24 POST-PLEIOCENE FOSSILS. 



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 speci- 

 mens, the crenulations on the ribs, on the buccal side, are not always prominent, but after 

 they attain to the 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. — T. 4- H. 



Cardium magnum is a common recent shell on the coast ; is rare as fossil in the Pleio- 

 cene, but abundant in the Post-Pleiocene. 



Plate V. Fig. 2, Exterior andinterior of valves, 7iatural size. 

 " 2a, Side view of shell. 



Locality. Simmons'. Museum, College of Charleston; Cabitiet F. S. H. 



CARDIUM M U R I C A T U M . — L I N N . 

 Plate V. Fig. 3. 



Cardium muricatum. Linn, Syst. Nat., p. 1123. 



Cardium muricatum. Lam., Vol. 6, p. 398. 



Cardium muricatum. Conch. Icon., pi. 6, fig. 33. 



Cardium muricatum, Chem?i., 6, pi. 17, fig. 177. 



Cardium muricatum, Ency. Meth., pi. 297, fig. 1. 



Cardium muricatum. Lister, Conch., pi. 322, fig. 159. 



Cardium muricatum, Ravenel, Cat. Coll. Shells, p. 5. 



Cardium muricatum, De Kay, Zool. New-York, Art. Mollusca, p. 207. 



Cardium muricatum, L. R. Gihhes, Tuomey's Geol. of So. Ca., appendix, p. xxi. 



Cardium muricatum, Tuomey Sf Holmes, Pleiocene Foss. So. Ca., p. 64. 



Description. Shell large, cordately ovate, somewhat oblique, radiately ribbed ; ribs 

 convex, muricated with minute, compressed, obliquely arranged tubercles. On the buccal 

 side of the shell, the tubercles are on the anterior side of the ribs ; these are followed by a 

 few ribs which are muricated on both sides ; and on the anal side the tubercles are turned 

 backwards.— T. Sf H. 



Living on the coast of South-Carolina and rarely found fossil in the Pleiocene or Post- 

 Pleiocene formations. 



Plate V. Fig. 3, Exterior of valve, natural size. 



Locality. Simmons'. Museum, College of Charleston; Cabinet F. S. H. 



