68 I5EITISH SPONGIAD^. 



10. Htmedesmia simpltcissima. Bow., hi, 253 ; PL 

 LXXX, fig. 1. 



11. Htmedesmia tenuicula, Boio., n. sp., iv, PI. I, fig. 5. 



" Sponge coating, very thin. Surface even, smootli. 

 Oscula sinaple, minute, dispersed. Pores inconspi- 

 cuous. Skeleton fasciculi variable, flat; spicula few 

 or very numerous in each, bases and apices coinci- 

 dent, attenuato-spinulate, long, slender, minute, 

 variable in size. 



" Colour. — Alive, deep blue ; in spirit, light blue. 



" Habitat. — Roundstone Bay, Connemara, Ireland ; 

 Eev. A. M. Norman. 



" Examined. — From spirit. 



" Among the specimens of Irish sponges that I re- 

 ceived for examination from the Eev. A. M. Norman 

 there were two small fragments of granite, the largest 

 being seven lines in length by four lines in breadth, 

 and the smaller one being not half the size of the 

 largest. On each of these there were minute patches 

 of a dull, pale blue colour as taken from the spirit, but 

 which, from the label on the bottle, were of a deep 

 blue colour when alive. The thickness of the sponge 

 does not exceed that of a sheet of writing paper. 

 "When a portion of the sponge was mounted for 

 microscopical examination with a power of 100 linear, 

 scarcely any of the spicula were visible amidst the 

 sarcode, which presented a strongly gelatinous appear- 

 ance in the water; but when mounted in Canada 

 balsam they became completely visible. The struc- 

 tures of the sponge are very simple ; one form of 



