180 MR. ST. G. 5IIVAET ON THE .SKELETON OF THE PRIMATES. 



rior in position, and presents a more or less marked and depressed triangular surface 

 (PI. XXXVII. fig. 3, between p and r), towards the sternal end of which there is 

 generally a nutrient foramen. This triangular surface is bounded inferiorly and poste- 

 riorly by a more or less marked ridge and roughened tract (PI. XXXVII. hg. 3 r), 

 doubtless answering to the rough surface serving for the attachment of the costo-clavicular 

 ligament in Man. Superiorly and anteriorly the surface is bounded by the much more 

 faintly marked ridge already mentioned, which, no doubt, gives origm to the j^ectoralis 

 major (PL XXXVII. fig. 1;^). 



The thu-d, or inferior surface, does not, as has been said, reacli the sternal end of 

 the bone, but terminates at a point about an inch and a half from that extremity. 

 The first and second surfaces (which are separated from each other behind and below 

 by the third surface for the outer four-fifths of the bone) come into juxtaposition, 

 behind as well as in front, at the point where this third or inferior surface has its 

 sternal termination. This last-mentioned surface is more or less concave till near the 

 acromial end of the bone, where, in adults, it is very rough. There is a very large 

 tubercle at the posterior margin of this surface (PI. XXXVII. figs. 2 and 3 c), serving 

 for the attachment of the conoid portion of the coraco-clavicular ligament, immediately 

 in front of which tubercle there is sometimes a very conspicuous nutrient foramen. 

 The line for the trapezoid portion of the same ligament is generally very prominent 

 (PL XXXVII. fig. 3 f) ; and behind and external to it there is sometimes' a small, yet 

 marked fossa; but the concavity beneath the acromial end of the bone is never so 

 marked as it often is in Troglodytes-. 



The acromial end of the bone is very little expanded in Slinia ; and in this tlie Orang 

 presents a marked contrast to the Gorilla ; and it also differs from Troglodytes in the 

 presence of the second or mainly anterior surface, with its strongly marked ridge above, 

 in the great roughness of the inferior surface of the acromial end of the bone, and in its 

 generally elongated sternal extremity. 



If the Orang be compared with Man, it will be seen that his clavicle would resemble 

 the Orang's, if it were much straightened, the sternal end compressed, and the front 

 edge, towards the acromial end, widened out into a concave surface surmounted by a 

 prominent ridge, the expansion of the acromial end restricted, but the tubercle for the 

 conoid ligament considerably enlarged. 



Humerus. (Plate XXXVI.) 



This bone is of great size in the Orang, but nevertheless is not, as in Man and Troglo- 

 dytes, the longest bone of the arm, being always exceeded in length by the ulna, and 

 sometimes by the radius also. 



As in the Gorilla, it exceeds three-fifths the length of the spine measured from the 



' E. g. in Nos. ^ A and 3 C in the British Museum. 



'' See skeleton of a Gorilla, No. 1011 I, in the British Museum. 



