192 



UNGULATA 



ORDER YII 



metapodials much stouter than the completely developed lateral ones, distinct or fused 

 into a cannon bone. Reduction of lateral digits adaptive. Stomach with three 

 compartments. 



To the Tragulidae belong only small forms, the largest of which attain 

 the size of the roe-deer. They appear in the Oligocene of Europe, and are 

 the descendants of Dichohune-like forms. In the Miocene they are still rarer 

 and represented only by the genus Borcatheriiim, the ancestor of Hyaemoschns 

 now living in western Africa. The ancestor of Tragulus, now living in 

 southern India and the Malayan Islands, still remains to be discovered. 



The delicate chevrotains occupy a position intermediate between the 

 Dichobunidae and Cervidae. Their hornless skull, distinct bones in the forearm, 

 incomplete fusion of the principal metapodials, presence of lateral metapodials, 

 and the elongated trenchant premolars are all primitive characters. On the 

 other hand, the cheek teeth so closely resemble those in the Cervidae that 

 only by the closest scrutiny are they distinguishable, being somewhat more 

 robust and less complex in structure. The suppression of the superior 

 incisors is also a distinctly ruminant character. In the two existing genera, 

 the diflfuse placenta and the stomach with three compartments prove that in 

 their difterentiation, at least, the Tragididae are less progressive than the 

 ruminants, and constitute an independent group beginning in the Oligocene. 

 In special development they are nearly allied to the Cervidae, while the 

 Gelocinae represent the ancestors of some Old World Cavicornia and all 

 Cervicornia, with which they are connected by the hornless genera Amphitragulus 

 and Dremotherium. The geographical range of the Tragulidae is limited to 

 the Old World ; Europe, Africa, and Asia. 



Subfamily 1. Tragulixae. 



Occiptd high and narrow. Tympanic bullae filled with cancellated bony tissue. 

 Premolars simple, elongated. Inferior molars with oblique ridges running downward 



Fio. 2G4. 



Dorcatherium naui Kaup. Lower Pliocene, Eppelsheim, 

 Hesse Darmstadt. Skull and lower jaw. 1/3. (Alter 

 Kaup.) 



Fig. 265. 



Dorcatherium crassum Lartet sp. Upper 

 Miocene, Gunzburg. A, Upper P-i, M-, il/3. B, 

 Lower P3, Af], J/o. Vi- 



from the apex of the protoconid, usually also with ridge on the metaconid. Superior 

 molars toith strong cingulum ; lateral metapodials complete in manus and pes. 

 Cuboid, navicular, and later also the cuneiforms fused into one bone. 



Fossil in the Oligocene, Miocene and Lower Pliocene of Europe, and in 



