3<j Proceedings of the Royal Society of Victoria. 



Megascleres, (a) smooth, straight styli, graduuUy sharp-pointed 

 at the apex, and evenly rounded at the base ; size aljout 0'2 by 

 0-0062 mm.; ((^) spined styli; usually straight, tapering gradu- 

 ally to a fine point, richly spined all over ; size about O'l by 

 0-005 mm. 



This remarkable species, characterised by the entire absence of 

 microscleres, should perhaps be considered as the type of a new 

 genus. As regards external form and the general arrangement 

 of the skeleton and the form of the megascleres it conies very 

 near to Clathria alata and C. myxilloides. 

 R.N. 376 (18 f ; "dull brown orange, yellower below"). 



Genus Ophtitaspongia, BowerV)ank* (emend.) 



Usually with strongly-developed horny filjre. INIegascleres 

 smooth styli, some of which echinate the horny fibre. Micros- 

 cleres may or may not be present. External form not 

 Jioneycombed. 



This genus, as thus constituted, will be a very useful one 

 diftering from Clathria in the smoothness of the echinating styli, 

 and from Echinoclathria in the external form. It has been 

 pointed out by Topsent that the first described species of 

 Clathria ( C. coralloides) has smooth echinating spicules, but 

 the genus was so imperfectly diagnosed by its author that we may 

 accept the views of subsequent writers, who seem to Ije agreed in 

 regarding- the spined styli as characteristic. This view leaves 

 the field open for Bowerbank's Ophlitaspo?igia, of which the 

 type has smooth echinating styli. 



Some species of the genus, in which the styli may be replaced 

 by oxea, form an interesting link between the Ectyoninaj and 

 Chalininie, and I have little doubt that my Siplwnochaliiia 

 /'ispiculata, described in the first part of this catalogue, I'eally 

 l)elongs near here. 



Ophlitaspongia subhispida, Carter, sp. 



Echinoclath?-ia sitl'hispida, Carter, A.ISt.N.H., November, 1865, 

 p. 356. 



* Monograph of Bi'itish Sponges, Vol.. II., p. 14. 



