PREFACE. 



This work is a liistorical review of what we know of the Triassic, 

 Jurassic, Cretaceous and Tertiary formations of North America. It 

 is not exhaustive, yet it contains more information in regard to these 

 formations than will be found in any other single publication. In 

 compiling the work, the language of the various authors, whose books 

 are referred to, has been used wherever practicable, and when it has 

 been abridged the substance has not been changed. The author has 

 not had an opportunity to specially study any of these formations be- 

 yond that part which is embraced within the period of the drift. The 

 latter he has explored and studied, in its distribution, over man}' of the 

 States and a considerable part of Canada. 



He has undertaken to overthrow the glacial hypothesis, and now 

 submits the facts and the conclusions he has drawn to the learned of 

 this country and of Europe, and asks for their verdict. There is this 

 further fact to be remembered. If there was no glacial period in North 

 Ameiica, there was none in Europe. 



Only'a limited number of copies of the book has been published in 

 this form,, though it has appeared, in parts, in the last three volumes of 

 the Journal of the Cincinnati Society op Natukal History. 



