CONCHYLIA— DirHYi?^. 8. 33 



Shell reaching to two inches and a half long, and four or five 

 broad : and is distinguished from the last species, by the anterior 

 end tapering to a rounded point, and by the tooth having a small 

 projection or denticle on one side. 



Mya testa ovatd, latere antico rotundato rejlexo, dente fastigiato Jiexu- ovalie. 



oso. 

 Shell oval, rounded and reflected at the anterior end, with the tooth 



flattened at the top and fiexuous. 

 Mus. nost. Dublin bay, at Clontarf. 



Shell three quarters of an inch long, and an inch and a half 

 broad, convex, yellowish-white, thin, striate transversely, obtusely 

 rounded at the anterior end, where the valves reflect a little : hinge 

 near the middle ; with the tooth of the left valve truncate at top, 

 running in a straight line, the anterior extremity curving inwards, 

 and the hinder extremity outwards, and without additional denticle. 



The specimen represented in our j)late, was dug up at Clontarf, a 

 few days previous to our leaving Ireland. It has the convexity of 

 the Mya truncata, with the rounded anterior end of the Mya aren- 

 aria, but not so much produced. The tooth is also very different 

 from either of them. 



