64 



ELEMENTS OF MAMMALIAN ANATOMY 



The outer surface of this bone is divided by a strong spine into 

 two nearly equal fossa?, the cranial of which is the supraspinous, 

 and the caudal one the infraspinous, fossa. From the lower 

 part of the spine project the acromion and mclacromion proc- 



/-A 



^-r/^ 



Fig. 31. — Lateral or Outer Aspect of the Scapula. 

 ac. Acromion process; ax, axillary border; c, coracoid process; gl, glenoid cavity; 

 m, metacromion process; sc, scapular notch; sp, spine; sup. fos, supraspinous 

 fossa; vr, vertebral border; n, neck. 



esses. The subscapular fossa occupies the entire inner or 



medial surface. 



A slight constriction between the base of the spine and the 



margin of the glenoid cavity 

 is termed the neck. From the 

 cranial side of the latter the 

 coracoid process curves mediad. 

 The clavicle is a slender 

 curved bone, about one inch 

 long, imbedded in the muscle 



between the manubrium and the coracoid process (Fig. 22). 



It does not articulate with any bone, but is held in place 



by the cephalohumeral and cleidomastoid muscles (Fig. 49). 

 The shoulder girdle varies somewhat among the Mammalia. 



The clavicle is never fully developed in any of the Carnivora. 



Primates, Chiroptera, Edentata, and Monotremata are the 



Fig. 32. — Caudal Aspect of Left 



Clavicle. 



b. Medial end; a, lateral end. 



