Chapter V: Part 5

Three males and five females from the Mexican Plateau and the Cordillera Volcanica have respectively 140-144 (141.7) and 143-151 (146.0) ventrals and 39-41 (40.0) and 29-35 (33.2) caudals. All have dorsal scales in 15 rows, 1 postocular, no anterior temporal, and a relatively small triangular supraocular. The specimen from Coalcoman (UMMZ 104698) was referred to _Geophis nasalis_ by Peters (1954:22). This specimen is abnormal in several characters; in five places there is a fusion and separation of the vertebral and paravertebral scale rows, producing a change from 17 to 15 rows of dorsal scales. Fusion of the three rows takes place at the level of the 8th, 41st, 47th, 54th, and 65th ventrals. Furthermore, there is a small secondary postocular on each side of the head. In other characters the specimen is like _G. petersi_; the resemblances to that species are greater than to _G. nasalis_, which has been recorded from Guatemala and southern Chiapas.

~Geophis tarascae~ Hartweg

_Geophis tarascae_ Hartweg, Occ. Pap. Mus. Zool. Univ.
Michigan, 601:1, May 4, 1959.--Uruapan, Michoacan, Mexico.

Uruapan (3).

A female of this species was collected in the Parque Nacional at the north edge of Uruapan in 1899, and a male was taken there in 1947; these specimens were used by Hartweg in his description of the species. Floyd L. Downs obtained another specimen in the Parque Nacional on July 19, 1960. It has 164 ventrals and 46 caudals; in life, the ground color of the neck was brown with a purplish tint; the dorsal markings were black; the chin was a cream-color, and the belly was white. This specimen is distinguished from those of all other species of _Geophis_ in Michoacan in that it has dark irregular cross-bars on the dorsum and a row of dark spots on the venter.

~Hypsiglena torquata ochrorhyncha~ Cope

_Hypsiglena ochrorhyncha_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 12:246, November 15, 1860.--Cape San Lucas,
Baja California, Mexico.

_Hypsiglena torquata ochrorhyncha_, Bogert and Oliver, Bull.
Amer. Mus. Nat. Hist., 83:378, March 30, 1945.

Tupataro.

The systematic status of the geographic variants of _Hypsiglena_ in Mexico and southwestern United States has been commented on by several authors. Tanner (1944) considered _H. torquata_ and _H. ochrorhyncha_ to be distinct species; Bogert and Oliver (1945:379) and Duellman (1957b:238) presented evidence indicating that _H. torquata_ and _H. ochrorhyncha_ intergrade in Sinaloa and southern Sonora. In _Hypsiglena_ the scutellation, including the numbers of labials, dorsals, ventrals, and caudals, seem to vary in a clinal manner. Nevertheless, these snakes can be divided into two distinct populations on the basis of the nuchal color pattern, consisting of an _ochrorhyncha_-type (a broad dark nape-band, the lateral edges of which extend anteriorly and fuse with a postorbital stripe, and a narrow nape stripe extending from the posteromedian edges of the parietals to the dark nape band) and a _torquata_-type (a somewhat narrower dark nape-band bordered anteriorly by a pale nuchal area, and no dark nape stripe). Snakes having the _ochrorhyncha_-type of nuchal pattern are found on the Mexican Plateau from Michoacan northward into the desert regions of Sonora and the southwestern United States. Snakes having the _torquata_-type of pattern are found on the coastal lowlands and adjacent slopes of the Sierra Madre Occidental from southern Sinaloa to Colima and thence inland in the Balsas-Tepalcatepec Basin to Morelos and Guerrero. An exception is _Hypsiglena torquata dunklei_ from Forlon and San Fernando, Tamaulipas; it has the _torquata_-type of nuchal pattern. The distributional picture is somewhat complicated because some individuals having the _torquata_-type of nuchal pattern also have a faint nape stripe. If these are taken as exceptions, the general picture of distribution in Mexico is _H. t. torquata_ on the Pacific lowlands from Sinaloa southward to the Balsas Basin and _H. t. ochrorhyncha_ on the Mexican Plateau.

Smith (1943:433) resurrected _Hypsiglena jani_ Duges for the snakes of the _ochrorhyncha_-type on the southern part of the Mexican Plateau. He stated that the southern specimens differed from northern ones in having a nuchal spot 9 or 10 scales in length, as compared with a spot 2 to 6 scales in length in northern specimens. A cursory examination of specimens from the areas between Arizona and Michoacan showed that there is a gradual increase in the size of the spot from north to south. If no other characters can be found to distinguish the populations, they should be considered as a single subspecies.

_Hypsiglena affinis_ differs from _H. torquata_ in possessing 19 instead of 21 rows of dorsal scales. Additional material is needed from the western slopes of Jalisco and the Barrancas in Zacatecas and Durango, before definite allocation of _affinis_ can be made.

Bogert and Oliver (1945:379) discussed the status of certain named populations in Baja California and concluded that only one species occurs there, and that the species probably is conspecific with _H. torquata_. A careful review of the genus _Hypsiglena_ might show that there is only one species.

The one specimen from Michoacan (USNM 46513) is from an elevation of about 2300 meters near the southern edge of the Mexican Plateau.

~Hypsiglena torquata torquata~ (Guenther)

_Leptodeira torquata_ Guenther, Ann. Mag. Nat. Hist., ser. 3,
5:170.--Laguna Island, Nicaragua (in error).

_Hypsiglena torquata torquata_, Taylor, Univ. Kansas Sci.
Bull., 25:371, July 10, 1939.

Apatzingan; Capirio; Cofradia.

Specimens from the three mentioned localities have the dark nuchal spot bordered anteriorly by a pale blotch. In life the specimen from Capirio (UMMZ 114424) had rich reddish brown dorsal spots; the dorsal ground color was grayish white above and somewhat more gray laterally. The pale nuchal area was a cream-color, and the iris was grayish red.

All of the specimens were found in the arid scrub forest in the Tepalcatepec Valley at elevations between 200 and 350 meters.

~Imantodes gemmistratus gracillimus~ (Guenther)

_Dipsas gracillima_ Guenther, Biol. Centrali-Americana,
Rept., p. 177, July, 1895.--southern Mexico. Type locality
restricted to Acapulco, Guerrero, Mexico, by Smith and
Taylor (1950a:331).

_Imantodes gemmistratus gracillimus_, Zweifel, Amer. Mus.
Novitates, 1961:12, September 16, 1959.

La Orilla.

The specimen from La Orilla was reported by Peters (1954:23) as _Imantodes gemmistratus oliveri_; Zweifel (1959c) showed that _I. g. oliveri_ did not range west of Tehuantepec and that the snakes inhabiting the coastal lowlands of Guerrero, Michoacan, and Colima were assignable to the subspecies _gracillimus_. It may be assumed that this subspecies ranges throughout the coastal lowlands and foothills of the Sierra de Coalcoman.

~Imantodes gemmistratus latistratus~ (Cope)

_Dipsas gemmistrata latistrata_ Cope, Bull. U. S. Natl.
Mus., 32:68, 1887.--Southern Jalisco. Type locality
restricted to Guadalajara, Jalisco, Mexico, by Smith and
Taylor (1950a:334).

_Imantodes gemmistratus latistratus_, Zweifel, Amer. Mus.
Novitates, 1961:3, September 16, 1959.

El Sabino.

The one specimen from Michoacan was collected near the upper limits of the scrub forest on the slopes of the Cordillera Volcanica. Zweifel (1959c:10) stated that in certain aspects of coloration this specimen was like _I. gemmistratus gracillimus_, but in scutellation and other features of coloration it was like _I. g. latistratus_. There are too few specimens of this species to define the ranges of the various subspecies with any degree of accuracy, but from the limited number of specimens available, it seems that _I. gemmistratus gracillimus_ occurs on the Pacific lowlands from Guerrero northward to Colima. Northward on the Pacific lowlands from Colima to Sinaloa and in the Balsas-Tepalcatepec Basin is found _I. gemmistratus latistratus_.

