_Salvadora Bairdii_ Jan. Icon. gener. ophid., livr. 2, pl. 3, fig. 2, 1860.--México. Type locality restricted to Acámbaro, Guanajuato, México, by Smith and Taylor (1950a:330). Barranca Seca; Carapan; Cerro San Andrés; Cojumatlán (2); Jiquilpan; Morelia; Pátzcuaro (4); Quiroga; Sahuayo (2); Tacícuaro (12); Tancítaro (56); Uruapan (2); Zacapu (2); between Zitácuaro 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 Michoacán has revealed this kind of coloration in only one other specimen, an individual from Tacícuaro, in which the stripes diverge, but do not extend through the eye onto the loreal. Data on scutellation for the large series from Tancítaro were given by Schmidt and Shannon (1947:78), and for the series from Tacícuaro by Smith (1943:466). ~Salvadora mexicana~ (Duméril, Bibron, and Duméril) _Zamenis mexicanus_ Duméril, Bibron, and Duméril, Erpétologie genérale, 7 (pt. 1), p. 695, 1854.--Cape Corrientes, Jalisco, México. _Salvadora mexicana_ Günther, Ann. Mag. Nat. Hist., ser. 3, 12:349, 1863. Apatzingán (12); Capirio (2); El Sabino (5); Huetamo; La Placita; La Playa (4); Lombardia; Nueva Italia; Ojos de Agua de San Telmo; Oropeo; Río Cancita, 14 km. E of Apatzingán; 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 Apatzingán 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, México, by Smith and Taylor (1950a:349). _Sibon nebulatus_, Taylor, Univ. Kansas Sci. Bull., 26:473, November 27, 1940. Aquila.