SPONGESi- KALLMANN. 1^- 



likelihood of the latter species' identity with P. microcionides 

 would lead one to suppose, the retention in Phunohalichondria 

 of the species referred to, will be contrary to established prac- 

 tice. If this supposition be correct, the genus Clathrissa will 

 be a valid one, standing in the same relation to Leptosia as 

 Plumohalichotidria to Hymenancora. 



I was at first in doubt whether the specimens which are 

 labelled as the types of ClatJirissa arhuscida were genuine ex- 

 amples of the species, partly because the lengths of their 

 spicules do not agree very well with those which Lendenfeld 

 has given, but mainly on account of their lack of resemblance 

 to the figure {Loc. cit., pi. v., fig. 2). I am now, however, 

 quite sure in my own mind that this figure is wrongly repre- 

 sented as illustrating Clathrissa arbiiscula, inasmuch as it bears 

 a striking likeness to ordinary specimens of Clathiodendron 

 arbuscula, a species which is described in the same Catalogue ; 

 and I would therefore go so far as to say that the latter species 

 has been figured in mistake for the former. One can the more 

 easily conceive the possibility of such an error in connection 

 with these two species owing to the sameness of their specific 

 names and of the initial letters of their generic names. It is 

 confirmatory also of the opinion here expressed that the ex- 

 ample of Clathrissa arhuscida in Prof. Dendy's donation of 

 pieces of British Museum sponges agrees with the Australian 

 Museum specimens so labelled. The other discrepancy men- 

 tioned — that in regard to the lengths of the spicules — is of 

 negligible import, since Lendenfeld seems usually to have 

 taken the mean length of spicules into account, rather than 

 their maximum. 



A brief description of Clatlirissa arhiiscula may not be out of 

 place. The sponge grows in the form of a tussock of numer- 

 ous, prolifically multiplying, erect slender branches with highly 

 uneven, warty surface. Lendenfeld's description of the ex- 

 ternal features is fairly satisfactory, but requires some slight 

 emendation. It reads, "Small, irregular, lobose or digitate 

 sponges wih erect processes, attaining a height of 150 mm. 

 The living sponge is very soft and resilient, orange-red in 

 colour. Spirit specimens are brownish-grey. The whole of 

 the surface is covered with densely-situated villous, distally 

 rounded or thickened outgrowths, which are about 1.5 mm. 

 thick and from 2-8 mm. long." The description might sug- 

 gest that the sponge has a more massi\e basal portion, but 

 this is not so ; though the sponge is sessile and occupies an 

 extended base, the primary branches, except for occasional 

 anastomoses, are independent almost to the subtratum. The 



1 Ridley— ZooL ColL H.M.S. "Alert," 1884, p. 430, pi. xl., fig. G. pi. xlii.. 

 figs. a-a". 



