292 
AVES. 
Width of tbe same..... 0.0080 
Length of tbe scapular facet.... 0. 0060 
Width of tbe same. 0.0040 
Transverse extent of the distal articular fossa of the coracoid. 0. 0150 
Width of the same... 0.0080 
Transverse diameter of the shaft of the coracoid just above the posterior distal 
muscular area....... 0. 0130 
Length of the scapular facet of the furcula . 0.0100 
Width of the furcula at the lower end of the same... 0, 0140 
Of the pelvic arch, only the ischia remain; that of the right side is the 
best preserved. It is smaller than that of the Golden Eagle, and but little 
less robust; it differs remarkably from that of that species, in that the 
sacro-ischiatic foramen extends a considerable distance posteriorly to the 
obturator foramen, while in the latter their posterior borders are in the 
same diagonal line. The ridge of origin of the ischio-femoral muscles is well 
developed, running parallel with the inferior border. 
Measurements of the isehinm. 
Length... 
Depth at the end of the obturator foramen. 
Depth at the end of the sacro-ischiatic foramen. 
M. 
0. 0410 
0. 005 
0. 009 
Of the wing-parts, all the elements excepting the radius and some of 
the phalanges are present. The proximal end of the humerus is the largest 
of those of the long bones. It is slightly concave anteriorly, and the 
external crest is thick and recurved backward, and terminates in a hook¬ 
like truncate tuberosity directed backward and inward. The condyle or 
head is lenticular in section, with the anterior border flat, and the extremities 
acuminate, the outer separated from the external tuberosity by a deep notch. 
Tlfe proximal part of the shaft is convex behind, and has a shallow groove 
on the external side of the median ridge, between which and the external 
border the section is slightly concave. The distal end resembles the cor¬ 
responding portion in the Golden Eagle, but the anterior supracondylar fossa 
is deeper and witli better-defined lateral borders. On the anterior face, 
the muscular ridges are well defined as three longitudinal raised lines, while 
the surface is almost uniform in the A. chrysaetos. Thus, there is a wide, 
open groove above the internal tuberosity in V. timhrosns, which is but little 
defined in the former species. The external tuberosity is more protuberant 
