PEDIGREE OF MAMMALS. 273 
of the placenta might similarly arise in different ways, 
just as it has been variously developed in the well-sub- 
stantiated 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 Probos- 
cide. 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 carnivorous genera. 
In our exposition of the geographical distribution of 
animals, we derived instruction from Riitimeyer with 
Rhinoceroses. ‘Tapirs. Horses. 
\ 
Hipparion. 
Macrauchenidz. 
Anchitherium. 
Palzeotheridze. 
reference to the relationships of the Ungulata in 
particular. In no other division do we possess such 
