PEDIGREE OF MAMMALS. 



273 



has been variously developed in the well-substantiated 

 division of the Ungulata. To corroborate our view by- 

 example, we are certainly unable to make any positive 

 statements as to the derivation of the Proboscidge. It is, 

 however, none the less certain that nothing positive is 

 implied by the customary classification by reason of their 

 zOnary placenta. But we shall more nearly approach the 

 truth if we place this branch of unknown origin typically 

 nearer to the Ungulata than to the beasts of prey. If, 

 moreover, as non-deciduate mammals, the Cetacea are 

 held to be more closely allied to the Ungulata than to 

 the Carnivora, which are -deciduate, — in our eyes, this 

 circumstance is not decisive, as more important reasons 

 argue that the Cetacea were first developed from carniv- 

 orous genera. 



In our exposition of the geographical distribution of 

 animals, we derived instruction from Riitimeyer with 



Rhinoceroses. Tapirs. 



Horses. 



Hipparion. 



Anchitheriiim. 



Palasotheridas. 



Macrauchenidse. 



reference to the relationships of the Ungulata in 

 particular. In no other division do we possess such 

 abundant fossil material. In the older Tertiary strata 



