64 CAULOPHACELLA TENUIS. 



diameter, may be young forms of the large ones. Most of them, however, can 

 not be considered as such, since their end-ray bunches could not be converted 

 into end-ray verticils like those of the large discocomes by means of the apposi- 

 tion of silica-layers and since no silico-clastic process is known to occur in sponges, 

 which would make possible a conversion (development) of the end-ray bunches 

 of the small discocomes into the end-ray verticils of the large ones. 



Wilson {loc. cit., p. 48, 49) is inclined to consider the large and the small 

 discocomes as distinct forms, although he has himself observed transitions 

 between them. The discocomes observed by him had main-rays 16-50 ^ long, 

 and on each main-ray five to twenty or thirty end-rays 16-100 ^ long. 



Wilson {loc. cit., p. 43) examined fourteen specimens from Albatross Stations 

 3382 and 3399. Both lie off Panama, 3382 6° 21' N., 80° 41' W., 3399 1° 

 7'N., 81°4' W. The depth at these Stations, 3279 m. (1793 f.), 3182 m. (1740 f.), 

 is considerably less than at Station 4651 (2222 f.) where my specimens were 

 obtained. 



There can be no doubt that the specimens described above belong to 

 Caulophacus schulzei Wilson. Their similarity among themselves, and to 

 those examined by Wilson, is indeed remarkably great. This great similarity 

 makes it probable, first, that this species is very constant in character, and, 

 secondly, that the conditions of life are very similar at the three Stations 3382, 

 3399, and 4651. 



CAULOPHACELLA, gen. nov. 



Caulophacidae with oxyhexasters, without any other kind of microsclere. 

 The collection contains one fragmentary specimen of this genus, which 

 belongs to a new species. 



Caulophacella tenuis, sp. nov. 

 Plate 12, figs. 1-19. 



One fragmentary specimen of this sponge was trawled in the Eastern 

 Tropical Pacific, southwest of the Garrett Ridge, at Station 4732, on 21 Janu- 

 ary, 1905; 16° 32.5' S. 119° 59' W.; depth 3679 m. (2012 f.); it grew on a bot- 

 tom of Globigerina ooze; the bottom-temperature was 34.8°. 



The specimen is a thin lamella. To this the specific name refers. 



The only specimen in the collection is a fragment, measuring 15 by 8 mm., 

 of a flat lamella, about 1 mm. thick. 



The colour in spirit is nearly dark brown. 



