XIX, figs- 3< 3 a— c- Formed as a thick incrustation or flat cits/lion. The dermal membrane a thin Jilm with a reti- culation 0/ spicules. The skeleton a halichondroid reticulation of polyspicular fibres, spicula-bundles and single spicules. Spicula: Megasclera styli of ' two forms, larger ones, smooth, or with a slight crenulation at the head-end. crjj — u-S""". in the main skeleton ; smaller ones, with very slightly spined head-end, 0'2p—o-jpmm, in the dermal skeleton ; microsclera 0/ two forms, small isochelcr palmatce 0-014 — O'OiS""", toxa, large, spined ones o-jo""", smaller, smooth ones 0-085 — 0-28""". Of this species we have only two fragments with a greatest extent of 35""". Ridley and Dendy describe their species as \ the diagnosis) some difference as t< form and skeletal structure, but the species seem here, as in several other genera, to form a continuous -cries; //. couulosa R. and D. occupies, as already stated by the authors, an intermediate position. As to the microsclera, the genus will comprise forms with arcuate cheke, with common palmate clu o ') Ridley ami Dendy say that Ehlers established tin- genus without giving any diagnosis; this, how, the case as Ehlers, on p. 32, gives .1 diagnosis <>i the genus rather good foi its time. jlS PORIFERA. II. and with the peculiar palmate chelae that were characteristic of Homoeodictya in the sense of Ridley and Dendy. Thus the genus is divided in three groups, which groups, however, can scarcely be of generic importance, as arcuate and palmate chelae may occur in the same species (for inst. Esperi- opsis forcipula Ldbk.), and the peculiarity of the Homaodictya-chela is also found elsewhere, for instance in several Esperiopsis-species (see p. 15). At present it is not possible to decide, which of the described species are to be referred to Desmacidon, and which to Homceodictya. The case is that when no figures are given, it cannot be seen from the commonly used expression tridentate isocheke whether the question is of arcuate chelae or ancorae; and even if figures are given, they must be good ones to give sure information. I shall here therefore only enumerate some species, which with certainty belong to Homceodictya: Microsclera. H. palmata Jolmst Homceodictya-chelae. 1885. - (Myxilla) flabelliformis Arm. Hans Chelae arcuatae. 1887. - (Desmacidon} conulosa R. and D Chelae palmatae. 1887. - ( — ) ramosa R. and D Chelae arcuatae. 1887. - kerguelenensis R. and D Homceodictya-chelae. 1887. - grandis R. and D Homceodictya-chelae. 1889. - (Fibula rial raphidifera Tops Chelae arcuatae, rhaphides. 1903. - (Desmacidon) setifera Tops Chelae palmatae. 1904. - ( ) peltata Tops Chelae arcuatae, rhaphides. None of these species have sigmata, and it may be doubtful, whether such are found in the genus. 1. H. flabelliformis Ann. Hans. PL IV, Figs. 2— 3. PL XIII, Fig. 5 a— e. 1885. Myxilla flabelliformis Armauer Hansen, The Norwegian North-Atlantic Exp. XIII, Spongiadae, 12, PL II, fig. 14, PL VI, fig. 6. 1903. Desmacidon clavellata Arnesen, Bergens Mus. Aarsberet 1903, Nr. 1, 13, Taf. II, Fig. 2, Taf. IV, Fig. 4. Erect ' , stalked, broadly leaf-shaped (grown specimens) or club-shaped (young specimens). The dermal membrane a thin film with scattered spicules. The skeleton consists of polysplenia)- primary fibres passing from the sialic into the leaf and bending in a sheaf-like way to all sides towards the sur- they are connected by transverse spicules most frequently placed singly. Spicula: Mcgasclera oxca of two sizes, large ones in the skeleton. 0-41— o-jj'""' '. smaller ours in the skin, 0-268— o-jj"""; micro- sclera chela arcuatm, highly curved. 0-030— 0-04""". Of this species we have two larger, somewhat damaged specimens, and two small ones. The species has below a stalk attached by a somewhat expanded basal part, but the specimens in hand are torn off, with the exception of the smallest one, which is attached to a stone. Arnesen 1. c. P0R1FERA. II. II(, says that it sits on serpula-tubes, muscles, stones etc. The stalk passes into a rather thick, more oi less fan-shaped leaf; this leaf is thickest in the middle, but becomes thinner towards the edge. The largest specimen has a height of ca. 90'"'", and the leaf has a similar breadth. The greatest thickness of the leaf in the middle is ca. 17""", the stalk lias a height of _:<>""" and a thickness of fully iom,n. The other specimen is a little smaller, and the leal especially is less broad. Of the small specimens one has a height of 24""", half of which is a stalk scarcely 2mm thick; this specimen may moreproperly be called club-shaped than leaf-shaped, its upper part having a breadth of <;!'"" and a thicknes> oi 6™'". The smallest specimen is only 12""" high, of which the stalk makes about the half. This specimen is quite club-shaped and has a greatest breadth of 3""". The consistency is rather loose, but the stalk is considerably harder. The colour (in spirit) may be given as light brownish gray. Of the surj I dare, on account of the condition of the specimens, say nothing with certainty, but doubtless the ends of the fibres project making it sparingly shaggy. The dermal membrane, to judge from the few places of the sponge wdiere it is kept, is a thin film provided with scattered oxea and with very close-lying chela;. Oscula and pons I have not been able to observe on my specimens, but on a young club-shaped specimen, kindly sent me by Miss K. Arnesen, an osculum was found at the top, as has been figured by the authoress I.e. Rather close-standing canals run through the sponge continuing from the surface horizontally inward or somewhat downward; these canals convev an impression of being larger on one side than on the other, and perhaps therefore, in the grown, leaf-shaped sponge pores and oscula have been localized each on their side of the sponge. The skeleton consists in the stalk of close-lying, strong, polyspicular fibres connected by power- ful spiculad)undles, so that a solid network is formed. This skeleton forms the greater part of the stalk, only a little network of thinner fibres being found on the outside. From the stalk the fibres continue into the leaf and bend to the sides in a fan-shaped way, branching and by degrees becoming thinner; thus the outer branchings form the edge of the sponge. The fibres, however, bend also and ramify in a fan-shaped manner towards the two surfaces of the sponge, where accordingly their outer ends projects every wdiere. Thus these primary fibres have a rather regular course, and the distance between them is also rather equal, ca. 0-29 — crd""". The fibres are thickest in the middle of the sponge and may here reach a thickness of o'2mm; then they consist of many spicules alongside, but through their outward course they become thinner and go down to a thickness oi only a tew spicules, in a lew places even they consist of only two spicules alongside. In the stalk the fibres may reach a thickness of o'27mm. The primary fibres are connected by transverse spicules most frequently single, onl\ some- times two or three together; the transverse spicules are placed perpendicularly on the primary fibres, but otherwise without regular intervals, they do not form continuous fibres. In the skeleton a distinct but clear and white mass of spongin is found, especially distinct in the nodes. It may in some places be rather copious and entirely coat the fibres, but this does not seem to lie the common case. In the stalk it is more copious, here it coats the fibres entirely, and is of a yellowish colour. Spicula: a. Megasclera are oxea, divided in two rathei distinctly separated sizes, oi which the larger ones form the main skeleton, while the smaller ones are found in the dermal membrane. The larger 1 ixea are evenly curved, sometimes the bend is somewhat sharper and locali :ed to the middle of the spicule. The points are evenly pointed and of middle length. The length varies from ca. 0-41 0-55 "-', and the I20 POEIFERA. II. thickness is ca. 0-017 — o-025'nm. Besides a great many much finer, very long pointed forms are found, which pass evenly into the thicker ones, and are, no doubt, developmental forms. The smaller oxea are of a quite similar form as the large ones, they are evenly, rather slightly curved, and have also evenly tapering points of middle length. Their length varies from 0-268 — o-35mm, and the thickness from 0-013 — o-oi8mra. A few intermediate sizes between the two groups may be found. Fine develop- mental forms are also found of the small oxea.1) b. Microsclcra; these are of only one form, isochelse arena tie; they are of a quite characteristic form, the shaft is highly bent, but the curve may otherwise- be somewhat varying; the tooth forms such an angle with the shaft, that a straight line drawn from one end of the shaft to the other will pass through or along the teeth. The tooth is narrowly ellip- tical, and there is a lougish tuberculum broadest downward; the alse are of the same length as the tooth or reach a little farther down, and when the chela is viewed from the side, they end in a round lobe. Sometimes the chela is so highly bent, that the teeth and alse of the two ends meet, and the bend may be so strong, that the teeth and ala; overlap each other. This fact leads then to some irregularity, the teeth are bent each to its own side, and they get a more or less wry form; on the other hand I have seen no coalescing, neither between alse nor teeth; a coalescing may often appear to have taken place, but by a sufficiently exact examination it is seen that the parts only pass over each other, but are not coalesced. Tog-ether with the strong- bend an alteration of the dimensions of the single parts of the chela takes place; both ake and tooth become longer, and from the tuberculum a continuation reaches farther down the tooth. This irregularitv of the chelae may in some individuals be of frequent occurrence, so that by far most of the chelae are irregular, while in other individuals it is far more scarce. The length, which is a little dependent on the curve, varies between 0-030 and o-04m"', and the thickness of the shaft is 0-0033 — o-oo4mm. Developmental forms of the chelae are rather frequently found, the youngest forms are fine and have rather short recurved ends; at this stage they may to some degree remind of sigmata; by and by tooth and alse are developed. The chelae are found throughout the tissue, but are specially numerous and very close-lying in the dermal membrane. Embryos. In one of the specimens embryos were found abundantly. They are scattered in the tissue, and each of them is surrounded by a thin membrane. They are about globular, and have an average diameter of about o-47mm. The examined ones showed no spicules. As I have had one of Armauer Hansen's type specimens, I have been able to identify the species with certainty; otherwise the determination would have been impossible. The D. clavellata established by Arnesen I.e. I have, likewise by examination of a type specimen, been able with cer- tainty to identify as flabelliformis. Arnesen evidently has only had young specimens; to be sure she states the size to be 25'"', but the specimen sent to me is only 25mm, and the figure of the stalk on Taf. IV, Fig. 4 shows that it is at most a few millimetres thick, so that there can scarcely be any doubt that 25°'" is a misprint for 25""". Locality: The Ingolf, station 7, southeast of Iceland, 63° 13' Lat N., 15° 41' Long. W., depth 600 fathoms, two large specimens; station 85, southwest of Iceland, 630 21' Lat. N., 250 21' Long. W., depth ') I" the mentioned smallest .specimen the spicules were a little smaller, the skeletal spicules measuring at most mil the length of the dermal spicules keeping near the lower limit. The microsclera, on the other hand, were of full size. PORIFERA. II. I2j 170 fathoms, the .smallest .specimen; it was attached to a stone together with a great main sponges of the genera Myxilla, Hymedesmia, Grayella, Hymeraphia, Plocamia, Bubaris , and Latrunculia. It has further been taken northeast of the Faroe Islands, 62 29' Lat. N., 5 tf Long. W., depth [60 fathoms, a small specimen (Ad. Jensen, the cruise of the Michael Sars 1902). Geogr. distr. By the Norwegian North-Atlantic Expedition the species was taken west Spitzbergen, depth 416 fathoms. Aruesen I.e. mentions it from Bergen, at depths of 50 60 fathoms 2. H. palmata Johnst PI. XIII, Fig. 6 a— c. ? 1767. Spongia bacillaris Linne, Syst. Nat. Ed. XII, I, 1299, 13. ? 1 776. — Miiller, Zool. Dan. Prodr. 256, 3086. ?i7S6. Spongia palmata Ellis and Solander, Nat. Hist, of main cur. and iinconi. Zoophytes, fig. 6. 1797. Spongia digitata Esper, Fortsetz. der Pflanzenthiere I, 190, Spong. Tab. L. 1842. Halichondria palmata Johnston, A History of Br. Spong. and Lithophvt. 92, 1, PI. II, figs. 1 5. 1866. Isodictya palmata Bowerbank, Mon. Brit. Spong. II, 311, 25. 1870. Pachychalina compressa O. Schmidt, Grundziige einer Spongieiif. des atlant. Gebiet. 37. 1870. Homoodictya digitata Ehlers, Die Espersehen Spongien, Erlangen, 16, 32. 1S74. Isodictya palmata Kowerbank, I.e., Ill, 133, PL EII, figs. 1 — 7. 1879. Verrill, Preliminary check-List of the Marine Invert, of the atl. Coast fr. C Cod to the Gulf of St. Lawrence, 31. 18S2. Chalina palmata Carter, Ann. Mag. Nat. Hist. Ser. 5, X, 109, fig. i,a,b. 1896. Homoodictya palmata Lambe, Trans, of the Roy. Soc. of Canada, Ser. 2, II, Sect. 4, [90, PI. II, figs. 1, 1 a — f. Of Chalina-likc appearance ; erect, more or less regularly digitately branched, the brandies more or less, often highly, compressed, frequently to a larger or smaller extent coalesced In plate-shaped parts. The surface finely and densely shaggy from Hie projecting ends 0/ the fibres. The dermal membrane a tliin film resting on the skeleton below and pierced by the ends of the fibres. Oscula partly scattered, partly placed along the edges of the compressed brandies or chiefly on one sid<- of them. The skeleton constructed as in Chalinins, forming a regular reticulation of polyspicular primary fibres bena rrds /lit surface in a sheaf-like way, and secondary fibres perpendicular on the primary ones, the niei quadratic or rectangular. Tin fibres provided with a distinct sheath of spongin. Spicula: Megasclera o.xea ovj — o'22pmm; microsclera el one form, isochela palmata- with the axis bending out as a projection from tlii' inside of tin- tooth 0'02^ — 0'0j""". The common exterior form of this species is well known, and it has often been figured, i eiallv, however, in earlier works. It has attracted the attention at an early period, and its extei has given rise to the name of Mermaid's glove , In which it is said to be designated b) the fisher- men of the Orkneys and the Shetland Islands; however, it certainh shares this name with the digi- tatch branched forms of I'aeliyclialina. In its exterior and otherwise also in its skeletal structure i The [ngoIf-E Kpeditioi . \ I [6 I22 PORIFERA. II. -hows great resemblance to Chalinince, especially to such forms of Pachychalina as the mentioned ones. This resemblance is very great and is also found in the form of the megascleres, so that, properly speaking, it is only by the occurrence of the characteristic chela that it can be decided, whether a specimen belongs to a Hbmceodtctya-species, and confoundings have certainly now and then taken place. In the form a frequent feature seems to be that a compression of the branches takes place, and that larger or smaller portions of the lower part of the sponge form flat parts only branching above or in the edge. This form seems to be rather constant in the species, and to stand somewhat opposed to the common form of the Pachyckalina-STpecies most resembling it. This difference is « specially found as a rule, but not always, between the present species and the PacAycAalina-spedes [P. excelsa Schmidt) most common in the North-Sea. Of the species we have a rather considerable material showing the variations of the form. A few specimens have a regular digitate form with only a slight compression of the branches, especially in their lower part, while their upper end is cylindric or almost cylindric. Several other specimens are less regular, with more compressed branches and more expanded parts below, or the expanded parts become larger, and prevail almost over the in this case shorter branches; finally we have one specimen, the branches of which are exceedingly flattened and are King in one plane, so that this specimen gets a very great breadth. The smallest and youngest specimens are quite unbranched; and these small specimens are most frequently formed as a single compressed branch or about oar-shaped, but irregularities may also occur at an early stage, so that the smaller specimens form broad, flat, somewhat lobate bodies. The smallest one of all the specimens, which is attached to a stalk of a Hydroid, is almost globular. Sometimes the lower part is more or less marked off as a stalk, but the branching ma}- also begin directly at the base. Most of the speci- mens are torn off from the underlayer, of the others one is attached to the shell of a Modiola modiolus, a few others partly to worm-tubes, partly to stalks of Laminaria. The number of branches is very varying; the most richly branched specimen is above divided into about a dozen branches, but gener- ally the number is smaller. The largest specimens are 34cm high, and the regular, digitate branches have an average breadth of about 25"™; then follows a series of specimens of decreasing sizes. The largest of the smaller, unbranched specimens has a height of I3CT", and the smallest one is /"5cm high. The mentioned, still smaller, globular specimen has an extent of only 8mm. The consistency is very elastic, quite as in the Chalina. The colour (in spirit) is generally light yellowish gray. The surface is finely and densely, but quite short shaggy from the projecting ends of the fibres. The dermal membrane is a thin and transparent film; it has no spicules, but rests on the skeleton beneath and is pierced by the ends of the fibres. The pores are found in the dermal membrane, often so closely placed that the membrane is reduced to a network; they are round or a little irregular and were measured to a diameter of 0-03 — o-i2mm. Oscula are circular or, more rarely, somewhat oval openings; they are surrounded by a projecting, more or less pronounced, conical edge. They are directed some- what upward, and consequently the projecting edge is higher on the lower side of the osculum. The principal canal runs obliquely downward, but larger canals may frequently be seen to lead into the principal one from different sides. Oscula vary in size from 6mm quite down to imm. They occur in rather large numbers and are found from the very base of the sponge to the top of the branches. Sometimes they may be said to be scattered, but most frequently their occurrence is limited to definite PORIFERA. II. I2, places. Thus they are often found on the edges of the compressed branches, but most frequently some of them are then found scattered on the surfaces. In the highly flattened specimen mentioned before the\- are found, partly on the edges, partly rather abundantly scattered over om surface, while on the other surface only quite few are found; and they may, in the regularly digitate specimens, be found almost exclusively on one surface. The skeleton is constructed quite as in a Pachychalina. It consists of polyspicular fibres passing upward from the base and the middle, branching and bending to all sides in a sheaf-like way, and going to the surface. These primary fibres are connected by transverse fibres that arc placed perpen- dicularly on them but form no coherent fibres. Thus a regular net of meshes is formed, which is only less regular in the middle part of the body. The meshes formed by the fibres arc quadratii rectangular; towards the surface the transverse fibres are placed considerably more closely than farther in. The distance between the primary fibres may be somewhat varying, and was measured to ca.018 — 0'4mi". The thickness of the primary fibres is generally about croc/""'. A distinct and most frequently rather thick sheath of spongin is always found round the needles both in the primary fibres and in the transverse ones. In the points of the fibres the mass of spongin is slight and forms no sheath; this fact is especially distinct in the points of the branches, where the growth more particularly takes place. Quite as in the Ckalinince, layers are also here found in the branches, which layers arc mon less parallel to the surface, and quite recall the structure of the outer skeletal layer, and these layers have presumably during the growth of the sponge marked the close of a period of growth. The layer arises by the fact that transverse fibres are here placed opposite to each other through the whole extent of the layer, while these fibres on both sides of the layer, as well outside it as inside it, are placed more scattered, often with rather long intervals. Then small short, primary fibres are found reaching from the layer of transverse fibres a little outward between the primary ones, but continuing no farther. Thus it looks, as if, by the beginning of a new period of growth, only sonic of the primarj fibres that project through the surface continue the growth. Roth the mentioned structural features cause the mentioned layers to appear as layers of more dense consistency, when a dried specimen oi the sponge is seen towards the light. Already Bowerbank mentions this feature, I.e. II, 312. Scat- tered spicules are found rather copiously outside the fibres. Spicula: a. Megasclera are oxea; they arc straight or slightly curved, and evenly, middle long or rather long pointed. The spicules are very varying, both in length and thickness; the length varies from about 0-15— o-22o,n"", and the thickness from about 1 >•< ©8— inn 7""". The largest spicules are oi most frequent occurrence. It is, however, difficult to give the lower limit of the thickness, as some developmental forms are found passing evenly into the Eullj developed needles. With regard to the size of the needles, especially the thickness, some slight difference may be found between different individuals. Styli are not rarely found between the needles; the) are always shorter than oxea, and they must surely be regarded as monstrous forms; in some individuals the\ are found more frequently than in others, b. Microsclcra; these are onlj of cue form, isochelse palmatce of the peculiar type before mentioned. When the chela is seen in profile, it looks as if the end of the tooth was split into two branches, one of which continues towards the axis. The innei branch is the end ol the axis of the chela, which bends out from the tooth and in towards the axis. When the chela is s ._, , PORIFERA. II. from the front, therefore, a Little below the oblong tuberculum proper another oblong, tubercle-shaped body is seen, which is the translucent, recurved end of the axis. The ake form together an oval plate, and their edges are a little refolded. The plates formed by the alse of both ends continue along the axis as a most frequently quite narrow ridge, and this part arches somewhat out from the axis behind, m> that the back side of the chela is somewhat curved, although the axis is straight. When the chela is seen in profile under strong light, the axis may distinctly be followed, as it is more transparent than the tooth and ake, which are seen from the edge. Then, in the first place, the inward-turned terminal part of the axis is distinctly seen, next a part appearing as a hump on the outside of the tooth, and finally the middle, straight part of the axis (PI. XIII Fig. 6 b). These features are not always easily seen in the fully developed chela, especially as the different parts of the axis are differently developed; thus the falx is rather broad, and the inward-turned terminal part grows often very thick. Otherwise, with regard to length and form of this part, the chela may be rather varying; sometimes, also, the axis, and consequently the whole chela, is somewhat curved. The thin ridge in the middle of the chela may vary to some degree in breadth. The length of the chela varies from 0-024 — o-03mm, and its greatest breadth is ca. 0-007 — 0'Oo8mm. Developmental forms of the chela in all stages occur rather frequently; the finest ones consist only of the axis, which, according to what has been stated above, is straight and recurved at either end in such a way as to form an eye turning to one side; then the alae and the plate of the tooth are formed by and by. The chelae occur both scattered in the tissue of the sponge and in the dermal membrane, but upon the whole in no large numbers. Bower bank's description and figures of this chela are quite incomplete; thus his figure of the profile does not show the peculiar continuation of the axis, but the chela is, however, tolerably recognisable, especially from the figure showing it from the front. His description, on the other hand, is quite erroneous. Carter 1. c. gives a good figure of the chela seen as well from the side as from the front, but in his description there are several misconceptions. Ridley and Dendy (Challeng. Report, 108) say, in their description of the chela in the generic diagnosis, from the median line of the posterior surface of each anterior palm there projects backwards, i. e. towards the shaft, a delicate, flat fimbria ; according to this expression these authors do not seem to have seen that the question is of the axis of the chela; neither is it correct, when they term the inwardly-directed process delicate, flat , although, to be sure, it is frequently somewhat compressed. Also their figures of the chela, especially in the species grandis, show that the process is here quite cylindrical. Locality: From Iceland and the Faroe Islands we have a rather considerable material. From Iceland: .Skagen (Gronlund), off Rodsauds Bay (Hj. Jensen), Onuudarfjord, depth 10 fathoms (the author); Iceland, no more particular locality stated (Jap. Steenstrup, Halberg). From the Faroe Islands: 6 miles N.W. of Kalsc">, depth 60 fathoms, Vestmansund, depth ca. 70 fathoms, 9 miles east of Nolso, depth 30 fathoms (Th. Mortensen) ; the Faroe Islands, no more particular locality stated (Nees, Rostrup, Midler). Seventeen largei and smaller specimens in all. Geogr. distr. North-England, Scotland, the Shetland Islands and the Orkneys (Johnston, Bower- bank); Norway (Esper, Ehlersl. c); New Scotland, Sable Island, and the Bay of Fundy (Lambe); between Cape Cod and the Gulf of St. Lawrence (Verrill). Thus the species is distributed between ca. 66° and PORIFERA. II. I2S 44 Eat. N., but on the eastern side of the ocean it is known no farther south than to the coasl England. It is not found in deep water, the greatest depth known being ca. 70 fathoms. Remarks to the synonymy. This species is generally enumerated as palmata Johnst, and Carter (1. c.i having examined Johnston's type specimen and found the characteristic chela, the identification may also be regarded as sure. The species may, however, with certainty be traced farther hack. Killers (1. c.| having shown by examination of Esper's type specimen of Spongia digitata that this species is identical with Johnston's palmata, what was also indicated by Esper's figure. Therefore there might be some reason for taking up Esper's name of digitata, which dates from 1797. I have not done so, however, as there is great probability that Spongia palmata Ellis and Solander, [786, is the same species. The description, to be sure, gives no hold, but the figure of the exterior, showing the characteristic compression, seems to show, even if not quite certainly, that the question is of the present species. Linne's name of Spongia bacillaris, on the other hand, cannot be taken up, as it is impossible to decide, whether he lias had before him the present species or some Pachychalina-iovxa. By the examination of Schmidt's type specimen of Pachychalina comprcssa I have been able to decide that this species is identical with H. palmata, as already mentioned in part I of the Porifera of the Ingolf-Expedition, p. 6. Group 2. Myxilleae. Megasclera generally divided into two forms, those forming the dermal skeleton, ami those forming the main-skeleton. Typically the skeletal spicules are monaetinal and the dermal spicules iliactinal, but exceptions from this rule occur. It seems to be a rather important character of the group Myxillece that the skeletal spicules are of one form and almost always monaetinal, the dermal spicules of a different form and most fre- quently diactinal. The reach of this character, however, cannot yet be decided. In the group Mycalcct, to lie sure, instances may be found where the spicules that in some way or other belong to the dermal membrane are smaller or of a form somewhat different from those of the principal skeleton, for instance M. placoides, some Esperiopsis-species, Artcmisina, Homorodictya flabclliformis, but they are generally of the same type. In the following subfamily, Ectyoninm, which is closely allied to Myxilleer, on the other hand, some genera are still found showing the difference, characteristic of Myxilleer, between the dermal spicules and the skeletal ones, and still here the system is scarcely a natural one. The dermal spicules in Myxillece. are generally briefly stated to be diactinal; this statement, however, is not quite correct. As will be mentioned m the following under the single species the equi-ended dermal spicules, whether they be strongyla, tornota, or tylota, are only secondarily diactinal, but really monaetinal, as they are begun as monaetinal and grow as such to about their full length, and then the final form only occurs by degrees, contemporaneously with the growth in thickness. In the not quite developed spicules this development max still be traced, the ends being not quite equal, and it is no rare fact that the ends upon the whole never become quite equal, but it may still be decided in the fully developed spicules, which end has been the original point. The general tact is, accordingly, that the finer, i.e. the younger, the dermal spicules are, the greatei is the difference I26 PORIFERA. II. between tlieir ends, and the more they approach the monactinal form. This rule seems to be a gener- al one; it is to be noted, however, that in the new genus Dendoricella established below, the dermal spicules are really diactinal. I have not yet been able to decide, whether these features may get any systematic importance. It is, accordingly, to be remembered that when in the following the dermal spicules in diag- nosis and description are called diactinal, this term is a purely descriptive one and means only that in tluir final form the spicules are more or less equi-ended. Dendoricella n. or. (Damiria Topsent). The form massive, lobate or erect, club-shaped. The skeleton polyspicular,. irregular or dendritic; I he dermal skeleton consists of more or less erect bundles of dermal spicules. Spongin present or wanting. Spicula: Megasclera: 'the skeletal spicules diactinal, oxea (or strongyla), the dermal spicules oxea, tornota, or tylota; microsclera chela arcuatce solely, or chela arcuatce and sigmata. Topsent (Archiv de Zool. exp. et gen. Ser. 2, X, XXI) mentions the genus Damiria Keller, and characterizes it as being distinguished from Den dory x (in Topsent' s sense) by its diactinal skeletal spicules. Later has for instance Lindgren followed Topsent in this view. Weltner, however, (Zool. Anzeig. XXI, 1S98, 429) has shown that Damiria Keller has by its author been correctly referred to the Renierids, and has nothing to do with the Myxillse, and after having examined a frag- ment of the type specimen kindly sent me by Dr. Weltner I can only corroborate this view. For the generic conception which Topsent in the quoted place calls Damiria we must thus have a new name. Ridley has referred a species belonging here to the genus Crella Gray {Cribrella O. S.), but Thiele (Kieselschwamme v. Ternate II, Abhandl. d. Senckenberg. nat. Gesell. XXV, 953) has correctly rendered an account of the fact that the type of this genus, C. elegans O. S., is a quite different sponge. Thiele means, in the place quoted, that the species belonging here may be kept in the genus Myxilla, whereas my opinion is that it is necessary to place them in a separate genus with the diag- nosis given above, and I call this genus Dendoricella. Its most important character is that the skeletal spicules are plainly and really diactinal. The eldest species of the genus is D. Schmidtii Ridley (Zool. Coll. of « Alert , 432, PI. XLI, fig. aa). Dendy has later (Proc. of the Royal Soc. of Vict. VIII, 28) established a species, D.australiensis, which is. however, according to Topsent (Rev. Suis. de Zool. IV, 455) identical with Schmidtii. Topsent, in 1892, (Archiv de zool. exp. et gen. 2, X, XXII) has established two species (under Damiria), caver- nosa and Prouhoi; of these species the latter has certainly not really diactinal spicules, but is, no doubt, a Myxilla (see below under M. brunnea); the former species, cavernosa, I think to be a Dendo- ricella. Finally Topsent (Resultats de Campagn. scient. du Prince de Monaco, Fasc. XXV, 240, PI. Ill, fig. 3, PI. XIV, fig. 12) has established a species, abyssi, which, remarkably enough, he refers to Dcsma- cidon, although it is a sure Dendoricella. Of Carter's Halichondria infrequens (Ann. Mag. Xat. Hist. PORIFERA. II. j2- Ser. 5, VII, 309, PL XVIII, fig.ga— d) nothing can be said at present, and it is very doubtful whether it belongs here. Thus the species of the genns Dendoricella will be as follows: [884; D. (Crella) Schmidtii Ridley, with oxea, tylota, chelse, and sigmata. 1S92. - (Damiria) cavernosa Tops, with strongyla, tylota, chelse. (Of what kind these chelae are can- not be decided from the description, in which it is said a bouts pectines .) 1903. - (Desmacidon) abyssi Tops, with oxea, tornota, chelae. rhopalum n. sp. with oxea, tornota, chelae. - obesichela n. sp. with oxea, oxea, chelae, and sigmata. The Myxilla grata established by Thiele I.e. has evidently, to judge from the figure, not really diactinal skeletal spicules, but styli with rounded end, and is either a Myxilla or perhaps a I.is- sodendoryx in the sense in which I take this genus; the fact is that it cannot be seen from the figure, whether the species lias chelae or ancone. When Ridley referred the species Schmidtii to Cribrella = Crella, the more particular reason was, I suppose, the arrangement of the pores in sieves. Characteristic as this feature may be, it is a character that is found in many sponges, and cannot be used for an establishing of genera; it i^ only a further development of the feature found in a great many sponges in which the pores are especially placed over the subdermal cavities. Of Schmidt's four Cribrella-species hamigera is now the type of the genus Hamigera; elegans, which has smooth oxea in the principal skeleton, spined oxea in the dermal membrane, and further spined styli, I suppose to be identical with Topsent's genus Pytht is, in which case this genus may be called Crella; hospitalis and papulosa, as mentioned by Topsent, belong to the genus Yvesia Tops., which genus, what Thiele has drawn my attention to, must he- called Grayella Cart, with the typical species cyatophora Cart. - < >f the Dendoricella-spedes rhopalum shows the mentioned character of sharply limited pore-grooves to .1 strongly marked degree; the structure seems to be rather similar in abyssi and Schmidtii, but it is not mentioned with regard to (in'rniosa. The two species described here, and abyssi are natives of deep waters, from 799 fathoms; Schmidtii and cavernosa, on the other hand, are from shallow water. The genus Dendoricella must among Myxillea be the one most closely allied to the preceding group, as it approaches Homaodictya; among the f/omojodictya-species a lew are found, in which the spicules of the dermal membrane are smaller than those of the skeleton, but they are of one form; in Dendoricella, on the other hand, two forms are found. 1. D. rhopalum n. sp. PI. IV, Figs. \ 5. PI. XIV, Fig. 1 a-e. Club-shaped, often wmewhat compressed, sometimes u little lobate above. '/'/.> vith close- w /. more or less drip grooves, separated by ridges arranged in a net-like way, slightly shaggy. The tin- mat membrane a thin film, supported by bundles oj dermal spicuL • :pout-sha/ one or several, on tin upper part of the sponge. The skeleton dendritic, polyspicular. Spicula: M . [28 PORIFERA. II. sclera: the skeletal spicules oxea o-68—o-p8mm, the dermal spicules tornota approaching oxea om4^—o-6f"m; microsclera of one form, isochela arcuata 0-034 -"'"•/- <>"""■ This species is most frequently markedly club-shaped. The specimens in hand that are not torn off from the under-layer are attached to larger or smaller stones. At the place of attachment thev have a quite slight basal expansion, from which they rise increasing more or less evenly in thickness; thus no real stalk is formed, but the thinnest part is always found just above the basal expansion. Sometimes the upper part is more or less regularly cylindric like the lower part, but most frequently it is more or less compressed, sometimes in such a way that one side is convex, the other flat or concave. Most frequently the club-shape is rather slender, but it may be shorter and thicker. In a few cases the form is a little modified, the upper part being a little lobate; thus we have one specimen, which is, almost through its whole length, divided into three wing-like lobes. In one case the club is divided above into four quite short processes provided with oscula. The largest specimen is ca. gomm high; it is compressed, and has a breadth of ca. 50mm, and a thickness of ca. I2mm, just above the basal expansion the thickness is ca. iomm. The smallest specimen, which is more cylin- drical, is 24""" high and 7mm thick. The consistency is rather firm and, on account of the skeleton, rather solid, and it is also somewhat elastic. The degree of contraction of the sponge causes, however, a considerable difference with regard to the consistency, the most contracted ones being considerably harder than those not contracted. The colour (in spirit) is in most specimens light gray (stations 20 and 36); in some specimens it is a little darker with a brownish tint, so that it becomes light grayish brown (station 18). The surface is very characteristic, but it has a rather different appearance, accord- ing as the sponge is contracted or not. Its appearance is most characteristic in the highly contracted individuals; in these it is closely set with rather deep grooves separated bv narrow, ridge-shaped walls; these walls form a peculiar net all over the sponge, imparting to it an appearance highly recalling that of Nardoa reticulum. The less contracted the sponge is, the flatter these grooves become, and thev may also quite disappear. The grooves are nothing else than those occurring in so many sponges, for instance in At. incrustans, which are formed by the dermal membrane being sunk between the parts of tissue separating the subdermal cavities, but the}' are here more regular and always sharply bounded from each other. The less contracted the sponge is, the larger and more shallow are the grooves, while they become smaller and deeper in the contracted sponge, and in this latter they are often oval. Their size is between about 0-4 and 3mm. The grooves, especially in the contracted sponge, have a rather sharp edge. The surface is so far shaggy, as the dermal spicules project a little every- where between the grooves. The dermal membrane is an exceedingly thin, transparent film, resting on the bundles of dermal spicules projecting from the ridge-shaped walls, and stretched over the inter- jacent subdermal cavities. The pores are situated in the parts of the membrane stretched over the subdermal cavities, and these parts are accordingly pore areas; in these areas they are found in large numbers and very close-set, so that the membrane becomes a sieve. Their size was measured to 0-03 — 0,40n"D. Oscula are found to a number of from one to ca. ten, evidently in proportion to the size of the sponge. They are found on the top of the sponge or a little down on the side; the largest speci- men shows ten oscula, but it is somewhat damaged, and has perhaps had more than ten; they are all PORIFERA. II. t2g placed rather close together along the upper edge. In the above mentioned specimen which divides above into four processes, three of these processes have each an osculum, while the fourth one has two oscula. Oscula are spout-shaped, a pointed, conical spout rising to a greater or smaller height round the opening, which spout is formed by the dermal membrane; it is most frequently somewhat twisted. In the membrane forming the spout dermal spicules are found, arranged parallelly to the longitudinal axis of the spout, more or less gathered into fibres; these fibres arise from the fil supporting the dermal membrane, which continue into the membrane forming the spout From the oscular opening a rather wide canal continues far down in the sponge, running chiefly in the longi- tudinal direction, but frequently irregularly curved. The skeleton. The dermal skeleton. The outermost branchings of the main skeleton towards the surface are continued by short fibres of dermal spicules. The outermost spicula-bundles of these fibres are spread in a penicillate or fan-shaped way, and they extend everywhere into the ridges between the pore grooves, and project a little over the surface; horizontal spicules are not found, and the fibres are arranged in such a way as only to be found in the ridges. In different places of the sponge these fibres may be differently directed, perpendicular to the surface or more or less recumbent; thus they are frequently directed towards the upper end of the sponge, and accordingly recumbent, when a piece of the membrane is seen from above. The fibres formed by the dermal spicules are must frequently about imm long. The arrangement of the dermal skeleton reminds much of the structure in Arteinisina arcigera. The main skeleton is of dendritic tvpe. From the base a few thick fibres rise, branching grad- ually up through the sponge, frequently coalescing and connected by more or less strong anastomoses in different ways, so that a chiefly dendritic, tolerably regular and rather densely branched skeleton is formed. The outermost ramifications of the skeleton bend towards the surface at right or more or less acute angles. Then these outermost ramifications of the skeleton, as mentioned above, continue to the surface as fibres formed by dermal spicules. All the fibres are polyspicular, towards the base they may be very thick, up to o-5mm, and they are here interwoven with a network of more or less strong anastomoses. The outermost ramifications, just before the beginning of the dermal spicules, have a thickness of ca. o-oo,mm. Spongin is found in the fibres, which are, therefore, very solid, but the spongin is white and clear, and so it is only to be observed with difficulty. In the lower part of the sponge it coats the fibres entirely, but only with a very thin layer; farther up the spongin is more scarce, and it is not seen in the dermal fibres. Spicula: a. Megasclera. i. The skeletal spicules are long oxea; they are slightly, rarely a little more, curved; the curve is most frequently even, sometimes it is a sharpei bend and localized in the middle. The spicules are of about equal thickness throughout the length, and the point is middle- long, frequently bounded by straight lines. The length is o-68 o^S"™, most frequently nearer to the latter limit than to the former; the thickness is 0-014 ■■ . A few developmental forms are seen, all of which are long pointed. 2. The dermal spicules may be best described as tornota, but the) approach the form of oxea; they taper a little from the middle outward, the point may be somewhat varying, but most frequently it is short. They are generally straight, sometimes a little curved. Then length is 0-45 0-65mm, their 'thickness ca. our .nui1™. Of this spicule very few developmental tonus were seen, and no quite young ones. But to judge, both from the quite equally formed ends of the The rngolf-Expedition, VI. -■- PORIFERA. II. fully developed forms and from the few developmental forms, this spicule seems to be really diactiual b. Microsclera; these are only of one form, isochelse arcuatae. The chelae are elegantly formed, the shaft is evenly and rather highly curved, the terminal parts are comparatively small in proportion to the length of the chela. The alse are drawn out to a pointed corner, and are somewhat tooth-like; the tooth is narrowly lanceolate, pointed downwards, and there is a small, oblong tuberculum. The shaft is not quite cylindrical, but a little compressed; this compression maybe more or less pronounced, and the dorsal side of the shaft may thin to a more or less broad brim. In this respect there may- be great difference in different individuals. In some individuals the shaft is only little compressed, and only very few chelae show a slight brim; in others chelae with brim and without brim are about equally frequent, and in one specimen almost all the chelae have a brim, and only few are found without brim. The more frequent the chelae with brim are, the broader is the brim. In the specimen in which almost all the chelae are provided with a brim, this brim has frequently one or two incisions, so that it is divided into two or three lobes. In by far most individuals the brim is narrow, and in most of the chelae it is wanting, so that it seems as if its higher development is to be regarded as a monstrosity. The length of the chelae is 0-034— o-c>429mm, and the thickness of the shaft is between 0-0014 and o-oo29mm, according as it is seen from the front or from the side; in chelae with large brim the breadth of the shaft may reach 0-0050""". A few developmental forms were seen; the fine ones had a recurving at either end, but did not yet show any traces of alae. The chelae are found through- out the sponge, and they are abundantly present everywhere in the dermal membrane, besides in other places they are close-lying in the pore sieves in the strings of tissue between the pores. Locality: Station n, 640 34' Lat. N., 310 12' Long. W., depth 1300 fathoms, one specimen; station 18, 6i° 44' Lat. N., 300 29' Long. W., depth 1135 fathoms, three specimens; station 20, 5S0 20' Lat. N., 40° 48' Long. W., depth 1695 fathoms, six specimens; station 36, 6i° 50' Lat. N., 560 21 Long. W., depth 1435 fathoms, ca. ten specimens. The stations are situated in the Denmark Strait, south of Greenland, and in the southern part of the Davis Strait. The species is evidently a deep-water species, 1135 fathoms being the smallest depth, at which it has been taken. All the specimens are more or less, some to a very high degree, filled with the light-gray mud of which the bottom at the mentioned localities consisted; in it is found a great many Foraminifera and Coccoliths. This filling may, however, at all events partly, have taken place in the trawl. Remarks: This species seems to be rather closely allied to the above mentioned D. abyssi Tops, whose chelae, to judge from the figure, have a somewhat similar form, and whose dermal spicules are tornota. Also this species* is a native of considerable depths, between ca. 2000 and 2500 fathoms. Top- sent mentions that it, like rhopalum, contained much bottom material. 