~Lampropeltis doliata~ (Linnaeus)

_Coluber doliatus_ Linnaeus, Systema naturae, ed. 12, 1:379,
1766.--Charleston, South Carolina.

_Lampropeltis doliata_, Klauber, Copeia, No. 1:11, April 15,
1948.

Coalcoman (3); El Sabino; 24 km. W of Morelia; Rio Nexpa;
Uruapan.

The few specimens of this species from Michoacan show a wide range of variation; furthermore, the present systematic status of the subspecies of _Lampropeltis doliata_ portrays an incongruous pattern of distribution. Specimens from the Sierra de Coalcoman have relatively narrow red bands that are not interrupted dorsally by extensions of the black rings; the scales in the red bands have black tips. The specimen from El Sabino (EHT-HMS 5253) and the one from the Rio Nexpa on the coast (USNM 31491) have broader red bands; the scales in the red bands do not have black tips. A specimen from 24 kilometers west of Morelia (UIMNH 17782) and one from Uruapan (UMMZ 121508) have the red bands interrupted dorsally by extensions from the black rings.

Specimens from the Sierra de Coalcoman were referred to _L. doliata blanchardi_ by Peters (1954:24), who noted that in some characters these snakes were like _L. d. nelsoni_ and in others like _L. d. polyzona_. The individual from El Sabino was referred to _L. d. nelsoni_ by Taylor (1940c:465); the one from 24 kilometers west of Morelia was referred to _L. d. arcifera_ by Smith (1942c:198). If these assignments are correct, three subspecies of _Lampropeltis doliata_ occur in Michoacan: _blanchardi_ in the Sierra de Coalcoman, _nelsoni_ on the coast and in the Tepalcatepec Valley, and _arcifera_ on the Mexican Plateau and in the Cordillera Volcanica. Such a distribution is plausible, but the few specimens and our general lack of knowledge of the variation and relationships of the different populations do not permit a definite assignment at this time.

~Lampropeltis ruthveni~ Blanchard

_Lampropeltis ruthveni_ Blanchard, Occ. Pap. Mus. Zool.
Univ. Michigan, 81:8, April 28, 1920.--Patzcuaro, Michoacan,
Mexico.

Morelia; Patzcuaro; Tacicuaro.

At the present time this species is known definitely from only three localities on the Mexican Plateau in Michoacan. An incomplete skin from El Sabino (EHT-HMS 5438) was referred to this species by Taylor (1940c:465); the specimen cannot be found, so verification of the identification cannot be made at this time.

~Leptodeira latifasciata~ (Guenther)

_Hypsiglena latifasciata_ Guenther, Biologia
Centrali-Americana, Reptilia, p. 138, October,
1894.--Southern Mexico. Type locality restricted to
Huajintlan, Morelos, Mexico, by Smith and Taylor
(1950a:331).

_Leptodeira latifasciata_, Dunn, Proc. Natl. Acad. Sci.,
22:696, December, 1936.

Apatzingan; El Sabino; La Playa; 32 km. E of Nueva Italia.

This nocturnal snake apparently ranges throughout the arid Balsas-Tepalcatepec Valley to elevations of about 1050 meters. It has been collected only in the arid scrub forest. Aside from the specimens listed by Duellman (1958a:93), there is one (UMMZ 120223) having eight body blotches, a body length of 510 mm. and a tail length of 103 mm.

~Leptodeira maculata~ (Hallowell)

_Megalops maculatus_ Hallowell, Proc. Acad. Nat. Sci.
Philadelphia, 13:488, March 31, 1862.--"Tahiti." Type
locality restricted to Manzanillo, Colima, Mexico, by
Duellman (1958a:54).

_Leptodeira maculata_, Duellman, Bull. Amer. Mus. Nat.
Hist., 114:53, February 24, 1958.

Aguililla (2); Apatzingan (24); Arteaga (2); Capirio (3);
Charapendo (2); Coahuayana (3); Cofradia; Cuatro Caminos; La
Placita (3); Lombardia (69); Nueva Italia (29); Pomaro; Rio
Marquez, 10 km. S of Lombardia (2); Salitre de Estopila;
Tafetan (2); Volcan Jorullo.

This snake is abundant in the arid Tepalcatepec Valley; most of the specimens have been collected in arid scrub forest at elevations of less than 500 meters. With the onset of the rains in late June and early July, large numbers of these snakes can be found around temporary pools, where they feed on small frogs and toads. In the dry season few individuals were found, and all of those were beneath cover. Specimens from the coast have more body-blotches than do those from the Tepalcatepec Valley (Duellman, 1958a:56); otherwise the snakes show little variation.

~Leptodeira splendida bressoni~ Taylor

_Leptodeira bressoni_ Taylor, Univ. Kansas Sci. Bull.,
25:321, July 10, 1939.--Hacienda El Sabino, Michoacan,
Mexico.

_Leptodeira splendida bressoni_, Duellman, Bull. Amer. Mus.
Nat. Hist., 114:84, February 24, 1958.

Coalcoman (3); El Sabino (3); Uruapan (5).

The range of _Leptodeira splendida bressoni_ apparently does not overlap that of _Leptodeira maculata_; the latter is restricted to the lower reaches of the arid scrub forest, whereas _L. s. bressoni_ inhabits the upper limits of the arid scrub forest and the lower part of the pine-oak forest. Specimens have been collected between 950 and 1630 meters on the slopes of the Cordillera Volcanica and at 950 meters in the Sierra de Coalcoman. At Uruapan individuals were found beneath rocks along a stream and in a stone fence. _Leptodeira duellmani_, which was described from Coalcoman by Peters (1954:25), is an aberrant individual of _L. s. bressoni_ (Duellman, 1958a:56).

~Leptophis diplotropis~ (Guenther)

_Ahaetulla diplotropis_ Guenther, Ann. Mag. Nat. Hist., ser.
4, 9:25, 1872.--Tehuantepec, Oaxaca, Mexico.

_Leptophis diplotropis_, Bocourt, Mission scientifique au
Mexique et dans l'Amerique Centrale, Reptiles, livr. 15:835,
1897.

Between Aguililla and Dos Aguas; Arteaga; Coalcoman; El
Diezmo; El Sabino (5); La Playa; Ocorla.

Most specimens of this species have been collected in tropical semi-deciduous forest at elevations of less than 1000 meters. In the Sierra de Coalcoman one was taken in pine-oak forest at an elevation of 1700 meters near Ocorla; another was found in broad-leafed forest between Aguililla and Dos Aguas at an elevation of 1600 meters. Most individuals have been seen in trees or bushes. The absence of broad-leafed forest in the Tepalcatepec Valley probably accounts for the absence of this snake in that area.

~Manolepis putnami~ (Jan)

_Dromicus putnami_ Jan, Elenco sistematico degli Ofidi, p.
67, 1863.--San Blas, Nayarit, Mexico.

_Manolepsis putnami_, Smith and Taylor, Bull. U. S. Natl.
Mus., 187:92, October 5, 1945.

La Placita (3); Maquili; Ostula.

In Michoacan the species has been found only in tropical semi-deciduous forest on the lower slopes of the Sierra de Coalcoman. From the observations made by Peters (1954:28), this snake is diurnal and feeds on teiid lizards.

~Masticophis striolatus striolatus~ Mertens

_Coluber striolatus_ Mertens, Zoologica (Stuttgart), 32:190,
1934.--Substitute name for _Coluber lineatus_ Bocourt, a
secondary homonym of _Coluber lineatus_ Linnaeus = _Lygophis
lineatus_. Type locality restricted to Presidio de Mazatlan,
Sinaloa, Mexico, by Smith and Taylor (1950a:343).

_Masticophis striolatus striolatus_, Zweifel and Norris,
Amer. Midl. Nat., 54:242, July, 1955.

Apatzingan (4); Arteaga; Coalcoman (3); El Sabino;
Jiquilpan; La Palma; La Playa (3); Lombardia; Nueva Italia;
Rio Cachan; Santa Ana; Uruapan (2); Volcan Jorullo;
Ziracuaretiro.

