76 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



the blade is divided into two parts by a prominent ridge, 

 the spine, which typically ends below in a more or less con- 



FiG. 20. — LeftscapulaofWolf. 

 fir/., glenoid cavity, c.cora- 

 coid. ac, acromion, sp. 

 spine. 



Fig. 21. — Left scapula of Horse. 

 This figure is much ixiore reduced 

 than Fig. 20. 



spicuous projection, the acromion, which may, however, be 

 absent, its prominence being, generally speaking, correlated 



with the presence of the 

 collar bone. A hook-like 

 process, the coracoid, rises 

 from the antero-internal 

 side of the glenoid cavity 

 and varies greatly in size 

 in the different groups of 

 mammals ; though it usu- 

 ally appears to be merely a 



Fig. 22. —Left scapula of Man in position of proCCSS of the SCapula, with 

 walking on all fours. Letters as in Fig. 20. , • i ■ • . , . . 



which it IS indistmguish- 

 ably fused, yet its development shows it to be a separate ele- 

 ment and in the lowest mammals (Prototheria), as in the rep- 



