98 MYA. GAPER. 



smaller end where it gapes vrry much, strongly wrinkled 

 transversely, covered with a tough ochraceous skin, which 

 extends beyond the margin at the open end and forms a thin 

 membranaceous wrinkled tube, sometimes from six to nine 

 inches in length, dead white under the skin ; the valves 

 convex, and turning a little back at the open end ; inside 

 white : hinge with a broad thick obtuse erect tooth pro- 

 jecting forwards : length sometimes two inches and a half, 

 and three and a half broad. 

 At the mouths of rivers, v. v. 



2. Mya arenaria. Sand Gaper. 



Lister, p\. 41$. f. 262, and pi. 419. f. 263 Pennant, pi. 45 

 Donovan, pi. 85 Liun. Trans, vi. pi. 14. f. 3, 4 Dorset 

 Cat. pi. 4. f. 2 Wood, pi. 17. f. 3. 



Shell strong, oval, gaping and rounded at both ends, 

 but elongated and narrowed on one side, covered with a 

 thin yellowish or reddish-brown skin, sometimes marked 

 with dark patches, irregularly striate concentrically, with 

 often a faint appearance of longitudinal lines, sometimes a 

 little distorted or indented at the margin ; the narrow end 

 turning a little back, with a few hairs attached to the outer 

 skin 5 inside white, glossy j hinge near the larger enc! ; 

 the tooth thick, erect, and spoon-shaped, with a small la- 

 teral tooth-like projection from the anterior side : M 

 sometimes two inches and a half, and five in breadth. 



The younger shells are whitish, with an orange-yellow 

 band round the margin ; and when not more than half au 

 inch in length, are clear white and transparent. 



Under sand and gravel, v. v. 



3. Mya declivis. Sloping Gaper. 

 Wood,y\. 18. f. 3. 



?*iya praetemris. Pennant, pi. 50. f. 1. 



Shell oval, rather convex, very thin and brittle, semi- 

 transparent, white, smooth and somewhat polished, except 

 at the cartilage end which is a little roughened, rounded 

 at one end, somewhat truncate and angular and a little 

 gaping at the other, often a little contracted at the front 

 margin towards the truncated side, irregularly striate trans- 

 versely : beaks nearly central, forming a, roughened and 

 somewhat angular slope down the cartilage margin; inside 



vdrite 



