39 
very thick, oval, inequilateral, gaping at both ends, 
coarsely wrinkled transversely ; beaks subcentral, from 
which two longitudinal ridges cross the shell like the 
letter V.; posteriorly a little rounded, anteriorly ob- 
liquely rounded, the edge imcurved: a single conic 
tooth and two muscular impressions ineach valve. 2+... 
3,5. Scarborough, rare. Much shorter in breadth 
than the Mya Glycimeris of Linneus, having rather the 
outline of Mya Truncata. 
TripeE.—MYARIA. 
Having a broad spoon-like tooth in each valve or in 
one only : gaping at one or both extremities. 
Grenus.—MYA. 
Transverse, gaping at both extremities, with one large 
dilated projecting and nearly vertical cardinal tooth 
in the left valve and with a hollow in the opposite 
valve ; ligament internal, short, thick, and inserted 
in the hollow of the primary tooth on the one side, 
and in the pit of the other valve. 
* Thereal Panopea Grycrmeris. (Mya. G. of Lin. 
—Don. t. 142.—P. Atprovann1, Lam. is still too 
doubtful a native to be at present inserted in our 
Catalogue. 
