162 THE CLASSIFICATION OF PLANTS 
General Table of Geologic Time Divisions 
‘ Present—All phyla including highest Flow- 
ering Plants. | 
CEN OZOIC Pleistocene—Nearly as at present. 
(Tertiary)... { Pliocene 
Miocene } Increase in higher Flowering 
Oligocene Plants. 
Eocene—Increase of Flowering Plants. 
Upper Cretaceous—Rapid increase of lower 
Flowering Plants. 
Lower Cretaceous (Comanche or Shastan)— 
Appearance of lower Flowering Plants. 
Jurassic—Ferns, Cycads, Conifers. 
Triassic—Ferns, Cycads, Conifers. 
Permian—Ferns, Calamites, Lycopods, Cy- 
cads, Conifers. 
Coal Measures, or Pennsylvanian—Terns, 
Calamites, Lycopods, Cycads. 
Subcarboniferous, or Mississippian— Ferns, 
PALHOZOIC..... { Calamites, Lycopods, Cycads. 
Devonian—Ferns, Calamites, Lycopods, Cy- 
cads. 
Silurian—Probably some land vegetation. 
Ordovician—Probably some land vegetation. 
Cambrian—Apparently some higher algae. 
| Keweenawan Probably 
PROTEROZOIC... | Animikean (Upper Huronian) } only simple 
Huronian algae. 
ArcHeozoic... Archean Complex—Probably only very sim- 
ple algae. 
MESoOzoIC..... . 
