TERTIARY 7ERTEBRATE FOSSILS. 



523 



known from the Lower Miocene. The skull of another species is shown 

 in fig : 97. The type specimen was discovered in aortheastern Colorado, 

 where so many other extinct mammals have been found. 







Fia. 95. 

 N 



. ural Biz 



The Oreodon beds nexl above are especially rich in such remains, 

 and the skull of one typical form is shown in fig. 98 (p. 524). In these 



Fi... 97.— Skull i I a 9b; with I 



. 



Miocene strata the horse family is well represented, and typical specimens 

 of the genus Mesohippus are given in fig. 101, with two other series from 

 the Pliocene for comparison. 



