~Conophis vittatus vittatus~ Peters
_Conophis vittatus_ Peters, Monats. Akad. Wiss. Berlin, p.
519, 1860.--No type locality given. Type locality restricted to Laguna Coyuca, Guerrero, Mexico, by Smith and Taylor (1950a:331).
_Conophis vittatus vittatus_, Smith, Jour. Washington Acad.
Sci., 31:119, March 17, 1941.
Arteaga; Coalcoman (4); La Playa; 19 km. S of Tzitzio.
All specimens of this terrestrial snake have been collected in areas of scrub forest between 800 and 1100 meters above sea level. Since the species is known from the coastal regions of Guerrero and Colima, its absence from the cost of Michoacan is unexplainable; probably the lack of specimens from these areas is due solely to inadequate collecting.
~Conopsis biserialis~ Taylor and Smith
_Conopsis biserialis_ Taylor and Smith, Univ. Kansas Sci.
Bull., 28 (2):333, November 12, 1942.--Ten miles west of Villa Victoria, Mexico, Mexico.
Capacuaro (5); Cerro San Andres; Cheran; Ciudad Hidalgo; Macho de Agua (4): Patzcuaro (8); Tancitaro (24); Uruapan (9); 24 km. SE of Zitacuaro (14).
This species is abundant in the coniferous forests at elevations from 1550 to 2800 meters throughout the Cordillera Volcanica; apparently it does not occur in the Sierra de Coalcoman.
On August 1, 1956, a copulating pair was found beneath a rock at Capacuaro.
One of the best characters to distinguish this species from _Toluca lineata_, which occurs with _Conopsis_ throughout its range in Michoacan, is the presence of large, black ventral blotches in _Conopsis biserialis_, as contrasted with the two rows of small black spots in _Toluca lineata_.
~Conopsis nasus~ Gunther
_Conopsis nasus_ Gunther, Catalogue... snakes... British Museum, p. 6, 1858.--California (in error). Type locality restricted to Guanajuato, Guanajuato, Mexico, by Smith and Taylor (1950a:330).
Carapan (2); Erongaricuaro; Maravatio (3); Morelia (2); Nahuatzen; Patzcuaro (7); Tacicuaro (8); Tancitaro.
This species has been collected in oak, pine-oak, and fir forests at elevations of 1900 to 2450 meters on the mountains rising from the Mexican Plateau. It does not seem to be so abundant as _Conopsis biserialis_. Sufficient ecological data to determine differences in habitat between the two species have not been compiled.
~Diadophis dugesi~ Villada
_Diadophis punctatus dougesii_ Villada, La Naturaleza, 3:226, 1875.--Potreros de Balbuena, Distrito Federal, Mexico.
_Diadophis dugesii_, Blanchard, Bull. Chicago Acad. Sci., 7:51, December 30, 1942.
Morelia (2); Patzcuaro; Quiroga.
Apparently this snake is uncommon in Michoacan. It has been found only at elevations of 1900 to 2200 meters in pine and pine-oak forests on the mountains rising from the Mexican Plateau.
~Dryadophis melanolomus stuarti~ Smith
_Dryadophis melanolomus stuarti_ Smith, Proc. U. S. Natl.
Mus., 93:418, October 29, 1943.--Acapulco, Guerrero, Mexico.
Coahuayana; El Ticuiz; La Placita (3); Punto San Juan de Lima; Punto San Telmo.
The few specimens indicate that in Michoacan, as elsewhere on the Pacific coast of Mexico, this species is restricted to forested regions on the coastal plain. It does not occur in the Tepalcatepec Valley.
The coloration, in life, of a juvenile (UMMZ 114604) is as follows: The dorsum is uniform pale grayish tan on posterior one-third of body and on tail; anteriorly there are pale grayish tan middorsal blotches separated by grayish white inters.p.a.ces, which are about one-half the length of the blotches. Posteriorly the blotches are less distinct, fading into the uniform grayish tan ground color of the posterior part of the body. The blotches extend laterally onto the fourth and fifth scale rows. Large squarish lateral intercalary blotches of darker brown interconnect with the dorsal blotches. The top of the head is pale olive-brown; a dark brown pos...o...b..tal stripe extends from the eye to the posterior edge of the last upper l.a.b.i.al. The l.a.b.i.als, chin, and ventrals 1-30 are creamy white, changing to a dusty cream-color posteriorly; the chin and ventrals 1-30 are heavily spotted with dark brown. The iris is a cream-color above and chocolate brown below; the tongue is blue.
