57 
MYA? angustata. 
TAB. DXXXI.—fig. 1. 
Spec. Cuar. Valves unequal; transversely elon- 
gated, thin, antiquated, irregularly compressed ; 
extremities obtuse, gaping; lower edge of 
the lesser (right) valve concave. 
Two or even sometimes three times as wide as long, 
uneven, and sometimes curved ; the umbones are much 
nearest to the anterior extremity; they are small, and 
not eroded: the hinge resembles those of Myz plana 
and subangulata, tab. 76; but that it belongs to the same 
genus asythe Mya labiosa is doubtful. 
Newly discovered by Professor Sedgwick in Colville 
Bay, Isle of Wight, along with Mytili, Ostree, and some 
shells sometimes referred to fresh water, in a bed of 
Sand and Clay evidently belonging to that mixture ge- 
nerally called the Upper Marine Formation. 
