PARAHIPPUS. 



77 



hypsodont; (3) metalophs united with eetolophs on till grinding teeth; (4) rudimentary or small pli hypostyle except 

 on p 2 ; (5) premolars scarcely larger than molars, their transverse diameter not so great. (6) Preorbital (lachrymal) fossa 

 moderately deep; (7) anterior border of orbit above anterior end of nr. (8) Metatarsals long and slender with lateral 

 digits moderately reduced; (9) first phalanges rather short; (10) ungual phalanges narrow; (11) a small, deep fossette on 

 Mts. Ill for cuboid. 



Referred Specimens. — The characters of the type are confirmed by the referred specimens American Museum 12915, 

 129171), 12921, 12922, 129215, all from the Lower Rosebud. The type represents an animal of smaller size and more brachyo- 

 dont than any other known form of Parahippus, the size and characters of the teeth being very suggestive of Archceohippus, 

 but the orbit is further forward and the lachrymo-malar fossa not very deep. The presence of a crochet on all the superior 

 grinders except p 2 relates this animal to Parahippus. 



Parahippus tyleri Loomis 1908. 

 Plate 9.6,8, 39.10,12. Text Figs. 53, 54, 56. 



Parahippus lyleri sp. nov., Loomis, F. B. "A New Horse from the Lower Miocene," Amer. Jour. Sci. and Arts, (4), Vol. XXVI, 

 No. 152, Aug., 1908, pp. 163-164, fig. 1. 



Fig. 53. Type of Parahippus tyleri Loomis, Amherst College Coll. 1079. (Upper) Original figures of type. One- 

 half natural size. After Loomis, 1908, fig. 1, p. 163. (Lower) Crown view of p 2 -m 3 , drawn by F. B. Loomis. Natural 

 size. 



Horizon and Locality. — Upper part of the Lower Harrison beds, eight miles northeast of Agate, Sioux Co., Nebraska, 

 Promerycochoerus zone, Upper Oligocene. Type collected by Harold Cook, 1907. 



Type. — Amherst College Coll. 1079. (Loomis) " A skull numbered 1079 in the Amherst College Museum which 

 while lacking the brain case preserves all the dentition except the upper canine and the first premolar of the upper and 

 lower jaw." Measurements: length of m 1 " 3 .055; p?-4 .056; m\-% .059. 



Type figure. — Text Fig. 53 of this Memoir. 



Characters. — (Loomis) (1) About one-fourth smaller than P. ncbrascencis. (2) Facial portion of skull moderately 



