72 



CENOZOIC MAMMAL HORIZONS 



Parahippus 

 Moropus 



Merycochosrus 

 (abundant and 

 characteristic) 

 ? Merychyus 

 Blastomeryx 

 Oxydacty/us 

 Test ado 



Amphicyon 

 (primitive stage) 



LEVEL OF AGATE SPRING 



D/'ceratherium 

 Moropus 

 Df'nohyus 



Deemonelix 



beds'' ? Merychyus 



(pr/m/'t/i/e stage) 



Promerycochoerus 

 van tasselensJs 



Pdrah> 



ippus 



Promerycochoerus 

 carri'kerl 



Mesoreodon 

 Protomeryx 



Diceratherium 



Leptauchenia 

 ?Mesoreodon 



Leptaucheni\ 



Fig. 13.— Columnar section of the Gering, Monroe Creek, and Harrison formations, based on Peterson's 

 observations in western Nebraska. (See section A, Pi. II.) 



