From outline: The primary object of this bulletin is the presentation of a summary of our present knowledge of the North American Cretaceons and a discussion of the system as it is developed on this continent, discussion of or direct reference to the details of the system as it is developed in other parts of the world being omitted.

From outline: This essay comprises, first, a general discussion of the limitations of 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 topographical characteristics of the Eocene in the various portions of the country is undertaken.