CARDITA. 



we do not know of any other Genus with which it may 

 he confounded, except it he Cardium, with which it agrees 

 in the regular ribs on the outside; hut the Cardium is 

 generally nearly equivalve, and besides two hinge teeth 

 in each valve, it has a distant lateral tooth on each side 

 of the umbo. 



Of the Lamarckian Cardita and Venericardia toge- 

 ther, there are a considerable number; those which he 

 has called Venericardia being all fossil except one. They 

 are all marine ; and when living, have a thin horny epi- 

 dermis. The fossil species occur in the newer formations 

 above the Chalk; several are found in the London Clay, 

 and Calcaire grossiere, as well as in the Crag* 



We have given in our plate the following species : 



Fig. 1 . Cardita calyculatus. 



2. the same showing the inside of both valves. 



3. " sulcatus. Chama autiquata, Linn. 



4. imbricatus. 



