ABSTRACT
Two faunal provinces existed throughout the Tertiary, a north temperate and boreal province, and a warm-water Tethys which included northern India, the Mediterranean region, and northern Africa. In the northern province the Senonian and Danian of the Upper Cretaceous are dominantly calcareous and are unconformably overlain by the basal Eocene, made up for the most part of sand and clay. In the Tethyan province, both the Upper Cretaceous and the basal Eocene are represented by impure limestones. At no locality in the boreal province does the combined Danian-basal Eocene section greatly exceed 600 feet, but in the Tethyan province in India a maximum thickness of 2,300 feet of basal Eocene has been determined, unconformably overlying 90 feet of trap, the trap in turn covering 300-400 feet of upper Danian.
The Midway fauna of Texas is clearly allied to the homogeneous biota which inhabited the warm and warm-temperate shores of the Gulf of Mexico and as far south as Brazil, and less definitely a part of the more heterogeneous biota originating in the inshore waters of the old Tethyan sea.
