xiv CONTENTS 



THE MESOZOIC ERA 



CHAPTER XXIII 

 THE TRIASSIC PERIOD 



FORMATIONS AND PHYSICAL HISTORY 678 



Eastern Triassic Newark series, 678. In the West, 684. On the 

 Pacific slope, 685. Climatic conditions, 686. Close of the Trias, 

 687. Foreign Triassic, 687. 



LIFE OF THE TRIASSIC PERIOD 690 



Plant life, 691. Land animals, 691. Marine life, 695. 



CHAPTER XXIV 

 THE JURASSIC PERIOD 



FORMATIONS AND PHYSICAL HISTORY 702 



Eastern part of the continent, 702. Western interior, 702. 

 Pacific coast, 705. Thickness, 707. Surface distribution and 

 position of beds, 707. Close of the Jurassic, 707. Orogenic 

 movements, 707. Foreign Jurassic, 708. Jurassic coal, 709. 

 Climate, 710. 



LIFE OF THE PERIOD 710 



Marine life, 711. Land life, 719. 



CHAPTER XXV 

 THE COMANCHEAN (LOWER CRETACEOUS) PERIOD 



INTRODUCTORY 727 



FORMATIONS AND PHYSICAL HISTORY 728 



Atlantic and Gulf Border regions, 728. Texas- Mexico region, 731. 

 Northern interior, 732. Pacific border, 733. Close of the 

 Comanchean (Lower Cretaceous) period in North America, 735. 

 Lower Cretaceous in other continents, 736. 



LIFE 737 



Terrestrial vegetation, 737. Land animals, 739. Fresh-water 

 fauna, 739. Marine faunas, 740. 



CHAPTER XXVI 

 THE CRETACEOUS PERIOD 



FORMATIONS AND PHYSICAL HISTORY 742 



Atlantic border region, 742. Eastern Gulf border, 744. Western 

 Gulf region, 746. Western interior, 746. Pacific coast, 752. 

 Close of the period, 752. Upper Cretaceous of other continents, 

 755. Climate, 759. 



LIFE OF THE (UPPER) CRETACEOUS 759 



Land plants, 759. Land animals, 762. Sea life, 765. 



