V. S. GEOLOGICAL SUUVEY 



MONOGKAPH 55 PLATE XLIX 



BRAIN OF EOCENE MAMMALS COMPARED WITH THAT OF MODERN AND OTHER MAMMALS 



Archaic forms m left column; modernized forms in right column. Olfadlory lobes represented by dots; ce: 

 black lines; cerebellum and medulla by dashes. A, Ardlocyon. Eocene flesh eater; Ca-nis, the dog moderr 

 nacodus. Eocene primitive ungulate; Sus, the domestic pig. C, Coryphodon, Eocene ungulate; 'Rhinoce 

 of same s,ie. D, Uintatherium, massive Eocene ungulate. E, Menodus gigantens, Oligocene titanothere 

 natural size 



ebral hemispheres by 

 flesh eater. B, Phe- 



OS, living rhinoceros 

 All over one-fourth 



