596 Canadian Record of Science. 
ently free. Walls thick, a cloacal depression at the sum- 
mit, which may be extended downwards as an open tube. The 
outer surface of the wall with circular canal apertures dis- 
posed in longitudinal rows. There are two series of canals ; 
a larger which traverses the walls in a generally vertical 
or oblique direction ; and a smaller which extends from the 
surface in an arched direction to the interior of the sponge 
wall. The skeleton consists of a connected spicular mesh- 
work, apparently of the Anomocladina type, in which there 
is a relatively small central node with a variable number of 
rays which connect with adjoining nodes. No distinctive 
dermal layer is present. 
The spicular structure of this genus is nearest allied to 
that of Astylospongia, F. Roemer, but the nodes are less de 
veloped, and the network is much less regular. Owing to 
the manner in which the spicules are replaced, and their 
coalescence, it is impossible to make a close comparison 
with other sponges, and, in fact, it is difficult to state posi- 
tively whether the spicules are uniformly of the Anomocla- 
dina type. The canal apertures of the surface, and the 
shape of the sponges as well, resemble some forms of Cala- 
thium, Bill., such as O. Anstedi’ and C. Fittoni,” but the spicu- 
lar structure in these latter is as yet unknown, and there- 
fore they cannot properly be compared with Steliella. 
STELIELLA BILLINGs!I, sp. n., pl. Figs. 1-4. 
Sponges subcylindrical or compressed so as to be nearly - 
elliptical in transverse section, or club-shaped ; the basal end 
obtusely rounded and apparently free. Thespecimens vary 
from 28 to 64 mm. in length, and from 14 to 34 mm. in 
thickness. The vertical rows of canal apertures are about 
1mm. apart, the apertures themselves, in the single 
specimen in which they are clearly shown, are circular or 
ovate and about 1 mm. in width. The larger canals, as 
shown in transverse sections, are from 0.5 to 1 mm. in 
width, those of the smaller series are from 0.2 to 0.3 mm, 
1 Pal. Fos., vol. 1. p. 210. 
2 Tb., p. 211. 
