ISODICTYA. 121. 



inches broad, and one and a half inch thick, with ten 

 large, elevated, oscular orifices, the largest nearly a 

 quarter of an inch in diameter. On the paper accom- 

 panying the specimen the colour is stated to be 

 ' lilac,' and Mr. Norman adds, * I have a specimen, 

 not so fine as regards oscula, &c., but twice the size 

 of this.' I am not surprised in so large a specimen at 

 the congregation of the oscula in large cloacal organs. 

 This frequently occurs in other largely- developed 

 species of sponge, which in a younger state have the 

 oscula simple and dispersed on the dermal surface. 

 In Halicliondria panicea these differences are of fre- 

 quent occurrence." 



17. ISODICTYA VARIANS, Bow., n, 281 ; in, 307, PI. 

 XLVIII, figs. 1416, PI. LXXXVIII. 



1867 Philotia varians, Gray. Proc. Zool. Soc., p. 522. 



18. ISODICTYA ELEGANS, Bow., n, 283 ; in, PI. XLIX, 

 figs. 1 5. 



Habitat. Under stones between tide-marks, "West- 

 port, Koundstone, and Birterbuy Bays ; also dredged 

 in these same bays growing on shells and ISTullipora 

 (K). 



19. ISODICTYA FALLAX, Bow., 11, 302 ; in, PI. LI, figs. 

 1013. 



