ee EVOLUTION OF THE EARTH 



array of modernized animals. The era closes with a very 

 decided glacial climate and another marked change in the 

 animal world, out of which man rises to his present primacy 

 among organisms. Geologists therefore call the present time 

 the Psychozoic era or the Age of Reason. 



; OF COAL 

 FORMATION DASHED 





\T^r\ 



Fig. 10. — The marine inundation in Pennsylvanian time. Coal 

 swamps in partially marine areas indicated by broken lines. 

 From the Pirsson-Schuchert * 'Text-book of Geology,*' pub- 

 Kshed by John Wiley & Sons, Inc. 



