ABSTRACT
The known fauna of the Midway of the western Gulf province includes, roughly, 47 genera of Pelecypoda, 2 of Scaphopoda, 65 of Gastropoda, 1 of Cephalopoda, and 1 genus of Vermes that has been commonly referred to the Gastropoda. For the purpose of determining the relationships of this Paleocene fauna to those which precede and follow, the genera may be segregated into more or less clearly defined assemblages: (1) genera recorded in the Midway that have persisted from the Cretaceous to Recent time; (2) those restricted to the Cretaceous and Paleocene; (3) those restricted to the Cretaceous and early Tertiary; (4) those restricted, at least in the Gulf province, to the Paleocene and early Eocene; (5) those restricted to the Paleocene and Eocene; (6) those restricted to the Paleocene, Eocene, and Oligocene; (7) those initiated in the Paleocene and continuing to the Recent.
