[lambe] sponges from THE ATLANTIC COAST OF CANADA 206 



face. The openings of the radial tubes on the gastral surface are about 

 0-068 mm. wide and fi*om 0-109 to 0-137 mm. apart fi'om centre to centre. 

 The thickness of the wall of the sponge decreases in thickness as tlie 

 osculum is approached. 



Spicules. — (1) Triradiatcs, of the tubar skeleton, with stout, gradu- 

 ally and sharply pointed rays ; basal ray up to 0'209 mm. in length ; the 

 lateral rays have an average length of Olll mm. ; thickness of rays at 

 base from 0-006 to 0-000 mm. (Plate III., tig. Qa). (2) Triradiates, of 

 the dermal surface, with two stout, straight, sharply pointed lateral rays 

 and a third ray equally stout, Avhicli is bent almost at right angles to the 

 direction of its basal part and which is curved slightl}' upward at its 

 outer end ; average length of bent ray 0-065 mm. ; average length of 

 lateral rays 0-111 mm. ; thickness of the three rays near the base from 

 0-006 to 0-009 mm. (Plate III., figs. 6b, 6c, 6d). (3) Quadriradiates, of the 

 gastral skeleton, with long, moderately straight, gradually and sharj)ly 

 pointed, rather slender facial rays and an apical ray of the same thick- 

 ness ; facial rays, about 0"131 mm. in length ; apical ray up to 0'085 mm. 

 long ; thickness of rays at base about 0-006 mm. (Plate III., fig. 6e). 



(4) Oxeote spicules ; stout, generally straight, rather abruptly but 

 sharply pointed ; up to 0-982 mm. by 0-019 mm. in size (Plate III., 

 fig. 6/). Very slender oxeote spicules, about 0*002 mm. thick, are associ- 

 ated with the stout ones ; their length has not been ascertained as. 

 on account of their extreme slenderness, they are generally broken. 



(5) Oscular spicules ; long, slender oxea, varying considerably in thick- 

 ness ; from 0-003 to 0*013 mm, thick and up to 4 mm. in length. 



Locdlity. — Eight miles southeast of Bonaventure Island, Gaspé, in 

 56 flithoms, stones and coarse sand, one specimen, in alcohol, J. F. White- 

 aves. 1872. 



Sycon asperum. (Sp. nov.) 



(Plate IL, figs. 8, 8^/, Sb, Sc.) 



The only specimen of this species in the collection is 10 mm. high 

 and 5 mm. broad ; it is narrowlj' oval in lateral outline and has an 

 oscular opening, about 1 mm. wide, situated in the vipper part and fringed 

 by comparatively short oxeote spicules. Colour in spirit, grayish-white. 

 Texture firm. Surface very rough. 



Skeleton. — Eadial tubes, about 0-109 mm. wide, lead from the dermal 

 to the gastral surface through the thin wall of the sponge which has a 

 maximum thickness of 005 mm. The outer surface presents an irregular 

 net-work of ridges between which are deep sunken areas ; in these areas 

 are to be seen the outer openings of the radial tubes. The gastral open- 

 ings of the tubes are closely but rather irregularly disjîosed over the even 

 inner surface of the wall ; they are from 0074 to 01 11 mm. wide. The 

 tubar skeleton is composed of triradiate spicules having the basal ray 



