THORAX AND RIBS. 37 



regular. The external face is a little excavated above, smooth at its middle, 

 and below is divided into two parts by a deep groove, which bisects the 

 external angle. The internal face has a somewhat posterior aspect, is 

 excavated above and flattened below. It terminates inferiorly in a rough 

 surface for liganientary attachment. 



The inferior articulating surface of the ulna is connected with three 

 bones of the superior range of the carpus (Plate XL A), viz. principally 

 below, with the cuneiforme, behind with the pisiforme, internally with the 

 semi-lunare, with which it articulates to a very small extent. . 



The length of the ulna from the summit of the olecranon to the lowest 

 point of the inferior extremity is thirty-four inches. The circumference of 

 the neck of the inferior head is twenty inches; that of the head of the 

 bone is thirty-eight inches, of the centre of the shaft fourteen. 



Tue Haxd. — The fore-foot, or hand (Plates XL and XII.), is of great Theiiand. 

 size, the bones measuring nearly two feet across. Compared with that of 

 the elephant, the hand is less perpendicular, presenting rather a superior 

 and inferior than anterior and posterior surface. The superior surface is 

 generally convex, regularly so over the carpus, but less so over the fingers. 

 The inferior surface is concave, very irregular, presenting a considerable 

 number of eminences, formed by the bones of the carpus, metacarpus, and 

 the sesamoids. The scaphoides, on the inner part of the wrist, and the 

 pisiforme and unciforme, on the outer, form the most remarkable of these 

 eminences. 



The Wrist (Plates XL and XII.) — The carpus has eight bones in two TheAVmt. 

 ranges. In the upper or proximal range are the scaphoides, semi-lunare, 

 cuneiforme, and pisiforme; in the lower or distal range are the trapezium, 

 trapezoides, os magnum, and unciforme. 



