Z 114596. Approx. 1/2 natural size.]

[Illustration: FIG. 2. _Pituophis lineaticollis lineaticollis_ from Dos
Aguas, Michoac['a]n, 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
Michoac['a]n an attempt was made to ascertain the interspecific and
intraspecific relationships of the various populations of _Pituophis_
there. Field work in Michoac['a]n 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

Dum['e]ril (1853: 453) described _Elaphis deppei_ from a specimen in the
Leiden Museum from "Mexico." This specimen, according to the type
description, has 233 ventrals and 67 caudals. In 1863 Jan described
_Pituophis deppei_ var. _pholidostictus_, also with "Mexico" as the type
locality. Subsequent authors (see synonymy of _P. deppei deppei_ in
Stull, 1940: 25) have treated _pholidostictus_ as a synonym of _deppei_.
Smith and Taylor (1950: 334) restricted the type localities of _deppei_
and _pholidostictus_ to San Juan Teotihuac['a]n, M['e]xico. Cope (1860:
369) described _Arizona jani_ on the basis of a specimen in the United
States National Museum from Buena Vista, Coahuila. Stull (1932: 2, 1940:
42), Smith (1944: 145) and Smith and Taylor (1945: 107) considered
_jani_ as a northern subspecies of _Pituophis deppei_. _Arizona
lineaticollis_ was described by Cope (1861: 300); the type, which
originally was in the Academy of Natural Sciences of Philadelphia and is
now lost, was said to have come from Jalapa, Veracruz. This locality
probably is in error. Smith (1943