HTMBNIACIDON. 79 



16. Htmbniaoidon perl^vis (Montagu,), u, 179; iir, 

 PI. XXXIV, figs. 1, 2. 



1867 Beniera perlxvis, Gray. Proc. Zool. Soc, p. 518. 



Habitat. — Bantry Bay (N.). 



17, Htmeniaoidon paohtdeema, Bow., ii, 184; in, 

 PL XXXIY, figs. 10, 11. 



1867 Beniera pachyderma, Gray. Proc. Zool. Soc, p. 518. 



18. HxMBNIAOIDOIf OEUSTULA, Bow., II, 185 J III, PI. 



XXXIY, figs. 3—6. 



1867 Beniera crusiula, Gray. Proc. Zool. Soc, p. 518. 



19. Htmeniacidon Hillibei, Bow.,n. sp.,iv, PI, III, figs. 

 1—3. 



" Sponge massive, sessile. Surface smooth and even, 

 Oscula simple, dispersed. Pores inconspicuous. Der- 

 mal membrane aspiculous. Skeleton dense, abun- 

 dantly spiculous. Spicula acuate, rarely subspinulate ; 

 closely felted together in all parts of the sponge, 

 Sarcode at the surface nearly black, opaque; inter^ 

 nally light coloured and semi-transparent, 



" Colour. — In the living state, dark brown, nearly 

 black. In the dried state, dark nut brown, 



" Habitat. — On oyster shells from the Ridge off 

 Dover ; James F, HiUier, Esq., of Ramsgate. 



