116 • LAWEENCE M. LAMBE ON 



smooth. Dermal membrane moderately thin, fragile, very easily separated from the under- 

 lying portions of the sponge. Oscula large, conspicuous, about 3'5 mm. in average diameter ; 

 each opening is situated at the summit of one of the rounded protuberances. No pores have 

 been observed. Of this species there are four specimens, preserved in alcohol, the largest of 

 which is about 105 mm. long, 56 mm. broad and 23 mm. high in its thickest part. 



Skeleton. — (a) Dermal ; a beautiful network of spicules (oxea) lying in and strengthening 

 the dermal membrane, {h) Main ; consisting of an irregular reticulation of fibres having an 

 average breadth of 0-108 mm. and made up of many spicules lying side by side with a very 

 small proportion of horny matter. 



Spicules. — (a) Megasclera ; short, stout, slightly curved, abruptly and sharply pointed 

 smooth oxea (Plate II., fig. 2a), from 0-144 to 0-176 mm. long and 0-013 mm. broad, forming 

 the principal part of the skeleton. (6) Microsclera ; smooth toxa (Plate IL, figs. 2b-e), 

 sharply pointed at both ends and of varying curvature, about 0-111 mm. long, measured in a 

 straight line from point to point and 0-002 mm. thick ; these spicules do not occur in large 

 numbers and seem to be confined exclusively to the main skeleton, very few having been 

 observed in the dermal membrane. 



Locality. — Kyska Harbour. 



Tedania fragilis. (Sp. nov.) 

 (Plate IL, figs. 3, 3 a— c.) 



This species is represented in the collection by a single dried specimen in the form of an 

 irregular flat mass about 50 mm. across and 15 mm. thick. Colour, brownish-yellow. 

 Texture, very fragile, crumbling. Surface, rough. Dermal monbrane, very thin, delicate. 



Skeleton. — {a) Main, consisting of an indefinite reticulation of loose strands of stylote 

 spicules, inclosing triangular and quadrangular meshes having sides generally of one spicule's 

 length, with many loose styli and tylota throughout, (i) Dermal. The dermal skeleton is 

 made up of tylota lying in the plane of the dermal membrane ; the tylota occur scattered 

 about Avithout order, but show a tendency in places to form loose fibres and to converge 

 toward a central point over the subdermal cavities. The interior of the sponge is very open 

 in its stucture, and has small canals leading through it in all directions. 



Spicules. — (") Megasclera, of two kinds. (1) Stout, slightly bent, smooth styli, evenly 

 rounded at one end and coming aliruptly to a sharp point at the other (Plate IL, fig 3), 

 varying in size from 0-314 by 0-011 mm. to 0-406 by 0-016 mm. ; occurring in the main 

 skeleton. (2) Straight, slender tylota with slightly inflated spined ends, generally termi- 

 nating in a sharp point, but often rounded (Plate IL, figs. 3a, 3b), from 0-229 to 0-262 mm. 

 long and 0-006 mm. thick ; present in large numbers at the surface and scattered throughout 

 the main skeleton. (6) Microsclera; long, minutely spined rhaphides, pointed at each end 

 and generally curved or twisted (Plate IL, fig. 3c) ; average size, 0-275 by 0-003 mm. ; 

 abundant throughout all parts of the sponge. 



Localities. — Amaknak Island (Dall) ; Sooke, Vancouver Island (J. Macoun). 



ESPERELLA LINGUA, BoW. 



Hymeniaeidon lingua, Bow. ISlifi. Mon. Brit. Spong., vol. ii., p. 187. 

 Raphiodesma lingua, Bow. 1874. Mon. Brit. Spong., vol. iii., p. 237, pi. Ixxii., figs. 1-6. 



E!<peria lingua, Vosmaer. 1885. The sponges of the " Willem Barents" Expedition, 1880 and 1881, p. 30, pi. i., 

 fig. 17, pi. iv., figs. 21, 22, and pi. v., figs. 73-77. 



