82 



the heaviness of that bone. As a whole the zygomatic arch 

 is stronger, and probably shorter, than in U. leidianum. 



The occipital condyles are proportionately rather small ; 

 they are placed on a long neck and project downwards. 

 They are strongly convex from above downwards, but 

 scarcely at all so from side to side. The internal border is 

 slightly emarginate. 



The dorsal vertebra are of about the same proportionate 

 length as in U. leidianum, but are higher and wider ; and the 

 centra are sub-circular in section, slightly contracted in the 

 middle. The costal surfaces are wide and deep, and verti- 

 cally oval in shape ; they are placed partly on the centra and 

 partly on the neurapophyses. The transverse processes are 

 short, stout, and tuberous, and raised high above the cen- 

 trum. There is a deep notch at the posterior edge of this 

 process, at its junction with the neurapophysis. The neura- 

 pophyses are trihedral, somewhat low, and very stout, form- 

 ing a wide neural canal. 



The ulna (Plate VII. Fig. 2) is thick, with a long and rugose 

 olecranon. The shaft is long and stout ; it shows a distinct 

 medullary cavity. The distal end is small, and shows a low, 

 heavy, styloid process. 



A metacarpal resembles the corresponding bone in Dinoce- 

 ras, but is rounder and less rugose. There are two faces for 

 carpal articulations, which meet at an open angle. 



Measurements. 



M. 



Breadth over nasal tuberosities -132 



Length of nasal tip (anterior to tuberosities) -033 



Circumference of maxillary projection near the tip -208 



Vertical diameter of squamosal -058 



Transverse diameter of ditto at malar articulation -045 



Length of centrum of dorsal vertebrae -070 



Height of ditto -083 



Breadth of ditto below costal surfaces -097 



Breadth of pedicle -058 



Length of transverse process -056 



Extreme breadth of transverse process -061 



Found at Henry's Fork. 



UlNTATHERIUM ROBUSTUM. Leidy. 

 Cont. to Ext. Vert. Faun., p. 96. 



A fragmentary skeleton from Henry's Fork. 



