xv, i Shufeldt: The Monkey-eating Eagle 49 
soaetus pelagians) , found in Kamchatka and Japan as well as in 
Korea, may be a bigger bird in some respects. Sharpe included 
the Old World vultures in the true raptorial group. In the 
genera Vultur and Serpentarius there are some big species the 
comparative weights and proportions of which have never been 
taken for a series of living specimens or compared with the cor- 
responding data on Pithecophaga jefferyi. 
I have never compared the wedge-tailed eagle, Uroaetus audax 
Lath., of Australia and Tasmania, with our present subject; but 
I am inclined to believe that it is not so large a bird. 
The radial crest of the humerus of the white-headed eagle of 
the United States is also triangular in outline; while in Aquila 
chrysaetos canadensis this feature of the bone under considera- 
tion is not so lofty and, while triangular in general outline, it 
extends very much farther down the shaft of the bone. Here, 
too, the osseous emargination of the pneumatic fossa is broader 
and more extensive, thus closing in upon the true cavity, though 
in no other way diminishing its capacity. 
The bearded vulture of Europe has a humerus fully one-third 
larger than that bone in Pithecophaga, and its characters are 
very similar, the most striking departure being the shallow pneu- 
matic fossa in the former species, with all of its foramina 
merged into one subcircular foramen. 
In the antibrachium of Pithecophaga both the ulna and the 
radius exhibit some degree of curvature between proximal and 
distal extremities. Air gains access to their interiors through 
minute foramina at the proximal and the distal end of each; at 
the latter situation they articulate in the usual manner with the 
radiaie and the ulnare of the carpus, bones that here present 
the avian characters usually seen among the eagles. The 
radius has an extreme length of some 20.5 centimeters, and the 
ulna is about 2 centimeters longer than this. The latter bone 
has a double row of osseous papillse down its cylindrical shaft; 
these, as in other birds, are for the attachment of the quill butts 
of the secondary feathers of the wing. There are ten in each 
row, and all, to the last pair at either end, are opposite each 
other. The anterior third of the radius is subcylindrical in form, 
while the remainder of the shaft is trihedral on section. Its 
“radial tuberosity” is concaved in the center, with the inner 
margin sharp. Our harpy eagle skeleton lacks the bones of the 
forearm and manus. 
Thallasoaetus pelagicus has the radius and the ulna much 
longer than the monkey-eating eagle, and each is markedly 
166316 4 
