1884, ] 539 (Cope. 
foramina are well separated from each other, as in the species of Meryco- 
chorus. The space between them is about equal to that between each 
one and the superciliary border. There is a large postpariétal foramen 
near the pariéto-squamosal suture. If the supraglenoid foramen be pres- 
ent it is not distinguishable in the specimen. The orbit is rounded sub- 
quadrate, with the inferior anterior angle a little produced. 
The ascending process of the mandible is relatively elevated. The 
horizontal ramus narrows rapidly anteriorly, and the symphysis mandibuli 
is produced so as to rise at a very low angle. The alveolar portion is © 
horizontal. 
The superior incisors are small and their apices are but little expanded, 
the external the most so. ‘They are directed vertically downwards. The 
superior canine is quite small; its crown exceeds in length that of the 
first premolar by but little, and is directed a little posteriorly as well as 
downwards. The roots of the first premolar are not as well distinguished 
as in many other species, and are united in their extra-alveolar part at 
least. The same is true of the second premolar. The apex of the cutting 
edge is in line with the anterior border of the crown ; the rest of the edge 
rises obliquely backwards. In the third premolar there is a slight bevel in 
front of the apex, which is much better developed on the fourth. These 
teeth are more truncate than the corresponding ones of the species of 
Oreodon and Eucrotaphus, and the larger species of Merycocherus. The 
external faces of P-m. iand ii are convex; that of P-m. iv is concave, 
but without the reverted vertical borders seen in Oreodon culbertsont. The 
first true molar has long roots and a short crown. 'The last two molars 
have crowns of a more elongate character, with well developed anterior 
and middle ridges. The latter are not so prominent as those of the molars 
of the Merychyus zygomaticus. : 
The inferior incisors are directed upwards at an angle of about 80°. 
They are similar and closely packed. The inferior canine is in close con- 
tact with the third incisor, from which it differs in its larger, leaf-shaped 
crown. The inferior first premolar is a slender one-rooted caniniform 
tooth, with narrow crown and acute apex. The second premolar is one- 
rooted, and has a leaf-shaped crown, with acute-angled apex. The third 
is two-rooted, and has a wider and nearly symmetrical crown, The fourth 
is much larger, and its elongate crown laps inside of that of the third. 
Its low angular apex is median. The last inferior true molar is dispro- 
portionately larger than the others. No external cingula. 
Measurements of Skull. M. 
Length from occipital condyle to premaxillary border.. .161 
i uy ms ut « pyostglenoid process... .080 
ie Af big ve « postfrontal process... .078 
ie ihe a nt ‘* preorbital border..... 130 
VOTO Ce celaeie nee vale ee be vee .0250 
Diameters of orbit - 
transverse. .... SETA ORES Ye sis OROO 