This large diurnal species inhabits open scrub forest and cultivated terrain from sea level to about 1650 meters. On the Mexican Plateau it is known from the area around Lago de Chapala, to which it possibly gained access through the valleys in the headwaters of the Tepalcatepec drainage. Specimens from southern Michoacan have been reported previously by Peters (1954:28) and Duellman (1954b:16) as _Masticophis flagellum lineatus_.

~Masticophis taeniatus australis~ Smith

_Masticophis taeniatus australis_ Smith, Jour. Washington
Acad. Sci., 31:390, September 11, 1941.--Guanajuato,
Guanajuato, Mexico.

Tacicuaro (2); Zamora.

This species reaches the southern limit of its distribution in the state of Michoacan. The limited ecological data available suggest that the species inhabits the open mesquite grassland of the Mexican Plateau.

~Oxybelis aeneus auratus~ (Bell)

_Dryinus auratus_ Bell, Zool. Jour., 2:324, 1825.--Mexico.
Type locality restricted to Tehuantepec, Oaxaca, Mexico, by
Smith and Taylor (1950a:340).

_Oxybelis aeneus auratus_, Bogert and Oliver, Bull. Amer.
Mus. Nat. Hist., 83:381, March 30, 1945.

Coahuayana; El Sabino (4); between Las Tecatas and Las
Higuertas; between Los Pozos and La Cienega; Playa Azul;
Pomaro (2); between Pomaro and Maruata (2); Punto San Telmo;
Rio Tizupan.

On the basis of the number of specimens seen and collected on the seaward slopes of the Sierra de Coalcoman, this is a common snake there. Most specimens were collected in tropical semi-deciduous forest; others were collected in oak forest to an elevation of 1700 meters. Apparently _Oxybelis_ does not inhabit the lower parts of the Tepalcatepec Valley; the only specimens from the inland area are four from El Sabino, which is situated at about 900 meters on the slopes of the Cordillera Volcanica. One individual was seen in gallery forest near Limoncito at an elevation of 730 meters on the northern slopes of the Sierra de Coalcoman.

~Pituophis deppei deppei~ (Dumeril)

_Elaphis deppei_ Dumeril, Mem. Acad. Inst. France, 23:453,
1835.--Mexico. Type locality restricted to San Juan
Teotihuacan, Mexico, Mexico, by Smith and Taylor
(1950a:334).

_Pituophis deppei deppei_, Stull, Occ. Pap. Mus. Zool. Univ.
Michigan, 250:1, October 12, 1932.

Carapan (2); Morelia; Tacambaro; Tacicuaro; Zacapu.

Duellman (1960b) showed that the widespread species _Pituophis deppei_ was composite and that the "lined subspecies" actually represented another species, _Pituophis lineaticollis_. _Pituophis deppei_ occurs only on the Mexican Plateau; in Michoacan it inhabits mesquite grassland and oak-bunch grass associations between 1900 and 2200 meters.

~Pituophis lineaticollis lineaticollis~ (Cope)

_Arizona lineaticollis_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 13:300, December 28, 1861.--Southern Mexican
Plateau. Type locality restricted to 24 kilometers northwest
of Oaxaca, Oaxaca, Mexico, by Duellman (1960b:607).

_Pituophis lineaticollis lineaticollis_, Duellman, Univ.
Kansas Publ. Mus. Nat. Hist., 10:607, May 2, 1960.

Acuaro de las Lleguas; Dos Aguas (3); Morelia; Tancitaro
(5).

This species reaches the northern limits of its range in the Sierra de Coalcoman and on the Mexican Plateau in Michoacan. On the plateau it has been collected in mesquite grassland at elevations between 1500 and 2000 meters. In the Sierra de Coalcoman individuals were found in open pine-oak forest at 2100 meters elevation and in a meadow surrounded by pine-oak forest at 2300 meters.

~Pseudoficimia frontalis~ (Cope)

_Toluca frontalis_ Cope, Proc. Acad. Nat. Sci. Philadelphia,
16:167, September 30, 1864.--Colima, Colima, Mexico.

_Pseudoficimia frontalis_, Guenther, Biologia
Centrali-Americana, Reptilia, p. 96, May, 1893.

Apatzingan; Coalcoman (6); El Sabino (2).

Most specimens were found beneath rocks in grassy areas near the upper limits of the arid scrub forest, both in the Sierra de Coalcoman and on the southern slopes of the Cordillera Volcanica; all are from elevations of less than 1100 meters. One specimen was found on a road at night near Apatzingan. This species has been found in similar habitats near Huajintlan, Guerrero, and in arid scrub forest at lower elevations in Colima. It is unknown from the coast of Michoacan.

~Pseudoficimia pulcherrima~ Taylor and Smith

_Pseudoficimia pulcherrima_ Taylor and Smith, Univ. Kansas
Sci. Bull., 28:246, May 15, 1942.--Huajintlan, Guerrero,
Mexico.

Apatzingan.

This specimen (CNHM 39208) was reported by Schmidt and Shannon (1947:81); they stated that it was a paratype of _P. pulcherrima_. However, Taylor and Smith (1942a:246) did not mention the specimen; aside from the type (EHT-HMS 5497), the only other specimen they designated as belonging to the type series was UMMZ 85711 from Chilpancingo, Guerrero.

The taxonomic validity of _Pseudoficimia pulcherrima_ remains doubtful, for only minor characters distinguish it from _P. frontalis_. Furthermore, all known specimens of _P. pulcherrima_ are from within the geographic range of _P. frontalis_.

~Rhadinaea hesperia hesperia~ Bailey

_Rhadinaea hesperia_ Bailey, Occ. Pap. Mus. Zool. Univ.
Michigan, 412:8, May 6, 1940.--Omilteme and Sierra de Burro,
Guerrero. Type locality restricted to Omilteme, Guerrero,
Mexico, by Smith and Taylor (1950a:332).

_Rhadinaea hesperia hesperia_, Smith, Proc. Biol. Soc.
Washington, 55:185, December 31, 1942.

Arteaga (3); Coalcoman; El Sabino (2); Uruapan; Volcan
Jorullo (2).

One specimen from Volcan Jorullo (UMMZ 104494), three from Arteaga (UMMZ 119281), and one from Uruapan (UMMZ 92342) are typical of the subspecies _R. h. hesperia_ in possessing a lateral cream-colored line on the sixth and parts of the fifth and seventh dorsal scale rows and in lacking a dark line on the second scale row. The specimens from El Sabino (EHT-HMS 5441 and UIMNH 18933) and one from Coalcoman (UMMZ 104502) have the cream-colored line on the sixth and adjacent parts of the fifth and seventh scale rows and have a dark line on the second scale row. Another individual from Volcan Jorullo (UMMZ 104682) has cream-colored lines like the others, but it possesses two lateral dark lines, one on the second scale row, and one on the third.

Smith (1942d:186) diagnosed _Rhadinaea hesperia hesperioides_ as differing from the nominal subspecies in having the cream-colored line on the fourth and fifth scale rows and in possessing a dark line on the second scale row. The specimens seen all have the lateral cream-colored line centered on the sixth scale row, as is characteristic of _R. h. hesperia_. Although many of the specimens also possess a dark line on the second scale row, these specimens are here assigned to _R. h. hesperia_. Additional specimens are necessary to define accurately the subspecies and their ranges. Peters (1954:29) assigned the specimens from Coalcoman to _R. h. hesperioides_.

In life the specimens from Arteaga had bright cream-colored temporal stripes and dorsolateral stripes on the anterior part of the body. The chin and anterior one-sixth of the belly was white; posteriorly the venter was bright orange-red.

In Michoacan this snake has been found in tropical semi-deciduous forest, arid scrub forest, and pine-oak forest at elevations from 850 to 1500 meters.

~Rhadinaea laureata~ (Guenther)

_Dromicus laureatus_ Guenther, Ann. Mag. Nat. Hist., ser. 4,
1:419, 1868.--Mexico City.

