Produced by Simon Gardner, Chris Curnow, Joseph Cooper and the Online Distributed Proofreading Team at https://www.pgdp.net Transcriber's Notes This Plain Text version represents italic typeface with _underscores_ and small caps typeface with ALL CAPS. Only a few changes were necessary to the text in the case of typographical errors, as follows: Page 623 Table 3 column heading: changed "or" to "of" (Number of specimens). Page 625: changed "percent" to "per cent" (92 per cent of the time). * * * * * UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 17, No. 15, pp. 613-629, 6 figs. May 14, 1968 Morphological Variation in a Population of the Snake, Tantilla gracilis Baird and Girard BY LAURENCE M. HARDY AND CHARLES J. COLE UNIVERSITY OF KANSAS LAWRENCE 1968 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Frank B. Cross, Henry S. Fitch, J. Knox Jones, Jr. Volume 17, No. 15, pp. 613-629, 6 figs. Published May 14, 1968 University of Kansas Lawrence, Kansas PRINTED BY ROBERT R. (BOB) SANDERS, STATE PRINTER TOPEKA, KANSAS 1968 31-9422 Morphological Variation in a Population of the Snake, Tantilla gracilis Baird and Girard By LAURENCE M. HARDY AND CHARLES J. COLE INTRODUCTION Variation of selected taxonomic characteristics of flat-headed snakes (_Tantilla gracilis_ Baird and Girard) from several midwestern states was studied by Force (1935), but she did not attempt a comprehensive evaluation. Taylor (1936) reported on variation in _T. gracilis_ from various localities in Kansas; Kirn, Burger, and Smith (1949) studied selected structures of specimens of _T. gracilis_ from throughout its range. The present study was undertaken to determine the variation in both currently used and potential taxonomic characteristics of _T. gracilis_ from one locality. We are thankful to Charles W. Myers, Gorgas Memorial Laboratory, for suggestions concerning characteristics examined. We are indebted to Drs. William G. Degenhardt, University of New Mexico, Herndon G. Dowling, New York Zoological Society, Charles H. Lowe, University of Arizona, and Richard G. Zweifel, American Museum of Natural History, for criticizing the manuscript. Dr. William E. Duellman permitted us to study specimens in the University of Kansas Museum of Natural History.