50 Mr. H. J. Carter on 



of one form onlj, viz. acerate, varying under 75 by 2|- 

 6000ths in. Structure loose, traversed plentifully by large 

 excretory canals which terminate in the vents mentioned. 

 Size of largest specimen, 3 inches high by 9 x 3 horizontally. 

 Depth 6 to 19 fath. 



2. AmorpMna nnjrocutis. 



Massive, flattish, sessile, irregularly lobed above, truncated 

 below. Consistence hard, elastic. Colour when fresh, 

 " nearly black," dark slate now. Surface very smooth, 

 covered with a minutely reticulated spiculo-fibrous dei-mis. 

 Pores in the interstices of the reticulation. Vents large, at 

 the ends of the mamilliform or prominent processes of the 

 upper part. Spicules of one form only, viz. acerate, but 

 of two sizes, following their situation, viz. : — 1, chiefly con- 

 fined to the body, 85 by H-6000th in. ; 2, chiefly confined to 

 the dermal, spiculo-fibrous reticulation, 25 to 30-6000ths long. 

 Structure commencing from without inwards with a tough 

 dermal coat about l-48th in. in thickness, contrasting strongly 

 in its dark colour with the lighter substance of the interior, 

 which is compact and traversed by the excretory canals that 

 end m the vents mentioned. Size 1\ in. high by 4x1^ 

 horizontally. 



Depth 7 fath. 



3. Amorphina cancellosa. (Diy specimen.) 



Massive, sessile, erect, lobed, somewhat compressed, con- 

 tracted towards the base. Consistence light, fragile. Colour 

 whitish grey now. Surface cellular, reticulated in relief; 

 interstices large, tympanized by sarcode charged with the 

 spicules of the species. Vents very numerous, plentifully 

 distributed over the surface generally, especially over the upper 

 part. Spicule of one form only, viz. acerate, of different 

 sizes, about 75 by 1^ -6000th in. Structure light, open and 

 cancellous throughout, almost flimsy from the great number 

 of large excretory canals with which the loose structure is 

 traversed, ending at the vents mentioned. Size of specimen, 

 which is very large (even in its dry state), 12 in. highbyl2x4^ 

 horizontally. Neither depth nor colour given. 



Group 3. T H A L Y S A. 



4. Thalysias massalis. 



Massive, sessile, elongated elliptically, truncate below. 

 Consistence soft. Colour, when fresh, " buff below, dark 

 maroon-red above," now light brown. Surface smooth, con- 



