C A R D I A D M . 25 



CARDIUM ISOCAEDIA. 



Plate V. Fig. 4. 



Cardium isocardia, Linn., Syst. Nat., p. 1122. 



Cardium isocardia, Chemn., 6, p. 182. 



Cardium isocardia, Wood, Conch., p. 217. 



Cardium isocardia, Lam., An. sans Vert., p. 398. 



Cardium isocardia, Wood, Index Testaceologicus, pi. 5, fig. 15. 



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



Cardium isocardia, L. R. Gibbes, Tuomey's Geol. So. Ca., appendix, p. xxi. 



Cardium isocardia, Adams, Gen. Recent Shells, Vol. 2, p. 455. 



Description. Shell obliquely cordate, inequilateral, ventricose, imbricated ; anal margin 

 coarsely serrated or notched ; ribs thirty to thirty-five, imbricated, sub-fornicated. 



Like Cardium serratum, this shell, when compared with living specimens, presents 

 characters very much modified by the influences of the conditions of the age in which it 

 lived. I find dead and water-worn shells, on our sea beaches, which to our mind are 

 undoubtedly Post-Pleiocene fossils; the animal does not exist on the Carolina coast, but 

 inhabits the West India seas and Gulf of Mexico. 



What is considered a curious incident may be here alluded to ; of twenty-six or 

 eight specimens found, there is not a single right-hand valve. 



Plate V. Fig. 5, Exterior of valve, natural size. 



Locality. Abbapoola; Folly Island; and Simmons'. 



Museum, College of Charleston; Cabinet F. S. H. 



Genus, L M V I C A RD I U M.— S w a i n s o n. 



LJ1VICAEDIUM SEEEATUM. 



Plate V. Fig. 5. 



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



Cardium serratum, Chemn., 6, pi. 18, fig. 189. 



Cardium lsevigatum, Lamk., An. sans Vert., Vol. 6, p. 403. 



Lsevicardium serratum, Adams, Gen. Recent Shells, Vol. 2, p. 457. 



Description. Shell thin, smooth, obliquely ovate, inequilateral, ventricose, with 

 7 



