MIOHIPPUS. 



61 



Miohippus longicristis Cope, 1S78. Spec, indet. 

 Plate 5.1. 



Anchitherium longicristis, sp. nov., Cope, E. D. "On Some of the Characters of the Miocene Fauna of Oregon," Proc. Amer. Philos. 

 Soc. Vol. XVIII, 1878-1880 (sig. dated Dec. 26, 1878), p. 75, no figure. Palceontological Bull. No. 30, " Dec. 3, 1878." 



Horizon and LocaUiy. — (Cope) " Miocene of Oregon." Horizon John Day. Name of collector not given. 



Type. — The type has apparently been misplaced, not being found (1915) in the American Museum Cope collection. 

 (Cope) "The best specimen representing it [this species] consists of a right maxillary bone, which supports all the molars 

 excepting the last." Measurements: (Cope) p'-m 2 .082; p 1-4 .044; p l a.p. .013, tr. .014; m 2 a.p. .0125, tr. .0165. Cotype. 

 Amer. Mus. 7268, a lower jaw referred by Cope to the same species. 



Type figure. — Type misplaced or lost. 



Characters. — (Cope) (1) Compared with MesoMppus bairdii; (2) infraorbital foramen above p 3 ; (3) no anterior basal 

 tubercles; (4) anterior eingulum with a tubercle; (5) posterior cingulum with a large trihedral hypostyle; (6) external 

 cingulum not strongly marked; (7) median ridges of paracone and metacone not very distinct. 



(Matthew, 1913) An animal of smaller size according to Cope's measurements than any other horse in the John 

 Day collection. Molars of cotype narrower than in other species of John Day Miohippus. This species will remain 

 indeterminate until the type can be found. 



Miohippus primus, sp. nov. 

 Plates 3.13, 4.5. Text Fig. 39. 



A/o. 7291 Type fp ret:) 

 A . M. 



M,oh ippus primus 



Fig. 39. Type of Miohippus primus Osborn, Amer. Mus. 7291, skull containing superior grinding teeth, p 3 -nr. 

 (Upper) Lateral view of left side of skull, partly reversed in drawing. One-half natural size. (Lower) Crown view of 

 p 3 -m 2 of the left side. Natural size. 



Horizon and locality — Middle John Day of Oregon, Diceratherium zone. Type collected by J. L. Wortman, 1S79. 



Type— Amer. Mus. Cope Coll. 7291 . Fragmentary adult skull containing the superior grinding teeth, p 4 -m 3 . Para- 

 type. Juvenile skull containing dp ] -m 2 , Amer. Mus. 7271. Measurements: (Matthew) dp 1 a.p. .011, tr. .074; dp 2 a.p. 

 .0193, tr. .0155; dp 3 a.p. .0166, tr. .0157; dp 4 a.p. .017, tr. .0173; m 1 a.p. .0162, tr. .OH); nr a.p., .0151, tr. .0187. 



Type figure— Plates 3.13, 4.5, text Fig. 39 of this Memoir. 



Characters.— (Matthew, 1913) (1) An animal of smaller size than the types of M. anceps or AC annectens, of larger 

 size than the type of AC equiceps or M. brachylophus. (2) Premolars slightly broader transversely than molars, while in 

 type of M. anceps they are narrower transversely than the molars; (3) vestigial internal cingulum; (4) no medivallum cusp; 



