PETERSON : NEW CARNIVORES FROM MIOCENE OF WESTERN NEBRASKA 217 
trum is elongate, narrow, and depressed, with a thin and inconspicuous hypopophy- 
sial keel.” In Daphawnodon superbus the centrum, though somewhat depressed, is 
short in comparison with that of Canis and the hypopophysial keel is more strongly 
developed than in the latter. The ventral face of the centrum in the present genus 
is not nearly as concave antero-posteriorly as in the dog, and the ventral keel ter- 
minates posteriorly in a broader area, which 
is extended downward very slightly so as to 
form of its posterior three-fourths a slight 
antero-posterior concavity, but there is no 
prominent tubercle as in Canis. The articu- 
lation for the atlas is more convex and rises 
Fic. 7. Lateral and Posterior Views of Axis of 
D. superbus. 4 nat. size. 
higher upon the sides than in Canis and is 
apparently not materially changed from 
that in the Oligocene form. The odontoid process also agrees with Professor 
Scott’s description of that in the older form, which he says is “a long, slender, 
bluntly pointed peg, with a heavy, rounded ridge upon its dorsal surface, which 
is continued back along the floor of the neural canal.” The transverse process 
is heavier, shorter, and is more nearly parallel to the centrum than in Canis, 
which is also characteristic of Daphwnus. On the lower border of the transverse 
process is developed an inferior branch or costal element (see Fig. 7) which is rather 
unusual on the axis among the dogs and is not mentioned by Scott in his descrip- 
tion of this process in Daphenus. The vertebraxterial canal is apparently slightly 
further forward than in Daphenus, but it is still further back and slightly longer 
than in Canis. The neural canal is large, as in Daphawnus, and does not contract 
so much towards the hinder end asin Canis. The spinous process is a long high 
keel which is produced into a laterally compressed process anteriorly, rapidly ex- 
pands posteriorly, and is proportionally lighter than in the cats, ¢. g., Melis leo. ‘The 
posterior face of the spine is excavated somewhat asin Felis, though in a less degree, 
and forms a different attachment for the cervical muscles than is seen on the con- 
vex and rugose surface in Canis. According to Scott, the neural spine in Daphenus 
corresponds practically to the description here given. 
In Cynodesmus brachypus the centrum of the axis is long and narrow and in its 
general features, including the inferior keel and the odontoid process, answers more 
nearly to that of Canis than to that of Daphenus and Daphenodon ,while the neural 
spine is extremely long and overhanging both anteriorly and posteriorly. The 
latter process is proportionally longer than that in Leo, and tapers more gradually 
from the base of the postzygapophyses to the free end as in the Hocene creodonts. 
