190 Scientific Proceedings, /Royal Dublin Society. 



P. anancora, sp. n. — Sponge small, spherical, depressed, oscule 

 single. Spicules — (1) acerate, 1'68 by 0*023 mm., to 3*18 by 

 0*023 mm. ; (2) fork, shaft, 1*63 by 0-0276 mm. ; arms, simple, 

 0*127 mm. long ; (3) chiaster as usual. 



Habitat.— Bahia. 7-20 fms. 



P. gigas, sp. n. — Sponge massive ; several large oscules on the 

 upper surface. Spicules — (1) and (2), 3-18 by 0-024 mm. ; acerate, 

 1-7 by 0-039 mm. ; (3) fork, shaft, 1-96 by 0-039 mm. ; arms, 

 0*223 mm. long; (4) chiaster, capitate rays, 0*013 mm. in dia- 

 meter. 



Habitat.— St. Paul's Eocks. 



P. tenuispicula. — Sponge small, oscule single. Spicules — 

 (1) acerate, 1-35 to 2*3, by 0-016 mm. ; (2) fork, shaft, 1*6 by 

 0-016 mm. ; arms, 0*12 mm. long ; (3) chiaster; rays not capitate, 

 0-012 mm. in diameter. 



Habitat. — Bermuda, W. Indies. 



P. pachydermia, sp. n.— Sponge massive, lobate, free, two or 

 more oscules on the upper surface ; cortex very thick. Spicules — 

 (1) acerate, 1-193 by 0-0178 mm. ; (2) fork, shaft, 1*114 by 

 0*022 mm. ; arms, simple, - 12 mm. long ; (3) anchor, shaft, 1*35 

 by 0-0158 mm. ; rays, 0*067 mm. long ; (4) chiaster, rays abruptly 

 truncate, but not capiate, 0-006 to 0*011 mm. in diameter; colour, 

 purplish. 



Habitat.— Tahiti. 30-70 fms. 



P. crassispicula, sp. n. — Sponge irregularly spherical; free; 

 oscule single. Spicules — (1) acerate, 3*5 by 0*024 mm., and 2*3 

 by 0*052 mm. ; (2) fork, shaft, 2*36 by 0*08 mm. ; arms, 0*254 mm. 

 long; (3) chiaster, rays capitate; from 0*012 to 0*02 mm. in 

 diameter. 



Habitat. — Bahia. 7 to 20 fms. 



P. purpurea, Eidley. 



P. longancora, sp. n. — Sponge small ; a single circular oscule, 

 having the margin fringed by minute acerates projecting radiately 

 in the plane of the apertures. Spicules— (1) acerate, 1*63 by 



