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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

Duméril (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 Teotihuacán, México. 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: 460) placed _lineaticollis_ as a southern subspecies
of _deppei_. Schmidt and Shannon (1947: 79) described _Pituophis deppei
brevilineata_ on the basis of five specimens from Tancítaro, Michoacán,
and Stuart (1954: 172) described _Pituophis deppei gibsoni_ from seven
specimens from Departamento Chimaltenango, Guatemala. Thus, at present
five subspecies of _Pituophis deppei_ are recognized.


CHARACTERS STUDIED

Snakes currently assigned to _Pituophis deppei_ differ from other
members of the genus by possessing two instead of four prefrontal
plates. The subspecies of _P. deppei_ have been defined on characters of
coloration and scutellation.

_Scutellation._--The only scale characters utilized in the present study
are the numbers of ventrals and caudals. The number of ventrals varies
in the total sample from 210 to 246 (Table 1); usually the variation in
one locality is no more than 15. Number of caudals varies from 52 to 72.
There is slight sexual dimorphism in the number of ventrals and somewhat
greater differences in the number of caudals.

TABLE 1.--Variation in the Numbers of Ventrals and Caudals in Four
Subspecies of Pituophis.

==============================+====================+==================
SUBSPECIES                    |    Ventrals       |       Caudals
                              +---------+---------+---------+---------
                              | Range   |  Mean   |   Range |   Mean
------------------------------+---------+---------+---------+---------
_deppei deppei_               |         |         |         |
  34 ♂♂                       | 210-231 |   220.4 |   53-69 |   61.5
  16 ♀♀                       | 209-232 |   218.2 |   52-61 |   57.2
                              |         |         |         |
_deppei jani_                 |         |         |         |
  12 ♂♂                       | 215-235 |   225.1 |   56-68 |   62.6
   3 ♀♀                       | 228-231 |   229.0 |   52-60 |   56.0
                              |         |         |         |
_lineaticollis lineaticollis_ |         |         |         |
  13 ♂♂                       | 231-258 |   239.5 |   54-72 |   64.9
   9 ♀♀                       | 229-249 |   241.3 |   55-68 |   60.6
                              |         |         |         |
_lineaticollis gibsoni_       |         |         |         |
   2 ♂♂                       |     234 |   234.0 |   61-65 |   63.0
   4 ♀♀                       | 241-246 |   243.7 |   57-63 |   59.0
------------------------------+---------+---------+---------+---------



_Coloration._--The dorsal ground color is tan or straw; the dorsal
pattern consists basically of dark middorsal blotches and dark lateral
intercalary spots. Number of blotches, color of blotches posteriorly,
width of pale interspaces between anterior blotches, and color of
lateral intercalary spots vary considerably geographically. In some
populations (_lineaticollis_ and _gibsoni_) the anterior blotches are
divided medially forming either a pair of dark stripes on the anterior
part of the body or a series of paired spots. Details of coloration are
described in the following accounts.


ACCOUNTS OF THE SPECIES AND SUBSPECIES

[Illustration: FIG. 1. México and Guatemala showing the distribution of
the subspecies of _Pituophis deppei_ and _P. lineaticollis_.]

Study of _Pituophis deppei_ (_auctorum_) revealed the presence of
sympatric populations of two distinct species of _Pituophis_ differing
from each other in scutellation and coloration. The nomenclature
resulting from the required rearrangement necessitates the recognition
of 1) _deppei_ as a species, 2) _jani_ as a subspecies of _deppei_, 3)
_lineaticollis_ (with _brevilineata_ as a synonym) as a species distinct
from _deppei_, and 4) _gibsoni_ as a subspecies of _lineaticollis_.
Known geographic distributions of these named taxa are shown in Figure
1.


=Pituophis deppei deppei= Duméril

     _Elaphis deppei_ Duméril, Mem. Acad. Inst. France, vol. 23, p. 453,
     1853; Duméril and Bibron, Erpétologie générale, vol. 7, p. 268,
     February 25, 1854.

