XII 



LIFE OF TERTIARY PERIOD 229 



of some of the later forms. After these come the Tetra- 

 belodons from the Miocene beds of France and North 



Recent 

 Pleistocene 

 Ujifier Pliocene 



ELEPHA3 

 (short chin) 



Lower Pliocene TETRABELODON 



[LONGIROSTRTS STAGE] 

 Ufifier Miocene (shortening chin) 



Middle Miocene TETRABELODON 



fANGUSTIDENS STAGE] 

 Layer Hiocen e (long chin) 



UfifierOligocene 



Migrationjrom Africa 

 into Eurofie -Asia 



Lower Qligoce ne ?} 

 UpfierEocene J 

 Middle Eocene ( 

 Lower Eocene 



PALAEOMASTODON 

 (lengthening chin) 



MOERITHERIUM 

 (short chin) 



FIG. 82. DIAGRAMS SHOWING INCREASE OF SIZE AND ALTERATION IN 

 FORM OF SKULL AND TEETH OF THE PROBOSCIDEA SINCE EOCENE 

 TIME. (B.M. Guide.) 



