CAIATOSILVA CANTHARELLUS. 



91 



F. E. Schulze differs from it by its shape and by some of its spicules. In Aulascus 

 johnstoni all the pinules have a properly developed proximal ray, and discohex- 

 asters and discohexaster-derivate discohexactines occur. In Calycosilva can- 

 tharelliis many pinules have a reduced proximal ray, and discohexasters and 

 discohexactines are absent. Also the plumicomes are somewhat different. 

 Among the above mentioned related forms without pentactine hypogastralia, 

 Calycosoma gracile F. E. Schulze, which is not very different in shape and has 

 very similar onychhexasters and plumicomes, appears to be most closely allied 

 to Calycosilva cantharellus. The differences between the latter and the most 

 similar of the aUied forms {Aulascus johnstoni and Calycosoma gracile), let alone 

 the others, are so considerable as to necessitate the establishment of a new 

 species for its reception. 



Whilst I experienced no difficulty in coming to this decision about the estab- 

 lishment of a new species, I found it exceedingly difficult to decide whether this 

 new species should be assigned to one of the three genera mentioned, and if so, 

 to which one. Ijima ^ attaches little systematic importance to the presence 

 or absence of hypogastral pentactines and accordingly proposes to unite the 



1 1. Ijima. Studies on the Hexactinellida. III. Journ. Coll. sci. Tokyo, 1903, 18, p. 96. 



