~2 ELEMENTS OF MAMMALIAN ANATOMY. 



pus, the descendant of Hyracotherium, also shows a dis- 

 tinct radius and ulna, but in the later forms of the horse 

 line the ulna gradually diminishes in size and becomes 



me 



F { 



z 



24 



FIG. 35. (See opposite page for explanation.} 



more and more coalesced with the radius, until in Equus 

 scarcely more than the proximal third remains (Fig. 37). 

 Carpus.- -The carpus consists of seven bones arranged 



