512 



ZOOLOGY 



SECT. 



ex.cc 



FIG. 1151. Skull of Ant-eater (Myrme- 

 cophaga), ventral view. Letters as in 

 Fig. 1150. In addition, b.oc. basi- 

 occipital ; glen, glenoid surface for 

 mandible ; pter. pterygoid. 



short and powerful, with well- 



Ur 



is broad and rounded ; the anterior 

 border unites with the coracoid 

 process so as to convert the 

 coraco-scapular notch into a fora- 

 men. In the middle of the spine 

 there is a triangular process : a 

 ridge on the post-spinous fossa pre- 

 sents the appearance of a second 

 spine. The fibres of origin of the 

 sub-scapularis muscle extend on to 

 the outer surface as far forward as 

 this ridge, so that the part of the 

 outer surface behind the ridge 

 corresponds to a part of the sub- 

 scapular fossa, which in other 

 Theria is co-extensive with the 

 i nner surface . Except in Cydoturus 

 the clavicles are rudimentary. All 

 the carpal bones are distinct. 



In the Armadillos the scapula 

 (Fig. 1153) has an extremely 

 prolonged acromion (acr.), some- 

 times articulating with the humerus. 

 A ridge (sp f .) representing a second 

 spine is present. The clavicle is 

 well developed. The humerus is 

 developed processes and ridges, and 



s.oc 



FIG. 1152.---Skull of Three-toed Sloth (Bradypus tridactylus). Letters as in Fig. 1150. 



with a foramen above the inner condyle (entepicondylar foramen). 

 The carpus consists of the ordinary eight bones. 



