192 THE MAMMALIA. 



the sharp ridges of the crowns of their teeth. 

 Although the fore-foot of the tapir possesses four 

 perfect toes, still, from an examination of the 

 skeleton of the foot, it becomes evident at once that 

 the second toe from the inner side, corresponding 

 with the middle toe of the five-toed limb, is more 

 strongly developed than the rest, and that it stands 

 in that peculiar position which we have shown to 



1 i 



FIG. 32. Back Molar of the Lophiodon parisiensis, on the left 



from below. 

 A, a, Front and back outer tubercle ; /, i, front and back inner tubercle. 



be the distinguishing feature in the Odd-hoofed 

 animals. A five-toed genus with the middle toe in 

 this position has, as we have seen, been preserved 

 in the Coryphodon from the Eocene formation. 

 Now, as the lowest known tapir-shaped animals 

 possess at most four toes, the unknown primary 

 forms must, of course, be looked for in the secon- 

 dary divisions. The tapir, in addition to having 

 lost the inner toe, has also lost the fifth toe ; this 



