298 TEETH OF nUMINANTS. 



mistaken for those of a ruminant, and have been referred 

 to the genus Moschus. One of these interesting transitional 

 extinct quadrupeds, described in the Geological Journal^ 

 for 1847, under the name of Dlchodon^ had forty -four teeth 

 in one uninterrupted series, and of the same kinds, as in 

 the anoplothere; but the teeth there marked ^j4, and 

 m 1, upper jaw, I have ascertained to b( 



TEETH OF RUxMINANTS. 



The even-toed or artiodactyle Ungulata, superadd the 

 characters of simplified form and diminished size to the 

 more important and constant one of vertical succession in 

 their premolar teeth. These teeth, in the ruminants, re- 

 present only the moiety of the true molars, or one of the 

 two semi-cylindrical lobes of which these teeth consist, 

 wdth at most a rudiment of the second lobe. An ana- 

 logous morphological character of the premolars will be 

 found to distinguish them in the dentition of the genus 

 Sus (Fig. 75, 2)2, pS, p 4), in the hippopotamus, and in the 

 phacochosrus, or wart-hog, where the premolar series is 

 greatly reduced in number ; yet this instance of a natural 

 affinity, manifested in so many other parts of the organi- 

 zation of the artiodactyle genera, has been overlooked in 

 F. Cuvier's work, above cited, although it is expressly 

 designed to show how much zoological relations are 

 illustrated by the teeth. 



Most of the deciduous teeth of the ruminants resemble 

 in form the true molars; the last, e. g. has three lobes in 

 the lower jaw like the last true molar. When, therefore, 

 the third grinder of the lower jaw of any new or rare 

 ruminant shows three lobes, the crowns of the premolars 



