Sponges from South Australia. 317 



face fenestrally by an extension of the dermal membrane ; 

 the latter, which is black, supported on the subjacent fibrous 

 reticulations, whose knots here and there throw up a short 

 point which becomes the axis respectively of microscopic 

 conuli about l-80th in. apart ; this point, when projecting 

 through the dermal membrane, may be seen under the micro- 

 scope to consist of a simple pointed (? budding) end of the 

 fibre, generally cored with the usual rJocculent material, but 

 without any foreign bodies. Pores in the dermal membrane 

 over the interstices of the subjacent fibrous reticulation. Vents 

 circular, generally large, but variable in size, scattered nume- 

 rously over the surface among the anfractuosities. Fibre 

 remarkable for the uniformity of its character in point of 

 fineness and short branching, thus rendering the internal 

 structure soft but very compact; the larger filaments cored 

 with the usual flocculent substance, but no foreign bodies, 

 and the whole supporting the sarcode of the parenchyma, in 

 its interstices, traversed plentifully by the canals of the ex- 

 cretory systems, which present a black colour on their surface, 

 from being lined with an extension inwards of the black 

 dermis (?-ectodermic epithelial cells), and end in the vents 

 mentioned, among the " openings " of the " sinuosities," 

 which, also traversing the whole of the sponge, impart 

 1o it its anfractuous character both externally and inter- 

 nally. Size of specimen 1^ in. high by 6 X 4 in. horizontally 

 in its greatest dimensions. 



Hob. Marine. 



Loc. Port Phillip Heads, South Australia. Depth 19 fath. 



Obs. 1 have described this species from the dried specimen 

 in Mr. Wilson's collection ; but there is another spirit- 

 preserved one about the same size, which, in colour, is grey 

 now, but when taken is stated to have been " bright orange." 



Also in my cabinet there is a dry specimen of the same 

 species (apparently beach-worn) from the Mauritius, again 

 about the same size, in which, from half an inch into the 

 interior, the colouring-matter has been washed out, leaving 

 the fibre yellowish or sponge-colour, while within this again 

 it \c all dark purple, like that of the dried specimen in Mr. 

 Wilson's collection. 



Moreover, there are two other dry specimens in Mr. Wilson's 

 collection of a much larger size with the same characters as 

 regards form, above given, but whitish, the sponge itself appa- 

 rently having grown in the midst of fine sand, as there is as 

 much sand as fibre in it ; while in one of these specimens there 

 is the addition of iSpoiujiopltaga communis, to which 1 have 

 before alluded, whose filaments can be distinguished from the 



