198 MR. ST. G. MIVART ON THE SKELETON OF THE PRIMATES. 
when the outer surface of the ilium (Pl. XX XIX. fig. 1) is opposite the observer, 
instead of almost the whole of its cavity being so, as is the case in Man’. 
Femur. (Plate XL. figs. 1-7.) 
This bone is exceedingly short in the Orang, both absolutely and relatively, as com- 
pared with Man and the Gorilla. 
In Zroglodytes it is more than half the length of the spine (measured as before), 
and in Man it is more than three-fifths of it; in the Orang, however, I find it less 
than half. 
As compared with the length of the os innominatum the femur is somewhat longer in 
the Orang than in 7'’roglodytes—as it is decidedly the longer of the two; still the pro- 
portion very much more resembles that existing in the last-named genus than Man’s, 
as his femur is about double the length of his os innominatum. 
A comparison of the femur with the humerus shows a greater difference from Man 
than that presented in 7’roglodytes, though even in the Chimpanzee the femur is slightly 
the shorter of the two, instead of very much the longer, as in Man. 
When the femur of the Orang is made to rest with both condyles on a horizontal 
surface, and placed as nearly as may be in a vertical position, the bone does not incline 
outwards (peronead) superiorly so much as does that of Man when similarly placed ; it 
does so, however, in a slightly greater degree than is the case in 7'roglodytes?. 
The body or shaft of the bone differs much from that of the femur of Man, and 
greatly resembles that of Zroglodytes. This is the case as regards the absence of a 
strongly projecting linea aspera, the less transverse convexity of the anterior surface, 
the much greater antero-posterior compression of the bone, and its less degree of cur- 
vature convex forwards, the shaft being even straighter than in the Gorilla (Pl. XL. 
figs. 3 & 4). It also differs from Man’s, and agrees with that of Z'roglodytes, in the 
large proportion borne by the transverse diameter to the length—though in this 
respect it resembles the Chimpanzee, it being more slender than in the Gorilla. The 
lateral expansion downwards of the shaft, though more gradual than in Man, is much 
Jess so than in the Gorilla; and the external margin of the same is more concave than 
in Zroglodytes, and approximates, therefore, in its outline to Man’s. 
In the Orang, as in the Gorilla and Chimpanzee, the external and internal surfaces 
of the shaft are much narrower from before backwards than in Man. ‘This arises from 
the non-projection of the linea aspera, which seems to be, as it were, flattened out in 
both Simia and Troglodytes, though least so in the Gorilla. 
The anterior intertrochanteric line (Pl. XL. fig. 1 ¢) is continued into the spiral line 
(Pl. XL. figs. 2 & 37), and can be followed downwards to the entocondyloid prominence 
» Owen, Trans. Zool. Soe. vol. v. p. 14. 
2 There is a certain amount of individual variation in this respect; in the specimen No. 3¢ in the British 
Museum, the inclination is considerable, approaching that of Man. 
