ENTOMOLOGY. 



To define the distinction of this shell from any of those peculiar 

 to Europe, and which are found in the seas surrounding our coasts, 

 it may be observed that it is as large as the ordinary growth of 

 Cardium Echinatum, or rather more than one third of Cardium 

 Aculeatum ; it has the contour of the former very exactly, but the 

 ribs are far more numerous, amounting to forty seven in number, 

 while in C. Echinatum they scarcely exceed eighteen, or in Aculeatum 

 about twenty ; the ribs are neither raised into acute ridges, nor 

 beset with spinous processes ; they are only slightly elevated, 

 roundedj and somewhat rough with obsolete recurvate transverse 

 imbrications, as in the Common Cockle, Cardium Edulis. Cardium 

 laevigatum, when very young, may be considered as one of the most 

 thin and fragile of the British species of this family, but these are 

 scarcely thinner in that early state of growth than our Cardium 

 Rackettii when it has attained the full dimensions of the example 

 represented in the annexed plate. The outline of Cardium Laevi- 

 gatum, it may be added, also is much more elongated and oblique, 

 or cuneatedj and it may be unnecessary to pursue the comparison 

 further, since there is still less accordance between the other British 

 species and our present shell than is observable in those we have 

 already mentioned. 



This new species of Cardium was received last year from New 

 South Wales, where it was found with many other interesting 

 objects now in our possession by Mr. Humphrey, resident in that 

 colony. 



