Eocene Fossils of the United States. 403 
L. impressa, Lea; Cont. to Geol., plate i, fig. 30, Dec. 1833. 
Its varieties epprdach so near to diioss of the preceding species, 
that it may not be really distinct. It is usually less ventricose 
and less elevated and more distinctly folded. In some specimens 
the posterior fold is profound. 
Luctna Mopesta. Orbicular, ventricose, thin, with minute ap- 
proximate concentric lines; posterior side with an impressed sub- 
marginal fold ; posterior margin truncated, direct ; ligament margin 
straight and Bitiane: beaks prominent, medial. (Plate IV, fig. 13.) 
Claiborne, Alabama. Rare. 
Livcina susvexa. Suborbicular, profoundly ventricose, with 
fine concentric and minute obscure radiating lines ; posterior side 
with a fold consisting of two furrows, the submarginal one ob- 
scure; radiating lines minute and obscure; anterior margin ele- 
vated and angulated at the extremity of the hinge line; anterior 
side with an obsolete fold; posterior margin érintakael direct ; 
umbo ventricose; beaks died al; hinge narrow, edentalous; 
within secfoundly punctate. (Plate IV, fig. 14.) 
Lucina subvera, Con. ; Foss. Shells of 'Tert. Fon es 
Claiborne, Alabama. 
A rare ‘species. I have but one valve, whidhea is thin about thie a 
, thicker above, with a rough unequal nimean 
tate interiors the lunule small and impressed, and eet a 
narrow and. without teeth. 
¥ - 
Explanation of the Plates. 
Prate Iil. Fig. 7. T. papyria. 
Fig. 1. Crassatella alta. : pei 
2. C. protexta. oe 
10. T. alta. 
C. aleformis. 
Outlines of immature shell! 
of C. protexta. 
11. Corbis undata. 
12, Lucina alveata. 
13. L. modesta. 
ae 
5. C. rhomboidea. BE 8 wade 
Puiate IV. 15. L. carinifera. 
Fig. 1. Crassatella palmula. 16. Corbis lamellosa. 
2. Amphidesma linosa. 17. Lucina pomilia. 
3. Corbula oniscus. Ce 
4. C. nasuta. ’ 
5. Amphidesma tellinula. Fig, 1. Tellina Raveneli. 
6. Tellina plana. 
