PHYLETIC BRANCHES AMONG THE VERTEBRATES 177 



Lower 

 Miocene 



Burdigalian 

 Stages 



/ Brachyodu 

 \ onoidens 



Oligocene 



( Large animal equal in 

 , I size to an ordinary Rhino- 

 ' -j ceros : enamel of the 

 molars finely wrinkled, 



[ large triangular canines. 



Aquitanian Mutation still unknown in the fauna of 

 Stage Saint Gerand-le-Puy. 



t Size of 



Upper Stampian Brachyodus 

 Stage borbonicus 



Lower Stampian J Brachyodus 

 I porcinus 



Eocene 



Sannoisian 

 Stage 



Sannoisian 

 Stage 



.Ludian Stage 



Bartonian Stage 



large boar, 

 aquatic and carnivorous 

 animal : long canines 

 compressed, with ere- 

 ^ nellated edges. 



Size of small pig, cha- 

 racters much the same 

 as the above. 



/ Brachyodus j Identical with the last 

 \ porcinus \ as to molars. 



1 Species the size of the 



B. porcinus, but with 

 Brachyodus] slightly more bunodont 

 Cluai | molars ; probably repre- 

 sents a small lateral 

 shoot from the branch. 



