Sponges from South Australia. 283 



commensurately thin and flaccid, although still resilient ; con- 

 sisting of main and lateral branches, the main ones pursuing 

 an irregular course towards the surface without anastomosing, 

 and the lateral ones uniting the main filaments together 

 ladder-like, or through an intervening anastomotic reticula- 

 tion of their own, whose filaments are fixed to the surface of 

 the main fibre, with the central cavity of which, however, 

 that of the filaments does not communicate. Colour dark 

 amber. The whole, on desiccation, collapsing, from the thin- 

 ness of the walls, into a flimsy, resilient, skeletal structure. 

 Size of specimens, of which there are two, about 4 in. high by 

 6 in. in horizontal diameter. 

 Log. Port Western. 

 Ols. The fibre of this species is invaded by a branched 

 reticulated fungus, which traverses its central cavity, and thus 

 renders it identical with Bowerbank's representation of the 

 fibre of his genus " AulisJcia " (' Annals,' 1845, vol. xvi. 

 p. 405, pi. xiii. fig. 1), in which his " cfficoid canals " are 

 nothing more than the branches of a fungus or a " parasitic 

 alga," as Schmidt has stated long ago (Spongien d. adriat. 

 Meeres, 2nd Suppl. p. 10). It is somewhat curious that 

 of the four genera created by Bowerbauk in this paper (/. c. 

 p. 400 &c.), viz. Verongia, Aulishia, Stematumenia, and Car- 

 tilospongiQ, one only, viz. the first, should be tenable, since 

 " Aidiskia " is characterized by a parasitic fungus ; " Stema- 

 tumenia " also by the presence of a parasite, viz. Spongiophaga 

 communis J Cart. ; and " Cartilos'pongia^'' based on the struc- 

 ture of bone in the " body " of a vertebra from a young whale, 

 which may be seen among his specimens now in the British 

 Museum. It is extraordinary that a man of such extensive 

 microscopic experience did not see in his illustrations of the 

 latter [1. c. pi. xiv. fig. G &c.) the " oat-shaped cavities," the 

 " lacunar," and the " canaliculi " of osseous structure. Indeed 

 the odour of the specimen when I made a section of it was, 

 without anything else, suflicient to convince me of its nature. 

 There is another specimen which again, for distinction sake, 

 might be provisionally designated " massa,'' on account of 

 its slightly lobate massive form. I say " provisionally," be- 

 cause there appears to me to be a great variety of Aplysinoid 

 growths in the neighbourhood of " Port Phillip Heads," which 

 possibly (if altogether considered on the spot where they can 

 be easily obtained, as they should be) might be found to be 

 derived from only one or tw^o species. These varieties do not 

 appear to me to be so much in the soft parts as in the colour 

 and structure of the keratose skeleton. Thus in ApJysina 

 massa the colour of the fleshy part is dark grey and the 



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