Usually the 1st row of dorsal scales is dark brown; in some specimens the brown on the 1st or 7th row has faded in preservative. A few specimens have small black spots on the moderate brown background of the 1st row; in others the 1st row is only a somewhat darker brown than the ground-color. The 2nd row sometimes is a medium brown, and appears to be an additional stripe.
The ventrals usually have more or less conspicuous dark spots laterally; in some specimens there are no spots. Except for the lateral spots (when present) the ventrals are immaculate white. The dorsal ground-color is pale brownish-white, white or pale blue between the 4th and 7th rows of dorsal scales and dorsally between the 7th rows on each side. Stripes are never present on the uniformly pale colored 8th, 9th and vertebral scale-rows.
Usually there are eight supralabials on each side; however, seven of the 27 specimens examined have seven supralabials on each side, and three others have seven on one side, and eight on the other. Never is more than the lower third of the supralabials dark brown. In many specimens little or no brown is on the supralabials. There is little or no brown on the chin.
Variation in coloration and in number of supralabials appears to be of no geographic significance.
Although no juveniles have been collected, I expect that juveniles resemble adults in coloration. Probably there would be a greater contrast between the dark stripes and the pale ground-color in juveniles.
In life an adult from three miles northwest of Lerdo de Tejada, Veracruz, México (UMMZ 114484), had black stripes on the 4th and 7th rows of dorsal scales, and black spots on a brown background on the 1st row. The 2nd row had a medial, pale to medium brown auxiliary stripe on a brownish-white background. Posterior to the nape the 3rd row was medium brown. The area between the 4th and 7th rows and the dorsum between the 7th row of scales on each side was a pale brownish-white. Posterior to the place of scale-reduction the primary stripes were displaced downward by one row to the 3rd and 6th rows and secondary stripes originated as elongated spots on the 4th and 7th rows. Near the tail the secondary stripes were broad and continuous. The head was white or tannish-white with three dark brown or black stripes.
Remarks.—In his diagnosis of C. l. lineatus, Smith (1941:122) states: "lateral dark stripe … very narrow posterior to nape, extending along fourth scale row; posteriorly a stripe along third and eighth (farther posteriorly the seventh) scale rows; a narrow dark stripe along sixth scale row, continuous throughout length of body…." I fail to find a dark stripe on the 6th row throughout the length of the body. In all specimens that I have seen, there is a dark stripe on the 7th row anteriorly and on the 6th row posteriorly. In many specimens the stripes on the 3rd and 8th (posteriorly the 7th) scale-rows are absent or present so far posteriorly that the 8th row is never involved.
The dark brown on the first scale-row and the presence of a lateral dark stripe on the 4th row of dorsal scales only, in combination with the characteristics of the genus, distinguish C. l. lineatus from all other snakes in México.
Distribution.—Semi-arid habitats on the coastal plain of Veracruz, México, from Tecolutla to Lerdo de Tejada and Piedras Negras ([fig. 2]).
Specimens examined.—Total of 27, as follows: México: no specific locality, AMNH 19614-15, 19621-24, 19642-43, NMW 16827. Veracruz: no specific locality, AMNH 19618-20, CAS 73640, NMW 16829; 4 km. S Alvarado, KU 58124; 14 mi. N Alvarado, UIMNH 46978; 6 mi. SE Boca del Río, UIMNH 28023; Etiopa, 2 mi. S Tecolutla, UIMNH 3847; ca. 30 mi. E Jalapa, AMNH 81948; 3 mi. NW Lerdo de Tejada, UMMZ 114484-85; Paso del Macho, USNM 109708; Río Blanco, 20 km. WNW Piedras Negras, KU 23253; Veracruz, AMNH 19612, UF 8990; W side Veracruz, AMNH 19616; 2 mi. W Veracruz, AMNH 19617, 19619.