ILIUM. 85 



sacrum, and gives attachment to the inferior sacro-iliac ligament. 

 The iliacus muscle is attached to the venter surface. On the 

 lower portion is a line or ridge continuous with the anterior edge 

 or brim of the pubis ; together these form the ilio-pectineal line, 

 which inferiorly separates the true pelvis from the false. On the 

 inferior border of the shaft is the nutrient foramen, and in front 

 of the acetabulum a second depression for the inner head of the 

 rectus feraoris muscle. Below this depression is the ilio-pectineal 

 eminence, which marks the junction of the ilium and the pubis, 

 and gives attachment to the psoas parvus muscle. The inner 

 part is smooth, concave, and grooved backwards and downwards 

 for the obturator vessels 



Fia. 20. 



Left poatero-lateral view of a Horse's pelvis. 1, Anterior iliac spine ; 2, 

 Posterior iliac spine. The iliac crest is the border joining 1 and 2 ; 3, niac 

 shaft ; 4, The acetabulum, the large rough ridge above is the sciatic spine ; 

 6, Inferior ischiatic spine, posterior to which is the tuberosity. 



The anterior border, or crest of the ilium, lies above the sacral 

 transverse process. It is concave above, convex below, thin in 

 its middle, and roughened for the attachment of the longissimus 

 dorsi and other muscles. Internally it terminates in a rounded 

 eminence, the posterior iliac spine, which rises above the last 

 lumbar and first sacral spines, and forms the highest part of the 

 croup. Externally and anteriorly it terminates in the anterior 

 iliac spine, which consists of four eminenges, two superior and 

 two inferior, supported on a thick, strong, projecting bony plate ; 

 these eminences give attachment to the oblique and transverse 



