<?ARDIUM. 245 



SMOOTH-KEELED HEART COCKLE. 

 PI. 59./. 3, 4. Mr. Jennings. 



54. Cardium humanum. C. testa cordata, valvulis compressis, carinis 



Itevis, umbonibus approximatis. 

 Shell heart-shaped, valves compressed, keel smooth, beaks close together. 

 List. Conch, pi. 219. f. 158. Knorr Vergn. 6. pi. 11. f. 1. Born Test. 



pi. 2. f. 15, 16. Chem. Conch. 6. pi. 14. f. 145, 146. Encyclop. 



Method, pi. 294. f. 1 . a. b. 



This shell has been considered by Linnaeus, and some 

 subsequent authors, as a variety only of the preceding ; 

 but we are disposed to agree with Chemnitz, who has 

 distinguished it specifically on account of its margin, 

 which is always smooth, and its colour, which generally 

 consists of red spots, disposed in a quincunx order, 

 upon a white ground. 



Inhabits the same country as the preceding, but is 

 more rare. 



The beautiful shell, from which our figure was co- 

 loured, formerly belonged to Dr. G. Fordyce, who re- 

 fused fifty guineas for it. This shell is now in the pos- 

 session of Mr. Jennings, to whose liberality the Author 

 is greatly indebted for the use of many rare and valuable 

 specimens. 



The C. monstrosum of Chemnitz, 6. pi. 14. f. 140, 150. 

 bears too strongly the character of an accidental dif- 

 formity to be noticed as distinct, till more have been 

 found of the same shape. 



Gmelin's variety & of C. medium, p. 3246, must be re- 

 rejected ; it is the C. donaciforme, quite a distinct shell. 



