68 RECORDS OF THE AUSTRALIAN MUSEUM. 



Renirra corticata, sp. nov. 

 (Plate X., fig. 2). 



This species exhibits two marked forms, simulating in this 

 respect Ualichondria panicea, Johnston. One is lobulate and 

 consists of six or more erect lobes, which arise from a short 

 peduncle ; the lobes anastomose here and there, tapering above 

 and below the middle; the surfaces exhibit a few rounded eleva- 

 tions. Each lobe has a large central tube, which commences at 

 the base and terminates in a circular aperture at the summit ; 

 their diameter varies from 5 to 10 mm. The walls of the tubes 

 are regularly perforated with oscula-like openings about 1 or 2 mm. 

 in diameter. The dermal membrane is fine, very close, and renieroid 

 in texture ; in water-worn examples the subdermal surface exhibits 

 numerous round or oval pores, these are uniformly distributed and 

 generally under 1 mm. in diameter. 



The other form is flabellately expanded, and consists of two or 

 more lamella?, with prominent oscula scattered over the surface 

 and along the semicircular margin ; their diameter rarely exceeds 

 3 mm. The texture in the dry state is hard and scarcely com- 

 pressible ; when wet very soft and elastic. There is a distinct 

 cortical layer, about 1 mm. in thickness, it is tough and often 

 remains intact after the inner ground substance has been washed 

 out. Sections of well preserved specimens exhibit a much larger 

 proportion of spongin in the cortex than in the ground substance. 



Skeleton consisting of a number of more or less distinct main 

 fibres, two or three spicules wide, which curve outwards from the 

 centre to the surface ; these are united by unispicular secondaries, 

 with generally a triangular mesh. Spicules slightly curved and 

 gradually sharp-pointed oxea. Size about Oil by 0006 mm. 

 Colour grayish brown or light stone. 



Two specimens from Tuggerah Beach. 



This species would naturally fall into the genus Pellina, 

 Schmidt." 



Halichondria, Fleming. 



Halichondria panicea, Johnston. 



Halichondria panicea, Johnston, Brit. Sponges, 1888, p. 114, pi. 

 xi., fig. 5 ; Bowerbank, Mon, Brit. Sponges, i., p. 278, pi. 

 xix., fig. 303; Bowerbank, ib., pp. 97-99, pi. xxxix., pl.xl.; 

 Ridley and Dendy, Chall. Rep., Zool., xx., 1887, p. 2, pi. ii., 

 figs. 2-3 (spicules). 



A single much worn example of this species is present in the 

 collection from Tuggerah Beach. The length of the larger oxeote 

 spicules is about 0*7 mm. 



1* See remarks on the genus by Eidley and Dandy — Chall. Eep., Zool., 

 XX., p. 15. 



