Produced by Chris Curnow, Simon Gardner, Joseph Cooper and the Online Distributed Proofreading Team at http://www.pgdp.net Transcriber's Notes Italic typeface is indicated by _underscores_. Bold typeface is indicated by =equals=. "Rijkmuseum van Natuurlijke Histoire" changed to "Rijksmuseum van Natuurlijke Historie" (Rijksmuseum van Natuurlijke Historie, Leiden) corrected typo period for comma (Erpétologie générale, vol. 7, p. 268) "Chipas" changed to "Chiapas" (Guatemalan highlands and probably highlands of Chiapas.) The style of the majority of citations in this paper are of the form "(year: page)". A small number of citations been ammended to include the space following the colon. * * * * * UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Vol. 10, No. 10, pp. 599-610, 1 pl., 1 fig. May 2, 1960 A Taxonomic Study of the Middle American Snake, Pituophis deppei BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1960 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Robert W. Wilson Volume 10, No. 10, pp. 599-610, 1 pl., 1 fig. Published May 2, 1960 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED IN THE STATE PRINTING PLANT TOPEKA, KANSAS 1960 28-2493 PLATE 45 [Illustration: FIG. 1. _Pituophis deppei deppei_ from Cumbres de Acultzingo, Veracruz, UMMZ 114596. Approx. 1/2 natural size.] [Illustration: FIG. 2. _Pituophis lineaticollis lineaticollis_ from Dos Aguas, Michoacán, UMMZ 119567. Approx. 1/3 natural size.] A Taxonomic Study of the Middle American Snake, Pituophis deppei BY WILLIAM E. DUELLMAN INTRODUCTION As a part of a study of the herpetofauna of the Mexican state of Michoacán an attempt was made to ascertain the interspecific and intraspecific relationships of the various populations of _Pituophis_ there. Field work in Michoacán revealed that two supposed subspecies of _Pituophis deppei_ were sympatric. This discovery led to the examination of all available (124) museum specimens of these snakes. I am grateful to the following persons who permitted me to examine specimens in their care: Charles M. Bogert, American Museum of Natural History (AMNH); Doris M. Cochran, United States National Museum (USNM); Norman Hartweg, University of Michigan Museum of Zoology (UMMZ); Robert F. Inger, Chicago Natural History Museum (CNHM); Arthur Loveridge, Museum of Comparative Zoology (MCZ); Hobart M. Smith, University of Illinois Museum of Natural History (UIMNH); and Edward H. Taylor, E. H. Taylor--H. M. Smith collection (EHT-HMS). Specimens in the accounts of the species are listed after the abbreviations of the institutions given in parentheses above. HISTORICAL REVIEW