CONTENTS. 



Paga 



Letter of transmittal by Mr. G. K. Gilbert 7 



Outline of this paper 11 



Introduction. The state of opinion at the beginning of the present cen- 

 tury regarding the classification and naming of geologic formations 13 



Chapter I. The history and development of opinion regarding the classifica- 

 tion of rocks in the United States, from the time of William Maclnre to the 

 completion of the geological survey of the State of New York (1809-1843) 22 



Chapter II. The general application of the nomenclature of the New York 

 system as a standard of correlation in other parts of the United States 

 (1840-1851) 58 



Chapter III. Miscellaneous discussions regarding the correlation of Devo- 

 nian and Carboniferous formations in the central part of the United States 

 (1846-1887) 75 



Chapter IV. The differentiation of the Carboniferous system 83 



Chapter V. The Coal Measures or Pennsj r lvanian series : The development of 

 its nomenclature and classification in the Appalachian Province (1836-1888). 108 



Chapter VI. The conglomerates and Lower Carboniferous formations of the 

 Appalachian Province 121 



Chapter VII. The Chemung-Catskill problem : The history of the discus- 

 sions concerning the correlation of the Chemung-Catskill formations in the 

 northern part of the Appalachian Province 135 



Chapter VIII. The Lower Carboniferous or Mississippian series: The devel- 

 opment of the nomenclature and classification of the Lower Carboniferous 

 formations of the Mississippian Province (1821-1874) 173 



Chapter IX. The Waverly problem : The history of the discussion concern- 

 ing the correlation of the Waverly, Marshall, Goniatite limestone, Kinder- 

 hook, and Choteau formations (1838-1888) 193 



Chapter X. The Permian problem: Discussions relative to the correlation 

 of the Permian in Kansas and Nebraska and other parts of the United States 

 (1858-1886) 213 



Chapter XL Devonian and Carboniferous correlations in the Western and 

 Northern Provinces of North America 226 



Chapter XII. The Acadian Province : The correlations and classifications 

 of the Upper Paleozoic formations in the Acadian Province 258 



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