osborn: OLIGOCENE, MIOCENE, pliocene equid^e. 



(Matthew, 1913) (11) Lachrymal fossa shallow; (12) infraorbital foramen above posterior end of p 3 ; (3) tubercle 

 in medivallum; (14) m 3 slightly smaller than m 1-2 ; (15) distinct cusp on anterior border of cingulum; (16) lower dentition 

 shows strong crest on outer side of hypoconulid of m 3 . 



Anchitherium brachylophum, 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), pp. 74, 75, no figure. Palceontological Bull. No. 30," Dec. 3, 1878." 



Horizon mid Locality. — (Cope) "Miocene of Oregon." Horizon, (?) Middle John Day, Diceratherium zone. Name 

 of collector not given. 



Type. — Amer. Mus. Cope Coll. No. 7260. (Cope) "Portions of maxillary bones supporting molar teeth." A frag- 

 ment of the upper jaw with m 1-2 . Measurements: (Cope) length of m 1-2 .030; m 1 a.p. .015, tr. .017; dimensions same as 

 those of M. equiceps. 



Type figure. — Text Fig. 38 of this Memoir. 



Characters. — (Cope, 1878) " The median and inner tubercles are not deeply separated, and the former are cut off 



Fig. 38. Miohippus brachylophus Cope. (Left) Amer. Mus. Cope Coll. 7260, type, m 1-2 of the left side, crown and 

 side views. (Right) Amer. Mus. 7262, referred specimen, crown view of superior molar-premolar series of the left side. 

 All figures natural size. Drawing by B. Yoshihara. 



from the external crescents by a deep fissure. There is no tubercle between the bases of the inner cones, nor is there any 

 internal cingulum. The anterior cingulum does not develop a distinct tubercle, and does not extend to the anterior 

 extremity of the anterior outer crescent. The posterior cingulum develops a large trihedral tubercle, and then extends 

 nearly to the external crescent. The external cingulum is robust, and the external columns are prominent; the interven- 

 ing spaces are impressed, and have a distinct median ridge. Enamel smooth or slightly regose at base of crown." 



(Matthew, 1913) (1) No cingulum around protocone; (2) no basal cusp in medivallum; (3) no distinct cusp on the 

 anterior cingulum; (4) parastyle on p 2 less prominent than type of M. equiceps. This species is regarded by Matthew as 

 rather close to M. equiceps. An animal of the same size and from the same general level as M. equiceps is represented by 

 a fine skull, Amer. Mus. 7262, which is provisionally referred to this species. Provisionally referred specimens are also 

 palates with teeth, Amer. Mus. 7282, 7292, and the upper jaw, Amer. Mus. 7266. 



Miohippus brachylophus Cope, 1878. 



Plates 3.9, 5.3. Text Fig. 38. 



