STAUKOCALYPTUS. 165 



"With respect to S. soUd^is it seems that F. E. Schulze 

 (/. c, p. 52) regards it to be distinct from the closely similar 

 S. dowlingi mainly on the strength of two peculiarities, viz., that 

 the general shape is invariably barrel-like, straight and broad- 

 based instead of being cup-like, outbulged on one side and 

 narrowed towards the base ; and that the discoctasters are much 

 smaller and more slender-rayed. It occurs to me that perhaps 

 some other points might well be added to the specific difference, 

 to which view I am led from certain facts contained in F. E. 

 Schulze's own description and figures. On p. 105 (/. c), in a 

 short diagnosis of IS. solidus, is a statement to the effect that as 

 gastralia there occur a greater number of pentactins than hex- 

 actins ; whereas, in iS. dowlingi the same spicules are known to 

 be hexactins and only occasionally pentactins. Again, on his 

 Plate X. (/. c), F. E. Schulze gives figures of the dermalia 

 and gastralia from aS'. solidus; both the spicules mentioned are 

 shown to have rays which are basally quite smooth, instead of 

 being rough all over as in S. dowlingi. The differential characters 

 above indicated, if shown to be constant, would certainly be of 

 no small importance in distinguishing the two sj)ecies. 



Concerning the three new species descril)ed for the first time 

 in this Contribution (y/,r,, S. iubulosus, S. ajfinis and S. entacan- 

 thiis), it may here be mentioned that they are all very nearly 

 related to S. doivlmgi and that some of the specimens on which 

 they are based were at first referred by me to that species, 

 though with some hesitation. The characters of the specimens 

 referred to were therefore taken into account in drawing up the 

 diagnosis of S. dowlingi in my " Revision of Hexactinellids with 

 discoctasters " (Ijima, '97, p. 53). However, a renewed examina- 



