302 THE OSTEOLOGY OF ELOTHERIUM. 



Measuremen ts. 



Scapula, glenoid cavity, transverse diameter- ■••• 050 



Humerus, length 405 



Humerus, width of proximal end =..=.... 132 



Humerus, thickness of proximal end 128* 



Humerus, width of distal end 095 



Radius, length .350 



Radius, width of proximal end. 074 



Radius, width of distal end 062 



Ulna, length -143 



Ulna, length of olecranon fr. coronoid process 103 



Ulna, width of distal end 037 



VII. The Manus (PL XVIII, Fig. 11), 



The principal facts of the structure of the fore foot have already been determined by 

 Kowalevsky, but the material now at command permits a more complete account to be 

 given. Certain differences also which obtain between the European and American repre- 

 sentatives of the genus should not be passed over without mention. 



The corpus of Elotherium is a curious one in many ways, and while modified to suit 

 the didactyl condition of the foot, by the reduction of the lateral and enlargement bf 

 the median elements, it has yet retained many of its primitive characteristics. 



The scaphoid is high and thick in the dorso-palmar direction, but very narrow trans- 

 versely. The dorsal and internal (i. <■., radial) surfaces of the bone are very rugose, and 

 n the palmar border, which is the narrowest part of the scaphoid, is a blunt and massive 

 mammillary process. The articular surface for the radius is of unusual shape. It is 

 divided into (wo parts, an antero-external and a postero-internal ; the latter is much the 

 larger and is saddle-shaped, convex transversely and concave in the dorso-palmar 

 direction, while the former is convex and descends steeply toward the ulnar side. These 

 two parts of the articular surface are continuous, but they meet at nearly a right angle, 

 and their junction forms a ridge, which is the highest point of the scaphoid. On the 

 ulnar side are three facets for the lunar : the largesl one is proximal and dorsal, and is 

 continuous with the surface for the radius, which it meets at almost a right angle; this 

 facet is very oblique and presents distally as well as laterally, the scaphoid here forming 

 a projection which extends over the lunar. The second lunar facet is dorsal and distal in 

 position ; it is small, nearly plane, and not very distinctly separated from the facet for 

 the magnum. The third lunar facet is distal and palmar, and is placed upon the ulnar side 

 of the mammillary process already mentioned; it is of oval shape and nearly flat. The 

 contact between the scaphoid and the lunar is confined to these three points, and as the 



* Somewhat reduced by crushing. 



o 



