33 
Measurements of Quadrate of Edmontosaurus {paratype, Cat. N^o. 2289). 
Mm. 
Len^h of quadrate in a straight line 420 
Maximum breadth (antero-posterior) of external smdace above contact with quad- 
rato-jugal 93 
Horizontal distance from external surface to greatest extension inward of flange 
connecting with pterygoid 145 
Figure 17. Left pterygoid of Edmontosaurus, Cat. No. 2289; \ natural size. A, exter- 
nal aspect; B, internal aspect; bsp, surface of contact with process of basisphenoid; 
ept, with ectopterygoid;mx, with maxillary; pal, with palatine; g, with quadrate. 
Pterygoid. (Pt.). Figures 3, 13, and 17. The pterygoid is a thin 
bone of complicated shape in contact with the quadrate, basisphenoid, 
palatine, maxillary, and ectopterygoid. It probably also effects a junction 
supero-anteriorly with the vomer. 
