PORIFERA. I. 



n 



These fine bows I suppose to be developmental forms; to be sure, they are possessed of the recurved 

 points, but there seems to be no objection to the supposition that by a growth by mere apposition 

 the\- may attain the same form and size as the large ones. 2. Sigmata; these are small and of a 

 rather constant size; the length is 00128— o-oi5'"™ and may in a few cases reach o-oiS™"'; the thickness 

 is about o-ooi'""'. Toxa and sigiuata occur throughout the sponge, but are especially abundant in 

 the dermis. 



Locality: Station 2, 63° 04' Lat. N., of 22' Long. W., depth 262 fathoms, a calicular specimen; 

 station 3, 63° 35' Lat. N., 10" 24' Long. W., depth 272 fathoms, two leaf-shaped fragments; 63° 15' Lat. N., 

 9° 35' Long. W., depth 270 fathoms, a Httle fragment (Wandel); 72° 40' Lat. N., ca. 20° Long. W., depth 

 100 fathoms, a little fragment (the East-Greenland Expedition 1891 — 92). Accordingly the species has 

 been taken to the northwest of the Faroe Islands and off the northern East-Greenland. 



2. G. consimilis n. sp. 

 PI. XIV, Fig. 6 a— e. 



I Leaf- or fuiincl-shaped?). The skrlefoii consisting of numerous solid polyspicular fibres branching 

 through the sponge and forviing a solid skeleton. Rather small amount of spoiigin. Spicula: Megasclera 

 oxea 0-J26' — o-66""" ; microsclera toxa o'lig — o-ig""", sigmata o'oiS — o'0268'""'. 



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 — 6"'™, 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 i"™. 



The skeleton, as has been mentioned, is of quite the same structure as in the preceding species, 

 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. 



Spicula: 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, a. Megasclera are oxea; 

 these are slender, and evenly and long tapering; they are slightly curved, but rather frequent!)- the 

 curving is rather sharp, and then they may in form remind somewhat of the spicules of Halichondria 

 panicea. The length is between 0-528— 0-66""", and the thickness o-oi2— o-oi78'°™. A few shorter and 

 finer needles are seen. b. Microsclera: i. Toxa; these are of the same form as in the preceding 

 species; the length varies from ca. o-ii9— Q-ig'""', the thickness from ca. 0-004— o-oo5""" ; fine bows, deve- 

 lopmental forms, are also seen, but only in quite small numbers. 2. Sigmata; these are of a length of 

 0-018—0-0268""', the thickness is ca. o-ooi""". 



Both with regard to structure and spiculation this species appears to be very closely related 

 to the preceding one; but it is very well distinguished from this latter species by the size of the spi- 



