CORYPnODON. 
221 
open angle, as in Bliinocerns. The bridge which separates the foramen ovale 
from the foramen lacerum is produced downward in a short, longitudinal, 
sharp-edged process. The basicranial axis is stout, and bears on each side 
a longitudinal oval facet, whose middle is opposite the. postglenoid process. 
Between their anterior portions, tlie axis is grooved. The palato-pterygoid 
laminae are nowhere perforate, but there is a basin-like concavity just above 
the inferior angle, at the external base. 
The incisor teeth are separated by spaces as wide as the diameter of 
their roots. The external are a little the smallest, and the crowns the most 
oblique; the length of crown is greatest in the middle pair, where it 
equals the width. The anterior and posterior faces of the crown are both 
convex, the former much the more so. The inner base is marked by a low 
cingulum. 
The canine teeth are very large, and are well worn on the anterior 
face by use. The section of the crown is triangular, forming nearly 
a spherical right-angle triangle. In the longitudinal direction, the posterior 
face is a little concave, the anterior a little convex. There is no secondary 
ridge on either of them. The diastema is short and concave. 
The molars are in good preservation, but the first true molar is so worn by 
mastication as to obscure its structure. The form of the last molar is an irreg¬ 
ular transverse oval, with the posterior border strongly convex or angular. 
This angulation is more pronounced than in C. radians. The posterior crest 
is also angulate, so that while the inner portion is parallel with the anterior 
crest, the outer portion converges toward it, but not so strongly as in G. 
molestus. The anterior fold sends a fold downward and backward at each 
end, the inner of which is continued as a basal cingulum as far as the 
posterior angle. The anterior cingulum is strong, but it does not pass round 
the external base of the tooth. There is an imperfect cingulum round the 
interior extremity of the last two molars, but none on either extremity of 
any of the other teeth. The posterior external V of the penultimate molar 
is wide from border to border; the representative of the anterior V is a 
protruding trihedral cone, quite distinct from the posterior. The anterior 
transverse crest sends downward posteriorly a fold at each end, the 