     _Pituophis deppei_, Jan, Elenco sistematico degli ofidi, p. 59,
     1863; Günther, Biologia Centrali-Americana, Reptilia, p. 124,
     February, 1894.

     _Elaphis pleurostictus_ Duméril, Mem. Acad. Inst. France, vol. 23,
     p. 453, 1853 [Type.--Museum d'Histoire Naturelle Paris, No. 6616;
     type locality--"Monte Video" (restricted to San Juan Teotihuacán,
     México, by Smith and Taylor, 1950: 334)].

     _Pituophis pleurostictus_, Jan, Elenco sistematico degli ofidi, p.
     59, 1863.

     _Pituophis deppei_, var. _pholidostictus_ Jan, Elenco sistematico
     degli ofidi, p. 59, 1863 [Type.--Zoologisches Museum Berlin, No.
     1738; type locality.--"Mexico" (restricted to San Juan Teotihuacán,
     México, by Smith and Taylor, 1950: 334)].

     _Pituophis deppei deppei_, Stull, Occas. Papers Mus. Zool. Univ.
     Michigan, no. 250, p. 1, October 12, 1932; Bull. U. S. Natl. Mus.
     175, p. 25, April 23, 1940; Smith and Taylor, U. S. Natl. Mus., no.
     187, p. 107, 1945.

_Type._--Rijksmuseum van Natuurlijke Histoire, Leiden, No. ???, obtained
by Ferdinand Deppe. The type locality was originally given as "Mexico";
this was restricted to San Juan Teotihuacán, state of México, by Smith
and Taylor (1950: 334).

_Diagnosis._--This subspecies is characterized by the presence of solid
body-blotches and lateral intercalary spots, dorsal interspaces less
than five scales in length, and the absence of paired stripes or rows of
blotches, on the anterior part of the body. There are 209 to 232
ventrals and 52 to 62 caudals. The body-blotches number 27 to 49. In
adults the anterior and posterior body-blotches are black; the lateral
intercalary spots are solid black. In many individuals black dashes
connect the adjacent corners of the dorsal body-blotches (Pl. 45, Fig.
1). In juveniles the anterior, dorsal body-blotches are black, whereas
those at the midbody and posteriorly are brown.

_Variation._--Geographically, scutellation varies only slightly.
Comparison of specimens from the northern part of the Mexican Plateau
(Chihuahua, Coahuila, and Durango--5 specimens), the central part of the
plateau (Aguascalientes, San Luis Potosí, and Zacatecas--13 specimens),
the southern part of the plateau (Guanajuato, Jalisco, México, and
Michoacán--18 specimens), and Puebla and southern Veracruz (12
specimens) shows the average number of ventrals for these samples to be,
respectively, 221.6, 216.7, 221.3, and 220.0. The average number of
dorsal body-blotches for the same samples are, respectively, 36.6,
37.7, 38.4, and 34.6. Only in the southernmost sample is there a
noticeable difference in the number of blotches.

The specimen from Párajo Verde, Veracruz, was considered to be an
intergrade between _P. deppei_ and _P. lineaticollis_ by Smith (1943:
461), who stated that, although the snake had 231 ventrals and dark
lateral streaks as does _deppei_, it had light-centered dorsal blotches
and stripes on the neck as does _lineaticollis_. This specimen (USNM
110892) has a high number of ventrals for _deppei_; one from Jalisco has
232, and one each from Guanajuato and Veracruz have 229. The blotches
posteriorly are lighter than those anteriorly and are slightly lighter
in the center than at the periphery. Two anterior blotches are divided
medially and narrowly connected by black streaks. Although these are
somewhat suggestive of the pattern of _lineaticollis_, they are more
nearly like that of _deppei_. Four other specimens from the same area
are typically _deppei_. There is some doubt as to the actual provenance
of the snake stated to have come from Párajo Verde, for, according to
Smith (1943: 460), the snake had been tied to a truck and dragged
halfway down the slopes of the Cumbres de Acultzingo, where he found it.
He surmised that it probably was dragged no farther than the settlement,
Párajo Verde, at the Cumbres de Acultzingo.

