PLATE VI. 



This is the largest of the Cardium, or Cockle genus, that inhabits 

 any of the British sliores. It is noted by Wallace as a Shell of the 

 Orkneys ; and also by Pennant, who likewise found it off the He- 

 brides. — It is a thick shell, with high radiated ribs, and beset with large 

 processes or spines that are hollowed. It Is covered with a fibrous 

 epidermis, of a blackish colour, varied with light browns ; the colour 

 beneath is white, with a faint tint of red, or rose colour. — Marginal 

 circumference ten inches and an half. 



This Is one of the six rare species Da Costa could not procure for 

 his work, and to which he alludes in the preface*. 



* I have described the shells from the objects themselves, except in six mitance:, where 

 I could not procure the originals to complete the series; in which case I have borrowed 

 them from authors of veracity; and the Reader will find those species distinguished by 

 Roman characters. 



