The Amphibians and Reptiles of Michoacan, Mexico Part 17

~Typhlops braminus~ (Daudin)

_Eryx braminus_ Daudin, Hist.... des reptiles, 7:279, 1803.--Vazagapatam, India.

_Typhlops braminus_, Cuvier, Regne animal, ed. 2, 2:73, 1829.

Apatzingan; Arteaga.

Both specimens known from Michoacan were collected by Gadow in 1908.

Peters (1954:20) remarked that the specimen from Arteaga probably does not indicate a rapid spreading of the species, which most likely was introduced into Mexico at the time that vessels were stopping at Acapulco from the Philippines (Taylor, 1940b:444), but instead may indicate that pack trains from Acapulco pa.s.sed through the Sierra de Coalcoman. The occurrence of this snake along a long-used _camino_ substantiates this belief.

~Leptotyphlops bressoni~ Taylor

_Leptotyphlops bressoni_ Taylor, Copeia, No. 1:5, March 9, 1939.--Hacienda El Sabino, Michoacan, Mexico.

El Sabino.

This species still is known definitely only from the type specimen collected on the lower slopes of the Cordillera Volcanica at the northern edge of the Tepalcatepec Valley. A specimen (now lost) reported from Aguililla by Cope (1887:63) possibly represents this species (see Smith and Taylor, 1945:21, and Peters, 1954:20).

~Leptotyphlops gadowi~ Duellman

_Leptotyphlops gadowi_ Duellman, Copeia, No. 2:93, May 29, 1956.--Apatzingan, Michoacan, Mexico.

Apatzingan.

No additional specimens of this species have been collected since the species was described by Duellman (1956b:93). Data given with the specimen by Gadow indicate that it came from his camp above Apatzingan at an elevation of about 800 meters. Although the exact position of this camp is unknown, the lower slopes of the Cordillera Volcanica above Apatzingan usually support arid scrub forest at elevations below 1000 meters. Therefore, this species probably is an inhabitant of the arid scrub forest.

~Leptotyphlops phenops bakewelli~ Oliver

_Leptotyphlops bakewelli_ Oliver, Occ. Pap. Mus. Zool. Univ.

Michigan, 360:16, November 20, 1937.--Paso del Rio, Colima, Mexico.

_Leptotyphlops phenops bakewelli_, Smith, Proc. U. S. Natl.

Mus., 93:445, October 29, 1943.

La Placita (4); La Salada; Ostula.

The five specimens from the coastal lowlands are from elevations of less than 150 meters; these were collected by Peters (1954:20); the specimen from La Salada is from an elevation of 580 meters in the Tepalcatepec Valley. Peters (_loc. cit._) remarked that the rostral and the tip of the tail that were described as white by Oliver (1937:17) actually are sulphur-yellow in life.

~Loxocemus bicolor~ Cope

_Loxocemus bicolor_ Cope, Proc. Acad. Nat. Sci.

Philadelphia, 13:77, June 30, 1861.--La Union, El Salvador.

_Loxocemus sumichrasti_ Bocourt, Ann. Sci. Nat., ser. 6, 4:1, 1876.--Tehuantepec, Oaxaca, Mexico.

Apatzingan (6); La Orilla; Lombardia.

As noted by Peters (1954:21), this species was not recorded from Michoacan by Smith and Taylor (1945:27), but Gadow (1930:30) collected a specimen at La Orilla in 1908. This specimen (BMNH 1914.1.28.124) is a male having 235 ventrals and 47 caudals, a dark brown dorsum, and cream-colored l.a.b.i.als and venter. The anterior chin-shields are considerably longer than the scales bordering the chin-shields. In these characters this specimen agrees with the diagnosis of _Loxocemus bicolor_ given by Taylor (1940c:447), who revived _Loxocemus sumichrasti_ Bocourt. Of the six specimens from Apatzingan in the Tepalcatepec Valley, three males have 243 to 253 (246.6) ventrals and 44 to 45 (44.3) caudals; three females have 238 to 247 (244.0) ventrals and 42 to 44 (43.0) caudals. Certain characters of scutellation utilized by Taylor for separating _L. bicolor_ and _L. sumichrasti_ are inconsistent in this series. The chin-shields are longer than the adjacent scales, like those ill.u.s.trated in _L. bicolor_ by Taylor (_op. cit._, fig. 1).

