Don Barclay asked for information on the Texas Eocene. This is a good
opportunity to publicize a great monograph by a gifted amateur:

Garvie, Christopher L., 1996, The molluscan macrofauna of the Reklaw
Formation, Marquez Member (Eocene: lower Claibornian), in Texas: Bulletins
of American Paleontology, v. 111, no. 352, 177 pp., 23 pl.

The publisher is:
Paleontological Research Institution
1259 Trumansburg Road
Ithaca, NY 14850 USA

--and you can order copies directly from their Web site.

Garvie's reference list includes many other works on the Eocene of Texas.
The Reklaw is not the only unit that contains shell beds, and I think it is
likely that your Leon County specimens come from a different Eocene unit.
But Garvie's monograph is a good place to start.

Another potential source of information is the Houston Paleontological
Society, which publishes guidebooks to Texas fossil faunas. Does anyone
have the address handy?

Andrew K. Rindsberg
Geological Survey of Alabama