Sponges from the Atlnndr Ocean. 231 



tation, which is only observed in the (hy specimens, indicates 

 that, as usual, the accuniulation of the foreign objects is 

 confined to tlie lines of the subjacent, in this instance sub- 

 corneous, dermal reticulated structure. 



On the 2J)th March last the Rev. A. M. Norman sent me 

 another species of this genus, for which he proposes the 

 sj)eciHc name of " iiirru,s(ans.^^ It only differs from that 

 above described in the papilla? of the surface not being so 

 j)rominent and thorny, and in its structure being areolar and 

 sandy tliroui/Ziout like that of D^m'dea fragiUs, and of 

 a light yellow instead of a ])ink cream-colour when dry. 

 Loc. " Shetland, 170 fathoms,^' on iiard objects. 



Spongia orfficinalis. (PL XII. fig. 1,*^^) 



General form unequally lobate, sj)roading, sessile. Colour 

 light brown. Surface irregularly lobed and minutely divided 

 into polygonal spaces by the dermal horny reticulation, which 

 supports and thus siiows itself through the transparent dermal 

 sarcode, projecting from tlie latter at the knots or points of 

 union of the lines respectively in attenuated, minute, horny 

 filaments, which give the surface a hairy appearance. Pores 

 in the interstices of the dermal reticulation. Vents large and 

 irregular both in size and situation. Internally consisting of 

 a densely reticulate, anastomosing, horny, transparent, tough, 

 brownish fibre, which gives the brown colour to the sponge ; 

 supporting transparent areolar sarcode, which is traversed by 

 the excretory canal-system, often running in a branched form 

 for some distance just below the dermal sarcode before opening 

 at the vents mentioned. Size li inch in its largest diameter. 



Ilah. Marine, on hard objects. 



Loc. Same as that of Ap/gsina ncevns, viz. station 65. 



Obs. This, which is a genuine specimen, although small, of 

 Spongia officinalis, is only found in the jar numbered 65^ 

 where it has partly overgrown the upper valve of the same 

 Terebratule as that on which Aplysina ncevus has spread 

 itself (fig. I, d), presenting between them a small portion of 

 Dgsidea fragilis (fig. 1, e). 



While the Terebratule bears the three sponges just men- 

 tioned, it is itself fixed to a pebble (fig. 1, a) which bears 

 in addition two small specimens o{ Phnl- cilia infunclibulifonnis, 

 Johnst. (fig. Ijfty), also the basal fragment of a cylindrical 

 calcareous worm-tube over which LairuncuUa ci'atera, Bocage, 

 has grown (fig. 1, gg), and at the foot of this on the pebble 

 a little patch of Micmciona longispicidum, n. sp. (fig. 1,^); so 

 that the pebble and the Terebratule together bear six species 



k;* 



