During the last decade of the 19th Century, considerable attention was focused upon the classification and description of Cretaceous rocks in western Kansas. Some rock unit names proposed during this time were synonyms and were discarded (i.e., Lisbon for Pierre; Osborne for Fort Hays), some were nongeographic in origin (i.e., Bituminous Shale horizon for Graneros; Hesperornis beds for part of the Smoky Hill), and some stand to this day (i.e., Blue Hill; Lincoln). In 1896, G. K. Gilbert divided the Benton into three formations (Graneros Shale, Greenhorn Limestone, and Carlile Shale) on the basis of exposures in the foothills of the Rocky Mountains of Colorado. Logan (1899) recognized equivalent units in the Kansas Benton, but Gilbert's names for these units were first used in the State by Darton (1904, pl. 36). Subdivision of formations and naming of member units in the Upper Cretaceous in Kansas has followed a rather haphazard course; one formal name appeared as early as 1876 (Fort Hays Limestone) and the latest appeared in 1942 (Janssen Clay Member of the Dakota Formation). In 1897 and 1898, under the direction of Erasmus Haworth, work in western Kansas by the State Geological Survey culminated with publication of several major reports on the stratigraphy and paleontology of the Upper Cretaceous rocks. Through the years of the present century, shorter paleontological papers have appeared steadily and treat a broad spectrum of vertebrate, invertebrate, and paleobotanical subjects. The next episode in the saga occurred in the mid-twenties and thirties when the State Geological Survey published a number of geological reports on several counties lying across the Cretaceous outcrop. Especially notable among these reports are those for Russell County (Rubey and Bass, 1925) and Wallace County (Elias, 1931). In more recent years, from about 1940 to date, brief summaries of Upper Cretaceous stratigraphy have accompanied a number of county reports concerned with geology and ground-water conditions within the Cretaceous out- crop in Kansas. Detailed stratigraphic reports have been published for the Dakota Formation (Plummer and Romary, 1942), Carlile Shale (Hattin, 1962), and Graneros Shale (Hattin, 1965, in press) and further studies of this kind are in progress. Other aspects of Cretaceous gology that have received attention recently include subsurface stratigraphy (Merriam, 1957a; Merriam and others, 1959), cross-stratification (Franks and others, 1959), and mineral commodities ranging from chalk to uranium. Interest in Upper Cretaceous rocks of western Kansas shows no sign of decline, despite many years of study by a legion of investigators. Discoveries of new fossils occur fre- quently and many invertebrate species remain undescribed. Petrographic study of some rock units has scarcely begun, and geochemical analysis of both rocks and faunas is needed badly. Studies of depositional environment and paleoecology must be considered far from complete and offer much challenge for researchers in years to come. 3