20 



TRANSACTIONS OF THE 



[NOV. 10, 



daetyla. They have affinities with the Rodentia (re-curved spine 

 on the scapula, and two anterior ven?e cavfe), and also with the 

 Sii'enia; the limbs are low in structure. 



General Characteristics of the Proboscidia. — The living 

 forms stand by themselves, alone, unique. In some points they 

 have a low or generalized structure. They are highly special- 

 ized in other points, as the skull, teeth and proboscis. Their 

 ancestral farms are found in the Eocene. 



Geological History of the Proboscidia. — 



The greater number and variety are found in the geological 

 formations of the East. 



Elephas is an Old World type which appeared in America 

 in the Pliocene (two species). In the Post-Pliocene (Pleisto- 

 cene) the Elephas prionigefiius ranged over all the Arctic region. 



