50 PLEIOCENE FOSSILS. 



PECTUNCULUS LiEVIS.— (New Species.) 

 Plate XVII. Fig 5. 



P. sub-ovali, crassa, incequilaterali concentrice striata vel sulcata; latere buccali rotundato; 

 latere anali sub-producto, oblique truncato; dentibus numerosis; labro crenato. 



Description. Somewhat oval, thick, inequilateral, concentrically striate, or grooved; 

 buccal margin rounded; anal side somewhat produced, obliquely truncate; lip crenato. 



The teeth extend without interruption around the hinge. The pallial and muscular 

 impressions are well defined, and in young individuals the shell is slightly angular near 

 the umbones. Umbones pointed and closely approximating. 



This is the only species of this genus, without radiating ribs, found in our newer 

 Tertiary rocks. 



Plate XVII. Fig. 5, Exterior of left, and interior, hinge and teeth of right valve. 



Locality. Waccamaw. 



PECTUNCULUS ARATUS.— Con. 

 Plate XVII. Figs. 6, Cm and 6i. 



Pectunculus aratus, Con., Am. Jour. Sci., Vol. 41, p. 346. 

 Pectunculus aratus, Con., Foss. Ter. For., p. 62, pi. 3, fig. 2. 



P. testa sub-ovali, sub-cequilaterali; costis elevatis; latere buccali truncato; dentibus cardi- 

 nalibus numerosis; labro crenato; area ligamenti striata. 



Description. Shell somewhat oval, nearly equilateral; ribs elevated; buccal side 

 truncate; cardinal teeth numerous, lips crenate. 



