260 



THE SP10ULDER GIRDLE. 



[CHAP. 



acromion is a long strip of cartilage connecting the spine 

 with the end of the coracoid, while the coracoid border of 

 the scapula and the coracoid bone join each other in front 

 converting the coraco-scapular notch into a small oval fora- 

 men (csf\ The acromion and coracoid remain united in the 

 Two- toed Sloth \Choloepus) and the extinct Megatherium; 

 but in Bradypus the acromion gradually becomes reduced in 



FIG. 82. Right scapula of Great Armadillo (Priodon gigas), \. pf postscapular 

 fossa ; rt/prescapular fossa ; gc glenoid cavity ; csn coraco-scapular notch ; c cora- 

 coid ; a. acromion ; h articular surface for humerus. 



size, losing its connection with the coracoid, and finally 

 remains a mere styliform, or slightly flattened process. 



The coracoid in both forms is unusually large, ossifies 

 ectosteally according to Parker, and has an epiphysis on its 

 free hook-like extremity. 



The clavicle (d) of Cholcepus is well developed, attached 

 external to the loop of bone on the scapula, formed by the 



