35 
Between this second surface for maxillary attachment and the lower part 
of the overlap of the flange of the quadrate is the moderately large surface 
for the external application of the posterior expansion of the ectopterygoid. 
Above the contact with the maxillary process, for the full height of the 
anterior wing of the pterygoid, is the surface for the palatine which passes 
externally back over the pterygoid for a varying distance from its anterior 
border. 
At the midlength of the superior border, between the wings, facing 
inward and backward, and occupying the upper end of the posterior, 
internal enclosure between the posterior flange and the posterior wing is a 
rugose, concave surface, oval in outline, which grasps the front lower 
convexity of the process of the basisphenoid. 
The forward end of the anterior wing of the pterygoid is not complete, 
but here the bone thickens slightly downward and supplies a roughened 
narrow surface, directed forward and facing inward, which apparently 
indicates the union with the back termination of the vomer. 
Measurements of Left Pterygoid of Edmontosaurus, Cat. No. 2289. 
Mm. 
Maximum length above (imperfect antero-superiorly) 357 
Maximum length below 184 
Maximum vertical, anterior height above base-level 268 
Maximum vertical, posterior height above base-level 217 
Vertical height, above base-level, of superior border behind surface of contact 
with basisphenoid process 149 
TTUT 
nia- 
Palatine. {Pal.). Figures 3, 13 y and 
18. This element is somewhat trian- 
gular in lateral outline, is highest near 
the front and narrows downward and 
backward to the nearly straight base. 
It is thin and plate-like and when in 
position is almost vertical above the 
postero-superior border of the maxil- 
lary. It is suturally united to the 
maxillary, the jugal, and the ptery- 
goid. The anterior border is shal- 
lowly emarginated in its upper half 
to form the posterior curve of the pos- 
terior nares. In the lower half of the 
border is a roughened sutural surface 
facing forward and slightly outward 
and downward for contact with the 
jugal in the infero-anterior angle of 
the orbital rim. This surface has an 
irregularly oval outline and is about 
twice as high as broad. Behind its 
contact with the jugal the palatine 
fits on the narrow postero-superior 
Figure 18. Right palatine of Edmontosaurus, border of the maxillary back to and 
slightly on to the pos- 
mx, with maxiiiarj- pt, with pterygoid. terior maxillary process. From here 
B 
