Lorraine Faunas of New York and Quebec 
297 
vicinity of the beak, and with no indication of the mesial sinus. 
The hinge-line is gently and almost evenly curved downward 
posteriorly. A specimen of this type, associated with Catazyga 
headi, and Pholidops subtruncatus, occurs among a group of speci- 
mens labelled as coming from Chambly. No. 8431. 
30. Cyrtodonta clochensis, sp. nov. 
{Plate II, Figs. 6 A, B) 
Shell of medium size, obliquely ovate, widest posteriorly; height 
and length in the ratio of 17 or 18 mm. to 25 mm. with a convexity 
of 5 mm. in the type specimens, increasing to fully 6 mm. for the 
single valve in others of the same size. Beaks rather prominent, 
the umbones rising distinctly above the hinge-line; umbonal ridge 
rounded, but made more prominent by the flattening of the valves 
anterior to this ridge. In some specimens this flattening is accen- 
tuated to a slightly concave curvature extending obliquely back- 
ward f romthe anterior half of the umbones . Surface marked by fine 
concentric striae. Anterior muscular scar fairly large and rotund. 
The interior cast here figured exposed the presence of two subequal 
cardinal teeth which are nearly parallel to the upper anterior 
margin of the valve ; posteriorly there are casts of two long teeth 
which are subparallel to this margin of the valve. 
In outline this shell bears a considerable resemblance to Cyrto- 
donta janesvillensis. It is evident from the growth lines that the 
lower margin of the specimen here represented by Fig. 6B, on 
plate II, originally had the lower margin nearly straight for a 
distance farther to the rear than here figured, but the beaks and 
umbonal ridge appear to be much more prominent, and the 
greatest convexity of the anterior margin appears to be nearer the 
hinge-line. 
Locality. In the lower red clay shales of the Lowville bed 
along the western shore of La Cloche peninsula, a few feet above 
the railroad level. Collected in 1912 by Aug. F. Foerste, and pre- 
served in the Victoria Memorial Museum, at Ottawa, by the 
Geological Survey of Canada. Nos. 8410, 8410a. 
