262 The Ottawa Naturalist. [February 



lateral rays g^enerally slightly curved, about .091 mm. 

 long ; the three rays tapering to a point and about .009 

 mm. in diam.eter at midlength ; oral angle slightly small- 

 er than the other two. Thickly scattered irregularly in 

 the wall (figs, c and d). 



2. Gasiral triradiates. — Similar to the triradiates of the paren- 

 chyma except that the basal ray reaches a length of .209 

 mm., the lateral rays a length of .157 mm. and all the 

 rays are about .006 mm. in diameter at midlength. Lying 

 parallel to the gastral surface (figs, c and e). 



J. Dermal triradiates. — Slightly sagittal with equal angles, 

 the basal ray reaching a length of .072 mm., and the 

 lateral rays a length of .045 mm.; all the rays are round- 

 ed at their extremities and measure .004 mm. in diame- 

 ter ; an aborted fourth ray is sometimes apparently de- 

 veloped. Occurring in three or four layers parallel to 

 the dermal surface (figs. c. and f.) 



4. Large oxea. — Varying in length from .616 to 1.096mm. and 



in diameter at midlength from .041 to .068 mm.; slightly 

 curved, the curvature being most pronounced near their 

 outer ends ; at right angles to, and with generally about 

 one-third of their length projecting beyond, the dermal 

 surface. Some of the smaller spicules of this kind are 

 entirely embedded in the wall or protude but a little be- 

 yond the surface (figs, c, g and h). 



5. Minute linear spicules. — Very slender, about .131 mm. long 



and .002 mm. in diameter. Numerous and lying irregu- 

 larly, with the dermal triradiates, parallel to the outer 

 surface (figs, c and / ). 



6. Oxea of the oscular fringe. — Slender, about 2.5 mm. long 



and .09 mm. in diameter, forming a well developed fringe 



around the osculum. 

 Three specimens of this sponge were collected by the Rev. 

 George W. Taylor, of Nanaimo, B.C., who found them adhering 

 to the under side ot boulders, between tides, at Boat Harbour, six 

 miles south of Nanaimo, on the 24th of June, 1899. Mr. Taylor 

 has also sent to the writer two small sponges that on examination 



