510 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



indeed, the first specimen of this genus collected was referred 

 to a large species of fNesodon by Owen. On the other hand, 

 the resemblance to the rhinoceros teeth is very decided, and 

 has led several writers to postulate a relationship between the 

 fastrapotheres and the rhinoceroses. The lower molars were 



Fig. 254. — Head oi fAstrapotherium magnum. Santa Cruz. Re- 

 stored from a skull in the museum of Princeton University. 



of the bicrescentic pattern so frequently met with already ; 

 these teeth were very narrow in proportion to their length 

 and strongly suggest those of ^Metamynodon, the supposedly 

 aquatic rhinoceros of the North American Oligocene (p. 

 346). It may be confidently inferred that so small a number 

 of premolars was due to reduction from a full series, and this is 

 confirmed by the milk-dentition, in which the premolars were |. 



