Sponges from South Australia. 453 



substance. When diy the body-substance, which is massive 

 and brown in colour, contrasts stronglj with the dermal layer, 

 which, becoming corrugated and more or less detached by 

 contraction in the line of the subderraal cavities, permits tlie 

 openings of the wart-like appendages to be seen from the 

 inner side, where they open into these cavities. Spicules of 

 two kinds, viz. skeletal and flesh-spicules : — 1, skeletal, 

 smooth, cylindrical, straight, slightly inflated at one end and 

 more or less obtuse or round at the other, about 100 by 

 l-6000th in.; 2, flesh-spicules of two forms, viz. bihamate 

 and equianchorate, the former C-shaped, elongate, about 

 9-6000ths in. long, and the latter slightly " angulate " in the 

 shaft, about 5-6000ths in. long, both belonging to the common 

 forms. No. 1 is the skeletal spicule generally and no. 2 the 

 flesh-spicule, which is most abundant in the clathrous struc- 

 ture of the wart- like appendages. Size of specimens, of 

 which there are three, now in their dry and corrugated 

 statCj about an inch high by 1|- in. in horizontal diameter, 

 each bearing ujnvards of forty wart-like appendages. 



Log. Port Western. 



Ohs. At flrst sight this species looks very like a Polymastia^ 

 especially P. rohusta^ Bk. (Mon. Brit. Spong. vol. iii. pi. x. 

 fig. 5), although not so like P. hicolor^ Cart., of these parts 

 {'Annals,' 1886, vol. xvii. p. 119), in which the nipple-like 

 process, instead of being clathrous in structure (like basket- 

 work) , is uniformly covered with a close villous surface, which 

 arises from the usual addition in Polymastia of a layer of 

 minute pin-like spicules intermingling with the sharp outer 

 ends of the large skeletal ones of the interior. In Polymastia^ 

 too, there are no flesh-spicules, ? excretory system as in Poly- 

 mastia. 



Our species, viz. Histioderma verrucosum^ is more nearly 

 allied to H. ajjjyeudiculatum, Cart., which was found among 

 the " Deep-sea Sponges " dredged up from the Atlantic Ocean 

 on board H.M.S. ' Porcupine,' of which I have given an 

 illustrated description (' Annals,' 1874, vol. xiv. p. 220, 

 pi. xiv. figs. 23-25), and to Halichondria jMyctenodes, also a 

 histiodermal sponge {ih. 1876, vol. xviii. p. 314, pi. xv. fig. 35). 



Histioderma jyolymasteides J n. sp. 



Very similar in all respects to TI. verrucosiim, but with 

 the '' wart-like appendages " a little larger, more pointed, 

 lanceolate, and the spiculation different generally. Ap- 

 pendages pointed, leaf-like in outline, i. e. when compressed, 

 about ^ in. long and 2-8ths in. in their greatest trans- 



Ann.(& Mag. N. Hist. Ser. 5. Vol xviii. 31 



