294 SKELETON OF THE BABBIT 



bones of the limbs are mostly elongated, and provided with 

 epiphyses at their ends. 



A. The Pectoral Girdle. 



This Ues outside the ribs, and is attached to the axial 

 skeleton by muscles and ligaments only. In the rabbit, as 

 in nearly all other mammals, it is very incomplete : the dorsal 

 or scapular portion on each side is well developed, but the 

 ventral or coracoid portion is almost entirely absent, being 

 represented merely by a small knob of bone fused with the 

 scapula : the clavicles also are imperfect. 



i. The scapula is a triangular plate of bone, the 

 apex of which is directed downwards and for- 

 wards, and is expanded and hollowed on its 

 ventral surface to form the shallow glenoid 

 cavity, with which the head of the humerus 

 articulates. 



Of the three borders, the anterior or 

 coracoid border is nearly straight ; the pos- 

 terior or glenoid is sHghtly concave ; and the 

 dorsal or suprascapular, which is the shortest 

 of the three, is convex and supports the car- 

 tilaginous suprascapula. 



The spine is a prominent ridge running 

 along the outer surface of the scapula, nearly 

 parallel to and a short distance behind the 

 coracoid border. It is continued ventrally 

 into a free, downwardly directed process, the 

 acromion, from the posterior border of which 

 the long metacromion projects backwards. 



The coracoid border is continuous below 

 with the coracoid process, which overhangs 

 the glenoid cavity, and is produced inwards 

 into a blunt hook. This is the sole represen- 

 tative of the coracoid portion of the pectoral 

 girdle, and is a distinct bone in the young 

 rabbit. 



