39 
From a lateral aspect the squamosal presents a very wide surface 
between its upper border and the top of the excavation or cotylus for the 
head of the quadrate, and a comparison with other known skulls shows 
that this is a peculiarity of all members of the Lambeosaurinae. In this 
sub-family, when the skull is viewed from the side with the tooth rows in an 
horizontal position, the top of the infratemporal opening extends above 
the proximal end of the quadrate, whereas in the Hadrosaurinae and Sauro- 
lophinse it is on the same level or below. The cotylus for the head of the 
quadrate is deep, with a pointed process of moderate length extending down 
in front of the quadrate, and a longer and more robust process at the rear. 
The latter is applied to the outer anterior surface of the paraoccipital 
process in the usual way. Internally, the squamosals meet narrowly on 
the median line behind the thickened posterior crest of the parietal, to 
which they are closely joined. 
The parietals are much constricted between the supratemporal fossae, 
and present at the centre a high, thin median crest which at the posterior 
end rises to the height of the superior squamosal border, where it suddenly 
widens out and is extensively joined with the squamosals laterally. At 
the centre on the anterior end the parietal sends forward a tongue of bone 
that separates the frontals on the median line for fully one-half their total 
length. Ventrally, within the supratemporal fossae, they join the alisphe- 
noid and presumably the prootic bones by a nearly horizontal suture 
(Figure 8 C). 
“The orbital opening is narrowly elliptical, with its longer diameter 
directed obliquely downward and forward. It is more than twice as long 
as wide. The lateral temporal fossa is larger than the orbit, and is also 
longer than wide with a similar obliquity of length.” 
The quadrate, as in all the Lambeosaurinae, is relatively short, but 
presents no other unusual features. 
The quadratojugal appears distinctive in having its inferior border 
concavely notched. That this is not a feature of the individual is shown 
by the presence of a similar notch in this bone in a third specimen, No. 
8502, in the collections of the Geological Survey, Canada. This border in 
specimen No. 351 is missing. 
The jugal shows no specially distinctive features. The lachrymal is 
very greatly reduced as in all the members of this sub-family. It is especi- 
ally long and attenuated, measuring 133 mm. in length. It barely separ- 
ates the forward end of the jugal from being directly in contact with the 
premaxillary. Within the border of the orbit it is perforated by a large 
lachrymal foramen. The lachrymal forms the greater part of the anterior 
border of the orbital rim. 
The maxilla is relatively small and slender and contains 39 vertical 
rows of teeth. It is slightly less than two times as long as high. On the 
side of the maxillary below its union with the jugal there are five foramina 
in a line, the three median ones being of good size. In front of the jugal 
articulation the maxillary has an extensive union with the under surface 
of the premaxillary by a long but wide, thin, oblique process that strongly 
overhangs the internal side of the dental magazine. Between this process 
and the higher external maxillary process that passes up in front and 
behind the jugal is a large foramen which passes longitudinally through 