The relative lengths of the prefrontal and internasal sutures are subequal, or the prefrontal suture is slightly longer. Thus, in these characters of scutellation these snakes are like _L. bicolor_, but in coloration they are like _L. sumichrasti_; the dorsal color in life was an iridescent dark bluish gray, and the belly was pale gray or bluish gray.

The supposed differences in scutellation between _L. bicolor_ and _L.

sumichrasti_ have been questioned by Woodbury and Woodbury (1944:360); these authors treated _L. sumichrasti_ as a subspecies of _L. bicolor_.

As pointed out by Zweifel (1959b:5), such an arrangement is not tenable, for, although individuals with each kind of color pattern have not been collected together at any one locality, the over-all geographic picture is one of sympatric distribution. Only snakes having the coloration of _L. sumichrasti_ have been collected in the Balsas-Tepalcatepec Basin. I agree with Zweifel (_loc. cit._) that on the basis of morphological similarities and sympatric distribution, _L. bicolor_ and _L.

sumichrasti_ seem to be dimorphic phases of the same species, showing no more striking differences in coloration than _Lampropeltis getulus californiae_, a now cla.s.sical example of pattern dimorphism in snakes.

In Michoacan, as in other parts of its range, _Loxocemus bicolor_ inhabits arid scrub forest environments at low elevations.

~Boa constrictor imperator~ Daudin

_Boa imperator_ Daudin, Hist. nat.... des reptiles, 5:150, 1803.--Mexico. Type locality restricted to Cordoba, Veracruz, Mexico, by Smith and Taylor (1950a:347).

_Boa constrictor imperator_, Forcart, Herpetologica, 7:199, December 31, 1951.

Apatzingan (4); Coalcoman; El Sabino (2); La Placita; La Playa (2); Lombardia; Nueva Italia (2); Rio Cachan; Rio Marquez, 13 km. SE of Nueva Italia; Rio Nexpa; Volcan Jorullo.

These specimens have come from a variety of habitats from elevations of less than 1,000 meters. The species seems to be equally abundant in the broad-leafed semi-deciduous forests of the coastal foothills and in the arid Tepalcatepec Valley. In the latter area most of the specimens were collected at night.

~Coniophanes fissidens dispersus~ Smith

_Coniophanes fissidens dispersus_ Smith, Proc. U. S. Natl.

Mus., 91:106, November 13, 1941.--El Limoncito, Guerrero, Mexico.

Arteaga.

Further collecting in southern Michoacan has failed to add additional material of this species, which is known in the state from the one specimen collected by Gadow in 1908. The species possibly ranges throughout the coastal foothills of the Sierra de Coalcoman. Peters (1954:21) described the specimen from Arteaga.

~Coniophanes lateritius lateritius~ Cope

_Coniophanes lateritius_ Cope, Proc. Acad. Nat. Sci.

Philadelphia, 13:524, March 31, 1862.--Guadalajara, Jalisco, Mexico.

_Coniophanes lateritius lateritius_, Smith and Grant, Herpetologica, 14:20, April 25, 1958.

Nineteen km. S of Arteaga.

The one specimen available from Michoacan of this apparently rare species was discussed by Wellman (1959:127), who pointed out that although the specimen was geographically intermediate between the subspecies _C. l. lateritius_ (Jalisco and Nayarit) and _C. l.

melanocephalus_ (Morelos and Puebla), the specimen (UMMZ 118954) was like _C. l. lateritius_ in scutellation and in color pattern differed from other known specimens of the species in having had in life a pale orange, instead of a brick-red, dorsum. Additional specimens from the Sierra de Coalcoman will be required in order to determine whether this specimen is a representative of an orange-colored population or merely is aberrant in coloration.

The present specimen is from an elevation of 900 meters in oak forest on the southern slopes of the Sierra de Coalcoman; other locality records for the species indicate that it inhabits broad-leafed forest in foothills from Nayarit to Puebla.