Fugler and Webb (1956: 171) commented on the uniformly brown dorsum of a
specimen (KU 39564) from 16 miles east and 18 miles north of Ocampo,
Coahuila. It has a higher number of ventrals (242) and caudals (88) than
is known for deppei. It is, without a doubt, a _Pituophis_. It is not
_Pituophis catenifer_, as attested to by the presence of only two
prefrontals. The high number of ventrals and caudals, together with the
uniform dark brown dorsum, provide a combination of characters
indicating that this specimen may represent an undescribed species in
the _deppei_ group of _Pituophis_.

_Distribution._--Southern Chihuahua and southern Coahuila southward on
the western and central parts of the Mexican Plateau to the Valley of
México and to southeastern Puebla and adjacent Veracruz.

_Specimens examined._--Total of 63, as follows: _Aguascalientes_: 16 km.
N of Aguascalientes, UIMNH 27149; 17 km. E of Aguascalientes, UIMNH
36222; 5 km. SW of Aguascalientes, KU 29495; Cavillito, UIMNH 28134; 11
km. N of Rincon de Romos, UIMNH 40359-60; 2 km. N of San Francisco de
los Romos, UIMNH 27569. _Chihuahua_: USNM 8321 (2 specimens);
Semachique, CNHM 11825. _Coahuila_: Castanuelas, MCZ 407. _Distrito
Federal_: Lago Xochimilco, UIMNH 18709; Pedregal, UMMZ 99790. _Durango_:
Coyotes, CNHM 1497; Hacienda Magdalena, USNM 46365; Llano Grande, UMMZ
113634. _Guanajuato_: USNM 16442; Acambaro, KU 45003; Irapuato, UIMNH
35055. _Jalisco_: Atemajac, USNM 46385; Guadalajara, USNM 24969; 5 km.
SE of Guadalajara, KU 29508; Jamay, AMNH 19848-9, 19851-2; 3 km. WNW of
Lagos de Moreno, KU 27727; 5 km. NW of Sayula, UMMZ 101933. _México_:
Atzocozlco, AMNH 19850; Chalco, USNM 110889; San Juan Teotihuacán,
EHT-HMS 5378, 5383, MCZ 16051. _Michoacán_: 6 km. E of Carapan, AMNH
69940; 3 km. W of Carapan, UMMZ 114598; 14 km. W of Morelia, UMMZ
104969; Tacambaro, USNM 46557; Tacícuaro, USNM 110888; 11 km. W of
Zacapu, UMMZ 104968. _Puebla_: Alseseca, UIMNH 36221; Atlixco, USNM
46433; Puebla, AMNH 19856; 30 km. N of Puebla, USNM 110887;
Tecamachalco, UMMZ 88688; 16 km. SSE of Tecamachalco, UMMZ 114597;
Tehuacan, UMMZ 88687; 22 km. N of Tehuacan, EHT-HMS 5377. _San Luis
Potosí_: USNM 46554; 26 km. SW of San Luis Potosí, UIMNH 28133.
_Veracruz_: 3 km. W of Acultzingo, KU 23978; Cumbres de Acultzingo,
UIMNH 36224, 36226, UMMZ 114596; Párajo Verde, USNM 110892; questionably
from Potrero Viejo, UMMZ 89358-9. _Zacatecas_: 16 km. E of Somberete,
UIMNH 27147; 1 km. SW of Tiburcio, KU 33599; 3 km. ESE of Troncoso, KU
29494; 10 km. W of Villa de Arriaga (San Luis Potosí), UIMNH 27151; 24
km. NW of Zacatecas, UIMNH 6393; 13 km. SE of Zacatecas, UIMNH 27148; 26
km. SE of Zacatecas, UIMNH 27568.


