162 



THE PELVIS AND THE GENITAL ORGANS. 



one. At their point of junction is the cavity of the 

 acetabulum for articulation with the head of the femur 

 or thigh bone. 



The upper, expanded portion of the os innominatum 

 is the ilium, whose upper border is known as the crest 

 and which has two spinous processes front and back, a 

 superior and an inferior, the superior spine being in each 



Crest of ilium. 



Anterior gluteal line. 



Ala of ilium. ^ .J^^jjjj jj|!j |i ?,y &? "- Anterior superior spine. 



ill 



Iliac portion. 



Semilunar 



surface. 



Acetabular fossa 



Cotyloid notch. - 

 Ischiatic portion. 



Tuberosity of ischium. 



-" Iliopectineal eminence. 



Pubic portion. 



-Spine of pubes. 



\ 



Ramus of pubes. 



Obturator foramen. Ramus of ischium. 



FIG. 63. The right innominate bone. (After Toldt.) 



case the larger. These spines, especially the anterior 

 superior spines, and the crest give attachment to many 

 muscles, and to the outer surface of the bone the glu- 

 teal muscles are attached. The anterior superior spine 

 is also important in making measurements to ascer- 

 tain whether both legs are of equal length. 



Below the ilium posteriorly is the body of the isch- 



