534 DR. J. E. GRAY ON SPONGES. [May 9, 



** Flukes divided into several palmate hooks. 



5. Grapelia. 



Sponge ? Spicules inequianchorate, in circular groups ; tlie 



flukes divided into several unilateral palmate hooks. 



Grapelia australis, Bowerb. B. S. f. 135. 

 Hab. "West Australia. 



II. Defensive spicules unilateral bipolicated and inequianchorate, 

 free in the sarcode. 



6. Alebion. 



Sponge branching, anastomosing ; branches compressed, corym- 

 bose, rather hispid or parasitic. Spicules: — 1. Inequianchorate, 

 bidentate. 2. Needle-like, spined. 3. Cylindrical, slender, flexuous. 

 4. Equiancliorate, bipolicated. 



Alebion hyndmani. 



Halichondria hyndmani, Bovrerb. B. S. p. 264, f. 123-127. 



See also — 



1 Alebion 1 australis, Bowerb. ib. f. 131-134. 



Hab. West Australia. With tripolicated unilateral spines. 



7. loPHON. 



Sponge parasitic, smooth. Oscules dispersed. Skin spiculose. 

 Spicules: — 1. Fusiform, cylindrical, spined. 2. Simple, bipolicated, 

 anchorate. 3. Inequianchorate, dentate, palmate, and bidentate. 



1. lOPHON SCANDENS. 



Halichondria scanJens, Bowerb. B. S. ii. p. 2.")9. 



2. loPHON NIGRICANS. "^ 



Halicho7idria nigi-icans, Bowerb. ib. p. 266, f. 282. 



HI. Defensive spicules unilateral, equianchorate,free in the sarcode. 



* Flukes divided into two or three spines at each end. 



8. IsoDiCTYA, sp., Bowerb. B. S. i. p. 197. 



Sponge sessile, minutely hispid, regularly reticulated. Spicules of 

 tliree kinds: — 1. Needle-shaped, fusiform. 2. Bihamate, bicalca- 

 rate (Bowerb. f. 121). 3. Equiancliorate or palmate. 



IsoDiCTYA NORMANi, Bowerb. ib. ii. p. 320, f. 121, 376 (type). 



See also — 



Isodictya edwardsii, BoM'erb. ib. ]). 325. 



J. paupera, Bowerb. ib. p. 328. 



I. palinata, Bowerb. ib. ]>. 311. 



