[LAMBE] SPONGES FROM COAST OF NORTHEASTERN CANADA 37 
length. The other rays, lying parallel to the gastral surface, of the same 
thickness as the apical ray but longer, curved slightly toward the gastral 
cavity, about “111 mm. in length. 
2. Gastral triradiates—With sharply pointed, straight rays, of 
about the same thickness as those of the quadriradiates and about ‘124 
mm. long. 
3. Subgastral triradiates—Sagittal, with rays coming to a sharp 
point and lying in the same plane. Basal ray straight, about :137 mm. 
long with a thickness of ‘006 mm., or a little more, at midlength, reach- 
ing well across the wall to the lateral rays of the subdermal triradiates. 
Lateral rays usually about -104 mm. long, curved slightly toward the 
basal ray, of the same thickness as the basal ray. 
4. Subdermal triradiates—Sagittal, with sharply pointed rays that 
do not lie in the same plane; basal ray straight, about ‘091 mm. long and 
‘006 mm. thick at midlength; lateral rays curved slightly toward the 
basal ray, about ‘072 mm. in length. Viewing the spicule from the side, 
the lateral rays make an angle of about 132° with the basal ray. In the 
skeleton this spicule has its basal ray parallel with the basal ray of the 
subgastral triradiates. 
5. Dermal triradiates.—Stout with tapering rays, about ‘085 mm. 
long, curved slightly inward. 
6. Stout ovea.—Straight and tapering to a sharp point proximally, 
curved in the outer half of their length and terminating abruptly in a 
minutely spined, more or less blunted, bent distal extremity. Deeply 
embedded in the wall at right angles to the dermal surface beyond which 
one-half or less of their length projects. Length averaging about ‘262 
mm. with a thickness at midlength of ‘014 mm. 
7. Linear spicules.—Very slender, hair-like, straight, about ‘098 
mm. long, at right angles to and projecting beyond the dermal surface. 
Locality —Strait of Belle Isle, off Norman’s Light, 60 fathoms, 
rocky bottom, A. M. Rodger, 9th of April, 1892, two specimens. 
The writer has much pleasure in naming this interesting species 
after Professor Thompson. 
