81 
As in Brown’s specimen, the ophthalmic branch of the fifth nerve runs down- 
ward in a large, open channel. Posteriorly this channel is overhung by a 
flange of considerable size. Below and behind the flange of the basisphenoid 
is a large, elliptical foramen for the lower entrance of the internal carotid 
artery. The foramen for the passage of the jugular vein does not pierce the 
external surface of the brain case as in Edmontosaurus, but runs from the 
internal surface of the brain case into the foramen lacerum posterus. The 
exits for the first, second, third, and fourth nerves are as in Edmontosaurus. 
Oj ft The palatine, pterygoid, and 
livl ectopterygoid .closely resemble 
L ‘ those elements in E. regalis. Just 
below the notch which forms the 
posterior border of the posterior 
nares, the anterior border of the 
palatine is overlapped by the 
interno-inferior point of the 
lachrymal. 
The vomer is not present. 
The maxilla resembles that 
element in T. annedens. There 
are fifty-two vertical rows of teeth 
in the maxilla and the general 
arrangement and replacement 
are as in other members of the 
Hadrosauridae. The enamel face 
is moderately long and slender 
with bluntly rounded apex, thus 
differing from the diamond-shap- 
ed dentary teeth. The median 
keel is very high in the upper or 
basal portion, but decreases in 
height as it proceeds downward 
and practically disappears at the 
apex. The lateral faces are 
concave and the 
_ _ and 
Natural size. ' sparsely studded with papillae. 
There is a faint, longitudinal striation near the tip. There were two teeth, 
of the same series, in the triturating face at the same time. As the re- 
placement is from the inner, not the enamel, side, both teeth in the cutting 
surface have an enamel face; whereas in the dentary the replacement is 
from the enamel side, so that the enamel face of one tooth must be worn 
away before the apex of its successor comes into use. 
On the superior surface of the maxilla, below the extreme anterior 
tip of the jugal, is a single, large foramen. 
The mandible of T. saskatchewanensis contains all the elements 
common to the hadrosaurian jaw, all of which, except the predentary, 
are well preserved and articulated on the left side. 
Figure 3 A. 
Enamel face of dentary teeth. 3 A: T. Saskatchewanensis. transversely 
the twenty-firs . _ _ 1 .1 
series. Natural size. 3B:T annectens (Marsh). After Marsh. 
Figure 3 B. 
mel face of dentary teeth. 3 A: T. Sl 
Type. Taken from the twenty-first to twenty-fourth vertical edges are slightly raised 
The dentary is long and moderately massive, being more robust than 
that element in T. annectens. The edentulous portion constitutes about 
three-eighths of its length and is more strongly decurved than in T . 