2. D. obesichela n. sp. PI. XIV, Fig. 2a-d. Form? The dermal membrane thin, supported by bundles of dermal spicules. Spicula: J/ega- sclera: the skeletal spicules oxea 0-5./— 075""". the dermal spicules oxea 0-32— o-^"""; microsclera of two farms, chela- arc/tut, e 0-026— o-o42g""", sigmata 0-021 — 0-064""". PORIFERA. II. r, j Of this species we have only a small, poor fragment, .so that the description must chiefly be restricted to the spicules. As to the form of the sponge nothing ran be said; the fragment is Longish and has a greatest extent of i4n,n'. The consistency is of a middle firmness. The colour (in spirit) is yellowish. The dermal membrane is mostly destroyed; it seems to have been a thin film, supported in the common way by dermal spicules. Pores and oscula were not seen. The skeleton. The dermal skeleton consists of dermal spicules, and, in spite of the destroyed dermal membrane, it may be seen to have been arranged in the common way as more or less erect, penicillate bundles. As to the main skeleton, on the other hand, I can say nothing definite, as the fragment in hand may perhaps have been highly squeezed and pressed; in its present state the skeleton appears partly as irregularly arranged spicules and partly as spicula-bundles. No spongin was to be seen in the skeleton. Spicula: a. Megasclera. r. The skeletal spicules are oxea; they are slightly curved, evenly tapering, and the point is rather long. Their length is 0-54— c>75mm, the thickness is ca. 0"i >i 1 — 0-017""". 2. The dermal spicules are also oxea, but by the form of their ends they approach somewhat to tornota; they are straight or quite slightly curved, and they taper a little towards the ends, the point is even, but short. Their length is 0-32 — 0-44""", and the thickness in the middle is o-oo6— ooiomm. b. Microsclera; these are of two forms, chelae arcuatse and sigmata. 1. The chelse arcuatse are of a rather broad and compact form, the shaft is rather highly curved, the tooth is elliptical, more or less rounded, sometimes a little cut off at the end; there is a tubereulum, pointed downward; the ake are of the same length as the tooth, and are more rounded. In contradistinction to the chela of the preceding species the shaft is here highly flattened. Their length varies from 0-026 — oro^20j!am and the thickness of the shaft from 0-0025 — 0-0085""", according as it is seen from the side or from the front. Very few developmental forms were seen; they are already' highly flattened at an early stage. 2. Sig- mata; these are of the common form and more or less contort; their length may upon the whole- vary from 0'02i— o-o64mrn, but it is rarely less than 0-043""", so that the small forms are rarely seen. The thickness is upon the whole 0-0014 — 0-0028""". Both forms of microsclera occur in very large numbers, and through the whole sponge; the chelae are seen in enormous numbers closely packed in the dermal membrane. Locality: Station 78, 60° 37' Lat. N., 27" 52' Long. W., on the eastern slope of the Reykjanaes- ridge, depth 799 fathoms. Myxilla ( ). Schmidt. (Dendoryx Gray 186 The form varying, from incrusting to lumpily massive, cushion-shaped, or form it, round masses, sometimes somewhat lobate; then more or less irregularly leaf-shaped, or finally club-shaped, stalked. The skeleton a polyspicular reticulation, which may be more or less irregular, somettm, 1 diffuse. In the erect forms longer, primary //Ires an found. It is no rare form that the reticulation el triangular meshes, which max be more or less regular. The derma/ skeleton red bundles of dermal spicules, sometimes also horizontal spicules arc found. Spongin is found, but almost ah , ,2 PORIFERA. II. to a very slight amount. Spicula: Megasclera: the skeletal spicules styli, most frequently spined, sometimes smooth, the dermal spicules diactinal, strongyla, tornota, tylota, or similar forms, the ends may be vari- ously formed, and spined or smooth; microsclera, ancorer spatulifcrcr, sometimes of two forms, most fre- quently three-toothed, sometimes with more teeth : further sigmata may be added. In 1S62 O. Sch mid t established the genus Myxilla with the species rosacea Lieberkuhn. In 1867 Grav established the genus Dendoryx, and as the first species under it he mentioned incrustans Johnst. In 1SS7 Yosmaer, in Porifera, Bronn's Klassen und Ordnungen , has the families Dcsma- ■ nidce and Ectyonidm, and he places Myxilla to the former family, and has Dendoryx with a query as a synonym to Hastatus, which, as is well known, is identical with Myxilla. In the same year Ridley and Dendy in Challeng. Report, under the family Dcsmacidouidcc, have the subfamilies Esperellince and Ectyoniniz, and here they place the genus Myxilla to the latter subfamily. They render a detailed account of the fact that the genus comprises as well species with accessory spicules as species with- out such spicules, but they have not wished to divide the genus. In 1S8S Top sent (Arch. de. Zool. exp. et yen. Ser. 2, V, bis, 114) revives Gray's Dendoryx, and in 1892 he places the species without accessor)- spicules in Dendoryx , while he places the species with such spicules in Myxilla. Then Dendoryx is placed under Esperellince and Myxilla under Ectyonina. Thiele, however, in 1903 (Kieselschwamme von Ternate, II, Abhandl. der Senckenberg. nat. Gesell. XXV, 953) renders an account of the fact that the genus Dendoryx, as Topsent understands it, ought to be called Myxilla, as the typical species of Myxilla, rosacea Lieberk., according to Topsent (Mem. de la Soc. zool. de Fr. VII, 15, footnote 4) is identical with incrustans Johnst. Even if this view, as will be seen below, is not correct, the name of Myxilla will have to be used, as rosacea is, at all events, a species without accessory spicules. 1. M. incrustans Johnst. PI. IV, Figs. 6, 7. PI. XIV, Fig. 3 a— h. 1842. Halichondria incrustans Johnston, A History of Brit. Spong. and Lithophytes, 122, PI. XII, fig. 3, PL XIII, fig. 5. 1842. Halichondria saburrata Johnston, ibid. 120, PI. XI, fig. 3. 1866. Halichondria incrustans Bowerbank, Mon. Brit. Spong. II, 249, 14. [870. Isodictya fimbria fa O.Schmidt (non Bow.), Grundziige einer Spongieuf. des atlant. Gebiet. 56. 1 s74- Halichondria incrustans Bowerbank, I.e. Ill, 108, PI. XLJV, figs. 7 — 12. 1885. Myxilla barentsi Vosmaer, Bijdr. tot de Dierk. i2te Aflev., 3die Gedelt, 27, PI. IV, figs. 15 — 16, PI. V figs. 56-59. 1885? Hastatus Robertsoni Fristedt, Kgl. Sv. Vet. Akad. Handl. 21, Nr. 6, 34, Tab. Ill, Fig. 4 a— b. 1886. Desmacidon incrustans Marenzeller, Die osterreich. Polarstat. Jan Mayen, III, 10, Tab. I, Fig. 2. 1887? Hastatus Robertsoni Fristedt, Vega-Exp. Vetensk. Iakkt. IV, 442. 1888. Dendoryx incrustans var. typica Topsent, Arch, de zool. exp. et gen. Ser. 2, V, bis suppl. 118, PI. VI. fig. 16 a. 1890. Dendoryx incrustans Topsent, Mem. de la Soc. zool. de Fr., 201. PORIFERA. II. I3, 1893. Myxilla incrustans Levinsen, Det vidensk. Udbytte af Hauch's Togter, 419, 17. Tab. I, Fig- 31— 34- 1896. Dendoryx incrustans Topsent, Resultats scient. de la Carapagne du Caudan , 274, 15. 1896. Myxilla incrustans Lambe, Transact, of the Royal Soc. of Canada, Ser. 2. II, Sect. IV, 191, PI. I, figs, ro, 10 a — d. Incrusting, forming irregular, massive masses, or being more roundish lumpy. The surface with sinuous grooves, more rarely even, not shaggy. The dermal membrane it thin film supported by penicillate bundles of dermal spicules. Oscula scattered, sometimes on the lap of low cones. The skeleton chiefly a polyspicular reticulation of triangular meshes, sometimes more irregular. Spicula: Mcgasclcra: the skeletal spicules acanthostyli with scattered spines o-/p — o\;y""!, the dermal spicules tornota with slightly spitted, rarely smooth ends o-ij — u-2t>"n"; microsclera oj three forms, ancorm spatitlifcree oj two sizes, largt ones o'OjS — o-oji'"'", small ones o'uiy — 0'028, sigmata o'02/f. — o'oyj""". This species may vary rather much in appearance, and in this respect it recalls Halichondria pauicea. As in this species, however, the form is highly dependent on the substratum on which the sponge is growing. The most frequent forms are more or less extended, incrusting masses that may be thinner or thicker; then it may rise to cushion-shaped bodies or to irregular, roundish lumps. When growing on Algae, roots of Alga; or similar bodies, ii may have a quite irregular form, but then it is most frequently only incrusting. Oscula may sometimes be found on more or less distinct, conical projections on the cushion-shaped or lump-shaped sponge. The species seems sometimes to be growing directly on the sea-bottom; a few of the specimens in hand are not attached, but their basal surfaces are filled with sand and gravel. According to Johnston and Bowerbank, it is also frequently found on rocky bottom, growing on the rock. It is very often growing on Pec ten-species, and then it is most frequently rather regularly cushion-shaped or flatly semiglobular. In the Ingolf-material we have it on Pecten islandicus ; Bowerbank mentions it on Pecten operations, and Lambe has it from the American coast on Pecten tenuicostatus. Levinsen mentions it from Denmark on Mytilus modi and Cyprina islandica. As rather thin, irregular incrustations it is found on barnacles. Bryozoa, worm- tubes, and Laminaria-xoots. The largest specimen in hand, which is not attached, has a greatest breadth of ii5mm and a height of 90"""; most of the specimens are not so large and especiallj not .so high; a middle-large one, growing on a Pecten, is j$mm broad and ca. 25'nm high. The smallest speci- men in hand forms a small crust on a barnacle, it has a greatest extent of o"'" and is only . thick. The consistency is of middle hardness, it is only little elastic and rather fragile. The colour (in spirit) is most frequently light yellowish; in the fresh specimens it is described as yellow to orange. The surface may be somewhat varying; it may sometimes be quite even and smooth, but most fre- quently it is more or less, often highly grooved, and the grooves are separated by winding ami wrin- kling walls. These walls are formed by the parts of tissue separating the canals; these canals are present in large numbers, they run very close to each other, and are most frequently directed towards the surface. Although the dermal membrane, as will be mentioned later 011, is supported by the projecting spicula-bundles, the surface is nevertheless almost smooth, the spicules projecting so little, that thev are only to be observed by means of a highly magnifying lens. When the walls are more PORIFERA. II. compressed and have sharp edges, these edges, however, are most frequently finely spined, which is owing to the skeleton below. The dermal membrane is a rather thin, transparent film. It is supported by bundles of dermal spicules projecting in a fan-shaped way. These spicula bundles, however, are frequently not perpendicularly erect, but more or less, often highly recumbent. Of spicules the mem- brane otherwise has only microscleres. In different individuals, or in different places of one individual, it may have a somewhat different appearance; in more compact individuals with not especially large canals (perhaps more contracted individuals), or in places of the individual showing such a condition, the skin is rather smooth, and the projecting spicula-bundles are here close-set and rather perpendicular. Where the surface is more grooved and the membrane stretched over the grooves, the structure is some- what different, as there are here large parts of the membrane with no skeleton immediately below them, from which the bundles may arise. Then the bundles issuing in a fan-shaped way from the edge reach into the membrane, and are quite, or almost quite recumbent in it, and in the middle part of it, where the bundles do not reach, scattered horizontal spicules are further found. In other places the structure is again somewhat different, fibres running from the skeleton under the parts of the membrane stretched over the grooves, from which fibres fan-shaped bundles project and pass into the membrane where they are more or less horizontal. This latter structure gives to the dermal membrane a peculiar appearance, as the parts of the membrane that are stretched over the canals or the subdermal cavities and, on account of the cavities below, appear as dark areas, are again subdivided by the mentioned fibres, which form a reticulation, in the meshes of which the pores are then situated. The pores are found in the dermal skeleton in the areas formed by the skeleton; they may be present everywhere, but are seen especially numerous and close-lying in the parts of the dermal membrane situated over the subdermal cavities, which parts are here often reduced to a sieve. They are round or oval and of sizes from quite small ones to cvi5mm. Oscula are found scattered in rather slight numbers; as men- tioned above, they are sometimes found on the top of conical projections, but these projections are often quite low or quite wanting. In a few cases the conical projections are not separated, but form a continuous wall with several oscula placed in the edge. This structure is illustrated by Bower- bank's figure PL XLIV, 7. In the largest specimen in hand eleven oscula are found. The appear- ance of the oscula may be somewhat varying; in the more compact forms with even surface the osculum is a regular round or oval aperture definitely bounded by the skin, which rises sometimes to a sharp edge round the aperture. Here the oscula are most frequently small, and were measured down to imm or less. In individuals with highly grooved surface, on the other hand, the edge of the oscula becomes often irregularly indented, so that the aperture is somewhat lobed. It is this structure which causes Johnston to use the expression: «oscula obscure, substellated , presumably the dermal membrane has also been wanting to a great extent, and then oscula are little marked compared to the openings of the inhalent canals. When oscula are of the last-mentioned structure, they are generally rather large, and they were measured up to a diameter of iomm. The skeleton. The deemed skeleton consists, as already mentioned, of perpendicular or more or less recumbent bundles of dermal spicules, which pass off from the main skeleton and support the dermal membrane, and bend as fibres under and into the parts of the membrane stretched over the subdermal cavities. Generally the question is only of bundles; but sometimes, in certain places of the PORIFERA. II. nj sponge, they are lengthened more inward, so as to become short fibres passing out and ending in the dermal membrane. In the ridges of the surface that are more compressed and sharp-edged, the dermal skeleton is often much suppressed, and the main skeleton may continue quite out and give rise to the mentioned small spines. The main skeleton consists typically of triangular or, more properly, tetra- hedral meshes, the sides of which have the length of a spicule and are formed of from one to live or six spicules. It may, however, be somewhat differently constructed in different individuals. Thus more or less marked fibres occur not rarely in larger or smaller numbers; they run especially in the direction towards the surface. When these fibres occur in larger numbers, some quadrangular meshes may be formed here and there, but a regular, quadrangular net of meshes is not formed. The longer fibres are generally a little thicker than the others. In other individuals the skeleton is much less regular and is not formed of so distinct triangular meshes, and then it is upon the whole of a more diffuse character. In the membrane coating the canals only microscleres are found. Spongin is found in the nodes of the skeleton, but it is only to be observed with much difficulty, as it is quite white and clear, and only a minimal amount is present. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli, straight or slightly curved, most frequently with the curve near the upper end; the point is middle long or rather short. Tin spiuulation may be somewhat varying, but is geuerallv rather scattered; the spines are not rarely gathered a little more densely at the upper end; only a short part of the point shows no spines. The styli vary rather much in size, not, however, in one individual, but in different individuals, whereas the variation in one individual is most frequeutlv onlv slight. The length varies altogether from 0-19 — o-35mm; in the single individuals may be found for instance: 0-19— 0'22m,,\ o-2i — o-268""n, o-2;S o-298ram, and 0-28 — o-35'"m. The thickness, which is only partly proportionate to the length, varies alto- gether between o-oo8 and croi5mm. Finer, down to quite fine styli which are certainly developmental forms, occur in most individuals scattered in the tissue. They have about the full length, and their point is long and fine. Among the finest of them some were smooth, but otherwise traces of spinu- lation occur early. In the fine forms the spines are small and especially low, so that these tonus may get an irregular, knotty appearance. In an individual with needles of the greatest lengths given above, the fine developmental forms were measured, for instance, hnr>ir with a thickness of 00028 the very finest one observed was o-ooiom,n thick, and ca. o-i7mm long; in this needle no trace of spiuu- lation was seen. From the finest stages all transitional forms are found to the fully developed needles. 2. The dermal spicules are tornota; they are straight, or at most quite slightly, irregularly curved. They are cylindrical and most frequently slightly fusiform. The ends arc short pointed; often a slight constriction is found below the end; the ends are slightly spinulous, only in a few cases smooth almost smooth. It is to be remarked that the ends of the tornota are not always quite equal, hut one end is frequently a little thinner than the other. Their length varies in a similar way as that of the styli, altogether it is between 017 and <>-2(>""", but in individual specimens it was measured, for instance, to o-ij — o-2o""", 0-19- o-22mm, and <>_m o,26mm. The thickness is 0-0057 o-oirom. Only very few finei forms were seen, and none very line. Microsclera; these are of three forms, three-toothed isano spatuliferse of two forms, and sigmata. 1. The large ancorae have a slightly curved shaft, and in either end three lanceolate teeth; in both ends a rather uarrow ala is found on either side oi the 136 PORIFERA. II. shaft; the alse arc most frequently a little longer than the teeth. The teeth are directed slightly out- ward. The length varies altogether between ca. 0-038 and o-oji™"1; it may vary somewhat in the single individual, not, however, so much. Thus in a specimen with the smallest ancorse the greatest length was o-043mni) and in a specimen with large ancorae the smallest form was 0-059'""' long. The greatest 1th of the ancorse from one lateral tooth to the other is about 0-014— 0'025mm. Besides the length also the dimensions of the different parts may vary; thus alse and tooth may be comparatively longer or shorter, and the free middle part of the shaft may, according to this variation, be from one third to one fifth of the whole length. Of this ancora a few half-developed stages were seen, in which only beginnings of the teeth and fakes were present. — This ancora showed frequently, at all events in main individuals, many different deformities. It has been mentioned that the ancora; may vary some- what with regard to the length of the teeth; also the breadth of the teeth may vary, and they may be very narrow. Then they ma}- be straight cut off at the end, and here they have very often an incision, so that they become more or less deeply split. Further the alee may separate more or less from the shaft, and each form a tooth, or they may coalesce so as to form one tooth, so that we get four or five teeth, each directed its own way. The teeth or tooth-like structures which in the mentioned cases replace the alse, appear, as far as I have been able to observe, when the}- are quite separated from the shaft, to be upon the whole of the same construction as the genuine teeth, but this is only rarely the case, as most frequently they are only partly separated from the shaft. All these deformities, for as such they must be regarded, show the peculiarity that they are always symmetrical, occurring in quite the same way in both ends. Finally the ancorse are often somewhat twisted. 2. The small ancora; have a comparatively more curved shaft than the large ones, and further the teeth are less directed forward, so that a line through the two middle teeth would be straight or almost straight. In either end there are three leaf-shaped teeth, which are most narrow at the base, and an ala on either side of the shaft. Teeth and alse are comparatively long, so that the ends of the teeth approach each other, and the free middle part of the shaft is quite short, only ca. one eighth of the whole length, so that there is often only seen an incision between the alae. The length of these ancorse varies from 0-017 — o-o28mm, but the dimensions of the different parts remain about the same. The breadth is ca. 0-0057 — o-oo85mm. Also of this ancora a few developmental forms were seen. The two forms of ancorse are sharply separated, both by their sizes and by the characteristic form of the small ancora. A few ancora; may be found, however, that seem with regard to form and size to be intermediate between the two groups, yet with regard to form the}- approach always more nearly to the large ones. 3. Sigmata are more or less contort, up to one fourth of a turning. They are exceedingly varying in length, from 0024— o-075mm. The variation, however, is not so great in all individuals; thus the upper limit was measured in some specimens to o-o64mm, and in others to only I "!, the lower limit, on the other hand, seems to be about the same. The thickness varies alto- gether from o-ooi — o-oo5mm, according to the size. The middle sizes of the sigmata occur very sparingly, and therefore the impression is frequently imparted that sigmata form two groups; this fact is espe- cially conspicuous in the individuals in which sigmata reach the largest size, while the difference is smaller in individuals in which sigmata do not reach any considerable size. When they are divided in two groups, the fact is that the small sigmata may only vary a little in size, while the large ones PORIFERA II , ,- vary somewhat more. All forms of microsclera occur throughout the sponge; they are also found in the skin, and especially in large numbers in the membranes of tin- canals. Embryos. In most individuals embryos were found; they were present in large numbers and were lying rather close in the tissue. The embryos are globular, and their average size is 0*3 Of spicules only megasclera were found in almost all the examined specimens. These megasclera finely knotty, straight tylostyli; in the fine ones the head is most frequently found a little below the end, while in the thicker ones the end itself is swollen. Their length was measured from 0045 UP l" 0-i3mm by a thickness of o-ooi— 0-005""". Thus these needles are skeletal spicules, which accordil are the earliest occurring ones, whereas no dermal spicules were found, In a few embryos, in which the styli were of the largest sizes, also microscleres were found, that is to sa\ developmental forms of the ancorse; these forms were measured to a greatest length of o-028mm, but their form indicated that the}' belonged to the large form. Spicules were already present in all the examined embryos. Locality: We have a rather copious material of the species. Station 31, 66 35' Lat N., 55 54' Long. W., depth 88 fathoms; station 34, 65 17' Lat. X., 54'- r-7'Long.W., depth 55 fathoms; station 127, 66° 33' Lat. N., 20° 05' Long. W., depth 44 fathoms; Holstensborg (Bergendal); Egedesminde (Traustedt); Jakobshavn (assistant Olsen); Jan Mayen, depth 55 fathoms (the Amdrup Expedition 19001; the Bay of Skagestrand, depth ^ fathoms (Ditlevsen); east of Xolso, depth ca. 30 fathoms, at the northern end of Xolso, depth ca. 100 fathoms (Th. Mortensen). The localities are situated off West-Greenland, north of Iceland, off Jan Mayen, and off the Faroe Islands. Geogr. distr. The species is hitherto known from the coast of Jan Mayen (Marenzeller) ; from the Orkneys, the .Shetland Islands, the Hebrides, and the coasts of Great Britain and Ireland (Bower- bank); the Sound (Levinsen); the coasts of France, at the Channel and at the Atlantic, for instance the Bay of Biscay, at depths of ca. 96, 133, and 206 fathoms (the Caudan , Topsent), and finally from the Gulf of vSt. Lawrence (Lambe). In the seas in question it is thus distributed from 71 to 15 I. at. X. It is chiefly a shallow water- and shore-species, and the greatest depth, from which it is known, I supp to be stations 19 and 32 of the Caudan in the Bay of Biscay with a depth of ca. 2o(> fathoms (400 metres). Remarks: I have been able to determine this species with certainty, as I have examined a specimen sent by the Rev. Mr. Norman; this specimen showed distinctly the spined ends of the tornota. As will have been seen from the description, the species ina\ be somewhat varying, especially with regard to the size of the spicules, and it seems even to be able to vary still more than shown by m\ material; thus Lambe I.e. gives the lower limit of the styli to o-i2m" .\w\ of the tornota to ,»-: but here, perhaps, developmental forms are included. The species has sureh often been described under different names. As mentioned by Levinsen I.e., it is thus this species (X Schmidt has determined as fimbriata How., and, in Spong. des atlant Gebiet, I.e., quoted from Denmark and Greenla which fact is show n by the specimens in the museum at Copenhagen. I suppose that it ma\ also be regarded as a certain fact that M. barentsi Vosm. 1. c is identical with tin present species, and this seems also to hold good with regard to the .1/. barentsi mentioned 1>\ Lambe (Trans, of the R Soc. of Canada, [894, XII, Sect. IV, [21, PI. II, figs. 9, 9 a c). 1 also think that Has tat us Rob< I stdt., I.e., is the same species. With regard to both species the descriptions agree exactly with incrustatis. ( >i the two varieties of incrustatis, typica and viscosa, mentioned 1>\ Topsent (Arch, de zool. ex p. et gen. Tin- [ngoll I npi dition VI. 2 lS , ,g PORIFERA. II. Ser. 2, V, bis, suppl. ci8), on the other hand, at all events only the former is incrustans; the tornote figured by Topsent has smooth ends, but perhaps the spines, which may be very fine, have been over- looked; the tornote with cleft ends figured for var. viscosa, on the contrary, belongs, no doubt, to the following species. Finally Topsent (Resultats du Voyage du S. Y. Belgica, 17) describes a Dendoryx incrustans var. australis; 011 account of the sizes of the megascleres, the styli are 0-5— cr6mm, and the tornotes o'32mm, I think it more probable that it is an independent species. - The Halichondria incru- stans var. with angulated anchorate and smooth acuate* from the west coast of Florida mentioned by Carter (Proceed, of the Acad, of nat. Sc. of Philadelphia 1884, 205) cannot be the present species, but must belong somewhere else. 2. M. rosacea Lieberk. PI. IV, Fig. 8. PI. XIV, Fig. 4 a— h. 1859. Halichondria rosacea Lieberkiihn, Arch, fur Anat. 521, Tab. XI, Fig. 2. 1 so j. Myxilla rosacea O. Schmidt, Spong. des adriat. Meer. 71. 1864. Myxilla tridens O.Schmidt, ibid., Suppl. I, 36, Tab. IV, Fig. 5 a— d. 1864. Myxilla Esperii O. Schmidt, ibid., 36, foot-note. Myxilla rosacea Vosmaer, Notes from the L,eyden Mus. II, 123, 1. [882. Graeffe, Uebers. d. Seethierf. des. Golf, von Triest, Arbeiten aus dem zool. Inst. Wien IV, 6. 1888. Dendoryx incrustans var. viscosa Topsent, Arch, de Zool. exp. et gen. Ser. 2, V, bis, suppl. 119, PI. VI, fig. 16, b. 1890. Dendoryx incrustans var. viscosa Topsent, Mem. de la Soc. zool. de Fr. 201. 1892. - Topsent, Resultats des Campagn. scient. du Prince de Monaco, Fasc. II, 98. Tncrusting (sometimes forming free branches). The surface grooved, slightly shaggy. The dermal membrane thin, supported by penicillate bundles of dermal spicules. 'The skeleton a polyspicular reticu- lation, forming partly triangular meshes, partly quadrangular, or irregular ones. Spicule/: megasclera: the skeletal spicules acanthostyli, dispersedly spined 0-178 — \ the dermal skeleton; they are especially close-lying over the larger subdermal cavities, where they most frequently reduce the mem- brane to a network. They are round or oval, and their size is o-oi8 — o-nmm. Distinct ost ula were not seen. The skeleton. The dermal skeletal/ consists, as in the preceding species, of bundles of tornota which project from the main skeleton, being spread in a penicillate way, and support and pierce the dermal membrane. The bundles have generally a length of only about one spicule; only where large subdermal cavities are found, short fibres are formed of the tornota, which fibres pass into the mem- brane stretched over the cavity, and branch, continually sending fan-shaped bundles up through the membrane. The bundles are most frequently rather erect, but may in places he more or less recumbent Besides in the dermal skeleton tornota are also found in the membranes of, at all events, the larger canals. The main skeleton is a rather irregular, polyspicular network. It forms partly tetrahedral, partly more or less cubic or quite irregular meshes. Some longer fibres are found, especially running towards the surface. In the mentioned free branches rather long fibres are formed running lengthways of the branches. The fibres or spicula-bundles may have up to ca. six spicules alongside. As in the preceding species spongin is found in the nodes of the skeleton, but it is only to be observed with difficulty, as it is only present in small amount, and is quite white and clear Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli, they are most frequently slightly and evenh curved throughout their length, only more rarely they are straight; the point is even and middle long, but may vary a little in length. The spines are much scattered and rather small; only at the upper end they are a little more close-set, and are also here a little larger; the point is smooth for a longer or shorter space. The length varies from 0-178 <> 1 • and the thickness from o-ooS— o-oiimm. Some developmental forms were found, they were of different thickness, the finest ones were measured to ca. o-oooy'1"", and had a length of about tn.|'"m. Forms of a thickness oi about O'ooi"™ were slightly knotty or almost smooth, whereas Eorms a little thicker were distinctly spined. The developmental forms show a little distinct head-swelling, which is more distinct, the finer the needle is. 2. The dermal spicules are tornota; they are straight or slightly curved in different ways and slightly fusiform. Their ends are peculiarly formed; the\ taper onlj a little, and then they are abruptly cut off, the edge of the end thus cut off curies some small points, most frequently, as far as was to be seen, to a number of three. Sometimes the outer pari of the tornote is quite slightly swollen. Most frequently their ends are not quite equal, one being a little thinner than the other. Their length varies from 0-178— o-22mm, and the thickness from 0 o8mm. Developmental Eorms were seen in small numbers; in conformity to the development the) show the greater difference between the two ends, the younger they are. b. Microsclcra are of two forms, tridentate isanc unguiferse and sigmata. 1. The ancorse haw an evenh curved shaft; al either end they have three PORIFERA. II. teeth, and on either side a narrow ala. The alse continue along the shaft, and in the middle they are connected by a quite narrow rim; thus there is no free middle part of the shaft, but only an incision in the rim running on either side. The ancorse are very varying in size, their length is between 0-0157 and 0-05'"'", and the breadth is proportionately 0-004— o-oi8mm. The larger ancorse are most predominant. Developmental forms in different stages were seen. 2. Sigmata are of the common form and contort in different degrees; their size is rather varying, the length from o-oi8 — o-o32mm, and the thickness from ca. coon— o"002mir. Both forms of microsclera occur through the whole sponge and in no small numbers in the dermal membrane. Remarks: Of this species I have for comparison had a fragment of one of Schmidt's type imens sent to me by Dr. Marktanner-Turneretscher, and so I have been able to identify my species with certainty. It is also quite in conformity to Lieberkiihn's description and figures I.e.; especially the figure of the acanthostyli is exceedingly characteristic. On the other hand neither I.ieberkuhn nor Schmidt mentions the pluripointed ends of the tornotes, but they must also be seen under very high magnifying powers to be made out distinctly. In Schmidt's type specimen the megasclera are a little smaller than in ray specimens; thus the styli have an average length of o-i6mm, and do not exceed o-iyS"1"1, and the average length of the tornotes is o-i5mm, and they do not exceed o-ijS""". Schmidt describes later, under the M. tridens established by him in 1864 I.e., the three- pointed tornotes very minutely, and compares very appropriately the form of their ends to the head of an Ascaris. In 1868 he (Die Spong. der Kiist. von Algier, 27) joins, and, no doubt, correctly, this species to .1/. rosacea. When Vosmaer 1. c. further refers Schmidt's M. fasciculata here, and says that this species is different from fasciculata Lieberk., I take this statement to be owing to a mistake. An original preparation here in our museum of fasciculata. labelled with Schmidt's own hand, shows that this is a quite different species, even a species with chelae arcuatse, and a specimen of M. fasci- culata Lieberk. sent by Prof. v. Marenzell er, is quite agreeing with it as to spiculation. — Top- sent maintains (.Mem. de la Soc. zool. de Fr. VII, 1894, 16, the foot-note) that M. rosacea and M.incru- itans are identical. This, as will have been seen, is not the case; but it will appear from the following how Topsent has arrived at this conclusion. The fact is that Topsent (Arch, de Zool. exp. et gen. Ser. 2, V his, suppl. 118), as before mentioned, under iucrustaus mentions two varieties of this species, typica and viscosa, and while only var. typica can be identical with iucrustaus, var. viscosa. according to Topsent' s description, proves to be identical with rosacea. Topsent's description leaves no doubt of the identity-; he points out the pluripointed (Topsent says two-pointed) ends of the tornotes, he mentions the red colour, and finally he says that var. viscosa differs from var. typica by the presence of cellules spheruleuses with large grains. Now the fact is that rosacea really has these cells in exceedingly large numbers, they are seen in enormous quantities in the tissue, especially in the mem- branes; they have a diameter of ca. o,oi4n"n, and are filled with few, large, somewhat refractive grains. The .)/. rosacea var. japonica enumerated by Ridley and Dendy (Challeng. Report, XX, 130, PI. XXVI, fig. 3, PI. XXVII, figs. 8,8 a— c, PL XL, VII, fig. 3) must, according to the description, be a different species, and this holds also good of the M. rosacea var. mentioned by Lambe (Trans, of the Roy. Soc. of Canada, X, sect. IV, 71, PI. II, fig. 6, PI. V, figs. 6, 6 a-f), which has higly spined styli 0-24 — o-28mm long and simply pointed tornota o-22mm long. PORIFERA. II. l/,1 Locality: The Faroe Islands, 6 miles north to west of Kalso, depth 60 fathoms, 2 mil. Borovig, depth 20—30 fathoms, at the north end of Nolso, depth ea. coo fathoms (Th. Mo- northwest of Stronid, depth bo fathoms (Ad. Jensen, the cruise of the Michael Sars 1 Geogr.distr. This species, which was originally only known from tin- .Mediterranean, seems to be rather widely spread. Triest (Lieberkiihn) ; the canals of Venice (Schmidt); Algeria (Schmidt); at the Azores, depth 69 fathoms, off the northern coast of Spain, depth 72 fathoms, 45 48' I. at. X.. 5 Long. W., depth 85 fathoms ( l'Hirondelle , Topsent); at the French coast in the Channel at Luc and Roscoff (Topsent). The species is thus at present known from the Azores to the Faroe Islands. Its bathymetrical range is from ca. 5 fathoms (in the Channel) to ea. too fathoms (at the Faroe Island 3. M. fimbriata Bow. PI. IV, Figs. 9 to. PI. XIV, Fig. 5 a— i. 1S64. hodictya fimbriata Bowerbank, Mon. of Brit. Spong. II, 337, 43. 1874. Bowerbank, ibid. Ill, 147, PL LVIII, figs. 7— 14. t88o. Amphilectus fimbriatus Vosmaer, Notes from the Leyden Mns. II, ti6, 20. Cushion-shaped or formed as a round lump, sometimes slightly lobed. The surfact even, very slightly shaggy. The dermal membrane solid, supported by pcnicillate bundles of dermal spicules. Oscala scattered on the surface. The skeleton a polyspicular, most frequently irregular nehvork of triangular or quadrangular meshes. Spicula: Megasclera : the skeletal spicules acanthostyli , rather densely spincd, • •■j<> — o'4J'"m, the dermal spicules tornota 0'2j — o'j2"""; microsclera two forms oj aucorcc spatulu large ones 0-064 — o'Ot/""" . smalt ones 0-022 — o-ojj""". This species has a more or less lumpy, sometimes somewhat lobed form. It may be attached to different things; when growing on a rather extended substratum, as shells, it has often a flat, cushion-like form, but when it grows on worm-tubes, Hydroids, Bryozoa or the like, it becomes more roundish and lumpy. The smaller specimens seem to be the more regular ones, while the larger ones most frequently show the lobed or more irregular form. The specimens figured by Bowerbank I.e., which are all small, are thus rather regularly roundish, and he describes also the form as nearly globular, or more or less roundish . The largest specimens mentioned by Bow( 1 the size of a walnut, whereas I have before me considerably larger specimens; the largest one, which is of an irregular, longish form, has a greatest extent of about 8om,n, and then we have a series oi spei mens in evenly decreasing sizes, the smallest one has a greatest extent oi [2mm. The colour (in spiriti is most frequently more or less dark-brown, to almost black, a few specimens are oi a lighter tawny colour. I suppose that the fresh sponge after its death becomes dark by the influence "i the lighl in spirit, as the dark specimens, when cut through, are seen to be lighter inside, and the light colour begins just under the surface-. As slated by Bowerbank, the sponge also becomes dark when di The consistenc) is somewhat elastic, and the sponge may be rather hard and firm, or softei and loo The surface is even and apparent!) smooth, but undei the magnifying glass it is seen to be slightly shaggy from projecting spicules. The dermal membram is a rathei and not especially thin film, which may very easily be isolated; it is supported by projecting bundles of dermal spicules spread in a penicillate way. These bundles are most frequently ver\ close-set; thev mav be erect or more or less l., PORIFERA. II. recumbent; when bending over large subdermal cavities they are always recumbent. Sometimes the dermal spicules arc quite recumbent and scattered in the membrane, and then it rests on the main skeleton, from which spicules may project through it. The pores are partly lying singly, scattered among the projecting spicula-bundles, partly they are closely gathered over the subdermal cavities where the) form sieves. Their size was measured from o-oi8 — o-i2m,n. Oscula may occur in very varying numbers; most frequently they are rather few and scattered, but in a few cases they are numerous, and may then in places be close-standing. Bowerbank says: < Oscula simple, dispersed, numerous . They are round, with a sharp, sometimes a little raised edge. Their size was measured from 0-5— 4""". The skeleton. The dermal skeleton, as mentioned above, is formed of close-set penicillate, more or less erect bundles of dermal spicules. They may sometimes be quite horizontal and scattered in the membrane. The main skeleton consists of polyspicular fibres with up to six spicules alongside; it forms a rather irregular network of triangular and quadrangular meshes. Some longer fibres are found running towards the surface, and they may be connected by transverse bundles, so as to form more regular, quadrangular meshes; these fibres may in places be rather numerous. A rather slight amount of spongin is found in the nodes of the skeleton. Spicula: a. Megasclera. 1. The skeletal spicules are straight or slightly curved acauthostyli ; the curve is most frequently nearest to the rounded end. The point may be somewhat varying, from rather short to middle long or rather long, in the latter case it is bounded by straight lines; in a few cases the point is rounded. The spiimlation is rather dense, but the spines are small; thev are often somewhat scattered in dots; most frequently the spines are a little closer gathered and also a little larger at the head-end and near the point, while they are smaller in the middle. Bowerbank designs this feature as < incipiently spined .. The spinulation ma}- be more or less marked, and when it is slight, the spicule may be almost smooth in the middle. The point is most frequently without spines, but sometimes they continue to the very end. The length varies from ca. 0-26— o-43mm, and the thick- ness from ca. croi— o-024muJ. The small sizes are not frequently found. As well with regard to length as to thickness a little difference may be found in different individuals. Developmental forms of different sizes were found in small numbers; the young ones have a slight head-swelling and a rather closely, but finely spined or knotty- surface. 2. The dermal spicules are tornota; they are straight, only sometimes a little sinuous. The points are short and bounded by curved lines, but end with a little mucro. The tornotes are sometimes quite slightly constricted inside the points. The two ends are almost never quite equal, but one is a little thinner and a little longer pointed than the other. Tluir length is between 0-23 and o^a"11", and the thickness in the middle is 0-005 — o-oi2mm. Develop- mental forms, of which the young ones are styli, occurred, but in no great numbers. — In this species it is almost always distinctly to be seen, which end of the tornotes is the original point, as it is always thinner and longer pointed, while the other end is broader pointed and has most frequently a more distinct constriction below the point (P1.XIV, fig. 5 e). These spicules also generally grow rather thick, while one end still continues to appear as a distinct apex; this fact is, I suppose, what leads verbank to speak of acuate tension spicula»; otherwise he is somewhat obscure, and in his diag- nosis he calls the spicules of the dermal membrane tacerate , but further says: «Interstitial membranes. PORIFERA. II. 1a? Tension spicula acuate , whereas, in the description and in the third volume under the explanation of the figures, he speaks of the spicules of the dermal membrane as monactinal oiks. b. Mien these are tridentate isancorse spatuliferse of two sizes, i. The large ancorae have a somewhat curved shaft, the teeth are oval and more or less broadly rounded at the end, sometimes pointed. The shaft has distinct alse, a trifle longer than the teeth. The free part of the shaft between the alae is about one fifth of the length. The ancora may vary somewhat in form, be more slender or more robust, and the tooth may vary a little in breadth. The length varies from (V064— ! the two ends approach considerably in the middle. Their length varies from o-022 -O/035111"1, and the thickness of the shaft is 0-0021— O'ooaS. Developmental forms in different stages are found of both forms of ancorse, from exceedingly fine ones with only slight traces of teeth. Transitional forms between the two forms of ancoraj have not been observed in this species. Both forms occur in the dermal membrane and in the membrane-like parts of the sponge, often in large numbers; the small ancora is the more frequent one. Embryos. In some of the individuals embryos were found copiously in the tissue. Thev are globular, the largest ones of a diameter of ca. o-T,mm. The smaller ones had no spicules, then mega- sclera occurred, and the larger ones showed both megasclera and developmental tonus of the small ancora. The megasclera are spined tylostyli reaching a length of up to o'i4""" and a thickness below the head of up to croo4mm. The developmental forms of the ancora were of the same length as in the grown sponge. At first the megasclera occur in small numbers and scattered; later, at the same time as they grow larger, they are numerous and closely gathered in a bundle; they are, especialh at the head-end, far more coarsely spined than in the developed sponge. In the largest embryos the small ancora was fully or almost fully developed. The specimens in question were obtained in the months of May and July. By comparison with a specimen of J/, fimbriata Bow. sent me by the Rev. Mr. X or man I have been able to identify the species with certainty. From incrtisians it is separated, beside- b\ other characters, by the absence of sigmata; otherwise it is well characterized by its round or round-lobed form, its even surface, and the solid, not thin dermal membrane. Locality: The species has been taken by the Ingolf, station 32, 66 35' Lat N., 56 38' Long. W. depth 318 fathoms; station 85, 63 " 21' Lat. X., 25 n' Long. W., depth 170 fathoms; station So, 64 45' Lat. X., 27 20' Long. W., depth 310 fathoms; station 98, 65 38' I. at. X.. 26 .:;' Long. W., depth [38 fathoms; station 127, 66 33' Lat. X., 20 05' Long. W., depth 44 fathoms. It has further been taken at the following localities: Iceland, Cape North, depth ca. 37 fathoms (Ditlevsen); 64 27 Lat. N., 1.; Long. W., depth 84 fathoms, 60 53' Lat. X., 8 56' Long. W., depth 69 fathoms, 0.: 23' Lat. N., 2 35' Long.E., depth 217 fathoms (Ad. Jensen, the cruise of the Michael Sars 10021; the Faroe Islands, at the south end of Xolso, depth ca. Si 1 fathoms, at the north end of Nolso, depth ca. [OO fathoms, 9 miles east of Xolso, depth ca. 30 fathoms, 6 miles north to west of Kalso, depth horns, S miles south- east of Miaveiues, depth 40 fathoms, off the mouth of Borovig, depth ca. 30 fathoms (Th. Mortens* southwest oi Myggenaes, depth 13s fathoms (Ditlevsen). Alto-ether about twenty largei and smaller I++ PORIFERA. II. specimens. The localities are situated in the Davis Strait (station 32), in the Denmark Strait (stations 85, 89, and 98), north of Iceland, round the Faroe Islands and off the coast of Norway. The depths are from 30 318 fathoms. Geogr. dish: The species was hitherto only known from the Shetland Islands (Bowerbank|. 