THE SKELETON. 



8l 



(96 



^V-^- trch. 

 *inlch.r. 



l.trch - 





n.a 5.-U* 



osity. The acetabulum or cotyloid cavity forms the cup 

 for the articulation of the femur. The interruption in its 

 ventral border is the cotyloid 

 notch, at whose base there is 

 a depression for the attach- 

 ment of the ligamentum teres 

 holding the femur in place. 

 The junction of the pubis with 

 its fellow is known as the sym- 

 physis. The cephalic portion 

 of the bone lying on either side 

 of this is called the body, the 

 caudal part taking the name 

 of ramus. The latter forms 

 part of the boundary of the 

 obturator foramen and meets 

 the ramus of the ischium. This 

 foramen gives passage to the 

 obturator nerve and vessels. 



In the Sirenia, which have 

 no pelvic limbs, the innomi- 

 nate bones are rudimentary. 

 In the Cetacea these bones are 

 also rudimentary, which fact 

 indicates that the ancestors of 

 these forms possessed func- 

 tional hind -limbs. 



The femur, or thigh-bone, 

 may be recognized by its 

 spherical head with a pit for 

 the attachment of the liga- 

 mentum teres wliich aids in holding the head in the ace- 

 tabulum. 



The greater trochanter projects from the proximal end of 



7 



FIG. 40. CAUDAL ASPECT OF 

 FEMUR. 



ex tub, External tuberosity; int 

 tub, internal tuberosity; ex 

 end, external condyle; int end, 

 internal condyle; i end t, in- 

 tercondylar notch or fossa ; 

 intch r, intertro chanter ic 

 ridge ; g trch, greater trochan- 

 ter; hd, head; lin as, linea as- 

 pera; / trch, lesser trochanter; 

 nk, neck; pit, pit for the liga- 

 mentum teres ; tr fos, trochan- 

 teric fossa or digital fossa. 



