204 _ MR. ST. G. MIVART ON THE SKELETON OF THE PRIMATES. 
Man, and, though slightly concave, has not the marked depression existing in 
Troglodytes. 
As in the Gorilla and Chimpanzee, the outer side of the head has a very marked 
prominence (Pl. XLI. figs. 1, 3, & 6) for the long external lateral ligament and the 
tendon of the biceps. There is no styloid process, that eminence being more completely 
absent than in Troglodytes. 
As in the last-named genus, so also in Simia, one single anterior ridge appears to 
answer to both the external and internal anterior lines of Man' (Pl. XLI. fig. 1w). - 
This ridge descends along the anterior surface of the bone, and bifurcates very near its 
inferior end. 
The margin answering to the posterior external one of Man (Pl. XLI. fig. 3v) is 
quite indistinct, except at the lower part of the bone. It extends obliquely, from the 
inner side of the posterior surface of the malleolus, in an upward and outward direction, 
over the posterior surface of the shaft of the fibula, for a greater or less distance towards 
its head. 
There is in the Orang, as in Man and 7roglodytes, a posterior internal ridge (Pl. XLI. 
figs. 3 & 7 w) which runs obliquely downwards and forwards from the inner aspect of 
the head of the fibula, and joins the anterior margin before mentioned, 
The medullary foramen (opening distad as in Man and Tvoglodytes) is placed more or 
less near to the middle of the bone (from above downwards) below and rather behind 
the posterior internal ridge (Pl. XLI. figs. 3 & 7 y). 
The contraction of the anterior surface of the fibula in Simia and Troglodytes, through 
the coalescence as it were of the external and internal anterior margins of that bone in 
Man, is more than compensated for by the wide surface for muscular attachment 
offered by the interosseous ligament. 
As in Troglodytes, the peroneal malleolus is shorter and blunter than in ietas and does 
not descend below the tibial one’ (Pl. XLI. fig. 1). 
Pes. (Plates XLI. fig. 12, & XLIII.) 
The absolute length of this segment in the Orang exceeds that of the higher forms ; 
as also its length as compared with the spine, with the rest of the pelvic limb, and 
with the tibia. 
The proportion borne by the length of the pes to that of the manus is, as also in 
Troglodytes, much less than in Man. 
Tarsus. 
Unlike the carpus, the tarsus consists of the same number of bones as in the higher 
' The fibula of Man is very lucidly described by Mr, A. T. Norton, in his convenient and carefully prepared 
‘ Osteology for Students,’ recently published, ? Owen, Trans. Zool. Soc. vol. y. p. 20. 
