PLEIOCENE FOSSILS. 63 



CARDIAM. 



CARDIUM.— Bruguiere. 



CARDIUM M A G N U M . — B o r n. 

 Plate XIX. Fig. 1. 



Cardium Magnum, Bom., Test. Mus. Coes. Vind, pi. 3, fig. 5. 

 Cardium Maculatum, Gmelin, Conch. Icon., pi. 4, fig. 20. 

 Cardium Ventricosum, Bruguiere, Lam., Vol. 6, p. 400. 



C. testa maxima, ventricosa, oblique cor data, latere anali sub-angidato-depresso, radiatim 

 costato; costis planulatis, buccalis crenulatis. 



Description. Shell very large, inflated, obliquely cordate; anal side somewhat angu- 

 larly depressed; radiately ribbed, ribs flattened, buccal ribs crenulated. 



This shell presents some variation in form ; some individuals are more ventricose, whilst 

 others present a greater disproportion between the length and height. 



In young specimens, the crenulations on the ribs on the buccal side are not always 

 prominent, but after they attain to a height of an inch or two they appear and are very 

 persistent. The buccal ribs are somewhat angular, with the angles turned towards the 

 anal side. 



The specimen figured might easily be confounded with C. laqueatum, Con., of the 

 Meiocene of Virginia; but the very regular flat crenulations on the buccal ribs in 

 C. magnum will serve to distinguish the two. 



Although this is one of the most common recent shells of the coast, and is very abund- 

 ant in the Post Pleiocene, it is quite rare in our Tertiary beds. The single valve figured, 

 and the fragment of a full-grown individual, are all that have hitherto been found. 



Plate XIX. Fig. 1. 



Locality. Darlington District. 



Museum, College of Charleston. 



17 



