218 ARCA. AUK-SHELL. Class VI. 



9. TENUIS. Mo7it. Test. Br. Sup. 56. i. 2Q^ f. 1. 



* A. with a smooth subcordate shell, white with 

 an olivaceous epidermis ; beaks near one end 

 slightly inflected; greatest diameter a quarter 

 of an inch. 



Found on the shore near Dunbar. 



