46 Proceedings of the Royal Society of Victoria. 



Ecldnodictyuin arenomim, n. sp. 



Massive, depressed, spreading. Upper surface even, almost 

 flat, with meandriniform sandy pattern and minutely-reticulate 

 dermal membrane between. Vents minute, scattered. Incom- 

 pressible, intensely sandy and friable, with radiately columnar 

 structure, due to the arrangement of the sandy tracts. Colour 

 in spirit pale grey and sandy. 



Skeleton, composed chiefly of sand arranged in dense tracts as 

 above described. Between these sandy tracts are scattered 

 numerous slender tylostrongyla or tylota, without definite 

 arrangement except towards the surface, where very loose, 

 whisp-like fibres terminate in a dense layer of short, I'adiating 

 tufts wdiich support a small-meshed reticulate dermal .skeleton 

 of abundant tangentially-placed tylostrongyla or tylota. The 

 sand grains in the interior of the sponge are sparsely echinated 

 by spined styli. 



Megascleres, (a) tylostrongyla ; straight or slightly curved, 

 slender, with very slightly-developed head at one end and bluntly 

 rounded ofl" at the other, or with a small head at each end 

 (tylote) ; measuring about 0-19 by 0-003 mm. ; (6) spined styli 

 or tylostyli ; straight, slender, minutely spined all over, gradually 

 and finely pointed ; size about 0'0S3 by 0-003 mm. ; scarce. 



Ji.J. 925 (s. 1). 



Genus Jiaspailia, Nardo. 



Sponge usually consisting of long slender branches ; with a 

 dense central axis of spiculo-tibre containing much spongin, from 

 which loose tufts of spicules radiate to the surface. Smooth 

 monactinal (sometimes diactinal) megascleres are present, and 

 also spined echinating styli*. No microscleres. 



I agree with Topsent in removing this genus from the 

 Axinellidai to the EctyoniniH, although it is certainly intei'- 

 mediate in structure between these two groups. 



Raspailia pinnatiflda, Carter, sp. 



Dictyocylindnis pinnaiijidus, Carter, A.M.N.H., Novendjei-, 

 1885, p. 353. 



* Often extremely rare and hard to detect, perliaps sometimes absent. 



