New Species of Sponges. 63 
very seldom met with in the fossil condition, but it is not 
improbable that the delicate film of pyrites, seen in places 
on the surface of the Quebec sponges, may arise from the 
replacement of the flesh-spicules by this mineral. 
Sir J. W. Dawson has already classified and given pro- 
visional names to the Quebec sponges, and it will therefore 
be more convenient for me to refer to. their generic and 
specific details under these names. 
Genus, Protosponals, Salter. 
Protoepongia tetranema, Dawson. 
In the one specimen in which the outline of the sponge 
has been preserved, the body appears to have been elongat- 
ed oval, measuring about 45 mm. in length by 30 mm. in 
width. Very probably there was an aperture at the sum- 
mit, though it cannot now be distinguished. The wall of 
the sponge appears to have consisted—as in the other species 
of this genus—of a single layer of cruciform (?) spicules 
of various dimensions, disposed so as to form a framework 
with quadrate or oblong interspaces; the rays of the larger 
spicules constituting the boundaries of the larger squares, 
and within these, secondary and smaller squares are 
marked out by smaller spicules. Judging by the length of 
the rays of the larger spicules, the larger squares would 
be about 6 mm. in diameter, whilst the smallest do not ex- 
ceed 1 mm. The rays of the individual spicules slightly 
overlap, and it is probable that they may have been lightly 
cemented by silica at the points of contact. . The rays of 
the larger spicules are conical, gradually tapering from the 
central node to the blunted extremity; whilst the rays of 
the smaller spicules appear to be nearly cylindrical. 
From the base of the sponge, four slender elongated fili- 
form spicules project, They are approximately cylindrical, 
pointed at both ends, from .1 to.25 mm. in thickness, and 
from 50 to 70 mm. in length. Their proximal ends are in- 
serted apparently in the basal wall only of the sponge, and 
they project in the same direction, though not in lateral 
apposition with each other. In some specimens their dis- 
tal ends converge and appear as if united terminally, but 
this may be merely due to chance overlapping. 
