AKSlNOITIlElilUiM. 
47 
Hind liimh . — The best example of the pelvis is a complete s])ecimen in the Cairo 
Museum (C. 8413), and it is upon this that the following description and figures 
(text-figs. 20, 27) are founded. 
The ilia [il.) are immensely expanded bones, of which the gluteal surface is slightly 
convex exce]h towards the superior angle, which is somewhat everted so that the 
outer surface there becomes concave. The pelvic (inner) surface is slightly concave, 
except towards the upper border, where the everted portion just referred to bears 
a deeply hollowed surface for union with the sacral vertebrae. The superior angle 
formed by the meeting of the superior border [crista ilii, c.i.) with the posterior 
is almost a right angle. In front the crista ilii sweeps round into the anterior 
border, which is greatly thickened, broadly convex, and term'nates below in the 
prominent external angle [e.a.), which, like the superior angle, is capped by a 
large rough epiphysis, that on the lower angle [e.a.) being the larger. The 
acetabular border [a.h.) is concave, and just before reichiug the acetabulum [a.) 
Text-fig. 25. 
Fifth left metacarpal of Arsinoitherium zitteli. 
cu., svu’face of contact with cuneiform ; me. 4, facet for fourth metacarpal ; unc., facet for unciform. 
I nat. size. 
it is interrupted by a roughened notch, probably for the attachment of the rectus 
femoris muscle. 
The inner border running down from the superior angle is concave except in 
its upper portion opposite the sacral facet, where it is straight; a little above the 
level of the glenoid cavity it divides into an anterior ridge continuous below with 
the anterior edge of the pubis, and a posterior ischial ridge, which runs back to 
the ischial tuberosities. The surface between these two ridges is deeply concave. 
The acetabulum [a.) is oval, its long axis corresponding with the long axis of the 
os innominatum. The pit for the ligamentum teres is very deep and extends 
upwards beyond the middle of the cavity; posteriorly the pit opens on the ischial 
surface by a deep notch in the border of the glenoid cavity. 
The anterior border of the united pubes [pu.) is slightly concave, while the posterior 
