CONTENTS. 



VOLUME III. 

 MESOZOIC ERA. 



CHAPTER XII. 



THE TRIASSIC PERIOD. 



PAGE 



Formations and Physical History. ........... 1 



The Triassic System (Newark Series) of the East. , . . 2 



Distribution, 2 The rocks of the Newark series, 4. The 

 conglomerates, 4. The sandstone and shale ; 6. Conditions 

 of origin, 7. Former extent, 9. Subdivisions. 10. Igneous 

 rocks associated, 10. Structure, 11. Thickness, 17, Corre- 

 lation, 17. Physiography of the Newark of New England and 

 New Jersey, 19. 



The Triassic in the West. . . 24 



The deposits of the western interior, 24. Thickness, 27. 

 The Triassic system on the Pacific slope, 27. 



Climatic Conditions. 29 



Close of the Trias. . . . 29 



Foreign Triassic. 30 



Europe, 30. Germany, 31. England, 33. Sweden, and 

 Russia, 34. Southern Europe, 35. Asia, 37. South America, 

 37. Africa and Australia, 38. 



The Life of the Triassic Period , 38 



The Plant Life 38 



The dominance of the gymnosperms, 38. 



The Land Animals. 41 



The rise of the dinosaurs, 43. The advanced differentia- 

 tion of the chelonians, 43. The advent of the non-placental 

 mammals, 44. The reptiles go down to sea, 45. 



The Marine Life. 48 



The transition tracts, 48. The transition faunas, 49. 

 General nature of the faunal change, 50. The earlier Triassic 



iii 



