PROTOHIPPUS. 



133 



less pertained to the same animal, although it is rather larger in proportion.' There is no trace of this tooth with the 

 original material." 



Characters. — (Matthew, 1913) As shown in the accompanying figures of the type specimen, the pes is generically 

 indeterminate; it belongs either to Protohippus or to Hipparion, probably to the former genus. The type includes a Mts. 

 Ill of moderate length, approximately lacking the lateral facet for the cuneiform (a facet typically present in Pliohippus); 



/Veotype 



Protoh ippus parvulus 



Fig. 105. Neotype half worn upper molar found with the type skeletal fragments of Protohippus (Equus) parvulus, 

 Marsh, Yale Mus. 11342, now considered referable to the same species and possibly to the same individual as the 

 type. 



the lateral metatarsals are rather heavy; the hoofs are of medium width; the navicular is low and broad; the ulna is 

 coalesced suturally with the radius at the distal end, apparently also along the shaft. (Osborn, 1918) The discovery by 

 Troxell (1916) of the pes of Protohippus (see Fig. 116a) tends to confirm the reference of this type to Protohippus, as a 

 species not remote in size from the type of P. placidus Leidy. 



Protohippus placidus Leidy 1S69. 



Plate 34.4. Text Figs. 106, 107, 116a. 



Protohippus placidus, Leidy, Joseph. "The Extinct Mammalian Fauna of Dakota and Nebraska," Jour. Acad. Nat. Sci. Phila. 

 1869 (2) Vol. VII, pp. 277-279, 463, PI. xviii, type fig. 40, paratypes, figs. 39, 41-48. 



Horizon and locality. — Niobrara River, near Fort Niobrara, Nebraska, Procamelus zone, Nebraska, Lower Pliocene. 

 Type — U. S. Nat. Mus. 621. (Gidley, 1907, p. 887) "A left upper premolar, p 2 ." (Leidy, 1869) "The specimens 



Fig. 106. Original figures of the type of Protohippus placidus Leidy, U. S. Nat. Mus. 621 p 2 (40), and of the 

 paratypes (39, 41-48). Natural size. After Leidy, 1869, PI. xviii, 



