44 Proceedings of the Royal Society of Victoria. 



Phwiohalichondria temdspiadata, u. sp. 



Sponge forming a thin crust, rising up into small, irregular, 

 branched, coralloid processes. Surface very uneven. Consistence 

 pretty firm and compact. Nearly white in spirit. 



Skeleton, very confused, consisting of very abundant slender 

 spicules, in great part scattered quite irregularly but often 

 collected into loose, whisp-like, irregularly-branching fibres, with 

 no obvious spongin. The axial portions of the fibres consist of 

 the slender oxea and they are irregularly echinated by the spined 

 styli. 



Meyascleres, (a) very slender, long, straight oxea, measuring 

 about 0-2 by 0-002 mm. ; (6) comparatively short, straight, spined 

 styli ; gradually and finely pointed, spined all over but most 

 abundantly at the base ; size about 0-08 by 0-004 mm.; (c) very 

 long and slender spined styli, gently curved and di'awn out 

 gradually into long fine points, the spines dying away towards 

 the apex; measuring up to about 0-25 by '0027 mm. Inter- 

 inediate forms of spined styli are also met with. 



The species is nearly related to r. purpurea, but differs in the 

 much more slender spicules and perhaps also in the external 

 form. There are no microscleres. 



R.X. 1024 (x B). 



Genus Ecliinodictyiun, Ridley. 



Skeleton usually reticulate. Megascleres smooth diactinal in 

 the fibre and spined monactinal echinating tlie fibre. Smooth 

 styli may also be present. No microscleres. 



Echinodictyuin ridlei/i, n. sp. 



Sponge lamellar to flattened digitate ; may be stipitate, pro- 

 liferous and bushy. Lamelhe usually thin. Vents small and 

 marginal. Surfaces usually smooth and glabrous. Texture 

 compressible, resilient, tough. Colour in spirit pale greyish 

 yellow. 



Skeleton, the m.ain skeleton is an iri-egular network of well- 

 developed horny fibre of pale colour, cored by numerous smooth 

 oxea in the main fibres. These spicules are commonly arranged 

 in a very loose, whispy manner ; they may be absent from some 



