256 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 92 
anterior face of the olecranon. The radial border of this end is concave. 
The whole bone tapers from above downward, the shaft is flattened 
transversely, the least diameter being on the lower third. There is but 
little expansion of the distal end. The convex articular surface of this 
end continues upward to an equal extent on both the anterior and 
posterior aspects. The posterior surface is abruptly backward from 
the shaft. 
Such slight differences as are found in these bones of different 
individuals can be attributed to post-mortem causes. 
Measurements of radius and ulna (in millimeters) 
Radius Ulna 
(No. 15559) (No. 15559} 
Greatest Ven pth ies ae ES ae 41.3 48.8 
Greatest diameter of proximal end_..--~=2—~~-- === 224-2 10.0 123 
Greatest diameter, of distal end". 22: 3s ee ieee 10.5 7.4 
eastvdvameter tof: Shatter ee ae a ae 3.6 3.4 
Carpus—The complete composition of the carpus of Polygly- 
phanodon is not shown in alry of the specimens now available. The 
left carpus of the paratype, U.S.N.M. No. 15816, is probably the most 
complete, but in its present condition in the matrix as found it is quite 
impossible to differentiate fully its several elements. By a study of 
the carpal bones of all available specimens it has been possible to 
recognize the more important wrist bones. Specimen U.S.N.M. No. 
15566 has the radiale attached to the distal end of the radius, thus 
definitely identifying this element. The radiale is the second largest 
bone in the carpus. It is of irregular shape, with a thinned anterior 
border, becoming thickened posteriorly, but more especially toward the 
outer end, which projects strongly downward and backward when in 
articulated position. On the anterior ventral surface at midwidth a 
distinct flattened facet indicates the point of articulation with cen- 
trale 1. External to this facet a notch represents the facets for cen- 
trale 2. The ulnare is easily recognized on account of its blocklike 
form and the fact that it is the largest bone of the carpus. It is assumed 
that there were five carpalia, but only one, the fifth, U.S.N.M. No. 15816, 
was found in articulated position. It is asmall rounded element. The 
incomplete carpus outlined in figure 32 was drawn after that of the 
Iguana. ‘The close resemblance of the carpal bones to the homologous 
elements of the 7guana carpus leads to the conclusion that when the 
complete carpus is known it will be found to resemble closely that of the 
living form. 
Fore foot—The manus is represented by the partially articulated 
right fore foot of specimen U.S.N.M. No. 15568 and the almost com- 
plete articulated left fore foot of the paratype, U.S.N.M. No. 15816,. 
as shown in plate 25. In addition to these two articulated feet, sev- 
eral of the other available specimens had scattered portions of the 
