SCAPULA. 67 



extent, but its inferior angle is situated about the level of the 

 first rib, the posterior angle being usually at or near the level of 

 the sixth or seventh. It offers for consideration two surfaces, 

 three boi'ders, and three angles. 



The external surface or dorsum of the scapula is divided into 

 two unequal ]3arts by a crest running nearly the whole length 

 of the bone, termed the spine, which at its broadest part has a 

 roughened tubercle to which the trapezius muscle is attached; 

 the clavicle, in animals which possess one, is attached to the 

 inferior extremity of the spine. The hollow part in front of the 

 spine, the antea spinatus fossa, receives the antea spinatus 

 muscle, and the postecc spinatus fossa, the larger of the two, is 

 occupied by the postea spinatus muscle ; the nutrient foramen is 

 in this fossa. 



The internal or venter surface is smooth, though uneven ; its 

 fossa, the fossa subscapularis, lodges the subscapularis muscle, and 

 the rough triangular spaces at the upper angles give attachment 

 to the serratus magnus and rhomboidei muscles. 



The superior border is nearly straight, roughened, and has the 

 "broad cartilage of prolongation fixed to it. The anterior border 

 is superiorly convex and sharp, and inferiorly concave and 

 blunted, and it terminates in a large, rough, hemispherical, and 

 internally a somewhat bent process, the coracoid apophysis, to 

 which the coiaco-humeralis and coraco-radialis muscles are 

 attached. This process is formed from a separate point of 

 ossification. The posterior border is blunt and rough, and affords 

 attachment to several muscles. 



The anterior or cerviccd angle is thin, while the ^posterior or 

 dorsal angle is thick and tuberous. The inferior or humeral 

 angle is expanded, and separated from the rest of the bone by a 

 constriction or neck ; this extremity is the strongest part of the 

 bone, and contains a shallow, oval, articular depression, the glenoid 

 cavity, articulating with the humerus, and surmounted by a rim 

 of bone to which the capsular ligament is attached ; at its inner 

 side there is a notch for the passage of blood-vessels. 



