198 ART. 7. — I. IJIMA : HEXACTINELLIDA, IV. 



The oxyhexasters measure 100-1 o 2 /v. in diaiueter, tliiiy com- 

 ing next in size to the same rosette in ^S. dowlingi and ti/balosus. 

 A goodly number oF them are hemihexactinose, but I have found 

 none in quite hexactinose form. This negative character may 

 perhaps be regarded as one of the j^eculiarities of the species, or 

 at any rate of the particular specimen now being described. The 

 terminals are rather strong (often 4 fJ- thick at base), — stronger 

 than I have found them to be in other closely similar species of 

 the genus. Moreover, they are always rough, the roughness being 

 frequently develo[)ed into short barbs on the basal parts. 



Of the discociasters, those in the subdermal space measure 

 155-220/^ in diameter ; those in or near the endosome, 220-286/^. 

 It may be pointed out that the lower limit (155 //) in this range 

 of variation falls considerably below that in S. doivlingi (228 /i) 

 but coincides in an approximate way with the same in S. iubulosus 

 and ajjinis. In all of the discoctasters the principal is somewhat 

 shorter than, or sometimes nearly as long as the terminal tuft 

 belonging to it. The general appearance of the spicule agrees 

 well with that of the same in S. ajjinis. In no case, however, 

 have I noticed the six prominences on the sides of the central node. 



Jlicrodiscohexaslers I have failed to discover anywhere in 

 the specimen ; but, in view of the ease with which they might be 

 overlooked, I am not fully prepared to assert their total obsence. 



Now let me describe some points in the spiculation of the 

 smaller specimen (No. 40; > ; Contrib., IT!., PI. VI., ligs. 9 and 



