PETERSON : NEW CARNIVORES FROM MIOCENE OF WESTERN NEBRASKA PAIS 
The lower incisors are laterally compressed. I+ is quite small in comparison 
with that of Canis, while I, and Is, though small, are in better proportion. The 
canine is robust and resembles that of Canis occidentalis very closely, the cross-section 
of the crown being somewhat more regularly oval and less excavated on the antero- 
internal angle. Pz is a small single-rooted tooth with the crown extended well 
forward from the base, the apex being nearly directly over the anterior face of the 
root. The tooth is isolated by diastemata, of which the one in front of it is the longer. 
The next three premolars are also well separated in the jaw. Pz and Ps have simple 
conical crowns with larger posterior than anterior bases and their shape and relative 
diameters are quite similar to those in Daphawnus, while P+ is somewhat enlarged 
and has a strong posterior cusp and prominent cingulum similar to some species 
from the Oligocene, Daphwnus dodgei Scott and Temnocyon altigenis Cope from the 
John Day formation of Oregon. 
In Mj; (carnassial) is observed the greatest change from what appears in the 
Oligocene form in the direction of the more recent type. It is at once seen that this 
tooth has increased in its antero-posterior diameter, the metaconid is situated lower 
down,’ and the hypoconid is bluntly trenchant and is greatly developed, while the 
entoconid is rather small. The tooth is not, however, modified into the perfect 
shearing blade met with in Canis, as it still retains to a greater or less extent the 
conical structure of the tubercles so characteristic of Daphawnus and its ancestors, the 
Miacide. Mz is quite large ; the trigonid is raised only very slightly above the heel ; 
the proto-, para-, and metaconids are fused into a more or less solid and obtuse mass, 
the protoconid being the largest of the three, while the paraconid is represented only 
as a basal heel on the antero-internal angle. The heel is quite large and is occupied 
principally by an antero-posteriorly placed ridge (hypoconid) which is low and 
located nearer the external than the internal border. The entoconid is represented 
by a low and oblique ledge on the postero-internal angle of the crown. Mz is single- 
rooted and is reduced to a small oval-shaped crown with a slight elevation on the 
anterior half, while postero-internally there is a shallow valley produced, to some 
extent by trituration. The size of the tooth with reference to the one preceding it 
is proportionally the same as in Daphenus felinus here used for comparison. 
° Tt is interesting to note that Cynodesmus brachypus from the Miocene of the Laramie Peak locality is apparently 
further advanced towards the recent dogs in having the premolars larger, M} reduced and the lower carnassial of less 
transverse diameter. 
