31 
A careful comparison of the maxilla with those of the two crested skulls 
referred by Lambe to Stephanosaurns discloses structural differences 
important enough to show that they pertain not only to distinct genera 
but to distinct sub-families. The maxilla in its large size, massiveness, 
more robust teeth, greater horizontal distance between forward end of 
jugal articulation and border of infraorbital foramen, and more massive 
and bluntly truncated anterior extremity, agrees so closely with the maxilla 
of the type specimen of Kritosaurus notabilis (Lambe) that I have little 
hesitation in referring it to that genus. These differences and resemblances 
in the compared maxillae are graphically shown in the following table: 
Comparative Measurements of Maxillm 
Referred 
Kritosaurus 
maxilla. 
No. 362, 
G.S.C. 
Krito- 
saurus 
notabilis, 
type, 
No. 2278, 
G.S.C. 
Referred 
Stephano- 
saurus 
skull, 
No. 2869, 
G.S.C. 
Referred 
Stephano- 
saurus 
skull. 
No. 351, 
G.S.C. 
Mm. 
Mm. 1 
Mm. 
Mm. 
Greatest length of maxillary 
360 
395 
286 
325 
Length of dental series 
316 
252 
290- 
Distance between anterior end of jugal 
and infraorbital foramen 
65 
80 
20 
30 
Horizontal distance between border of 
infraorbital foramen and anterior tip 
of maxillary 
90 
100 
105 
125 
The identification of the maxillary with the genus Kritosaurus leaves 
only the left dentary of the typical specimens of the genus Stephanosaurns 
to be considered. Comparison of the dentaries of the referred skulls with 
this bone shows several important differences, although the damaged 
condition of the anterior edentulous and symphysial portions of the typical 
dentary renders close comparisons exceedingly difficult. Lambe has given 
a very complete description 2 of this bone, but failed to point out its imper- 
fections, many of which are not indicated in the illustrations. The 
coronoid process is shown too erect and too long, possibly because there is 
no bony connexion between the spatulate top and the basal portion and 
the restored connexion has been unduly lengthened. The preparator has 
also erred in the angulation of this process in relation to the main body 
of the bone, in directing it outward at the top at too great an angle away 
from the dental series. In the original illustrations the front of the dental 
magazine is correctly shown as missing, but the edentulous border in front 
of the teeth and much of the symphysial border are lacking. Were these 
borders present the contours would obviously be very unlike the narrow 
pointed extremity shown in Lambe’s figures. It is also obvious that the 
edentulous portion of this bone is considerably more elongate and narrowly 
truncate than in either of the dentaries belonging to the skulls which 
Lambe referred to Stephanosaurus. Attention should also be drawn to 
Estimated. 
*Contr. to Can. Pal., vol. 3, pt. II, 1903, pp. 73, 74, PI. Ill, fig. 1, and PI. IV, fig. 1. 
68675 — 3 * * 
