xxii CONTENTS. 



PAQE 



The ostracoderms, 483. The cyclostomes, 486. The wide 

 deployment of the fishes, 486. The associated arthropods, 

 490. Fresh-water mollusks, 490. 



III. The Land Life 490 



The land plants, 491. The insects, 494. Other terrestrial 

 forms, 495. 



CHAPTER IX. 

 THE MISSISSIPPIAN (EARLY CARBONIFEROUS) PERIOD. 



Formations and Physical History 498 



Subdivisions. 500 



East of the Great Plains 500 



The Kinderhook series, 501. The Osage or Augusta 

 series, 501. The St. Louis formation, 502. The Kas- 

 kaskia (Chester) beds, 503. 



In the Great Plains 504 



West of the Great Plains 505 



Igneous Activity 507 



Close of the Period 507 



Reasons for Regarding the Mississippian a Distinct System 508 



Thickness of the Mississippian System. . ., 510 



The Lower Carboniferous of Other Continents 511 



Igneous rock, 515. Thickness, 516. Close of the 

 Early Carboniferous period in Europe, 516. Other 

 continents, 517. 



Climate 518 



The Life of the Mississippian (Sub-Carboniferous) 518 



I. The Marine Faunas 518 



1. The Kinderhook Fauna 519 



The resilience of the crinoideans, 519. Transition 

 in the aspect of the brachiopods, 519. Other features, 

 521. 



2. The Osage Fauna 521 



The climax of the crinoids, 522. The scantiness 

 of the corals, 523. Other features, 523. 



3. The Waverly Fauna 526 



4. The Great Basin Fauna 527 



5. The Genevieve (St. Louis-Kaskaskia) Fauna 529 



