of the National Antarctic Expedition. 277 



Lipocilla ai)pareiitly of the typical form j the present two 

 species both have spathuhite bipocilla with crenulated ends ; 

 and, further, tliere are differences, viz. in the shape of the 

 body, the arrangement of the skeleton, and the character of 

 the ectosomal spicules, which lead me to regard the 

 ' Discovery ' specimens as belonginp^ to distinct species. 



Localities. Winter Quarters, 25-30 fath.; Ooulman I., 

 100 fath. 



lophon jlabello-digitatus, sp. n. 



Sponge forming a large palmato-digitate or digitate growth 

 in one plane ; branches compressed, usually with oscules 

 along one edge. Surface finely verruculate ; witli elongated 

 pore-areas supported by fan-like wisps of ectosomal spicules. 



Colour dark brown ; consistence soft, the sponge being 

 readily broken. 



Skeleton typically formed of a network of spiculo-fibre, the 

 primary lines of which proceed upwards and outwards from 

 the inner surface of oscular tubes to the outer surface of the 

 sponge, where their ends form the vernic;c ; the secondary 

 fibres join the primary at right angles, forming rectangular 

 meshes about 1*25 mm. square. The tliickness of the primary 

 fibres is about •? mm., that of the secondary about 'O mm. 



The ectosomal skeleton consists of fan-like bundles and 

 wisps of spicules, isolated or proceeding upwards and spreading 

 out from the terminal main fibres. 



Spicules. — Mogascleres : smooth styles, 590 x25 fx,, curved, 

 with a mucro at the head end. 



Ectosomal spicules, 344 X 12*5 /tA,subamphitylote, fusiform, 

 with a marginal ring of vertical spines at both ends and a 

 terminal central spike at one extremity. 



Microscleres : palmate anisochelte of two sizes, a large 

 kind 35 /j, long and lO'T fj, broad, with thick shaft, with 

 triangular palmate tooth, 17-5 yu. long, at the large end, not 

 quite as long nor as broad as the ahe; lower margin of aUe 

 convex. Lower central tooth with a curved upper edge 

 produced into a spine, 



A small kind, 11-5 /n long, Q-2 fi broad; upper palmate 

 tooth triangular, rounded above, as broad and as long as the 

 a\x ; lower border of alte concave ; lower tooth with simple 

 rounded upper edge. 



Bij)ociUa varying in length from 55 to 11 /a, according to 

 the convexity of tiie shaft, which is usually deeply curved ; 

 both ends spathulate, nearly similar, and with crcnulatc 

 edges, or with 5-7 teeth. 



