20 



VERTEBRATA OF THE TERTIARY. 



gypsum. Remains of the fauna are found in clay deposits along several 

 of the Atlantic Rivers, as the Delaware and Potomac. 



It is probable that the formation in the western localities mentioned is 

 mostly sand. Near Carson City, Nevada, it consists of a light-buff friable 

 calcareous sandstone. 



This is the Upper Pliocene of King, and the Post-Pliocene of various 

 ■writers. 



Fig. tki. — Sinid Hills Noitliwe.steru Ni braska i'rom Hayden. 



