82: GEOLOGICAL SURVEY OF THE TERRITORIES. 
These measurements show us that among the Cathartide, the Condor 
of our western country possesses the greatest extent of wing, although 
the South American one (Sarcorhamphus) has the longest legs; the same — 
condition is also seen to exist between Cathartes aura and Catharista 
atrata. Also, in comparing C. aura with N. perenopterus, we observe that 
although the measurements of the seg- 
ments of the pectoral limb are very nearly 
alike, the latter bird has a longer tarso- 
, netatarsus in comparison, even where the 
femur and tibia are nearly as in the first; 
here again we find in this Old World 
Vulture a balance among the segments 
of this extremity that similates the Fal- 
conide. 
The femur is so bent that a longitudinal — 
line drawn along its anterior surface is 
convex outwards, the greatest curvature 
existing at the junction of middle and 
lower thirds of shaft. A similar line 
drawn down its inner aspect is found to 
be concave. . 
The upper surface of the semi-globular 
head is in the same horizontal plane with 
the extensive articular facet at the sum- 
mit of the bone for the antitrochanter of 
the pelvis, while above this rises the 
broad and prominent ridge of the great 
trochanter; below and to the outer side of 
which we find the pneumatic foramen (C. 
aura) or foramina (Pseudogryphus), for 
generally the species show more than one. 
The femoral head is eminently sessile 
with the shaft, and presents for examina- 
tion above an extensive though single 
excavation for the ligamentum teres. Be- 
low the characters we have just enumer- 
ated as pertaining to the proximal ex- 
tremity of the bone, the shaft rapidly be- 
comes subcylindrical, to dilate trans- 
versely at its distal or condylar end in the 
usual way. Near the middle of the shaft 
behind we observe the medullary orifice, 
and the ordinary muscular lines are tol- 
erably well produced. 
The rotular channel on the anterior 
aspect is moderately deep, rather wide, 
Anterior viow of right femur from Pseudo. 20.4 of nearly the same width throughout; 
gryphus californianus ; life-size. it passes beneath into a shallow, inter- 
condyloid notch. In the popliteal depression, above the condyles behind, 
a deep pit exists; a few foramina are found at the bottom of it in Cathar- 
ista atrata that may be pneumatic. The fibular cleft at the back of the 
external condyle is very decided, the inner half formed by it being pro- 
duced well backwards in all of the Cathartide, as a prominent process to 
be applied to the internal aspect of the fibula in the articulated limb. 
Slight depressions are found, one on either side, in the broad lateral 
surfaces of the condyles, intended for ligamentous insertion. If a plane 
