376 THE ANATOMY OP VERTEBEATED ANIMALS. 



sition from the non- Ruminant to tlie Ruminant gi-oups, 

 or ratlier tlie common stem of both, is furnished by the 

 AnojylotheridcB. 



c. The family of the Anoplotheridce exclusively contains 

 extinct Mammals belonging to the eocene and miocene 

 epochs. They are most conspicuously distinguished by the 

 circumstance that the teeth, of which there are eleven on 

 each side, above and below, in the adult dentition, are not 

 interrupted by any gap in front of and behind the canine, 

 as they are in the preceding genera, but form an uninter- 

 rupted and even series, as in Man. 



The dental formula of the adult Anoplotherium is 



^' Fa *'■ Ta P''"^' ^4 ™' 3^' STiPPOsing that the first pre- 

 molar is really such, and not a persistent milk molar. 



The upper and lower molars hare the general structure 

 of those of the Rhinoceros ; but the laminae of the vipper 

 are bent more backwards into parallelism with the outer 

 wall, and a strong conical pillar is developed on the inner 

 side of the anterior lamina. The skull resembles that of 

 the Ruminant Tragulidce in stmcture, but the orbit is in- 

 complete behind. The rest of the skeleton paj-tly resembles 

 that of the Pigs, and partly that of the Ruminants.* 



In Xiphodon and Cahiotherium, which are ordinarily com- 

 prised among the AnoplotheridcB (though, in all probability, 

 they are true Ruminants of the Traguline group), the orbit 

 is complete, and both upper and lower molars put on the 

 Ruminant characteristics. In dentition, Cainotherium differs 

 from a Ruminant only in possessing all the upper incisors, 

 while no existing adult Ruminant has more than the outer 

 upper incisors. We are of course unacquainted with the 

 structure of the stomach in these animals, but they so 

 closely resemble Ruminant Artiodactyla that it is highly 

 probable they may have possessed the faculty of rumination 

 in a more or less perfect degree. 



* In Anoplotherium secundarium the digit ii. is developed in each 

 foot, though not nearly so long as Hi., which is nearly symmetrical in 

 itself. There is an approach to the same structure in the manus of 

 Cainotherium. 



