THORACIC LIMBS. 63 



(lateral angle of human anatomy), is much heavier than the 

 others and bears a concave, pear-shaped articular facet, the 

 glenoid fossa, for articulation with the humerus. The border 

 with which this angle is more nearly continuous may be called 

 the glenoid border (<:) (axillary border of human anatomy). 



Near the narrower cranial end of the glenoid fossa is a 

 small curved projection of the bone, the coracoid process (Fig. 

 45, m}. The border upon which it lies is the coracoid border 

 (6) (superior border of human anatomy). The third border is 

 turned toward the vertebral column and is the vertebral 

 border (a). 



The angle between the glenoid and vertebral borders is the 

 glenovertebral angle (_/") (inferior angle of human anatomy), 

 and that between the coracoid and vertebral borders the 

 coracovertebral angle (e) (medial angle of human anatomy). 



The medial or costal surface (Fig. 45) is smooth and nearly 

 flat. A shallow furrow (ii) marks the position of the spine of 

 the scapula. Between the furrow and the coracoid border are 

 two oblique parallel ridges (o and #') for the insertion of muscle- 

 fibres. Near the glenoid border is a well-marked ridge sepa- 

 rating the subscapular fossa (///), comprising the greater part 

 of the medial surface of the scapula, from the fossa in which 

 the teres major muscle has origin (IV]. The surface presents 

 several nutrient foramina usually directed toward the glenoid 

 angle. 



The lateral surface (dorsal surface of human anatomy) 

 (Fig. 44) is divided by the spine (g) into two portions. The 

 portion of the scapula craniad of the spine and the cranial 

 surface of the spine bound the supraspinous fossa (fossa supra- 

 spinata) (/), while the surface caudad of the spine and the 

 caudal portion of the spine bound the infraspinous fossa (fossa 

 infraspinata) (//). 



The spine (g) begins as a triangular elevated area in the 

 middle of the vertebral margin and runs toward the glenoid 

 angle. It rises gradually for about two-fifths of its length and 

 then the margin becomes broader and the spine remains of the 

 same height to its glenoid end. There is a rough thickening, 

 the tuberosity (//) of the spine, situated on its free border about 



