108 



THE SKELETON OF THE HOHSE 



The posterior border is thick and rough. It slopes medially and forward 

 to meet the border of the other side, forming with it the ischial arch (Arcus 

 ischiadicus) . 



The medial border meets the opposite bone at the symphysis isehii. 



The lateral border is thick and rounded, but concave in its length; it forms 

 the lesser sciatic notch (Incisura ischiadica minor), the lower boundary of the lesser 

 sciatic foramen. 



The antero-medial angle or symphyseal branch (Ramus symphyseos) 



Crest of ilium 



Grooves for 

 iliaco-femoral 



vessels 



Depression for 



medial tendon 



of rectus 



femoris 



Obturator furoi/wn 



Fig. 87. — Ossa Coxarum of Mare; \'extral A'iew. 

 A, Wing, A', shaft of ilium; B, acetabular brancii, B\ symphyseal branch, of pubis; C, body, C, acetabular 

 branch (shaft), C". sj-mphyseal branch, of ischium; 1, auricular surface; 2, ilio-pcctineal line; 2\ psoas tubercle; 3, 

 arcuate line; 4, articular part, .5, iliac part, of pehuc surface of ilium; 6, ilio-peetineal eminence; 7, pubic tubercle; 8 

 acetabular fossa; 9, articular surface of acetabulum (facies lunata) ; 10, symphysis pelvis; 11, pubic groove. Dotted 

 lines indicate primitive division of os coxae. 



meets the pubis, with which it forms the medial boundary of the obturator 

 foramen. 



The antero-lateral angle or acetabular branch (Ramus acetabularis) joins the 

 other two bones at the acetabulum, of which it forms more than half. Dorsally 

 it bears part of the ischiatic spine (Spina ischiadica), and medially it is grooved for 

 the obturator vessels. The term shaft is often applied to the constricted part of 

 the acetabular branch. 



The postero-medial angle joins its fellow at the symphysis. 



The postero-lateral angle is a thick, three-sided mass, the tuber isehii (Tuber 

 ischiadicum) ; its lower border is the ventral ischiatic spine, to which the biceps 

 femoris and semitendinosus muscles are attached. 



