50 BULLETIN 53, UNITED STATES NATIONAL MUSEUM. 



600. [Neohipparion ? sp. undet.] 



Three lower teeth (representing three individuals). Loup 

 Fork (Upper Miocene). Niobrara River, Nebraska. 



Leidy, Journ. Acad. Nat. Sci. Phila. (2), VII, 1869, pi. 19, figs. 

 25-27 (unnamed). 



[Identified by J. W. Gidley.] 



» 



597. [Neohipparion sp. undet.] 



Lower molar of right side. Loup Fork (Upper Miocene). 

 Niobrara River, Nebraska. 



Leidy, Journ. Acad. Nat. Sci. Phila. (2), VII, 1869, pi. 19, fig. 40 

 (unnamed). 



[Identified by J. W. Gidley.] 



3750. Notharctus robustior Leidy. Type. 



Part of left lower jaw with second molar. Bridger (Eocene) . 

 Henrys Fork, Green River, "Wyoming. 



Leidy, Rept. U. S. Geol. Surv. Montana, etc. (Hayden), 1872, p. 264. 



= Hipposy us robustior. 



3752. Notharctus tenebrosus Leidy. Type. 



Nearly complete lower jaw containing all the teeth except p, 

 and the incisors. Bridger (Eocene). Blacks Fork, 

 Green River, Wyoming. 



Leidy, Proc. Acad. Nat. Sci. Phila., 1870, p. 113; Rept. U. S. Geol. 

 Surv. Terr., I, 1873, p. 86, pi. 6, figs. 36, 37. 



2878. Oracodon anceps Marsh. Paratype. 



? Lower premolar. Ceratops beds (Cretaceous). Converse 

 County, Wyoming. 

 Marsh, Amer. Journ. Sci. (3), XLIII, 1892; p. 256, pi. 7, fig. 7. 

 = Cimolomys anceps. 



2 141. Oracodon conulus Marsh. Type. 



Upper premolar. Ceratops beds (Cretaceous). Wyoming. 

 Marsh, Amer. Journ. Sci. (3), XLIII, 1892, p. 256, pi. 7, fig. 8. 



137. Oreodon culbertsonii Leidy. Plesiotype. 



Cranium and jaw. White River (Oligocene). Nebraska. 



Leidy, Owen'sRept. Geol Surv. Wis., Iowa, and Minn., 1852, p. 548, 

 pi. 10, figs. 5, 6; Smithsonian Contrib. to Knowl., VI, Art. VII, 

 1854, p. 45, pi. 2, fig. 3. 



2506. Oreodon culbertsonii Leidy. Plesiotype. 



Cranium and jaw. White River (Oligocene). Nebraska. 



Leidy, Smithsonian Contrib. to Knowl., VI, Art. VII, 1854, p. 45, 

 pi. 2, figs. 1,2. 



136. Oreodon gracilis Leidy. Plesiotype. 



Cranium and jaw. White River (Oligocene). Nebraska. 



Leidy, Journ. Acad. Nat. Sci. Phila. (2), VII, '1869, p. 94, pi. 6, 

 figs. 2, 3. 