_Rhadinaea laureata_, Boulenger, Catalogue Snakes... British
Museum, 2, p. 179, September 23, 1894.

Capacuaro; Carapan (8); Cheran (3); Paracho (2); Patzcuaro;
Tancitaro (10).

This snake is abundant in the Cordillera Volcanica, but it is unknown in the mountains to the northeast of Morelia or in the Sierra de Coalcoman. Most specimens were found beneath volcanic rocks imbedded in the ashy soil in pine forest between 1800 and 2300 meters.

~Rhadinaea taeniata~ (Peters)

_Dromicus taeniatus_ Peters, Monats. Akad. Wiss. Berlin, p.
275, 1863.--Mexico.

_Rhadinaea taeniata_, Bailey, Occ. Pap. Mus. Zool. Univ.
Michigan, 412:14, May 6, 1940.

Tancitaro (2).

This species, which is known only from a small region in the mountains of Jalisco and central Michoacan, is represented by two specimens (CNHM 37130 and 39030) collected at Tancitaro (see Schmidt and Shannon, 1947:80).

~Salvadora bairdi~ Jan

_Salvadora Bairdii_ Jan. Icon. gener. ophid., livr. 2, pl.
3, fig. 2, 1860.--Mexico. Type locality restricted to
Acambaro, Guanajuato, Mexico, by Smith and Taylor
(1950a:330).

Barranca Seca; Carapan; Cerro San Andres; Cojumatlan (2);
Jiquilpan; Morelia; Patzcuaro (4); Quiroga; Sahuayo (2);
Tacicuaro (12); Tancitaro (56); Uruapan (2); Zacapu (2);
between Zitacuaro and Tuxpan (3).

This species is abundant on the Mexican plateau, where it inhabits the more grassy areas in the mesquite grassland and cutover land in the pine forests from 1550 to 2500 meters. Davis and Dixon (1957:21) described a specimen from Zacapu as having two dark paravertebral stripes diverging on the temporals and extending through the eye onto the loreal, a characteristic of _Salvadora lineata_. On the basis of this specimen, Davis and Dixon suggested that _Salvadora bairdi_ and _S. lineata_ were subspecifically related. The examination of the large number of specimens from Michoacan has revealed this kind of coloration in only one other specimen, an individual from Tacicuaro, in which the stripes diverge, but do not extend through the eye onto the loreal. Data on scutellation for the large series from Tancitaro were given by Schmidt and Shannon (1947:78), and for the series from Tacicuaro by Smith (1943:466).

~Salvadora mexicana~ (Dumeril, Bibron, and Dumeril)

_Zamenis mexicanus_ Dumeril, Bibron, and Dumeril,
Erpetologie generale, 7 (pt. 1), p. 695, 1854.--Cape
Corrientes, Jalisco, Mexico.

_Salvadora mexicana_ Guenther, Ann. Mag. Nat. Hist., ser. 3,
12:349, 1863.

Apatzingan (12); Capirio (2); El Sabino (5); Huetamo; La
Placita; La Playa (4); Lombardia; Nueva Italia; Ojos de Agua
de San Telmo; Oropeo; Rio Cancita, 14 km. E of Apatzingan;
Santa Ana.

This is one of the most abundant snakes in the arid lowlands of the Tepalcatepec Valley; observations indicate that it probably is equally abundant on the coastal lowlands. Near Apatzingan as many as five of these snakes have been seen in one-half hour. The snakes seem to be equally abundant and active in the dry season and in the rainy season. Most individuals were seen on the ground, but two were found in low trees. On several occasions _Salvadora mexicana_ was observed in pursuit of lizards on the ground. Captured individuals regurgitated _Cnemidophorus costatus zweifeli_, _Cnemidophorus deppei infernalis_, _Sceloporus horridus oligoporus_, _Sceloporus pyrocephalus_, and _Urosaurus gadowi_.

_Salvadora mexicana_ inhabits only the arid scrub forest at elevations from sea level to about 1000 meters.

~Sibon nebulatus~ (Linnaeus)

_Coluber nebulatus_ Linnaeus, Systema naturae, ed. 10, 1, p.
222, 1758.--Africa (in error). Type locality restricted to
Jicaltepec, Veracruz, Mexico, by Smith and Taylor
(1950a:349).

_Sibon nebulatus_, Taylor, Univ. Kansas Sci. Bull., 26:473,
November 27, 1940.

Aquila.

The one specimen from Michoacan was collected by Peters (1954:30) in tropical semi-deciduous forest on the coastal foothills of the Sierra de Coalcoman. As presently known, the range of this species in western Mexico extends from Chiapas to Nayarit. Throughout this region the species avoids scrub forest; this may explain its absence in the Balsas-Tepalcatepec Valley.

~Sonora michoacanensis michoacanensis~ (Duges)

_Contia michoacanensis_ Duges, _in_ Cope, Proc. Amer.
Philos. Soc., 22:178, 1885.--Michoacan. Type locality
restricted to Apatzingan, Michoacan, Mexico, by Smith and
Taylor (1950a:335).

_Sonora michoacanensis michoacanensis_, Stickel, Proc. Biol.
Soc. Washington, 56:116, October 19, 1943.

Apatzingan (3); Coalcoman (3); 12 km. S of Tzitzio.

These specimens, together with all known specimens from the Sierra del Sur in Guerrero (KU 23790-1, MVZ 45123) and the upper Balsas Basin in Puebla (UIMNH 41688), are referable to _S. m. michoacanensis_. The dorsal pattern consists of a highly variable number of cross-bands of red, white, and black. In the specimens from Michoacan there are as many as 17 red cross-bands on the body. One specimen from Apatzingan (CNHM 37141) has just behind the head a white band, bordered on either side by a narrow black band; posteriorly the body is uniform red. Two specimens from Coalcoman (UMMZ 109905-6) have respectively 11 and 13 red cross-bands and 20 and 17 white cross-bands, and the posterior part of the body is devoid of red color. Other specimens from these localities have red, black, and white cross-bands throughout the length of the body.

_Sonora michoacanensis michoacanensis_ is distinguished from _S. michoacanensis mutabilis_ by the presence of cross-bands on the tail in the latter (Stickel, 1943:116). One specimen from Coalcoman (UMMZ 109904) has one narrow band on the tail; all others from Michoacan have uniformly red tails.

Apparently _Sonora michoacanensis michoacanensis_ ranges in semi-arid and arid habitats from the upper Balsas Basin in Puebla westward to the lower slopes of the Sierra de Coalcoman, whereas _S. m. mutabilis_ lives in foothills of the Sierra Madre Occidental from southern Jalisco to Nayarit. Zweifel (1959b:6) presented evidence to show that specimens of _S. m. mutabilis_ supposedly from "Distrito Federal" probably bear erroneous locality data.

~Tantilla bocourti~ (Guenther)

_Homalocranium bocourti_ Guenther, Biologia
Centrali-Americana, Reptilia, p. 149, 1895.--Guanajuato,
Guanajuato, Mexico.

_Tantilla bocourti_, Cope, Amer. Nat., 30:1021, December,
1896.

Carapan; Patzcuaro (2); between Zitacuaro and Rio Tuxpan
(11).

This small snake is an inhabitant of the coniferous forests and the pine-oak forests on the Cordillera Volcanica. Data on the series from between Zitacuaro and the Rio Tuxpan were given by Taylor (1940c:481).

~Tantilla calamarina~ Cope

_Tantilla calamarina_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 18:320, February 13, 1867.--Guadalajara,
Jalisco, Mexico.

Apatzingan; La Placita.

Although this snake has been collected at high elevations along the rim of the Mexican Plateau in Nayarit, Jalisco, Mexico, and Puebla, the specimens from Michoacan are from arid scrub forest at elevations of less than 400 meters. The species has been found in similar habitats in Colima (Oliver, 1937:24) and in Sinaloa and the Tres Marias Islands (Zweifel, 1960:110).

~Toluca lineata lineata~ Kennicott

_Toluca lineata_ Kennicott, _in_ Baird, Report on the United
States and Mexican boundary survey, 2, Reptiles, p. 23,
1859.--Valley of Mexico.

