106 



THE SKELETON OF THE HOESE 



on the shaft of the bone to join the anterior border of the pubis. The hne is inter- 

 rupted by furrows for the ihaco-femoral vessels, and below these it bears the psoas 

 tubercle (Tuberculum psoadicum), which gives attachment to the psoas minor mus- 

 cle. The ihacus muscle is attached to the surface lateral to the ilio-pectineal line. 



The anterior border or crest (Crista iliaca) is concave, thick, and rough. 



The medial border (Margo medialis) is deeply concave. Its middle part forms 

 the greater sciatic notch (Incisura ischiadica major) and it is continuous behind 

 with the ischiatic spine. 



The lateral border (Margo lateralis) is concave and in great part rough. Its 

 anterior part is crossed by grooves for the ilio-lumbar vessels, which are continued 



Sacral spines 



Tuber sacrale Crest of ilium 



Apex of sacrum 



Tuber 

 coxae 



Acetabular branch of pubis 



Ventral ischiatic 

 spine 



Symphyseal branch 

 of pubis 



Fig. So. — Right Os Cox-e and Sacrum of Horse; Right Lateral View. 

 1, Gluteal line; 2, impression of ilio-lumbar artery; 3, impression of iliaco-femoral artery; 4, depressions for at- 

 tachments of tendons of origin of J rectus femoris; 5, crest to whicii lateral tendon of rectus femoris and capsularis are 

 attached; 6, 6', articular surface of acetabulum (facies lunata) ; 7, acetabular fossa; 8, obturator foramen; 9, line for 

 attachment of gemellus muscle; 10, lateral border of sacrum; 11, dorsal sacral foramina. 



on the pelvic surface. The nutrient foramen is usually situated on or near the 

 posterior part of this border. 



The medial angle is termed the tuber sacrale; it curves upward and a little 

 backward opposite to the first sacral spine, and forms here the highest point of the 

 skeleton. It is somewhat thickened and rough. 



The lateral angle, tuber coxae, forms the basis of the point of the hip. It is a 

 large quadrangular mass, narrow in its middle, and enlarged at either end, where 

 it bears a pair of tuberosities. It is roughened for muscular attachment. 



The acetabular angle (Angulus acetabularis) meets the other two bones at the 

 acetabulum, of which it forms about two-fifths. Its prominent dorsal border forms 



