128 



COPE 



dimensions ; distal end of astragalus not 



forming a ginglymus ; Perissodadyla. 



Feet with the digits 3 and 4 predominating 

 and subequal ; astragalus with a distal 

 ginglymus ; Ariiodactyla. 



The Peeissodactyla exhibit various series of forms in 

 which the toes diminish in number, from four in front and 



Fig. 63. — Aphelops meyalodus Cope, one-sixtb natural size; B, inferior 

 view of cranium, Original. Hornless rhinoceros from the Loup Fork Neo- 

 cene, Colorado. 



