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their formation designations, the Dakota, Eagle Ford, Austin, Taylor, and Navarro, respectively.

As the development progressed the writer used such temporary names for the beds as were convenient, changing them from time to time as was thought expedient. These names were often paleontologic terms and were applied with the intention of revising them for the final report upon the subject.

In the classification herein presented, the author has endeavored to refine this nomenclature by using appropriate geographic terms for all the beds. For this purpose, where possible, mononyms taken from recognizable localities have been employed, and the paleontologic and mineralogic names as hitherto used have been abandoned. Thus it is that the terms "Dinosaur sands," "Caprina limestone," "Exogyra texana beds," "Exogyra arietina¹ clays," "Fish beds," "Exogyra ponderosa¹ marls," Hippurites limestone," etc., of earlier writings have been replaced by appropriate geographic names. Even some geographic names originating in the author's earlier writings have been abandoned. For "Timber Creek beds," which had been previously used for a different horizon in New Jersey, Lewisville beds has been substituted, and for "Barton Creek limestone," which, besides being preoccupied, is not a good locality name, Edwards limestone has been substituted. Finally, as this work goes to press it is discovered that the name "Shoal Creek" must be abandoned because it has been previously applied to another formation in Indiana, and the term "Buda" is substituted therefor. While there has been an endeavor to use the same name for the same formation in different sections, in some cases it has been necessary to use purely local names for formations apparently synchronous with beds of other sections, because the beds, through gradual change along their strike, have become entirely different in composition.

This section runs northward from Sherman through Denison to the vicinity of Nida, Indian Territory, across Red River. The sequence of the beds is partially duplicated north and south of Red River (see Pl. LII), owing to the downthrow of the Preston fault, which crosses the section approximately along the course of Red River. The Cooks Springs fault, south of Denison, cuts out much of the Upper Cretaceous strata. "

These terms have been wrongly abbreviated into the "Texana," "Arietina," and "Ponderosa" beds by certain writers.