=Pituophis deppei jani= Cope

     _Arizona jani_ Cope, Proc. Acad. Nat. Sci. Philadelphia, p. 369,
     1860.

     _Pituophis deppei jani_, Stull, Occas. Papers Mus. Zool. Univ.
     Michigan, no. 250, p. 2, October 12, 1932, Bull. U. S. Natl. Mus.,
     no. 175, p. 42, April 23, 1940; Smith, Zool. Ser. Field Mus. Nat.
     Hist., vol. 29, p. 145, February 29, 1944; Smith and Taylor, Bull.
     U. S. Natl. Mus., no. 187, p. 107, 1940.

_Type._--United States National Museum, No. 1522, from Buena Vista,
Coahuila, obtained by Lieutenant Darius N. Couch.

_Diagnosis._--This subspecies is characterized by solid body-blotches
that are black anteriorly and brown posteriorly, anterior dorsal
interspaces six or more scales in length, and the absence of dark
stripes or rows of spots on the anterior part of the body. There are 215
to 235 ventrals, 52 to 68 caudals, and 21 to 31 dorsal body-blotches.
The position of the lateral intercalary spots and lateral streaks are
the same as in _deppei deppei_.

_Variation._--Throughout the range of this subspecies the posterior
body-blotches are brown and noticeably lighter than the anterior ones.
Juveniles are colored like adults. Specimens from the northern part of
the range (Nuevo León and Tamaulipas) have 21 to 28 (average 24.0)
dorsal body-blotches and 7 to 11 (average 8.9) scales in the interspace
between the first and second dorsal body-blotches, as compared with
specimens from the southern part of the range (Hidalgo, Queretaro, and
San Luis Potosí), which have 24 to 31 (average 27.7) dorsal
body-blotches and 6 to 10 (average 7.8) scales in the first interspace.
Likewise, there is a difference in the number of ventrals between the
northern and southern samples; those from the north have an average of
228.8 ventrals, and those from the south have 222.0. In all of these
characters the southern sample shows trends towards the southern
subspecies, _deppei_, which has fewer ventrals, fewer scales in the
first interspace, and more dorsal body-blotches.

_Distribution._--Eastern part of the Mexican Plateau and lower leeward
slopes of the Sierra Madre Oriental from Hidalgo and Queretaro northward
to southeastern Coahuila.

_Specimens examined._--Total of 28, as follows: _Coahuila_: Buena Vista,
USNM 1522; 50 km. W of La Rosa, EHT-HMS 5374. _Hidalgo_: Ixmiquilpan,
USNM 110890-1; 24 km. S of Ixmiquilpan, EHT-HMS 5373; Jacala, UMMZ
80937; 35 km. E of Pachuca, UMMZ 99552; 16 km. E of Tulancingo, KU
40357. _Nuevo León_: Ojo de Agua near Galeana, CNHM 33564-5.
_Queretaro_: Cadereyta, UMMZ 99791-3. _San Luis Potosí_: Charcas, UMMZ
77256-8; San Diego, UMMZ 77254-5; 24 km. NE of San Luis Potosí, UIMNH
18711; 30 km. NE of San Luis Potosí, UIMNH 27150, 28135. _Tamaulipas_:
Miquihuana, MCZ 19544-50.


=Pituophis lineaticollis lineaticollis= Cope, new combination

     _Arizona lineaticollis_ Cope, Proc. Acad. Nat. Sci. Philadelphia,
     p. 300, 1861.

     _Pituophis lineaticollis_, Stull, Occas. Papers Mus. Zool. Univ.
     Michigan, no. 250, p. 2, October 12, 1932, Bull. U. S. Natl. Mus.,
     no. 175, p. 47, April 23, 1940.

     _Pituophis deppei lineaticollis_, Smith, Proc. U. S. Natl. Mus.,
     vol. 93, p. 460, 1943; Smith and Taylor, Bull. U. S. Natl. Mus.,
     no. 187, p. 108, 1945.