_Toluca lineata lineata_, Taylor and Smith, Univ. Kansas
Sci. Bull., 28:343, May 15, 1942.

Capacuaro; Carapan (12); Cheran (23); Cojumatlan; Los Reyes;
Morelia (2); Nahuatzen; Paracho (10); Patzcuaro (17);
Uruapan (2).

This small snake is an inhabitant of the coniferous forests between elevations of about 1550 and 2800 meters. Not infrequently, individuals have been found in pine-oak forest within these elevations.

The generic status of _Toluca_ is unsettled. Taylor and Smith (1942b) separated _Toluca_ from _Conopsis_ by the presence of enlarged and grooved posterior maxillary teeth in _Toluca_ and their absence in _Conopsis_. Bogert and Oliver (1945:378) suggested synonymizing _Toluca_ with _Conopsis_. Smith and Laufe (1945:12) defined the generic position of _Toluca_. Actually, in deciding the generic position of these snakes, five genera (_Ficimia_, _Gyalopion_, _Pseudoficimia_, _Conopsis_, and _Toluca_) must be considered. Of these _Ficimia_ and _Gyalopion_ are closely related; they have been placed in one genus by some workers. _Pseudoficimia_ is intermediate between _Ficimia-Gyalopion_ and _Toluca-Conopsis_. A workable definition of the supraspecific classification of these snakes must await a thorough review of the species.

~Trimorphodon biscutatus biscutatus~ (Dumeril, Bibron, and Dumeril)

_Dipsas biscutata_ Dumeril, Bibron, and Dumeril, Erpetologie
generale, 7 (pt. 2):1153, 1854.--Mexico. Type locality
restricted to Tehuantepec, Oaxaca, Mexico, by Smith and
Taylor (1950a:340).

_Trimorphodon biscutatus biscutatus_, Smith, Proc. U. S.
Natl. Mus., 91:159, November 10, 1941.

Apatzingan (11); Cofradia; Cuatro Caminos; El Sabino (2); La
Placita; La Playa (2); Lombardia (2); Nueva Italia (2); Rio
Tepalcatepec, 27 km. S of Apatzingan; Tafetan.

In the arid lowlands of the Tepalcatepec Valley and presumably also in the scrub forest of the coastal lowlands, this is an abundant snake, which is active only at night. Usually snakes of this species are found on the ground, but one large individual was observed at night in a low tree. That individual defied capture by widely opening its mouth and striking repeatedly at the collector. The excreta of one specimen contained feathers of an unidentified species of bird.

~Trimorphodon latifascia~ Peters

_Trimorphodon biscutata latifascia_ Peters, Monats. Akad.
Wiss. Berlin, p. 877, 1869.--Puebla, Mexico. Type locality
restricted to Izucar de Matamoros, Puebla, Mexico, by Smith
and Taylor (1950a:341).

_Trimorphodon latifascia_. Taylor, Univ. Kansas Sci. Bull.,
25:364, July 10, 1939.

Apatzingan (5); Casada Tzararacua; Coalcoman (2); Lombardia;
14 km. S of Lombardia; Nueva Italia; San Salvador.

In Michoacan this species has been collected in semi-arid habitats at elevations from 300 to 1430 meters in the Tepalcatepec Valley and lower slopes of the Cordillera Volcanica. In this area it occurs sympatrically with _Trimorphodon biscutatus biscutatus_.

In life, adults have a pale tan dorsal ground color and rich chocolate brown cross-bands; the eye is pale grayish tan. A juvenile from Coalcoman has black cross-bands on a pale grayish tan ground color. As stated by Schmidt and Shannon (1947:83) and Peters (1954:32), the type specimen of _Trimorphodon fasciolata_ Smith from Cascada Tzararacua is indistinguishable from specimens of _Trimorphodon latifascia_.

Seven males have 209 to 223 (216.5) ventrals; one female has 227 ventrals. The number of dark cross-bands on the body varies from 12 to 16 (13.5). The relationships of this species are with _Trimorphodon tau_ on the Mexican Plateau. In fact, additional specimens from the headwaters of the Tepalcatepec Valley and the lower slopes of the Mexican Plateau in eastern Michoacan and adjacent Jalisco may show that the two are conspecific. _Trimorphodon latifascia_ differs from _tau_ in having fewer dark cross-bands on the body and in lacking an interocular bar.

~Trimorphodon tau~ Cope

_Trimorphodon tau_ Cope, Proc. Amer. Philos. Soc., 11:151,
1869.--Quiotepec, Oaxaca, Mexico.

Emiliano Zapata (2); between Morelia and Ciudad Hidalgo;
Tacicuaro; Tangamandapio.

Two of the specimens from Michoacan (UMMZ 118948 from Tangamandapio and UIMNH 19138 from Tacicuaro) have cream-colored, Y-shaped marks on the head. These markings supposedly are characteristic of _Trimorphodon upsilon_. One specimen from Emiliano Zapata (UMMZ 118950) and one from between Morelia and Ciudad Hidalgo (EHT-HMS 21402) have a cream-colored line on the parietal suture; in another specimen from Emiliano Zapata (UMMZ 118949) the anterior end of this line is expanded, giving the appearance of an incipient "Y". Thus, the nature of the markings on the head in specimens from Michoacan is intermediate between the typical condition in _Trimorphodon tau_ and the usual condition in _T. upsilon_. Smith and Taylor (1945:148) gave the range of _Trimorphodon tau_ as: "Central Guerrero, in the Sierra Madre del Sur; central Oaxaca; and the edge of the plateau in central Michoacan." They gave the range of _Trimorphodon upsilon_ as: "Southern Chihuahua south to central Michoacan, east to central Hidalgo." Specimens referable to _T. tau_ have been found at La Joya de Salas, near Ciudad Victoria, and near Llera, Tamaulipas (see Smith and Darling, 1952:85, and Martin, 1958:74). Some of these specimens also show combinations of characteristics of _T. tau_ and _T. upsilon_. Smith and Darling (_loc. cit._) suggested that _T. tau_ and _T. upsilon_ be considered as subspecies. However, if _T. tau_ and _T. upsilon_ are subspecies, intergrades would be expected between the ranges of the two populations and not on the northeastern and southwestern periphery of their combined ranges. Instead, the limited evidence now available suggests that _T. tau_ and _T. upsilon_ are names based on a highly variable character of color pattern of the head, and that only one species is involved.

In Michoacan this species inhabits the mesquite grassland on the Mexican Plateau.

~Tropidodipsas occidentala~ Oliver

_Tropidodipsas occidentala_ Oliver, Occ. Pap. Mus. Zool.
Univ. Michigan, 360:20, November 20, 1937.--Comala, Colima,
Mexico.

Coalcoman.

This specimen was reported by Peters (1954:34), who found it beneath a rock at the mouth of a heavily wooded ravine near Coalcoman at an elevation of 950 meters. The only other known specimen is from Comala, Colima, a village, like Coalcoman, that is located near the upper limits of the arid scrub forest.

~Natrix valida isabelleae~ Conant

_Natrix valida isabelleae_ Conant, Nat. Hist. Misc., 126:7,
September 15, 1953.--Pie de la Cuesta, Laguna Coyuca,
Guerrero, Mexico.

Coahuayana; Playa Azul (2); Punto San Juan de Lima.

Three females and one male have, respectively, 133, 135, 135, and 131 ventrals, and 68, 68, 73, and 75 caudals. The grayish stippling on the posterior ventral surfaces mentioned by Conant (1953:9) is not visible on these specimens. In the small individuals from Punto San Juan de Lima and from Coahuayana there are four longitudinal rows of dark spots on the dorsum; in two large females from Playa Azul the spots are barely discernible.

All of the specimens from Michoacan were found in the coastal lowlands; those from Playa Azul were collected from a small brackish, mangrove-lined lagoon.

~Storeria storerioides~ (Cope)

_Tropidoclonium storerioides_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 17:190, December 26, 1865.--Mexican Plateau.
Type locality restricted to Tres Cumbres, Morelos, Mexico,
by Smith and Taylor (1950a:336).

