| IDEAL SECTION OF EARTH’S CRUST | ||||
|---|---|---|---|---|
| ERAS | AGES | PERIODS | STRATA | |
| BYCHOZOIC | MAN | QUATERNARY | TERRACE, CHAMPLAIN, GLACIAL | |
| CENOZOIC | MAMMALS | TERTIARY | PLIOCENE, MIOCENE, EOCENE | |
| MESOZOIC | BIRDS | CRETACEOUS | ||
| REPTILES | JURASSIC | |||
| TRIASSIC | ||||
| ACROGENS AMPHIBIANS | CARBONIFEROUS | PERMIAN, CARBONIFEROUS, SUB-CARBONIFEROUS | ||
| PALEOZOIC | FISHES | DEVONIAN | CATSKILL, CHEMUNG, CORNIFEROUS, Etc. | |
| INVERTEBRATES | SILURIAN | LOW HELDERBERG, NIAGARA | ||
| ORDOVICIAN | LORRAINE, TRENTON, CHAZY | |||
| CAMBRIAN | POTSDAM, ACADIAN, GEORGIA | |||
| EOZOIC | ALGONKIAN | KENESAW, HURONIAN, Etc. | ||
| ARCHAEAN | LAURENTIAN, Etc. | |||
| AZOIC ERA | ||||
FRONTISPIECE.