of the Nalional Anlarctic Expedition. 287 



Surface level, or almost irapercojjtibly liispid ; sliowing 

 tlirougli the dermal membrane a somewhat areolated pattern, 

 each areola being formed by the end of a main fibre giving 

 off fimbriated twigs which roof over the subdermal spaces 

 between the main fibres. A few circular oscules about 

 5 mm. in diameter, and with slightly raised rims, occur. 



Skeleton formed of longitudinal lines of fUit, loose, band- 

 like main fibres, witii an irrer^ular and obscure reticulation of 

 single spicules between. The main fibres spread out in a 

 paniculate manner a little below the dermal membrane. 



Spicules. — Megascleres : oxeas 537 X 16*25 /x, slightly bent 

 or curved at centio, attenuating gradually to sliar[) points. 



Sigmata varying in size, the largest being -AO ft long, 

 ll'G fi broad, and 1"76/a thick, with one or more angular 

 bends in the curve, usually one end of the shaft with an 

 angular bend, the other end curved. 



The specimen selected as the type of this species has a 

 flattened angular pad-like body, 10 cm. long, 4'5 cm. broad, 

 and 2'5 cm. thick; it apparently lay free on the bottom. 



An "areola" with its central node (the end of the main 

 fibre) and lateral branchlets occupies on an average an area 

 of 6 x4 mm. 



The upper surface alone shows the areolated appearance 

 below the dermal membrane, the under surface being nearly 

 opaque. 



The triangular cushion-like sliape of the type calls to 

 mind Gelliufi Jhci/eilifer (K. & D.), but there are no flagellate 

 sigmata in the new species. G. rudis (Topsent) has a much 

 firmer and denser structure, the oxeas are shorter, thicker, 

 and with tornote ends, and the sigmata are more slender and 

 with unitorm curve. 



The ends of the main fibres aro arranged in linear series. 



The dermal membrane is separated about 3 mm. from the 

 floors of the large subdermal spaces, and the band-like 

 supporting pillars are about 2 mm. broad. A vertical section 

 gives the appearance of a miniature " hall of a thousand 

 columns." The dermal membrane on the under surface of 

 the sponge contains scattered oxeas arranged tangentially. 



Localities. \V inter Quarters, 12-20 fath. ; Coulman I., 

 100 fath. 



Gellius pilosuSj sp. n. 



Sponge in form of an erect flattened triangular or elongate 

 lamella divided or digitate at the up[)er edge. Consistence 

 soft, fleshy, compressible. 



Colour \\\ s|)irit dirty white or very [lale yellow. 



