1867.] DR- J. E. GRAY ON SPONGES. 551 



the rays. Spicules of ovisacs birotate ; rotulae crenated ; shaft spi- 

 nose, often rudimentary. 



1. DOSILIA PLUMOSA. B.M. 



Spongilla plmnosa, Carter, l. c. xii. p. 5, t. 1. f. 2; Bowerb. B. S. 

 f. 168-171, 208-212 ; P. Z. S. 1863, t. 38. f. 5. 

 Hab. Bombay. 



2. DOSILIA BAILEYI. 



Spongilla baileyi, Bowerb. P. Z. S. 1863, t. 38. f. 6. 

 Hab. United States, North America. 



See also Bowerb. B. S. f. 241. 



II. The ovisacs tessellated on the surface, armed with fusiform spi- 

 cules arranged parallel to and beneath the outer surface of 

 the sac; disk with a central boss or imperfectly developed 

 irregidar subbirotate spicules on the inner surface of the sac. 



3. Metania. 



Sponge ? Spicules fusiform, smooth, curved. Outer spicules 



of ovisac like those of the skeleton, smooth or spinulose. Spicules 

 of parietes birotate ; shaft short, smooth, or spiuose, stout ; rotulse 

 equal, subequal, or very unequal. 



* Shaft of birotate spicida smooth. 



1. Metania gregaria. 



Spongilla gregaria, Bowerb. B. S. f. 206, 213-216 ; P. Z. S. 1863, 

 t. 38. f. 7 (disk of ovisac-spines equal). 

 Hab. River Amazons. 



2. Metania paulata. 



Spongilla paulata, Bowerb. B, S. f. 221, 222. 

 Hab. Brazil. 



** Shaft of birotate spicida spiuose. 



3. Metania reticulata. 



Spongilla reticulata, Bowerb. ib. i. p. 38, f. 223, 322, 323 ; P. Z. S. 

 1863, t. 38. f. 9. 

 Hab. Brazil. ^ 



4. Acalle. 



Sponge- spicules fusiform, smooth. Ovisac-Sj)icules of outer sur- 

 face equibihamate, hooks four or five, recurved, large ; of wall 

 birotate, rotulae very unequal, inner one rudimentary, shaft very 

 slender. 



