214 



specimen the parietal surface is deeply depressed on each side of the sagittal 

 crest. In another specimen a pair of well-marked grooves follow the course of 

 the lore part of the squamous suture, one in front, the other behind it. In all 

 the specimens the front groove is more or less distinct; in some of them the 

 back groove is barely perceptible. 



The auditory capsules are ovoidal, with the greater diameter fore and aft, 

 and the length exceeding the width. They extend from the paramastoid 

 process forward to the middle line of the glenoid articular surface, and project 

 below the level of this for half their length. 



The face of Oreodon superbus differs from that of the other species of the 

 genus more than it does among these. It especially differs in the position of 

 the infra-orbital foramen, and in the great proportionate depth of the infra- 

 orbital arch. In the other known species of Oreodon the infra-orbital fora- 

 men occupies a position above the third premolar. In O. superbus it is placed 

 above the last premolar, as in Merychyus. In Merycochcerus it is placed fur- 

 ther back over the interval of the first and second true molars. The infra- 

 orbital arch is proportionately as deep as in Merycochoerus, and like it presents 

 a broad, nearly flat surface, extending forward below the position of the lach- 

 rymal fossa. The latter is relatively shallow. The forehead is more flat than 

 is usual in Oreodon Culbertsoni. The anterior nasal orifice is like that in other 

 species of the genus. 



The teeth of Oreodon superbus, so far as we have had the opportunity of 

 examining them, appear to agree in all respects with those of the other known 

 species. 



Fig. 16, Plate II, represents a fragment of the lower jaw, natural size, con- 

 taining the premolars and the first molar. A view of the triturating surfaces 

 of the premolars is given in Fig. 9, Plate VII. 



Figs. 7, 8, Plate VII, represent a first molar, part of the second, and the 

 last molar from a lower-jaw specimen. 



Fig. 10, of the same plate, represents a facial specimen, with a view of the 

 forehead, one-half the natural size. 



Measurements obtained from several specimens of portions of skulls of 

 Oreodon superbus arc as follows : 



Estimated length of skull, approximating 14 inches. 



