254 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 92 
low notch, as shown in figure 29, B. The interclavicle of U.S.N.M. 
No. 15566 differs in having a V-shaped notch that extends farther 
posteriorly into the bone. (Compare A and B, fig. 29.) On the ven- 
tral surface a sharp median keel develops at the posterior edge of the 
notch, continuing backward for a short distance before merging into 
the transversely rounded surface of this side. The posterior fourth 
of the bar is slightly spatulate in outline, terminating in a bluntly 
pointed end. Viewed from the side, this bone in front of the cross 
bar turns strongly upward. ’ 
Measurements of interclavicle (in millimeters) 
No. 15559 No. 15568 
Greatest, length sa. 2 to 25 hs es 54 55 
Greatest width;anterior ends22222 22) s. Seia aS ee eee 9.0 al ists3 
rac ule 
Ficure 30.—Left humerus of Polyglyphanodon sternbergi Gilmore, U.S.N.M., No. 15566, 
natural size: A, Anterior view; B, posterior view. d, Deltoid ridge; rac, radial condyle; 
ulc, ulnar condyle. 
FORE LIMB 
Humerus.—iIn all there are 11 humeri preserved with the several 
specimens, six of which are nearly perfect. For purposes of illustration 
and description the left humerus of specimen U.S.N.M. No. 15566 is 
selected as being the most perfect, as shown in figure 30. 
The humerus is of the “old-fashioned” reptilian type, broadly ex- 
panded at each extremity and joined by a slender shaft. The planes 
of the two ends meet each other at a slight angle, that of the proximal 
turned outward from the horizontal. The ends are more expanded 
than in either Jguana or Cyclura, and the shaft is relatively shorter 