4. M. brunnea Arm. Hans. PI. IV, Fig. 11. PI. XIV, Fig. 6 a— h. 5. Myxilla brunnea Armauer Hansen, The Norwegian North-Atlantic Exp. XIII, Spongiadse, 12, PI. Ill, fig. id, PL VI, fig. 5. Erect, more or less irregularly leaf-shaped, sometimes lobed or in other ways irregular. The sur- face grooved or curly, not shaggy, or only imperceptibly so. The dermal membrane a rather thin film, supported by pen ni Hate tain dies of dermal spicules, and in some places with horizontal spicules. The skeleton a somewhat irregular, chiefly polyspicular network with quadrangular or irregular meshes: primary longitudinal fibres are found running up through the sponge and bending towards the surf, tee. Spieu/a: Megasclera: the skeletal spicules acauthosfyli and acauthosfrougyla 0'2j6' — 0'jSmm, the dermal spicules lornota with two- to four-pointed ends 0-20 — o-2g"""; microsclera two forms of ancora spatuliferce, large ones irojj—vc>6j""", smalt ones tru->/—crojj""". This species is erect, and is more or less, but often very indistinctly leaf-shaped. It is attached below ; the specimens that have not been torn off from the underlayer, are attached to shells, Balanae or stones. The most regular specimens are quite leaf-shaped, and are at the base narrowed to a quite short stalk. Of this -form we have one specimen, 95mm high, 65'""1 broad, and ca. 5mm thick. Then we have some specimens that are more irregular, the leaf being thicker and more irregularly lobed, and the form of a leaf may be quite effaced. These specimens, which appear to have been attached with a broad base, are 40— 75mm high and of similar breadths. A few smaller specimens are more ramiform. Finally we have a specimen attached to a stone, which from a lower lobed part passes above into two lobes forming together an open, bilobate calyx. The consistency is little elastic and rather brittle; the thin leaves are more flexible. For some of the specimens taken by the Ingolf, the colour of the fresh sponge is stated to have been dark orange; in spirit all the specimens have a dark brown to almost quite black colour; only very few ones are of a lighter shade. When cut through they show a lighter colour inside. The surface is highly grooved or curly; for, the sponge being traversed by a number of horizontal canals, the dermal membrane forms over their mouths sunk grooves, separated by curly or sinuous ridges. The surface is otherwise smooth, or finely, almost imperceptibly shaggy- from projecting dermal spicules. The derma/ membrane is a rather thin, but tolerably solid and easily separable film, partly supported by penicillate bundles of spicules, partly provided with scattered spicules. The pores are, as usual, King in the dermal membrane, sometimes scattered, sometimes very close-set; they are round or oval, but in places where they are close-lying often of an irregular form. They were measured to about 0-029— 023"lm. The question as to the oscula is not easily decided. A great number of canal-mouths are seen in the surface, but main- of these apertures have evidently their origin from the fact that the dermal membrane is damaged, either torn over the canals, or quite wanting, and it is impossible in each single case to decide, whether damaging has taken place. Where, however, the membrane is PORIFERA. II. Zac preserved to any greater extent, circular openings oi a diameter of about <>=,"':' arc found in k few smaller ones, ami these openings must he regarded as oscula. In the thicker, irregularly leaf- shaped specimens a lew wide perpendicular canals are also often found, opening in the edge; hut I am not quite sure, whether the question is here of real oscular canals, or the) are secondary canals arisen by coalescing. In the membrane coating these canals, dermal spicules are found and also pore- shaped openings; this, however, does not exclude the fact that the) ma\ belong to the original canal system, and, on the other hand, in undamaged specimens their mouths are surrounded by tin- dermal membrane as a round, sharply bounded opening. 1 therefore regard it as probable that the question is of oscula, and the fact is then that the small oscula on the surfaces lead to the smaller, horizontal canals, while the oscula found in the edge are larger and lead to longei perpendicular canals which pass down through the thicker parts of the irregularly leaf-shaped sponge. The skeleton. The dermal skeleton, as mentioned above, consists chiefly of bundles of dermal spicules, which are spread in a somewhat penicillate way and .support the dermal membrane, and, hut only to a slight degree, pierce it. This skeleton is otherwise little regidar, the bundles are most frequently more or less recumbent, often quite so, and scattered spicules may also be found in the membrane; in some places the skeleton may be formed entirely of horizontal, scattered spicules, which seems especially to be the case in places where no pores are found. The ridges of the surface are often seen to be more spined, which is then owing to the fact that the spicules of the skeleton itself lure project through the dermal membrane; I suppose, however, that this feature is often due to damaging. Tornotes are not found in the membranes of the canals, except in those of the above mentioned larger longitudinal canals. The )iiain skeleton is a somewhat irregular, mostly polyspicular network. The meshes are mainly quadrangular or rectangular, but may also he more irregular. The skeleton has otherwise a similar structure as in many leaf-shaped Renierse and Chalininae, longitudinal fibres being found running from the base up through the sponge, and bending to all sides towards the surface, accord- ingly as well towards the two sides as towards the edges. When the skeleton is most regular, these fibres are running parallelly with a distance between them of about one spicule; the conin msvers< spicules may be placed perpendicularly on the longitudinal fibres or more or less irregularly, and with greater or smaller distance between them, but long secondary fibres are not found. The longitudinal fibres may reach a thickness of up to o-i5mm, and have a considerable number of spicules alongside; the transverse fibres, on the other hand, are single spicules 01 bundles of only few spicules. Often the skeleton seems to be somewhat less regular. Spongin is distinctly present in the mules of the skeleton, but it is verv clear; also in the longitudinal fibres it is found rather copiously. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli and acanthostrongyla mixed in about equal numbers; they are straight or most frequently slightly curved with the curve nearest to the basal end. The spinulatiou may be somewhat varying, sometimes it is rather dense. sometimes more scattered, and almost quite smooth needles may be found singly. The spines most frequently rather coarse; at the upper end they are a little more close-set ami generalh some- what larger. The sty li have a sharp, middle long to rather Ion-, point, which is oftenest smooth through its whole extent. The strongyla are distinctly seen to be monactinal, being always broader at one end than at the other, so that a distinction is always found between a basal end and an ap The [ngoIf-Expedition. V I 146 ] 'OKI [■ERA. II. end corresponding to the point; they are otherwise of the same form as the styli, but are spined throughout their length, and the spines are generally more close-set, not only at the basal end, but also at the apical one. Although styli and strongyla are certainly nothing but modifications of the same form of spicule, which is also seen by the fact that the strongyla seem upon the whole to be a little shorter than the Styli, no transitional forms, or, at all events, only very few ones, are found between them. The length, which may be given collectively for styli and strongyla, varies from 0-238 — o-3>/ two terms, aueoru- sfatuh' ngmata o'oiS — u-ojp""1 . This species is of an irregularly lump)-, slightly lobate form; the two specimens in hand are attached to Hvdroids, one of them together with a small specimen of Halichondria panicea oi a similar form. One specimen has a greatest extent of 35""", the other of hardl) 20mm. The colour (in spirit) is a dirty gray. The consistency is slightly elastic. The snrfact has more or less deep, irregular grooves or folds, otherwise it is apparently smooth. The dermal membrane is a very thin film, partly suppi by somewhat projecting, but highly recumbent fibres and bundles of dermal spunks, partly in places provided with horizontal, scattered spicules. Pores are found in some places of the surface in dense groups, the) were measured to a diameter of up to 0,o6mm. Oscula were not found. The skeleton. The dermal skeleton consists in most places of bundles of tornotes, which sup the membrane, but are generally more or less recumbent, most frequently highlv so. In other places I |S PORIl'KRA. II. tilt- tornotes seem to be quite horizontal and often scattered in the membrane. The main skeleton of this species, as far as I have been able to decide from the slight material, is only little differentiated. It consists of a rather dense, but diffuse framework of spicula-bundles and spicules, and no real network, or, at all events, only a quite irregular one is formed. In the skeleton rather long and thick, but loose fibres occur, but they have also a quite irregular course; these fibres, in which many spicules are found alongside, reach a thickness of up to o-i2mm. Spongin, no doubt, is present, but only to a very slight degree. Spicula: a. Megasclera. i. The skeletal spicules are straight or slightly citrved acautho- styli with an even and rather long point; the spinulation is powerful, the length of the spines being generally more than half the diameter of the needle. Generally they are gathered closely at the head- end and continue over the tapering almost to the very point. Their length varies from 0-14 — o-2o8mm, and the thickness from 0-004 — o-oo7mm. Quite few fine developmental forms were seen. 2. The dermal spicules are tornota; they are straight or a little irregularly curved; they are otherwise of a similar form as in incrustans, but the ends are sharper and more lanceolately pointed; a slight narrowing is almost always found below the end. The points are exceedingly slightly and finely spined, sometimes smooth. In the fully developed tornotes the ends are equal or about equal. Their length is 0-13 — — o-i78mm, and the thickness varies from ca. 0-0035 — o-oo5mm. b. Microsclera ; these are of two forms, three-toothed isancorse spatulifene and sigmata. 1. The ancorse are of the same type and of a similar form as the small aneorae of the preceding species; they have an evenly curved shaft, and three leaf-shaped teeth and a narrow ala at either end. Their length varies from 0-018 — o-030mm, and the thickness of the shaft is 0-0014— o-oo2mm. 2. Sigmata are small, of the common form, and more or less contort; they are characteristic by their highly recurved ends. Their length is 0-018 — o-024mm, and the thickness is 0-0007— oooi4mm. The ancorse are especially found in the dermal membrane, btit they are otherwise only present in small numbers, sigmata occur far more frequently. Locality: Faskrudsfjord in Iceland, depth between 20 and 50 fathoms (Horring), one specimen; Jan Mayen, depth 50 — 60 fathoms (The Amdrup-Expedition), one specimen. 6. M. pedunculata 11. sp. PI. V, Fig. 2. PI. XV, Fig. 1 a— d. Club-shaped, stalked. The surface slightly shaggy. The dermal membrane thin, supported by bundles oj dermal spicules, and in places with horizontal spicules. The skeleton consists of polyspicular primary longitudinal fibres connected by irregular transverse spicula-bundles and spicules. Spicula: Megasclera: the skeletal spicules smooth sfyli t>-j6 — o-^o""". the dermal spicules tornota 0-238 — o-jy""",- microsclera of one form, ancoro?. spatuliferm 0-054— o-o66mm. This species is of a somewhat club-shaped form; below it has a rather short stalk attached by a small basal expansion ; above it passes into a thicker part which in the best preserved specimen is somewhat triangular and slightly compressed. This specimen has a height of 22mm, and a thickness above of iomm, the stalk is about 5mm long and imm thick. The smallest specimen is about io,nm high; it is more evenly club-shaped without any marked stalk. Of the specimens one is attached to a stone, PORIFERA. II. ^o the two others to living specimens of an ^4raz-species. The colour (in spirit) is light brownish. The consistency is rather soft, but somewhat elastic. The surface, as tar as I have been able to observe, is slightly shaggy when undamaged; in many places in the specimens in hand it is more shaggy, the ends of primary fibres projecting, but this, I think, is only due to damaging. The dermal vicmbrane is a thin film, mostly supported by bundles of dermal spicules. Pores and oscula were not observed. The skeleton. The dermal skeleton, as far as I have been able to see, consists of bundles or short fibres ot dermal spicules, issuing from the skeleton and supporting the dermal membrane; this membrane, however, has also in places horizontal, scattered spicules, and, besides, it is highly filled with microscleres. The primary fibres of the skeleton pass perhaps also in places quite to the surface. The man/ skeleton consists of primary longitudinal fibres, passing from the stalk up through the sponge, branching and bending to all sides towards the surface. These fibres are polyspicular and powerful, and in the lower part of the sponge, above the stalk, they may be o-25mra thick; upward and outward they become thinner. Regular secondary fibres are not formed, but between the longitudinal films are found partly transverse spicula-bundles, partly single transverse spicules, placed more or less irregularly. A distinct, but clear and little conspicuous mass of spongin is found. It is especially visible in the nodes, but it may also often be seen to coat the longitudinal fibres witli a very thin layer. Down in the stalk the spongin is more copious and of a yellowish colour. Spicula: a. Megasclera. i. The skeletal spicules are smooth styli; they are somewhat curved, most frequently nearest to the head-end, more rarely they are straight. They tape] evenlj to an about middle long point. Their length varies from 036 — o^o"'"', and the thickness is in proportion 0-014 — 0'02iml". Quite few finer developmental forms were seen. 2. The dermal spicules are tornota; they are cylindric and straight, or more rarely quite slightly curved. In the form of their ends they are most similar to the tornota in J/, fimbriata, the ends being rather stubby, but with a little mucro at the apex. Generally one end is a little thicker than the other. Their length is 0*238 -0-34'™, and the thickness is 0-007 — o-oo8mm. Developmental forms with one end quite pointed were found quite singly, b. Microsclera; these are of only one form, three-toothed isancorse spatulifi These ancorte are of a similar form as the large ancorse in the preceding species; the teeth are most frequently broadlv rounded at the end, and narrow ake are found of the same length as the teeth. The length of the ancorte is between 0-054 and or>66""", and the thickness of the shaft is ca. 0005 niki-""". The ancorae occur throughout the tissue, but are cspecialh numerous in the dermal membrane. Embryos. In one specimen embryos were found; the} were scattered in the tissue and were easily distinguished by their dark, yellowish red colour. They are globular, of an average diameter of o-26mm. Most of the specimens examined showed no spicules, 01 only a few small styli which would thus seem to be first appearing. One of the embryos, on the other hand, had both megascleres and microscleres. The megascleres are small subtylostvli, they are not smooth, but spined or rugged. The microscleres were developmental forms of the ancora, they were smaller than in the developed sponge, only ca. 0-035""" l°n& The specimen in question was obtained towards the close of July. Locality: Station 2, 63 04' Lat. N., S 21' Long. W., depth 262 fathoms, one fragment; station , 05'Lat.N., 8 26' Long. W., depth 371 fathoms (bottom temperature : o lC), two specimens. 01 the localities one is situated south of Jan Maxell, the other between Iceland and the Faroe Islands. Xc0 PORIFERA. II. I suppose that the species must be regarded as a native of the cold bottom; station 2, to be sure, shows a temperature of 5°3 C, but this station is situated on the Iceland-Faroe ridge, and here, I think, the circumstances may be changing. Note. Topsent, in 1904 (Resultats des CamjDagn. sc. du Prince de Monaco, Fasc. XXY, 174, PI. Ill, fig. 5, PI. XIV, fig. 17, PI. XVIII, fig- 2), has established a genus, Sfelodoryx with the species procera; this species has an exterior and a skeletal structure quite similar to that of pedunculate/, its microsclera are ancorse with five teeth at either end. Topsent says that it is related to Lissodcu- doryx by its smooth skeletal spicules, but deviates by its skeletal structure, which latter fact is his principal character for the establishing of the genus. On this character, however, the genus surely cannot be maintained, and as the species has ancorse, it belongs to Myxilla. It seems, by its five- toothed ancone, to be closely allied to the following two species, diver siancorata and plurideufata. of which diver siancorata seems to be closely allied to it also by its form and skeletal structure. 7. M. diversiancorata 11. sp. PI. Y, Fig. 3. PI. XV, Fig. 2 a— i. {Erect, stalked?). The sue/ace slightly shaggy. The dermal membrane thin, supported by bundles qf dermal spicules. The skeleton an irregular reticulation of polyspicular longitudinal fibres connected by scattered spicules and spicuta-bui/dtes. Spicu/a: Megasclera: the skeletal spicules smooth styli 0'j8 — o-6 J""", the dermal spicules toruota o-j2? — ir^j.S'""",- microsclera two porius of plurideutate ancorw spa- tulifcrte. targe ones with five, sometimes six to seven teeth troyi — o'Opg""". small ones with seven to eight teeth ceojj/ — 0-048""". Of this species we have only a very scanty material, viz. two specimens, both more or less damaged. The largest specimen has a somewhat irregular ovate form, and looks as having belonged to an erect sponge. It is broken below, and perhaps it has had a stalk. It has a height of i7mm and a greatest breadth of nra,n. The other specimen is a very small one, attached to the shell of a Brachiopod, and it is assuredly only a fragment. The colour (in spirit) is light brown. The consistency is rather soft and somewhat elastic. The surface, where it is undamaged, seems to be slightlv shagrsrv. The dermal membrane is a thin film, which, as far as I have been able to see, is supported by more or less projecting bundles of dermal spicules. It is filled with microscleres to an exceedingly high degree. Pores and osci/la were not seen. The skeleton. The dermal skeleton, as before mentioned, seems to consist of spicula-bundles issuing from the skeleton and supporting the dermal membrane. The main skeleton consists of a rather irregular reticulation of polyspicular, but rather loose fibres. Longitudinal fibres occur, especially running up through the sponge and sending branches to the surface or bending out to the surface, but their course does not seem to be regular, as it is, for instance, in the preceding species. Transverse fibres are not formed, but bundles of spicules or single spicules are irregularly scattered between the longitudinal fibres. Spongin is found in the fibres, but being little copious and exceedingly white and clear it is only to be observed with difficulty; it is most distinctly seen in the nodes. Spicula: a. Megasclera. 1. The skeletal spicules are smooth styli, somewhat curved, almost PORIFERA. II. J5I always nearest to the rounded end; the point may be somewhat varying, but is upon the whole middle long or rather long; sometimes it is abruptly more shortly pointed at the very point itself. Their length is 0-38— o-62'n'", and the thickness is proportionate^ 0012 — o-02imra The smaller sizes are little frequent. Developmental forms occurred in small numbers, the finer ones were slightly rugged. 2. The dermal spicules are tornota; they are cylindric and straight, or slightly, not rarely some- what irregularly, curved; the ends are shortly and bluntly pointed with a little outer point marked off especially. One end is always a little thicker than the other, and this latter is generally a little longei pointed. Their length varies from 0*327 o-ps^""", and the thickness is ca. o-oo6 — o-oimn\ Very few finer forms occurred, the thin ends of which were quite pointed, and accordingly they were styli. b. Micro- sclera; these are two forms of pluridentate isancorse spatuliferse, larger and smaller ones. 1. The large ancorse are of a very beautiful form; the shaft is slightly curved, and they have at either end five lanceolate teeth and a pair of narrow alse of about the same length as the teeth. The teeth are placed in such a way, that a transverse section of the ancora through the teeth is about circular. Ancorse with six or seven teeth, or with six or seven teeth at one end and five at the othei end occur singly. Not rarely the ancorse are a little twisted, so that the teeth oi one end are situated opposite to tlie intervals at the other end. Their length is en >; 1 - < >< >uc/"m, and the thickness of the shaft is 0*0057 — o'oo8onim. Developmental forms of this ancora at all stages occurred frequently. The youngest ones are quite fine, and look as if they had at either end a single, median, hook-like recurv- ing, so that it might be supposed that the median tooth was the one first formed. By a closer exa- mination, however, a couple of ridges are seen at the end of the shaft, which are surely beginning teeth, but on account of the smallness and fineness of the parts it is a very difficult thing to get a clear view of the exact structure of the end of the finest stages; soon after, in stages a little older, all five teeth are seen as thin, plate-shaped outgrowths, so that it may more nearly be said that falxes are first formed. 2. The small ancorse are also of a highly beautiful form; they have an almost straight shaft, and seven to eight teeth and narrow alse at either end. The alse most frequentl) con- tinue along the middle of the shaft as a narrow rim. The teeth are about parallel to each othei and to the shaft, and they are very close-standing; they are so long as to be onlj little removed from each other in the middle. Most frequently the teeth are slightly curved, so that the ends are directed a little inward. The length is 0-0357— o-OdS""", and the thickness of the shaft is 0*0028 0-OO35mm. The large ancora occurs numerously, and in especially large numbers in the dermal membrane; the small ancora, on the other hand, is far less abundantly present. Embryos. Some embryos were found scattered in the tissue; they are globular and <>l a si ( oi up to u'3""". In the specimens examined no spicules were found. Locality: Station 85, (13 21' I. at. X., 25 21' Long. W., depth 170 fathoms; station So, 64 |V hat. X., 270 20' Long. W., depth 310 fathoms. Both stations are situated in the Denmark Strait. 8. M. pluridentata n. sp. PI. V, Fig. 4. PI. XV, Fig. 3 a 1 Cushion-shaped. Tht surface slightly shaggy. The dermal membrane thin, until pcnicillate Inn 1 dermal spicules. The skeleton an irregular, polyspicular reticulation. Spicula: Mcgasclcra. letal tc2 PORIFERA. II. spicules smooth styli o-j2—o-jo""". the dermal spicules strongyla or subtylota, most frequently with slight spines at the ends, u-2j6 — ojj""": microsclera oj one form, ancorce spatuliferce with five to seven teeth croji — crog/""". ( )f this species we have no great material either, only three specimens; two of them are entire oiks ; they are cushion-shaped and are attached with a broad base. One of these specimens, however, is torn off, the other is attached to a calcareous alga. One specimen has an extent of 20m"', and a thickness of 9mm, the other is a trifle smaller. The third specimen is the largest one; it is a much damaged fragment and consists chiefly of the part that has been nearest the nnderlayer; it has an extent of 25""11, its form would also indicate that the whole sponge has been enshion-shaped. Also this specimen is torn off from the nnderlayer, but both the torn off specimens show on their basal surfaces pebbles and remnants of Bryozoa. The colour (in spirit) is brown. The consistency is rather firm. The surface seems in undamaged places to be slightly shaggy. The dermal membrane is a very thin film. Pores are found in the membrane, in places very close; the}' vary in size from quite fine apertures to a diameter of ca. o-2iram. Oseula were not seen. The skeleton. The dermal skeleton, as far as I have been able to decide from the slight material, consists of bundles of dermal spicules spread in a more or less penicillate way; they project from the skeleton below and are erect or more or less recumbent, and spicules are also seen in small numbers King horizontally in the membrane. In places the dermal skeleton seems to be less developed, and here the fibres of the main skeleton seem to project, but this feature is perhaps due to damaging or contraction. The main skeleton is a rather dense, but irregular reticulation of polyspicular fibres. Most markedly occur fibres that have a tolerablv distinct course towards the surface, and these fibres are the thickest ones with many spicules alongside, but they have no regular course. Between them short fibres and spicula bundles are found placed quite irregularly, so that a network is formed, irregular in most places, and in it, moreover, many single spicules are found. A distinct mass of spongin is found in the fibres, and in the nodes it becomes rather copious. Spicula: a. Megasclera. 1. The skeletal spicules are smooth styli somewhat curved, most frequently nearest to the head-end; sometimes they are a little irregularly curved. The point is rather short, at most middle long; it may, otherwise, be somewhat varying, sometimes the style tapers evenly and the outermost point is short, sometimes, on the other hand, the point may be of a rather consider- able length, and in both cases it may be bounded bv straight lines; in other cases the shorter or longer point may be distinctly marked off. The length of the styli is 032 — o-5omn', and the thickness is ca. 0009 "mio™"\ Length and thickness are often in no absolute proportion to each other, long, but rather thin styli being especially often seen. Developmental forms occur in small numbers, they are not rugged. 2. The dermal spicules vary between strongyla and subtylota. They are eyliudrie and straight or slightly curved. The form of the ends is somewhat varying; sometimes they are simply rounded or bluntly pointed and not swollen or oulv slightly so; they may be smooth, but they have most frequently a lew line .spines. Frequently, however, they are somewhat swollen, from almost imperceptibly to very distinctly so, and with broadly rounded or almost cut off ends, where they have more or less distinct spines; frequently the swelling is also slightly ribbed. Generally one end is PORIFERA. II. !-, distinctly thicker than the other, and the finer they are. the more conspicuous is this feature. .Mon- strous forms with several swellings are not unfrequently found. Their length varies from 0-226— 0-32""", and the thickness from 0-005— p-oionn". b. Microsclera ; these are of one form, plurideutate isancorse spatuliferse; they remind of the aneora: of the preceding species, hut are" more slender; the shai somewhat curved, either evenly, or, what is frequently the case, with a somewhat sharper bend in the middle. At either end is found a number of teeth which seems most frequently to be five, but may also be six or seven, and the number may be different at each end; otherwise some irregularity is found in the construction, the teeth may be of different length, often in such a way, that the lateral teeth are the longest, but also often in a quite irregular way. A narrow ala is found at each end, also often showing some irregularity; it continues generally as a quite narrow rim along the middle of the shaft. The length of the aucora; varies from 0-071 — 0-097""", and the thickness of the shaft is 0-0042 — o-oo57mm. The aneora: are found throughout the sponge, but are not especially seen in the dermal membrane. Locality: The Ingolf, station 127, north of Iceland, 66" 33' Lat. N., 20°05' Long. W., depth 44 fathoms; the Bay of Skagestrand in Iceland, depth ^ fathoms (Ditlevsen); Axarfjord, depth 20 fathoms (H. M. S. Beskytteren Otterstrom). Three specimens in all. Note. The present species and the preceding one are closely allied to each other, and at first I was inclined to regard them as one species; it is, however, chiefly the occurrence of the peculiar pluri- dentate ancorse, by which thev become so closely allied, while other characters, which are quite constant in the material in hand, separate them from each other. These characters are especially the occurrence of the two different aneora; in one species, while in the other only one form occurs, the marked difference in the form of the dermal spicules, and the difference in the skeletal structure. Of Myxilla-species with pluridentate ancoroe two have hitherto been described, viz. the Stelo- doryx procera Tops, with five-toothed aneora;1) mentioned before under pedunculata, and the Dendoryx dentata described in the same place (172, PI. XIV, fig. 19) with ancone with five to six teeth at either end ; both species are jlfy.rtl/a-species. Of the Dendoryx pectinata with peculiar ten-toothed ancorae established by Topsent in [892, on the other hand, I dare say nothing with certainty; the species might perhaps be an lotrochota- species without birotuke. Lissodendoryx Tops, (emend.). The exterior passes through all forms, /nan incrustations through massive, often /nor, lobed tonus, to croc/, club-shaped, or finally digitate or richly branched forms. The skeleton is somewhat dependent on the form: if may lie a diffuse and quite irregular polysplenia)- reticulation, in the ma forms longer fibres may be found, in the branched forms distinct primary longitudinal fibres may occur, and it may finally be of dendritic typo. Spongin is present more or less copiously. Spicula: Mcgaschra: the skeletal spicules are smooth or spined slyll. the dermal spicules are diactinal, torn ta, strong Tl Perhaps two species may be hidden under this one, Topsent mentiouir itnen with considers megascleres and with ancorae with five t" six teeth. The Ingolt-E icped \ I 20 ie. PORIFERA. II. or similar forms, sometimes with spined ends; microsclera arc chela- arciiatir of one or more forms, and often sigmata. The genus Lissodendoryx was established by Topsent, first in 1892 (Resultats des campagn. scientdu Prince de Monaco, Fasc. II, 97), as a subgenus of Dendoryx t= Myxilla), and later, in 1S94 (Mem.de la Soc. zool. de Fr. VII, 35) raised to an independent genus. The typical species was L. lepto- dcrmu Tops. The species first described among those belonging to Lissodendoryx seems, as stated by Topsent, to be L. isodictyalis Cart, described by the author under Halichondria. Later, Topsent (Rev. Suisse de Zool. IV, 1897, 457) has described a species from Amboina, which he identifies with isodictyalis Cart., and at the same time he identifies his own leptoderma with this species; according to this, isodictyalis Cart, would become the type. Thiele (Studien iiber pazif. Spong., Zoologica, Heft 24. 11, 1899, 18, Taf. V, Fig. 10) thinks, however, that Topsent's species from Amboina is not identical with isodictyalis Cart., and gives it the name of simi/is; at the same time he says that he cannot decide with which of the two species leptoderma may possibly be identical. Accordingly leptoderma must still for the present be regarded as the type of the genus. The character by which Topsent distinguished the genus from his Dendoryx, was exclusively the smooth styli in contradistinction to the spined ones in Dendoryx. This character is a very unten- able one, as species are found with scarcely perceptible spinulation, and Topsent himself admits also this fact. Instances of such species are Jirma Lambe, with styli with scarcely perceptible spinulation, and the species fragilis Frstdt. and indistincta Frstdt, to be treated hereafter, which have slightly spinulous to quite smooth styli. An even transition is in reality found from species with strongly spined styli to such ones where the styli are quite smooth. According to this the genus therefore would scarcely be maintainable. There is, however, another character which sharply separates the species of the genus Dendoryx (or Myxilla, as it ought now to be called) into two groups, whether they have smooth or spined styli; the fact being that in some species ancorse occur, in others chelae arcuatae (see the account of these spicules in the introduction). This character is a quite sharp one without transitions of any kind, and in my opinion great stress may be laid on it for systematic purposes. As L. leptoderma Tops, is a species with arcuate chela;, the genus containing species with these chelss will accordingly get the name Lissodendoryx, while in the genus Myxilla, with the typical species rosacea Lieberk. only species with ancorpe remain. The name of Lissodendoryx is not exactly a good one by the new limitation of the genus, but it cannot be rejected. Otherwise the fact seems to be that most J/vuv7/tf-species have spined styli, and most ' Lissodendoryx-species smooth ones. 1. L. lobosa n. sp. PL V, Fig. 5. PL XV, Fig. 4 a— c. Erect, irregularly lobed-branched. The dermal membrane very thin. The skeleton a somewhat diffusi and irregular reticulation, chiefly of polyspicular fibres with single transverse spicules between them. Spicula: Megasclera; the skeletal spicules acanthostyli with rather dense spinulation o-ji — o-jOij"'"'. the dermal spicules tylota o-jj—o-jo"""; microsclera of one form, chela: arcuato? 0-038 — 0-044""". PORIFERA. II. ,-- The two specimens in hand of this species have an erect, lobed-branched form. Below they are attached to shells of arenose Foraminifera. The few stubby and irregular lobes or branches issue from about the upper half. The height is 32""". The consistency is very soft and loose. The colour (in spirit) is a dirty grayish yellow. The surface, in the present state of the sponge, is shaggj I projecting spicules, but this seems partly to be owing to damaging; in the undamaged sponge 1 sup- pose it to be finely shaggy. The dermal membrane is a transparent and very thin film, but it is wanting to a great extent. Pores are found in the dermal membrane in tin- common way; they were seen from quite small ones to a diameter of o-22'n,n. Osculawere not observed, which was perhaps due to the loose consistency and collapsed state of the sponge; as far as I was able to see, some large canals were running longitudinally through the branches and lobes, which canals probably run to the top, where the oscula should accordingly be found. The skeleton. The dermal skeleton is formed by dermal spicules supporting the membrane. When a piece of the dermal membrane is seen from above, the spicules are seen to lie horizontally in it, partly scattered singly, partly in bundles here and there, but on account of the state of the material, I have not been able to observe the relation between the dermal skeleton and the main skeleton. I suppose that in the undamaged sponge more or less projecting bundles of dermal spicules are found. The main skeleton is a somewhat diffuse and irregular reticulation. Long polyspicular fibres are found, especially in the branches; they run longitudinally through the branches in a tolerably regular way, but are loose and not very conspicuous. Transverse fibres are not found between them, but only quite irregularly placed spicules, almost all of which are placed singly. Regular meshes, therefore, are not formed, and the whole skeletal net gives a rather irregular picture. The ends .if the fibres bend towards the surface, or they give off short branches passing to the surface. Spongin is found in the nodes of the skeleton, but only to a very slight amount. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli ; they have often a small head-swelling, so as to approach subtylostyli. They are evenly curved, often a little irregularly. They are evenly and middle long or rather long pointed, but the outermost point itself is most frequently short pointed. The spinulation may be somewhat varying, but is most frequentlj rather dense, and the spines are fine; they continue to the very point. The length is rather constant, from 03] ■ i;V")""", and the thickness is ca. cooS — o'Oi2""". Very few developmental forms were seen, the finest ones were already somewhat spined. 2. The dermal spicules are tylota; the}' are straight and have at either end a longish, rather slight swelling. Their size is rather constant, the length 0-25 0-29' and the thickness about croo5""n. The two ends of the tylota are not quite equal, one end having a more distinct and more marked swelling than the other; this is owing to the fact that the shaft is aol oi equal thickness throughout the length, but tapers somewhat towards one end, and so the swelling this end becomes more marked; this again is connected with the fact that the tylota are secondarily diactinal. b. Microsclera; these are of only one form, chelae arcuatae. The chelae have a curved shaft, the curve of which is .strongest in the middle, while the ends, on the Othei hand, are a '. recurved. The tooth is elliptical and rather narrow, and of the same length as the alae; the lower edge of the alse is rather much indented, so that, when seen from the side, they have a somewhat tooth-like form. When the chela is seen from the side in a certain position, we shall often yet a quite 156 l'ORIFERA. II. wrong impression of the ake, as well in this as in many other arcuate chelae, if it is not sufficiently magnified; the fact is that only the foremost, refolded edge is seen distinctly, and the ala seems to be more or less claw-shaped. When, on the other hand, the magnifying powers are sufficiently high, the contour of the ala is seen distinctly, as given in Fig. 4 c, PI. XV. The length of the chela is 0-038 — 0-044""", and the thickness of the shaft is 0-0024— o-oo50mm; this variation of the thickness of the shaft is most dependent on the way in which the chela is seen, from the front or from the side, as the shaft is not cylindric, but rather much compressed. Developmental forms in different stages were seen in small numbers. Locality: Station 10, 640 24' Lat. N., 280 50' Long. W., depth 788 fathoms, a fragment; station 27, 640 54' Lat. N., 550 10' Long. W., depth 393 fathoms, two specimens and a fragment. The stations are situated in the Denmark Strait and in the Davis Strait. 2. L. Sophia Frstdt. PL V, Fig. 6. PL XV, Fig. 5. 1887. Esperia Sophia Fristedt, Vega Exp. vetensk. Iakttag. IV, 451, PL 25, figs. 30 — 32. Erect, leaf-shaped. The surface smooth. The dee mat membrane a thin film, on the pore side supported by pillars of dermal spicules, but here without horizontal spicules, while on the oscular side it has only horizontal spicules. Oscula and pores each on their own side. The skeleton diffuse and quite irregular, formed by single spicules and loose bundles. Spicula : Megasclera: the skeletal spicules acan- thostyli 0-4.4 — o-juS""", the dermal spicules sfrongyla with finely spined, sometimes smooth ends, 0-27 — o-j4mm; microsclera of one form, chelce arcuatce 0-028 — o-oj4""n. We have two somewhat damaged specimens of this species; both of them ' are erect and leaf- shaped; one specimen is seen to have been attached by its lower edge, which shows a surface of attachment; this surface occupies almost the whole breadth of the leaf, so that the sponge has not been narrowed to a stalk. Fristedt says of the species that it is «massive, probably thickly incrust- ing hard objects . Whether the question is here of the sponge forming below a basal expansion, or Fristedt has made a mistake in his interpretation, I am not able to decide. The largest of ray specimens is 50™™ high, 8omm broad, and ca. nmm thick. The consistency is middle hard and little elastic. The colour (in spirit) is dirtily brown. The surface is smooth, without projecting spicules. The dermal membrane is a thin, transparent film, supported by pillars of dermal spicules which do not project through it, or only to a very slight degree; on the pore side it is otherwise without spicules, while on the oscular side it has horizontal spicules. Pores and oscula belong each to their own side; the pores are closely gathered, so that the membrane gets a sieve-like appearance; they are generally of a circular form, and were measured of sizes from 0-035— 0-15™™. Pores may also be found on the oscular side. Oscula are found scattered and in rather small numbers on the opposite surface; they are only to be seen with difficulty, as the opening itself is not seen; the fact is that the membrane tonus a quite low and almost not at all projecting spout or cone, at the top of which the lobate aperture is found. While the horizontal spicules of the membrane otherwise are scattered on the PORIFERA. II. j-- oscular side, they are here gathered to bands running to the top of the cone, and the cone being, it were, a little twisted, the mentioned hands get a somewhat spiral course. The skeleton. The dermal skeleton. In the dermal membrane of the pore side no horizontal spicules are found; the membrane of the oscular side, on the other hand, is provided with horizontal, scattered, rather close-lying dermal spicules; on the pore side the membrane is supported by more or less perpendicular pillars of dermal spicules; they spread in a penicillate way and support the mem- brane, but they do not pierce it, or almost not at all. These spicules support the membrane between the pores, and sometimes a few quite horizontal spicules may reach from them into the membrane On the oscular side no pillars of dermal spicules are seen, but the membrane is resting on the main skeleton below, the styli of which may project a little here and there. When on the oscular side here and there a group of pores is found, the membrane is in this place constructed quite as on the pore side and is supported by pillars. The main skeleton is quite irregular; longer fibres are not found, and meshes are scarcely to be spoken of, as the spicules more particularly convey the impression of being irregularly scattered, their ends, however, are generally seen to meet. They are partly lying singly, partly in loose bundles of few spicules. In the nodes of the skeleton a distinct mass of spongin is found. Spicula: a. Megasclera. i. The skeletal spicules are acanthostyli ; they are generally some- what curved, and the curve is almost always situated near the head-end; they are evenly and rather long and finely pointed. The spinulation may be somewhat varying, but is generally rather scattered, and the spines are fine; they continue to the very point. At the head-end a few spines are placed more close together. It is especially in the upper two thirds of the style, below the closer placed spines of the head-end, that the spines are highly scattered, in the lower part they are generally again closer together. The spines of the lower part are frequently directed somewhat backwards. Their length is rather constant and is between 0-44 and o^iS™"1, and the thickness is O/OIO— OOl28min. 2. The dermal spicules are strongyla; they are more or less curved, more rarely straight Their ends, which may sometimes be very slightly swollen, are generally finely spined, but the spinulation ma\ become almost indiscernible, and they may also be quite smooth. They are somewhat fusiform, being thickest in the middle. The two ends are not equal, one being always a little thicker than the other. Their length is 0-27— o-34mm, the thickness is 0-007— o-oiomnl. Quite lew developmental forms were seen. they were distinctly monactinal and showed no spines, b. Microsclera; these are of only one form, chela; arcuatae; they resemble the chelae of the | tig species, hut are finer, and their terminal parts are not recurved. The tooth is elliptical, broadest below and of the same length as the alae; the lower edge of the alae is not much indented, and therefore they have no tooth-like appi in this respect the chelae approach the palmate chelae. The length is 0-028— ;v)m,:\ ami the thickness of the shaft is ca. iroo2m"'. The chelae are found throughout the sponge, hut especially in the dermal membrane. As I have examined a piece of Fristedt's type specimen, 1 have been able to identify species with certainty. It seems to he closely allied to til eding one, hut all three forms of spicules show distinguishing characters. IS8 PORIFERA. II. Locality: 62 u' I. at. X., 190 36' Long. W., depth 1142 fathoms. (The cruise of the fishery investi- gation steamer Thor , 1903). Gcogr. distr. Fristedt has the species from East Greenland, 650 30' Lat. N., depth 130 fathoms. 