58 PLEIOCENE FOSSILS. 



Description. Shell convex, inequilateral, radiately ribbed; anal margin short; buccal 

 margin somewhat produced. 



The radiating ribs are sometimes bifurcated ; lines of growth prominent on the disks ; 

 beaks contracted and prominent. 



The compressed and oblique form of this shell, together with the small but well-defined 

 radiating ribs, distinguish it from its congeners. 



This species is found living along the coast of North and South Carolina; nor is it very 

 uncommon in the Meiocene of Virginia. 



Plate XVIII. Fig. 6, Interior of right valve. 

 " 7, Exterior of left valve. 



Locality. Darlington District. 



Museum, College of Charleston. 



LUCINA C E I B R A RIA.-S > r. 

 Plate XVIII. Fi<;s. S and 9. 



Lucina cribraria, Say, Jour. Ac, Nat. Sci., Vol. 4, p. 147, pi. 13, fig. 1. 

 Lucina cribraria, Con., Foss. Ter. For. pi. 3, fig. 1. 



L. testa orbiculata, convexa, radiation tenuiter costata, eoncentrice elevato-lamellosa; latere 

 anali flexuoso ; lunula sub-impressa. 



Description. Shell orbicular, convex, radiately and finely ribbed; with concentric 

 elevated lamellse; anal side flexuose; lunule somewhat impressed. 



This common species is distinguished by the rather distant, prominent lamellse on the 

 umbones, which become more numerous and closer towards the pallial margin, giving that 

 part of the shell a decussated appearance. 



