4 PREFACE. 



petrology has elucidated much of the obscure in the constitution, relations, 

 and origin of rocks. 



Moreover, America, from early in the century, has been receiving 

 instruction through the development and parallel progress of the Science 

 in Europe and other lands. 



The first edition of this Manual owed much to the advice of the able 

 paleontologist, Y. B. Meek, and also to his skill as a draftsman; and the 

 work still bears prominent evidence of his knowledge, judgment, and scru- 

 pulous exactness, traits which give a permanent value to all the results of 

 his too soon ended labors. 



In this new edition, the Paleozoic paleontology is largely indebted to 

 Professor C. E. Beecher and Professor H. S. Williams ; the Jurassic, 

 of western America, to Professor A. Hyatt ; the Cretaceous, to Professor 

 Hyatt, Mr. T. W. Stanton, Mr. R. P. Whitfield, and Professor E. T. 

 Hill ; and the Tertiary, as regards the Invertebrates, to Professor G. D. 

 Harris. With respect to the Vertebrates of the Jurassic, Cretaceous, and 

 Tertiary, very valuable aid has been received from Professor Marsh, and 

 also in the part on Tertiary Mammals from Professor W. B. Scott. The 

 account of the arrangement and distribution of the Jurassic and Cretaceous 

 rocks of western America was prepared with the assistance of Mr. J. S. 

 Diller ; and that with regard to the marine Tertiary of the country was 

 chiefly written for its place by Professor Harris. I am further indebted 

 to Professor A. E. Verrill for his revision of the pages on the Animal 

 Kingdom. 



Moreover, the replies to requests for information have placed me under 

 obligation to almost all the geologists of the Continent, those of Canada as 

 well as the United States, — and especially to Sir William Dawson, Mr. 

 A. R. C. Selwyn, Dr. G. M. Dawson, Mr. Clarence King, Mr. C. D. 

 Walcott, Professor N. S. Shaler, Professor S. H. Scudder, Mr. 

 Prank Leverett, Professor R. T. Hill, Professor W. Upham, Pro- 

 fessor G. P. Wright, Professor J. J. Stevenson, Mr. Wm. H. Dall, 

 Dr. C. a. White, and Professor J. P. Iddings. 



Throughout this volume, the dates of papers containing cited facts or 

 views are often stated- If a condensed bibliography, containing in brief 

 form the titles of the most important geological and paleontological works 

 and papers, arranged under the year of publication, were accessible to the 

 student, these dates would be a sufficient means of reference. Without 

 such a Bibliography they may serve as a help in consulting, besides Reports 

 of Geological Surveys, the serial scientific publications. It is best to com- 

 mence the search with the periodical containing the most geological papers, 

 notes, and book notices, and follow on with the others. The American 

 Journal of Science commenced in 1818 ; the American Naturalist, in 

 1868 ; the American Geologist, in 1888 ; the Bulletin of the American 

 Geological Society, in 1890; the Journal of Geology, Chicago, in 1893. 

 Then refer to the Proceedings and Memoirs of American Scientific Soci- 



