CONCHYLI A— D/T/fFi?^. 23. 7I 



being so much produced at one end : but they gradually run into 

 each other, and may be readily known from all the species of this 

 division, by the regular transverse striae, which grow gradually 

 fainter and disappear towards the hinge. 



M ACTBA testa oblongd depressd ineequilaterali, latere producto rotun- jeaurata. 



dato altera subtruncato, umbonibus iucurvis. ' ^• 



Shell oblong flattish inequilateral, rounded at the elongated side and 



somewhat truncate at the other, with the beaks incurved. 

 Tab. nost. 5, g. 8. 

 Mus. nost. Dredged up in the offing of Exmouth. 



Shell five-eighths of an inch long, and an inch and a quarter 

 broad, opake and strong } one side elongated, sloping from the beaks, 

 and rounded ; the other shorter and somewhat angular, where it is a 

 little open : color dull greyish-white, covered with a shining bronzed 

 skin reflecting metallic lustres ; coarsely and irregularly striate 

 transversely, with a few coarser ridges towards the hinge : inside 

 glossy greyish -white, with the margin plain: beaks rather promi- 

 nent and pointed, a little inclining to the longer side. 



Of this very beautiful shell we know neither description nor 

 figure. In the outline it something resembles the Mactra deal-bata 

 described in the eighth vol. of the Linnean Transactions, p. 68, tab. 

 1, fig. 10, and the Dorset Catalogue, tab. 7, fig. 7. But that shell 

 is represented as thin and transparent, and somewhat angular at the 

 longer side: the teeth also ajjpear to be different. 



