WHITE EIVER EPOCH. 



13 



xnined from it a few 

 genera of Tertiary and 

 Upper Eocene character. 

 Such are of Mesodonta, 

 the genus Hyopsodus, and 

 of Ungulata, the Perisso- 

 dactyle form Amynodon. i 



THE WHITE RIVER. 



I 



The materials of t 



which the beds of this & 



formation are composed f 



in their eastern division, T 



are calcai-eous clays and ^ 



marls, alternating with a ? 



few unimportant strata ^ 



of light-colored sand- « 



stone. They are white i 



and gray, with occa- o- 



sionally a pink and red, g- 



and sometimes greenish S. 



tinges. The beds of the ? 



western deposit in Ore- i 



gon consist of a more ^ 



or less indurated mud, g 



which is, according to o 



King, of trachytic ori- a 



gin, which is rarely hard, 1 

 and frequently rather 

 soft. Its predominating 

 color is light green, but 

 is frequently olive and 

 light brown. The depth 

 of the formation on the 





