PELVIC LIMBS. 77 
piece, as made up of ilium (Fig. 55, 7), ischium (//), and 
pubis (///). 
The ilium (/) is somewhat contracted at the middle and 
broader at its ends. One end enters into the acetabulum 
(Fig. 55, @) and forms about 
one-fifth the articular surface. 
This end is also the thickest part 
of the bone. The lateral surface 
of the ilium is concave for the 
attachment of muscles. The me- 
dial surface is smooth over its 
acetabular half and rough over its 
sacral half. The rough portion is 
marked at its junction with the 
smooth portion by the ear-shaped 
auricular impression by which 
the bone articulates directly with 
the sacrum. The caudal half of 
that part of the medial surface 
craniad of the auricular impression 
gives attachment to the ilio-sacral \hN 
ligaments which bind the ilium to Nh 
the sacrum. The dorsal border ssculll 
is straight at its cranial end and yy, 55. —InNominaTE BONE OF 
concave and rounded at its caudal - aoe Cat, VENTROLATERAL 
end. Between the two portions /, ilium; Z/, ischium; /7/, pubis. 
and at the dorsal edge of the @, crest of the ilium; 4, posterior in- 
ff . ferior spine; ¢, great sciatic notch; d, 
auricular surface is a protuberance acetabulum; a’, incisura acetabuli: ¢, 
; ‘ spine of the ischium; /, lesser sciatic 
weenie onding oo the Posterior rakes g tuberosity & the ischium; 
inferior spine (Fig. 55, 4) of the 2, ramus of the ischium; 2, ramus of 
1s Y the pubis; 7, obturator foramen; &, 
human ilium. The concavity of pubic tubercle; ¢. iliopectineal line: 
the dorsal border (c) corresponds t", ilio-pectineal eminence; #2, anterior 
to the great sciatic notch of the *“P°mOr Process. 
human ilium. At its caudal end is the short spine of the 
ischium (c), which is nota part oftheilium. The ventral border 
of the ilium is broad caudad, becoming narrower craniad. The 
lateral margin of the ventral border is continued to a tuberosity 
at the edge of the acetabulum; its medial margin is called the 
SS 