3. L. fragilis Frstdt. PI. V, Figs. 7—8. PL XVI, Fig. 1 a— g. 1SS5. Hastatus fragilis Fristedt, Kgl. Sv. Vet. Akad. Handl. Bd. 21, Xr. 6, 35, Taf. Ill, Fig. 6 a— h. The form somewhat varying, forming thick incrustations, or the sponge irregularly massive or erect, formed like an irregular, thick leaf. The surface grooved and finely shaggy. The dermal mem- brane a very thin film, in some places with erect bun dies of dermal spicules, in other places with spicules horizontally in the membrane. Oscula scattered, or found only on one side. The skeleton an irregular, polysplenia)- reticulation of triangular, quadrangular, or polygonal meshes; in the leaf-shaped specimens longer fibres may be found. Spicu/a : Megasclera: the skeletal spicules very finely spined or smooth styli 0-29 — 0-40""". the dermal spicules tornota 0-20 — o-268mm; microsclera of two forms, cliche arcuatm o-oj/ — o'ooo""", sigmata 0-018 — o-o2j""". Of this species we have a rather large material, but it consists mostly of fragments or much damaged specimens. To judge from this material the species may vary somewhat with regard to its (niter form. Sometimes it forms only an irregular, thick incrustation, but the larger specimens seem always to rise from the tmderlayer, growing upwards and assuming a more or less irregular leaf-shape. These leaf-shaped specimens are always rather thick. The specimens are attached to plate-shaped Bryozoa or have their bases expanded over bottom material of different sorts. The largest specimen which seems to be the lower part of a leaf-shaped individual, has a greatest extent of ca. 45"™, and a thickness of ca. iomm; a rather regularly leaf-shaped fragment is of similar dimensions. Entire speci- mens of the sponge are evidently much larger. The massive specimens are smaller. The colour (in spirit) is a lighter or darker grayish yellow. The consistency is rather firm, but brittle and fragile, and this is surely the reason, why the specimens are in a so highly damaged condition. The surface is grooved, about as in M. incrustans, and it is finely shaggy from projecting spicules. The dermal membrane is a very thin and transparent film; it rests on the skeleton below, and is partly supported by this skeleton, partly by special dermal spicules. Pores are found in the membrane, often closely gathered, so that pore-sieves are formed. Their size was measured to 0-047 — o-29mm. In the markedly leaf-shaped specimens the pores seem only to occur on one side, while oscula belong to the other side; in the irregular specimens, on the other hand, there is no definite localisation of oscula and pores. Oscula are seen as circular openings scattered on the side that has no pores; they are of an average size of :"m. The sponge is set through very closely with canals running from one side to the other, not, however, running straight across, but sinuous and branched in different ways. Some of the largest of these canals open on the oscular side as oscula, and in the oscular canal a great many smaller canals are seen to open. When the dermal membrane is removed from the opposite side, a great many close- standing incurrent canals are here seen. The skeleton. The dermal skeleton may be somewhat different in different places of the sponge; PORIFERA. II. I59 in many places, especially, perhaps, where pore-sieves are found, there are penicillate bundles of dermal spicules supporting the dermal membrane. Along the edge of the pore anas they may become short fibres branching into the area among the pores, and then they are more or less, often quite recumbent in the membrane. They do not reach quite into the middle part of the area, and lure the membrane is consequently without spicules. In other places dermal spicules are only found scattered in the skin, both singly and in bundles. In these last places the membrane is resting on the main skeleton below, the spicules of which project, and also where projecting bundles of dermal spicules are found, projecting skeletal spicules are seen in them The main skeleton, by far the greatest part of it. is a polyspicular, irregular, and rather close network. No distinction can be made between primary fibres and secondary ones; the meshes are triangular or quadrangular or quite irregular. The fibres, as mentioned, are most frequently polyspicular, but the meshes are also here and there bounded by single spicules. In the leaf-shaped specimens longer fibres may be found running in the longitudinal direction of the 1' af, but else without any regularity. Otherwise, longer fibres are not found in the skeleton, and in the leaf-shaped specimens no fibres are found passing perpendicularly to the surface or spreading towards the surface in a penicillate way. Spongin is found in the nodes of the skeleton, but to a very slight amount; moreover, it is white and clear, and consequently only to be seen witli difficulty. Spictila: a. Megasclcra. i. The skeletal spicules are styli; they have a curve, most fre- quently a rather slight one, nearest to the rounded end, while the other part of the needle is straight or almost straight; more rarely the curve is more even through the whole length of the spicule, or it is irregular. The point is even and middle long. The styli may be slightly spined or smooth. In the spined ones the spines are only found in a short part at the upper end, and the spines are so small as only to make the surface finely gritty; a few scattered, also very small spines are often found farther down the styli. This slight spinulation may become quite minimal, and it may entirely dis- appear, so that the style becomes smooth. In the material in hand there are no instances of smooth and spined styli occurring in equal numbers; either all the styli are spined, and smooth ones occur onlv as exceptions, or the case is the reverse. The length varies from 0-29 — o-_|o",m, the smallest length occurring more rarely, and the thickness is ca. o-on — croi7mm, the longest ones being far from always the thickest ones. Some finer to quite fine deyelopmental forms occur; they seem to be finely and dispersedly gritty from spines almost through their whole length, and this not only in the specimens that have almost no smooth styli, but also in those with almost exclusively smooth styli. The finest stages observed had a length of o-26mm with a thickness of onh O'OOIA""". -'. The dermal spicules are tornota; they are straight, only rarely a little irregularly curved. Their two ends are not equal, one is a little thicker, and it is rounded with a quite slight mucro, the other, on the other hand, forms a rather short point, so that the needle might be interpreted as a short-pointed style'). The length is 0'20— o-268ram, and the thickness 0-003- -0005""". The finer these spicules ,ue, the more marked is the difference between their two ends, and I have seen quite few fine develop- mental forms with the thin end rather long pointed, b. Microsclera; these are oi two forms, ch arcuatse and sigmata. 1. The chela- have a curved shaft with the strongest curve in the middle; u The several compound terms (tornostrongyla etc >. which may often he used advantageously, .ire here, as often else. not sufficiently characteristic; tin- name tli.it would best describe the present form should. I suppi j^o porifera. ii. the tooth is most frequently elliptical, but may vary rather much in form, be more narrow or broader, and rounded or straight cut off at the end; it is of the same length as the alse; the lower edge of these is somewhat indented, so that they get a tooth-like form, but they may be somewhat varying in form, as upon the whole the chela may vary rather much in appearance. In a few individuals peculiar deformities occurred rather frequently. The size of the chela is somewhat varying, the length is between 0-037 — o-o6omm, the smallest ones occurring most rarely; the thickness of the shaft is ca. 0-005 — o-oo7mm, it is not cylindrical, but somewhat compressed. Developmental forms at different stages, the youngest ones quite fine, were seen in rather small numbers. 2. Sigmata are distinguished by being very fine; they are otherwise of the common form and more or less contort. Their length is 0-018 — o-025mm, they are so fine, that their thickness is only ca. o,ooo7IIin]. Both forms of the microsclera occur through the whole sponge and are rather frequent in the dermal membrane. Remarks: Although I have not examined Fristedt's type specimen, I take the determination to be quite sure, as description, measures, and figures agree very well, thus especially the figure of the fine sigma. Fristedt does not mention that the styli may be finely spined, but this feature is easily overlooked, or he may have had a specimen with almost exclusively smooth styli. The speci- men figured by Fristedt I suppose to be the lower part of a larger individual. The name fragilis is well adapted to the brittle consistency. Locality: Station 85, 630 21' Lat. N., 250 21' Long. W., depth 170 fathoms; 66c 20' Lat. N., 25° 12' Long. W., depth 96 fathoms (Wandel); 620 53' Lat. N., 90 06' Long. W., depth 245 fathoms, 620 26' Lat. N., 40 49' Long. W., depth 228 fathoms, 620 36' Lat. N., 30 21' Long. E., depth 198 fathoms (Ad. Jensen, the cruise of the Michael Sars» 1902); at the northern end of Nolso, depth ca. 100 fathoms (Th. Mortensen). The localities are situated in the Denmark Strait, round the Faroe Islands, and at the western coast of Norway. Geogr. distr. The species is hitherto known from the Koster Islands at the coast of Bohuslan, depth 95 fathoms. It is thus distributed from the Denmark Strait to the coast of Bohuslan, and its bathymetrical range is from 95 to 245 fathoms. 4. L. diversichela u. sp. PI. V, Fig. 9. PI. XVI, Fig. 2 a— h. More or less irregularly thick leaf-shaped? The surface almost smooth. The dermal membrane a thin film supported by penicillate bundles of dermal spicules. The skeleton a polyspicular, irregular reticulation, forming triangular to quadrangular or irregular meshes, here and there longitudinal fibres. Spieula : Megasclera: the skeletal spicules rather densely spined acanthostyli 0-J4 — 0-429""", the dermal spicules tornota o-2ji\ — o-j<\""": microsclera of four forms, chela- arcuata of three forms, large ones 0-047 — o-oyi""", middle ones this, be taken to be more or less leaf-shaped, presumably with a broad base. The largest fragment has a height of 45""" and a thickness in the leaf-shaped part of N""". The colour (in spirit) is light yellowish. The consistency is rather firm, but brittle. The surface is almost smooth or only very slightly shaggy, and the shagginess is chiefly due to the large chelae, lying closely in the membrane. The dermal membrane is a thin film, supported by bundles of dermal spicules. The pores are closely gathered in sieve-like areas, often so close as to be separated only by thin strings; their size was measured to 0-09 — 070mm. Oscula are circular openings of a diameter of ca. 2mm. To judge from the material, the pores are situated on one side, and oscula on the other. The skeleton. The dermal skeleton consists of bundles or short fibres of dermal spicules spread in a penicillate way ; they issue from the skeleton below and reach mostly horizontally into the mem- brane. When a piece of skin is cut off and seen from above, the fibres are seen especially to issue from the edge of the subdermal cavities or the incurrent canals, over which the pore areas are ound then they pass into the area and send off branches into the strings between the pores. Also on the oscular side the construction of the dermal skeleton is similar, the skin over the numerous canals that pass the sponge about transversely being also supported by short fibres. The membrane is, moreover, filled with chelae, especially of the largest form. The main skeleton is chieflv constructed as in fragilis, and forms an irregular network of triangular, quadrangular, or polygonal irregular meshes. It is generally polyspicular with rather many (4 — 8) spicules alongside. No distinction can be made between primary- and secondary fibres; here and there a little longer fibres may be found running in the longi- tudinal direction, but continuous fibres are otherwise not formed. When a section placed in xylole is examined, all the canals are distinctly seen, as the membranes coating these canals are highly filled with cheke. Spongin is found in the skeleton, but it is white and clear, and only a very small amount is present. Spicula: a. Megasclera. 1. The skeletal spicules are acanthostyli with rather dense spinu- lation. They are evenly and slightly curved, and have a middle long point, which is, for a greater or smaller part, without spines. Their length varies from 034 — o'429m"', the shortest ones being rather rare; the thickness is ca. 0-0128 — o'02i,nm. A few developmental forms were found, the finest ones, oi a thickness of ca. croo2'mn, were seen to be finely spined. 2. The dermal spicules are tornota; they are straight or, more rarely, a little irregularly curved. They resemble the tornota in L.fragilis, and - end is a little thicker than the other, which is somewhat longer pointed; in the finer forms this feature is most marked. Their length is 0-238— o-28mm, and the thickness 0*004; o-oo6omm. b. Microsclcra. These are chela? arcuatte of three forms and sizes, and sigmata. 1. The large chelae are very characteristic; their shaft is strongly curved, almost to a semicircle, and the terminal parts are relatively small; the tooth is short and stubby, and the likewise stubby alse are of the same length as the tooth. Thei] size is somewhat varying, the length from 0*047— oi07imm, most frequently it is nearest the latti the thickness of the shaft is 0-0057— 0-Oi4mra ; this variation in thickness is due to the fact that the shaft is not cylindrical, but somewhat flattened, and therefore .1 transverse section of it is elliptical. Of this chela some developmental forms were found; the younger these forms are, the more flattened is the shaft, so that it may be quite thin, almost band-shaped. A transverse section shows, howi that a thicker part is running through the middle of it, while the lateral parts are quite thin; then Tli.- [ngolf-Expedition. VI. .• -' l x62 PORIFERA. II. it becomes by degrees elliptical during the growth. In the youngest forms the alae are only seen as a little more marked expansions at either end of the thin lateral parts. The very finest forms are cylindrical. 2. The chela? of the middle form are considerably smaller; they have a rather highly curved shaft; the terminal parts are considerably larger than in the large ones, so that the free part of tiie shaft is only about one third or a little more. The tooth is rather narrow, the alte are of the same length as the tooth, and their lower edge is indented, so that the}- have a somewhat tooth-like form when seen from the side. Their length is o-oi8 — o-028mm, and the thickness of the shaft is ca. o-oo2i — o-oo28m,n. Quite singly chela? are seen that seem to occupy a position midway between these chelse and the preceding form. 3. The smallest chela is of a peculiar and very characteristic form. It is highly curved, and the terminal parts are so large, that the free middle part of the shaft is less than a third of the whole length; but when the chela is seen from the front, the terminal parts are, on account of the curving, seen a little from the end and therefore shortened, so that in a frontal figure the terminal parts and the free part of the shaft will be of about equal length. The tooth is narrow and shorter than the alae, and their lower edge is almost not indented. The chela is very small, its length is 0010— o-oi5mm, and the thickness of the shaft is ca. o-ooiomm. On account of the form of the alae this chela approaches the palmate chelse, but on account of its strong curving and the narrow teeth it is more properly referred to the arcuate chelae. 4. Sigmata are of the common form, and are more or less contort, up to one fourth of a turning. They are very varying in size, the length from 0023 — o-o85mm, and the thickness proportionally from o-ooi — o-oc>3mm. The microscleres occur throughout the sponge, especially in all membranes; the large chela, as mentioned, is particularly con- spicuous both in the dermal membrane and in the membranes of the canals. Locality: Station 10, 640 24' Lat. N., 280 50' Long.W., depth 788 fathoms; station 85, 630 21' Lat. N., 25 21' Long. W., depth 170 fathoms; 62° 36' Lat. N., 30 21' Long. E., depth 198 fathoms (Ad. Jensen, the cruise of the « Michael Sars 1902). Four fragments in all. The localities are situated in the Denmark .Strait and off the western coast of Norway. 5. L. indistincta Frstdt. PI. V, Fig. 10. PI. XVI, Fig. 3 a— h. [887. Hastatits indistinctus Fristedt, Vega Exp. vetensk. Iakttag. IV, 444, PI. 25, figs. 13— 19. Massive, more or less loba/e. The surface slightly grooved or smooth, very finely shaggy. The dermal membrane not especially thin, supported by erect or more or less recumbent bundles of dermal spicules. Oscula scattered, few. The skeleton an irregular, mostly polysplenia r reticulation ; longer fibres passing towards the surface may be found; sometimes the reticulation is more diffuse and unispicular. Spieula: Megasclera: the skeletal spicules slightly and dispersedly spined, sometimes smooth, sfyli 0-35— 0-50""", the dermal spicules tornota or toruostrongyla 0-20 — o-2gmm; microsclera of three forms, cliche arena fee of two forms , large ones o-oiS—o-ojj""" , small peculiar ones o-ooS—o-oif""1, sigmata 0-026 — 0-05""". This species has chiefly a massive, more or less lobate form. It may grow expanded on the substratum, and from the expanded part, which grows to a considerable thickness, round projections PORIFERA. II. l63 or lobes may rise; but most frequently it seems, when rising, to assume a somewhat compi form, always, however, forming some stubby lobes. Thus the roundlobed form is the most marked character of its exterior. The specimens in hand, none of which are quite entire, reach a rather considerable size; a specimen of a massive and more expanded form has a greatest extent of ca. ioo'nm, and a greatest height of ca. gom,n, the thickness of the expanded part is ca. 30mm. The largest of the more erect and compressed specimens has a breadth of 125°™, a thickness of ca. 4omm, and a height of ca. 8o'm". Thus these specimens are considerably larger than that of Fristedt, which had a length of 40""", a breadth of i5mm, and a thickness of 2omm; according to these measures his specimen must have been of massive form. The colour (in spirit) is whitish yellow. The consistency is rather brittle and only little elastic. The surface is very slightly grooved; only here and there the grooves were a little deeper, in other places the surface is quite smooth. We have here in reality the same structure as in several Myxiila- and L/s'sodc//ec[es with grooves separated by ridges, only that here the grooves are very shal- low or disappearing and the ridges little conspicuous1)- The surface gets, however, a somewhat net- like appearance, the subdermal cavities situated under the grooves shining through with a darker colour. The surface is in most places very finely shaggy from projecting spicules. The dermal mem- brane is a somewhat transparent, not especially thin film. It is supported by bundles of dermal spicules, which may be highly recumbent. In most places, especially where pores are found, the membrane gets a peculiar appearance, about as mentioned under J/, incrustans. The subdermal cavities, which shine darkly through the membrane, are here distinctly seen; sometimes they are somewhat roundish, sometimes more irregularly sinuous, and separated by the parts of tissue between the canals, which appear whitish. The darker areas over the subdermal cavities, however, are subdivided into smaller areas, fibres or parts of tissue stretching from the edges of the subdermal cavities below the suspended membrane. The pores are then situated in the areas that arise in this way. Therefore the sponge, as to its surface, is very similar to such specimens of J/ incrustans as have a tolerably smooth sur- face. The pores are lying in groups in the mentioned areas of the dermal membrane, and thereby these areas become pore-sieves. The pores are round, or, when placed close together, irregularly polygonal; their size was measured to 0-03 — o-23'nm, sometimes they were still larger. Oscula are scattered and only few in number; they are round or sometimes more irregular openings, surrounded by the dermal membrane with a sharp edge. They are very varying in size and reach at most a diameter oi ca. 4""". The skeleton. The dermal skeleton consists of penicillate bundles of dermal spicules, which pass out from the skeleton below and support the dermal membrane, piercing it. Where the membrane is lying over the parts of tissue separating the subdermal cavities, the question is only of bundles, which are perpendicular or more or less recumbent. From the edges of the subdermal cavities shorter, a little branched fibres run into the suspended membrane, where they end, spread in a penicillate way, and finally fibres run under the suspended membrane, or more loosely lying dermal spicules are found in the strings of tissue that pass under it, and in both cases more or less elect, penicillate bun project from here through the membrane, Moreover, the membrane is highly filled with microsclei '1 I suppose the structure of the surface in these species to be owing to the strength of the dermal membrane; thus M. incrustans has a thin dermal membrane tnd deeper grooves, M. ftmbriata a thick dermal membrane and a smooth sur- face, ami in both respects tin- present species occupies a position about midwaj between these two species. PORIFERA. II. The dermal spicules project only very little through the membrane, so that the surface is only very slightly shaggy. The main skeleton is a rather close, but irregular reticulation. It is mostly poly- spicular; fibres may be found running chiefly upwards or towards the surface. They may be somewhat different with regard to their number of spicules alongside, but most frequently they have but few spicules, and they are rather loose. Coherent transverse fibres are not formed, but are only represented by single spicules or spicula-bundles. These transverse spicules are placed rather irregularly, and so the net uf meshes is upon the whole irregular. Frequently longer fibres are not found, but the skeleton forms a quite irregular network of a somewhat diffuse character. The meshes are then irregular, also often triangular; in this case the network is often more unispicular, so that the whole may convey an impression of being quite diffuse with scattered, mostly single spicules without any formation of a distinct network. A distinctly observable, but rather slight amount of spongiu is found in the nodes of the skeleton. Spicala: a. Alegasclcra. i. The skeletal spicules are styli; they are slightly and dispersedly spined, sometimes quite smooth. They are most frequently slightly curved, sometimes a little more or irregularly so; the point is rather short. The spiuulation may be very varying; at most the styli are dispersedly spined, and then all transitions are found to quite smooth ones. Then differences in this respect may be found in different individuals; in some spined styli are almost exclusively found, and of these most belong to the most highly spined ones, while quite smooth ones are only rarely seen; in other individuals the smooth styli are predominant, and the spined ones are then very slightly spined. Their length varies from 035 — o-50mm and the thickness from crooS — croi4mm. There may be some difference with regard to the length in different individuals; in the material in hand the fact seems to be that in individuals where the spined styli are predominant, they attain a little greater length than in individuals with predominant smooth styli. Also the thickness may show a little difference in the different individuals, a few ones especially having frequently thinner styli than the others. 2. The dermal spicules are tornota or tornostrongyla; sometimes one or both ends are a little swollen, so that they approach tylota or tylotornota. They are straight, more rarely they may be somewhat irregularly curved. Their length varies from 0-20 — cr29mm and the thickness from ca. 0-0035 — o-oo57mm. Some difference may be found in different individuals, so that in some the dermal spicules are upon the whole a little longer than in others. As mentioned, there is most frequently a little difference between the two ends, one being a little more swollen and especially a little more rounded than the other. A few developmental forms were seen, which were quite monactinal with the thin, end pointed. In a single individual almost all the dermal spicules had ends a little swollen, and these subtylota had not rarely uniform or almost uniform ends. b. Microsclera. These are chelae areuatae, some peculiar, very small chelae, and sigmata. 1. The chelae arcuatse have a regularly curved shaft; the tooth is elliptical and rather long, and the alae, of the same length as the tooth, are rather narrow and therefore tooth-like; the chelae, therefore, are very similar to ancorae, and by a superficial examination they may be confounded with aneorae, but by a closer exa- mination they are seen to be chelae. This chela varies much in size, its length is 0-018— o-044mm, and the thickness of the shaft is 0-0018— o,oo4'nm. The largest sizes are less frequent. 2. The small PORIFERA. II. *5 peculiar chelae are, on account of their smallness, only to be examined with difficulty. They consist of a curved shaft, which has, at either end, a number df teeth or tooth-like processes. Their number seems, at all events most frequently, to be about ten. The shaft is not smooth, but looks, as if it were rather highly rugged. By sufficient high magnifying powers it is seen, however, that the shaft may better be called lobate, as it has on either side a row of lobes, and these give to it its rugged appear- ance. The lobes are placed in such a way, that in the middle of the shaft they are nearest to the dorsal side, and when the chela is seen in a lateral position, the lobes in the middle are turned a little backward; farther out on the shaft the lobes by degrees turn to the opposite side, and the) seem to pass evenly into the tooth-like processes of the ends, becoming at the same time longer. The terminal parts of the shaft, from which the teeth issue, are a little expanded. The teeth may he some- what varying in size, often the middle tooth or the middle teeth may he longest. The chela varies somewhat in form, the shaft especially may be more or less curved. The described construction i.s only to be distinguished under high magnifying powers. As mentioned, these chelae are very small, their length is ca. crooS — o-oi5mm, and the thickness is ea. o-ooi""n. — 1 have placed this peculiar spicule to the cheke; 1 suppose that the rows of lobes of the shaft correspond to the alge, and then the recurving part must correspond to a tooth, but nothing can otherwise be said as to the relations of this spicule to the other cheke. 3. Sigmata are of the common form and more or less contort; their length varies from 0-026 — 0'05mm, and the thickness about from 0-0018 — o-O030mm. By far most frequently the size is near to the larger limit. All the microscleres are frequent in the membranes through the whole sponge and also present in large numbers in the dermal membrane. Remarks: As I have examined Fristedt's type specimen, the identification is sure. Fristedt has not seen the construction of the small chela, which he therefore mentions as the small sigma, anil so he gets of microscleres one chela and two forms of sigmata, while in reality there are two forms of cheke and only one form of sigmata. It is easily understood, on account of the smallness of this chela, that he has not interpreted it correctly. His name indistincta shows that he has found nothing characteristic in the species; but now this name is rather unhappy, as the species, on account of the small chela, is especially distinct. When he says of the dermal spicules: The\ ate often curved . this expression is quite correct, as in his type specimen these spicules especially frequently occur as curved; on the other hand, the figure of this spicule is quite a mistake with regard to oik- end. Fristedt gives the length of the styli to n'35"""; his type specimen belongs to those where the smooth styli are predominant, and the styli are also, in conformity to what has been said above, com- paratively short; I have measured them, however, of lengths of up to 0^17""". Locality: Station 34, the Davis Strait, 65° 17' Lat. N., 540 17' Long. W., depth 55 fathoms; the Davis Strait, 65° 22' Lat. N., 540 02' Long. VY., depth 60 fathoms (Wandel); the Davis Strait, depth too fathoms (Th. Holm); Hekla Harbour, depth 5—12 fathoms (the East-Greenland Expedition iN..i About ten specimens or fragments in all. Geogr. distr. Fristedt has the species in one specimen from Spitsbergen, depth 60 fathoms. The species seems to he a native of more shallow water, as it is only known from depths of 5- fathoms. j66 porifera. ii. 6. L. complicata Arm. Hans. PL V, Fig. ii. PI. XVI, Fig. 4 a-g. 1885. Reniera complicata Armauer Hansen, The Norwegian North-Atlantic Exp. XIII, Spongiadse, 7, PI. I, fig. 8, PL VI, fig. 8. 1885. Myxilla grisea Armaner Hansen, ibid. 12, PL I, fig. 3, PL VI, fig. 9. [887. Clalhria corallorhizoidcs Fristedt, Vega Exp. vetensk. Iaktt. IV, 460, PL 25, figs. 73 — 77, PL 29, fig- 23. Erect, bush-shaped, with more or less, often highly anastomosing brandies. The surface shaggy. 'Flic dermal membrane a very thin film with partly projecting, partly horizontal dermal spicules. The skeleton a somewhat irregular network; primary, polyspicular longitudinal fibres are found . bending gradually toivards the surface; they are connected by irregularly placed, mostly single transverse spicules. Spicula: Megasclera: the skeletal spicules smooth styli 0-42 — cr68""", the dermal spicules strongyla to subtylota 0-22— 0-40""": microsclera of three forms, chel'\:N:l"". b. Microsclcra; these are of three forms, chelae arcuatae and sigmata of two sizes. 1. The chelae arcuatae have chiefly j5s porifera. ii. the same form as the large chela? in L. diversichela ; they have a highly curved shaft, scarcely, how- ever, so highly curved as in the mentioned chela, the terminal parts are small in proportion to the length of the shaft, tooth and alee are stubby. Their length is 0-04— o-c>58mm, the smallest lengths being rare, and the thickness of the shaft is 0-005— o-oi2mm. Also m tms chela the shaft is broadly elliptical in section, and this is the cause of the variation in thickness. Developmental forms at different stages were seen, the development is as mentioned under the large chelae in diver sichela. 2. Sigmata of the small form; these are rather characteristic; they are highly curved, often almost in a circular manner, the points, however, being generally curved a little more inward; they are plane. The sigmata are rather small, but their size is tolerably constant, the length is 0-017 — o-023mm and the thickness about o-ooimm. 3. Sigmata of the large form; besides the small sigmata, which occur in great numbers, a larger form is found only occurring very sparsely; they have the common sigmaform, the ends are rather highly curved in a somewhat hook-like manner, and they are more or less contort. Their length is 0-042 — o-055mm, and the thickness is ca. o-oo2mm. As mentioned, they occur in very slight number, so that they might be supposed to be extraneous bodies; but as they show a distinct form and may be found in any specimen by a closer examination, they belong doubtless to the species. They must not be confounded with the youngest developmental forms of the chela, to which they bear a superficial resemblance. They seem to occur especially in the dermal membrane. The other microscleres occur through the whole sponge and especially in the dermal membrane, where in some places the chelse occur rather closely. Ronarks: As I have examined type specimens of the quoted species, established by Armauer Hansen and Fristedt, I have been able to make a sure identification. As the original name, under which it has been established, is complicata, this name must be used. Armauer Hansen's description and figures of complicata might raise a doubt as to the specific identity; as, however, the type specimen I have examined is the present species, and as Armauer Hansen's figure of the exterior also absolutely belongs to this species, I have thought it best to take up the name; most of the spicules described and figured by Armauer Hansen do not agree, and either he must have con- founded them with the spicules of an Axinellid, as might well be done, as the species has some outer resemblance to an Axinellid, or else there must have been an abundance of extraneous spicules in his preparation. /.".tilify: Station 141, 630 22' Lat. N., 6° 58' Long. W., depth 679 fathoms, (bottom temperature ^-o°6C); station 143, 620 58' Lat. N., f 09' Long. W., depth 388 fathoms, (bottom temperature -^o°4 0; 700 32' Lat. N., 8° 10' Long. W., depth 470 fathoms (The East-Greenland Expedition 1891—92); ca. four- teen specimens in all. The localities are situated north of the Faroe Islands and south of Jan Mayen. Geogr. dish-. The species has been taken before by the Norwegian North-Atlantic Expedition, and, according to the statement, at its station 84. For this station is stated a bottom temperature of 6°5 C. .\s now the two Ingolf-stations from which we have the species show negative temperatures, and as also the locality south of Jan Mayen, according to the investigations of the Ingolf , must be a negative one, it is not probable that the species occurs at a bottom with a temperature of 6°5 C. To be sure, station 84 is situated at the very border between the warm and cold area, and so the species might possibly be found there; but station 84, according to the list of the zoological stations, is no PORIFERA. II. 169 zoological one; on the other hand, station 87 is a zoological one, and its temperature is -ffiC; a confounding of these stations may therefore possibly have taken place. Fristedt has the species from the Baffin Bay, 68° 08' Lat. N., 580 17' Long. W., depth 169 fathoms. Accordingly the species is known from the Baffin Bay and the North-Atlantic south of Jan Mayen and north of the Faroe Islands, with a bathymetrical range from 169—673 fathoms, and it must be supposed to be a native of the cold area. 7. L. vicina n. sp. PI. V, Fig. 12. PI. XVII, Fig. 1 a— f. Bush-shaped? with anastomosing branches. The surface shaggy. The dermal membram very thin, partly with projecting bundles of dermal spicules, partly with horizontal ones. Tin skeleton cm irregular, mostly polyspicular net-work ; longitudinal fibres ace found, connected by irregularly placed spicules and spicula-bundles. Spicitla: Megasclera: the skeletal spicules smooth styli oy/—om86mm, the dermal spicules tylota 0-32 — o-jS"""; microsclera of three terms, chela arcuata 0-034— o-osjmm, sigmata of two forms, small ones o-oij — o-ujj""", larger ones o'02t\ — o-ojj""". Of this species we have only two fragments; they show, however, that the species has an exterior, quite similar to that of L. complicata, as they consist of some anastomosing, flattened branches. The larger fragment has a longitudinal extent of 6omm. The colour (in spirit) is yellowish white, and the sponge has the same net-like appearance as the preceding species. The consistency is rather firm and somewhat elastic. The surface is very distinctly, but somewhat dispersedly, shaggy from projecting spicules. The dermal membrane is a very thin film, partly resting on the skeleton below, partly sup- ported by dermal spicules. With regard to oscula and pores the facts are as in the preceding species. The pores are for a great part situated in sieve-like areas; they were measured from quite small ones up to o-47mm. Oscula are round openings of sizes from c/6mm to ca. i-^mm; but also in this species pores and oscula may pass into each other with regard to size. The skeleton is in every respect constructed in a similar way as in /. complicata. The dermal skeleton consists of dermal spicules, partly forming bundles or short fibres that may project a little or lie horizontally in the membrane, partly being found singly scattered in the membrane, but upon the whole the dermal skeleton is little developed; further spicules from the main skeleton project. The main skeleton is an irregular, niostlv polyspicular network; fibres are found, running chiefly in the longitudinal direction, but branching irregularly, and being upon the whole rather irregular. Between them spicules and spicula-bundles are found irregularly placed, and bundles issue to the surface. The longitudinal fibres do not bend towards the surface in any regular way, and as well in longitudinal sections as in transverse ones the skeleton conveys an impression of greater irregularity than in com- plicata. This may, however, be owing to the fact that we have only irregular fragments with copious anastomoses, a thing that influences the regularity of the skeleton. Spongin is found in the fibres. Spicula: a. Megasclera. i. The skeletal spicules are smooth styli; they are somewhat curved, almost always nearest to the head-end. and the curve ma\ be more or less strong, sometimes it is a little irregular. They have an evenly tapering, rathei long point. Their length is 071- The Ingolf-Exi>edition. \ I -.mm j-0 PORIFERA. II. most frequently midway between these limits, the thickness is croiS — o-025mm. Also in these styli a widening of the axial canal is seen at the upper end, and this widening is generally found a little below the end of this canal. 2. The dermal spicules are tylota; they are comparatively long and thin with well-developed end-swellings, and they are straight, sometimes slightly curved. Their length is 0-32 — o-38m,n, and the thickness 0-0028 — o-oo35mm. The two ends of the tylota are not quite equal, the shaft is in one end a little thicker, while the swelling is here comparatively smaller, whereas in the other end it is a little thinner, and the swelling is larger, often almost globular. To judge from a few developmental forms, it is, however, this end which is originally pointed, b. Microsclera; these are of three forms, chelae areuatae and sigmata of two sizes. 1. Chelee arcuatas are of the same form as the cheke in L, complicata ; the shaft is rather highly curved, the ends are relatively small, and tooth and alse are stubby. The length is 0034 — o-057ram. The shaft is somewhat flattened, and in section flatly elliptical, its thickness, from the side and from the front, is ca. 0-0028 — o-oo8mm. A few develop- mental forms were seen. 2. Sigmata of the small form have most frequently a more common sigma-form as in the preceding species, they are comparatively small and fine, and they are plane. Their length is 0-017— o-023mm and the thickness at most o-ooiomm. 3. Sigmata of the large form; also in this species a larger sigma occurs, but in rather small numbers; it is of the common type, more or less contort, 0-028 — o-033mm long and ca. o-ooi4mm thick. The microscleres are found throughout the sponge and in the dermal membrane, where the large chela is especially frequent. As is shown by the description, this species is very closely allied to the preceding one, but is distinguished from it by sure characters; these distinguishig characters are especially the longer styli, a different form of sigmata, and, above all, a different form of the tylota. Locality: Station 19, 6o° 29' L,at. N., 340 14' Long.W., depth 1566 fathoms. The bottom tempera- ture was here 2°4 C. It is an interesting fact to notice that while the preceding species is a native of the cold bottom, the present species, which is so closely allied to it, but is surely distinguished, belongs to a bottom with positive temperature. The locality is situated in the southern Denmark Strait. 8. L. stipitata n. sp. PL V, Fig. 13. PL XVII, Fig. 2 a— e. Erect, stalked, club-shaped, somewhat compressed. The dermal membrane not especially thin, sup- ported by bandies of dermal spicules and also provided with horizontal spicules. The skeleton dendritic ; from the stalk polyspicular fibres pass up through the sponge, branching and anastomosing. Spicula: Megasclera: the skeletal spicules smooth styli /rjg—o-6j""". the dermal spicules tornota o-ji—o-j&'S"""; microsclera 0/ one form, chela arcuatce o-oj2 — o-c/j""". This species is markedly club-shaped; it consists of a rather thin, cylindric stalk, which is below attached to the substratum by a small basal expansion. The stalk is of equal thickness throughout its length, and above it carries a. head which is somewhat compressed and may best be described as irregularly cordate. This part is compressed in such a way, that one side is convex and the other flat or a little concave. The edge is rather sharp. The smallest specimens are only little or not at all compressed. The largest specimen is 45™" high, of which the stalk makes ca. 15™™ and the upper part PORIFERA. II. j-j ca. 30™"; the breadth of the leaf-shaped part is 24""", and the thickness ca. 10"""; the thickness of the stalk is only i'5mm. Then we have specimens of decreasing sizes, the smallest one with a height of 9""", of which the stalk makes 2-5m,n, and the thickness of the upper part is 2mm. All the specimens are attached to larger or smaller stones. The colour (in spirit) is dirtily brownish gray. The consistency of the tissue itself is soft, but the skeleton makes the sponge rather firm and elastic. On account of the peculiar softness of the tissue, the sponge contracts much in drying, and also in spirit it seems to be highly contracted. The surface is damaged in most specimens, so that its character cannot be decided from these .specimens. To judge from tolerably entire individuals, ends of fibres project, and in the protuberances formed in this way spicules project; also the longitudinal fibres lying under the skin give rise to keel-shaped ridges se- parated by grooves, so that the surface gets upon the whole a slightly grooved appearance. In undamaged specimens a dermal membrane may be separated as a not especially thin, intransparent film. /' were not seen. Oscula : here and there, to be sure, a few scattered openings are seen, but these, I think, are only due to damaging. In the best preserved specimen, on the other hand, a spout-shaped oscnlum is found on the top of the sponge. It consists of a small, somewhat conical spout formed by the dermal membrane; it has a height of i-$mm and a somewhat similar breadth. In the spout, formed by the dermal membrane, the dermal spicules are lying very close, parallel to the longitudinal axis. In the other, less well preserved specimens, this oscnlum is not found, but everything indicates that it has been present, some perpendicular canals being found in the tipper part of the sponge, and some thin-skinned parts with openings being seen in the uppermost edge. The mentioned specimen shows only one oscnlum, but in other specimens several oseula seem to have been found. The skeleton. The dermal skeleton. The fibres running from the main skeleton to the surface end in bundles of dermal spicules spread in a more or less penicillate way, which bundles cause the projections of the surface and rise through them. As the fibres are not perpendicular on the surface, but directed upwards, the projecting bundles are recumbent, when the dermal membrane is seen from above. The dermal membrane, which is suspended between the projections, has, moreover, horizontal dermal spicules, partly singly scattered, partly here and there in bundles. Besides, the membrane is copiously provided with chelae. The main skeleton is of dendritic type. In the basal expansion spicules are found closely packed without any order, but chiefly parallel to the underlayer. Towards the middle they rise upward, and the expansion passes into the stalk. Neither are the spicules in the stalk arranged quite as in a fibre, some of them being placed more 01 less obliquely; chiefly, however, they are placed in the longitudinal direction. Especiall) in the central part of the stalk they are directed longitudinally, while the more scattered arrangement is found in the peripheral layer; outer- most a looser layer is found with spicules turned in all directions, and from this layer spicules project, so that also the stalk becomes shaggy. Dermal spicules were not seen, cither in the stalk or 111 the basal expansion. Not till the stalk passes into the upper body, the spicules are arranged so as to lie quite parallelly in the fibres. In the basal expansion and the stalk the spicules are shorter than in the other parts of the body; upward in the stalk the) become graduallj longer. Where the stalk passes into the upper body, it begins to divide, and the fibres continue up through the sponge, copi- ously branching in a dendritic manner and also frequently anastomosing, branches continually bend out towards the surface, and end in the bundles oi dermal spicules of the skin. All the fibres are I72 PORIFERA. II. polyspicular, and the thicker ones have many spicules alongside. The first and thickest fibres issuing from the stalk have an average thickness of o-6mm, and the thinnest branches going to the surface are ca. o-05mm thick. Spongin is found in the fibres through their whole length, coating them, perhaps, with an exceedingly fine layer, but it is white and clear and not easily observed; it is most copious in the stalk. Spicidn: a. Megasclera. i. The skeletal spicules are smooth styli; they are slightly curved, ami the curve is generally situated nearest to the head-end. They taper quite imperceptibly towards the head-end; towards the point they are somewhat tapering, but the point itself is short. Their length is between 0-39 and 0-63""", and the thickness is 0-012 — o'Oi6mm; the longest ones are not always the thickest ones. In the basal expansion and in the stalk the styli, as mentioned, are considerably shorter, only 0-208 — 0-35"™; upward in the stalk they become gradually longer, and in the upper part of the stalk they reach o-47mm. 2. The dermal spicules are tornota; they are straight, or slightly, and then frequently a little irregularly, curved. Their ends are most frequently slightly swollen, they are about rounded and end with a little muero. The ends are not quite equal, one being a little thinner than the other and generally a little more pointed. Their length is 0-31 — o-488mm, and the thickness O'co67 — croio""". b. Microsclera; these are only of one form, chelse arcuatse. They have a somewhat curved shaft, the lower edge of the alse are only little indented, and therefore the ala is not much tooth-shaped; the tooth is narrowly elliptical, of the same length as the ala;, and there is a small tuberculum broadest downward. The chela must be called arcuate, but it forms a transition to the palmate ones. The length is 0-032 — o-045mm, the thickness of the shaft is ca. 0-003 — o-oo5rani; the shaft is not cylindrical, but more or less compressed. A few developmental forms were seen as thin staves recurved at both ends. The chelse occur through the whole sponge, but they are especially numerous in the dermal membrane. Embryos. In most specimens embryos were found copiously scattered in the tissue. They are globular or a little flattened, of a diameter of up to o-48mm; on account of their white colour they were easily discerned in the tissue. No spicules were found in them. Locality: Station 10, 640 24' Lat. N, 280 50' Long.W., depth 788 fathoms (bottom temperature 3°5 C), two, mostly denuded, skeletons ; station 104, 66° 23' Lat. N., 70 25' Long. W., depth 975 fathoms (bottom temperature -f- i°i C), one large and two small specimens; station 105, 65° 34' Lat. N., 70 31' Long. W., depth 762 fathoms (bottom temperature -=- o°8 C), four specimens; 62° 30' Lat N., i° 56' Long. E., depth 275 fathoms (bottom temperature negative), a small specimen (Ad. Jensen, the cruise of the Michael. Sars> 1902). As is seen from the list, the three localities are from the cold bottom, and according to this the species must be supposed to be a native of the cold area; the fourth locality, station 10, on the contrary, is situated on the south side of the ridge between Iceland and Greenland, and it is positive. Now it is to be remarked, however, that from this locality we have only two almost quite denuded skeletons, and so there is a possibility that these specimens have been dead, and have been carried to this locality as dead. This is also indicated by another fact; all the other specimens with the exception of a few ones that have been broken off, are attached to the stone which serves for their attachment, whereas the two specimens from station 10, although they have the basal expan- sion of the stalk undamaged, are loosened from their substrata. PORIFERA. II. if? Note. This species has a skeletal structure similar to that of the species ternatensis established by Thiele (Abhandl. d. Senckenberg. nat. Gesellsch. XXV, Heft IV, 953), and by him referred to the genus Hamigera. The genus Hamigera with the typical species hamigera O.Schmidt was by Top- sent (Resultats des Campagn. scient. du Prince de Monaco, Fasc. II, 102) referred to the Ectyonina on account of its skeletal structure. Thiele I.e. says that, after having examined sections of Schmidt's type specimen, he cannot follow Topsent in this, as he finds sty li and strongyla to he intermingled. I have also examined a piece of Schmidt's type specimen, kindly sent me by Dr. Marktanner, and although the examination of a small, dried fragment must necessarily be somewhat deficient, as, on account of contraction, it gives only a rather indistinct idea of the skeleton, I must nevertheless admit Topsent to be right. The fibres consist almost exclusively of strongyla, only a few snbtvlostvli being found here and there in them; on the other hand subtylostyli are seen to project from the fibres. When upon the whole a group Ectyoniiuv is admitted, Hamigera, according to my examinations, must doubtless be referred to it. Thiele's species ternatensis, of which it is expressly said that the fibres almost exclusively consist of styli, while at the surface radiating bundles of dermal spicules are found, is surely not to be referred to Hamigera, but must be a Lissodendoryx, When Thiele as the prin- cipal difference between Dendoryx (= Myxilla) and Hamigera mentions the want of a regular choano- somal skeleton in the latter, this character cannot be used as a generic distinction, as reticular and dendritic skeletons ma)- be found in the different species of as well Lissodendoryx as other genera. When Thiele says, in a foot-note: «Vermutlich werden noch mehrere <■ Lissodendoryx -Arten in die Gattung Hamigera gehoren , this is cpiite correct according to his view, but according to what has been propounded here, such species will just have to be kept in the genus Lissodendoryx. lophon Gray. The form somewhat varying, incrusting or massive, but not rarely erect, cylindrical or branched, or, finally, more or less regularly leaf-shaped. The skeleton a most frequently irregular, mostly : spicular reticulation, without any distinction between primary and secondary fibres ; sometimes lo fibres are present. The dermal skeleton zvell developed, consisting of bundles oj dermal spicules, partly lying horizontally in the membrane, partly erect and penicillate. -/ rather slight amount of spongin is found. Spicula: Megasclera: the skeletal spicules styli, most frequently more or less spincd, sometimes smooth, the dermal spicules diactinal, strongyla or most frequently tylota. oft en est with slightly spincd ends; microsclera anisochela palmatcB of a characteristic form with the smaller end provided with a spur, ami almost always bipocilla, which may be somewhat -carving inform. The genus lophon is an especially distinctly characterized genus, and the distinct characters are found in the microsclera. To be sure, chelae of the same form as in lophon and bipocilla are again found in Pocillon, which is the pendant of lophon among the Ectyonina; but surely these two genera are also, in spite of the grouping, very closely allied to each other. The peculiar chela is always present in lophon. while bipocilla may be wanting in a lew cases, and therefore the chela is the form of microsclera most characteristic of the genus. This chela is never found in any otliei ,-( PORIFERA. II. genus, with the only exception of the above mentioned Pocillon1). The chela is a palmate anisochela, whose smaller end is considerably smaller than the larger one; from the axial recurving of the smaller end a sharp spine or spur issues. The chelse may in some species occur in two different sizes. In a few species they may also form rosettes, and then, as is generally the case, only the large chelse form rosettes, while the small ones, when such are found, are never gathered in rosettes. Neither are bipocilla known outside the genera Ioplio)i and Pocillon2). The author who first mentions these bodies is Bowerbank; his description of them, like his descriptions of the chelae upon the whole, is defi- cient, and he calls them in different places and according to the different positions in which he finds them nnipocillated and , bipocillated bihamates or bijDocillated anchorates>. Gray calls them bipolicated anchorates>, I suppose on account of a misreading of Bowerbank. Vosmaer (Niederl. Arch, fur Zoologie, Suppl. Band I, 1881, 82) says that they are probably a modification of sigmata. Ridley and Dendy calls them bipocillate spicules or ■ bipocilli 3), and of the peculiar bipocillnm in Tofihon chelifer they say that they are inclined to regard it as a much modified anisochela. Top- sent says also in 1901 (Resultats du Voyage du S. Y. Belgica, Spongiaires), under Iophon radiatus that the bipocilla must be regarded as modified anisoehelse, but his reason for this opinion, that their smaller end shows a fine dentation, is scarcely of any importance. Thiele, finally, in 1903 (Arch, fur Naturgesch. 1903, I, 389) calls the bipocilla anisoehelse without any further explanation. — The common form of the bipocilla had never been correctly described till the appearance of Wilson's work, mentioned below. Generally, as by Ridley and Dendy, they are described as consisting of a shaft with a cup-like expansion at each end. Wilson in 1904 (Mem. of the Mus. of comparative Zoology at Harvard College, XXX, Nr. 1, 143 — 154, PI. 19, fig. 6 b— e, PI. 20, fig. 6 a et c, fig. 15 a, c— f) gives for the first time a thorough description of the construction of the bipocilla in the species treated by him; here for the first time a correct and exact description is given, together with good figures. The author does not say that the bi- pocilla are to be regarded as chelae, but he calls the peculiar bipocilla in I. chelifer and lamellata chelate bipocillus . — The bipocilla are in reality somewhat modified anisoehelse, and the principal modification is that a tooth only is developed in one end, which may be designated as the upper end. The bipo- cillnm, in its common and typical form, consists of a curved shaft, which has always an exceedingly fine brim on either side. At the lower end the shaft is so much recurved, as to form about a right angle with the middle part of the shaft, but the curve is round and even; in this recurved part the lateral brim of the shaft is broader, and therefore this part has a somewhat spoon-like form. At the upper end the lateral brim is also a little widened and forms a pair of small alae; then follows, as usually, n thin connection with the tooth, formed by the shaft alone; the tooth is a comparatively ') Carter (Ann. Mag. Nat. Hist., Ser. 5, IX. 291, PI. XI, fig. 16 e, f) mentions and figures a very small chela occurring in his Esperia loevis, which might seem to be of the Zo^/ion-type, as Carter also remarks. Esperia lavis is evidently a •le, and it has a typical vl/y<:lf from the curve a short spur. At the larger end a longish tuberculum is found; at the lower end the tuberculum appears together with the spur as a pear-shaped body. The cheke vary much in iize, and at the same time the dimensions are a little altered, the larger end of the smaller chela? PORIFERA. II. being comparatively larger than that of the larger cliche. The cliche may also vary somewhat in form in different individuals, thus sometimes the alse of the larger end may continue far down towards the other end, and may even be united with the alse of this end, which feature, however, musl regarded as a monstrosity; in such cases also the tooth passes far down towards the tooth of the lower end. The length of the cheke is between o-Ol6 and 0-036""", and the breadth is OOO57— O-OII"" 2. The bipocilla are of the common form described in the preliminary remarks of the genus; the slight indentation of the edge of the lower end is rather distinct under high magnifying powers. The shaft is somewhat expanded through its whole length, and above it forms a narrow ala on eithei >ide. The bipocilla are somewhat varying in size, as well in one individual as in different individuals; in the larger ones the indentation of the edge of the lower end is distinctly discernible; the inden- tation often continues rather far up. Sometimes, especially in some individuals, monstrous forms oi the bipocilla occur, the most common monstrosity being that the tooth of the upper end is split, often quite irregularly, and also the alse may be separated from the shaft and assume peculiar forms. The length of the bipocilla varies from O'OoS — o-oi4mn\ but sometimes it does not exceed o-Oiimm. The microscleres are found both in the tissue and in the dermal membrane, perhaps in larger numbers at the latter place. Sometimes the cheke seem to be present in larger numbers than the bipocilla, some- times the reverse is the case. Embryos. In some individuals embryos were found King in the tissue in large numbers. They are globular, and their diameter is ca. o\30mm. Of spicules the examined specimens showed only cheke. which are thus the first occurring spicules. In the spicula-preparations, however, just from specimens with embryos, some needles are found gathered in a bundle-like manner, which have surely belonged to the embryos. These spicules are straight or slightly curved; they are highly thickened at the head- end, thus approaching subtylostyli, and they are comparatively strongly spined; they were measured to a length of 0-12 — o-i4'"!". This species is characteristic and well bounded, when both the outer form, the spicules, and the structure of the dermal skeleton is considered. — I regard the determination as sure. Vosmac specimen evidently is not regularly cup-shaped, what is seen parth from the figure, partly from the expression a cup-shaped great mass . It is also to be noticed that his figures 79 and 80 evidently represent spicules not belonging to the sponge; fig. 80 looks as a J/ivvz/V-anisochela. — The species mentioned by Levinsen (Dijmphua-Togtets zool.-bot. Udbytte, 300, im as Esperella pica, according to m\ examinations, is not this species, but a new one, see under I.frigidvs p. [83. The species m< by Fristedt I.e. as Esperia nigricans, to judge from a fragment examined by me. is identical with the present species, as is also shown by his remark that the sponge may be leaf-shaped; when he says that it is generally an amorphous mass, it is, I suppose, on account of his having had only fragments before him. Locality: This species has been obtained in a great man) specimens, mostly, however, fragments. Station 1, 62 30' Lat. X., 8 21'Long.W., depth 132 fathoms: station 3, 63 35' LaL N., Long. \\\, depth 272 fathoms; station 4, 64 07' Lat N., 11 12' Long. W., depth 237 fathoms; station 7. 63 13' Lat. X., 13 41' Long. \Y., depth 600 fathoms; station 27, 64 54' Lat N., 55 [o'Long.W., depth 393 fathoms; station 32, 66 35' Lat. N., 56 38' Long. W., depth 318 fathoms; station 13. 6ic 1 >' Lat. X., jSq PORIFERA. II. ti'Long. W., depth 645 fathoms; station 53, 63° 15' La t. N., 15 07' Long. W., depth 795 fathoms; sta- tion 54, 630 08' Lat. N., 15 p' Long. W., depth 691 fathoms; station 55, 630 33' Lat N., 150 02' Long. W., depth 316 fathoms; station 73, 620 58' Lat. N., 230 28' Long. W., depth 486 fathoms; station 81, 61° 44' Lat. N., 270 00' Long. W., depth 485 fathoms; station 85, 63° 21' Lat. N., 250 21' Long. W., depth 170 fathoms; station 92, 640 44' Lat. N., 32° 52' Long. W., depth 976 fathoms; station 93, 641 24' Lat. N., 350 14' Long. W., depth 767 fathoms; station 95, 65° 14' Lat. N., 300 39' Long. W., depth 752 fathoms; station 96, 2 \ Lat. X., 290 00' Long. W., depth 735 fathoms; station 98, 65° 38' Lat. N., 26° 27' Long. W., depth 138 fathoms; station 115, 70° 50' Lat. N., 8° 29' Long. W., depth 86 fathoms; station 143, 62 58' Lat. N., 7" 09' Long. W., depth 388 fathoms (bottom temperature -=- o°4 C). It has further been taken in the Den- mark Strait at 65 29 Lat. N., 28° 25' Long. W., depth 553 fathoms (Ryder), and at 63J 15' Lat. N., 90 35' Long. W., depth 270 fathoms (Wandel). Finally it has been taken at 64° 56' Lat. N., n° 48' Long. W., depth 115 fathoms, and 620 30 Lat. N., i° 56' Long. E., depth 275 fathoms (Ad. Jensen, the cruise of the Michael Sars 1902). The greatest number of specimens were taken at station 95. The localities are situated over about the whole Ingolf-territory, in the Davis Strait, the Denmark Strait, south of Iceland, at Jan Mayen, between Iceland and the Faroe Islands, and at the coast of Norway. Geogr. distr. The Barent Sea, at depths of 145, 170, 192, and 220 fathoms (Vosmaer 1. c); Fri- stedt I.e. has it from north of Spitsbergen, 790 47' Lat. N., 11° 15' Long. E., depth 100 fathoms, and at South-Greenland, 590 33' Lat. N., 430 25' Long. W., depth 120 fathoms. The species is, accordingly, widely distributed between ca. 500 Long. W. and 50° Long. E. and between ca. 59^ and 8o° Lat. N. Its bathy- metrical range is from 86 fathoms (at Jan .Mayen) to 976 fathoms (the northern Denmark Strait). The species seem to be a native on bottom with positive temperature; it was taken, however, at station 143 with a temperature of -^ 04 C. 2. I. dubius Arm. Hans. H. VI, Figs. 2— 5. PI. XVII, Fig. 4 a— e. 1885. Reniera dubia Armauer Hansen, The Norwegian North-Atlantic Exp. XIII, Spongiadae, 6, PL II, fig. i, PI. VI, fig. 7. 1887. Esperia Pattersoni Fristedt (11011 How.), Vega-Exp. vetensk. Iakttag. IV, 448. The form most frequently branched, more or less free or somewhat coalesced, cylindric or flattened branches issuing from a base; sometimes the sponge is more irregularly lobate or forms incrustations. surface smooth or 'eery slightly shaggy. The dermal membrane an easily separable, thin film, pro- vided with a reticulation oj iter mid spicules, and supported by peuicillate bundles op such spicules. Osculu scattered. The skeleton a close, irregular, partly polysplenia!-, partly unispicular reticulation. Spicula: Megasclera: the skeletal spicules acanthostyli 0-208 — 0-274""", the dermal spicules tylota to strongyla with spiued ends o-ii) — 0-25""" ; microsclcru of tie" tonus, auisochehe falmatie of the Jophon-type u-uij— 0-031""" . id foe ilia o-ooj—o-oi 0 """. This species may, according to its mode of growth, have a somewhat varying appearance. t grows especially on Hydroids, and is found on many different species, and on erect Bryozoa. It may then form common, more or less thick incrustations, the thicker ones may be irregularly cushion- shaped, or they send off more or less stubby lobes. By far most frequently, however, it forms more ORIFERA. II. or less tree branches that may here and there be attached to the branches oi the Hydroid, but may also be quite free; thus, as to its mode of growth, it reminds of Esperiopsh Normanni, and the branched form is the one that is typical and most characteristic of the species. The branches may be variously formed, thicker and more irregular and flattened, or thinner and cylindric. They may branch in different ways, and they may be more or less coalesced, sometimes in such a way as to form plate- shaped parts. When the species is growing on a different substratum, it may form a common incrus- tation, but this seems to he a rare case; we have only one specimen of this form, growing on a large shell of Modiola modiolus. The largest specimens in hand, which may be described as irregular, longish cushions, have a greatest extent of 75""". The most frequent length of the more or less branched specimens is ca. 25—55""". The consistency is of middle firmness and somewhat elastic, the free branches are soft and flexible. The colour (in spirit) is a lighter or darker brown to grayish black or almost quite black; in some of the jars the sponge has kept its original grayish yellow colour, or has only turned a little darker. The surface, when undamaged, is smooth or at most very slightly shaggy- The dermal membrane is a thin and transparent film, but it is distinct and separable; it has a special skeleton of horizontal dermal spicules, and it is supported by more or less perpendicular pillars of dermal spicules; these spicules may be a trifle projecting. The pores are round; in most places they are lying close together in the meshes of the dermal reticulation, several pores in each mesh. Thev are rather small, their size being measured to between 0'023 0-083' ■ Oscula arc little conspicuous, but they may almost always be found by a closer examination. .Most frequently they are more or less hidden at the base of the branches or in the clefts between these, or at other places in folds of the surface. They form most frequently irregular openings, the thin membrane round them being split into lobes; in these lobes the dermal spicules are closely gathered parallel to the longitudinal axis of the lobe, that is to say, with the ends towards the opening. Most frequently the oscular aperture leads into a larger or smaller cavity just under the membrane. Oscula are present in only rather small numbers. The skeleton. The dermal skeleton is of a similar structure as in I. piccus, and forms a beauti- ful, in most places rather close, reticulation of polyspicular fibres. The meshes are triangular, quadran- gular, or polygonal. The fibres have rather main- spicules alongside, but in this respect they are varying, and accordingly of varying thickness; generally thicker fibres an- found having a sinuous course, chiefly in the longitudinal direction of the sponge; between these fibres then thinner ones are found, and sometimes only a few spicules are seen together, or the meshes are divided by single spicules. As in the preceding species the fibres are almost always of some length so as to contribute to the formation of several meshes, more rarely they are so short that thev only reach from one fibre to the next; the thickest fibres are generally the longest. This structure gives to the dermal reticulation a peculiar, characteristic appearance; tin appearance 111. i\ otherwise be somewhat varying, especially with regard to the closeness of the net 1 if meshes and the thickness of the fibres. The dermal mem- brane is supported b\ perpendicular or more or less recumbent pillars of dermal spicules, spread in a peuicillate way; these spicules may project quite slightly through the membrane, so that the surface becomes very slightly shaggy. The pillars are geueralh only of the length of one spicule. The skeleton is a close, quite irregular reticulation, in which there is no distinction between primary and PORIFERA. II. mdary fibres. The network is partly polyspicular, partly umspicular, from one to four or five spicules being found alongside. Some long fibres are found, especially distinct in the branches, in which they run longitudinally; they are not thick, however, scarcely above o-03'mn. In the nodes of the skeleton a little copious, white, and clear mass of spongin is found, but no spongin is seen in the dermal skeleton. Spicula: a. Megasclera. i. The skeletal spicules are acauthostyli; they are either quite straight or slightly curved. The point is rather short, at most middle long. The spinulatiou may be- somewhat varying, the spines being more or less powerful, but they are most frequently rather scat- tered ; also in this feature, however, some variation is found. Next the spinulatiou is remarkable by the fact that the spines are almost always a little closer gathered at the upper end, and that here most frequently a few larger spines are found; especially in the thinner styli the spines are distinctly more closely gathered at the upper end. The length varies from cr2oS — o-274mm. The thickness is very varying, from 00057 — 0-0128"""; this variation in thickness is in no proportion to the length; the thinner ones being fully as long as the thick ones. Developmental forms of the styli, down to exceedingly fine ones, are rather frequent; they are of about the full length; the finer ones are quite slightly spined, they resemble most frequently subtylostyli, a little swelling being seen just below the upper end, presumably corresponding to the closely gathered spines later found here. 2. The dermal spicules are tylota or strongyla with spined ends and of a similar form as in the preceding species; they are slightly and evenly curved ; they may be about equally thick through their whole length, but most frequently they are thickest in the middle; there may be a little difference between the two ends, but most frequently they are almost quite equal. Their length is 0-19 — o-25mm, and the thickness 0-005— O'OOj"1"1. Developmental forms were rather frequent, in which one end was always thinner than the other, b. Microsclera are anisocheke palmate of the Iophon-typt and bipocilla. 1. The aniso- c h e 1 x are of the common form, the tooth is of about the same breadth as the alas and most frequently a little shorter; the larger end has a long, narrow tuberculum, at the smaller end a shorter tuberculum is found joining the spur. The chelse may be somewhat varying with regard to the length of the free part of the shaft. Their total length varies from 0-017 — 0-03 imm, the breadth is proportionally 0-006—0-01 28mm. vSome developmental forms at different stages were seen; the youngest ones are fine staves recurved at the ends; the spur of the smaller end, which in reality is only a peculiar develop- ment of the tuberculum, is already begun at an early stage. 2. The bipocilla are of the common form, the indentation of the edge of the lower end is only seen with difficulty; their length is 0007 — 0-Oiomm. The microscleres are found throughout the tissue and especially in the dermal membrane. With regard to the spicules this species is chiefly distinguished from /. piceus by having upon the whole smaller spicules, and by some difference in the spinulatiou of the acauthostyli; when this fact is regarded in connection with the exteriors and modes of growth of the two species and with the feature of their oscula and pores, the species are with certainty to be distinguished from each other. - As I have had a type specimen of Armauer Hansen's Reniera dubia for examination, I have been able to identify the species with certainty. Armauer Hansen has not seen the micro- scleres at all, and without an examination of the type specimen a determination would have been quite impossible, as I think that Armauer Hansen's always bad drawings of spicula may be said [FERA. II. to reach their climax in the figures of the spicula of this species. Also of Fristedt's Esperia Patter- son I have examined one of the author's specimens, and have found his species to be identical with dubiiis, only the spicules are a little more spined than in my specimens. How the relation is between this species and those of Bowerbank, I cannot say with certainty; the question can only be of the two species nigricans and Pattcrsoni, ( >f Pattersoni I have examined a specimen sent me by the Rev. Mr. Norman; according to this specimen, this species seems to have thinner styli, they did not exceed o-oo8mm in thickness. Bowerbank figures the dermal spicules as spined all over, but in the description he savs terminally spined ; in the specimen I have examined only the ends were spined. /. nigricans I have not seen; the style figured by Bowerbank does not show the spines more closely gathered at the upper end, but this feature is not always distinctly marked in dubiiis either. None of the two species, on the other hand, seems to have the characteristic exterior so frequent in dubius. Topsent (Rev. biol. du Nord de la Fr. VII, 19) unites Bowerbank's two species, which is perhaps correct; neither is it precluded that the present species may prove to be identical with them; this question can only be decided by a close examination of all Bowerbank's specimens, and for the present dubius must be kept up. Locality : We have a very great number of the species, but only from the sea round the Faroe Islands, where it must be very commonly found, and southeast of Iceland. At the north end of Nolso, depth ca. 100 fathoms; six miles northwest of Kalso, depth 60 fathoms; thirteen miles northwest of Borona;s, depth 30 fathoms (Th. Mortensen); 64° 27' Lat N., 133 27' Long.W., depth 84 fathoms 1 Ad. Jensen, the cruise of the Michael Sars» 1902). Geogr. distr. Between Spitsbergen and Norway, at 72 27' Lat. X., 350 01' Long. E., depth [36 fathoms (The Norwegian North-Atlantic Exp.); the Vaigat Islands at Spitzbergen, depth 60 fathoms (Fristedt I.e.). The species seems to be a native of rather shallow water, its liatln metrical range b( 30 — 136 fathoms. For the locality from the Norwegian North-Atlantic Expedition is stated a bottom temperature of ( 1 C. 3. I. frigidus 11. sp. PI. N VI I, Fig. 5a-f. :886 Esperella picca Levinsen, Dijmphna-Togtets zool.-bot. Udbytte, 360, Tab. XXXI, figs. 1, 2 a d. Form? The dermal membrane a thin film with a reticulation oj dermal spicules, an irregular, for a great part unispicular, network. Spicula: Mcgasclcra: the skeletal spicules acantho- styli with same close-set. large spines at the head-end, 0-298 o-jSf"'"; the dermal spicules tylota :. spined ends 2< >""". Developmental forms, down to quite fine ones, occurred in small numbers. 2. The dermal spicules are tylota with ti ably well developed end-swellings; they are most frequently straight; .sometimes the\ may be quite slightly curved; they are about cylindrical. Their length varies from 0-32 | :""", in a few cases the\ may be still a little longer, but most frequently the length is about midway between the two - given, ca. 0-37 '. The thickness is 0*006 o-oo85m,n. In the fully developed tylota no different only a slight one is found between the two ends, but such a difference is found in the developmental forms; the finer they are, the thinner is one end, and its swelling is more longish than that of the [38 PORIFERA. II. other end; in the very finest developmental forms one end is pointed, b. Microsclera ; these are of two forms, isancorae unguiferae and birotuke. i. The ancorae are constructed quite as those of the pre- ceding species, but they have from nine to thirteen free teeth at either end. Also here one or two teeth are found which are connected behind with the shaft; sometimes these teeth coalesce so completely with the shaft, that they are almost not to be traced, and otherwise there is the same irregularity as in the preceding species. In a few cases the shaft is attached in the middle, and the teeth are free all round, but the shaft is also then curved. The length of the ancora is 0-048 — o-o65mm, in a few cases up to 0-074"™, the thickness of the shaft is 0-004 — o-oo58mi". Some developmental forms were seen, showing only a slight swelling at either end, even when the shaft has reached a rather considerable thickness; later slight ribs are formed, which develop into the teeth. 2. Birotuke are of the same structure as in the preceding species, but they have more teeth, from thirteen to ca. twenty; how great the number may be, I cannot decide, as I have not been able to count them with certainty. The length is 0-015 — o-020mm, the breadth across the circle of teeth ca. 0-005'""1, and the thickness of the shaft o-ooiomm. The microscleres are found throughout the sponge and especially in the dermal membrane, in which the ancora; seem more particularly to occur; the birotuke, otherwise, are present in far greater numbers than the ancorse. This species is peculiar by the fact that its skeletal spicules are oxea; another fotroc/wta-species, I. birotulata Higgin, is stated to have diactinal skeletal spicules, which are not, however, oxea, but strongyla ; and the fact seems to be that these spicules are really styli with rounded points. In the present species, on the other hand, the question is of real oxea with quite equal ends, neither show their developmental forms any trace of a monactinal origin. I .(utility: We have a rather copious material of the species, but most specimens are damaged. Station 9, 64° 18' Lat. N., 270 00' Long. W., depth 295 fathoms; station 10, 640 24' Lat. N., 28° 50' Long. W., depth 788 fathoms; station 89, 640 45' Lat. N., 270 20' Long. W., depth 310 fathoms; station 94, 640 56' Lat N., 360 19' Long. W. , depth 204 fathoms; station 97, 650 28' Lat. N. , 2 70 39' Long. W., depth 450 fathoms; station 98, 650 38' Lat. N., 260 27' Long. W., depth 138 fathoms; further it has been taken at 62° 29' Lat. N., 500 17' Long. W., depth 160 fathoms, 6i° 10' Lat. N., 50 46' Long. W., depth 160 fathoms (Ad. Jensen, the cruise of the Michael Sars» 1902). The localities are situated in the Denmark Strait and east of the Faroe Islands. The depths are 138 — 788 fathoms. 3. I. abyssi Cart. PI. XVIII, Fig. 3 a— d. [874. Halichondria abyssi Carter, Ann. Mag. Nat. Hist, Ser. 4, XIV, 245, PI. XIV, figs. 26— 28, PI. XV, fig. 40 a— c. We have not this species in the Ingolf -material, but I have examined a preparation of Carter's type specimen kindly sent me by Dr. Kir ckpa trick. Carter's description of the spicu- lation is chiefly correct. The megasclera are oxea and styli, and the dermal spicules are tylota. The oxea are curved, almost always with a rather sharp bend in the middle, sometimes irregularly; the points are rather long. The oxea have a length of o-6 — o-67mm and a thickness of o-oio— 0-014""". The PORIFERA. II. styli are evenly curved, sometimes straight, with shorter points than the oxea; they are 04.08 — o-49mm long and ca. 0-014 — o-oi6mm thick, and are thus thicker than the oxea. To judge from the preparation there is no reason to doubt that both forms belong to the species. The dermal spicule has been figured incorrectly by Carter; it is a tylote, most frequently quite straight, about equally thick through its whole length, with a distinct swelling at either end. Its length is <)-_x,|N 0-357mm, and the thickness is ca. o-ooj"11". The length of the ancorse is 0-055— 0-06™"' iUK^ the length of birotulae 0-015—001- On the other hand, I am not able to see from the preparation, how main- teeth the ancora- and birotula; have; but it may be decided that Carter's statement of the ancora having six teeth is not correct; perhaps it may have six, but most frequently it has more, and, as usual, the number is not constant. Birotulre, according to what I have been able to count when they were seen from the side have most frequently twelve to fourteen teeth. Both ancorae and birotulse are very similar to the same- bodies in oxeata. The bows mentioned by Carter, which were only found in one of his specimens, are quite surely foreign bodies, neither are they found in the preparation I have examined. This species is closely allied to oxeata, and it shows also conformity to varidens, but it is separated from both these species by the occurrence of both styli and oxea. Locality: 6i3 10' Lat. X.. 2 21' Long. YV., depth 345 fathoms (bottom temperature -i- 1 1 C.i (The Porcupine -Expedition). 4. I. dubia n. sp. PI. XVIII, Fig. 4 a— f. fin rusting. Tin dermal membrane supported by recumbent bundles oj dermal spicules. The skeleton consisting of irregularly situated single spicules, spicula-bundlcs , and here and there fibre-like parts. Spicula : Megasclera: the skeletal spicules styli 0-46— 0-536""", the dermal spicules tylota 0'34~ "-./A""".- microsclera of two forms, isancorce unguifcra with seven to nine fre< teeth . ■ 036 O'ojo""", biro- tulce with eleven to fourteen teeth 0-018 — o-oji""". Of this species we have only one specimen, a quite small incrustation, placed on a dead bala- noid shell. The greatest extent of the incrustation is 14"'"', the thickness does not exceed [mm. The colour (in spirit) is somewhat dark brown. The surfact seems to be smooth. Oscula and pores were not seen. The. skeleton. The dermal skeleton. In the dermal membrane recumbent bundle- o\ dermal spicules are seen, supporting the membrane and forming the dermal skeleton. The main skeleton: As far as I have been able to examine from the slight material, the main skeleton consists of quite irregularly King spicules, mostly single, and lure and there bundles, which may form fibre-like pa but meshes are not formed. A slight amount of spongin is found where the spicules are united. Spicula: a. Megasclera. 1. The skeletal spicules are styli; the) are slightly curved, and the curve is most frequently found nearest to the head-end; sometimes it is more even through its whole length, or a little irregular. They are evenly and middle long 01 rather long pointed. They show the peculiarity that they have almost always some slight spines or rather are slightly uneven at the upper end; this feature is exceedingly slight, often almost imperceptible, but only 1 uite want jqq PORIFERA. II. It ina\ . in a few cases, continue far down the style. The length of the styli is 046— o-536mm, and the thickness 0-0078 — o-onmm. 2. The dermal spicules are straight or somewhat curved tylota; their length is 0-34—0-38""" and the thickness ca. 0-0044""11; one end is always somewhat thinner than the other, and the swelling of this thinner end is more distinctly marked, being as large as that of the opposite end. b. Microsclera : these are isaneone unguifene and birotula;. 1. The an cor a; are of a similar form as in the preceding species, but the teeth are comparatively longer; they have seven to nine free teeth, and one or two teeth united with the shaft. Their length is 0-038— 0-050""", and the thickness of the shaft is 00037 — o-oo50mm. 2. Birotuke have eleven to fourteen teeth at either end; their length is o-oi8— 0-021""", quite few reached a length of oo28m,,!, the thickness of the shaft is ca. o-ooi3"im, the breadth across the circle of teeth is 0-0057— ooo7mm. The microscleres occur through- out the sponge, the ancorre are numerous in the dermal membrane; birotula; are found in predominant numbers. Locality: Station 93, the Denmark Strait, 64°24' Lat. N., 35 14 Long. W., depth 767 fathoms. 5. I. intermedia n. sp. PI. XVIII, Fig. 5 a— d. Incrusting. The surface smooth. The dermal membrane a thin film, supported by recumbent bundles of dermal spicules. The skeleton chiefly consisting of irregularly placed spicules and spiculn- buudles. Spicula : Megasclera: the skeletal spicules styli o~j 57 — 0-48""", the dermal spicules tylota o-j(> — o-j4"""; microsclera of two forms, isancorcr unguiferm with nine to eleven free teeth 0^040 — /rojo'""'. birotulce with fourteen to fifteen teeth O'o/S — 0-021""". We have only one specimen, forming a longish, irregular incrustation on a Homera lichenoides; the length of the sponge is iymm, and the thickness does not exceed 2mm. The colour (in spirit) is a dark grayish brown. The surface seems to be smooth. The dermal membrane is a thin film, supported by bundles of dermal spicules. Pores and oscula were not seen. The skeleton. The dermal skeleton consists of penicillate bundles of dermal spicules, projecting and supporting the dermal membrane. The bundles seem always to be highly recumbent. The main skeleton, as far as I have been able to examine it, consists of irregularly placed spicules and spicula- bundles. It appears that short, loose fibres may be formed, but a net of meshes is not formed. A slight amount of spougin is found where the spicules are united. Spicula: a. Megasclera. 1. The skeletal spicules are styli; they have a slight curve at the upper end, else they are straight; they are almost not tapering, and the point is short or rather short. The upper end is very frecpiently distinctly the thickest part of the style. Their length is 0-357 — o-48n,m and the thickness o-oio — o-oi3mm. 2. The dermal spicules are tylota; they are straight and are not thicker in the middle. Their length is 026— o-34mm and the thickness 0-0050— o-oo64'n". One end is always a little thinner than the other, b. Microsclcra : these are isancora: unguiferse and birotulse. 1. The an corse are of about the same form as in dubia; they have nine to eleven free teeth, and one or two teeth united with the shaft; their length is 0-040 — 0050""", and the thickness of the shaft is 0-004'™". 2- Birotulae; their number of teeth seems to be more constant than in the PORIFERA. II. jqj preceding species, varying only between fourteen and fifteen, and the number was almost always four- teen, only once fifteen teeth were counted. The length of birotulse is o-oi8 — o-02imi", the thickness of the shaft is ca. o-ooi4mm, and the breadth across the circle of teeth is ca. orx/y"". The microscleres are found throughout the sponge, the ancorse are especially numerous in the dermal membrane. Hiro- tulse, as usual, are by far the most numerous. Locality: Between Iceland and the Faroe Islands, 64 56' L,at. N., 11 48' Long. W., depth 115 fathoms (Ad. Jensen, the cruise of the Michael Sars 1902). (hie specimen. 6. I. rotulancora n. sp. Fl.XVIII, Fig. 6 a- g. Fur m/ TJir surface smooth or slightly shaggy. The dermal membram a thin film, support, highly recumbent, often quite horizontal, bundles 0/ dermal spicules. The skeleton consisting of spu and a few spicula-bundles, placed irregularly. Spicula: Megasclera: the skeletal spicules styli oyo — °'jj"""- th'' dermal spicules tylota o'jo — o-^/""": microsclera 0/ two forms, isancorce unguiferm with tic to seventeen teeth, of which either all are free, or one or two art united with the shaft. O'Ojo — 0-040""", hirotulce with nine to twelve teeth 0-018 — 0'0J2""". We have only one specimen, which is, moreover, a fragment, or, at all events, torn nil the underlayer; the sponge, I suppose, has formed a cushion-shaped incrustation, but its form cannot be decided with certainty, and the question might perhaps be of a fragment of a more or less leaf- shaped sponge. The specimen has a greatest extent of 22'n'", and the thickness is ca. 4 'Tl. The colour (in spirit) is light brown. The consistency is middle firm. The surface is smooth or at most slightly shaggy. The dermal membrane is a thin film, contracting when detached; it is supported by bun. of dermal spicules. Pores and oscula were not seen. The skeleton. The slight material in hand has rendered it impossible to examine the skeletal structure as thoroughly as was to be wished. The dermal skeleton consists of bundles of dermal spicules, highly recumbent, often quite horizontal. The main skeleton seems to consist of spicules and, here and there, of spicula-bundles, placed irregularly, and forming neither meshes nor fibres, at most here and there arranged a little loosely in a band-like way. A distinct, but little copious amount of spongin is found where the spicules are united. Spicula: a. Megasclera. 1. The skeletal spicules are styli; they have a curve neai the head-end, and are evenly and long tapering, the outermost point itself is often somewhat stubby. Their length is 0-40— o^s""", the thickness is ca.O'OlO crOl28rain. The longest ones are not the thickest onus. 2. The dermal spicules are tylota; they are straight, only rarely a little curved, and of about equal thickness throughout the length; they are somewhat varying in length, from 0-30 h-ji""", most frequently the length is midway between the given measures; the thickness is 0-004 The tylota taper a little towards one end, and this end, therefore, has a more distinctly marked swell b. Microsclera; these are isancorae unguiferse and birotulse. 1. The ancorse of this species are hit esting by forming a distinct transition to birotulse. They have main teeth, twelve to seventeen, when they are counted all round. When the aucora is seen from the end. the circle of teeth is quite, 01 Io2 PORIFERA. II. almost quite, symmetrical with uniform teeth all round, and the shaft is frequently attached inside the circle of teeth, so that all the teeth are free, and then we have really a birotula with curved shaft; one or two teeth, however, are also often here prolonged and more or less united with the dorsal side of the shaft. Their length is 0-030— o-040mm, and the thickness of the shaft is 0-002 1 — o-oo35mm. A few developmental forms were seen; the beginning teeth are seen in these, while the shaft is still rather thin. 2. Birotula.-; they have nine to twelve teeth at either end, the length is o-oi8 — o-032mm, the latter length, however, is only rarely found, the thickness of the shaft is o-oon— o-ooi4mm, and the breadth of the circle of teeth is 0-0057 — o-oo7'nm. The largest birotuke may have up to thirteen teeth, also thereby showing that they form a transition to the ancora?. A few developmental forms of birotuke were seen; like those of the ancora; they consist of a shaft with a knob at either end. and the knobs showed slight ribs as a beginning of the teeth. The microsclera occur throughout the sponge, the ancorse are frequent in the dermal membrane; birotuke are most numerous. Locality: Rathbone Island off the Liverpool-Coast on the eastern coast of Greenland, ca. jo: 40' Lat. N., depth 94 fathoms (the Amdrup-Expedition). 7. I. polydentata n. sp. PI. VI, Fig. 7. PI. XVIII, Fig. 7 a— e. Erect, more or less irregularly leaf-shaped, or the leaf-shape effaced, passing into a more massive form. TIic surface somewhat grooved, not shaggy. The dermal membrane not especially thin, on the pore side supported by recumbent bandies or short fibres of dermal spicules, and also provided with scattered, horizontal spicules ; on the opposite side only horizontal, scattered spicules are found. Oscula scattered on both surfaces. The skeleton an irregular, mostly polyspicular reticulation, with loose fibres running in the longitudinal direction. Spici/la: Megasclera : the skeletal spicules styli 0-42— 0-5 J""", the dermal spicules tylota 0-25 — o-jj"""; microsclera two forms of birotula-, large ones with twelve to twenty teeth o,020—(T028mm, small ones with nijie to fourteen teeth 0-0128 — owA'""". The largest and finest developed specimen of this species is formed like an erect, rather thick leaf, another, smaller specimen is of a similar form, while a third, also smaller specimen is thicker and more irregular, still, however, with a tendency towards the leaf-shape. According to this, the typical form of the species must be supposed to be as an erect, more or less irregular leaf. The largest speci- men has a height of 70""", a similar breadth, and a thickness of ca. 20mm. The colour (in spirit) is grayish -brown. The consistency is somewhat elastic, but the sponge is rather brittle. The surface is somewhat grooved, but otherwise smooth; the grooves arise in the common way by the dermal membrane being sunk over the subdermal cavities, which shine through as dark areas. This con- struction is distinctly- seen in one specimen, but not in the two others, which are more compact, pre- sumably highly contracted. The dermal membrane is not especially thin, and in places where the sponge is contracted it becomes still a little thicker; it is supported by dermal spicules, partly in bundles, partly scattered. The pores are seen in sieve-like gatherings in the skin above the subdermal cavities, they are really found over the whole surface, but are not conspicuous where the membrane passes the parts of tissue separating the subdermal cavities; they are only found on one surface of PORIFERA. II. jg. tht- sponge. Their common size was measured to between o-o6 and o-iS""", and the) may 1 larger. The pores, as mentioned, are confined to one surface of the sponge, but this is not the i with oscula\ these are found scattered on both sides, the) form almost circular openings, and the largest ones were measured to 2-5mm, these being found in the upper edge of the sponge. < >n the pore side several openings are seen, from whose sizes it cannot be decided whether the) are pores or oscula; but, generall) speaking, oscula and pores are separated b) the size. The skeleton. The dermal skeleton consists in the common way oi dermal spicules. ( )n the pore side they form bundles or short fibres reaching Mom the edge of the subdermal cavities into the membrane, and sometimes branching in between the pores. They are generally highly recumbent, often quite horizontal, and spicules are also found scattered and lying horizontally in the membrane. < >n the side that has no pores the dermal skeleton is less developed, and here horizontal spicules are especially seen scattered in the membrane, which, to a great extent, is resting on the skeleton below. The main skeleton is a quite irregular, mostly polyspicular reticulation, in which, however, also single spicules are seen. Fibres are found running chiefly in the longitudinal direction of the sponge; they may divide and unite again; they are polyspicular, but loose and little marked. Thus this species, the form of which is more marked than that of the other species, also shows a tendency towards a somewhat more differentiated skeletal structure. The fibres that are present represent primary fibre.