EODENTIA. 
299 
passes througli the single lateral palatine foramen, which is preceded by a 
groove of the maxillary bone. The auditory bullae are very large; they 
are subsemiglobular and compressed. The humerus preserved lacks epiph¬ 
yses ; its sections are triangular, owing to the presence of aliform angles. 
One proximal directed inward and backward is much more prominent than 
the deltoid crest opposite to it. The ulna is compressed posteriorly, and 
the olecranon is short. 
Measurements. 
Length of the superior raolar series. 
Length of the first superior molar. 
Length of the fourth superior molar. 
Length of the crowns of the inferior molars. 
Length of the first inferior molar. 
V/idth of the same. 
Width of the last inferior molar. 
Transverse diameter of the inferior incisor.. 
Depth of the ramus at the first molar. 
Width of the ramus at the last molar. 
norizontal diameter of the auditory bulla___ 
M. 
0.0150 
0.0050 
0.0038 
0. 0160 
0. 0050 
0. 0040 
0.0035 
0.0040 
0. 0140 
0. 0080 
0. 0150 
The younger specimen is instructive, as showing the primitive condi¬ 
tion of the fossettes and inflections of the mature dentition. The first molar 
is unworn, the fourth but little, and the second and third a little more 
worn. In the crown of the first, the outer inflection is seen to be continu¬ 
ous with the posterior transverse fossette, which notches the internal and 
posterior borders also. The anterior crescent-like fossette notches the 
antero-lateral borders. In the following two teeth, the posterior fossette is 
distinct from the outer inflection, but is a second or posterior internal 
inflection, soon becoming isolated on attrition. The anterior transverse 
fossette is isolated in these specimens. In the fourth molar, both the ante¬ 
rior and posterior fossettes are inflections from the inner side, thus giving 
three for that side, as in Chalicomys. Thus it is evident that in its immature 
state the dentition of this species approaches much more nearly that assigned 
by Pomel to Chalicomys than it does at maturity; for that a little attrition 
would soon produce the pattern seen in the specimen first described is 
entirely obvious. 
A comparison of this species with the S. nebrascensis, Leidy, reveals a 
number of differences. In that species, the first and second molars in both 
