The American Naturalist. 



(general Kotes. 



GEOLOGY AND PALEONTOLOGY. 



The Eocene of the United States. 1 — The present essay is the 

 fourth of a series devoted to the discussion of the correlations of the 

 formations found in the different parts of the country with one another, 

 and with formations in other countries ; and to the discussion of the 

 principles of geologic correlation in the light of American phenomena. 

 Mr. Clark thus describes the scope of the work. 



" This essay comprises, first a general discussion of the lin 

 the term Eocene as employed in American geology. The two-fold 

 character of the Tertiary (1. Eocene, 2. Neocene) in America is 

 insisted on. 



After a somewhat extended review of the literature, in which the 

 various opinions upon disputed points are especially considered, a 

 general study of the Stratigraphical, paleontological, and topographi- 

 cal characteristics of the Eocene in the various portions of the country 

 is undertaken. 



The description of the Eocene of the United States falls naturally 

 into the three distinct regions, viz: The Atlantic and Gulf Coast 

 region ; the Pacific Coast region, and the interior region. 



Following a study of the stratigraphical relations of the Eocene of 

 the Atlantic and Gulf Coast region, an attempt is made to correlate 

 the very diverse formations of this great area. Four provinces are 

 provisionally established (1. New Jersey province, 2. Maryland- 

 Virginia province, 3. Carolina Georgia province, 4. Gulf province,) 

 though fuller knowledge may break down their bounds. The general 

 similarity of the deposits and their fossils to extra- American Eocene is 

 shown, but detailed correlation is not considered feasible. 



The meager knowledge of the Pacific Coast Eocene precludes any 

 general discussion of the stratigraphical and paleontological relations 

 of that horizon. The local peculiarities, shown both in fossils and 

 deposits, are referred to, and the close relationship existing between 

 the Eocene and Cretaceous is dwelt upon. Their separation 

 matter of some uncertainty with our pre; 

 bulletin of the United States Geological Sur\ 

 papers. Eocene. William Bullock Clark. 



Certain 