-, while the scattered spicula-bundles and single spicules may be regarded as representing the secondary fibres. A distinct, but white and clear mass of spougin is found in the places where the spicules are united; in places it may be seen entirely to coat the fibres with a quite thin laser. The sponge fre- quently embodies sand and other bottom material. Spicula: a. Megasclcra. i. The skeletal spicules are styli; they are somewhat curved, and the curve is most frequently nearest the upper end; the point is short or rather short, sometimes a little longer; it is often distinctly marked off and bounded by straight lines. Their length is _0.--in,n aiK] (-ile thickness ca. o'Oio — o-oi3mm. Developmental forms, down to quite fine one.-, were seen singly. 2. The dermal spicules are tylota with well developed ends; they are most frequently straight and about cylindric; their length is 0-25 — 0-34mm, the thickness varies from 1 18 0*004^ While the full) developed tylota are of equal or about equal thickness 111 both end-, the singly occurring developmental forms have one end a little thinner than the other ami with a more marked swelling, b. Microsclera; these are birotulse of two sizes. 1. The large birotuhe have at eithei end a number oi from twelve to twenty teeth; their length is moo o-028mm, the thickness of the -haft is cnx)i.| --(.•(» 12""", and the breadth across the circle of teeth 1.- ca. 00057— ooog :. Vccordin; what is stated above, the numbei of teeth is rather varying, but some difference ma) be found in differ- ent individuals; thus in one specimen the number is more frequentl) neai or at the highest number, while in the two others it only rarely reaches the highest figure. 2. The small birotuhe have at either end nine to fourteen teeth; their length iso-oi2i [8mm, the thickness of the shaft is ca. o-ooo and the breadth across the circle of teeth is ca. 0-< « 1 \:\ "> " . As is seen, the two sizes oi hiiolukc approach each other \ er\ closely, and quite singl) forms are seen of a size midwa\ between the two forms. The microscleres are found as well in the dermal membrane as throughout the sponge; the small b are everywhere numerous, the large one- scarce. I [ngolf-E n|, 'liih.ii \ l I94 PORIFERA. II. Locality : The Ingolf, station i, 620 30' Lat. N., 8° 21' Long. W., depth 132 fathoms, two specimens; 620 29' Lat. N., 5 17' Long. W., depth 160 fathoms (Ad. Jensen, the cruise of the Michael Sars 1902), one specimen; 66 54' Lat. X., 150 35' Long. W., depth 58 fathoms (H. M.S. Beskytteren > Gemzoe), one specimen. The localities are situated at the Faroe Islands and north of Iceland. 8. I. affinis n. sp. PL XVIII, Fig.8a-e. The for in massive, somewhat erect? The dermal membrane a thin film, supported by bundles and short fibres of dermal spicules. The skeleton an irregular, polyspicular reticulation. Spicula: Megasclera: the skeletal spicules styli o-jy — 0-57""". the dermal spicules tylota crjj — trjj"""; microsclera two forms of birolutcr, large ones with nine to thirteen teeth crojy — o-ojj""", small ones with eleven to fifteen teeth 00i8—0-O2$mm. ( )f this species we have one highly damaged sjjecimen. To judge from this, the sponge seems to have been erect, I suppose, of about a thick, irregular cylindric form. The height is ca. 70""" and the thickness ca. 50mm. The colour (in spirit) is grayish brown. The consistency is exceedingly loose and brittle, to which the bad state of preservation may partly be owing. Of the dermal membrau, only a few fragments on the upper surface of the sponge are preserved; it is a rather thin film, showing here pores and oscula. The pores are gathered in groups; they are about circular, their size was measured to between 0-03 and o'24mm. Oscula are scattered between the pores; they are also circular, of a size of ca. o-5mm. The skeleton. The dermal skeleton is formed in the usual way by dermal spicules partly forming erect bundles, partly passing under the membrane as fibres from which spicules project. The main skeleton is a chiefly polyspicular, quite irregular reticulation; meshes are formed, but they are quite irregular; longer fibres do not seem to be formed, or are only formed to a small degree; in sections, however, a tendency is seen towards fibres passing in the longitudinal direction, but they are generally rather short. In a few places the skeleton appears to be a little more regular. A distinct, but clear and white mass of spongiu is found where the spicules are united. The sponge embodies sand and gravel to a rather high degree. The skeletal structure in this species seems, with regard to development, to occupy a position between the incrustiug or massive species and a leaf-shaped species as the polydentata described above. Spicula: a. Megasclera. 1. The skeletal spicules are styli; they are somewhat curved, not rarely a little irregularly; the curve is most frequently situated nearest to the head-end. They are only little tapering outward, and the point itself is rather short. Their length is 0-47 — 0"57""n, and the thickness is ca. O'on— croi5,T"n. A few developmental forms were seen. 2. The dermal spicules are tylota; their ends are more or less, most frequently rather slightly, swollen; the tylota are straight or quite slightly curved. Their length is 035 — o\44mm, and the thickness is ca. 0-0035- -0-0057""". There is, as usual, a little difference between the two ends of the tylota, the shaft being somewhat thinner in one end than in the other, and this feature is the more marked, the younger the spicule is. b. Microsclera ; these are birotulse of two sizes. 1. The lartre birotulse have at either end nine to PORIFERA. II. thirteen teeth, comparatively long and directed much downward, so as to form a small angle with the shaft. Their lenght is 0-037— 0-051 ",,n, the thickness of the shaft is ca ! -o-0028m,n, and the breadth across the circle of teetli is about croio o-Oi28mm. A few smaller specimens art- seen, down to a length of 0-030""". Not rarely the shaft is slightly rugged or spined, a feature that recalls the similar one in the amphidisci of the Hexactinellida. 2. The small birotulse have at either end eleven to fifteen teeth. Their length is 0-018— o-025mm, the thickness of the shaft is ca. o-OOii,nm, and the breadth across the circle of teeth ca. o-oo^j""". The small birotulse differ from those of polydentata not only by the size, but also by the fact that the thickening of the end of the shaft from which the teeth issue, is flatter and more disc-shaped in affinis than in polydentata. Both forms of microsclera occur throughout the tissue, the small ones being more numerous than the large ones; in the dermal mem- brane the large ones seem especially to occur. Locality: Cape Tobin on the eastern coast of Greenland, 70 33'LaLN., 22 00' Long. W., depth 57 fathoms, one specimen. (The Amdrup-Expedition 1900). 9. I. spinosa n. sp. PI. VI, Fig. 8. PI. XIX, Fig. 1 a-e. Erect, irregularly cylindric? The surface smooth or very slightly shaggy. The dermal membrane a tliin film, supported by erect or recumbent bundlt s oj dermal spicules. The skeleton an irregular, polyspicular reticulation. Spicula: Mcgasclcra: the skeletal spicules acanthostyli with scattered spinu- lation trjo — o-j_?""". the dermal spicules tylota 0^24 — o'jf"""; microsclera two forms of birotuhe. la ones lo/ll/ eight to twelve teeth voji — O'ojj""", small ones with nine In thirteen t<-eth o-o/S (rojj""". ( )f this species, which is especially interesting on account of its spicules, we have only a frag- ment, no doubt the upper part of the sponge. Below, from the place where it has been broken off. and some way up, the sponge is a little compressed, but then it becomes about cylindric with a rounded upper end. According to this, the form might be supposed to have been erect and more 01 less irregularly cylindric. The height of the specimen is 2jmm, and the thickness above is 8mm. The colour (in spirit) is yellowish grav. The consistency is rather brittle. The mrfacc, in undamaged places, is smooth or very sligthly shaggy. The dermal membrane is a thin film, supported 1>\ dermal spicul Pores are seen here and there on the surface in groups, the) are rather large, up to j Osctila were not seen. The skeleton. The dermal skeleton consists of erect 01 more or less recumbent bundles of dermal spicules. The main skeleton is a quite irregular, polyspicular network; tolerabh distinct fibres are formed, but they have an irregular course, some of them, however, seem to be running towards the surface. A distinct and fairh copious mass of spongin 1- found in the skeleton, in many places coating the fibres entireh with a thin layer. Spicula. a. Mcgasclera. 1. The skeletal spicules are acanthostyli with a rathei scat; spinulatiou; they are straight 01, most frequently, slightly, not rarely irregularh curved. The point is a little varying, between rather short and middh Ion-. Their length is 0-4 and the thick; ca. o-oii mii) . A few developmental forms wen seen, the finest ones are about smooth. The 196 PORIFERA. II. mal spicules are tylota with rather slightly swollen ends; they are about cylindric and straight or quite slightly curved. Their length is 0-24 — 0-34""" and the thickness ca. 0-0053 — 0-0085""". b. Micro- sclera; these are birotulse of two sizes. 1. The large birotulse have at either end eight to twelve h, their length is 0-031—0-045""", the thickness of the shaft is ca. 0-0018—0-0028""", and the breadth across the circle of teeth O'ooS — o-onmm. A few developmental forms were seen; they consist of a shall with a pyramidal swelling at either end, and on these swellings slight ribs are seen. 2. The -mall birotulse have nine to thirteen teeth at either end, their length is 0-018—0-024""", the thick- ness of the shaft is ca. o-ooi'"'", and the breadth across the circle of teeth 0-0057"'"'. Both forms -of microscleres occur throughout the sponge, the small ones are somewhat more numerous than the large ones. Locality: Station 113, 69° 31' Lat. N., 7° 06' Long. W., depth 1309 fathoms (bottom temperature -=r i C), one specimen. While the preceding species were obtained on bottom with positive tempera- ture, the present one is from the cold area. Among the hitherto described lotrochota-s^ecies I. abyssi Cart, is the only one from cold bottom, having been obtained at 61° 10' Lat. N., 2° 21' Long. W., at a depth of 345 fathoms with a bottom temperature of -=- i°i C. I have here established eight new species of the genus Iotrochota, as it has been impossible to identify any of the species before me with any of the hitherto described ones, all of which, with the exception of abyssi Cart, and magna Lambe, are also exotic species. As will have been seen from the descriptions, several of the species are chiefly separated by characters found in the microscleres, especially the number of teeth in aneorae and birotidae. Now this feature is no constant one, but varies within certain limits; therefore the numbers of teetli of the different species may pass into each other, so that, for instance, the highest number in one species may be equal to, or a little higher than, the lowest number in another species. Nevertheless I think that the number gives a good specific character, and it is in my material always supported by other characters. Unfortunately, we have only a single specimen of most of the species; perhaps a richer material may somewhat alter tin- interpretation of the species I have established here, but at present the absolutely most correct thing is to keep the species here established distinct, and I am also inclined to believe that new and richer material will prove them to be constant. The view advanced by Dendy (Proceed, of the Roy. Soc. of Victoria, VIII, 1896, 23) under the mentioning of /. coccinea Cart., that the Iotrochota- species may all be mere local varieties of Bowerbank's /. purpurea , will, no doubt, prove to be erroneous, and the author himself so far contradicts it, as in the very place mentioned he establishes a new species. To facilitate the general view of the species established or treated here, I give a table of the difference in the spiculation. PORIFERA II Megasclera Skeletal spicules Dermal spicules Microsclera varidens oxeata abyssi Cart. dubia intermedia . rotulancora polydentata affinis ipinosa . . . . styli 0-51 - 0-608 oxea 0-56 o-68 oxea and styli o-6— o-67mm 0-408- 0-49""" styli 0-46-0-536"™ most frequently slight spines at the head-end. 0-357 0-48'™ 0-40—0-55"" 0-42 o-57n,m "•47 "-57 0-40— 0-52""" spined. tylota 0-298- 0-38"' ( 1-32 0-42 1 . 198 1 »,357ni" "\\\ -0-38' 0-26- 0-34""" 11-30— 041""" 0-25—0-34 0-35-0-44""" 0-24 0-34""" ancorae .S S free teeth 0-054 o-o6 9 [3 free teeth. 0-048 "'<'<>- more than 6 teeth. 0-055—0-1 '' 1 7 9 free teeth 0*038 I- 9- 1 I IH i tritll ( 11 140 0 1 2 17 teeth 0-030- I IX^I I birotulae, large 1 2 20 teeth 1 >■< i2< 1- 1 n 128 9- [3 teeth 0-037 °'°5J S — 12 teeth 0-031- 0-045 birotulae, small 9 14 teeth 13 ca. 20 teeth 0-015 o- < tli I I I.| !. 18 1 n 12 I 14 [5 teeth I 9 12 teeth 0-018 : t teeth 0-OI28—O-OI8 II 15 teeth . i-. 1 1 8 1 1 2 5 [3 teeth [8 -0024 The ancorae occurring in species of this genus form quite evident!}' a transition to birotulae, what is seen especially distinctly in the species rotulancora. On the other hand, these ancorse are evidently allied to such forms as those found in Chondrocladia and Cladorhiza, and these forms lead again, I suppose, to the other existing forms of ancorse. Lindgreen (Zoologisch. [ahrbtich. XI, [S98, 355) says that the birotulae occuring in lotrochota must either be supposed to be only analogous to the ancorae of the other Desmacidonidse, or else to represent a more original form. 1 think the lattei supposition the more correct one. Birotulae have also in their structure so great resemblance to the amphidisci of the Hexactinellida, that it is difficult to divest one's mind of the idea of a relation between these bodies. The Zotrockota-species may show some difference with regard to the spicules. As will have been seen, the species described here are separated into two groups, those having ancorse and biro- tulae, and those having onh birotulae; the separation is of no greater systematic importance, <>n account of the transition between ancorse and birotulae. Also with regard to the megascleres some difference may be found. The skeletal spicules are typically smooth styli; they may be spim nosa), sometimes they may be rounded at the pointed end fbirolulala). further the) ma; ' (oxeata), and finally the) ma) be a mixture of styli and oxea (abyssi, acerata). The dermal spicules are typically tylota, but may be monactinal (purpurea, birotulata, magna, coccinca); this fact, however, is of no real importance, as the dermal spicules are upon the whole onh secondarily diactinal. rg8 PORIFKRA. II. As far as I know, the following lotrochota-species have hitherto been described : Fotrochota (Halichondria) abyssi Cart. . . (Between the Faroe Islands and Scotland! — (Halichondria) purpurea Bow (Australia, Strait of Malacca) - (Halichondria) birotulata Higg (Jamaica - bacculifera Ridley (Australia, Amboina, Cochin China, Seychelles, Mascarene Isles, Madras) - (Phlceodictyon) birotulifera Cart (South-Australia — (Axinella) coccinea Cart (South-Australia — magna Lambe [Northern west-coast of America) — acerata Dendy (Australia i Megaselera Mieroselera Skeletal spicules Dermal spicules Styli and oxea Styli Styli to strongyla Styli Tylota Styli Styli Tvlota Ancorae and birotulaj Birotula; Birotuht- Birotulse Two forms of tylota Birotula; (The place of the species is doubtful1)). Styli Styli Birotula Styli Styli and oxea Styli Tvlota Birotula; Birotula; Forcepia Cart. The exterior varying, as a tliick incrustation or thicker and more massive, or erect and formed as a thick, more or less irregular leaf. The skeleton a mostly polyspicular reticulation, in the incrusfiug or massive forms quite irregular, in the erect ones more differentiated with more or less distinct primary longitudinal fibres, between which transverse spicules most frequently single, irregularly placed. The dermal skeleton consisting of erect or recumbent bundles of dermal spicules, sometimes, moreover, scat- tered horizontal spicules. More or less sfongiu present. Spicula : Megaselera : the skeletal spicules smooth or spined styli, the dermal spicules tvlota. sometimes strongyla : mieroselera : the characteristic mieroselera art spined forcipes of one or two sizes, to which a/most always are added isochelce arcuata> of one or two sizes and often sigmata. i. F. forcipis How. PI. XIX, Fig. 2 a— h. 1866. Halichondria /orcifis Bowerbank, Mon. Brit. Spong. II, 244, n. 1S74. Boverbank, ibid, III, 105, PI. XLIII, figs. 7—13. [874. Carter, Ann. Mag. Nat. Hist. Ser. 4, XIV, 246, PL XIV, figs. 29— 32, PI. XV, fig. 41 a — b. i8/ two sizes, largt ones 044 032""", small < 0-028— 0-036""". Of this species we have only one, highly damaged specimen, growing as a thick incrustation on the carapace oi a Ilyas coarcialus, and a quite insignificant fragment. The specimen has a great- est extent of 36""" and a greatest thickness of 5""". The specimens described In- Bowerbank and Carter were of a similar form, hut a little larger, having a greatest extent of respectively ca. 80 and 45""", and Carter's specimen having a thickness of fully 121"". The colour (in spirit) is gray. The consistency is rather firm, but somewhat brittle and little elastic. The surfact is slightly grooved, the skeleton below causing small protuberances; otherwise it seems to be smooth. The derma/ mem- brane is a thin, transparent film, supported by bundles of dermal spicules. Pores were m it seen on my specimen. A few circular openings in the membrane I take to be oscula. Carter describes the surface and the dermal membrane in the same way, but his specimen showed also the pores gathered in sieves over the subdermal cavities. Also Bowerbank mentions pores gathered into a group. The skeleton. The dermal skeleton consists of bundles of dermal spicules, issuing from the skeleton below and supporting the dermal membrane; they are, however, very little projecting, but highly, almost horizontally, recumbent; also scattered spicules are found here and there in the mem- brane. The main skeleton is a polyspicular, but quite irregular network; meshes are formed, but they have no definite form, and longer fibres are not formed. Here and there in the network single spi- cules are found, but otherwise it is polyspicular. The number of spicules alongside may vary rathei much, most frequently it seems to be four to five, but it may also be greater, up to about ten. Spongin is found in the nodes of the skeleton, but it is very white and clear. Spicula: a. Megasclera. 1. The skeletal spicules are styli; they are evenly and slightly curved, the curve being most frequently found nearest to the rounded end; they are of about equal thickness troughout the length, and the point is rather short, it is most frequently distinctly limited and bounded by straight or almost straight lines. Their length is between 0-488 and 062 , rarely at the lower limit. The thickness is from ca. 0-0128— o-02imm. Developmental forms at different stages, down to exceedingly line ones, occurred rather frequently; tlu- finest ones were long pointed. One of the finest forms was o-47""" long. 2. The dermal spicules are tylota with slightly swollen ends; sometimes the ends are so little developed, that the spicules approach strongyla; they are cylindric and most frequently straight. Their length is 0-238 0-309 . and the thickness is ca. 0004 - In the fully developed spicule the two ends are about equal, the shaft being at most a little thinnei in one end, and the swelling therefore a little more 111. irked; the younger and finer the spicules are, the greatei is the difference between the ends, and tin finest developmental forms seemed to have one end pointed. Then the developmental forms show the peculiarity of being almost always poly- tylote with a series of swellings along the shaft, which swellings dissappeai by degrees, as the spicule grows thicker, b. Microsclera; these are oi foui forms, two forms of isochelse arcuatce, large and 200 PORIFERA. II. small ones, and two forms of forcipes, also large and small ones. i. The large chelae have an evenly, but slightly curved shaft, the tooth is narrowly elliptical with a longish tubercuhun, from which a continuation may be traced about to the end of the tooth; the alse are of the same length as the tooth and are somewhat tooth-like, when viewed from the side. Their length varies from 0-043— o'o67n""> most frequently it is midway between these sizes; the thickness of the shaft is 0-004 — o-oo7n,m. A few monstrosities with split tooth were seen. 2. The small cheke are of a similar form, the only difference being that the tooth and the ake are comparatively longer, and the tooth is broader; their length is 0-021 — o-028mn\ and the thickness of the shaft is 0-0014 — o-oo2imm. Develop- mental forms were found of both chela; at different stages, but only sparingly. Quite singly chelae were seen occupying, as to size, a middle place between the two forms. 3. The large forcipes are peculiar and beautiful spicules. They have a round curve above, and continue in two very long, more or less parallel, legs, one of which is always a little longer than the other; the legs may be a little diverging or converging, but always only to a slight degree; when converging the)- often touch each other. The forcipes are most frequently a little twisted, so that the legs intercross. They are spined, and the spines are all turned upwards towards the curve, and formed in such a way, that the legs may more properly be called serrated. The spines are almost exclusively found on the in- and outward turned sides of the legs only, that is to say, in the plane which includes both legs; they are generally more close-standing on the inward side of the leg than on the outward side, and on the inward side they are especiallv close-standing in the middle part of the leg. At the curve the spinu- lation becomes more rugged, and here some spines may be found all round. The length, measured from the curve to the point of the longer leg, is 0-44— o-52mm, the thickness at the curve is 0-0058""" and about the middle of the legs it is o-oo28mm. An interesting thing it was to find the develop- mental forms of this spicule, and thev are not especially rare; thev are of the same, or about the same, length as the fully developed spicule, but they are finer, down to very fine; then they are quite smooth, only the more developed stages begin to get at little rugged in the upper part. 4. The small forcipes are of a peculiar form, one leg being more than three times the length of the other; the short leg is straight, while the long one with an arcuate curve bends towards the side where the short leg is found. The legs end in a little knob. When seen under slight magnifying powers these forcipes look as if they were rugged, but when the magnifying powers are higher, they are seen to lie spined, and the spines are arranged in the same way as in the large forcipes. This spinulation and the terminal knobs of the legs, especially that of the long leg, are, however, only to be seen with great difficult)'. Their length is 0-028 — o-036mm; they are exceedingly fine, the thickness at the curve not being more than 0-0007'"'". This small spicule is easily overlooked; it is Carter's merit first to have seen it, but according to his erroneous view of the growth of the spicules he called it embryonic form of the large forceps; neither has he been able to see their form eorrectlv, nor their spines. The microscleres are found through the whole sponge and in the dermal membrane, wdiere the large chela seems to be most frequent. The large forcipes occur in the tissue in bundles that may almost form fibres; the single forcipes in the bundles seem all to be turned one way. Locality: Station 78, 6oc 37' Lat. N., 270 52' Long. W., depth 799 fathoms, a very small fragment the Faroe Islands, east of Sudero, depth ca. 150 fathoms, one specimen (Th. Mortensen). PORIFERA. II. O Geogr. distr. The Shetland Islands (Bowerbank), between Scotland and the Faroe Islands, depth 363 fathoms (the Porcupine ). Tims the species is only known from a rather limited territory. Strange to tell, the bottom temperature of the localit) at which the Porcupine has obtained the species is given to -f oc3 C, while the species i- otherwise onl) known from localities with positive bottom temperatures. Remarks: As I have examined a specimen sent by the Rev. .Mr. X or man, the identification f this species, which is otherwise a very characteristic one, is sure. Norman's specimen shov sigmata, neither were such found by Carter in his specimen. It is an obvious conclusion that the bodies which Bowerbank has supposed to be sigmata, have been developmental forms of the small chela. 2. F. fabricans ( >. Schmidt. PI. XIX, Fig. 3 a g. 1S74. Esperia fabricans O.Schmidt, Die zweite deutsche Nordpolarfahrt, II. 2, 433. 1885. Forcipina bulbosa Vosmaer (Synon. except), Bijdrag tot de Dierk., iate Afl., 3die Gedeelt, PI. I, fig. 11, PI. V, figs. 60— 68. 1903. Hamigera (Forcipina) fabricans Thiele, Arch, fur Naturgesch., 1903, I, 385, Tat. XXI, Fig. 15 a — e. Massive, sometimes somewhat erect. The surface slightly shaggy. The dermal membrane a thin film . supported by projecting bundles of dermal spicules. The upper surfdci oj the sponge set . papilla:, in the points of which oscula open. The skeleton a rather irregular network ~ ' ; 1 5 "n, and the thickness is 0-0128 — o'02imm. Some developmental forms were seen, the youngest ones are long pointed. 2. The dermal spicules are tylota; they are straight, and their ends are most frequently rather slightly swollen. Their length is 0-31— o-45'nm, and the thickness 0-007— o-oi2mm. The shaft is a little thicker in one end than in the other, and the swelling of this thicker end is most frequently so slight, that the spicule might be called a tylostrongyle ; the swelling of the thinner end, PORJFERA. II. 2Q-, on tlie other hand, is larger and more distinctly marked. The younger the tylotes are, the m marked this difference is. The .shaft of the tylotes often shows slight, irregular thickenings, so that they may approach polytylota. b. Microsclcra; these are of lom forms, isochelse arcuatse, forcipes oi two sizes, and sigmata. i. The arcuate chelse have an even and not much curved shaft; the tooth is narrowly elliptical, and there is a longish, pointed tuberculum; the alas are tooth-like and oi about the same length as the tooth. The chela may be of a somewhat varying form, the tooth and especially may be shorter or longer in proportion to the total length. The length is 0*042 the thickness of the shaft is 0-0042 — o-oo57mi". A few developmental forms were seen. 2. The large forcipes are of a form quite like that figured by Vosmaer I.e. They have a round curve aboveand two parallel, or quite slightly converging or diverging legs; only rarely the legs are more diverging. The legs are of equal length, or there may be a quite slight difference in this respect; they end ii little swelling. The forcipes are spined; under small magnifying powers the spinulation looks some- what rugged, hut by sufficient enlargement (ca. x 1000) it is seen to consist oi well developed spines directed backward and somewhat compressed ; they are, moreover, rathei distinctly arranged in row- By this enlargement the swelling at the end of the legs is seen to be a semiglobular knob attached to the leg by the flat side; this knob is somewhat spined or indented in the t-d^'j. The forcipes are frequently a little twisted. Their length is o-o6o — O'OJJ""", and the thickness in the middle of the legs is ca. 0-0029™"'. Of forcipes a few developmental forms were found, the finest ones are quite smooth, and the ends of the legs are finely tapering without any swelling. 3. The small forcipes have a quite similar form as the large ones, only they are much smaller, and the difference between the lengths of the legs is most frequently a little more marked; the\ are also spined. quite in the same way as the large forcipes. Their length is 0-025— 0-034""", aU(' tne thickness in the middle of the legs is about o-ooim'". 4. Sigmata; these are rather large, they are of the common sigma-form, and are plane or a little contort. Their length is rather constant, o-i2— 0"i4mm, ami the thickness j- 0*0 o-oojmm. < )f t]ie sigma a rather great number of developmental forms were seen, the youngest stages were verv fine and had as yet no recurved ends. The microscleres are found through the whole sponge, as well in the skin as in the other parts of the bod) ; in the membrane coating the bottom of the pore grooves, the chelse are found very abundantly, but none oi the other forms. Note. In the skin cellules spheruleuses are found in great abundance; thev appear as 1 or less distinctly limited crowdings of refracting granules; often the boundaries of the cells are effai so that the dermal membrane appears closeh filled with refracting granules more 01 less gathi in groups. Embryos. Round in the tissue souk embryos were found scattered. The) are globular, ol average size of o-^s"1'"- Most of the examined specimens showed no spicules, some exception- \. however, found. These latter had microsclera, but onl) chelae, which is thus the first occurring form; they occurred abundantly at all stages of development, from line staves to almost quite develo] spicules. They are smaller than the cliche of the developed sponge, being from 0 ' long. Remarks: From Schmidt's description cited above, this species would not be recognisabl all, and the two figured cliche do not even belong to it. Thiele, however, lias examined the type specimen, and from his description and figures I have been able t«> identif) the species with certainty, although _,,,( PORIFERA. II. Thiele has not seen the small forcipes or has paid no attention to them. With regard to Thiele's referring of the species to Hamigera see p. 211. Also Vosmaer's description and figures, as well of the exterior as of the spicules, agree in all details with my specimens. The spicnle figured by Vos- maer fig. 66 is a developmental form of a forceps; he has overlooked the small forcipes. The species cited by Vosmaer under the synonym}-, do not belong here, F. forcipis being a quite distinct species, which holds good also of F. bulbosa Cart. The F.bulbosa mentioned by Tops en t (Resultats des Camp. scient dti Prince de Monaco, Fasc. XXV, 179, PI. I, fig. 13) is not Carter's species, but a new, inde- pendent one, and when Topsent mentions Vosmaer's species under it, it is a mistake, as it is not identical with this species either, but differs as well by its spiculation as by the want of the papillae characteristic of F. fabricans (= bulbosa Vosm.). The present species is a native of the cold bottom, while as well Carter's species as that of Topsent are natives of the warm bottom, respectively from Cape S.Vincent and the Azores. For further particulars see under the account of the species of the genus p. 210. Locality: 620 30' Lat. N. , i° 56' Long. E. , depth 275 fathoms (bottom temperature -f- cri2 C.) (Ad. Jensen, the cruise of the Michael Sars» 1902); East-Greenland, Forsblad's Fjord, depth 50 — 96 fathoms (the Amdrup-Expedition); East-Greenland, without any more particular statement (the East- Greenland Expedition 1891 — 92). Geogr. distr. The species has been taken before at East-Greenland, North Shannon (zweite deutsche Nordpolarfahrt, Thiele 1. a), and by the Willem Parent-Expedition off North Cape, 720 36' I. at. N., 240 75' Long. E., depth 140 fathoms. To judge from the localities it is probable that the species is a native of the cold bottom. 3. F. Topsentii n. sp. PI. VII, Fig. 3. PI. XIX, Fig.4a-g. Massive, cushion-shaped. The surface set with conical papillce, ami slightly shaggy. The dermal membrane a thin film with horizontal dermal spicules and here and there erect bundles. Oscula open into the papilltc of the surface. The skeleton an irregular reticulation, partly polyspicu/ar, partly uui- sfieitlar. Spicula: Megasclera: the skeletal spicules styli 0-62 — o-jp'"". the dermal spicules strougyla to tylota fjj/ — 0-45"""; microsclera of four forms, isochelic arcuatu- vojj — cra/7""", forcipes of two sizes, large ones ■ mp"'" . small ones 0-022 — 0-035""", sigmata. plane or almost plane, 0'i2 — cyip"1". Of this species we have one large specimen and some quite small ones. The species is formed like a cushion. The large specimen is torn off from its substratum, which, to judge from the form of the surface of attachment, may have been a shell; the small specimens are attached to bottom material of various kinds, foraminifera, gravel, etc. The sponge is set with rather close-standing, conical, pointed papillae of an average length of ca. 4mm. The papillae are numerous in the large specimen, while in the small ones only some few papillae are found. The largest specimen is somewhat longish, it has a length of 6o,n'", a greatest breadth of ca. 45'"'", and a height of fully 20mm. The small specimens are dently quite young ones, they are 5 — 6:nm long. The consistency is only little elastic, on the con- trary, it is rather hard, almost cartilaginous. The colour (in spirit) of the surface is brown, the PORIFERA. II papillae are whitish, the inside of the sponge is grayish white or quite white. The surfact is slightly and dispersedly shaggy. The dermal membrane is a rather thin, easily separable Kim, resting on the skeleton below and provided with horizontal dermal spicules. Oscula: the papillae described above are oscular papillae; some of them are closed, others show a little opening at the apex of the cone. If a papilla is cut off, a canal appears under it passing more or less perpendicularly into the sponge, which is consequently set through with a number of more or less perpendicular canals. Pores were not seen. The skeleton. The dermal skeleton consists of dermal spicules, which are mostly horizontal and irregularly scattered in the membrane; the membrane seems to be resting on the main skeleton below, the spicules of which may project here and there. The dermal spicules, however, form also, lure and there, bundles passing from the skeleton below and supporting the membrane. In the walls of the oscular papillae the dermal spicules are close-lying, all of them parallel to the longitudinal axis, and thus forming a close spiculation in the wall. When the papilla is contracted and closed, the spicules form a compact mass. The main skeleton is a quite irregular, partly polyspicular, partly unispicular reticulation. Meshes are formed, but they are quite irregular. Fibres an- only seen to a quite slight degree, and, when found, they are only short and little marked. The spicules are united by a slight amount of white and clear spongin. Spicula: a. Megasclera. i. The skeletal spicules are styli; they are somewhat curved, the curve is sometimes situated at the upper end, but sometimes thev are more evenly curved, and they may also be somewhat irregularly curved. They are in some degree fusiform, tapering distinctly towards the upper end. The point is even and middle long. Their length is o-62 074""", and the thickness in the middle is cro2i — ooaS1""'. Developmental forms occurred quite singly. 2. The dermal spicules may most properly be called strongyla, but most frequently they have end-swellings so as to approach tvlota; thev are somewhat fusiform. Their length is 0357— 0-45,llnl, and the thickness < ><:>i 14 — o'oi5'"m; sometimes they show a tendency to the polytylote form. In the fully developed spicule the ends are equal; only few developmental forms were seen, showing that the spicules are begun as monactinal. b. Micros clera ; these are of four forms, isochelae arcuatse, forcipes of two forms and sizes, and sigmata. 1. The chelae arcuatse resemble the chelae in the preceding species, F. fabricans; they have an evenly, sometimes rather highly curved shaft; the tooth is narrow, lanceo- late, and has a short tuberculum, the alae are somewhat tooth-like and of about the same length as the tooth. Their length is 0-034 -cma;""", and the thickness of the shaft is ca. 0-004 0-0057""". J. The large forcipes have two legs of equal length, ending in a small, button-like swelling; the curve max be varying, it may be so strong, that tin- legs are parallel, and then it may be more and more slight, until the legs form an obtuse angle; the forcipes are spined, and the spines are compressed and di- rected backward. No serial arrangement of the spines is found lure; the terminal knobs of the legs are, as in /•". tain-nuns, indented or spined at the edge. Their leugth, measured from the curve and to the end of one of the legs, is 0"o86 0-104 , and the thickness at the curve is 0-007 -^ lew developmental forms were seen; they are smooth, and the legs do not cud in a swelling; the) reach a comparatively considerable thickness, (>|""" at the curve, before the) begin to get spines. 3. The small forcipes have about parallel legs, one of which is almost always somewhat longei than the other; the legs end in a small, button-like swelling. These forcipes are spined in the same 2Q5 PORIFERA. II. way as the large ones; sometimes they are somewhat twisted. Their length is 0-022— o-035mm, and the thickness at the curve is about crooi""". Unite few specimens of forcipes are seen, forming, as to size, a transition between the two forms. 4. Sigmata; they are of the common sigma-form, and are plane oi onlj very little contort; their length is 0-12— o-i4mm, and the thickness 0-007 — o-ooSmm. The micro- scleres occur throughout the sponge and copiously in the dermal membrane; in the points of the oscular papillae the chelae are found abundantly. This interesting species is a distinct one, and is well distinguished from the other Forccpia- species. The form of the large forcipes might lead one to think of F. bulbosa Cart., but there is, in other respects, great difference between these two species, thus with regard to the sizes of all the spicules and especially of the forcipes and sigmata, and also with regard to the form of several of the spicules; finally Carter's species is from Cape San Vincent, whereas the present species is a native of the cold bottom. Locality: Station 113, 690 31' Lat N., f 06' Long. W., depth 1309 fathoms (bottom temperature -f ioC-l, six very small specimens; station 119, 670 53' Lat. N., io° 19' Long. W., depth 1010 fathoms (bottom temperature -r- 11 C), one specimen. Thus the species is a native of deep water and of the cold ana. The two stations are situated between Jan Mayen and Iceland. 4. F. Thielei n. sp. PI. VII, Figs. 1—2. PI. XIX, Fig. 5 a— f. Erect, formed like an irregular, thick leaf, attached below. One surface oscular surface, the nl Iter pore surface. The oscular surface even with rather close-standing oscula, the fore surface with more or less deep grooves separated fry sinuous walls; the surface slightly shaggy. The dermal mem- brane a thin film, supported fry bundles of dermal spicules. The skeleton a rather irregular, polyspicitlar network; primary fires are found, bending towards the surface, but irregular, between them close-set, single spicules. Spicula: Megasclera: the skeletal spicules styli o-$y — cryj""". the dermal spicules tylota ir ;_f -tj-jo"""; microsclera of three forms, isochelee arcuahe 0-021 — o-ojj""", forcipes n-oj/ — ao6u""". sigmata, plane or about plane, iru — aij" -,m»i This species is formed as an erect, thick, somewhat irregular leaf. Below it is expanded and attached with a thick, lumpy base. The species seems to have grown directly on the bottom, a great deal of .gravel and other bottom material being found in the basal surface, and bottom material being also embodied in all the lower part of the sponge. Most of the specimens in hand are only fragments, only one of them is about entire; this latter specimen has a height of i8omm, a breadth of 120""", and a thickness of ca. 25mm, farther down towards the base the thickness is about 50"™. The fragments seem upon the whole to have belonged to specimens of similar dimensions. The consistency is rather firm, but little elastic and somewhat brittle. The colour (in spirit) is grayish white or whitish yellow to light brown. The surface is different on the two sides of the sponge, of which one is the oscular side, the other the pore side. The oscular surface is tolerably even; when oscula are shut, however, the entrance to them are seen as rather deep, circular grooves. The pore surface, on the other hand, is PORIFERA. II. most frequently closely grooved, and the- grooves arc separated by curling or meandering walls. Some- times the walls run chiefly in the longitudinal direction of the sponge, and the surface may get an appearance, as if longitudinal fibres were running below it. Sometimes the pore surface is fairly even, the walls not being raised; this, I suppose, is owing to the degree of contraction of the sponge. The surface is otherwise finely shaggy from projecting spicules. The dermal membrane is a rather thin film, supported by dermal spicules. Oscula and pores: As mentioned above, one surface is the oscular surface, the other the pore surface. < >n the oscular side rather close-set, circular openings of various sizes are seen. When the dermal membrane is removed, oscular canals arc seen, of an average width of 3:"'"; this size, therefore, is the largest one attained by the oscula, but they are seen in all degrees of closing. When they are closed or almost closed, the closing membrane is generally somewhat sunk into the canal, so that a more or less deep, about circular groove is seen. From the oscular apertures canals pass into the sponge, partly tolerably horizontally through the leaf, parti) also running in other directions. In the upper part of the sponge they may often be seen rather distinctly to run downward and inward in the leaf. < hi the pore side the pores arc found in groups over the subdermal cavities or the openings of the incurrent canals; they were measured from quite small ones up to a diametei of 0'12;m". The skeleton. The dermal skeleton consists of penicillate bundles of dermal spicules supporting the dermal membrane. The bundles are partly erect, partly more or less recumbent. On the pore side especially, erect bundles are found in the tissue or the walls between the canals or the subdermal avities; from the edges of these cavities fibres of dermal spicules pass under the membrane distended er the mouth, and these fibres are then more or less horizontal, but send off spicules into the membrane; by this arrangement the structure arises again here which has been mentioned repeatedly in other species, viz. that the membrane or pore sieve distended over the mouths of the canals, is by the mentioned fibres divided in areas, in which the pores are then lying. On the oscular side the structure is about the same; short fibres of dermal spicules likewise stretch from the edge oi the oscular canal, radiating into the membrane and pointing towards the oscular aperture. The main skeleton is a mostly polyspicular network, which is, however, rather irregular. Longitudinal fibres are found, passing up through the leaf and bending towards the surface, but their course is somewhat irre- gular. The spicules placed between them are mostly single. They arc placed rather closely and quite irregularly, so that the meshes are irregular, by which means the whole network gets a very irregular appearance. Sometimes the longitudinal fibres ma) be seen especially distinctly to bend towards the oscular side, which is, perhaps, owing to the fact that they parth follow the course of the canals. Sometimes, on the other hand, the skeleton is far more irregular, so that longitudinal fibres arc almost not to be traced. In the nodes of the skeleton a rather copious, hut white and clear mass ol sponghl is found. Spicula: a. Megasclcra. i. The skeletal spicules arc styli; the) arc slightly curved, some- times through their whole length, but most frequently the curve is nearest to the head-end; m rarely the spicules are straight. The point is rather short or middle long, it is sharp and oftenest bounded by straight lines. Their length is 0-57 1 and the thickness is o-oi . most frequently the longest ones an- not the thickest ones. Developmental forms occurred singly; the finei c OV PORIFERA. II. ones had a longer point. 2. The dermal spicules are tylota with rather slightly swollen ends; they are oftenest straight, more rarely a little curved. Their length is 0-34 — o-40mm, and the thickness ca. 0-0043— o-ooN6mm. The fully developed spicules have almost equal ends; the swelling of one end, however, is most frequently a little more marked than that of the other; the finer the spicule is, the more distinct is this feature, and the very finest ones are quite monactinal. b. Microsclera; these are of three forms, isochelae arcuatse, forcipes, and sigmata. 