THE EOCENE OF EUROPE AND NORTH AMERICA 



173 



Cer. 



Fig. 71. — Brain proportions in archaic (left) and modern (riKht) mammals of similar size. 

 Olfactory lobes (dots), cerebral hemispheres (oblique lines), cerebellum and medulla (dashes). 



Arctocyon A Canis 

 Phenacodus B Sus (Domestic) 



Coryphodon C Rhinoceros 



Uintatherium D Hippopotamus. 



