Sponges Jrom South Australia. 51 



sisting of a spiculo-fibrous, reticulated, dermal structure. 

 Vents on monticular elevations irregularly projected here and 

 there, chiefly over the upper part. Spicules of one form only 

 viz. acerate, 37 by H-6000th in. Structure internally com- 

 pact, much permeated by excretory canals. Size 2^ in. hio-h 

 by .3 X 5f horizontally. 



Depth 20 faths. 



Ohs. I have placed this specimen in the group Thalyosa 

 because the structure is more compact than that of the fore- 

 going species ; but really, at present, unless there is some 

 peculiarity in form to distinguish the species beyond what I 

 have mentioned in my Classification of the Amorphina, Isodic- 

 tyosa, Thalyosa, and Crassa [l. c. p. 177), the presence of the 

 acerate spicule alone in a massive amorphous structure for 

 this purpose, must, for the most part, in a single specimen, be 

 most unsatisfactory. 



Group 6. FiBULIFEEA. 

 5. Fihulia carnosa (provisional) . 



Fleshy, digitate, digitations branched ; or digito-palraate ; 

 or long cylindrically caulescent once or twice branched, ter- 

 minating in spatuliform bulbous ends ; the digitations of the 

 other forms terminating in contorted or crooked pointed ends, 

 like deformed wasted-away fingers. Consistence solid, fleshy. 

 Colour, when fresh, chiefly " black-red," now light brown. 

 Surface smooth, almost slippery. Vents small, respectively 

 projected on a papillary eminence, scattered generally over 

 the surface where the branches arc expanded, or in two lines 

 opposite each other, where they are cylindrically digitate, 

 that is Chalina-like. Spicules of two forms, viz. : — 1, skeletal, 

 smooth, acerate, 60 by lf-6000th in., more or less ; 2, flesh- 

 spicule, a minute simple C- and S-shaped bihamate (fibula) 

 about 2-6000ths in. long ; the former confined to the fibre 

 and the latter dispersed in the sarcode. Structure compact 

 and fleshy when wet, exceedingly hard and glue-like when 

 dry, contrasting then, in its brown colour internally, with the 

 white spiculo-fibre. Length of largest digitate specimen about 

 8 in. high by 4 x 1 horizontally ; that of the long caulescent 

 forms 12 in.; stem cylindrical, ^ in. in diameter; bulbous 

 ends about 3 in. long and I in. broad. 

 Depth o to 18 faths. 



Obs. This is a very remarkable sponge, partly on account 

 of the forms which it assumes, and partly on account of its 

 heavy, solid, fleshy consistence. I have placed it provision- 

 ally in the group Fibulifera under the above name, chiefly on 



4* 



