78 AMERICAN JOURNAL 



C. viRaiNiCA, Conrad. 



Descriptio7i. — Ovate, thick, inclined to be subfalcate ; apex 

 laterally curved ; margin about the apex thickened, striated ; 

 inner plate long, margin sinuous. 



O. fornicata, Conrad, not Say. 



Locality. — Virginia. Miocene. 



Very variable from profoundly ventricose to slightly convex. 

 In large specimens the margin behind the apex is very thick. 

 Length two inches. 



C. RECURVIROSTRA, Conrad. 



Description. — Obliquely suboval, profoundly ventricose, pos- 

 terior side obliquely depressed ; anterior side contracted and 

 slightly grooved below the apex, which is subspiral and recurved, 

 but not detached ; margin of internal plate sinuous. 



Local. — N. C. ? Miocene. 



PERSICULA, Schura. 

 P. OVULA, Conrad. Miocene Fossils, pi. 49, fig. 9. 



Description. — Ovate, short, shoulder acutely rounded ; callus 

 of labium distinct, subangular, and continued round the upper 

 margin of aperture ; mouth rather narrow, slightly widest at 

 base ; submargin of labrum minutely crenulated within ; plaits 

 eight, upper ones minute, penultimate plait very large. 



Locality. — James River, Virginia. 



MARGINELLA, Lam. 



Marginella constricta, Emmons. 



This Miocene species, bearing the same specific name as a very 

 different Eocene species previously described, I propose to name 

 Marginella contracta. 



M. constricta, Emmons, Geol. of N. C, fig. 135. 



Having formerly used the name of Porcellana, Adanson, it is 

 necessary to remark, in explanation of my having adopted La- 

 marck's generic name, that the former having been given by 

 Rumphius to Cyprcea, Lin., obliges us to restore Marginella. 



The genus LJrato, Risso, has not been found in the United 

 States, and therefore the shells I referred to it must be restored 

 to Marginella. 



The subgenera of 3fargi?iella cannot successfully be applied 

 to the Eocene species. Marginella larvata would be a Persicula 

 if it had not an external margin to the larbrum. So would M. 

 crassilabra., Conrad, judging by the numerous plaits on the 

 columella alone, but it has a raised spire and very thick margin 

 of labrum. M. constricta, Conrad, has five plaits. 



