REVISION " BRITISH SPONGIADJE." 203 



Quasillina brevis, B., XI. (Ridley and Dendy, 14, 

 p. 226; Vosmaer, 21, p. 20.) 

 Genus Halicnemia, Bowerbank. 

 Sponge symmetrical, flat discoid, with marginal fringe 

 of long spicules. Megascleres tylostyli. Microscleres (?) ; 

 spined centrotylotes. 



Note. I am not sure whether the small spined centro- 

 tylote spicules which Bowerbank describes in H. 

 patera (but no figures) are to be regarded as micros- 

 cleres. Yosmaer fused this genus with Polymastia, 

 but, as I think, without sufficient reason. Nor can, 

 according to Hansen (10, p. 8), Halicnemia be fused 

 with Badiella, as Marenzeller had done. 

 Halicnemia patera, B., XV. 



Genus Gliona, Grant. 

 Boring Suberitidse. Megascleres tylostyles. No mi- 

 crocleres. 



Gliona cela ta, Grant, XXXVIII and LXIV. (Hanitsch, 

 8, p. 216.) 



Family II. Tethyid^:, Vosmaer. 

 The ectosome is usually a well developed cortex with 

 distinct fibrous layer. Megascleres styli or tylostyli, 

 radially arranged. Microscleres, when present, spherasters 

 or microrrhabds. 



Note. I include under this family also the genus 

 Hymedesmia, B., as represented by H. stellata, B., 

 although this is a thin encrusting sponge without 

 cortex. An encrusting sponge very similar to H. 

 stellata, but possessing oxyasters instead of chiasters 

 was dredged last year in Liverpool Bay, for which I 

 propose the provisional name H. acuto -stellata. Its 

 spiculation, but not its mode of growth, reminds one 

 strongly of Axinella stuposa. Thus Hymedesmia 

 ought perhaps be included under the Axinellidae. 



