200 MR. ST. G. MIVART ON THE SKELETON OF THE PRIMATES. 
The trochanteric fossa is deeper than in the Gorilla, but, as also in Man, it is less 
deep than in the Chimpanzee. The intertrochanteric line behind is rather more 
sharply and strongly prominent than in any of the higher forms (Pl. XL. fig. 2 d). 
The head of the femur is very large, especially as compared with that of the 
Chimpanzee, though absolutely exceeded by that of Man, and also by that of the 
Gorilla when of large size. It is sharply defined by a prominent border all round, 
oxcent sometimes for a short space near the intertrochanteric fossa (Pl. XL. figs. 1, 
2, 5, 4, 6, 7a). 
The sharp projection of its anterior margin is more like what exists in 7roglodytes 
than in the general structure of Man. 
It is commonly asserted that the ligamentum teres is absent in. the Orang, as also 
the pit for its reception on the head of the femur’. I find no trace of the latter in 
either femur of any specimen, with one exception’; but in that. exceptional specimen 
each femur (Pl. XL. fig. 77) exhibits a small but distinct depression on its head in 
the place occupied in other forms by the pit for the round ligament. This absence 
has not, as far as I am aware, been noticed in Man or the Chimpanzee ; but. in the 
Gorilla I have sometimes been unable to detect any trace of such a fossa on the head 
of the femur*. It may therefore be the case that this Hgament is peneeneny absent 
in the Gorilla, and occasionally present in the Orang. { 
The rotular surface (Pl. XL. fig. 10) does not,.as in oe, project higher-on. the 
peroneal than on the tibial side, but more resembles in this respect that of the Gorilla 
than even that of the Chimpanzee; it extends, however, further up the shaft, and 
has its superior margin more acutely convex than in 7roglodytes. It is even less 
concaye transversely than in the Gorilla and Chimpanzee, and therefore still more 
widely differs in this respect from the rotular-surface of Man than do the corresponding 
parts in them. 
The external condyloid articular surface is somewhat narrower than is the internal 
one, but the difference is less than in Z’roglodytes' (Pl. XL. fig. 5m & n). 
The breadth of the intercondyloid fossa (which, as in the Gorilla, is generally 
shallower than in Man) is about equal at its anterior and posterior ends, 
As in Vroglodytes, the whole distal surface of the bone is broader in proportion to 
its antero-posterior extent than in Man’, and the external condyle: projects backwards 
less than the internal one does—the external one being, as in that genus, the shorter 
one from before backwards, instead of rather the longer~ of the two as m Man* 
(Pl. XL. fig. 5m & n). ; 
‘ Owen, Trans. Zool. Soc. vol. i, p. 365, and De Blainville, ‘ Ostéographie,’ Primates, Pithecus, p. 31. - 
? No. 37 in the osteological collection of the British Museum. 
’ E.g. in all four femora of the specimens Nos. 5179 a and 5179 8 in the Museum of the Royal College of 
Surgeons. * Owen, Trans, Zool. Soe. vol. v. p. 16, plate 7. fig. 3. 
° Owen, loc. cit. p. 16, plate 7. fig. 3. 5 Owen, loc. cit. p. 18. 
