222 Mr. W. 8. Kent on two new Siliceous Sponges. 
résumé of the two new genera and species here introduced; 
each of these latter standing at present as the sole representa- 
tive of its genus, the characters embodying the genus will also 
inclusive of the species. 
Subclass PORIFERA SILICEA, J.E. Gray. 
Order ARMATOSPONGLE, 45. 
Fam. Esperiadz, ib. 
Gen. nov. RHAPHIDOTHECA. 
Sponge incrusting, cavernous interiorly; entire external sur- 
face of cortex bristling with spinulate spicula having their 
attenuate apices directed inwards and mingling freely with 
the fascicles of simple acerate spicula which form upright 
supporting pillars to the roof; fascicles of smaller acerate 
spicula abundant in the sarcode of the cortex, and also dis- 
tributed less frequently in the basal layer of sarcode, and in 
that investing the shafts or pillars; in the latter, also, 
minute spicula of the ^ palmato-inequianchorate” type 
(Bowbk.). Oscula absent or indefinite. 
R. Marshall-Hallit, ib. Pl. XV. figs. 1-7. 
Hab. A depth of 500 fathoms ten miles off the shore of 
Cezimbra, Portugal; attached to Lophohelia prolifera. 
Order CORALLIOSPONGLGE, J. E. Gray. 
Gen. nov. FIELDINGIA. 
. 
diminutive spicula of the “ rectangulated hexradiate” type; 
these also minutely and erectly spined. Nutritive and ex- 
halant functions most probably performed through the ge- 
neral reticulations of the cortex. 
F. lagettoides, ib. Pl. XV. figs. 8-15. 
Habitat and associations similar to the last. 
nutely and erectly spined ; frequently attached to them very 
i i ‘rectan 