1. Chelae arcuatse are of a similar structure as in the preceding species, F. Topsentii, but they are smaller; they have an evenly curved shaft, a more or less broad oval tooth with a triangular tuberculum, and the alse are of the same length as the tooth. Their length is o-02i — 0'033mm, and the thickness of the shaft is ca. o-oo2i — o-oo28mm. 2. For- cipes; these are of only one form, and they are rather characteristic; the}- have a round curve above, ami one leg is considerably longer than the other; the legs are slightly diverging in their upper part, then the shorter leg bends a little more outward, and the longer leg does the same, but this latter bends again inward, so that it forms an even, slight curve with the convexity turned outward. This is the typical form (PI. XIX, Fig. 5 d), but various deviations may be found. Thus they may be some- what twisted, and the legs may be of equal, or about equal, length, and in this case they are often more or less uniform, both forming a curve. By slight enlargement the forcipes appear to be slightly spined, but under higher magnifying powers they are seen to be rather finely, but densely spined; the legs end in a button-shaped swelling. Their length, measured from the curve to the end of the longer leg, is 0-037— o-o6omm, and the thickness at the curve is ca. 0-0014— ooo28mm. A few, quite fine and smooth developmental forms were seen. 3. Sigmata are of the common sigmaform and are plane or almost plane; they vary in length from o-n— o-i3mm, and in thickness from 0-0057— 0'007,n",. A few fine developmental forms were found , not yet provided with recurved hooks. The micro- scleres occur throughout the sponge and in the dermal membrane; in the pore sieves cheke seem especially to be found. Note. In the dermal membrane and in the membranes of the canals granulous cells, cellules spheruleuses , are found abundantly. They are roundish or longish, of an average size of o-oi5'nm, and filled with rather large, refracting granules, in spirit their colour is white. Frequently the walls of the cells have disappeared, so that the membrane is seen to be filled with granules, more or less gath- ered in groups. Embryos. In some of the specimens embryos were found in great numbers in the tissue. They are globular, of a white colour, and their average diameter is o-23mm. Some of the examined specimens showed -no spicules, others had spicules, and then both megascleres and microscleres were found. The megascleres are somewhat interesting; they are slightly curved, somewhat club-shaped styli, sometimes with a slightly marked head; they attain a length of up to o-i2mm The most interesting feature is, however, that they are slightly rugged -spined; as Forcepta-species with spined spicules exist, one is led to suppose that the spinulation may possibly be a primary character, and that species with spined spicules may be more primitive than those with smooth spicules. A fact leading to the same conclusion has been mentioned under some of the species treated above; thus M. pedunculated has smooth styli, but its embryos have spined styli, and M. pluridentata has smooth styli, but the fine developmental forms are slightly rugged. - - The microscleres are only chelae, they are of the same PORIFERA. II. 20Q structure as the chela; of the grown sponge, but reach at most a length of 0-025" :". Tlie specin in question were obtained in the beginning of June. Locality: Station 57, 630 37' Lat N., 13° 02' Long. W., depth 350 fathoms ; station 73, 62 58' Lat. N., 230 28' Long. W., depth 486 fathoms. Both stations arc situated south of Iceland. F. groenlandica Frstdt PL XX, Fig. 3 a-e. 1887. Forcepia groenlandica Fristedt, Vega Exp. vetensk. Iakttag. IV, 452, PI. 25, figs. \o -46. 1904. ? Trachyforcepia groenlandica Topsent, Resultats des camp, scient. du Prince de Monaco Fasc XXV, 181, PL XV, fig. 14. Thickly incrusting or massive. Spicula: Megasclera: the skeletal spicules acanthostyli o- 0'55mm> t!ie dermal spicules ty lota 0-40— 0-447"'"'; microsclera 0/ three forms, isochelce arc,: 25— 0-035""", forcipes 0-035— o-o^2p""", sigmata, more or less contort, 0-114—0-15 This species has not been obtained by the Ingolf-Expedition , and I have only before me a small fragment of the type specimen; therefore I only mention the spicules more particularly, a. M sclera. 1. The skeletal spicules are acanthostyli; they are slightly curved, either evenly through their whole length, or with the curve nearer to the upper end. The point is rather short, at most middle long. The spinulation is rather scattered, but in this feature some variation may be found; the spines continue out on the very point; at the head-end they are generally more closely gathered. The length of the acanthostyli is 042— o-55mm, and the thickness o-oi 1—0-014""". 2. The dermal spicules are slender, straight tylota with slightly swollen ends; their length is 040— o447:" % the thickness is ca. 0-007""". b. Microsclera; these are of three forms, isochelae arcuatse, forcipes, and sig- mata. 1. Cheke arcuatce are of a similar form as in the preceding species, F. 7 their length is 0-025— 0-035""" by a thickness of the shaft of 0-0028 — o-oo4mm. 2. Forcipes are of a form remind much of the forcipes in F. Tine lei; the shorter leg, however, is generally straight, and the Ion. forms a more curved bow; they are finely spined but not so densely as in F. Thielci, and the end in a little button. Their length to the end of the longer leg is 0-035 — 0-0529""", and the thick: in the curve is ca. 0-0014 — 0-0021""". 3. Sigmata are of the common form, and are more 01 tort; their length is 0-114 — 0-15""", and the thickness ca. 0-005 — °'°°7 Locality: The species was taken by the Sophie-Expedition £883, at East-Greenland, depth fathoms. Topsent mentions it from the sea at the Azores at a depth of r.196 fathoms. Note. This species seems to be closely allied to /•'. Thielei; like this it has onl\ forcipes, and the forcipes of the two species resemble each other and are "1 a characteristic form. It is doubtful whether the F. groenlandica mentioned by Topsent is identical with the present as its styli are very slightly spined and often smooth, and both styli and tylot; as also its sigmata are plane. Also Topsent' s species must 1 Hied to /'■'. 7 ally the sizes of the spicules are lather equal, but in . found on the styli; iugly there is some possibility that Topsent's species is an independent one. Topsent establis 'riie Ingolf-E xpedition. VI. -• 2IO PORIFERA. II. on it the genus Trachyforcepia; he establishes it with some hesitation, and I cannot, in the spinulation he styli, find sufficient reason for the formation of a genus, so much the less, as transitions are always found, and this is also here the case. The genus Forccpia is a well characterized genus, and now it contains a rather great number of distinct species. As in several other places among the sponges, the authors have not originally had an eye for the characteristic specific differences, and have regarded the occurrence of forcipes, even if they were somewhat different, as a sign of specific identity. Carter and Vosmaer, therefore, have blended different species. As mentioned under F. fabricans, the F. bulbosa Cart, mentioned by Top- sent, is not Carter's species, but a new one, what is seen distinctly from the spiculation, which is as follows: F. bulbosa Cart. F. bulbosa Tops. Styli 0-56" 071" Tylota 0-308""" 0-36-0-415" Chelae 0-038" 0-033" Forcipes 0-038mm 0-037—0-057" Sigmata o-o67"'m O'll — 0-I2mm Further Topsent's species has sometimes some spines on the styli, and forcipes seem to be of two or three forms. I propose for Topsent's species the name of F.azorica. Thus the result will be that Carter's species F. bulbosa keeps its name, Vosmaer's F. bulbosa is identical with F. fabricans Schmidt, and Topsent's F. bulbosa gets the name F. azorica. According to this, the genus Forcepia contains at present the following species: 1866. Forcepia (Halichondria) for cipis Bow. 1874. — (Espcria) fabricans O. Schmidt. 1876. {Halichondria) bulbosa Cart. 1885. — crassanchorata Cart. 1887. groenlandica Frstdt. 1895. Cartcri Dendy. (This species occupies a special place, as, according to the description, it does not seem to have skeletal spicules, but only dermal spicules. The main skeleton is chiefly composed of sand.) 1904. ' — imperfecta Tops. — Topsenlii n. sp. — Thielei n. sp. — azorica nom. n. (= bulbosa Tops. 1. c. 1904, nee Carter). It is still to be added that Carter in 1874 (Ann. Mag. Nat. Hist. Ser. 4, XIV, 248, PI. XV, fig. 47) has established a species, F. colonensis. At the time of the establishing only the forceps was known, which had been found isolated; it was very large, o-26mm. In 1885 he (ibid. Ser. 5, XV, no. PI. IV, fig. 2 a — e) refers a species to this one, the forcipes of which are of a similar form, but only PORIFERA. II. 2II attain a length of 0-093 """; according to the description the meg! of this latter sp only one kind, viz. tylota. In 1895 the species is again mentioned by Dendy (Proceed. Roy. Victoria VIII, 24), who says of the examined specimens that their forcipes are somewhat smaller than those of the type; I suppose that by the type he means the isolated forcipes upon which the spe was originally established. The question must, according to this, be of two different species, bul to the former, the one with the large forcipes, nothing definite can be said, as only the torci] known, but I think there is some reason to suppose that it is a Fori and with regard to the latter, which has of megasclera only tylota, it is at present doubtful whether it belongs to Finally it is to be remembered that the F. \ Trachyforcepia numerated by T sent I.e. is perhaps an independent species. As to Forcepia versatilis Tops, see under the genus Asbestopluma p. 75. Thiele (Arch, fur Naturgeseh. 1903, I, 3S4) says that Carter's generic name can as one of the species, by Carter referred to Forcepia colonensis, oi' megasclera has onlv tylota; I think, however, that Carter's name is to be kept, as his original type, to judge from what is stated above, may be supposed to be a Forccpia-species. — When Thiele, in the place quoted, will i Forcepia to Hamigera, and at most regard it as a subgenus under this genus, this is surely ern . or further particulars regarding this fact see under Lissodendoryx stipitata p. 173. Melonanchora Carter. The form thickly incrusting or massive, somelivu what lobar,-. The surface closely set wart-shaped papillce. The skeleton chiefly polyspictilar, bat rather h vards the surface , and between them irr* indies. The dei skeleton consists of very close-lying, horizontal spicules and 0 membrane. . amount of spongin is found in the skeleton. Spicula: the m \ and the skeletal spicules are styli, the etc nun I spicules tylota to stroi: 'arm, and then are tylota to strongyla; microsclera: the characteristic microsclera are spharan fully developed, of two elliptical rings, intersecting each other at a right angle; to these arc addca spatiiliferu- of two sizes. 1. M. elliptica Carter. PI. VII, Figs. 4— 6. PI. XX. Fig. ia 0. 1874. Melonanchora elliptica Carter, Ann. Mag. Nat. Hist., Ser.4, XIV 216, PI. XIII, figs. 6— 12, Pl.XV, fig- 35 a~b- '1 The characteristic, melon-shaped ancora was by Carter called melon-shaped anchorate : V it mel. . but an established term did not exist. Therefore it was a very natu a fixed name to this form, and he chose spherancister , finding in the individual arc to the diancistra in Hatnacantha. The chosen term, bowi ver) unfortunate, rae have nothii it all with diancistra, but are real ano md this fact oughl to be 1 n the name. The most simple tiling v therefore, to designate this form as melonancoi this nami that it is the same as thai of the genus, and sn it may give rise to confusion. 1 therefore choo 1 ignate tin phserancora;, a term showing by its ending that the question is of real ancorae. 212 PORIFERA. II. 1880. Melonanchora elliptica O. Schmidt, Spong. des Meerbus. von Mexico, II, 85, Taf. IX, Fig. 8A--F. Fristedt, Vega Exp. vetensk. Iakttag. IV, 454, PI. 25, figs. 51—55. 1S92. — Herdman, Trans. Liverp. Biol. Soc. VI, 85. 1892. Topsent, Resultats des Camp, scient. du Prince de Monaco, Fasc. II, 101. 1903. — Arnesen, Spong. von der norweg. Kiiste, Berg. Mus. Aarb. 1903, No. 1, 17, Taf. II, Fig. 4, Taf. V, Fig. 4. 1904. Topsent, I.e. Fasc. XXV, 177, PI. IV, fig. 10. Massive, sometimes somewhat roundlobed. The surface closely set with higher or lower, wart- shaped pore papillce, otherwise smooth. The dermal membrane hyaline, very solid, with close-lying, liori- ' 1/ dermal spicules, supported by fibres of dermal spicules. Oscula spout-shaped , few , scattered ere// the pore papilla. The skeletal/ an irregular , chiefly potxspicular network of fibres passing towards the surface, and between them scattered spicules and spicula-bundles Spicula: Megasclcra : the skeletal spicules styli, often with rounded point, o-68 — o-86":"\ the dermal spicules tylota to strongyla o,4i—o'62mm; microsclera of three forms, sphcerancortz 0-054 — 0-068""", ancorm spatuliferce of two forms, large ones 0-042 — o-ojjj""", small ones 0-021 — 0-028""". This species is of a massive form; the smaller specimens are more or less roundish, the larger ones may be more expanded and somewhat roundlobed. The species has a very characteristic exterior, being rather closely set with wart-shaped papilla? of a peculiar structure, which will be more parti- cularly described below. The specimens in hand which are not torn off from the substratum, are attached to stones and shells. The largest specimen, which is of an irregular, massive form, but is no entire one, has a greatest extent of ca. ioomm and a greatest thickness of 55'""'. This specimen shows three flat, round eminences or lobes (PI. VII, fig. 4). Another, tolerably entire specimen is higher and more lump-shaped, it has a height of ca. 65™'" and a similar breadth. The smallest specimen is irregularly roundish, of a diameter of ca. 25""". The colour (in spirit) is whitish or yellowish white. The skin is firm and solid, but the consistency of the inner body is rather brittle. The surface is smooth without projecting spicules. The dermal membrane is a hyaline, very solid, and easily separable membrane, provided with close-lying spicules. Oscula and pores: As mentioned above, the surface is set with close-standing papilhe; these papillae, in their fully developed state, are formed as high warts, being cylindric and with rounded ends. They are not rarely broadest in their upper part, and the part below is narrowed somewhat like a neck. In their fully developed state they have generally a height of 4 — 5mm, aud a breadth above of 3 — 4'"'"; in some specimens, however, they may be somewhat larger. These papillse, which are supported by a network of spicules, have pores in the meshes of the net. The pores are close-standing, so that the membrane, which is here thin and transparent, becomes a sieve; they are round or a little oval, and their diameter was measured to 0-037 — o-i8mm. The pores are not only found in the upper part of the papilla;, but also down on their sides. The close spiculatiou of the dermal membrane ceases at the base of the papillae, and from this point polyspicular fibres issue passing up into the wall of the papilla aud forming a net of meshes, the single meshes of which may again be subdivided by thinner fibres or single spicules. In these meshes the pores are situated. This description holds good of the papillae, when they are fully developed. Besides PORIFERA. II. 2I, these, however, papillae occur in all degrees of contraction, down to quite small, knob-shaped project: the somewhat contracted papillae show only the net of meshes and pores at the top, and the entirely contracted, low knobs have neither the net of meshes nor pores. It is, of course, in: le to tell whether these different stages of the papillae represent si >j expansion and contraction, or they are stages of development, when they have not been observed to open 01 close. There is, however, every probability that the cpiestiou is of contraction and expansion, as the quite low knobs show a compact, more or less confuse accumulation of spicules, filling the knob entirely; then by di beginning of a net of meshes appears at the point, and the larger the papillae become, the n expanded and regulated the net of meshes becomes. If the question was of a development of new papillae, it was to be expected that the net of meshes was formed immediately, and that the papillae only grew in size. Carter says: Pores and vents respectively situated in the cribriform tubercl and Vosmaer supposes that the tubercles have nothing to do with pores, but are exclusively oscula. Now there can be no doubt that the papillae, to judge from their structure upon the whole, exclusively carry pores, neither are pores found anywhere else in the skin. The real oscula have been overlooked both by Carter and by Vosmaer, and they have not been mentioned by later authors either. These oscula are formed as conical spouts, which are formed by the dermal membrane; they may be higher or lower, sometimes they are very low, scarcely projecting, and then they are easily overlooked. The dermal spicules are lying in the oscular wall parallelly to the longitudinal direction of the spout. Oscula are only few in numbers in proportion to the pore papillae, thus on the la ;pecimen ca. eight were counted. The skeleton. The dermal skeleton consists of verv close-lying dermal spicules, all horizontal and situated in several layers. They are not scattered, but form groups in which the spicti parallel to each other. On account of the dense spiculation the membrane is very solid. The skeletal structure of the pore papillae and of the wall of the oscular spout has been mentioned above. To the dermal skeleton belong further fibres of dermal spicules rising perpendicularly from the skeleton below and supporting the membrane. The main skeleton is an irregular, to a great extent p net- work. Some fibres are found, running towards the surface; they are polyspicular, but may 1". rather varying thickness. When one succeeds in getting a section parallel to the di; if the fibres, they are seen to run rather regularly, especially near the surface; in their outer part the) consist of dermal spicules, and pass out to and support the dermal membrane. Transverse fibres are not found, but between the fibres a great many spicules are found, placed singly or a lew scattered quite irregularly between the fibres, so that the whole thing conveys a quit liar impression. A feature contributing to the irregularity of the skeleton is also the man r large canals, between which the fibres must bend. Spongin is found in the nodes of the skeleton and in the fibres, but it is white and clear. In the skeleton of the dermal membrane no spongin observed. Spicula: a. Mcgasclera. i. The skeletal spicules are mouactinal, most frequently styli, but often with the point so much rounded as to become strongyla, in which case, however, they preserve their mouactinal character, one end being thinner than the other. They are slightly curved, oftenest with the curve nearest tin- head-end, sometimes the curving is a little irregular. The point. 2I4 PORIFERA. II. as mentioned, may be varying, but is always short; from a distinct point, bounded by straight lines, but short, all transitions are found through shorter and more stubby forms to a broad rounding of the pointed end. In this respect there may be some difference in different individuals; in some, and perhaps in most, styli with quite rounded end are rare, while in a few specimens they are most numerous. Their length varies from o-68 — o-86mra, and the thickness from 0-014— o-02imm, in some indi- viduals they scarcely reach this thickness. A few developmental forms occurred, the finest ones are all pointed, but they may be rounded already when rather thin. 2. The dermal spicules are tylota with very slightly swollen ends; not rarely almost no swelling is found, so that they become strongyla; they are straight or quite slightly fusiform. Their length may be rather varying, from 0-41 — o-62mm, not varying so much, however, in one individual, the thickness is ca. o-oo8— 0'0i7mm. The developed tylota have equal, or about equal ends, but a few quite fine forms were found, indicating that they are begun as monactinal. b. Microsclcra are sphseraneorse and ancorse spatuliferas of two sizes. 1. The sphseraneorse are the wellknown ancorse described by Carter as «melon-shaped auchorates . Carter supposed the common ancorse to be developmental forms of the sphseraneorse, which was in accordance with his general view of the growth of these bodies. Levin sen (Videusk. Meddel. fra Nat. For. Kobenhavu for 1893, 1894, 13 seq. Tab. I, Fig. 31 — 49) has already pointed out the error in this view, and he is the only author, who has given a complete, aud, apart from a single mistake, correct description of the sphseraneorse and their mode of growth. The sphserancora consists of four arcs, connected with each other at the ends, and forming right angles with each other, so that they form an ellipsoidal body. Each of the arcs consists of a principal part or axis and of a thin plate-shaped brim issuing from the outward-turned dorsal side of this axis; this brim folds round on eiter side of the axis and lies as a thin plate on either side of it; it is of about the same breadth as the axis of the arc, and it is seen to be finely and transversely striated. The sphserancorse are typical ancorse, as is shown by their development. The youngest stage observed consists of a thin shaft with three thin, rather long beginnings of teeth at each end: in contradistinction to the common ancorse no falx is developed here. The teeth now become longer during the growth, aud at the same time both they and the shaft become broader in the radiate direction; finally the ends of the teeth meet and coalesce, and the body that was begun as an ancora, consists now of four narrow arcs whose ends are joined, or of two ellipses intersecting each other at a right angle. The body now formed consists only of the middle or axial parts of the arcs, and as yet no striation is seen; in older stages the striation is seen to begin first along the dorsal side of the arc, but reaching by degrees farther iuward, until the striated lateral plates or brims are formed in their full breadth, and the sphserancora is complete. The striated brims correspond completely to the ake and tooth-plates of a common ancora. Strictly spoken, the term striated brims or plates is not quite correct, as it is seen distinctly by sufficient enlargement that the question is not of a brim with striae, but, on the contrary, of a series of close-standing, fine teeth; in developmental forms with beginning brims it is seen especially distinctly that the teeth are free, later they become a little broader, and then they adjoin each other closely, only their somewhat pointed end is then seen to be free. When the ancora is fully developed, the four arcs are quite equal; it may, however, generally be decided, which of the arcs is the original axis; on the three arcs formed by the coalesced teeth, PORIFERA. II. 2I- there is generally found, in the middle of the inner side of the axial | und notch, often bounded on either side by a small spur; on the fourth are, on the other hand, the arc that is the original axis, only a spur or a few spurs are found. The sphserancorse may be somewhat varyin appearance; they may especially be more or less highly arcuate, so that the ellipse may b shorter; the shorter and more highly arcuate ones are upon the whole more robust, and have arcs than the longer and more slender ones. These variations of the sphaerancorae are generally found in different individuals, while in one individual the variation is most frequently slight Furtli more or less monstrously or irregularly developed forms are seen; thus the ancorse m; omewhat twisted, and the consequence then is that the teeth do not meet; in this case tin lesce in an oblique way, or are left free. Sometimes the teeth do not reach their full length, so that the lescing remains incomplete, or does not take place at all, while in other respects the ancorae are fully developed. The description of the construction and mode of growth of the sphaerancorae given here is quite agreeing with Levinsen's observations, with the only exception of a few points. I. opinion is that two independent forms of sphaerancorae are found, smooth ones and striated ones ; but the smooth ancorae, as has been advanced here, are developmental stages of the striated ones, only they have yet got the striated lateral brims, which grow forth as the last feature, and may be * in their growing to greater breadth, so that we get a continuous series from the first stage to the finis sphserancorce (PI. XX, fig. ic — k). The reason why Levinsen has supposed two independent forms to exist, is that he regards the forms with free, not coalesced, but otherwise fully i !, striated teeth mentioned above as the developmental forms of the striated ancora. According to what has been stated above, there can be no doubt, however, that these ancora,- are quite complete and their growth finished; they have only a little shorter teeth than the other sphaerancorae, which leads to the fact that the teeth do not coalesce; they are. accordingly, to be regarded as monstrous forms. Levinsen is also surprised that he finds only very few of the developmental forms of the and no young ones, as he refers all the vounger developmental forms to the smooth ancora; these latter dev< mental forms are rather frequent, although the smooth ancora is far less frequent than the striated one; this latter fact is a matter of course, as the smooth ancora is a d< nental form. Levinsen, it must be added, says himself that it is the finding of the striated ancora with not-adjoining teeth, which causes him to suppose two forms, while he should otherwise have been inclini the sir. ancora as a developmental form of the striated one. The length of the sphaerancorae varies from 0-054 , and tin Ith, mea two opposite ares, varies from 0-024 -0-038""". 2. The ancorae of the large lorn. the common structure; they have a slightly curved shaft and three lanceol tli at each end, and . narrow ala of the same length as the teeth. The ancorae are somewhat varying in size, the length from 0-047— 0-075"""; lne variation, however, is not so large in one individual, as instances ma given 0-047— o-o6rm'", and °'°57 0-075""". The breadth is ca. A few developmental forms occurred; these, as already mentioned, may easily be distinguished from the developmental forms of the sphreraneora, as their beginning teeth at an earl) stage become high and narrow, 1. e. dev< a falx, while such is not the ease with the sphaerancorae. 3. The small anco of a similar 2I5 PORIFERA. II. form, their length is otm— o-028,m", and the breadth is ca o-oo7mm. The three forms of microsclera are found through the whole sponge; in the dermal membrane the small ancora may be seen, and on the lower side of this membrane the sphserancorse are found; in the pore sieves the sphserancorse and the small ancorse are of frequent occurrence, while the large ancorse are scarce. The sphserancorse are frequently, but not always, seen in the membranes of the canals in large numbers; they are placed perpendicularly with one end towards the lumen of the canal, and between them both forms of the ancorse are seen. The sphserancorse and the small ancorse are upon the whole most frequent, while the large ancorse are present in far smaller numbers. In this species cellules spheruleuses » occur so abundantly, that the tissue seems almost exclusively to be formed by them; they are roundish or irregular, filled with rather large, clear, some- what refracting granules. Their average size is ca. 0'0i7mm. They are seen in large numbers in the dermal membrane and especially in the canals of the membranes. Locality: Station 78, 6o°37' Lat. N., 27°52' Long. W., depth 799 fathoms; station 81, 6i°44' Lat. N., 27°oo' Long. W., depth 485 fathoms; station 90, 64°45' Lat. N., 29°o6' Long. W., depth 568 fathoms; further it has been taken at the Faroe Islands, southwest of Myggenses, depth 135 fathoms (Ditlevsen); north of Iceland, depth 58 fathoms (H. M. S. «Beskytteren>, Gemzoe), and at 62°29' Lat. N., 50l7' Long. W, depth 190 fathoms (Ad. Jensen, the cruise of the Alichael Sars» 1902). Six specimens in all. The localities are situated in the Denmark Strait, north and southwest of Iceland, and at the Faroe Islands. Geogr. distr. The species seems to be very widely distributed; it has hitherto been obtained between Scotland and the Faroe Islands (the « Porcupine ), Reksten Fjord, depth 200 — 300 fathoms (the Argo ), Bergen, 53 — 96 fathoms (Arnesen I.e.), the eastern coast of Greenland, depth 130 fathoms (Fri- stedt I.e.), in the Caribbean Sea (Schmidt I.e.), and at New Foundlaud, depth 673 fathoms, and the Azores, depths from 278 — 724 fathoms (Topsent I.e.). 2. M. emphysema O. Schmidt. PL XX, Fig. 2 a— d. 1875. Desmacidon emphysema O. Schmidt, Jahresber. der Comm. zur wissenschaft. Unters. der deutsch. Meere in Kiel, fiir 1872—73, 1875, 118. 1885. ? Melonanchora elliptica Vosmaer, Bijdrag tot de Dierk., 12. Afl., 3. Gedeelt, 31, PI. I, figs. 14 et 22, PI. IV, figs. 23— 34, PL V, figs. 69—72. 1903. Melonanchora emphysema Thiele, Archiv fiir Naturgesch. Jahrg. 1903, I, 392. Incrusting or massive. The surface set with wart-shaped pore papilla-, otherwise smooth. The dermal membra lie solid, with close-lying horizontal spicules, supported by perpendicular fibres. Oscu/a d, spout-shaped. The skeleton chiefly polxspicular, consisting of fibres passing towards the surface and sparsely connected by scattered spicules. Spicula: Megasclera op one form only, uniform throughout leton; they are tylofa with transitions to strougyla 0-44 — o-6i"""; microsclera oj three forms, sfi/i O'O^o- . ancorce spalulipcrcr of two forms, large ones 0-057 — 0'0j8"'m, small ones V ■ -O'ojo PORIFERA. II This species is incrusting, or, when growing thicker, of a inure massive form. In thi it is somewhat similar to the preceding species, being set with papilla- of a similar structure as in M.elliptica. In the quite incrusting individuals the papillae seem to In- wanting, and in those onh li thicker to be present in rather slight number. The species grows on various bottom material, sto shells, or more loose material. The largest specimen has a greatest extent of fully ,v>":", and is pro- vided with many papillae, two smaller, about incrusting, specimens have lew papillae, and an incrusting specimen with an extent of 15"™ and a thickness of ca. 2-^"v" shows no papillae. Schmidt d< the exterior of the species as Unregelmassige Knollen und Fladen , and Vosmaei figures a speci- men, which probably belongs to this species and seems to be regularly cushion-shaped, with an extent of fully 50,nm. Accordingly the species does not seem to equal the preceding one in size. Thi (in spirit) is grayish. The consistency is as in the preceding species or a little looser. The surface is smooth, without projecting spicules. The dermal membrane is also here a solid, easily separable mem- brane with close-lying spicules. Oscula and purrs: What was said with regard to oscula and pores in the preceding species, holds also good of the present one; also here pore papillae are found of different sizes and stages of development, and conical, spout-shaped oscula. The skeleton. The dermal skeleton, as in the preceding species, consists oi spicules King hori- zontally in the membrane and arranged in more than one layer, In the present species they are generally not so close-lying as in the preceding one, but with regard to this fact some variation may be found in the present spiecies; where they are least close-lying they are scattered without any order, and the membrane may everywhere be seen between them; where the\ are most close-lying, a tendency to an arrangement in bundles may be observed. The skeletal structure in the pore papillae and the oscular walls is like that in the preceding species. The main skeleton is almost exclusively poly- spicular; some rather powerful fibres are found passing from the base towards the surface and towards the dermal membrane, which they support. The fibres are only mutually connected to a very slight degree, and generally only by single spicules which are irregularly scattered and only found sparingly. The polyspicular fibres may attain a thickness of 0-09 — o-i2mm. In the lower part of the sponge, which is turned towards the underlayer, sand ami gravel is generally embodied copiously. Spongin is found in the nodes and in the fibres, it is wdiite and clear and therefore not easily observed; it is not copious although distinctly present, and it seems often to coat the fibres completely, but with a scarcely per- ceptible layer. Spicula : a. Megasclera are of one kind only, and consequently of the saute form in the dermal membrane and the other piarts of the skeleton. They are tylota with slightly swollen cuds, sometimes the ends are so slightly swollen, that the spicules approach to 01 are strongyla. The\ are straight slightly, most frequently a little irregularly, curved, ami the} are slightly fusiform. Tin from 0-44— o-6imm, and the thickness in the middle isO'OlO 1 n >i |'"". A few developmental tonus were found; they showed that the spicules are begun as monactinal; the finest one hid one end. rounded, the other short pointed; as long as the spicules are not fully developed, the\ show a rather distinct dii between the two ends, one being thicker, the other a little thinner with a most frcqucn; swelling; still in the fully developed forms this difference may often be seen. Tin- [ngolf-Expedition \ I. ■ 2Ig PORIFERA. II. It is a surprising- fact that in this species only one form of megaselera is found, composing both the dermal and the main skeleton. The question, it is to be remembered, is not of the skeletal spicules having become equi-ended and of the same size as the dermal spicules, but it is a real fact that onlv one kind is found. According to both form and development it is evident that the mega- sclera here correspond to the dermal spicules in the preceding species, and thus the skeletal spicules have disappeared. It would be interesting to examine embryos of the present species, for, the skeletal spicules being generally the megascleres occurring as the first in the embryos of the Myxillinse, they might possibly be found to be represented in the embryos of the species. b. Microsclera; these are of three forms, sphseraucorse and ancorse spatuliferae of two sizes i. The sphserancorse are of the same construction as in M.elliptica, but they have a peculiar form that may best be described as quadrangular-elliptical; their length is 0-050 — o-056mm, and the breadth, which is rather constant, the sphserancora being almost unvarying as to form, is ca. o-o28mm. A few developmental forms were found, showing the same kind of development as in the preceding species. On account of the difference as to size and the peculiar form of the sphserancora, its younger develop- mental forms may easily be distinguished from the corresponding developmental forms of the large ancora. 2. The large ancorse are also similar to the ancorse in M.elliptica, but they are a little more robust Their length is 0-057 — o-078uim, and the breadth is 0-021 — 0'025mm. 3. The small ancorse are of a similar form, their length is 0-024 — 0'030mm, and the breadth 0-007 — croiomm. Quite singly ancorse may be found which seem, as to size, to form transitions between the two sizes of ancorae. Of both forms developmental forms were seen, but only in slight numbers. All the microscleres occur throughout the sponge and in the dermal membrane; here, again, the sphserancorse are seen in large numbers in the membranes of the canals. The large ancorse occur in this species in larger numbers than in the preceding one, and the three forms are about equally frequent In the dermal membrane cellules spheruleuses are found copiously; they are seen, partly as distinctly limited cells of a size of about o-oi5mm, partly gathered to heaps of granules. They are colourless in spirit, with large, round, highly refracting granules. Remarks: This species was established by Schmidt 1. c. as Desmacidon emphysema, but with a description that rendered it impossible to recognize it; the sphserancora he took to be a diatom. As I have examined Schmidt's type specimen, I have been able to identify the species with cer- tainty. Thiele La has also examined Schmidt's species and has already shown it to be a Melonanchora, but another species than elliptica, Thiele supposes that Fristedt's species is also emphysema, which might also be indicated by Fristedt's description and figure; by examining his specimen I have seen, however, that it is elliptica. On the other hand it is to be supposed from Vos- maer's description and figure I.e. that he has had the present species before him. — In Bronn's Klassen und Ordnungen der Spongien Vosmaer, at p. 127, mentions Melononchora 11. sp., and says in a foot-note: Wird naher beschrieben in den zool. Resultaten der dritten und vierten hollandischen Nordpolexpedition . In Vosmaer's work on the sponges of the Willem Barents expedition 1880 — 8i, however, only .1/. elliptica is mentioned, so that the author presumably has arrived at the conclusion that the species was not different from this latter, what it must, accordingly, be supposed to have been nevertheless. PORIFERA. II Locality: Station 78, 6o° 37' Lat. N., 27 52' Long. W., depth 7mm fathoms; station 89, 64 45' Lat N., 270 20' Long. Long.W., depth 310 fathoms; station 94, 64 56' Lat. N., 36' [9' Long. W., depth 204 fathoms; station 97, 650 28' Lat. N., 270 39' Long. W., depth 450 fathoms; further it has been taken east of the Faroe Islands, depth 250 fathoms (Ad. Jensen, the cruise of the Michael Sars 1902). The Ingolf stations are situated in the Denmark Strait and southwest of Iceland. Geogr.distr, The species has hitherto been taken west northwest of Haugesund and southwest of Bukenfjord, Norway, in both places at a depth of ion fathoms (Schmidt 1. c), and (if Vosmaer's species be identical with the present one) off the northern coast of Norway at depths of 140 and 145 fathoms (Vosmaer 1. c). -»"0;»fVr*o-«- Plate I. Plate I. Page Fig. i. Cladorhiza oxeata n. sp. One branch is almost quite denuded. '/, 97 — 2. Esperiopsis pedicellata n. sp., sitting on Astartc craiata. '/, 16 3. Espcriopsis typichela n. sp., sitting on Hornera lichenoides, the flagelliform appendices are not to be seen. '/r 22 4. Esperiopsis villosa Cart. Broken off below, the dermal membrane partly torn off. Along the upper edge oscula are seen. l!s • 9 5. Esperiopsis forcipula 11. sp. The largest fragment, probably the upper part of a thick, leaf- shaped sponge; the skin wanting below, '/i I7 — 6. Mycale ovulum O. Schmidt, on Halecium sp.; a large irregular specimen. r/i 34 7. Mycale ovulum (J.Schmidt, on Hydrallmania falcata; rather large, irregular specimens, probably formed by coalescing, showing several oscula. sjl 34 8. Mycale ovulum O. Schmidt, on Ptilota plumosa ; egg-shaped specimens, each with one osculum; to the left a specimen with two oscula, probably formed by coalescing. I/J . 34 9. Artemisina arcigera O. Schmidt. Rather flat specimen, viewed about from above. I/I . . . no — 10. Artemisina arcigera O.Schmidt. A small specimen on a Brachiopod. :/i no - 11. Artemisina arcigera O.Schmidt. A higher specimen sitting on a fragment of a Sipho. '/I no & a ' .V ■ \ ! i Plate II. Fiar. i. 2. 4- 5- 6. 9- io. — ii. — 12. - x3- - 1+ *5- — 16. — r7- — 18. - '9 — 20. — 21. — 22. — 23- Plate II. Asbestopluma pennatula O.Schmidt The largest specimen, the lateral branches are long iove but grow shorter downward; below the stalk-coating is seen; at the lower end the sponge is broken off. In the axis embryos are seen, above in a single row, farther down in a larger crowding. 'A Asbestopluma pennatula O.Schmidt. A specimen with almost all the lateral branches long; below the stalk-coating is seen, it is rather thick. At the lower end the specimen is broken off. '/, Asbestopluma pennatula O. Schmidt. A small specimen with root; the stalk irregularly bent in an angular way, the stalk-coating is seen reaching about tip to the ramigerous part. ' , Asbestopluma pennatula O. Schmidt. A somewhat twisted specimen with all the lateral branches short and showing a swelling with embryos; the lower part is wanting. IfI. . Isbestopluma pennatula O. Schmidt. A root-part. 1/1 Asbestopluma pennatula (). Schmidt. A fragment showing the proportion between the length and thickness of the lateral branches. The canals of the axis are seen to shine through. ca. Asbestopluma bikamatifera Cart. A specimen with all the lateral branches long, viewed in such a position that the longest lateral branches are turned to the sides; the stalk- coating is seen reaching about up to the lateral branches. The specimen is broken off below. ' i Asbestopluma bikamatifera Cart. A specimen with very short lateral branches; the speci- men is almost entire and show a long root-part, which is angularly bent. The stalk- coating is seen about up to the lateral branches. [/i Asbestopluma f areata n. sp. The largest specimen; only one branch is entire, the others are broken off. Only the entire branch shows the small lateral branches. The upper bounding of the stalk-coating is seen on most of the branches. !/i . isbestopluma furcata u. sp. At the base of the branch to the right a row of embryos is seen, in the branch to the left a cavity, in which two embryos have been situated, is seen. Below the stalk-coating is wanting; at the very base the surface of attachment is seen. ", . isbestopluma cupressiformis Cart. A specimen with indistinct, coalescing lateral branches; above a leaf-shaped part. '/, Asbestopluma cupressiformis Cart. A leaf-shaped specimen. '/, Asbestopluma cupressiformis Cart., on Astarte sp. ; a large specimen with more or less indi- stinct lateral branches; from the Kara-Sea. */, Asbestopluma cupressiformis Cart. A small specimen with distinct, lateral branches arranged Page 44 44 44 44 44 44 51 in a somewhat row-like manner. 'A Asbestopluma lycopodium Levins, keels. ' ', The lateral branches at the top coalesced to longitudinal Asbestopluma lycopodium Levins., on Pectinaria hypcrborea ; from the Kara-Sea. '/i Asbestopluma lycopodium Levins. The upper end of a specimen, showing distinct longi- tudinal keels, ca. '"/, . Isbestopluma hydra n. sp., on a little stone, ca. ?/, Asbestopluma hydra n. sp., on a little stone. It is a specimen without branches, the upper surface of the end-swelling has projecting spicules and quite short protuberances, and the swelling is slightly ribbed, ca. 7/r Asbestopluma infuuitibulum Levins. The calyx compressed, the edge a little damaged; Er< mi the Kara-Sea. " /, Asbestopluma infundibulum Levins. A smaller specimen with the calyx slightly compressed; from the Kara-Sea. '/, . Isbestopluma comata n. sp., on a sponge-spicule. ca. 3/, ' Asbestopluma comata n. sp. The upper part of the sponge, ca. 7. 54 54 53 53 58 58 62 62 62 66 66 68 68 72 72 \ Jn 2/- > Plate III, Plate III. Page Fig. i. Cladorhiza gelida n. sp. Broken off above, and with some of the branches broken off. Base of attachment below. l/1 83 2. Cladorhiza tenuisigma n. sp. A denuded skeleton, showing here and there remnants of the fibres of the branchlets. Below an irregular coalescing is seen. I/I 87 3. Cladorhiza tenuisigma n. sp. Root-part, turned to one side and with bottom material attached. ' /, 87 4. Cladorhiza tenuisigma n. sp. Branch of a slender specimen with long branches, showing the swollen ends and the somewhat circular arrangement of the branchlets. In the stalk-part and the base of the branch embryos are seen to shine through. I/1 87 5. Cladorhiza tenuisigma n. sp. Branch of a robust specimen, '/i 87 6. Cladorhiza iniquidentata n. sp. Broken off above and below, and only one branch entire. '/, 91 — 7. Cladorhiza corticocancellata Cart. From two damaged branches the axis is seen to project; below the tissue is wanting. r/i 93 8. ( 'ladorhiza corticocancellata Cart. Denuded axes, showing irregular coalescings. The prin- cipal axis showing the rings formed by the basal parts of the fibres of the broken off branchlets. l/1 93 9. Cladorhiza corticocancellata Cart. Longitudinal section showing the chambered construc- tion. '/, 93 — 10. ( 'ladorhiza oxen fa n. sp. Richly branched upper part of a branch. I/1 97 T"*- Plate IV. Plate IV. Page Fig. i. ( ' hondrocladia gigantea Arm. Hans. '/2 102 2. Homceodictya flabelliformis Arm. Hans., somewhat damaged, the dermal membrane almost quite wanting. '/l 118 3. Homceodictya flabclliformis Arm. Hans. A small, club-shaped specimen. I/1 118 4. Dendoricella rhopalum 11. sp. Highly contracted specimen with very distinct grooves, arranged in a net-like manner, seen from the concave side; two oscula are seen. 1/l ■ I27 5. Dendoricella rliopalum n. sp. Less contracted specimen, showing three oscula. '/, 127 6. Myxilla incrustans Johnst. Massive specimen, seen about from above, with three oscular cones; the surface very grooved. !/i J32 7. Myxilla incrustans Johnst. Fragment of a specimen with tolerably smooth surface. 1/l 132 — 8. Myxilla rosacea Lieberk., growing on Hydroids. '/, 138 9. Myxilla fi in briata Bow. A rather large specimen, to the right below oscula are seen closely gathered, otherwise single and scattered. The surface damaged in places. I/l 141 - 10. Myxilla fimbr lata Bow. A smaller, roundish specimen, sitting on a shell of a Brachiopod; the skin wanting to a great extent. \l1 141 — ri. Myxilla brunnea Arm. Hans. A leaf-shaped specimen, the dermal membrane partly torn off- 'A 144 Plate V. Plate V. Page Fig. i. Myxilla perspinosa n. sp., growing on a Hydroid. '/, 147 — 2. Myxilla pedunculata n. sp., growing on Area sp. 1/1 148 3. Myxilla diver siancorata n. sp., somewhat damaged and broken off below, >/i I5° — 4. Myxilla pluridentata 11. sp. The largest specimen, seen from the side and somewhat from above. '■', 151 5. Lissodendoryx lobosa n. sp. At the base two shells of Forarninifera are seen, '/i x54 6. Lissodendoryx Sophia Frstdt, somewhat damaged, the dermal membrane wanting in a few places; below the place of attachment is seen. I/l 156 7. Lissodendoryx fragilis Frstdt. Fragment of the lower part of a specimen, above a surface of fracture. '/, 158 8. Lissodendoryx fragilis Frstdt. Leaf-shaped fragment. 1jl 158 9. Lissodendoryx dwersichela n. sp., somewhat damaged, the lower, forward-turned surface is the surface of attachment. t/I 160 - 10. Lissodendoryx indistincta Frstdt. A somewhat compressed specimen, seen from above; the dermal skeleton more conspicuous in some places than in others. I/l 162 - 11. Lissodendoryx complicata Arm. Hans. A very richly branched specimen, '/i *66 - 12. Lissodendoryx vicina n. sp. A fragment. t/I 169 - 13. Lissodendoryx stipitata n. sp., attached to a stone, the dermal membrane wanting. 1/I . . 170 :« Plate VI. Plate VI. Page Fig. i. Iophon piceus Vosm. A very typical specimen, seen from the pore side; on the ridges the dermal membrane is mostly wanting. '/, 175 2. lopliou piceus Vosm. A somewhat irregular specimen, seen from the oscular side. J/i . . 