_O.il._, Ilium; _O.p._, pubis; _O.is._, ischium; _A.o.i._, wing of
ilium; _C.o.i._, shaft of ilium; _Cr.o.i._, anterior border (crest)
of ilium; _1_, obturator foramen; _2_, acetabulum; _3_, internal
angle of ilium; _4_, external angle of ilium; _5_, gluteal line;
_6_, psoas tubercle; _7_, _8_, acetabular and symphyseal branches of
pubis; _9_, _10_, acetabular and symphyseal branches of ischium;
_12_, lesser sciatic notch; _13_, ischial arch; _14_, great sciatic
notch; _15_, symphysis pelvis; _17_, ilio-pectineal eminence; _18_,
anterior borders of pubic bones; _19_, posterior gluteal line.
(Struska, Anat. d. Haustiere.)
]
The =pelvic surface= (Facies pelvina) faces in the opposite direction;
it is convex, and consists of two distinct parts. The inner triangular
part (Pars articularis) is roughened for ligamentous attachment, and
bears an irregular facet, the =auricular surface= (Facies auricularis),
for articulation with the sacrum. The outer quadrilateral part (Pars
iliaca) is in general smooth. It is crossed by the =ilio-pectineal line=
(Crista iliopectinea), which begins below the auricular surface and is
continued on the shaft of the bone to join the anterior border of the
pubis. The line is interrupted by furrows for the iliaco-femoral
vessels, and below these it bears the =psoas tubercle= (Tuberculum
psoadicum), which gives attachment to the psoas minor muscle. The
iliacus muscle is attached to the surface external to the ilio-pectineal
line.
The =anterior border= or =crest= (Crista iliaca) is concave, thick, and
rough.
The =internal border= is deeply concave; its middle part forms the lower
boundary of the =great sciatic foramen=, and it is continuous behind
with the =superior ischiatic spine=.
The =external border= is concave and in great part rough. Its fore part
is crossed by grooves for the ilio-lumbar vessels, which are continued
on the pelvic surface. The =nutrient foramen= is usually situated on or
near the posterior part of this border.
[Illustration: