106 THE SKELETON OF THE HORSE 
on the shaft of the bone to join the anterior border of the pubis. The line is inter- 
rupted by furrows for the iliaco-femoral vessels, and below these it bears the psoas 
tubercle (Tuberculum psoadicum), which gives attachment to the psoas minor mus- 
cle. The iliacus 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 
Greater sciatic 
notch 
Ischiatic spine 
Nutrient foramen Tuber 
es Dern ane COL@ 
Tuber Lesser sciatic Psoas tubercle 
ischit notch 
Acetabular branch of pubis 
Ventral ischiatic Symphyseal branch 
spine of pubis 
Fic. 85.—Ricut Os Cox.® anp Sacrum oF Horse; Ricur Larerau 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] rectus femoris; 5, crest to which 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 coxa, forms the basis of the point of the hip. It isa 
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 
