454 



University of California Piiblications in Zoology [Vol. 13 



scapula. In the squirrels and rat it is complete, that is, it forms 

 a bony link between these two points. 



The scapula (figs. C, D) may be described roughly as a triangu- 

 lar plate of bone with a high ridge, the spinous process, on its 

 lateral surface. The flat, triangular plate is longest in the dorso- 

 ventral direction, and its thickened ventral angle may be called the 

 head of the bone. The distal surface of the head forms the concave 

 glenoid fossa, in which the head of the humerus articulates. The 

 coracoid process arises at the cephalic border of the glenoid fossa, 

 and curves mesiad and ventrad. Its tip is in close relation with 

 the lesser tuberosity of the humerus. The cephalic border of the 



glvt. ang.- 



_ _ vert. bd. 



- crvt. ang. 



vert. bd. 



glen. ang. 



sp.. 



■cor. bd. 



D 



nk. 



cor. proc. 

 ^~ - supgl. tub. 



lat. ext. 



mes. ext. 



Fig. 



Fig. 



Fig. 



acr.- 



cor. 



cor. 



crvt. 



glen 



glen 



glvt. 



infs. 



C. Lateral view of right scapula of the gopher, X 2t 



D. Anterior view of right scapula of the gopher, X 21 



E. Ventral view of right clavicle of the gopher, X 2§ 



-acromion 



T)d. — coracoid border 

 proc. — coracoid process 

 ang. — coracovertebral angle 

 ang. — glenoid angle 

 bd. — glenoid border 

 ang. — glenovertebral angle 

 fas. — infraspinous fossa 



lat. ext. — lateral extremity 



mes. ext. — mesial extremity 



nk. — neck 



sp. — spine 



siipgl. tub. — supraglenoid tubercle 



sups. fos. — supraspinous fossa 



vert. bd. — vertebral border 



