542 REVISION OF THE AXINELLID^, ii., 



skeleton. The only additional information pi'ovided regarding 

 the skeleton is to the effect that the " feste Axe" is similar in 

 character to that of the genus Acmdhella-. whether the radially- 

 directed styli are collected into fibres or not, or in what respects, 

 if anv, the several species differ in skeletal structure, is not 

 stated. Three of the species, — viz., C. expaiisa, C. erecta, and 

 C. ramosa, — agree in their described characters verj' closely, and 

 are undoubtedly congeneric; but the fourth, C. clavata, is dis- 

 tinguished not only by its non lamellar (cauliforni) habit and 

 conulose surface, but also by the fact that the megascleres are 

 of two distinct kinds,- styli composing the main skeleton, and 

 relatively few long flexuous strongyla (presumably occurring 

 interstitially). Since it is not unlikel}' that C. clavata will be 

 found to differ from the I'emaining three species in other import- 

 ant respects also, its inclusion in the present genus must be 

 looked upon as provisional. 



More recently Kirkpatrick(20) has described from Cape 

 Colony, under the name PhakeUia microxephora, a fifth species 

 with microxea, which it seems necessary al.so to include provision- 

 ally in the genus Ceratopsis. This species agrees with C. clavata 

 in the possession of elongated flexuous strongyla, but the accom- 

 panying megascleres are relatively few, and chiefly oxeote, and 

 the external habit of the sponge is lamellar as in the case of the 

 typical species of the genus. Concerning the structural char- 

 acters of the skeleton in this species, no information is available. 



By Thiele and Kirkpatrick, the oxeote microscleres were 

 regarded as indicative of affinity with the genus lligyinsia. 

 The evidence afforded by the spiculation of C. clavata and C. 

 microxephora, however, much more strongly justifies the view 

 that Ceratopsis is related to Siymaxia, and that it constitutes a 

 connecting-link between the latter and such genera as Axinella, 

 PhakeUia, and Acanthella. 



It is necessary to refer here to the species designated Axinella 

 frondula by Whitelegge(60), the spiculation of which has been 

 described as consisting of smooth styli of two sizes and of 

 scarce small oxea 110 by 3-5/x in size, occurring "chiefly in or 

 near the dermal portion of the sponge", — and which consequently 



