ARTHROLOGY. 45 



Two anterior lateral, from anterior surfaces. 

 Two posterior lateral, from anterior surfaces. 



Movements. 



Same as preceding. 



POSTERIOR EXTREMITY. 



SACRO-ILIAC. 



An amphiarthrosis, between auricular surface of sacrum and 

 side of ilium. 



Ligaments. 



Sacroiliac, about margins of articulation. 



Superior ilio-sacral, from internal angle of ilium to sacral spine. 

 Itiferior ilio-sacral, with preceding and inserted into sides of 

 sacrum. 



Movements. 



Slight gliding. 



Sacro-iliac ligament, from sides of sacrum by its superior bor- 

 der into super-cotyloid crest and ischial border by its infeiHoi 

 border, forming, with the lesser sciatic notch, the opening by 

 which the internal obturator and pyra7?iidal muscles leave the 

 pelvis. 



An anterior border forms the greater sciatic foramen with the 

 notch, and through it pass the gluteal and sciatic vessels and 

 nerves. 



A posterior border which embraces the semi-niembranosus 

 muscle. 



ISCHIO-PUBIC SYMPHYSIS. 



In young animal is a true amphiarthrosis. 

 In adult life bones are fused together. 



COXO-FEMORAL OR HIP JOINT. 



An enarthrodia between the cotyloid cavity and the head of the 

 femur. 



Ligaments. 



Capsular, from margins of cotyloid cavity to neck of femur. 

 Transverse, converting notch into a foramen. 

 Cotyloid, deepening the cavity. 



