104 



nence, defined from the trochlea by a wide, pitted groove. Its upper part is 

 destroyed in the specimen. Its l>aclv part barely projects posterior to the 

 position of the trochlea. 



Above the distal articulation, where the bone is expanded to form the outer 

 epicondyle, it is depressed into a l:)road and unusually deep concave fossa. 



The olecranon fossa is broad and moderately deep, but is not much ex- 

 tended by the protrusion backward of the epicondyles. 



The distal articulation of the humerus presents a well-rounded capitulum 

 on the outer condyle and a broad trochlea extending from it on the inner 

 condyle. The capitulum is convex and narrows behind on a ridge separating 

 the posterior prominence of the outer epicondyle from the trochlea. The 

 trochlear groove is directed obliquely from the fossa in front of the outer epi- 

 condyle downward and inward, then backward, upward, and outward to the 

 olecranon fossa. 



The measurements of the bone are as follows : 



Inches. 



Length of the buinerus internally 20J 



Width ti'ansversely of the head 4^ 



Width of shaft at the middle from the lower part of the deltoid tract to the pos- 



tero-iiiteraal border i^ 



Thicl;ness of shaft at middle of same position 2^ 



Circumfereuce of narrowest part of shaft 9^ 



Diameter transversely of narrowest part of shaft 2g 



Diameter autero-posteriorly of narrowest part of shaft 3 



Breadth at the epicondyles , , , . - 7f 



Breadth of distal articulation 5^ 



The mutilated upper extremity of the femur, represented in Fig. 4, Plate 

 XXVI, was found by Dr. Corson, on the buttes west of Dry Creek Caflon, 

 a dozen miles from the former specimens. It is suspected to pertain to Uin- 

 tatherium, though it would ajjpear to have belonged to a larger animal, and 

 perhaps a different species, than the one to wdiich the cranium and humerus 

 are referred. The specimen has about the same si^e and form as the corre- 

 sponding part in the elephant, but the great trochanter is destroyed. The 

 length of the fragment is about 11 inches. The head is 5 inches in diameter, 

 but its surface is too much mutilated in the specimen to determine whether 

 it possessed a jtit for the attachment of a round hgament, or whether it is 

 absent as in recent proboscideans. The outer border of the shaft below the 

 position of the great trochanter is 2g inches thick. From the appearance of 



