93 
MY A, Linn . Lamar eke, 
Gen. Char. A transverse bivalve,, gaping at botli 
extremities ; ligament internal : the left valve 
with a compressed rounded hinge toothy per- 
pendicular to the valve., to which the cartilage 
is attached. 
MY A mandibula. 
TAB. XLHI. 
Spec. Char. Gibbose. flattish in the middle, trans- 
versely undulated ; anterior side square, gaping’, 
•aperture oblong; posterior side straigbiish. 
The depth is about two-thirds the length; breadth half 
as much again as the length; the undulations are about 
twenty-five, following the margin; the beaks are incurved 
and pointed. 
In cutting the Canal at Devizes in Wiltshire, a variety 
of Micaceous Sandstone and Sand was found, in which 
many species of shells and shelly remains were concealed, 
and often only the forms of shells cast in the sand, cemented 
strongly enough, by compression, as it were, to hold to- 
gether, as here figured, the cast being distinct, and 
apparently very accurate. The species here figured is 
very like the recent My a truncata of Linn, but it gapes at 
