AESINOITHEEIUM. 49 



border of this bone runs up and becomes continuous with the inferior edge of the 

 cotylar notch, the other edge of which is continuous with the antero-inferior border 

 of the ischium, so that the notch actually opens into the upper end of the obturator 

 foramen. The angle of the ischial tuberosity (is.t.) is nearly right ; the border 

 of the bone behind the angle and the angle itself are covered by a roughened 

 epiphysial cap. The hinder border of the united ischia is slightly concave, and the 

 bones themselves are flattened near the angle and rounded near the symphysis. The 

 pubis (yu.) is a broader thin bar of bone ; it is slightly concave above and convex 

 below ; it widens out towards the symphysis {sym.). The obturator foramen {o.f.) is 

 an elongated oval, the outer end of which, as already noticed, is continuous with the 

 cotylar notch. 



The pelvis of Uintatherium differs from that just described in the following 

 points: — (1) the crista ilii is much more convex in outline; (2) the surfaces for 

 the sacral vertebrae are much more prominent and strongly marked ; (3) the symphysis 

 is less massive and the obturator foramen is wider ; (4) the ischia and pubes are 

 rather stouter and the ischial tuberosities are more developed ; (5) there is a deep 

 fossa on the visceral surface nearly opposite the acetabulum, whereas in Arsinoitherium 

 this is only slightly marked. 



In Elephas the form of the ilia is more like that described and figured, but the 

 pubes and ischia, particularly the latter, are much wider, so that the symphysis 

 is much longer and consists of distinct pubic and ischial portions united by a 

 narrow bar. One result of this is, that the ischial portion of the pelvis projects 

 much farther behind the acetabulum than in Arsinoitherium. In Elephas also 

 the sacral surfaces are better marked and the ischial tuberosities more prominent. 



The femur (text-fig. 28) is remarkable for the great antero-posterior compression 

 of the shaft and for the flatness of its posterior face, the outer border of which forms 

 a thin sharp edge. 



The head {h.) is very large and nearly hemispherical ; it looks upwards and 

 somewhat outwards, and its posterior border is crossed by a deep groove for 

 the ligamentum teres [n.l.t.). The great trochanter {g.t.) is compressed antero- 

 posteriorly, and does not rise so high as the head; its posterior face is slightly 

 concave, while anteriorly it forms a considerable rugose prominence. The lesser 

 trochanter {l.t.) is inconspicuous and close beneath the head. The shaft, as 

 already mentioned, is extremely compressed from before backwards, and its posterior 

 surface is nearly flat. The anterior face is convex towards the inner side, but 

 externally it is nearly flat and meets the posterior surface so as to form a thin 

 sharp outer border, which, near its middle point, is slightly convex, the convexity 

 being apparently the representative of the third trochanter : the inner border of 

 the shaft is rounded. The condyles {i.e., o.c), which are relatively small, are 

 subequal and are separated by a narrow but deep fossa (i.n.). Above the condyles 



H 



