]G4 BRITISH SPONGIADJ1. 



dispersed, also bihamate, simple or contort, large, few 

 in number. Skeleton fasciculi numerous, irregu- 

 larly disposed ; spicula subfusiformi-acuate, short and 

 stout. 



" Colour. Nut-brown in the dried state. 



"Habitat. Westport Bay, 6 7 fathoms, Ireland; 

 Rev. A. M. Norman. 



"Examined. In the dried state. 



"Among the specimens of British sponges dredged 

 in Westport Bay by the Rev. A. M. Norman and sent 

 to me for examination, there was a valve of Pecten 

 va-rius, on which there were two patches of sponges ; 

 one about an inch in length of Leuconia nivea, and 

 on the opposite side of the valve an incrustation 

 of a rough and rugged dark brown sponge an inch 

 and a half in length and not quite a quarter of an 

 inch in thickness, and this, on a careful microscopical 

 examination, proved to be a new species of Raphio- 

 desma, in many respects closely resembling in struc- 

 ture R. lingua. The surface does not resemble that of 

 R. lingua, and it has nothing of the tow-like appear- 

 ance of that sponge ; on the contrary, it is very rough 

 and rugged in appearance and of a dark brown colour. 

 In the forms of spicula of the dermis and the skeleton 

 the two species correspond to a very considerable 

 extent, and they also agree in their respective modes of 

 disposition in all parts of the sponges, but they differ 

 greatly in their proportions. Thus, although of nearly 

 the same form, those of the skeleton of R. lingua are 

 -^ inch in length and y^j inch in diameter, while 

 those of R. fallaciosum are only % inch in length and 

 YsVo mcn i n diameter ; and the same inequality of 

 size obtains in the retentive spicula of the rosette-like 



