26 POST-PLEIOCENE FOSSILS. 



numerous somewhat obsolete radiating lines, which extend to basal margin ; the buccal 

 and anal sides are smooth, and without lines ; buccal margin round, curve continuous to 

 base of anal margin ; anal margin obliquely truncated ; interior of the shell profoundly 

 crenulated on the pallial margin only; serratures towards the anterior end large and 

 prominent ; the buccal and anal margins are without crenulations, and have thin edges. 



This shell resembles C. subline a.tum, Con., of the Pleiocene, but is readily distinguished 

 by being more ventricose, having the anal margin truncated, and the crenulations of the 

 pallial margin more profound. It is also a larger and a longer shell. But one valve has 

 yet been found in the Post-Pleiocene. It is not known to be living upon the coast of 

 South-Carolina, but dead shells (Post-Pleiocene fossils?) are sometimes found on the 

 beaches. For a long time we were doubtful about this shell, it being much larger than 

 C. serratum, of the Florida coasts; but I am now satisfied the size, and other minor 

 differences, are to be attributed to more favorable conditions for greater development which 

 existed during the Post-Pleiocene age. 



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



Locality. Abbapoola Creek. 



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



CAEDIUM MOETONI. 

 Plate V. Fig. 6. 



Cardium Mortoni, Con , Jour. Acad. Nat. Sci., Vol. 6, p. 259, pi. 11, figs. 5, 6, 7. 

 Cardium Mortoni, Gould, Invert. Mass., p. 91. 



Cardium Mortoni, DeKaij, Zool. New- York, Art. Mollusca, p. 207, pi. 23, fig. 251. 

 Cardium Mortoni, Stimpson, Shells New-England, p. 19. 



Description. Shell small, thin, sub-ovate, oblique, smooth, without ribs or radiating 

 striae. 



According to Conrad, Gould, and Stimpson, this small shell is common on the Northern 

 Atlantic coast of the United States. I have not yet found it on the Carolina coast, and it 

 is exceedingly rare in the Post-Pleiocene. 



Plate V. Fig. 6, Shell, natural size. This figure was accidentally blurred in the 

 printing. 



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



