ATLANT. DEEP-SEA EXPED. 1910. VOL. IV.] 



SPONGIA. 



23 



Remark: The differences in the proportion of the 

 spicules, the presence of typical strongyla (generally not 

 with spinulation at one end as in Ridley and Dendy's 

 M. nobills), and the stronger spinulation in the larger 

 acanthostyli (in Ri dley and Dendy's M. nobills restricted 

 to the base) make it most probable, that this is not the 

 typical form of Anchinoe (Myxilla) nobilis, but rather a 

 variety of it, connecting this species still closer to the 

 allied Myxilla (ollm.) paupertas (Bow.) Vosm., especially 

 to the variety from the Azores (Topsent 41, p. 168). 



This is supported by the difference in habitat of the 

 two species: Anchinoe (Myxilla) nobills with its varieties 

 from the Challenger Expedition having been recorded 

 from the western part of the southern Atlantic (Rio de 

 la Plata, 600 fms., and coast of Patagonia), while Myxilla 

 paupertas is from the European side of the Atlantic. 



Locality: Between Gran Canaria and Cape Bojador 

 (Lat. 26° 6' N, long 14° 33' W); depth 39 m.; bottom 

 shingle. 



Axinelln polypoides O. Schmidt. 



Vide litter: 22. p. 62.. 



PI. IV, fig. 1. 



St. 37. One specimen. 



Sponge ramose, about 28 cm. high, devided into two 

 main branches, frcm which secondary branches dichoto- 

 mise, usually in cne plane from the inside of the two 

 main branches. The base of the stem is about 2 cm. in 

 diameter, and the branches about 1 cm. The transverse 

 section of the branches is oblong or nearly triangular. 

 -Towards the end they are more cylindrical and terminate 

 conically. Colour in spirit brownish. The consistency is 

 very firm owing to the strong axis of spicules. The corti- 

 •cal layer is rather thick and tough, but peels of readily. 

 The dermal membrane has been rubbed off,' mere patches 

 being left. Fine pores are spread all over the surface, 

 and at intervals larger, serially arranged, flat stellate 

 depressions (oscula) are to bee seen (though not very 

 distinctly on account of the bad condition of the specimen). 



Skeleton: The axis is very firm, consisting of 

 densely interwoven fusiform oxea, straight, or regularly 

 bent in the middle, 0.3700—0.4010 mm. long, with a 

 diameter varying from 0.0185 to 0.296 mm. The choano- 

 some consists of oxea, of the same kind as in the axis, 

 and of styli of about the same size (ordinarily 0.4010 mm. 

 by 0.0185 mm.); styli ar also to be found in the axis. 



Geographical distribution: This species has been 

 recorded from Lesina, usually in deep water, off the coasts 

 of England and Florida (23, p. 80) and off the Mediter- 

 ranean coast of France. 



Locality: Off Cape Bajador (Lat. 26° 6' N. long 

 14° 33' W); depth 39 m.; bottom shingle; bottom 

 tem-crnture 15.63° C. 



Thrinacbphora Ridley. 



Vide litter: 21, p. 193. 

 Thrinacophora murrayi sp. n. 



PI. IV fig. 2 & pi. V, fig. 5. 



St. 37. One specimen. 



Sponge erect, dichotomously branching in one plane, 

 thus having a fan-like outline. Height about 18 cm., 

 diameter of the stem about 15 mm. and of the flattened 

 branches 15—5 mm. Colour in spirit greyish yellow. 

 Texture tough, but flexible. Dermal membrane distinct 

 (mostly abraded). Pores rather small. Oscula seem to 

 be serially arranged, but are difficult to distinguish, the 

 specimen not being in good condition. 



Skeleton. The skeleton consists of a thick central 

 axis formed by a dense reticulation of strong fusiform 

 oxea and occasionally of styli cemented together by a 

 horny material, which gives the sponge its firm and elastic 

 character. The axis is coated by a comparatively thin 

 choanosome, which readily peels off. The choanosome 

 consists of a looser irregular reticulation of styli and oxea 

 like those in the axis. From the mesh-edges the spicules 

 project beyond the surface in small brushes. The long 

 setiiorm spicules forming the axis of the brushes in Thr. 

 cervlcomis Ridley & Dendy have not been observed. 

 The dermal membrane contains only trichodragmata and 

 isolated long, slender styli. 



Spiculation. Megasclera are straight or curved 

 fusiform oxea varying from 0.2960—0.4076 mm. in length 

 with a thickness of 0.0185 mm.; they occur especially in 

 the axis, but are also abundant in the coating. The styli, 

 especially abundant in the choanosome seem to be of 

 two sizes, the slender, smaller ones being 0.2730 mm. 

 long and 0.005 mm. thick, and the larger ones 0.5920 

 mm. long and 0.0185 mm. thick. They may be straight, but 

 are usually more or less irregularly curved. Microsclera 

 include only trichodragmata, about 0.040 mm. long and 

 0.010 mm. broad. 



It is impossible to identify this form with any one 

 of the earlier known species: Thr. cervlcomis Ridley & 

 Dendy Thr. funlformls Ridley & Dendy and Thr. 

 splnosa H. V. Wilson (45, p. 400) [Thr. spissa Topsent 

 has been removed to Rhaphisia spissa Topsent (41, p. 

 233) — and Thr Incrustans Kieschn. is a doubtful species 

 (33, p. 935)]. But it seems to be nearly related to the 

 two first mentioned inter se closely allied forms. 



Locality. The specimen was obtained between 

 Gran Canaria and Cape Bojador (Lat. 26° 6' N. long 14° 

 33' W), 39 metres on shingle; temperature 15.63° C. It 

 is thus the first known Thrinacophora from the Eastern 

 Atlantic (Thr. funlformls having been recorded from off 

 the coast of Brazil (Bahia), 7 — 20 fathoms, 77zr. cervlcomis 

 from off the Philippine Islands, 18 fathoms, and Thr. 

 splnosa Wilso:; frc::i c7: Costa Rica). 



