Catalogue of Non-Calcareous Sponges. 35 



distinguished by a very tliin wing-like expansion or fimbria along- 

 each side of the shaft.* Length about 0*022 mm. 



Ji.iY. 752 (s. 5; "light orange-brown"); 763 (s. 1); 792 

 (Sorrento Jetty; "greyish-brown"); 801 (s. 1 ; "orange-brown"); 

 842 (s. 10); 843 (s. 10). 



Clathria //lyxiiloides, n. sp. 



Massive, depressed, cake-like. Surface rather uneven ; villous 

 with projecting fil>res, although the dermal skeleton appears to be 

 intact. Compact, soft, resilient. Pale greyish-yellow in spirit. 



Skeleton, the main skeleton is a very loose and irregular net- 

 work of stout, whisp-like, nuiltispicular fibres, mostly running 

 towards the surface. The fibres appear very lax and with 

 little or no obvious spongin. They are made up of the smooth 

 styli, irregularly echinated and accompanied by the spined styli. 

 Between the fibres loose megascleres are abundantly scattered. 

 The dermal skeleton consists of dense, radiating tufts of smooth 

 styli. 



Megascleres, {a) long, straight, slender, smooth styli ; evenly 

 rounded at one end and sharply pointed at the other ; about 0-3 

 by 0-0042 mm.; (b) spined styli; straight and rather slender, 

 gradually sharp-pointed and abundantly spined all over ; about 

 0-13 by 0-005 mm. 



Microscleres, tridentate isochelte, resembling those of Myxilla, 

 with strongly-curved shaft. Length about 0-025 mm. 



This species at first sight closely resembles Clathria alata but 

 differs in the form of the spicules very considerably. 



R.N. 729 (s, 5). 



Clathria imperfecta., n. sp. 



Sponge compressed, cake-like, crumbling. 



Skeleton, a very irregular reticulation of loose, whisp-like, 

 multispicular fibre without obvious spongin, irregularly echinated 

 and accompanied by spined styli, but composed principally of 

 smooth styli. Many spicules are scattered between the fibres, 

 especially spined styli, and at the surface thei-e is a poorly- 

 developed dermal skeleton of loose radially-disposed smooth styli. 



* Wlieiice the name of the species. 



