PARAHIPPUS. 



85 



Parahippus australis Leidy 1S73. 



Text Fig. 



(30. 



Anchitherium (?) australe, Leidy, Joseph. "Contributions to the Extinct Vertebrate Fauna of the Western Territories," Rept. 

 U. S. Geol. Surv. Terr. F. V. Hayden, Vol. I, Ft. I, 1873, pp. 250-251, PL xx, fig. 19. 



Horizon and locality. — A well at Independence, Washington County, Texas, Upper Miocene. The type was found in 

 association with a second or third upper molar (op. cif. pi. xxii, fig. 16) of the right side which was provisionally referred 

 by Leidy to the species Protohippus perditus (?) which is an Upper Miocene stage. Name of collector not given. 



Type. — Acad. Nat. Sci. Phila. Coll. Second upper premolar of the right side. As described by Leidy (1873, p. 250) 

 "It is the first of the series of six large upper molars as existing in equine animals, but exhibits in front the impress of a 

 premolar [p l ] larger than usual in members of the order. The specimen is broken at its outer part, but the remainder is 

 nearly as characteristic as if the whole were complete." Measurements: (Leidy, p. 251) "The estimated size of the tooth 

 is 11 lines in diameter anteroposteriorly and nearly the same measurement transversely." 



Type figure. — Text Fig. 60 of this Memoir. 



Characters. — (Leidy, 1873, Osborn, 1918) (1) An oblique valley extends from the inner side and ends in a foot-like 

 expansion [parastyle]; (2) back of the center of the triturating surface a crescentic enamel lake [post-f ossette] ; (3) devoid 



Fig. 60. Original figure of the type of Parahippus australis Leidy, Acad. Nat. .Sci. Phila. Coll., p 2 of the right side. 

 Natural size. After Leidy, 1873, PI. xx, fig. 19. 



of cement; (4) inner and intermediate lobes [protocone, hypocone] somewhat fuller than in Anchitherium ; (5) resembling 

 Anchippus in other features but differing from both Anchippus and Parahippus in the absence of the crochet [a fold which 

 may be worn off]. The tooth also resembles the type of Hypohippus in (6) the uncertainty as to its generic relationship. 

 Leidy refers it to Anchitherium. 



Altippus ta.rus gen. et sp. nov., Douglass, Earl. "Fossil Horses from North Dakota and Montana," Ann. Carnegie Mus., Vol. IV, 

 Nos. Ill, IV, Apr, 1908, pp. 271-273, pl. LXVII, figs. 3, 4, PI. lxviii, figs. 6-8. 



Horizon and locality. — Near Woodin Station, on Divide Creek, about six miles south of the continental divide, Silver 

 Bow County, Montana. Zone of Kntoptychus, therefore Upper Oligocene or Lower Miocene. Type collected by Earl 

 Douglass, 1905. 



Type. — Carnegie Mus. 836 (Douglass). "The type. . . .consists of parts of a skull, the greater portion of a mandible, 

 a radius, portions of two femora, a tibia, a nearly complete hind foot, other bones of toes, and numerous fragments." An 

 immature animal, dp 2 " 4 , m 3 unformed. Measurements: dp^nr .088; m 1 a. p. .015, tr. .018, height of crown .013. 



Type figure. — Text Fig. 62 of this Memoir. 



Characters. — (Douglass, 1908, Osborn, 1918) (1) Metaloph separate from ectoloph; (2) protoloph and metaloph of 



Parahippus taxus Douglass 190S. 



Text Fig. 62. 



