466 Annals of the Carnegie Museum. 



The Skull. Lateral Aspect. —The skull (Plate LIX) (Carn. Mas. 

 Cat. Vert. Foss. No. 827) is long, yet the face is quite deep anterior 

 to the orbits. The facial portion is rather long, the anterior margin 

 of the orbit being about midway between the extreme anterior and 

 posterior portions of the skull. The muzzle is comparatively slender 

 as seen from above, but has on its sides broad longitudmal convexities. 

 The general upper contour of the cranium is nearly straight, though 

 the forehead is somewhat concave between the orbits, and back of this 

 the top of the brain-case is somewhat convex. The anterior portion 

 of the skull very much resembles that of Antilocapra, but the shape 

 and contour of the brain-case are very different. In Dromomeryx it 

 is larger and the upper surface does not descend backward as in Anti- 

 locapi-a. In the former the low supra-temporal ridges begin at the 

 postero-internal angles of the bases of the horns and converge back- 

 ward forming a low, broad, sagittal crest about six and one half cen- 

 timeters in length. The orbits are large and the jugal beneath is 

 produced outward into a shelf which is not so wide nor flat as in An- 

 tilocapra. The outer border of the jugal is thickened and it is con- 

 cave transversely beneath. The horns are nearly circular in section 

 above, but are triangular just above the basal wing-like processes. 

 The latter are directed postero-externally. The antero-external faces 

 are concave and the outer borders thickened. The skull is slightly 

 injured in this region, so it is uncertain whether the lachrymal bone 

 reached to the nasal or whether it was separated by the vacuity which 

 lies beneath a part of the posterior portion of the nasals ; but appa- 

 rently the lachrymal was excluded from articulation with the nasals 

 by the antorbital vacuity, as in the Cervidce. The parieto-temporal 

 suture is below the middle of the brain-case which is, according to 

 Brooke," a bovine feature. The temporal ridges are quite heavy and 

 are a little nearer the parieto-temporal suture than they are to the 

 supra-temporal ridges, and they are nearly parallel with both. The 

 zygomatic portion of the squamosal is heavy. The excavation in the 

 squamous portion of the temporal for the external portion of the au- 

 ditory apparatus (ectotympanic) is large and nearly semicircular in 

 form as seen from the side. The mastoid portion of the temporal is 

 heavy, thickened, and rugose. The infraorbital foramen opens above 

 the anterior portion of P^. 



" "On the Classification of the Cervidee, etc.," Proc. Zool. Soc. Lond., 1878, 

 p. 885. 