_Storeria storerioides_, Garman, Mem. Mus. Comp. Zool.,
8(3):29, June, 1883.

Dos Aguas (11); Puerto de Garnica; Tancitaro (11); Tzitzio;
Uruapan; 16 km. NW of Zacapu.

Three males and six females from the Sierra de Coalcoman have, respectively, 122-128 (125.3) and 126-136 (130.0) ventrals, and 46-47 (46.7) and 38-42 (39.1) caudals. Four males and eleven females from the Cordillera Volcanica have, respectively, 124-132 (128.5) and 127-139 (136.4) ventrals, and 43-48 (44.7) and 38-44 (40.2) caudals. These data show that, although there is little difference in the number of caudals, specimens from the Sierra de Coalcoman have fewer ventrals than do specimens from the Cordillera Volcanica. Of eleven specimens from the Sierra de Coalcoman, two have black bellies. Five others from the Sierra de Coalcoman and one from Puerto de Garnica in the Cordillera Volcanica have the bellies heavily stippled with black, giving a gray appearance. Melanistic tendencies in this species have been discussed by Anderson (1960:64), who examined the specimen from Tzitzio. In life, one specimen from Dos Aguas (UMMZ 119451) had a cream-colored belly; the edges of the ventrals were dark brick-red.

In Michoacan this snake inhabits pine-oak, pine, and fir forests at elevations between 1550 and 2800 meters in the Cordillera Volcanica and the Sierra de Coalcoman. Most specimens were found beneath rocks; the one from Tzitzio was removed from the stomach of a Mexican Motmot (Anderson, 1960:66).

~Thamnophis dorsalis cyclides~ Cope

_Thamnophis cyrtopsis cyclides_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 13:299, December 28, 1861.--Cape San Lucas,
Baja California (in error). Type locality restricted to
Guanajuato, Guanajuato, Mexico, by Smith and Taylor
(1950a:330). Smith, Copeia, no. 2:140, June 8, 1951.
Milstead, Texas Jour. Sci., 5:368, September, 1953.

_Thamnophis eques eques_ (_nec._ Reuss), Smith, Zoologica,
27:106, October 23, 1942. Bogert and Oliver, Bull. Amer.
Mus. Nat. Hist., 83:356, March 30, 1945.

_Thamnophis vicinus_ Smith, Zoologica, 27:104, October 23,
1942.--Temazcal, Michoacan, Mexico.

_Thamnophis dorsalis cyclides_, Fitch and Milstead, Copeia,
no. 1:112, March 17, 1961.

Barolosa; Coalcoman; Dos Aguas (3); Los Reyes; Morelia (16);
Opopeo; Pino Gordo; Tacicuaro (16); Tancitaro (14);
Tangamandapio (2); Temazcal (2); Tzintzuntzan; Uruapan.

The snakes comprising the former _Thamnophis eques_-group have undergone extensive taxonomic and nomenclatural shuffling by Smith (1942 and 1951), Bogert and Oliver (1945), Milstead (1953), and Fitch and Milstead (1961). Smith recognized in Michoacan three members of the _T. eques_ (= _dorsalis_) complex: _eques eques_, _eques postremus_, and _vicinus_. Later, Smith (1951) showed that the specific name _eques_ had been misapplied, so that _T. eques eques_ became _T. cyrtopsis cyclides_, and _T. eques postremus_ became _T. cyrtopsis postremus_; under this arrangement _T. vicinus_ stood unchanged. In the meantime, Bogert and Oliver (1945:359) presented a reinterpretation of Smith's data and suggested that _T. vicinus_, which differs from _T. dorsalis cyclides_ only in lacking a middorsal stripe, "... is not a species, but only a pattern phase, possibly a simple mutant of _T. e. eques_" (= _T. dorsalis cyclides_, by present arrangement). Milstead (1953) agreed with Bogert and Oliver on the status of _T. vicinus_; furthermore, on the basis of only a few specimens, Milstead concluded that _T. cyrtopsis postremus_ was not subspecifically distinct from _T. cyrtopsis cyclides_. Recently, Fitch and Milstead (1961) showed that _Thamnophis dorsalis_ Baird and Girard (1853) was the correct name for the snakes that had been recognized as _Thamnophis cyrtopsis_ Kennicott (1860). Consequently, the snakes referred to _T. eques eques_ by Smith (1942) and to _T. cyrtopsis cyclides_ by Smith (1951) and Milstead (1953) are now _T. dorsalis cyclides_.

Aside from one specimen from Temazcal and nine from Morelia (paratypes of _T. vicinus_), only two other specimens completely lacking the middorsal stripe have been seen; one is a male (UMMZ 102510) having 161 ventrals and an incomplete tail from Pino Gordo, and the other is a male (CNHM 39060) from Tancitaro having 158 ventrals and an incomplete tail. A female from Tancitaro (CNHM 39061) having 153 ventrals and 77 caudals has no lateral stripes and only a narrow middorsal stripe on the anterior part of the body. Throughout the region where _T. vicinus_-like snakes have been found, typical _T. dorsalis cyclides_ occurs in much greater numbers. I concur with Bogert and Oliver in placing _T. vicinus_ as a synonym of _T. dorsalis cyclides_.

Milstead (1953) had available few specimens of _Thamnophis dorsalis_ from the Tepalcatepec Valley. The large series now in existence shows that the population in the Tepalcatepec Valley differs distinctly from that inhabiting the Mexican Plateau, Cordillera Volcanica, and Sierra de Coalcoman. Therefore the name _T. dorsalis postremus_ Smith (1942) is resurrected for the population in the Tepalcatepec Valley. _T. dorsalis cyclides_ and _T. dorsalis postremus_ differ in color pattern (Fig. 10) and in scutellation (Table 6). Specimens from the Mexican Plateau and mountain ranges have a distinct light stripe on the second and third scale rows, a dark brown dorsum having squarish black spots, and a row of dark spots on the first row of dorsal scales. Specimens from the Tepalcatepec Valley have a grayish brown dorsum having smaller and less distinct dark spots and no light stripe on the second and third scale rows; the first, second, and third rows of scales are colored like the venter. In some specimens there are small dark flecks on the first row of dorsal scales.

TABLE 6.--VARIATION IN SCUTELLATION IN THAMNOPHIS DORSALIS.

+---------------------------------+-------+---------+------------+ | Character |Mexican|Sierra de|Tepalcatepec| | |Plateau|Coalcoman| Valley | +------------------+--------------+-------+---------+------------+ | Ventrals | Female N | 31 | 2 | 32 | | | Mean | 164.0 | 156.5 | 144.6 | | | Range|153-171| 154-159 | 138-151 | | +--------------+-------+---------+------------+ | | Male N | 19 | 2 | 32 | | | Mean | 153.5 | 154.7 | 138.3 | | | Range|149-159| 149-159 | 131-141 | +------------------+--------------+-------+---------+------------+ | Caudals | Female N | 28 | 2 | 29 | | | Mean | 83.8 | 81.0 | 73.4 | | | Range|80-100 | 79-83 | 70-79 | | +--------------+-------+---------+------------+ | | Male N | 14 | 2 | 28 | | | Mean | 78.0 | 72.0 | 68.5 | | | Range| 71-87 | 72 | 63-73 | +------------------+--------------+-------+---------+------------+

One specimen from Uruapan (1550 meters) and one from Coalcoman (950 meters) are intermediate in color pattern between _T. dorsalis cyclides_ and _T. dorsalis postremus_. Both have indistinct lateral stripes and only small dark spots below the stripes. In scutellation these specimens are like _T. dorsalis cyclides_.

In Michoacan _Thamnophis dorsalis cyclides_ has been collected in a variety of habitats on the Mexican Plateau: pine-oak forest, fir forest, marshes, and cleared land from 1550 to 2800 meters. In the Sierra de Coalcoman one was taken in broad-leafed forest at 950 meters, three in pine-oak forest at 2100 meters, and one in pine forest at 2300 meters.