175 3. lopliou dubius Arm. Hans., growing on Plumularia sp. '/i I8o ■ 4. lopliou dubius Arm. Hans. A specimen with free branches, broken off below. r/i I8o — 5. Iophou dubius Arm. Hans. A specimen with partly coalesced branches. '/, 180 ■ 6. lotrochota oxeata n. sp. An about lump-shaped specimen, growing on a fragment of Tln- nea muricata. l/l 186 7. lotrocliota polydentata n. sp., seen from the pore side, somewhat damaged, '/i J92 ■ 8. lotrochota spinosa n. sp. Broken off below. I/I 195 Inyolf /:' r/u ditioiit n I '1.2 * J * 1 ; f «L. ' . « ■* \ ' ' >.' * • r ■• ■ * V* • * • ••. * r r ■^rf k Plate VII. Plate VII. Page Fig. i. Forcepia Thielei n. sp. Seen from the pore side; the surface damaged in a few places. -/, 206 2. Forcepia Thielei n. sp. Seen from the oscular side, showing oscula, partly quite open, partly quite closed, and in different degrees of closing. 2/3 206 3. Forcepia Topscutii n. sp. The papillae damaged in a few places, so that the canal at their base is seen, '/i 2°4 — 4. Melonanchora elliptica Cart. The contour somewhat damaged; five oscula are seen. '/, 211 5. Melonanchora elliptica Cart. Pore tubercle, seen from the side. ca. "/t 211 — 6. Melonanchora elliptica Cart. Pore tubercle, seen from above, ca. "/, 211 (■ <4 * *; r« rX'. . - - • ■ - vt> • • 9 * . s*l * P « 6/« 0 ( • c w V < i j ■ 4 # § ..>.. ;ro \ i 1 \m j I • «v ^ Plate VIII. Plate VIII. Page Fig. i. Esperiopsis villosa Cart, a styli, b two developmental forms, x 165, c— g isocheke palmatse, c the large chela, side view, half front view, and front view, the latter a little contort, d older and younger developmental form, x 585, e the middle chela, front view and side view, f developmental form, side view, and younger and older developmental form, front view, x 5S5, g the small chela, front view and side view, x 700, h sigmata of different sizes, i three developmental forms, x 380 9 2. Esperiopsis Normani Bow. a styli of different sizes, b three developmental forms, x 165, the two styli to the right and the developmental form to the right are from a specimen with smaller styli, c isochela palmata, front view and side view, d developmental form, x 1000 13 ■ 3. Esperiopsis sp. QAlderi Bow.) a styli, x 165, b isochela palmata, side view and front view, c a developmental form, x 1000, the figured chela; show the peculiarity of the bending in of the axis in a marked degree 15 ■ 4. Esperiopsis pedieellata n. sp. a styli of different sizes, b three developmental forms x 165, 1 isochela palmata, front view and side view, x 1000 16 5. Esperiopsis forcipiila 11. sp. a styli, b two developmental forms, x 165, c the points of dif- ferent styli, x 380, d isochela arcnata, side view and front view, e an older develop- mental form, x 585, f the small isochela palmata, front view and side view, one with curved, the other with straight middle part of the shaft, x 1000, g sigmata of different sizes, h two developmental forms, x 585, i forcipes, x 1400 17 Plate IX. Plate IX. Page Fig. i. Esperiopsis ftagellutn n. sp. a styli, b a developmental form, x 165, c large isochelse pal- mate of different sizes, front view and side view, x 585, (/ small isochela palmata, front view and side view, x 1000; e sigmata of different sizes, / a developmental form, x 255, g flagellate sigmata of different sizes, h a developmental form, x 255 20 2. Esperiopsis typichela n. sp. a styli, x 165, b large isochela palmata, front view and side view, x 585, c small isochela palmata, front view and side view, x 1000 22 — 3. Esperiopsis typichela n. sp. A piece from the surface, showing the conical projections, pores, and the lower part of one of the flagelliform appendices, x 32 22 4. Esperiopsis typichela n. sp. The lower part of one of the flagelliform appendices, showing the central fibre, the layer of tissue with large and small chelae and rosettes, x ca. 54 22 5. Mycale placoides Cart, a styli of different sizes, b typical form of the shorter styli acting as transverse spicules, x 165, c upper end of different styli, showing the handle-like form in different degrees, x 380, d dermal spicules, showing the different length of the point and consequently of the whole spicule, x 165, e anisochela palmata, front view and side view, /chela with other dimension of the parts, side view, a little from behind, g chela seen from the smaller end, a little from behind, // chelae of smaller forms, front view and side view, i developmental form of a smaller and a larger chela, x 585, k sigmata of different sizes, x 585, / trichodragmata, x 380 24 - 6. Mycale lingua Bow. a styli of different sizes and with different ends, b two typical forms of the shorter styli, acting as transverse spicules, x 165, c isochela palmata, side view and front view, the sole representative of the genus from Greenland. The differences between the present specimen and tin- holotype of the species are so small that they might almost be ignored. They ate: the differences in the external form, difference of locality and the slightly longer distal rays of the hypodermal hexacts of the presenl specimen. Registered No. and locality: R. N. 6, 59 12' X. 5i°o5' W, Sch. vai 1870 fath-., bottom temp, 1 3. HEXACTINELLIDA Species 3. Malacosaccus floricomatus Topsent 1901, 1904A. Also Arnesen 1920. The characteristic external form of this species renders it readily recognisable. One specimen only is present. It is stalked and stands 4.5 cms. high. The colour, in spirit, is pale yellow. The remarks made by A 1 11 e se 11 (1920, p. 7) concerning this species are applicable to the present specimen but, all things considered, I am of the opinion that the specimens from the Azores, Bay of Biscay and Greenland may be regarded as representing a single species. Previously known distribution: — Azores (Topsent); Bay of Biscay (Arnesen). Bathymetric distribution: — 2300 — 2500 faths. Registered No. and locality: — R. N. 15. ii, stn. ^y, bo°iy' N, 54°o5'W, 1715 faths., bottom temp. i°4. Species 4. Leucopsacus ingolfi n. sp. (Figs. 2 and 2 a). It is of interest to record a species of this genus from the Greenland Seas which differs from the species described by Ijima (1903) from Japan in very small details only. There are two specimens present, the larger measuring about 1 cm., the smaller about 5 cm. in diameter. Both agree in all details so that it will suffice to describe only the holotype, R. N. 70. The disposition of the spicules in the skeleton is exactly the same as that figured by Ijima (1. c. PI. Ill, fig. 37), and the same categories of spicules are present as in L. scoli- odocus Ij. In fact, the only differences between that species and the present one are slight differences in the structure of the spicules. The external form is sac-shaped, as in the Japanese forms. R. N. 78 contains a large number of ripe ova and embryos at an advanced stage of de- velopment. The wall is supported in the following manner. The dermal surface is smooth and is supported by a layer of oxypentacts whose proximal rays measure .4 mm. and whose tangential rays measure .18 mm. in length. The ends of these rays are slightly microspined and, in addition, there is the vestige of a distal ray. Oxyhexacts: Immediately beneath the dermal layer of pent- acts are several layers of long-rayed oxyhexacts differing little from the Embryo from LeZp'sacus ingolfi n. sp. oxypentacts except that the six rays are present and all of the same length. These spicules are very variable in size, each ray of a typical spicule measures on an average .3 mm. in length and is slightly microspined, especially at the end. They form the main skeleton of the sponge and extend from the line of the pent- acts to the gastral surface. There are no small gastral hexacts as in L. scoliodocus. Fig. 2. Fig. 2 a. Stauractin from same. X 44°- Ill \ \i I INI I I II. \ Oxydiacts: Smooth oxydiacts with microspined ends occur in the choanosome in bundle- arranged with no apparent order but lying for the most part parallel with the dermal and gastral surf. Microscleres. i) Hexactinose discohexasters: These spicules are very similar to the corres- ponding spicules of L. scoliodocus except that the terminal anchor teeth are only two in number. They are somewhat rare and confined to the inner half of the choanosome. Axial length, .07 mm. 2) Hexasterose discohexasters: These are much more abundant than the precedii daily in the periphery of the wall. The number of terminal or secondary rays on a single primary or principal ray is usually 4, but as few as 2 or as many as 6 may be found. The total diameter of the spicule varies a little but an average diameter is about .44 mm. The reproductive elements present in one of the specimens, R. N. 78, are of two kinds. The first ci of single cells about .030 mm. in diameter, whose nuclei contain conspicuous nucleoli. They are rarely met with but the few seen had every appearance of the typical sponge ovum. The second type of re- productive body present is, to all intents and purposes, a fully-grown larva. Examples of these are "i a pe- culiarly modified spindle shape which can be best appreciated by reference to the diagram (fig. l). They are about .2 mm. long and about .055 mm. across at the thickest point. The state of preservation does not permit of minute histological examination. There is a certain amount of similarity between these larvae ami those of VitrolUda fertilis Ijima (1904, PI. Ill, tigs. 20 and 21). The only spicules present in the larvae at this si of development are oxystauractins composed of a long proximal ray running almost the whole length of the larva and ending in three shorter rays set each at right angles to each other. No other developmental s1 were found. The present species differs from the only other Atlantic species of the genus, /.. scoliodocus Ij. var retroscissits Topsent (1904C) in the smaller size of the spicules and the fewer number of categories of micros- cleres. Registered Nos. and localities: — R.N. 70, 05 14 X, 30 ;o YV. 752 laths., bottom temp 2 I : R. N. 78°6i' 32. N. 11 30 W, 720 faths., bottom temp. 24. Species 5. Caulophacus arcticus (Hansen) Var. grcenlandica var. nov. Numerous stalks are present from various localities some of which bear at the end the remains of the sponge-body. Only one specimen is complete and it is on this that the identification of the variety is Presumably, the stalks and other fragments belong to the same species as the complete specimen re- ferred to. This bears a strong resemblance to C. arcticus (Hansen), as re-described and figured by Schulze 1903, both in external form and spiculation. The actual points by which the present examples differ from the- type of the last-named species are wry slight and certainly not sufficient to justify oui regarding the Ingolf specimens as re] itives of another species. Indeed, it is doubtful whether these differences are sufficiently important to warrant the formation of a variety. The following point is the only one on which the holotype of 11 ansen's species and the present variety from Greenland do not agree, viz:- the nunibei of secondary or terminal rays to the discohexasters. In HEXACTINELLIDA holotype, according to Schulze's figures (1. c. PI. I, fig. 3 — 7), these vary from 7 — 18 in number, while in the present forms the number varies from 4 — 12. C. lotus, the South Atlantic representative of the genus, is very similar to the more northerly species in many respects. In fact, it differs from it only in the presence of small, smooth-rayed hexasters. Nevertheless, R. N. 7 is so like C. latits in external form that I am tempted to suspect that the North and South Atlantic species, so called, are no more than geographical varieties. Registered Nos. and localities: — R. N. 7, stn. 113, 6o,°3i' N, 7°o6' W, 1309 faths., bottom temp. — ico; R. N. 19, stn. 112, 67°57' N. 6°44' W, 1267 faths., bottom temp. — i°i; R. N. 30, stn. 19, 6o°29' N, 34°i4' W, 1566 faths., bottom temp. 2% R. N. 39, stn. 118, 6S°27' N, 8°2o' W, 1060 faths., bottom temp. — i°o; R. N. 64, "Michael Sars" Stn. 102, -9/8 1902, 63°i3' N, 6°32'W, 975 faths., bottom temp. — o°5i. Species 6. Asconema setubalense Savile Kent 1870. Other references to this species are: — Marshall 1876; Schulze 1886, 1887, 1899, 1897; Agassiz 1888; Topsent 1892, 1904 A; Brondsted 1916; (for further references vide Schulze 1887, p. 113). By far the most conspicuous in the collection, numerically this species affords some interesting data on variations in the Hexactinellida. Altogether the collection contains some thirty specimens, many of which are extremely fragmentary but others are complete or nearly so. In the complete specimens the external form may be either cup- or goblet-shaped, attached directly by the base or carried on a short, stout peduncle. The smallest is more or less sperical, about 5 mm. in diameter and in appearance very like the various species of Leucopsacus. This lends support to the view expressed by various authors that the species of Leucopsacus are but young forms of sponges belonging to other genera. The largest is about 12 cms. high. The colour varies from white to grey, brown and green, in spirit. It was a matter of no small surprise to me to find, as I eventually did, that these thirty specimens were all members of one and the same species for not only did they differ in colour but the size of the oscules and pores and the texture of the sponges themselves were by no means constant. These all again were determined by 1 he variations in the structure of the skeleton and the varying sizes of the spicules composing it. In some cases the diacts of the skeleton are not numerous and but sparsely present while in others they are abundant and form the most conspicuous part of the skeleton. Sometimes the pentacts are relatively few in number. According as to whether the spicules are numerous or sparse so the texture of the sponge itself varies and since the former may vary considerably, so must the latter since it is dependent on the former. One other point may be re- cognised in this connection, that the size of spicules, varying considerably as it does in a species, influences the texture of the sponge. If we imagine two sponges, one in which the spicules are few in number and compa- ratively slender the resulting skeleton will be by no means so stout and well-knit as that of a second in which the spicules are not only more numerous but thicker. Two such sponges, representing these extremes, would present marked differences in appearence when placed side by side. I have little doubt that the fact that some of the present specimens are fragmentary while others are whole and unbroken is due in no small measure to HEXAI TINELLIDA these causes. I emphasize the question of texture and its variability because it has so often been used a specific character and in my opinion, il is one of the least reliable that may be chosen. We know thai the size of spicules varies considerably as also the proportions in which they ma; and since the texture of a sponge depends so largely on the skeleton it also must vary proportionately. Especially is ,: hen we remenber that other factors also influence preserved specimens, such as the age of the specimen, the mode of preservation, etc. The skeleton, when examined microscopically, exhibits a wide range of variation in the proportions in which the various spicules are present, in addition to the variations in the size of the spicules themseh For example, in one specimen the hypodermal pentacts were few in number and altogether masked by the enormous numbers of diacts present. In another the small pentacts were few in number. The actual dimensions of the various spicules varied enormously from one to the other of the thirty specimens examined. Regarding the microscleres, while the actual dimensions did not vary to any great extent it was noticeable that frequently one or other of the categories would be partially or even completely absent. This latter point recalls a similar condition found in Aphrocallistes beatrix (q. v.). The spining of the rays of the diacts and the larger pentacts was also found to vary from, on occasion, completely absent to abundantly present. Previously known distribution: — Coast of Portugal (Kent, Jeffreys. Thomson); Bay of Biscay (Norman); East Coast of North America (Schulze) ; Azores (Topsent); North East Greenland (Brendsted). Bath y metric distribution: — 93 — 800 faths. Registered Nos. and localities: — R. N. j.i, stn. 78, 6o°37' N, i~ 52' W, 799 faths., bottom temp. 4°5; R. N. 9, 84, stn. 25, 63°jo' N, 54°25' W, 582 faths., bottom temp. 3 3; R. N. 11, y^. stn. 28. 65 14' N, 55°42' W, 420 faths., bottom temp. 3°5; R. N. 12, stn. 7, 63°i3' N, 15 41' \V, 600 faths., .} 5; R. X. 14. 38, 76, stn. 90, 64c45' N, 29°o6' W, 568 faths., 4 4; R. N. 17, stn. 28, 65°i4' N, 55 42' W, 420 faths., 3 5; R. X. 18, stn. 94, 64c56' N, 36°i9' W, 204 faths., 41; R. N. 25, 43, stn. 143, 62 58' X, 7 09' W, 388 faths., —04; R. X. 32, 50, stn. 54, 6308' N, 15 40' W, 691 faths., 3°9; R. N. _]-. stn. 5;,, 63 15' X, 15 07' W, 795 laths.. ;,°o8; R. N. 46. stn. 59, 65' 00' N, n°l6' \V, 310 faths., - 0°i ; R. N. 47, stn. 76, 60 50' X, 26 50' W, 806 faths.. 4°i; R.N. 57, 67°i6'N, 11-15'W, 192 faths.; R.N.61, ".Michael Sars", stn. 35, 1902, <>_• ss' X. 1 50' E. faths.; R.N. 63, "Michael Sars", stn. 85, 1902, 62 '53' N, 9 6' \V. 245 faths.; R. X. 80, stn. 57 X. 13'02'W, 350 faths., 3 4; R.N.86, "Michael Sars", stn. 85, r.902, d.-'v,' X. 9 6' W, 245 faths.; R X 87, "Michael Sars" stn. 74, 10,02. Iiu'm' X, 5 39' W, 620 faths.; R, X. 88, 66 r.6' X, 26 8' W, 330 faths.: R N 89, "Ryders Exp." E. Greenland. Species 7. Rossella mortenseni n. sp. (Figs. 3 9). The two specimens referred to this species are of the usual Rossellid type and have the appearance somewhat of Acanthascus. R. X. 58, the holotype, is sub--phe11e.1l with a central gastral cavity opening at the apex. There is a well-developed basal tuft of long spicules and the general surface of the body is beset with long diacts projecting singly or in tufts. The colour is a dark brown throughout. The total diameter of the specimen is about 5 cms. The second specimen is slightly larger than the first and. but for the fact that The Ingolf- Expedition VI 4. 10 HEXACTINELLIDA the surface has been very badly worn away in places, there is no essential difference between the two. The third is a young form, about 1.5 cms. in diameter and resembles the young forms of Pheronema carpenteri so much that I had at first mistaken it for a young Pheronema. The skeleton is quite typical in structure. By far the most conspicuous element is the collection of diacts which rill the choanosome, many projecting at right-angles to the surface. The dermal spicules are pentacts and hexacts. The microscleres are of two sorts only, oxyhexasters and discohexasters. In one of my preparations a few large smooth-rayed hexa- sters were present, with rays .15 mm. long, which I regard as extraneous since a similar spicule has not been found in the other specimens. Spicules: — 1) Diacts: These are of the usual Rossella-type with spiny ends, of various sizes. They form the main skeleton, the majority of them being distributed in loose bundles in the choanosome while others project beyond, and at right-angles to, the surface. 2) Dermal pentacts and hexacts: The der- mal tissues abound with spined pentacts whose rays measure .12 mm. in length. Often these spicules are represented by hexacts or, more rarely, tetracts (figs. 4-6). 3) Hypodermal Oxypentacts: Schulze (1887) in his description of Acanthascus grossularia, says, "In the dermal skeleton, medium- sized, smooth, hypodermal oxypentacts occur, in which the proximal ray is radially disposed, while th e four long tangentials, intersecting at right angles, follow the superficial curvature of the sponge in being slightly curved in- wards". The smooth-rayed hexasters referred to above as being possibly extraneous may be spicules corresponding to those described by Schulze in the passage quoted. Certainly their tangential rays are curved and flexuous while occasionally the distal ray is absent so that the spicule is in effect a pentact. The apparent absence of this spicule from the second specimen may be clue to the fact that the dermal tissues have been seriously damaged and torn. 4) In addition to the diacts, the choanosome contains a few large smooth-rayed hexacts, the rays of which may measure 10 mm. or more in length. 5) At certain parts of the surface of the sponge, pleuralia may be seen projecting at right angles to Fig. 3. Rossella mortenseni n. sp. Slightly enlarged. •,( I IM 1 I IDA I I it for a distance of about i cm. At the distal end these bear a variable number of rays, usually 3 — 5, disposed parallel to the general surface each ray usually being nearly 1 cm. in length. Over the greater pari of the surface, these spicules are wanting and where they do occur one may no1 be sure that the variation in the number of rays may not be due to damage in which some of the rays were broken. A few oi these spicules show up well in the photograph (vide fig. 3). Microscleres: — 1) Oxyhexasters: Of the usual type with six short primary rays about 005 mm. long which bifurcate into two divergent, slightly flexuous rays aboul .028 mm. long. (figs. 8, 9). The rays Figs. 4—6 Dermal hexact, pentact and tetract of Rosella Mortenseni. ■ [8. Figs. 7—9- Discohexaster, Oxyhexaster, and Oxyhexaster with distorted rays from Rosella \! of these spicules are frequently irregular or distorted. This reaches its height in the young specimen referred to where about 30 % of these spicules are distorted as in fig. 9. 2) Discohexasters: Of the same size and shape as the oxyhexasters hut with a slight disc at the end of each ray (fig. 7). This type of microsclere is much less common than the previous form. Registered Nos. and localities,: -■ R.N. 58, stn. 166 "Thor", 057 metre-. 62 57 X. [9 58' W. 14 July '03. R. N. 2, 6304' N, 9 22.' \V, 202 laths. Species 8. Schaudinnia rosea (Fristedt) Synonymy: — Hyalonema rosea Fristedt [887. Schaudinnia arctica Schulze [899B, 1900A Schaudinnia rosea Lundbeck [909. Schaudinnia rosea Brendsted mi 1. There are two examples of this species presenl in the collection. R. N. si consists of a single 1 somewhat flattened, aboul CO ems. long and from 2 to .; cms. in diameter R. N. 52 consists of . fragments which, when pieced together, form a sponge sitnilai in appearance to the larger of the two 1 12 HEXACTINELLIDA in the specimen figured by Schulze (i.e. pi. i, fig. i). Undoubtedly these two specimens belong to the same species, for, although there are a number of minor differences between them they agree in the essential features. If a comparison be made between the descriptions and figures given byFristedt and Schulze for Hyalonema rosea and Schaudinnia arctica respectively, it is apparent that the only points of difference between the two species are: — a) the external form; b) the absence of discohexasters in the former ; c) the absence of spines on the hypodermalia. Taken altogether, these points seem sufficiently important to mark a separation into two species, but I think it can be shown that they are not so significant as may appear and that the two species are, in reality, one and the same species. a) The external form. The external form of Hyalonema rosea as figured by its author (I.e. PI. 26, fig, 5) resembles almost exactly any one of the fragments of R. N. 52. In other words, the specimen described by Fristedt was not, as its author supposed, a complete example of a "round", "compressed" sponge but a fragment of a tubular sponge. The fact that the "lower surface is a little concave" in Fristedt's type- specimens only goes to strengthen the view that they were portions of a tubular sponge such as that described by Schulze. b) The absence of the discohexasters. The discohexasters are rare in this species and it is not impossible that Fristedt may have overlooked them. On the other hand, their total absence from his specimen would not prove an insurmountable obstacle to the present view expressed above (cf. the presence or absence of the mieroscleres in Aphrocallistcs beatrix and Asconema setubalensc). c) The absence of spines on the hypodermalia. The spining of the rays of the Hypodermalia appears to be a variable feature for in R. N. 52 they are practically all smooth while in R. N. 51, 75°/0 of them are strongly spined (cf. my remarks on Asconema setubalcnse). The British Museum possesses a fragment of Schulze's holotype of S. arctica and a comparison of it with the two present specimens leaves no doubt in my mind as to the synonymy with Fristedt's Hyalonema rosea. Previously known distribution: — East Coast of Greenland (Fristedt, Lundbeck, Brondsted); .North of Spitzbergen (Schulze). Bathymetric distribution: — 50 — 500 faths. Registered No. and locality: — Forsblads Fjord, E.Greenland, 50 — 90 faths. Species 9. Trichasterina borealis Schulze 1899B, 1900 A. The species is represented by a single sac-shaped specimen about 1 cm. high and two bottles full of all fragments. The agreement between the single complete specimen and the holotype is very close in prac- tically all respects both macro- and microscopic. So far as the fragments are concerned, it is impossible to compare anything but the details of the skeleton. In this the agreement with the holotype is again evident jxcept in one respect, viz: — the presence of a discohexaster. No discohexasters were found in the holotype two of the specimens of the present collection assigned to this species these spicules, almost identical h those of Asconema setubalcnse (vide Schulze 1887, PI. XXI, fig. 11), were found to be present, abundantly HI.X.V MM I I II) \ in one but sparsely in the other. Leaving aside the question of the disco rs, for the moment, tl specimens from Greenland are quite obviously individuals of a single species, if we are to judge by the other details of the skeleton. All possess the extremely characteristic trichasters and the single complete spec- imen is so like the holotype as to leave no doubt as to their identity with Schulze's Assumi to be tlie ease, the presence of the discohexasters in two <>i the specimens need afford no obstacle. Ti microscleres are absent in one, sparingly present in another, plentiful in the third hut absenl in the holotype. Obviously we have yet another ease of the sporadic occurrenee of a form of microsclere, similar to that which obtains in Asconema setubalense, Aphrocallistes bocagei, etc., upon which I have already remarked. One may suppose that the holotype happened to be devoid of this particular category of spicule which, in reality, should be normally present in all members of the species. On the other hand, it is quite conceivable that the discohexasters belong properly to Asconema setubalense, which is apparently present in the Greenland - in large quantities, and not to the sponges in which they were found. In either case the value of the species, and of the identification is unaltered. Previously known distribution: — Arctic (Schulze). Registered Nos. and localities: — R. N. 55 — 56, No. 21, "Ryder Exp." 74 27' X. 15 20' \Y, 127 faths.; R. N. 67, "Belgica" Exp., yy 31' N, 18 24' W, stn. 45. Species 10. Hyalonema kentii (Schmidt Asconema kentii Schmidt 1880. Hyalonema kentii Schultze 1886, 1N87, 1893, 1899 A. There are two specimens which I propose to assign to this species. Unfortunately both are dry and one (R. N. 29) badly damaged. R. N. 83 can he identified as belonging to this species with a fair amounl certainty. The spicules are very clearly like those figured by Schulze (1887) but the external form i> slightly different to that so far recorded for the species. The sponge consists of a spindle-shaped body about 1.7s em-. long and .9 cm. in diameter at the thickest part, which is approximately at the centre. The lower pole hears a short tuft of long slender spicules about 1 em. long. At the other is a shallow depression surrounded by a thin margin and hearing in the centre a conical protuberance. The external appearance resembles thai H. apertum (vide Schulze 1887, PI. XXXVII, figs. 2 and 3). R. X. 29 consists of a spindle- shaped body about 3 cms. long and about 1 cm. in diameter at the centre. I have been unable to find any trace of the dermal layer or its spicules. There is no cup-shaped depression at the distal pole but the end of the sponge is sharply- pointed in a manner which suggests the conical protuberance of the other specimen. The sponge is anchored at the proximal end by a tufl of spicules 1.5 cms. long. From the incomplete spiculation of this damaged specimen there can he little doubt that it is a Hyalonema and very near to // ; Previously known distribution:— G. of Mexico and the Caribbean Registered Nos. and localities: R. N. 29, 83, 01 || N, 2700 \V. 485 faths., bottom temp. 6° 1. M HEXACTINELLIDA Species i i. Pheronema carpenteri Savile Kent 1870. Other references to this species are: — Cray 1S70; .Marshall 1876; Schulze 1886, 1887, 1893, 1904. Synonymy: — Holtenia carpenteri WyvUle Thomson 1869. — Carpenter and Thomson 1896. Barboza du Bocage 1871. This species appears from all accounts to be a very prolific member of the sponge fauna of the Atlantic Ocean. Thomson (1. c.) reports having obtained some 40 specimens at a depth of 500 faths. to the north of Scotland. The present specimens are ten in number including two very fine sponges 10 cms. high. The rest are of varying sizes, four of them being quite young, the smallest no more than 1 cm. in diameter. From the point of view of their spiculation all ten specimens belong without doubt to the above species but after having noted the slight differences in external form met with in even this small collection of sponges, I feel very strongly inclined to suggest that P. grayi represents nothing more than a variety of the present species. In fact. I am inclined to regard it as standing in the same relation to P. carpenteri as the various subspecies of Aphrocallistes beatrix do to .4. beatrix itself, in which latter case, although for the purposes of this report I have recognised the four separate subspecies, it is a very debatable point whether such action is entirely justi- fiable and whether we ought not abandon all names but that of the type species beatrix. Topsent (1904A) sums up very clearly and concisely what he considers the essential differences between the two species P. carpenteri and P. grayi, but I suggest that there is not one of the supposed differences which may not be due to the variations normal to a sponge species. In the Greenland specimens the colour varies from yellow to a greyish-brown, in spirit, while the shape is usually globular or slightly ovoid. The spicules of which the basal tuft is composed vary in the manner in which they emerge from the base of the sponge. In some cases they are collected in tufts, in others it is difficult to see any sign of tufts at all. In one specimen the base of the sponge was entirely devoid of a basal tuft and the projecting spicules were disposed in a manner regarded by Topsent (1. c.) as characteristic of P grayi. The very small specimens were exactly the same, in appearance, as the young forms of P. grayi figured by Topsent (1892, PI. V, fig. 8). Despite my strong convictions on this question of the validity of the species P. grayi, I do not wish to commit myself to a decided opinion without having first examined more material than it has been my good fortune to obtain, hitherto. Previously known distribution: — Atlantic Ocean, North of Zanzibar (Kent, Schulze). Bathymetric distribution: — 340 — 1600 faths. Registered Nos. and localities: — R. N. 1, stn. 81, 6i°44' N, 27 00' W, 485 faths., bottom temp., R. N. 49, stn. 84, 62°58' N, 25°24' W, 633 faths., bottom temp., 4°8; R. N. 59—65, "Michael Sars", stn. 79, 6i°£' N, 9 46' W, 450 faths., 1902; R. N. 60, 66, stn. 76, 59^9' N, 7°5i' W, "Michael Sars", 687— 580 faths., 1902. Ill XACTINEL1 IH.\ Species 12. Farrea occa Bowerbank. The following is a list of the references to this speeii Bowerbank 1862, 1869, Gray 1867; Kent 1870; Carter 1873, 1874, [885; Marshall 1876; Prii Schulze 1886, 1887, 1899A, 1900B, 1902, 1904; Topsent 1892, [901A, [901C, 1904A. There are several fragments belonging to the genns Farrea which I assign with some hesitation to this species. In all cases little more than the main skeleton is left, often coated with incrustations of Hamacantha johnstoni, while the loose spicules have in most cases disappeared entirely so thai there can be no certainty about the identification of these fragments. However, since the main skeleton is very like that of F. and since the latter species is found abundantly in neighbouring seas it may be fairly safely assumed, I think, that the Greenland fragments are of the same species. Previously known distribution: — Cosmopolitan. The following is a comprehensive list oi localities recorded for this species, given for the first time: — Coast of Portugal, Japan (Carter) ; Japan, Manila, California, Indian Ocean generally (Schulze); Azores, Antarctic (Topsent). (Topsent E892D gives the Antilles in addition to those recorded above but at the moment I am not clear as to the source of his information oir this point). Bathymetric distribution: — 130 — 775 faths. Registered Nos. and localities: — R. N. 8, stn. 81, 61 44' N, 27 00' W, 485 faths., bottom temp. 6°i; R. N. zy, 28, 5$, 42, 45, 82, stn. yS, 6o°J7' N, 27':'52' W, 799 faths., bottom temp. 4 5. Species 13. Aphrocallistes beatrix < ,ra\ [858. In 1904, Schulze showed that the six known species oi Aphrocallistes represented nothing more than two real species A. beatrix and A. vastus, and that all the others were but varieties of one or other of these two. A concise and lucid resume of the conclusions reached by that author are given byArnesen (ig20,p. 10). The result of Schulze's work was, in effect, to establish this fact, that the species mighl be conveniently di- vided into four subspecies, the basis for distinction between them being the external form. Since then I jima (i()i6) has described a fifth, subsp. orientalis. Before proceeding further I propose to tabulate a complete list of the references to the various subspecies. Species Aphrocallistes beatrix Gray. Subspecies 1. A. beatrix beatrix Gray. Gray 1858; 1867; Carter [874; Marshall, C876; Priesl [884; Schulze [886, [8S7, [895, [900B, 1902, 11)04; Stephens 1915; Ijima [916; Arnesen r.920. Subspecies 2. A. beatrix bocagai Wright. Wright 1870; Kent [870; Schmidl 1870, c88o; Cuter [874; Marshall 1876; Schulze [886, t8! 1895, 1899A, 1900B, [902; Agassiz r888; Kirkpatrick [889; Topsenl [892, [904A. Subspecies 3. A. beatrix ramosus Schulze. Schulze r886, [887, [895, [902; Topsenl [892. HEXACTINELLIDA Subspecies 4. A. beatrix azoricus Topsent. Topsenl moiB, 1904 A. Subspecies 5. A. beatrix orientalis Ijima. 1916. The Ingolf material consists of a number of fragments of various sizes belonging to the subsp. bocagei Wright. Previously known distribution: — Subsp. I, Indian Ocean; subsp. 2, cosmopolitan; subsp. 3, Pacific Ocean; subsp. 4, Atlantic; subsp. 5, Pacific. Bathymetric distribution: — 70 — 600 faths. Registered Nos. and localities: — R. N. 5, 44, stn. 89, 64°45' N, 27°2o' W, 310 faths., bottom temp. 8 4; R. N. 10, 26, 77, 85, stn. 9, 64°i8' N, 27° 00' W, 295 faths., bottom temp. 5°8; R. N. 34, stn. 7^, o_> 58' X, 23°28' W, 486 faths., bottom temp. 5°5'; R. N. 69, stn. 10, 64*24' N, 28°5i' W, 788 faths., bottom temp. 3°5; R. N. 72, stn. 81, 6i°44' N, 27°oo' W, 485 faths., bottom temp., 6°i ; R. N. 74, stn. 97, 65°28' N, 27°39' W, 450 faths., bottom temp. 5°5. Species 14. Hexactinella grimaldii Topsent 1890, 1892, 1904A, 1904B. The species is represented by a number of fragments of what were presumably lamellar or semiin- fundibular sponges. One fairly large fragment bears what might conceivably have been a stout stalk but the fragments are too small to say anything definite concerning the external form. The agreement with the holo- type is very close in all details except that the rays of the large hexacts are longer, a very minor point, and the scopulae appear to have 4 rays, invariably. Previously known distribution: — N.Atlantic (Topsent). Bathymetric distribution: — 275 — 800 faths. Registered Nos. and localities: — R. N. 4, stn. 53, 63°i5' N, I5°07' W, 795 faths., bottom temp., 3°o8; R. N. 16, 31. i, stn. 21, 58°oi' N, 44°45' W, 1330 faths., bottom temp. 2°4; R. N. 20, stn. 19, 6o°29' N, 34°I4' W, 1566 faths., bottom temp. 24; R. N. 22, 28, 33.1, stn. 78, 6o°37' N, 27°52' W, 799 faths., bottom temp. 45; R. N. 46, stn. 54, 63°o8' N, i5°4o' W, 691 faths., 3^; R. N. 48, stn. 84, 62°58' N, 25°24' W, 633 faths., bottom temp. 4°8; R. N. 70, stn. 46, 6i°32' N, 9°43' W, 643 faths., bottom temp. 4°i7. List of literature referred to. 1888. Agassiz, A "Three cruises of the United States Coast and Geodetic Survey Steamer "Blake". Vol II Bull Mus Comp Zool. XV pp. 170 — 179. 1920. Ariiesen, E. "Spongia. Report of the Scientific Results of the "Michael Sars" North Atlantic Deep Sea Expediti Vol. Ill, Pt. 2. [871 Bocage, Barboza du, J. V. "Sur l'existence de la Holtenia • arpt ntt 1 1 Ww ille-Thomson, dans les cotes du Portugal 1 J. Sci. Math. Vol ; 1871 pp 69—70. 1862. Bowerbank, J.S. "On the Anatomy and Physiology of the Spongiadae Part III " Phil Trans Ro) S01 vol. [52 pp [087 — 1135. is". 1 lit "A monograph of the siliceo -fibrous sponges Part II" Proc Zool Soc . London [869 pp ;_■ . 1014 Brondsted, H. V. 'Porifera". Conspectus Faunae Groenlandicae «Meddelelser om Grenland" XXIII Copenhagen I'M" Id "Report on the Porifera collected by the Danmark Expedition at North-East Greenland" Danniark Bkspeditiom Gronlands Nordostkyst 1906 — 190S. Bd ; ]ip 475 psi 1869. Carpenter, W. B. and Wyville Thomson "On Hexactinellids" Ann. Mag. Nat. Hist., London vol j [869 p i->o 1873 Carter. H. J. "On the Hexactinellidae and Listhistidae generally, etc " Ann Mag. Nat Hist , London vol. 1 _• is;; pp. 47- 1874, Id, "Descriptions and figures of deep-sea sponges and their spicules from the Atlantic Ocean dredged up on board 11 M S "Porcupine" etc." Ann Mag Nat Hist vol. 14 1874 pp 20; 1885. Ed. Report on a collection of marine sponges from Japan, made by Hr. J Anderson, F. R S." Ann Mag Nat, Hist., London vol. 13 1885 pp. 387 — 406. 1881. Edwards, II, Milne. "Compte rendu soinmuire d'une exploration zoologique fait dans la Mi' a bord du Navire de 1'Etat "I.e Travailleur" " Compt Rend Acad Sci , l'aris vol 93 [S81 pp. 876 SSi and pp 1 1 1885. Filhol, II "La vii au fond des mers" I, a Nature, Paris Ann 1 ; me Sem. pp (79 (io [887. Eristedt, K "Sponges from the Atlantic and Arctic Oceans and tin- Behring Sea :sk [aktta holm vol 4 1887 pp 401 — 471. [858 Gray, J E. "On Aphrocallistes, a new genus of Spon ca" Proc Zool S01 1. 011 Ion 1858 pp 11 1 [867. Id. "Notes on the arrangement of sponges, with the description of some new genera" Proc Zool S [870. Id "Notes on anchoring sponges (Pheronema, Holtenia " \nn Mag Nal Hist , London vol •■ 100; Ijima. I "Studies on the Hexactinellida Contribution III" hup Inn Tokyo vol tS pp 1 [904 Id "Studies on Hexactinellida Contribution IV" I Coll Sci Uuiv Tokyo Vol [8 \ii io:" Id. "Notes on Iphrocal ularlj with reference to the form oecurrin; japon vol o pp. [73 [83. [870 Kent, W S "Notice of a new Vitrei Plieronema ilist . Lorn > pp [8.2 [86 [889. Kirkpatrick, R. "Report of .1 deep sea trawling cruise oil the South West Coast o( Ireland, etc." Ann Mae. X.it [1 1.' mdon so] 1 1 889 p 1 pi ii|oii. Lundbeck, W. "The Porifera ol East-Greenland" Medd om Gro laud rol 1 pp (64 I 1,. [ngolf-Expi Jili i' VI. 4 3 l8 HEXACTINELLIDA Marshall, W. "Ideen obex die Yeruandschaftsverhaltnisse der Hexactinelliden" Zeitschr. wiss. zool. vol. 27 1876 pp. 113 — 136. 1886. IVrri. 1 < xplorations sous-marines" Paris 1886. l'ricst. 1! V. "On the IU-xactinellidae" Quekett Club Journ., London vol. 2 1884 — 6 pp. 8 — 15. 1870. Schmidt, O. "Grundziige einer Spongien-Fauna des Atlantischen Gebietes" Leipsic 1870. 1880. Id. "Die Spongien des Meerbusens von Mexico und des Caraibischen Meeres. Heft II." Jena 1880. Schulze, P. E. "Ueber den Bau imd das System der Hexactinelliden" Abh. Akad., Berlin 1886. Id. "Zur Stammgeschichte der Hexactinelliden" Abhandl. math.-phys. CI. der K. Akad., Berlin 1887 pp. 1 — 35. 1893. Id. "Revision des Systems der Hyalonematiden" Sitzungsber. der K.-pr. Akad. der Wiss., Berlin 1893 pp. 541 — 589. 1895. Id "Hexactinelliden des Indisehen Oceans. Th. II. Die Hexasterophora" Abh. Ak. Berlin 1895. Id. "Revision des Systems der Asconematiden und Roselliden" Siz.-Ber. Akad. Wiss., Berlin 1897 pp. 520 — 558. [899 A Id "Amerikanische Hexactinelliden nach dem Materiale der Albatross-Expedition" Jena. |B. Id. "Zur Histologic der Hexactinelliden" Sitz.-Ber. Akad. Wiss., Berlin 1899 pp. 198 — 203. 1900A. Id. "Die Hexactinelliden" Fauna Arctica Bd. 1 p. S7 — 108. 1900B. Id. "Hexactinelliden des indisehen Oceans" Abh. Akad. Wiss., Berlin 1899 — 1900 Physik. Abh. 1. 1902. Id. "An account of the Indian Triaxonida collected by the Indian Marine Survey Ship "Investigator" Calcutta 1902. Id. "Caulophacus arciicus (Armauer Hansen) und Calycosoma gracile F. E. Sch." Abh. Akad. Wiss., Berlin 1903 Phvsik. Abh. No. 1. [904 III "Hexactinellida" Wiss. Ergebn. deutsch. Tiefsee-Expd. Valdivia Bd. 4, 8. 1915. Stephens, J. «Atlautic sponges collected by the Scottish National Antarctic Expedition" Trans. Roy. Soc, Edinburgh Vol. 50 1915 2 15 pp. 423—467. Topsent, E. "Notice preliminaire sur les spongiaires recueilbs durant les Campagnes de l'Hirondelle". Bull. Soc. Zool. Fr. i> pp. 1.5— 71. [892. 'Contribution a l'etude des spongiaires des l'Atlantique Nord etc." Monaco 1892 pp. 165. 1901A. Id Notice preliminaire sur les eponges receuillies par l'expedition beige" Arch. Zool. exper. (3) T. 9 notes et revue pp. v-xvi. 1901B. Id. "Eponges nouvelles des Acores" Mem. Soc. zool. France T. 14 pp. 448 — 466. 1901C. Id. "Spongiaires" Result. Voyage Belgica Zool. [904A. Id. "Spongiaires des Acores" Result. Camp, scient. Albert de Monaco. Fasc. 25. 1904B. Id. "Notes sur les eponges du Travailleur et Talisman. II". Bull. Mus. Hist, nat., Paris 1904 pp. 195 — 200. 1904C. Id. T. e. pp. 372— 377. 1870. Wright. E. P. "Notes on sponges" Q. J. Micr. Sci., London vol. 10 1870 pp. 73 — 82. THE INGOLF-EXPEDITION i 895-- 1 896. THE LOCALITIES, DEPTHS, AND BOTTOMTEMPERATURES OF THE STATIONS Depth Depth Station Nr. Lat. N. Long.W. in Danish fathoms Bottom- temp. Station Nr. Lat. N. Long.W. in Danish fathoms Bottom- temp. Station Xr. 1 620 30' S° 21' 132 7°2 24 63° 06' 560 00' 1 199 2°4 45 2 63° 04' 9° 22' 262 5°3 25 63° 30' 54° 25' 5S2 3°3 46 3 63° 35' io° 24' 272 o°5 63° 5i' 53° 03' 136 47 4 64° 07' ii° 12' 237 2°5 26 63° 57' 52° 41' 34 o°6 48 5 64° 40' 12° 09' 155 64° 37' 54° 24' 109 49 6 63° 43' M° 34' 90 7°o 27 64° 54' 55° 10' 393 3°8 5" 7 63° 13' 15° 41' 600 4°5 28 65° M' 55° 42' 420 3°5 51 8 63° 56' 240 40' 136 6°o 29 65° 34' 54° 31' 68 0°2 52 9 640 18' 270 oo' 295 5°S 3° 66° 50' 54° 28' 22 i°°5 53 10 04° 24' 28° 5o' 78S 3°5 31 66° 35' 55° 54' 88 i°6 54 11 64° 34' 31" 12' 1300 i°6 32 66° 35' 56° 38' 318 3°9 55 12 64° 38' 32° 37' 1040 o°3 33 67° 57' 55° 30' 35 0°S 56 13 640 47' 34° 33' 622 3°o 34 65° 17' 54° 17' 55 57 14 64° 45' 35° 05' 176 4°4 4 4 35 65° 16' 55° 05' 3"- 3°6 58 15 66° 18' 25° 59' 33° -^°75 36 61° 50' 56° 21' 1 135 i°5 59 16 65° 43' 260 58' 250 6° I 37 6o° 17' 54° 05' •7'5 l°4 60 17 62° 49' 26° 55' 745 3°4 38 59° !-•' 51° 05' 1870 i'3 61 18 6i° 44' 3°° 29' "35 3°o 39 620 00' 22° 38' 865 2°9 62 19 6o° 29' 34° M' 1566 2°4 40 62° 00' 21° 36' S45 0 3 3 <>} 20 58° 20' 40° 48' 1695 >°5 41 170 10' 1245 2°o 64 21 58° 01' 44° 45' 133° 2°4 42 6i° 41' o°4 65 22 580 10' 48° 25' 1845 i°4 43 6l° 42' I0" II' 645 o°o5 66 23 60° 43' 56° 00' PlAiiklon N0I uied 44 6i° 42' 545 4°S 67 Lat. N. Long.W. Depth in Danish fathoms Bottom- temp. 01° 32' 61 32' 61° 32' 61° 32' 62° 07' 62° 43' 64° 15' 63° 57' 63° 15' 63° oS' 63° 33' 64° 00' 63° 37' 64° 25' 65°oo' 650 09' 65° 03' 62° 06' ,.i" 33' 61° 33' 61° 30' 9° 43' 643 4°I7 ii° 36' 720 204O 13° 40' 95° 3°23 15° 11' 3°>7 15° 07' 1120 2°9I 150 07' I02O 1 40 22' 6S 7°32 13° 32' 420 7°87 15° 07' 795 3°oS 15° 4°' 3°9 150 02' 316 5°9 15° 09' 68 7°57 13 02' 350 3°4 12° 09' J! 1 o°S 3IO o°i 12° 27' '-t o°9 13° 06' 55 800 4°o 1 04 1 19° 00' 20° 43' 112S 3°3 2 2° 30' 3°o Station Xr. 68 69 70 7' 73 7-1 75 76 78 79 80 81 82 83 I.at. N. 84 85 86 87 88 89 90 91 06' 40' 09' 63° 46' 12' 58' 17' 6] 57' 6l° 28' 6l° 28' 5o' 6o° 10' 60° 37' 6o° 52' 6) 02' .,i 44' 6i° 55' 62° 25' 36' 62 36' 62° 58' 63° 21' 65° 03' 65° 02' 58' 64° 45' ■ 1 45' 4-t' Long. W. 23" °4' 23° 28' 240 36' 25° 35' 25° 06' 26° 25' 26° 50' 26° 59' 27° 52' 2S0 58' 29° 32' 2 70 00' 270 28' 280 30' 260 01' 25° 30' 23° 56'a 290 06' 31° 00' Depth in Danish fathoms 843 589 134 46 197 4S6 695 761 829 780 806 951 799 653 935 4S5 824 912 472 401 633 170 76 no 76 310 568 1236 Depth Depth Bottom- temp. Station Xr. Lat. N. Long W. in Danish fathoms Bottom- temp. Station Xr. Lat. X. Long. W. in Danish fathoms Bottom- temp. 3°4 92 64° 44' 32° 52' 976 i°4 118 68° 27' 8° 20' 1060 — i°o 3°9 93 64° 24' 35° 14' 767 I°46 119 67° 53' io° 19' IOIO — i°o 7°o 94 64° 56' 36° 19' 204 4°i 120 67° 29' 11° 32' 885 — i°o 65° 31' 3°° 45' 213 121 66° 59' 13° 11' 529 -o°7 6°7 95 65° 14' 3°° 39' 752 2° I 122 66° 42' 14° 44' "5 i°8 5°5 96 65° 24' 29° 00' 735 I°2 123 66° 52' 15° 40' 145 2°o 4°2 97 65° 28' 27° 39' 450 5°5 124 67° 40' 15° 4°' 495 — o°6 98 65 |8' 26° 27' 138 5°9 125 68° 08' 1 6° 02' 729 — o°8 99 66° 13' 25° 53' 187 6°i 126 67° 19' 15° 52' 293 -o°5 4°3 100 66° 23' 14° 02' 59 °°4 127 66° 33' 20° 05' 44 5°6 4°i IOI 66° 23' 12° 05' 537 -o°7 128 66° 50' 20° 02' 194 o°6 3°6 102 66° 23' IO° 26' 75o -o°9 129 66° 35' 23° 47' "7 6°5 4°5 i°3 66° 23' S°52' 579 — o°6 130 63° 00' 20° 40' 338 6°55 4°4 104 66° 23' 7° 25' 957 — i°i 131 63° 00' 19° 09' 69S 4°7 4°o i°5 65° 34' 7° 31' 762 — o°8 132 63° 00' 17° 04' 747 4°6 6° I 106 65° 34' 8° 54' 447 — o°6 133 63° 14' 11° 24' 230 2°2 4° 1 65° 29' 8° 40' 466 134 62° 34' 10° 26' 299 4°i 3°5 107 65° 33' io° 28' 492 -°°3 135 62° 48' 9° 48' 270 o°4 108 65° 30' 12° 00' 97 i°i 136 63° 01' 9° 11' 256 4°8 109 65° 29' 13° 25' 38 i°5 137 63° 14' 8° 31' 297 — o°6 4°8 no 66° 44' "° 33' 781 — o°8 138 63° 26' 7° 56' 471 — o°6 in 67° 14' 8° 48' 860 -o°9 139 63° 36' 7° 3°' 702 — o°6 112 67° 57' 6° 44' 1267 — i°i 140 63° 29' 6° 57' 780 -o°9 "3 69° 31' 7° 06' 1309 — i°o 141 63° 22' 6° 58' 679 — o°6 6°9 114 70° 36' 7° 29' 773 — i°o 142 63° 07' 7° 05' 587 — o°6 8°4 "5 70° 50' S° 29' 86 o°i M3 62° 58' 7° 09' 388 -o°4 4°4 116 7°° 05' S° 26' 371 -°°4 144 62° 49' 7° 12' 276 i°6 3°i 117 69° 13' 8° 23' 1003 — i°o QL 5 D3 v.6A pt.l-A Danish Ingolf-Expedition, 1895-1896 The Danish Ingolf- expedition BioNbd PLEASE DO NOT REMOVE CARDS OR SLIPS FROM THIS POCKE UNIVERSITY OF TORONTO LIBRARY