3 CONTENTS. 



Page. 

 Chapter IV— Continued. 



Section at Hemmingford •- 343 



Section at Keeseville and in Au Sable Chasm 343 



Section at Whitehall 344 



Section at Saratoga - 346 



Western border or Rocky Mountain sub-Province 347 



South Dakota 347 



Wyoming ■ 349 



Colorado 351 



Southwestern sub-Province 354 



Texas 354 



Arizona 356 



Resume" 357 



Synopsis of the Cambrian group 359 



Base of Cambrian 362 



Summit of Cambrian 362 



Sedimentation of the Cambrian group 363 



Subdivision of the Cambrian 370 



Comparison with the Cambrian rocks «f other countries 373 



Europe 373 



Scotland 376 



Ireland 377 



China 377 



India 378 



Australia 378 



South America 379 



Chapter V. Problems for investigation and settlement 380 



Local problems 380 



Newfoundland 380 



Nova Scotia 380 



New Brunswick 381 



Maine and New Hampshire 381 



Eastern Massachusetts 381 



New York 381 



Adirondack sub-Province 381 



Vermont 381 



Canadian extension 382 



New Jersey 382 



Pennsylvania , 382 



Virginia 383 



North Carolina 383 



Tennessee 383 



Georgia and Alabama 383 



Utah and Nevada 384 



Colorado 384 



Rocky Mountains 384 



Arizona 385 



Upper Mississippi Valley 385 



Missouri 385 



Texas 385 



Problems affecting our knowledge of the Cambrian group as a whole or in 



large parts 385 



Problems of nomenclature and classification 388 



The name 388 



The limit of the group 388 