~Thamnophis dorsalis postremus~ Smith

_Thamnophis eques postremus_ Smith, Zoologica, 27:109,
October 23, 1942.--El Sabino, Michoacan, Mexico.

_Thamnophis cyrtopsis postremus_ Smith, Copeia, no. 2:140,
June 8, 1951.

_Thamnophis cyrtopsis cyclides_ (part), Milstead, Texas
Jour. Sci., 5:368, September, 1953.

_Thamnophis dorsalis postremus_, Fitch and Milstead, Copeia,
no. 1:112, March 17, 1961.

Apatzingan (31); Capirio (2); Charapendo; Cuatro Caminos
(22); El Sabino; Lombardia (9); Nueva Italia (8); Uruapan
(3).

The reasons for recognizing the population of _Thamnophis dorsalis_ in the Tepalcatepec Valley as distinct from that on the surrounding highlands are presented in the discussion of _Thamnophis dorsalis cyclides_. In certain features of coloration and in the low numbers of ventrals and caudals, _T. dorsalis postremus_ shows more resemblance to _T. dorsalis sumichrasti_ than to _T. dorsalis cyclides_. According to Milstead (1953:367), _T. dorsalis cyclides_ ranges southward from the Rio Balsas in southwestern Mexico. If specimens could be obtained from the upper Balsas Basin they might show that _T. dorsalis postremus_ inhabits that extensive basin.

In the Tepalcatepec Valley _T. dorsalis postremus_ is most frequently found at night in the rainy season, at which time the snakes are abundant near temporary pools where frogs are breeding. The absence of specimens from the coastal lowlands of Guerrero, Michoacan, and Colima indicate that, although the species inhabits the lowlands of the Tepalcatepec Valley, its range does not include the coastal lowlands.

A female (UMMZ 119402 from Cuatro Caminos) having 139 ventrals and a body length of 576 mm., on June 20, 1958, gave birth to 25 young, of which 18 (9 males and 9 females) were preserved. In body length the males varied from 132 to 141 (137.3) mm.; the females, 125 to 137 (133.1) mm. In tail length the males varied from 38 to 44 (42.4) mm.; females, 35 to 42 (39.7) mm. The males have 138 to 147 (142.2) ventrals and 70 to 75 (72.9) caudals; females have 131 to 140 (135.8) ventrals and 63 to 71 (67.0) caudals.

~Thamnophis eques eques~ (Reuss)

_Coluber eques_ Reuss, Zool. Misc., p. 152, 1834.--Mexico.
Type locality restricted to Guadalajara, Jalisco, Mexico, by
Smith and Taylor (1950a:334).

_Thamnophis macrostemma macrostemma_, Smith and Taylor,
Bull. U. S. Natl. Mus., 187:163, October 5, 1945.

_Thamnophis subcarinata subcarinata_, Smith, Herpetologica,
5:63, May 31, 1949.

_Thamnophis eques eques_, Smith, Copeia, no. 2:139, June 8,
1951.

Jiquilpan; Lago de Cuitzeo; Lago de Patzcuaro (17);
Patzcuaro (5); Tangancicuaro; Tupataro (2); Undameo; Zacapu.

Although this snake has been collected in open pine-oak forest and in oak-bunch grass associations, it seems to reach its greatest abundance in marshes on the Mexican Plateau at elevations of 1550 to 2300 meters.

~Thamnophis melanogaster canescens~ Smith

_Thamnophis melanogaster canescens_ Smith, Zoologica,
27:117, October 23, 1942.--Chapala, Jalisco, Mexico.

Lago de Cuitzeo (5); Lago de Patzcuaro; Patzcuaro;
Tacicuaro; Tangamandapio (2).

This species of garter snake seems to be most abundant in the marshes adjacent to the lakes on the Mexican Plateau in Michoacan and Jalisco. At these elevations (1550 to 2200 meters) it often is found in association with _Thamnophis eques eques_ and sometimes with _Thamnophis dorsalis cyclides_. On June 11, 1958, individuals of this species were found in a hyacinth-choked marsh at Tangamandapio at night.

One specimen from Tangamandapio (UMMZ 119414) had, in life, a dark chocolate brown dorsum, reddish brown sides, and cream-colored belly, chin, and labials. There were no longitudinal dorsal stripes.

~Thamnophis scalaris scaliger~ (Jan)

_Tropidonotus scaliger_ Jan, Elenco sistematico degli Ofidi,
p. 70, 1863.--No type locality designated. Type locality
restricted to Mexico City, Distrito Federal, by Smith and
Taylor (1950a:329).

_Thamnophis scalaris scaliger_, Smith, Zoologica, 27:103,
October 23, 1942.

Cerro Tancitaro (2); Nahuatzen; Opopeo; 26 km. S of
Patzcuaro.

The few specimens of this species from Michoacan have been collected at elevations from 1800 to 3400 meters in pine or fir forest in the Cordillera Volcanica.

~Micrurus distans michoacanensis~ (Duges)

_Elaps diastema michoacanensis_ Duges, La Naturaleza, ser.
2, 1:487, 1891.--Michoacan. Type locality restricted to
Apatzingan, Michoacan, Mexico, by Smith and Taylor
(1950a:335).

_Micrurus distans michoacanensis_, Zweifel, Amer. Mus.
Novitates, 1953:11, June 26, 1959.

Apatzingan (6).

All specimens were collected in the arid scrub forest of the Tepalcatepec Valley. The number of black rings on the body varies from six to eleven. In this respect they agree with the diagnosis of this subspecies presented by Zweifel (1959b:9).

~Micrurus laticollaris~ (Peters)

_Elaps marcgravii laticollaris_ Peters, Monats. Akad. Wiss.
Berlin, p. 877, 1869.--Izucar de Matamoros, Puebla, Mexico.

_Micrurus laticollaris_, Schmidt, Publ. Field Mus. Nat.
Hist., zool. ser., 20:39, December 11, 1933.

El Sabino (2); Lombardia.

This species ranges throughout the Balsas-Tepalcatepec Basin westward into Colima; specimens from Michoacan were collected in arid scrub forest at elevations from 500 to 1050 meters. The limited observations on _Micrurus distans michoacanensis_ and _M. laticollaris_ indicate that, at least in the Tepalcatepec Valley, _M. laticollaris_ seems to inhabit slightly more mesic areas than does _M. distans michoacanensis_.

~Pelamis platurus~ (Linnaeus)

_Anguis platura_ Linnaeus, Systema naturae, ed. 12, 1:391,
1766.--Pine Island, Pacific Ocean.

_Pelamis platurus_, Gray, Ann. Philos., p. 15, 1825.

Boca de Apiza.

In November, 1955, Alfonzo Gonzales, a geographer from the University of Texas, observed sea snakes on the beaches of Michoacan. In May, 1956, Donald D. Brand of the University of Texas gave me one specimen of _Pelamis platurus_ that he obtained on March 2, 1956, at Boca de Apiza. Furthermore, he supplied me with the following observations based on his field work along the coast of Michoacan from the Rio Coahuayana to Maruata from March 1, to April 15, 1956. At that time many sea snakes were observed; in some places living and dead individuals were seen on the beaches; innumerable snakes were seen in the surf. When live individuals were taken from the beach and thrown into the ocean, they usually swam to shore. Many partially eaten individuals were seen protruding from crab holes. Inquiries among the natives resulted in the following information: Sea snakes are frequently seen between November and April, but most commonly in March and April, at which time the water is cold. The natives referred to the sea snakes as "culebra del mar." Most natives said that the snakes were not poisonous; others did not know of any venomous properties. In May, 1956, I worked the coastal region from the Rio Coahuayana to La Placita and saw no sea snakes. In the summer of 1950 James A. Peters, and in the summer of 1951 I worked nearly the entire coastal region of Michoacan; during that time no _Pelamis_ were seen. Insofar as I know, this is the first report of such seasonal activity in _Pelamis platurus_ in the Americas.

