HexactinellicUe and Lithistidee. 463 



scription, to be quite sufficient to show that it is a distinct 

 species. 



Farrea densa, n. sp. (PL XVII. figs. 5 & 6.) 



Skeleton composed of lattice-like, subrectangular, thickly 

 spined, vitreous fibre, varying in size with its age, anastomosing 

 freely in all directions, so as to form a densely reticulate 

 massive structure. Fibre originally based on sexradiate 

 spicules, whose forms have become more or less recognizable 

 by the process of absorption above mentioned ; thickly spini- 

 ferous, each spine conical and divided at the summit into 

 several spinules, which are expanded (fig. 6, bhb). 



Hab. Marine. 



Loc. Seychelles. 



Obs. There are many large detrital fragments of the deci- 

 duous skeleton of this sponge mixed up with those of Farrea 

 occa, and a host of other matters, all entangled in the tuft of 

 anchoring-spicules at the base of Dr. A. Farre's specimen of 

 Fuplectella cucumer ; but none appear to indicate the general 

 form of the sponge to which they belonged, while they are 

 accompanied by such a variety of minute spicules of all kinds 

 that it is impossible to state which, if any of them, formed part 

 of their original structure. 



Among the spicules boiled off from these minute fragments 

 and mounted in balsam, as before stated, may be observed: — 

 a new form of equianchorate, very large, with both ends of 

 the shaft winged or spread out laterally by a thin expansion 

 like that on the shaft of the anchorate in the deep-sea sponge 

 called by the late Dr. M. Sars " CladorMza abyssicola " 

 ('Remarkable Forms of Animal Life from the Great Deeps on 

 the Norwegian Coast,' by the late Dr. M. Sars, edited by his 

 son, p. 65, pi. vi. f. 32 : Christiana, 1872) ; several kinds of 

 bihamate spicules, among which is one sparsely spined on the 

 body and measuring 23 1800ths of an inch long by one 1800th 

 of an inch in its thickest part (this is the largest known, being 

 more than twice the size of that in the deep-sea sponge just 

 mentioned, viz. CladorMza abyssicola, which with another 

 similar sponge, viz. Chondrocladia vtrgata^Vy. Thomson, were 

 abundantly dredged up on board H.M.S. ' Porcupine ') ; three 

 distinct forms of siliceous globules, indicating as many species 

 of Geodia ; one discoid from Stelletta mammillaris, Sdt. (?) ; 

 the scopuline shaft oiAphrocallistes beatrix in great abundance ; 

 spicules of undescribed species of Gumminea3, especially that 

 figured by Dr. Bowerbank (P. Z. S. 1869, pi. iii. figs. 6 a & 16) 

 as belonging to " Dactylocalyx pumteeus, Stutchbury " ! the 

 surface-spicule of two different kinds of Lithistidae, and frag- 



Ann. & Mag. N. H. Ser. 4. Vol. xii. 32 



