50 
Philippine Journal of Science 
1919 
slenderer. We are also to notice that the papillse on the shaft 
of the latter are closer together. Ten pairs of them appear to 
be present, and the ulna in this bird has an extreme length of 
24.3 centimeters. 
America’s golden eagle departs from others examined, in that 
the humerus and the femur are the only pneumatic bones of the 
pelvic and pectoral limbs. 
Unfortunately, I have not at hand the skeleton of manus either 
in the case of the harpy or of the species here being osteologically 
considered; so that a description of these parts will have to be 
undertaken by someone else, when such material fails into the 
hands of science. Very likely, in other published papers of 
mine, descriptions of these parts of the skeleton in other species 
of eagles will be found, either of fossil or existing species. 
The pelvic limb . — Plate VII, fig. 1 ; and Plates IX, X, and XI. 
Pithecophaga jefferyi possesses a big femur, which is permeated 
by air in all of its parts. There is an extensive group of pneu- 
matic foramina in the deep popliteal concavity, and another 
large opening on the proximal end of the bone anteriorly, at the 
termination of the trochanter major; it is bounded internally 
by the linea aspera. Caput femoris is sessile, with an extensive 
pit for the ligamentum teres. The summit is smooth and convex 
from before backward, and concave from head to the trochanter, 
which latter rises above the summit of the bone. It is very broad 
and rough on its external surface. Passing to the shaft, we 
find that to be very stout and uniformly arched, the convexity 
being in front. For its middle third it is subcylindrical in form 
and very slightly roughened throughout. 
Distally the condyles of this femur are enormous with very 
prominent articular surfaces. The side of the inner condyle is, 
for the most part, flat and smooth, while the outer one is slightly 
roughened and presents a conspicuous tuberosity. As usual, this 
condyle is vertically divided posteriorly, in that it may articulate 
with the head of the fibula of the leg. This femur has an extreme 
length of about 13.2 centimeters, or 2 millimeters more than the 
length of the femur of a harpy eagle; but the little that the 
harpy lacks in length in this bone it amply makes up in stout- 
ness ; and, apart from this general stoutness, there is no specific 
difference worthy of notice or description. 
The femur of the golden eagle - is of about the same length as 
the two just noticed ; but it is a far slenderer bone, with the ellip- 
tical pneumatic foramen at its proximal end very conspicuous, 
and the muscular lines on the shaft are likewise so. The poplit- 
