206 



HENRY F. OSBORN 



From this time on to the summit of the Eocene we are passing into 

 the third faunal phase, or divergence and independent evolution of 

 the Hfe of Europe and America. Consequently close correlation is 



WYOMING CONGLOMERATE 



C//'n ta therium 

 {very abundant) 



Mesatirhinus 

 Z/intatherTUm Manteoceras 



Palaeosyops 

 (very abundant) 



Fig. 2.— Columnar section of the Bridger formation, Henrys Fork, western Wyo- 

 ming. After studies by Matthew and Granger, 1902. 



almost impossible; at no period in the Tertiary were the Nearctic 

 and Palearctic faunas so widely separated. 



MiMe.— With the American Bridger, i,8oo feet in thickness, we 

 enter the Middle Eocene and broadly compare the Lower Bridger 



