92 PLEIOCENE FOSSILS. 



growth; buccal margin obtusely rounded; anal margin more angular and somewhat com- 

 pressed ; umbones incurved, approximating. 



This shell resembles somewhat the Psammocola regia of Lea, found in the Meiocene 

 of Virginia; but is readily distinguished by its inequilateral form and less prominent 

 umbones. 



As it is common in the Pleiocene of South-Carolina, we have named it after that 

 formation. 



Plate XXII. Fig. 8, Natural size. 



Locality. Pee Dee; Waccamaw; Black River. 



Museum, College of Charleston. 



LAVIGNON.— Cuvier. 



The genus Lavignon commenced its existence in the Cretaceous period. 



LAVIGNON TELLINOIDES.— d'Orb. 



Plate XXIII. Fig. 1. 



Mactra tellinoides, Con., 'Jour. Acad. Nat. Sci., Vol. 6, p. 258, pi. 11, figs. 2, 3. 



Cumingia tellinoides, Con., Foss. Ter. For., p. 28, pi. 15, fig. 4. 



Lavignon tellinoides, d'Orb., Prod, de Paleontologie, Vol. 3, p, 101, No. 1891. 



L. testa ovata, tenui, fragili, striata; striis elevatis, concentricis, extremitate altera 

 rotundata, altera leviter cpmpressa, sub-acuta, dente laterali in una valva obsoleto. 



Description. Shell ovate, thin, fragile, with numerous raised concentric striee; one 

 end regularly rounded, the other slightly compressed and somewhat pointed at the 

 extremity ; lateral teeth distinct in one valve, in the other obsolete. 



Conrad says this shell inhabits the Northern Atlantic coast of the United States. 



Plate XXIII. Fig. 1, Interior and exterior of shell, natural size. 



Locality. Pee Dee. Museum, College of Charleston. 



