29 
Height at midlength 180 
Length of dental magazine 368 
Breadth across alveolar borders at midlength 24 
Breadth at lower edge of surface for attachment of jugal 70 
Maximum protrusion of teeth below alveolar border at midlength of dental maga- 
zine 33 
Jugal. (J.). Figures 8, 4, 14- This element is long, thin, and 
plate-like, with an obtusely angulated lower outline, and deep indentations 
above forming the lower boundaries of the orbital and infratemporal 
openings. Its extreme length to its maximum depth is in about the 
proportion of 6 to 5. It connects antero-superiorly with the lachrymal 
and palatine, anteriorly with the maxillary, posteriorly with the quadrato- 
jugal and the quadrate, and superiorly considerably behind its midlength 
with the postfrontal by means of its ascending process behind the orbit. 
Externally it interjects a forwardly directed angulation of the front border 
Figure 14. Left jugal of Edmontosaurus, Cat. No. 2289; internal aspect; | natural 
size. I, surface of contact with lachrymal; mx, with maxillary; pal, with palatine; q, 
with quadrate; qj, with quadra to-jugal; pof, with postfrontal. 
between the lower end of the lachrymal and the highest point of the max- 
illary to the lower edge of the premaxillary limb. The anterior end of 
the jugal covers the maxilla behind the latter’s midlength in an extensive 
rugose surface of contact. Antero-superiorly it is grooved in a longitudinal 
direction, more deeply near the orbit than toward the front, to receive 
the lower edge of the lachrymal. The superior border is deeply emarginated 
by the narrow, somewhat similarly curved, downwardly and forwardly 
directed lower ends of the orbit and infratemporal fossa. The ascending 
8329—3 
