sponges from coastal beaches of n. s. "wales — whitelegge. 69 



Sub-family CHALININ^. 



Pachychalina, Schmidt. 



Pachychalina aurantiaca, Lendenfeld, Zool. Jahrb., ii., 1887, 

 p. 768 ; Dendy, Cat. Non-Calcareous Sponges, Proc. Roy. 

 Soc. Vict., n.s., vii., 1895, p. 241. 



A single example is here with some hesitation referred to this 

 species. This form is rather common on the coast. In habit it 

 varies from simple strap-shaped to palmate or digitate ; the branches 

 are generally flattened and about twice as broad as thick. The 

 margins are thin, and bear one or two rows of closely placed 

 vents, from 1 to 2 mm. in diameter; occasionally one or more 

 vent-bearing ridges are present on the anterior or posterior surfaces. 

 In well preserved examples there is a distinct dermal layer of 

 oxeate spicules, forming a white incrustation. The surface spicules 

 are held together by a minimum of spongin, hence beach specimens 

 are usually denuded of the dermal crust. The subdermal surface 

 is neatly reticulated, and exhibits numerous round pores, about 

 07 mm, in diameter, and from 05 to 1'5 mm. apart. 



The description given by Uendy agrees in the main, but the 

 spicules are rather stouter than in the example from Port Phillip. 

 (R.N. 823 Uendy). 



The spicules are slightly curved oxea, tapering gradually to 

 within two diameters of the ends, from thence suddenly to acute 

 points. Size — 0'14 by 0065 mm. 



In the Port Phillip specimen, the spicules (according to Dendy) 

 measure 0-14 by 0-004 mm. 



In length the spicules are pretty constant, but they vary con- 

 siderably in diameter. 



A fine specimen from Maroubra Bay is 450 ram. in height, the 

 main branch is 30 mm. wide and 15 mm. in thickness. 

 One example, from Tuggerah Beach. 



Pachychalina punctata, Ridley and Dendy. 



Pachychalina pimctata, Ridley and Dendy, Chall. Rep., Zool., xx., 

 1887, p. 24, pi. vi., figs. 2, 2ffl, 26, '2c, pi. xlvi., figs. 1 - 2 ; 

 Lendenfeld, Zool. Jahrb., ii., 1887. p. 776. 



Over twenty specimens of this common form are in the collection. 

 These have been compared with sections of the type from the 

 British Museum. The largest measures 400 mm. in height, 300 

 mm. in breadth, and between 40 and 50 mm. in thickness. The 

 sponge usually consists of a broad basal plate, from which arises a 

 compressed peduncle, about twice as high as wide, with several 

 pillar-like supports at the base; the top of the peduncle rapidly 

 expands, and gives rise to two or more large flabellate fronds, 

 disposed in the same plain, and more or less fused together basally. 



