56g 



Cardium cdule. Don. Br. Shells, iv. t. 124. f. 1.1. Edule, 



p. 76. 



Cardium ruRicum. Don. Br. ^Shells. W. t. 124. f. 2. Rusticum. 



This is another of this very intricate clafs that feems 

 to have puzzled the conchologift. It is faid to grow 

 to a larger fize, and to pofTefs fewer ribs than the edule, 

 and thofe more elevated ; but whether it is really diftinft 

 from that flliell, certainly admits of doubt. 



We lately received from a teftaceological friend, Mr. 

 SwAiNsoN, what he confiders as the riijlicitm, obferving, 

 that fuch were known by the name of RoJfcocJde, and 

 were fold for three pence per dozen, on the EJfex coaft, 

 when half a peck of the common fort fold only for one 

 penny : fuch are taken only on one particular fand off 

 Leigh, after flrong gales of wind. 



This fhell very well accords with that figured bv Don- 

 ovan, and is not unlike that given by Chemntitz, 

 which Gmelin quotes. If it is really diltincl from edule, 

 we fear no permanent character will be found, by which 

 it may be didinguilhed from the latter, as the number 

 of ribs vary. That the fmaller cockles are ufually defti- 

 tute of the rufous colour, and are more fub-orbicular, 

 muft be admitted ; the ribs are alfo finer; but are not 

 theie marks the effect of immaturity ? 



D d d d If 



