CONTENTS. Xlll 



II. PALEOZOIC TIME— (continued). PAGE 



III. Carboniferous Age 305 



Subdivisions and American Distribution. 305 



1. Subcarboniferous Period 306 



1. American 306 



2. Foreign 318 



3. Disturbances preceding the Carboniferous Pe- 



riod 320 



2. Carboniferous Period 321 



1. American 321 



1. Epoch of the Millstone Grit 321 



2. Epoch of the Coal Measures 322 



[Review of the Class of Reptiles 343 



2. Foreign 352 



3. General Observations on the Carboniferous 



Period 359 



3. Permian Period 369 



1. American 369 



2. Foreign 372 



IV. General Observations on the Paleozoic Ages 377 



1. Rocks — Sections of the American Palaeozoic Forma- 



tions in different States 377 



2. American Geography 386 



3. Oscillations of Level — Dislocations 388 



4. Life 394 



Disturbances closing Palaeozoic Time 403 



1. American 403 



2. Foreign 412 



Transition from the Palaeozoic to the Mesozoic 414 



III. MESOZOIC TIME 413 



Reptilian Age 414 



1. Triassic Period 414 



1. American 414 



[Review of the Class of Insects 420 



[Review of the Class of Mammals 421 



2. Foreign 433 



3. General Observations 438 



2. Jurassic Period 444 



1. American 444 



2. Foreign 446 



3. General Observations 465 



