THE COXAL BONE 



171 



an auricular surface, covered with cartilage in the recent state, for articulation 

 with the lateral aspect of the upper portion of the sacrum; above the auricular 

 surface are some depressions for the posterior sacro-iliac ligaments and a rough 

 area reaching as high as the crest, from which parts of the sacro-spinalis {erector 

 spinoe) and multifidus take origin. The rough surface above the auricular facet is 

 known as the tuberosity of the ilium. 



The ischium [os ischii] consists of a bod}^, a tuberosity, and a ramus. The 

 body, which has somewhat the form of a triangular pyramid, enters superiorly into 



Fig. 206. — The Left Coxal or Hip-bone. (Medial aspect.) 



Quadratus lumborum 



Sacro-spinalis 



Tuberosity 



Multifidus 



Transversus muscle and 

 iliac fasica 



Ant. sup. spin6 

 of ilium 



Ant. inf. spine of ilium 



Psoas parvus 



Ilio-pectineal 

 eminence 



Groove for pudic 

 vessels and 

 nerves 

 Sacro-tuber- 

 ous ligament 



Tuberosity of 

 ischium 



Transversus 

 perinei 



Groove for obturator 

 nerve and vessels 



Symphysial surface 

 Levator ani 



Junction of pubis Crus penis and Sphincter Arcuate 

 and ischium Ischio- urethrae ligament 



cavernosus membranaceae 



the formation of the acetabulum, to which it contributes a little more than two- 

 fifths, and forms the chief part of the non-articular portion or floor. The inner 

 surface forms part of the minor (true) pelvis and gives origin to the obturator in- 

 ternus. It is continuous with the ilium a little below the terminal (iho-pectineal) 

 line, and with the pubis in front, the line of junction with the latter being fre- 

 quently indicated in the adult bone by a rough line extending from the ilio-pec- 

 tineal eminence to the margin of the obturator foramen. The outer surface in 

 eludes the portion of the acetabulum formed by the ischium. The posterior sur- 

 face is broad and bounded laterally by the margin of the acetabulum and behind 



