

230 



THE SHOULDER GIRDLE. 



[CHAP. 



both of these it is very short, and is suspended by long 

 ligaments between the scapula and the sternum. (See Fig. 

 75.) In many species, as in the Porcupines, in which the 

 clavicular arch is more complete, the true clavicle is con- 

 nected with the presternum by a long cartilaginous omo- 

 sternum. In others, as the Beaver, this is replaced by a" 

 ligamentous band. Rudiments of the sternal end of the 

 coracoid are often present, sometimes cartilaginous, some- 

 times ossified. 



Fig. 75.— Shoulder girdl**, with uppei end of sternum (inner surface), of a young 

 Rabbit {Lcpus cuniculus), after Parker, §. fis presternum ; sr first sternal rib 

 ost omosternal cartilage ; pc precoracoid cartilage ; cl ossified clavicle ; mss carti- 

 laginous mesoscapular segment ; c coracoid ; a acromion ; ma metacromion ; aj 

 anterior fossa ; /£/* posterior fossa. 



In the Carnivora the anterior and posterior fossae of 

 the scapula are nearly equal in area. (See Fig. 72, p. 223.) 

 The spine and acromion are fairly developed, the latter 

 often with a broad metacromial process. The coracoid is 

 much reduced. According to Parker a portion of the 

 scapula, near the coracoid border, ossifies from an indepen- 

 dent centre. The clavicle is sometimes absent, and when 

 present varies much in its development, but is always 

 rudimentary and suspended in the muscles, never reaching 



