PLEIOCENE FOSSILS. 



95 



AMPHIDESMA JIQUATA.-Cos. 

 Plate XXIII. Fig. 5. 



Amphidesma sequata, Con., Proceed. Acad. Nat. Sci., Vol. 1, p. 307. 

 Amphidesma aequata, Con., Foss. Ter. For., p. 65, pi. 36, fig. 5, 

 Amphidesma aequata, d'Orb., Prod, de Paleontologie, Vol. 3, p. 101, No. 1887. 



A. testa in longitudinem ovali, convexa, striis 17 lamellosis concentricisque instructa; 

 umbonibus sub-prominentibus. 



Description. Shell longitudinally oval, convex, with about 17 laminated concentric 

 striae; buccal and anal margins nearly equally rounded; pallial margin regularly rounded; 

 beaks slightly prominent. 



This species is rare in the Pleiocene of South-Carolina; the numerous laminated con- 

 centric striae are very characteristic. 



Plate XXIII. Fig. 5, Imperfect shell, natural size. 



Locality. Pee Dee. • Museum, College of Charleston. 



DONAX.— Linn. 



The genus Donax commenced its existence in the seas of the Eocene period. 



DONAX VARIABILIS. — Say. 



Plate XXIII. Fig. 6. 



Donax variabilis, Say, Jour. Acad. Nat. Sci., Vol. 2, p. 305. 



D. testa triangulari, striis inconspicuis, longitudinalibus, parallelis, equalibus, impressis; 

 margine buccali oblique truncata, cordata, sutura sub-convexa; margine anali sublineari, 

 sutura dentata; margine palliali media paulo prominente, intus crenulata. 

 25 



