ART. 12 



HEXACTINELLID SPONGES OKADA 



83 



The gastral hexactins, though somewhat shorter, are much more 

 robust than those of the type specimens, measuring mostly 12ix to 

 15/A broad at the base. The roughness of the surface, caused by the 

 existence of microspines, is also much more pronounced. 



Remarlis. — The present species somewhat resembles A. flssuratus 

 shimushirensis from the same station in the essential characters of 

 spiculation; but differs from it by the entire absence of the larger 

 microdiscohexaster and by the structure of the normal oxyhexaster, 

 which has the central knob well developed in the present species, 

 while absent in the latter. 



AULOSACCUS TUBERCULATUS. new species 



Figure 10 



This species is represented by three fragments (cotypes, U.S.N.M. 

 No. 22122), which may belong to the upper portion of the same 

 sponge (two fragments preserved in the same bottle are larger than 



Figure 10. — Aulosaccus tuherculatus, new species : a. Dermal hexactin, X 250 ; b, 

 gastral hexactin, X 250 ; c, hexactinic form, X 500 ; d, hemihexactinic form, X 500 ; 

 e, hemihexactinic form, X 500 ; f, macrodiscohexaster, X 500 ; a. microfliscohexaster, 

 X 500 



the third in another bottle). They were all obtained from a depth 

 of 244 fathoms, off Bowers Bank, Bering Sea (Station 4769). The 

 greater part of the dermal delicate latticework has fallen off, some 



