150 



OSTEOLOGY. 



anterior and posterior borders. It presents anteriorly a large smooth concave 

 surface called the internal iliac fossa or venter of the ilium ; it lodges the Iliacus 

 muscle, and presents at its lower part the orifice of a nutritious canal. Behind 

 the iliac fossa is a rough surface, divided into two portions, a superior and an 



Fig. 97. Right Os Innominatum. External Surface. 



Anlrrior 



'uftruir 

 Sfii* 



fl*o-pictlnta 2 Lint 

 tiimbir nut'i LICT. 



Spine of Piiltt* 

 far Pou fart's LIGAMENT 



AtujlitfPuJita 



ABDOMIMI* 

 MIOALIS 



inferior. The inferior or auricular portion, so called from its resemblance to the 

 external ear, is coated with cartilage in the recent state, and articulates with a 

 similar shaped surface on the side of the sacrum. The superior portion is con- 

 cave and rough for the attachment of the posterior sacro-iliac ligaments. 



The crest of the ilium is convex in its general outline and sinuously curved, 

 being bent inwards anteriorly, outwards posteriorly. It is longer in the female 

 than in the male, very thick behind, and thinner at the centre than at the 

 extremities. It terminates at either end in a promindnt eminence, the anterior 

 superior, and posterior superior spinous process. The surface of the crest is 



