OF WESTERN NORTH AMERICA. 



117 



UPPER MIOCENE AND ? LOWER PLIOCENE— Continued. 



PERISSODACTVLA— Continued. 



Hypohippus affinis Leidy 



Hypohippus sp 



Parahippus cognatus Leidy 



Merychippus insignis Leidy 



Merychippus calamarius (Cope). 



Protohippus mirabilis Leidy 



Protohippus perditus Leidy 



Protohippus plaeidus Leidy 



Protohippus supremus Leidy 



Protohippus pernix (Marsh) 



Protohippus robustus (Marsh) . . , 

 ? Protohippus parvulus (Marsh) . 

 Protohippus gracilis (Marsh) 



1. I 2. 



Protohippus spectans (Cope) 



Protohippus pachyops Cope 



Protohippus castiili Cope 



Protohippus profectus Cope.. 



Protohippus simus Gidley 



Protohippus fossulatus Cope 



Protohippus interpolatus Cope. . . 



Neohipparion whitneyi Gidley 



Neohipparion occidentale (Leidy) . 

 Neohipparion speciosum (Leidy).. 



Neohipparion affine (Leidy) 



Neohipparion gratum (Leidy) 



Neohipparion calamariLun (Cope). 

 Neohipparion relictum (Cope) 



Neohipparion montezumse (Leidy). 

 Neohipparion peninsulatum (Cope) . 

 Neohipparion lenticularis (Cope).. . 



Neohipparion dolichops Gidley 



Neohipparion niobrarense Gidley. . . 

 Neohipparion sinclairii Wortman. . 



Neohipparion retrusum Cope 



Neohipparion princeps Leidy 



Neohipparion eurystylus (Cope) . 

 Neohipparion ingenuum (Leidy) . 

 Neohipparion rectidens (Cope) . . 

 Neohipparion plicatile (Leidy).. 



ARTIODACTYLA. 



DlCOTYLlD^ ( = TAGASSmD^). 



Prosthennops crassigenis Gidley . 



Prosthennops serus (Cope) 



" Platygonus " striatus Marsh. . 



OREODONTIDiE ( = AGRIO( HCERID^) , 



Pronomotherium altiramis Douglass 



? MerycochcErus cenopus Scott & Osborn 



? Merycochoerus sp 



Merychyus elegans Leidy 



? Merychyus medius Leidy 



? Merychyus major Leidy 



? Merychyus sp 



Camelid.^:. 



Procamelus occidentalis Leidy 



Procamelus robustus Leidy . ' 



Procamelus gracilis Leidy 



? Procamelus prehensilis (Cope) . . . 



Procamelus leptognathus Cope 



Procamelus major Leidy 



Procamelus minor Leidy 



Procamelus minimus Leidy 



Procamelus madisonius Douglass. 



Procamelus lacustris Douglass 



Procamelus ^p. div 



Protolabis montanus Douglass. . . 



Protolabis serus (Douglass) 



Pliauchenia humphreysiana Cope 



Pliauchenia sp 



Pliauchenia vera sp. nov.a 



Pliauchenia minima Wortman 



Pliauchenia sp. max 



4. 1 5. 1 



Mexico. 



X 

 X 



Bijou liills 



Mexico. 

 Mexico. 

 X 



Mexico. 



a'^FHauchenia humphreysiana Cope," Wortman, 1899, not ot Cope. Jaw larger, more robubt, 

 premolars more reduced, p. 2 absent, while in P. humphresiana it is vestigial. 



