340 



MAMMALIA. 



bearing separate bosses or tubercles (bunodont, e.g., fig. 196); 

 somewhat later these tubercles multiply more or less irregularly 

 (as in the pigs), or they retain their original arrangement but 

 tend to become crescent-shaped (buno-selenodont, e.g., fig. 199). 

 Subsequently, as the ruminants or Pecora are gradually evolved ; 



FIG. 195. 



FORE FEET AND SECTIONS or TEETH OF ARTIODACTYLA. 



A. Left fore foot of Hycemoschus, two-thirds nat. size. B. Left fore foot of 

 Gelocus, one-half nat. size. c. Eight fore foot of Capreolus, one-third 

 nat. size. D. Eight fore foot of Bos, about one-quarter nat. size. 

 E. Transverse section of molar of Gelocus, nat. size. F. Transverse 

 section of molar of Bos, about one-third nat. size. 



v c, cement; en., cuneiform; d, dentine; e, enamel; lu., lunar; m, magnum; 

 p, pulp-cavity; sc., scaphoid; td., trapezoid; un., unciform ; n v, num- 

 bers of digits. 



the crescent-shaped tubercles are emphasized and deepened 

 (i.e., become truly selenodont) ; while eventually the antelopes 

 and cattle exhibit teeth (fig. 195 F) with selenodont crowns 

 almost or quite as deep (hypsodont) as those of the horses 

 among Perissodactyla. It is very probable that the early 



