PELVIS. 



85 



Fig. 33* 



The internal surface is bounded above by the crest, below by a 

 prominent line the linea ilio-pectiriea, and before and behind by 

 the anterior and posterior bor- 

 ders ; it is concave and smooth 

 for the anterior two-thirds of its 

 extent, and lodges the iliacus 

 muscle. The posterior third is 

 rough, for articulation with the 

 sacrum, and is divided into two 

 parts by a deep groove ; an 

 anterior or auricular portion, 

 which is shaped like the pinna, 

 and coated by cartilage in the 

 fresh bone ; and a posterior 

 portion, which is very rough, 

 for the attachment of interos- 

 seous ligaments. 



The external surface is 

 rough, partly convex, and 

 partly concave; it is bounded 

 above by the crest; below, by 

 a prominent arch, which forms 

 the upper segment of the acetabulum; and before and behind 

 by the anterior and posterior borders. Crossing this surface in an 

 arched direction, from the anterior extremity of the crest to a notch 

 upon the lower part of the posterior border, is a groove, which 

 lodges the gluteal vessels and nerve the superior curved line ; and 

 below this, at a short distance, a rough ridge, the inferior curved 

 line. The surface included between the superior curved line and 

 the crest, gives origin to the gluteus medius muscle ; that between 

 the curved lines, to the gluteus minimus ; and the rough interval 

 between the inferior curved line and the arch of the acetabulum, to 

 one head of the rectus. The posterior sixth of this surface is rough 

 and raised, and gives origin to part of the gluteus maximus. 



The crest of the ilium is arched and sigmoid in its direction, being 

 bent inwards at its anterior termination, and outwards towards the 

 posterior. It is broad for the attachment of three planes of muscles, 

 which are connected with its external and internal borders or lips, 

 and with the intermediate space. 



The anterior border is marked by two projections, the anterior 

 superior spinous process, which is the anterior termination of the 



* The os innominatum of the right side. 1. The ilium; its external surface. 2. 

 The ischium. 3. The os pubis. 4. The crest of the ilium. 5. The superior curve'd 

 line. 6. The inferior curved line. 7. The surface for the gluteus maximus. 8. The 

 anterior superior spinous process. 9. The anterior inferior spinous process. 10. The 

 posterior superior spinous process. 11. The posterior inferior spinous process. 12. 

 The spine of the ischium. 13. The great sacro-ischiatic notch. 14. The lesser sacro- 

 ischiatic notch. 15. The tuberosity of the ischium, showing its three facets. 16. 

 The ramus of the ischium. 17. The body of the 09 pubis. 18. The ramus of the 

 pubis. 



