PELVIC LIMBS. 



77 



piece, as made up of ilium (Fig. 55, /), ischium (//), and 

 pubis (///). 



The ilium (/) is somewhat contracted at the middle and 

 broader at its ends. One end enters into the acetabulum 



(^''^- 55' <'0 '^'^^-^ 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 

 ligaments which bind the ilium to 

 the sacrum. The dorsal border 

 is straight at its cranial end and fig. 55. — Innominaik. J5one of 



concave and rounded at its caudal ^""^^t *^^'' Ventrolateral 



View. 

 end. Between the two portions y_ i,i^,„. j^^ j,,,,;^,^,. j^j^ p^^is. 



and at the dorsal edge of the '^. crest of the ilium; d, posterior in- 

 . f. . , ferior spine; c, great sciatic notch; (f, 



auricular surface is a protuberance acetabuhun; </', incisma acetabuli; e, 

 corresponding to the posterior -^'i'^e "f ''^^ ischium; /, lesser sciatic 

 . . , notch; g, tuberosity of the ischium; 



inferior spine (Fig. 55, /;) of the //, ramus of the ischium; i, ramus of 



human ilium. The concavity of ^'^^P^'t^ >- obturator foramen; k, 



■' pubic tubercle; /, ihopectmeai hne; 



the dorsal border (r) corresponds /', ilio-pectineal eminence; w, anterior 



to the great sciatic notch of the '"?"""'' P^°'"''- 

 human ilium. At its caudal end is the short spine of the 

 ischium (r), which is not a part of the ilium. 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 