~Agkistrodon bilineatus bilineatus~ Guenther

_Ancisdrodon bilineatus_ Guenther, Ann. Mag. Nat. Hist., ser.
3, 12:364, 1863.--Pacific coast of Guatemala.

_Agkistrodon bilineatus bilineatus_, Burger and Robertson,
Univ. Kansas Sci. Bull., 34 (1):213, October 1, 1951.

Apatzingan; El Sabino; La Playa; Los Reyes.

All specimens from Michoacan are from inland localities between 300 and 1500 meters. The one from Los Reyes (USNM 46416) was collected by Nelson and Goldman on February 13, 1903. The elevation of Los Reyes (1500 meters) seems unusually high for this species, but otherwise there is no reason to doubt the authenticity of the record. Goldman (1951:192) in his description of Los Reyes stated: "Los Reyes is near the boundary between the Lower Austral and Arid Upper Tropical Zones but is preponderantly tropical in zonal character. The regular crops are mainly sugar cane, rice, and corn." Thus the biotic features of the area are not noticeably different from those at El Sabino and La Playa at lower elevations. The development of extensive agriculture through irrigation in the Tepalcatepec Valley and planting of rice and sugar-cane in that area may produce a more widespread habitat for this snake.

The absence of specimens from the coastal lowlands is due solely to inadequate collecting; the natives there know the snake and report that it is not uncommon in certain areas.

~Crotalus basiliscus basiliscus~ (Cope)

_Caudisonia basilisca_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, September 30, 1864.--Colima. Type locality
restricted to Colima, Colima, Mexico, by Smith and Taylor
(1950a:328).

_Crotalus basiliscus basiliscus_, Gloyd, Nat. Hist. Misc.,
17:1, April 23, 1948.

Apatzingan (4); Camachines; Coalcoman; El Ticuiz.

Specimens from southern Michoacan have fewer ventrals and caudals than do those from the northern part of the range; three males and three females have, respectively, 178, 182, 182, 185, 186, and 188 ventrals, and 27, 28, 29, 22, 29, and 29 caudals. Klauber (1952:81) gave the following data for _Crotalus basiliscus_ (based on specimens from the entire range, except Oaxaca): ventrals in males, 179-201 (191.4), in females, 185-206 (197.6); caudals in males, 26-36 (30.7), in females, 21-29 (24.4). Klauber (1952:84) remarked that the one specimen that he had seen from Apatzingan had fewer ventrals and caudals than most other specimens. The low numbers of ventrals and caudals in specimens from Michoacan, as compared with more northern populations, may be indicative of a trend in the reduction of the numbers of these scutes from north to south. The southernmost examples of _Crotalus basiliscus_ (_Crotalus basiliscus oaxacus_ from Oaxaca) have 172-175 ventrals and 21 caudals (Gloyd, 1948).

In Michoacan _Crotalus basiliscus basiliscus_ has been found in arid habitats on the coast, in the Tepalcatepec Valley, and in the lower parts of the Sierra de Coalcoman. All specimens are from localities below 1070 meters in elevation.

~Crotalus durissus culminatus~ Klauber

_Crotalus durissus culminatus_ Klauber, Bull. Zool. Soc. San
Diego, 26:65, August 8, 1952.--El Sabino, Michoacan, Mexico.

El Sabino (18).

These specimens are part of the type series and were collected by Hobart M. Smith near the upper limits of the arid scrub forest at an elevation of about 1050 meters on the lower slopes of the Cordillera Volcanica at the northern edge of the Tepalcatepec Valley. They were discussed in detail by Klauber (1952:66-70).

~Crotalus intermedius intermedius~ Troschel

_Crotalus intermedius_ Troschel, _in_ von Mueller, Reisen in
Vereiningten Staaten, Canada und Mexico, vol. 3, p. 613,
1865.--Type locality unknown.

_Crotalus intermedius intermedius_, Klauber, Bull. Zool.
Soc. San Diego, 26:9, August 8, 1952.

Cerro Tancitaro.

The one specimen is from the pine forests on the Cordillera Volcanica. At the present time this species is known from scattered localities in west-central Veracruz, Oaxaca, Michoacan, and as _Crotalus intermedius omiltemanus_ in Central Guerrero. Apparently it is restricted to montane environments.

~Crotalus molossus nigrescens~ Gloyd

_Crotalus molossus nigrescens_ Gloyd, Occ. Pap. Mus. Zool.
Univ. Michigan, 325:2, January 28, 1936.--Four miles west of
La Colorada, Zacatecas, Mexico.

Carapan; Los Conejos; Patzcuaro; Tacicuaro (5).

In Michoacan this species has been found in pine forests between 1550 and 2300 meters in the Cordillera Volcanica. I expected to find it in the Sierra de Coalcoman, but inquiries among the natives living in the pine forests of that mountain range revealed that the people there have no knowledge of a large species of rattlesnake.

~Crotalus polystictus~ (Cope)

_Caudisonia polysticta_ Cope, Proc. Acad. Nat. Sci.
Philadelphia, 17:191, December 26, 1865.--Tableland of
Mexico. Type locality restricted to Tupataro, Guanajuata,
Mexico, by Smith and Taylor (1950a:330).

_Crotalus polystictus_ Cope, _in_ Yarrow, Wheeler's Rept.
Geog. Geol. Expl. Surv. W. 100th. Mer., vol. 5, p. 533,
1875.

Tacicuaro (4); Tupataro (2).

Formerly this species was abundant in the marshes around Lago de Chapala. The draining of these marshes probably resulted in reducing the numbers of these rattlesnakes. The species is known only from the Mexican Plateau at elevations of 1450 to 2400 meters.

~Crotalus pusillus~ Klauber

_Crotalus pusillus_ Klauber, Bull. Zool. Soc. San Diego,
26:34, August 8, 1952.--Tancitaro, Michoacan, Mexico.

Acuaro de las Lleguas (2); Carapan; Cerro Tancitaro (16);
Dos Aguas (12).

Aside from the type series of _Crotalus pusillus_ from Cerro Tancitaro and one specimen from Carapan referred to the species by Klauber (1952:38), there are fourteen specimens from the Sierra de Coalcoman. These specimens (UMMZ 112566-7, 118591-9, 118601, 121512-3) are like _Crotalus pusillus_ from Cerro Tancitaro in having the prefrontals paired, a black proximal rattle, and the underside of the tail black. The prefrontals are bordered posteriorly by one scale in two specimens, by two scales in three specimens, and by three scales in the other nine. The snakes from the Sierra de Coalcoman have 40 to 46 (42) dorsal body blotches. Ten males have 150-158 (154.4) ventrals and 29-33 (31.0) caudals; two females have 157 and 160 ventrals, and 25 and 27 caudals. The largest specimen is a male having a body length of 545 mm. and a tail length of 63 mm. The only noticeable difference between the specimens from the Sierra de Coalcoman and the topotypic series is that the latter have fewer dorsal blotches; the range of variation is 33 to 46 (39.8).

Most specimens of this species have a grayish brown dorsum and dark brown dorsal blotches. Two specimens from Dos Aguas (UMMZ 118596 and 118599) are pale brown above and have indistinct blotches.

One specimen from Dos Aguas regurgitated a large _Gerrhonotus imbricatus imbricatus_; of two others from the same locality, one regurgitated a _Sceloporus bulleri_ and an _Eptesicus fuscus_. The latter specimen was collected at the entrance of a small cave, where it probably had captured the bat.

In the Cordillera Volcanica _Crotalus pusillus_ has been obtained in pine-oak forest at elevations between 1550 and 1800 meters. In the Sierra de Coalcoman two specimens were taken in pine forest at an elevation of 2300 meters; ten other were found beneath rocks and logs in pine-oak forest at an elevation of 2100 meters.

~Crotalus triseriatus aquilus~ Klauber

_Crotalus triseriatus aquilus_ Klauber, Bull. Zool. Soc. San
Diego, 26:24, August 8, 1952.--Alvarez, San Luis Potosi,
Mexico.

Morelia (10); Tacicuaro (2).