274 THE DEVONIAN. FOSSILS OF CANADA WEST. 
only for those which have the foramen concealed, but also for those 
with it open. It appears probable that the genus will sooner or later 
be sub-divided, and in that case Athyris might be retained for the 
species with closely incurved beak, and Spirigera for some of the 
others. 1 shall give some account of the generic characters of this 
group of shells in another article. "The following species are placed 
in the genus provisionally. 
Arnyris Crars.—WN., Sp. 
tI 
; AZ 
Ay 
ey) \ 
Z Y y) y , 
Zs Lj, vi y 
inl i 
A fey Ze YY 
ti Mh . Hi ii We 
= 
g 
Se 
4 i 
We 
Fig. 31. 
Fig. 29. Athyris Clara—-Ventral view of large specimen. 
Fig. 30.—Dorsal view of the same. 
Fig. 31.—Side view. 
Fig. 32.—Dorsal view of a smaller specimen. 
Deseription.—Nearly smooth, ovate or sub-rhomboidal, greatest 
width, about the middle, a short linguiform projection in the middle 
of the front margin, both valves convex, ventral valve the larger, with 
