MYA. GAPER. 
103 
Shell somewhat oval, rather convex, white, but mostly 
covered with a thick tough rust-colored skin, obscurely 
wrinkled transversely 3 inside white, glossy: the front mar¬ 
gin nearly straight: beaks obtuse, placed nearer to one 
end: hinge with two projecting teeth separated by a large 
triangular cavity, one of them erect, the other turning in¬ 
wards and sloping downwards: length about a quarter of 
an inch 3 breadth nearly half an inch. 
Belton sands, Scotland 3 and Dublin bay. v. m. 
13. Mya niteus. Glossy Gaper . 
Laskey, JVern. Soc. i. pi. S. f. 4. 
Shell oval, glossy white, growing pink towards the 
beaks, with regular concentric strias 3 inside colored in like 
manner, but not so glossy : beaks rather prominent, but not 
quite central: hinge with a single tooth in one valve, lock¬ 
ing into a deep cleft between two slight elevations in the 
other: length nearly a qnarter of an inch 3 breadth some¬ 
thing more. 
Dunbar, and Dublin bay: rare. v. m. 
14. Mya prismatica. Prismatic Gaper . 
Montagu, pi. 26. f. 3. 
Shell oblong-oval, But, thin, glossy .white reflecting pris¬ 
matic colors in various positions of light, rounded at one 
end and sloping to a point at the other, obscurely striate 
concentrically 3 inside smooth, glossy: beaks small, nearer . 
to and pointing towards the elongated end : hinge with a 
broad horizontal tooth, and an erect one, and .a somewhat 
triangular depression in both valves 3 in one valve is also a 
small lateral plate which is wanting in the other : length 
three eighths of an inch ; breadth as much again. 
On the Scotch coasts, and at Exmouth, v. v. 
15. Mya suhstrrata. Substriated Gaper . 
Montagu, Sitppl. p. 25. 
Shell somewhat oval, semitransparent, white, with ob¬ 
scure distant raised longitudinal lines 3 inside smooth, with 
a plain margin: beaks prominent, straight: hinge with. a . 
single projection inwards, margined so as to make it con¬ 
cave-. diameter the tenth of an inch. 
Devon coast, among Corallines : rare. 
16. Mya. 
