274 THE DEVONIAN FOSSILS OF CANADA WEST. 
may belong to the same species, but more specimens are required to 
determine this point. 
Locality and formation.—Corniferous Limestone, County of Haldi- 
mand. 
Collector.—J. De Cew. 
Remarks on the genus Charionella. 
A silicified fragment of the dorsal valve of C. Circe a 
little enlarged, shewing the absence of a regular hinge- 
plate. 
A fragment of the ventral valve of O. seitula ? shewing 
the deltidium and muscular impressions in part. 
By treating partially silicified specimens of this genus 
with acids, I have ascertained that the structure of the 
hinge-plate differs from that of Spirigera in being either 
obsolete along the middle or anchylosed to the bottom of the valve. 
In Athyris = (Meristella, Hall) there is a well developed hinge-plate, 
supported beneath by a strong mesial septum, which extends some- 
times nearly to the front of the valve. In Charionella there is either 
no mesial septum, or, one that is merely rudimentary. In one 
specimen there is a remarkable partition, which runs obliquely from 
near the beak to the margin near the front. It completely divides 
the internal cayity into two parts. This I believe to be not a mesial 
septum, but a temporary wall formed by disease of the animal, be- 
cause both spires are crowded into the smaller of the two cavities, 
the larger being empty. 
It is probable that further researches will bring to light other char- 
_ acters of the hinge-plate in other species, and I do not therefore con- 
fine the genus to such as have this organ constructed exactly as in 
C. Circe and C. seitula. 
The species figured by De Verneuil under the names of Zerebratula, 
Schulzii, TP. Bordii, and T. mucronata, in the Bulletin of the Geolo- 
gical Society of France, 2nd Series, Vol. VII., Plate 3., have the 
aspect of this genus, and exhibit the same structure of the beak, 
foramen and deltidium of the ventral valve, and most probably have 
the same internal organization. 
(To be continued.) 
