538 



CENOZOIC ERA— AGE OF MAMMALS. 



Some General Observations on the Tertiary Mammalian Fauna.— l. 



Size of Brain. — Lartet has shown that the train-cavity of some of the 



Fig. 920. 



Figs. 918-920. — Brains op Coryphodon, Dinocerap. and Brontotherittm, compared (after 

 Marsh): 918. Coryphodon, Skull and Brain, x £. 919. Dinoceras, Skull and Brain, x $. 920. 

 Brontotherium, Skull and Brain, x ^. 



