RUMINANTIA. 



353 



tyles (fig. 645). There is also the anomalous character that 

 " larmiers " or " tear-pits " existed below the orbits, as in the 

 CervidcB. Oreodon itself is a Miocene genus, as is the much 

 larger Eporeodon. In the Middle Miocene we have the 

 Oreodont genus Agriochosrus, which has strong relationships 



Fig. 645. — Grinding surface of the upper molars and prsemolars on tlie right side 

 of Oreodon major. Miocene, North America. (After Leidy. ) 



with the Hyopotamus of the European Eocene ; and the 

 family is continued into the Pliocene by the genera Mcry- 

 chyus and Merycochmrus, after which it disappears altogether. 



KUMINANTIA. 



The last section of the Artiodadyle Ungulates is the great 

 and natural group of the Ruminantia, or Euminant animals. 

 This section comprises the Oxen, Sheep, Antelopes, Giraffes, 

 Deer, Camels, &c., and is distinguished by the following- 

 characters : — 



The foot is what is called " cloven," consisting of a sym- 

 metrical pair of toes encased in hoofs, and looking^as if pro- 

 duced by the splitting into two equal parts of a single hoof. 

 In addition to these functional toes, there are usually two 

 smaller lateral digits placed at the back of the foot. The 

 metacarpal bones of the two functional toes of the fore- 

 limb, and the metatarsal bones of the same toes of the hind- 

 limb (except in Hyomoschus), coalesce to form a single bone, 

 known as the " canon-bone." The stomach is complex, and 

 is divided into several compartments, this being in accord- 

 ance with their mode of eating. They all, namely, ruminate 

 or " chew the cud " — that is to say, they first swallow their 

 food in an unmasticated or partially-masticated condition, 

 and then bring it up again, after a longer or shorter time, in 

 order to chew it thoroughly. 



VOL. II. Z 



