94 THE AMERICAN NATURALIST. 
almost as great as that in the rhinoceros. In the still earlier 
forms, such as Pantolambda, of the basal Eocene, the angula- 
tion is. almost equal to that in the Creodonta, from which this 
entire order sprang. 
There is no doubt, tarelor. that in my restoration of Loxo- 
lophodon, as well as in Professor Cope’s restoration of the 
same animal, which was published later, the fore limb is some- 
what too straight. On the other hand, Professor Marsh seems 
to have given the limb too much flexure in his restoration of 
Uintatherium (Tinoceras) ingens, a slightly older type than 
Loxolophodon. 
The more vertical position of the limb is secondary, it is 
observed, in all large quadrupeds. In the Titanotheres it has 
not proceeded so far as in the above types of mammals. Among 
reptiles it is observed in the heavy quadrupedal Sauropoda. 
The straightening of the limb is an adaptation designed to 
transmit the increasing weight through a vertical shaft. Cor- 
related with it are the shifting of the facets into the direct line of 
pressure and the alteration of their planes from an oblique to a 
right or horizontal angle with relation to the vertical shaft. 