     _Pituophis deppei brevilineata_ Schmidt and Shannon,
     Fieldiana-Zool., vol. 31, p. 79, February 20, 1947.

_Type._--No type specimen is known. Cope (1861: 300 and 1887: 72) stated
that the specimen was from the southern Mexican Plateau and that it was
collected by Carlos Sartorius. Smith and Taylor (1945: 108 and 1950:
348) gave the type locality as Jalapa, Veracruz. Although this locality
was the source of many specimens sent to the United States by Sartorius,
it is not within the known range of _lineaticollis_, and therefore
cannot appropriately be thought of as the type locality. In the absence
of a type specimen and a justifiable type locality, I hereby designate
as a neotype, University of Michigan Museum of Zoology, No. 114668. This
specimen was collected 24 kilometers northwest of Ciudad Oaxaca, Oaxaca,
on February 29, 1956, by William E. Duellman. It is an adult female
having 229 ventrals, 67 caudals, and long black neck-stripes followed
posteriorly by 23 light-centered dorsal body-blotches.

_Diagnosis._--This subspecies is characterized by the presence of
continuous dark paravertebral stripes on the anterior part of the body,
and light-centered dorsal body-blotches and lateral intercalary spots
(Pl. 45, Fig. 2). There are 229 to 258 ventrals, 54 to 72 caudals, and
23 to 45 dorsal body-blotches posterior to the neck-stripes. The young
are colored like the adults.

_Variation._--Specimens from the southern part of the range in Oaxaca
have 229 to 245 ventrals (average 238.3); to the north on the Mexican
Plateau in the state of Michoacán seven specimens have 231 to 243
(average 237.1) ventrals. In the relatively isolated mountain ranges of
the Sierra del Sur in Guerrero and the Sierra de Coalcomán in southern
Michoacán the ranges of variation and average numbers of ventrals are,
respectively, 234 to 258 (245.8) and 236 to 246 (242.2). The longest
neck-stripes are found in specimens from Oaxaca and Guerrero;
nevertheless, some specimens from the Mexican Plateau in Michoacán and
three of the four specimens from the Sierra de Coalcomán have
neck-stripes equally long. One specimen from 40 kilometers north of
Ciudad México and several from the vicinity of Tancítaro, Michoacán,
have rather shorter neck-stripes. One specimen from Dos Aguas,
Michoacán, has the neck-stripes partially fragmented into rows of spots
as in _gibsoni_.

On the basis of specimens from Tancítaro, Michoacán, Schmidt and Shannon
(1947: 79) described the subspecies _brevilineata_, which they diagnosed
as differing from _lineaticollis_ in having fewer ventrals and shorter
neck-stripes. The present data suggest that the characters used to
diagnose the subspecies are variable not only in Michoacán, but
throughout the range of the species. Consequently, _Pituophis (deppei)
brevilineata_ Schmidt and Shannon (1947) is placed in the synonymy of
_Pituophis lineaticollis lineaticollis_ Cope (1861).

_Distribution._--The southern part of the Mexican Plateau in the states
of Michoacán, México, and Morelos, the Sierra de Coalcomán in southern
Michoacán, and the Sierra del Sur in Guerrero and Oaxaca.

_Specimens examined._--Total of 25, as follows: _Guerrero_: Acahuizotla,
USNM 46537; Chilpancingo, CNHM 38356-9, UIMNH 35000, UMMZ 85724-5;
Omiltemi, USNM 46462. _México_: 40 km. N of Ciudad México, UIMNH 36223.
_Michoacán_: Acuaro de las Lleguas, UMMZ 112565; Dos Aguas, UMMZ 118786,
119567-8; 40 km. E of Morelia, UMMZ 101932; Tancítaro, CNHM 37126,
39069-72. _Morelos_: 1 km. W of Tepoztlán, UMMZ 101931; Tres Cumbres,
UIMNH 35001. _Oaxaca_: 25 km. N of El Soledad, UIMNH 6210; 24 km. NW of
Oaxaca, UMMZ 114668; San Pedro Quiechapa, USNM 110893.


