566 THE JOURNAL OF GEOLOGY. 



The Seymour Plateau, which is referred to this horizon 

 because of its mid-Pleistocene, or at least post-Equus fauna as 

 determined by Cope, stretches northeast from the Texas and 

 Pacific railway west of Sweetwater, with a width varying from 16 

 to 50 miles, to Red river, north of Vernon, a total length of 160 

 miles. The western border of this ancient lake is sharply defined 

 by a range of gypsum hills, as may be seen on the Fort Worth 

 and Denver railroad east of Quanah. In elevation it varies 

 between 1200 and 1600 feet above sea level, and although at 

 present cut through by many streams, whose beds are sometimes 

 150 feet below the plain, the general flatness of its surface is 

 .still well preserved. 



Of the latest of the divisions of the Pleistocene little can be 

 said, because it has been studied least of all. It comprises the 

 sands of the immediate coast area, which stretch inland in places 

 for 50 miles and more ; the later stream gravels, and other 

 deposits of gravels and sands which are found on the surface at 

 many localities. The sand dunes of the west and southwest also 

 belong here. 



CONCLUSIONS. 



None of the beds of the Eocene having yielded fossils char- 

 acteristic of horizons higher than the lower Claiborne, the depos- 

 its referable to that series are confined to its basal portion. 



Certain forms indicate a connection of the Eocene waters of 

 the Texan region with those of the Pacific. 



In the Texan region dry land probably existed from mid- 

 Eocene times far into the Miocene. 



Although there is a possibility that the lower portion of the 

 deposits referred to the Miocene may prove a little earlier, the 

 fossils so far discovered belong to the upper portion of that 

 stage — the Loup Fork. 



The exact relation of the Loup Fork and the marine Mio- 

 cene of the Deep well is undetermined, 



There exists, both on the Llano Estacado and on the Coastal 

 slope a series of beds, overlying the Loup Fork and underlying 



