92 CONTRIBUTIONS 
O. lingua canis. Plate 3. Fig. 72. 
Two Views. 
Description. Shell elliptical, elevated and somewhat 
truncate at the dorsal and basal margins, convex, crenu- 
late on both sides of the beaks; margin raised between 
the beak and the base. 
Diam. eh Length 1.8, Breadth 1.1, of an inch. 
Observations. A single valve only of this curious species 
has come into my possession, and it is difficult to make 
out all its characters with certainty from it. The other 
valve may present important ones. The form of this 
valve, owing to the raised margin, resembles a dog’s tongue. 
On the exterior, along the edge of this elevated part, there 
is a slight fold, apparently as if it had been pushed up in 
a soft state. Very small radiating strie may be perceived 
near the beaks, and the whole surface is irregularly vari- 
cose. 
O. pincerna. Plate 3. Fig. 73. 
Two Views. 
Description. Shell orbicular, convex, flattened at the 
beaks, irregularly wrinkled ; substance of the shell thin, 
diaphanous ; beaks bent downwards ; margin sharp. 
Diam, 4, <1. Length .6, Breadth .6, of an inch. 
Observations. Although I have two valves and several 
pieces of this curious little shell, it is difficult to make out 
