CREODONTA. 
119 
in the wide posterior part of the fourth premolar; in the latter, this tooth is 
narrow throughout. 
The posterior part of the cranium is preserved to a point a little behind 
the orbits. It is long and narrow, relatively even more so than in the 
Opossum, and is surmounted by an elevated sagittal crest throughout its 
length. The squamosal bone has a considerable extent upward and forward, 
but does not approach near the frontal, although the latter is extended 
downward and backward. This wide separation is characteristic of the 
Opossums; they approach nearer in Ursus, Canis, and Felis. 
3Ieasurements. 
M. 
Leugth of the superior molar series from the cauiue. 0. 082 
Length from the canine to the first premolar. 0 009 
Length from the first to the second premolar... 0. 000 
Length of the true molars... 0. 032 
Width of the base of the third premolar. 0.000 
Width of the base of the fourth i)remolar. 0. 009 
Width of the base of the last true molar. 0. 013 
Vertical diameter of the inferior canine. 0. 010 
Transverse diameter of the same. 0. 000 
Length of the base of the second premolar.. 0. 007 
Length of the base of the last molar. 0. 0085 
Length of the symphysis. 0. 035 
Depth of the ramus at the first premolar. 0. 020 
Depth of the same at the last molar .. 0. 023 
Length of the brain-case preserved.. 0. 070 
Transverse diameter of the same just behind the orbits... 0.0.3 
There are four cervical, two dorsal, six lumbar, and thirteen caudal 
vertebrse preserved, all more or less injured. The atlas has a large trans¬ 
verse process, which is perforated by the vertebral foramen, as in true Car¬ 
nivora, thus differing from DidelpJiys and Macropus. The perforation enters 
the base of the transverse process posteriorly, and issues at its middle infe- 
riorly, thus resembling Felis rather than Canis. There is a slight notch at 
the posterior base of the neurapophysis, not a deep one as in Macropus, nor 
a continuum as in Canis. A well-preserved dorsal vertebra is robust, and the 
stout diapophyses stand on the posterior inferior portion of the neural arch. 
This arch is elevated, and the spine is narrow. The centrum is regularly 
convex in section, and without carinai. 