=Pituophis lineaticollis gibsoni= Stuart, new combination

     _Pituophis deppei gibsoni_ Stuart, Proc. Biol. Soc. Washington,
     vol. 67, p. 172, August 5, 1954.

_Type._--University of Michigan Museum of Zoology No. 107060, obtained
by Colvin Gibson. Type locality: Yepocapa, Chimaltenango, Guatemala.

_Diagnosis._--This race is characterized by paired, elongated,
pale-centered, paravertebral spots on the anterior part of the body.
Posterior to the paired spots are 22 to 27 dorsal body-blotches; these
and the lateral intercalary spots have pale centers. There are 234 to
246 ventrals and 57 to 65 caudals.

_Variation._--The few specimens that are available from a small
geographic area do not permit a discussion of geographic variation at
this time. All of the specimens have the paired paravertebral spots and
blotches with light centers. In this respect the population of
_lineaticollis_ east of the Isthmus of Tehuantepec is noticeably
different from the nominal subspecies in the Mexican highlands. Smith
and Taylor (1945: 108) listed a specimen from San Cristobal, Chiapas. I
have not seen this specimen and so do not know to which subspecies it
belongs. On geographical grounds it probably is _gibsoni_.

_Distribution._--Guatemalan highlands and probably highlands of Chiapas.
Aside from the specimens examined, two others are known--one from Volcán
Agua, Sacatepequez (Slevin, 1939: 400), and one from Dueñas,
Sacatepequez (Boulenger, 1894: 65); these localities are not shown in
figure 1.

_Specimens examined._--Eight, as follows: Guatemala: _Chimaltenango_:
Chichavac, CNHM 1927; Finca El Tesoro, 3 km. SE of Acatenango, UMMZ
107062-3; Finca Recreo, 4.5 km. SW of Yepocapa, UMMZ 107381; Río Los
Positos, 5.5 km. NE of Yepocapa, UMMZ 107061; Río Sobolopop, 8 km. W of
Patzún, UMMZ 107064; Yepocapa, UMMZ 107060. _El Quiche_: Nebaj, UMMZ
89202.




LITERATURE CITED


BOULENGER, G. A.

     1894. Catalogue of the snakes in the British Museum (Natural
     History). London, 2:xi + 382 pp., pls. 1-20.

COPE, E. D.

     1860. Descriptions of reptiles from tropical America and Asia.
     Proc. Acad. Nat. Sci. Philadelphia, 1860:368-374.

     1861. Contributions to the ophiology of Lower California, Mexico,
     and Central America. Proc. Acad. Nat. Sci. Philadelphia,
     1861:292-306.

     1887. Catalogue of the batrachians and reptiles of Central America
     and Mexico. Bull. U. S. Natl. Mus., 32: 1-98.

DUMÉRIL, A. M. C.

     1853. Prodrome général de la classification des serpents. Mem.
     Acad. Sci. Inst. France, 23:399-536, 2 pls.

DUMÉRIL, A. M. C., and BIBRON, G.

     1854. Erpétologie générale, ou histoire naturelle des reptiles.
     Paris, 7 (pt. 1): xvi + 780 pp.

FUGLER, C. M., and WEBB, R. G.

     1956. Distributional notes on some reptiles and amphibians from
     southern and central Coahuila. Herpetologica, 12:167-171.

GÜNTHER, A.

     1885-1902. Biologia Centrali-Americana. Reptilia and Batrachia.
     London, xx + 326 pp., pls. 1-76.

JAN, G.

     1863. Elenco sistematico degli ofidi. Milan, 143 pp.

SCHMIDT, K. P., and SHANNON, F. A.

     1947. Notes on amphibians and reptiles of Michoacan, Mexico.
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_Transmitted February 2, 1960._

28-2493