DENDY NON-CALCAREOUS SPONGES 127 



Very numerous. (4) Slender or fairly stout, more or less contort sigmata (Figs. 

 6d, Qd') ; with short, strongly recurved, finely "pointed ends ; measuring commonly 

 about 0-033 mm. from bend to bend. Much smaller sigmata also occur (Fig. Qe), which 

 may belong to a different category. 



Register Numbers, Localities, &c. IV. 12, 16, 20, dredged off S.W. coast of Beyt 

 Island; X., XXXIV. 11, channel, W. side of S. end of Beyt Island, 3-4 fathoms, 

 3.1.06; XVIII. 3, channel, W. of Beyt Island, 3-4 fathoms, Jan. 1906; XXXIII. 6, 

 Dhed Mora and adjacent rocky ground between Beyt and Aramra, 1 fathom, 21.12.05. 



38. Chondropsis kirkii (Carter). 



Dysidea kirkii Carter [1885]. 

 ? Sigmatella australis Lendenfeld [1889]. 

 Sigmatella corticata Lendenfeld [1889]. 

 Chondropsis kirkii Dendy [1895]. 



I identify with this species a single well preserved specimen which differs in no 

 important respect from the common Australian form. The specimen is subdigitate, 

 consisting of two or three tubular processes partially fused together side by side and each 

 terminating in a conspicuous but constricted vent, surrounded by a membranous collar. 

 The surface is slightly conulose, minutely reticulate where rubbed, sub-glabrous where 

 uninjured. The texture is rather soft and compressible, the colour in spirit pale grey. 

 Height of specimen 31 mm., breadth 36 mm., diameter of digitiform processes about 

 12 mm. 



The main skeleton consists of the usual irregular reticulation of fine-grained sand- 

 fibre. The dermal sand- reticulation is less strongly developed than is usual in Australian 

 specimens. The spicules are the usual slender strongyla and small sigmata, the 

 strongyla perhaps rather better developed than in most Australian specimens. 



Previously known Distribution. Australian Seas (Carter, Lendenfeld, Dendy). 



Register Number, Locality, &c. IV. 11, dredged off S.W. coast of Beyt Island. 



39. Myxilla arenaria Dendy [1905]. 



I identify with this species three specimens in the collection, all from about the same 

 locality. The one (R.N. IV. 2 a) upon which the following notes are based is irregularly 

 and massively lobose, slightly clathrous, about 66 mm. in height and 50 mm. in greatest 

 breadth. It looks (in spirit) like a mass of sand held together by pale grey, gelatinous 

 " sarcode," which forms a thicker or thinner surface layer. The surface is uneven and 

 slightly conulose or rugose. The vents are rather small and arranged in a row on the 

 prominent ridges which form the top of the sponge. 



The skeleton is composed chiefly of a dense agglomeration of coarse sand-grains 

 which, to the naked eye, show, through the translucent dermal membrane, a distinct 

 tendency to be arranged in ascending columns. These sand-grains are very sparsely 



I 2 



