122 POPULAR CONCHOLOGY. 



or hatchet-shaped, inequivalve, and slightly 

 eared. A groove or pit in each valve, which 

 increases in size with age, and bears the liga- 

 ment; bosses unequal and distant, the lower 

 •valve rather convex, with the sides reflected 

 over, upper valve flattish. A large yellow bys- 

 sus. — Animal r , foot small. — 1 recent species. 



The only species known is found in the 

 Indian Seas, at great depths, and is rare. It is 

 white, slightly tinged with purple near the 

 bosses; and buries itself partially in madre- 

 pores, in crevices of its own boring. 



78. Lima. — Shell longitudinal, nearly equi- 

 valve, obliquely fan-shaped, slightly eared ; 



valves gaping near the bosses, which are dis- 

 tant ; hinge without teeth ; no byssus. A tri- 



