ARTICULATIONS. 



also (lig. ilio-lumbale inferius) to the inner rough surface of the 

 ilium between its crest and articular surface. Great (posterior) 

 sacro-sciatic : This is a triangular layer attached by its base to 

 the posterior inferior iliac spine, back of the transverse tu- 

 bercles and lateral margins of the third to fifth sacral segments, 

 and side of the first coccygeal segment; its apex, expanding 

 somewhat, is attached to the inner side of the ischial tuber- 

 osity just below the groove for the Obturator internus tendon. 

 A prolongation (processus falciformis) of its inner border runs 

 upward and forward on the inner side of the ischial ramus. 

 Small (anterior) sacro-sciatic. This is a triangular layer in front 

 of the preceding, attached by its base to the lower two sacral 

 segments and first coccygeal segment, and by its apex to the 

 tip and upper aspect of the ischial spine. [291] 



Symphysis Pubis. There is an amphiarthrosis between 

 the bodies of the pubic bones. Between the hyaline carti- 

 lage plates covering them is seen an interposed fibro-cflxtilage 

 in whose interior is a vertical cleft; this has no synovial 

 membrane. The ligaments are anterior pubic, transverse and 

 (superficially) oblique fibres connecting the bones; posterior 

 pubic, weak transverse fibres connecting the bones behind; 

 superior pubic, weak transverse fibres connecting the pubic 

 crests; and inferior or subpubic, a strong band connecting the 

 bones below, in the pubic arch, and extending laterally to the 

 descending rami, while its lower border is free. [292] 



Triangular Ligament of Perineum. This is a membranous 

 layer which fills the pubic arch below, and is distinct from the 

 subpubic ligament. Laterally it is attached to the sides of the 

 arch; its base fuses with Colics' fascia; its apex (transverse 

 perineal ligament) is free and well-defined. It has two surfaces, 

 perineal and pelvic. [292] 



Obturator Membrane. This is a membrane which fills the 

 thyroid foramen and is attached to the pelvic aspect of the 

 circumference. At its highest point it is incomplete and forms 

 a U-shaped border, for the obturator canal. [293] 



[189] 



