22 ROYAL SOCIETY OF CANADA 
over 1 cent., diameter of stem nearly 2 mm., average diameter of the 
upper part, exclusive of the processes, about 4 mm., length of processes 
varying from 1 to 3 mm. This specimen is attached to a pebble; of the 
other two, one, with the stem missing, is 5 cent. long, the other has a 
total length of 23 mm. and its base firmly clasps three or four minute 
stones. 
Skeleton.—Compound of an axis of spiculo-fibre from which minor 
fibres, forming the axial part of the processes, are given off at right 
angles. 
Spicules.—(a) Megasclera; large, smooth, gradually and sharply 
pointed, smooth style, often narrowing toward the head, varying in 
length from ‘465 to ‘849 mm., with an average diameter of ‘013 mm. ; 
occurring in the main axial part with their pointed ends directed 
upward, and in the processes with the pointed ends outward.  (b) 
Microsclera; small palmate anisochele, with an average length of ‘022 
mm., abundant in the dermal membrane and throughout the sponge. 
Besides these two forms of spicules a third is present, one that is not 
mentioned by Fristedt in the description of his specimen and that 
might easily be overlooked on account of its inconspicuous size and 
shape. This spicule is a small, smooth, generally rather bluntly- 
pointed, either bent or straight, tylostylus, in length varying from ‘085 
to about ‘124 mm. and with a maximum thickness of ‘006 mm. ; it 
occurs in small numbers and is apparently distributed through the 
sponge. 
In the specimen already mentioned as being without a stem, the 
spicules are somewhat different in size to those of the other two; it is 
found that the styli are larger, reaching a length of 1:50 mm. with a 
thickness of :020 mm. and that the anisochelæ are smaller, having an 
average length of only ‘015 mm., beyond which there appear to be no 
structural differences of importance. 
Esperella Fristedtii differs from Æsperia cupressiformis, Carter, 
not only in not having the “ tricurvate ” spicule but also in the general 
form of the sponge including that of the processes, in the shape of the 
anisochele and in other points of dissimilarity that are apparent. 
Localities—In. Davis Strait, collected by A. M. Rodger. Cape 
Wild, bearing N.E. 10 miles, 200 fathoms, 4th of July, 1892; 3 miles 
from mouth of Coutts Inlet, 130 fathoms, 7th of July, 1892; E.S.E. of 
Erick Point, 20 miles, 60 to 100 fathoms, 4th of August, 1892. 

