54 the merycoidodontim: 



scaphoid and less on the cuboid than in the ruminants. Characteristic is the slight development of the sustentacu- 

 lum tali, which is represented by a very slightly projecting facet at the distal end of the tuber calcis. 



The cuboid . . . shows the surface for the calcaneum wider than that for the astragalus, which is surely to 

 be regarded as a primitive character; the bone is wide, low, and thickened fore and aft, and the posterior unci- 

 form process is massive but short. The facet for the calcaneum is slightly convex in the anteroposterior direc- 

 tion and projects somewhat over the external side. . . . On the tibial side of the cuboid are two articular surfaces, 

 which are wedged in between the scaphoid and the ectocuneiform; the posterior of this facet is connected with 

 the marked facet for the outer side of the scaphoid. . . . The posterior side of the cuboid is much wider than the 

 anterior. . . . The distal surface is almost wholly occupied by the large, pronounced facet for Mt. IV; that for 

 Mt. V is very small. . . . The scaphoid is wide and low ; the projection for the distal astragalar surface is not 

 strongly developed; the uncinate process on the posterior side is very long and downwardly directed and covers 

 the entocuneiform. . . . On the distal side are three facets for the cuneiform bone. . . . The ectocuneiform and 

 mesocuneiform are fused, as in almost all of the recent artiodactyls; the limits of the two elements are, however, 

 completely marked, since the mesocuneiform is somewhat lower than the ectocuneiform, and in consequence its 

 distal surface lies at a higher level than that of the latter. A delimitation similar to that on the distal side of 

 the scaphoid is traceable on the proximal surface of the united cuneiform, where the facets belonging to the 

 outer and middle cuneiform are not yet united. The ectocuneiform is high, small, and thin; . . . the proximal 

 end has a small facet for the scaphoid, and on the anterior side of it there is a surface for the mesocuneiform and 

 on the distal end facets for Mts. II and III. . . . 



The metatarsals are short, and the lateral ones are longer and stronger. ... As far as the length is con- 

 cerned, the sequence is IV, III, V, II. . . . The manus and pes are developed in an opposite sense in that in the 

 manus the outer side is shortened and in the pes the inner side. Mt. II has a slender, laterally compressed shaft 

 and a flat proximal facet for articular union with the mesocuneiform, and, since this part of the united cuneiform 

 is lower than the ectocuneiform, Mt. II rises higher than III and has a lateral contact with the external cunei- 

 form. . . . On the posterior side of the upper end of Mt. II there is a small facet for the entocuneiform, which is 

 wedged between the posterior uncinate process of the scaphoid and Mt. II. Mt. Ill is very strongly built. . . . 

 It has no union with the mesocuneiform; the entocuneiform, on the other hand, articulates with a strong process 

 from the posterior edge of the upper end. On the opposite side Mt. Ill is supported by the cuboid. . . . Mt. IV 

 is of similar strength to Mt. Ill but is somewhat longer; its tarsal contact is only with the cuboid, which, 

 however, is thereby strengthened, so that the aft process is laterally supported by the posterior hook of the cuboid. 

 On the tibial side of the upper end is a hollow to receive a corresponding projection from Mt. Ill, while the 

 articular union with Mt. V is, on the contrary, very flat. The fifth metatarsal is longer than Mt. II but is of 

 about equal strength. . . . 



The phalanges do not differ from those of the manus. 



Discussion: Cat. No. 12238 Y.P.M. is a partial skeleton, including the skull and jaws, found 

 near Warbonnet Creek, twelve miles north of Harrison, Nebraska. Its age is middle Oligocene. 

 The pes is excellently preserved, and the bones are in articulation. On the ventral surface, close to 

 Mt. II, there was found in the matrix a small elongated bone which certainly appears to represent 

 the hallux. This bone is 17.5 mm. in length, although the proximal end is somewhat damaged. 

 The upper half of the inner side bears a distinct articular facet, while the distal half of the bone is 

 laterally compressed and ends in a blunt point. There is no indication of any phalanges accom- 

 panying this first metatarsal, if such it is. The evidence certainly bears out the assumption that 

 this bone is the last vestige of the hallux, present in the earlier forms, like Protoreodon, but not in 

 the Merycoidodontidse of the upper Oligocene or later, except Leptauchenia and Cyclopidius. 



Cat. No. 12471/2 Y.P.M. , from Nebraska, shows a very large style developed from the cingu- 

 lum between the protocone and hypocone of both M 3 . Cat. No. 12094 Y.P.M. is a skull, with a 

 well-developed single-rooted accessory premolar between the canine and normal first premolar on 

 both side's. The muzzle is elongated, and both P 2 are set obliquely. This extra premolar is prob- 

 ably comparable to that met with occasionally in the long-muzzled species of Canis. 



Schlaikjer (1935, p. 173) found remains of this species exceedingly rare in the Goshen Hole 

 area of Wyoming. Cope and Marsh collected representatives, however, in other Wyoming 

 localities. 



Leidy, in 1870, identified some John Day specimens with his M. culbertsonil, but three years 

 later he suspected that this material probably belonged to Eporeodon bullatus. There are a few 

 isolated fragments of maxillae and rami which are almost identical with the corresponding parts of 



