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. . . . . / 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 striae 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 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 