~Drymarchon corais rubidus~ Smith
_Drymarchon corais rubidus_ Smith, Jour. Washington Acad.
Sci., 31:474, November 11, 1941.--Rosario, Sinaloa, Mexico.
Apatzingan (5); Arroyo El Salto; Arteaga; Capirio; El Sabino (7); La Palma; La Placita; Ostula; San Juan de Lima.
Not all of the specimens from Michoacan are typical in color pattern of this subspecies, as defined by Smith (1941a:475). All specimens from the Tepalcatepec Valley are uniformly black above; they have reddish or cream-colored chins and the anterior two-thirds of the belly salmon-pink or reddish buff. Individuals from the Sierra de Coalcoman (Arteaga and Arroyo El Salto) are like those from the Tepalcatepec Valley. Three specimens from the coastal lowlands differ noticeably in color pattern:
UMMZ 104504, adult male (Ostula).--Pale brown above flecked with black anteriorly; at midbody, flecks form narrow transverse bands that become progressively wider posteriorly, until on tail no brown pigment evident, all ventrals reddish buff, except last eight, which are black.
UMMZ 104602, adult female (La Placita).--Black above, reddish cross-bands and flecks on all of body; dorsal and ventral surfaces of tail black; chin cream-color and entire belly reddish buff.
UMMZ 114626, adult male (San Juan de Lima).--Black above; dull rust-colored cross-bands on anterior half of body; chin white; belly rust-colored on anterior two-thirds of body and black posteriorly.
One specimen from La Palma on the Mexican Plateau (KU 29275) has the top of the head an olive-color, the entire dorsum black, the chin and ventrals 1-42 a cream-color, remainder of venter black, and all of the l.a.b.i.als heavily barred with black. A juvenile from Capirio in the Tepalcatepec Valley (UMMZ 114627) is black above and has pale olive-colored flecks on the anterior one-third of the body; the top of the head is dark olive-brown, and the sides of the head are somewhat paler. Anteriorly the belly is a cream-color; posteriorly it is black.
The specimens from the Tepalcatepec Valley are typical of _Drymarchon corais rubidus_. Those from the coastal lowlands differ in having large areas of brown or red pigment on the dorsum, a condition not mentioned by Smith in his description of the subspecies. The specimen from La Palma, like many others from various localities on the Mexican Plateau, resembles in certain characters _D. corais orizabensis_ (Smith, _op.
cit._: 477). Our knowledge of the geographical variation in coloration in this species is incomplete; many populations have been a.s.signed to subspecific rank without justification.
In Michoacan this species is found from sea level to 1350 meters in the Sierra de Coalcoman and to 1300 meters at La Palma on Lago de Chapala.
It has been collected in scrub forest, semi-deciduous broad-leafed forest, and oak forest.
~Drymobius margaritiferus fistulosus~ Smith
_Drymobius margaritiferus fistulosus_ Smith, Proc. U. S.
Natl. Mus., 92:383, November 5, 1942.--Miramar, Nayarit, Mexico.
Apatzingan (3); Coahuayana; Coalcoman (3); El Sabino (3); El Ticuiz; 12 km. S of Tzitzio.
This snake is abundant in the lowlands of the state; the few specimens listed above are indicative not of the rarity, but rather of the speed and agility, of this diurnal snake. It most frequently is found near water, where there is a dense growth of vegetation. One individual was observed in a large pool inhabited by several small _Rana pipiens_, and another was seen along the bank of a hyacinth-choked river channel. A third individual was captured while it was in pursuit of a _Cnemidophorus_.
This species has been collected on the coastal lowlands and seaward foothills of the Sierra de Coalcoman and in the Tepalcatepec Valley to elevations of 1150 meters.
~Elaphe triaspis intermedia~ (Boettger)
_Pityophis intermedius_ Boettger, Ber. Offen. Vereins.
Naturk., 22:148, 1883.--Mexico. Type locality restricted to Hacienda El Sabino, Michoacan, Mexico, by Dowling (1960:74).