118 TEETIAET VEETEBEATA OF THE EATtTM. 



foramen, but there is a deep fossa lying between the condyle and the olecranon fossa {o.f,), 

 which also is very deep. The outer condyle is comparatively small ; from it the edge 

 of the bone is continued up as a narrow backwardly directed flange, which dies away 

 just below the middle of the shaft; distally this ridge forms the outer border of the 

 olecranon fossa, and higher up the sharp outer border of the expanded distal end of 

 the bone, which above the olecranon fossa is strongly concave from side to side. The 

 edge also is in part the equivalent of the supinator ridge, and the large development 

 of this and of the inner condyle indicates that the limb was capable of extensive 

 movements of pronation and supination not found in the more specialised Ungulates. 

 The distal articulation is divided into an outer and an inner lobe by a shallow 

 depression; above the outer trochlea the front of the bone is occupied by a well- 

 marked coronoid fossa {c.f.). 



The proximal end only of the ulna is known (PI. XI. fig. 7). The olecranon process 

 {ol.) is large, thickened at the extremity, and rises high above the articulation ; it is not 

 directed backwards to any great extent, but merely continues upwards the long axis 

 of the shaft. The sigmoid notch is deeply concave, the upper part of the articulation 

 being considerably prolonged forwards. The lower portion of the humeral surface is 

 deeply bilobate ; the radius seems to have been in contact with the outer lobe only. 

 Beneath the articulation on the anterior face of the bone towards the outer side there 

 is a deep depression {r.) for the radius. 



Hind Limb. — The pelvis (PL XI. figs. 9, 9 a ; text-fig. 68, D) diff"ers widely from 

 that of the later Proboscidea, owing mainly to the narrowness of the ilium. The 

 crista ilii (c.i.) is short and almost at right angles to the sacral and acetabular 

 borders, which are parallel with one another. The outer angle of the crista forms a 

 blunt projection. The sacral surface is very long, extending over the anterior three- 

 fourths of the sacral border ; it is gently convex from above downwards, and from its 

 position and antero-ppsterior extent it shows that the long axis of the ilium is nearly 

 parallel with that of the vertebral column. The acetabular border is gently concave 

 in its anterior two-thirds ; posteriorly it seems to divide on either side a strongly 

 marked pit (Ifor the rectus femoris muscle) lying immediately above and in front 

 of the rim of the acetabulum. The gluteal surface is slightly concave from 

 side to side ; the pelvic (inner) surface is nearly flat. On the ventro-internal face 

 of the ilium is a prominence (ileo-pectineal), from which there runs back a ridge 

 continuous with the anterior border of the pubis {pn.). The acetabulum {a.) is 

 horseshoe-shaped, the very prominent raised rim being interrupted postero-inferiorly 

 by a wide notch, which leads into the large pit for the ligament, and opens 

 externally on the surface of the ischium. The puUs {pu.) is for the most part broken 

 away in all the specimens examined : this seems to be the consequence of the 

 slenderness of the free portion of this bone. The ischium [is.) is much stouter and 



