454 THE AMERICAN NATURALIST [Vol. LVI 



Amphibious and swamp-living stock 



I. MCEEITHERIOIDEA (Moeritheres) 



1. Moeritheriini/ amphibious or swamp-living forms 



known in the Upper Oligocene of Africa. 

 II. DmOTHEEIOIDEA (Dinotheres) 



2. Dinotheriini,* large amphibious forms frequenting the 



Ubid. 



rivers of southern Eurasia throughout the 

 Miocene to the close of the Pliocene. 

 Forest and savanna grazers 



III. MASTODOi^TOIDEA (Mastodonts and Bunomasto- 

 donts) 



Mastodoxtid^ or " true mastodonts," including the sub- 



3. MastodontinfE, springing from Palceomastodon of 



the Oligocene of ISTorth Africa, and terminat- 

 ing with Mastodon americanus of the Pleisto- 

 cene forests of North America; grinders 

 lophodont, lacking trefoils. 



4. Serridentinfe,' first known in the Middle Miocene 



of France and Switzerland, spreading over 

 into India and North America; lacking the 

 trefoils 



BuxoMASTODONTiD^, the bunomastodonts, springing from 

 forms similar to the PMomia of North Africa 

 and separating into four main divisions : 

 G. Longirostrina?, typical long-jawed bunomasto- 

 donts arising in North Africa (Phiomia), 

 spreading all over southern Europe, Asia, and 

 North America. ^ ^ 



dean region of South America and spreading 

 over the South American continent, distin- 

 guished by the loss of the lower tusks and the 

 abbreviation of the jaw. 



7. Rhynchorostrina?, beaked bunomastodonts, known 



only in the southern United States and north- 

 ern Mexico, with powerful downturned upper 

 and lower tusks. 



8. Brevirostrinse, short-jawed bunomastodonts, which 



imitate both the true mastodonts and the 

 elephants in the abbreviation of the lower 

 jaw and the early loss of the inferior tusks. 

 3 Herluf Winge, 1906, p. 172. 



with Avhich its ineiiibors are generally placed by European paleontologists. 



