6 



GENEKAL OBSEliVATIONS. 



Table of the subdivisions of geological time. 



AGES. 



PERIODS. 



EPOCHS. 



Ccnozoic. 



*TERTIARY. 



PLIOCENE. 

 MIOCENE. 

 EOCENE. 





Mcsozoic. 



• CRETACEOUS. 





'JURASSIC. 



TRIASSIC. 



Carboniferous. 



?» PERMIAN. 





'CARBONIFEROUS, OR 

 COAL-MEASURES. 



Upper Coal-Measures. 



Middle Coal-Measures. 



Lower Coal-Measures. 



* SUBCARBONIFEROUS. 



Chester Limestone. 



Saint Louis Limestone. 



Keokuk Limestone. 



Burlington Limestone. 



* Kinderhook Group. 



Devonian. 



CATSKILL. 



1 



CHEMUNG. 



HAMILTON. 



CORNIFEROUS. 



Upper Silurian. 



ORISKANY. 





LOWER HELDERBERG. 



SALINA. 



NIAGARA. 



liower Silurian. 



* TRENTON. 



* Cincinnati. 



?* Utica. 



Trenton. 



* CANADIAN. 



Chazy. 



* Quebec. 



Calciferous. 



* PRIMORDIAL. 



* Potsdam. 



Acadian. 





ARCHAEAN. 





• The presence of the asterisk indicates that the period or epoch, as the case may be, is represented by fossils in the collections. 



