264 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 92 
fibular ligament lying beneath the broad insertion tendon of the 
rectus femoris in which the patella tibialis develops. 
FAMILY RELATIONSHIPS 
Aside from the unique dentition, the skeletal features of Poly- 
glyphanodon are essentially iguanid in character. The general struc- 
ture of the skull, procoelous vertebrae with tapering centra, the pres- 
ence of zygosphene-zygantrum articulations on the vertebrae, absence 
of osteoderms, and foot structure are all features in accord with the 
Tguanidae. 
Omitting consideration of the teeth and the method of implanta- 
tion, none of the other structural differences observed, whether taken 
singly or collectively, are greater than exist between living genera 
now accepted by herpetologists as true members of the Iguanidae. 
The heterodont teeth implanted in shallow sockets and coossified with 
them, with no indication of replacement teeth, and the presence of a 
single emargination in the coracocid suggests agamid affinities, but 
the presence of a well-developed splenial covering most of the Meck- 
elian groove is quite unlike the condition found in the agamid lower 
jaw, where the splenial bone is small or wanting, and the groove is 
open. In view of the fundamental differences displayed by the den- 
tition, it is my conclusion that Polyglyphanodon cannot be logically 
included in the family Iguanidae, all of which have a homodont 
dentition with a pleurodont type of insertion in the jaws. 
The zygosphenes, united premaxillae, and a well-developed splenial 
and angular showing but little on the outside of the jaw seem to 
exclude Polyglyphanodon from the Agamidae. 
In view of the above facts I now propose the new family Poly- 
glyphanodontidae for the reception of this new form, which appears 
to be a true member of the Ascalabota division of the Sauria. 
RESTORATION OF THH SKELETON 
The restoration of the skeleton of Polyglyphanodon sternbergi 
shown in plate 26 is a composite based upon a careful study of all 
available materials. All are from a restricted locality, and with one 
exception all are of appreximately the same size. Although parts 
of the skeleton have been illustrated from different individuals these 
have been coordinated as to proportions following the evidence of 
the excellent skeleton shown in plate 25. 
The skull, lower jaws, sacrum, pelvis, and hind legs were drawn 
from the type, U.S.N.M. No. 15477. The presacral part of the ver- 
tebral column is for the most part based on specimen U.S.N.M. No. 
15566, supplemented, of course, by the complete series of the articu- 
