Sponges from South Australia. 303 



conuli, but in which the keratose fibre is strongly developed 

 and more or less cored with sand and foreign microscopic 

 objects. 



Stelospongus levis, Hyatt (op. et loc. cit.). 



Of this species, to which I have just alluded, there are 

 several specimens in Mr. Wilson's spirit-preserved collection, 

 while the great number of dried ones from the southern coast 

 of Australia that have come under my notice indicates that 

 it is not only abundantly plentiful, but that it is more so than 

 any other species in that locality ; yet, with the exception of 

 Dr. Bowerbank's representations of a spirit-preserved speci- 

 men from Freemantle under the name of ll Halispongia choa- 

 noides" (Proc. Zool. Soc. 1872, pi. vi.), and Mr. Stuart O. 

 Ridley's observations on Stelospongus excavatus from Port 

 Molle, in Queensland (Zool. Coll. of H.M.S. 'Alert,' Brit. 

 Mus. pub. 1884, p. 383), viz. that "the colour in spirit is 

 greyish white (putty colour)," and that " the dermis conceals 

 all the skeleton but the ends of the primary fibres, which ap- 

 pear as low points over the whole of the outer surface and 

 just inside the margins of the pits," there is no description of 

 anything more than the dried skeleton, which Schmidt, who 

 established the genus (Spong Atlantisch. Gebiet. p. 29, 

 Taf. iii. figs. 13 and 14), only illustrates by two fragments of 

 the fibre, which Hyatt fortunately has identified with an entire 

 form from Port Phillip Heads, Australia, under the name 

 above mentioned (op. et loc. cit. pi. xv. fig. 16). 



Returning then to Mr. Wilson's spirit-preserved specimens 

 of this species, we find them pyriform, stipitate, smooth, con- 

 sisting of a subglobular body presenting typically a single 

 large vent on the summit, terminated by an attenuated stem 

 and root-like expansion in the opposite direction. Consistence 

 resilient. Colour, when fresh, '" grey," as it is now. Sur- 

 face smooth, covered uniformly by dermal sarcode charged 

 with sand, which in its natural, that is unworn, state entirely 

 conceals the subjacent fibre under a sieve-like structure, 

 which is well represented by Dr. Bowerbank (op. et loc. cit. 

 pi. vi. fig. 2), in which the reticulation is densely arenaceous, 

 and the interstices, which are more or less uniformly circular, 

 tympanized by the dermal sarcode alone. Pores in the inter- 

 stices of the dermal reticulation. Vent very large, generally 

 single, and situated a little excentrically on the summit of the 

 body, supported on a tubular extension of the fibre, which is 

 better seen in the dried skeleton than in the fresh specimen, 

 where it is covered by a lip-like fleshy fold of the dermal 

 sarcode, whose arenaceous and poriferous structure ceases at 



