456 THE WASATCH FAUNA. 



condyles nearly equal in proportions. The head has a peculiar shape, 

 which is also found in the Phenacodus vortmani; it is oval instead of round; 

 the long diameter crossing that of the trochanters at a very wide angle out- 

 wards and backwards. The posterior face is most flattened, and here the 

 fossa ligamenti teris forms a wide notch in the edge. The great trochanter 

 is large, and projects as far as the head, from which it is separated by a 

 deep notch. Its superior edge is transverse, terminating in an anteriorly 

 directed apex, and inclosing with the prominent posterior edge a deep 

 trochanteric fossa. Summit of great trochanter beveled obliquely out- 

 wards. The little trochanter is prominent. It commences opposite the lower 

 fundus of the trochanteric fossa, and terminates opposite the superior edge 

 of the third trochanter. The latter is above the middle of the lenyth of the 

 femur, that point marking the inferior edge of its truncate extremity. It is 

 well-developed, and its truncate edge has a lenticular outline. The borders 

 of the latter are prominent, so that the anterior and posterior sides are 

 moderately concave. The internal side of the shaft is rather broadly 

 rounded. The external edge is angular. The rotular crests are prominent 

 and thick, and the interior is the more prominent and prolonged upwards. 

 It is not, however, swollen as in some recent Perissodactyles. At the pos- 

 terior base of the external condyle is a sliallow fossa. A much wider and 

 deeper one lies above the inner condyle and the inner half of the inter- 

 condylar fossa. The latter is wide, equaling the internal condyle in width 

 posteriorly, and is a little narrower than the external condyle. The greater 

 width of the latter is caused by the prominence of its external border, 

 which encloses with it a groove, which is very shallow except at its superior 

 termination at the superior quarter of the face. Just above and external 

 to this part of the groove is a smaller fossa. Other than this and a shallow 

 fossa of the internal side, the lateral or epicondylar fossae are not marked, 

 nor are there any between the condyle and the rotular ridge, as in Hyra- 

 cotherium ventkolum. 



The patella is a short, wide, thick bone, terminating in a rounded angle 

 below. Above it is truncate, with a transverse groove at the middle. 



