ARSINOrniEKIUM. 
47 
Uind Limh. — The best example of the pelvis is a complete specimen in the Cairo 
iNIuseum (C. 8413), and it is npon this that the following description and figures 
(text-figs. 27) are founded. 
The ilia [il.) are immensely expanded hones, of which the gluteal surface is slightly 
convex except 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 tlie posterior 
is almost a right angle. In front the crista ilii sweeps round into the anterior 
border, which is greatly thickened, broadly convex, and terminates below in tlie 
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.b.) is concave, and just before reaching the acetabulum [a.) 
Text-fig. 25. 
Fifth left metacarpal of Arsi)ioitheriuni zitteli. 
cu., surface of contact with cuneiform ; me. 4, facet for fourth metacarpal ; unc., facet for unciform. 
2 nat. size. 
it is interrupted by a roughened notch, probably for the attachment of the rectas 
femoris muscle. 
The inner border running down from the superior angle is conca m except in 
its upper portion opposite the sacral facet, where it is stiaight; a little ab ve 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, v hich 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 innoniinaticm. The pit for the ligamentwn teres is very deep and extejids 
upwards beyond the middle of the cavity; poslericrly the pit opens on the ischial 
surface by a deep notch in the border of the glencid cavity. 
The anterior border of the united pubes [p'U.) is slightly concave, while the posterior 
