Calalogiie of Noii-Calcareous Sponges. 31 



ating styli, straight, gradually sharp-pointed and spined all over, 

 size about 0"1 by 0-0082 mm.;* (c) Dermal sj^icules, straight, 

 smooth, long and slender, varying in form from tylote to 

 tylostylote, with feebly-developed oval heads ; size about 0'25 by 

 0-003 mm. 



Microscleres, rather stout tridentate isochela?, of the usual 

 Myxilla pattern, about 0*025 mm. long. Very abundant. 



This species is evidently distinct from Carter's original Hali- 

 chondria pustulosa., as is clearly seen by reference to his description 

 and figures. 



R.N. 492 ("brick red"); 835; 844; 895; 922. All from 

 station 10. 



B.M. d. 97 1^'' Halichondna piistulata;' Reg. 87-7-11-26). 



Genus Alicrociona, Bowerljank (emended). 



Skeleton consisting of plumose columns. Megascleres all 

 monactinal, smooth and spined. Typical microscleres isoclielfe. 



Microciona scabida, Carter, sp. 



Halichondria scadida, Carter, A.M.N.H., February, 1885, 

 p. 112, pi. iv., tigs. 4, 5. 



Halichondria scabida, Carter, A.M.N. H., December, 1886, 

 p. 449. 



This species appears to come much nearer to Carter's original 

 " Halichondria pusiulosa " than does Alyxilla victoriana, which 

 he I'eferred to that species. 



R.N. 413 (x, 19 f; " orpiment-orange ") ; 1025 (x B) ; 1038 

 (X B). 



Genus Clathria^ Schmidt. 



Skeleton a reticulation of fibre, usually with much spongin, 

 coi-ed by smooth styli and echinated by spined styli. Typical 

 microscleres small palmate isochelse. 



I propose to drop the genus Rhaphidophlus of Ehlers, which 

 differs from Clathria only in the strongly-developed dermal crust 

 (if radiately-disposed styli. It is impossible to draw a sharp 

 distinction between the two. 



* The diameter given for spiued styli is always exclusive of the spiues. 



