ACCOUNTS OF THE SPECIES AND SUBSPECIES
Study of Pituophis deppei (auctorum) revealed the presence of sympatric populations of two distinct species of Pituophis differing from each other in scutellation and coloration. The nomenclature resulting from the required rearrangement necessitates the recognition of 1) deppei as a species, 2) jani as a subspecies of deppei, 3) lineaticollis (with brevilineata as a synonym) as a species distinct from deppei, and 4) gibsoni as a subspecies of lineaticollis. Known geographic distributions of these named taxa are shown in [Figure 1].
Pituophis deppei deppei Duméril
Elaphis deppei Duméril, Mem. Acad. Inst. France, vol. 23, p. 453, 1853; Duméril and Bibron, Erpétologie générale, vol. 7, p. 268, February 25, 1854.
Pituophis deppei, Jan, Elenco sistematico degli ofidi, p. 59, 1863; Günther, Biologia Centrali-Americana, Reptilia, p. 124, February, 1894.
Elaphis pleurostictus Duméril, Mem. Acad. Inst. France, vol. 23, p. 453, 1853 [Type.—Museum d'Histoire Naturelle Paris, No. 6616; type locality—"Monte Video" (restricted to San Juan Teotihuacán, México, by Smith and Taylor, 1950: 334)].
Pituophis pleurostictus, Jan, Elenco sistematico degli ofidi, p. 59, 1863.
Pituophis deppei, var. pholidostictus Jan, Elenco sistematico degli ofidi, p. 59, 1863 [Type.—Zoologisches Museum Berlin, No. 1738; type locality.—"Mexico" (restricted to San Juan Teotihuacán, México, by Smith and Taylor, 1950: 334)].
Pituophis deppei deppei, Stull, Occas. Papers Mus. Zool. Univ. Michigan, no. 250, p. 1, October 12, 1932; Bull. U. S. Natl. Mus. 175, p. 25, April 23, 1940; Smith and Taylor, U. S. Natl. Mus., no. 187, p. 107, 1945.
Type.—Rijksmuseum van Natuurlijke Histoire, Leiden, No. ???, obtained by Ferdinand Deppe. The type locality was originally given as "Mexico"; this was restricted to San Juan Teotihuacán, state of México, by Smith and Taylor (1950: 334).
Diagnosis.—This subspecies is characterized by the presence of solid body-blotches and lateral intercalary spots, dorsal interspaces less than five scales in length, and the absence of paired stripes or rows of blotches, on the anterior part of the body. There are 209 to 232 ventrals and 52 to 62 caudals. The body-blotches number 27 to 49. In adults the anterior and posterior body-blotches are black; the lateral intercalary spots are solid black. In many individuals black dashes connect the adjacent corners of the dorsal body-blotches ([Pl. 45, Fig. 1]). In juveniles the anterior, dorsal body-blotches are black, whereas those at the midbody and posteriorly are brown.
Variation.—Geographically, scutellation varies only slightly. Comparison of specimens from the northern part of the Mexican Plateau (Chihuahua, Coahuila, and Durango—5 specimens), the central part of the plateau (Aguascalientes, San Luis Potosí, and Zacatecas—13 specimens), the southern part of the plateau (Guanajuato, Jalisco, México, and Michoacán—18 specimens), and Puebla and southern Veracruz (12 specimens) shows the average number of ventrals for these samples to be, respectively, 221.6, 216.7, 221.3, and 220.0. The average number of dorsal body-blotches for the same samples are, respectively, 36.6, 37.7, 38.4, and 34.6. Only in the southernmost sample is there a noticeable difference in the number of blotches.
The specimen from Párajo Verde, Veracruz, was considered to be an intergrade between P. deppei and P. lineaticollis by Smith (1943: 461), who stated that, although the snake had 231 ventrals and dark lateral streaks as does deppei, it had light-centered dorsal blotches and stripes on the neck as does lineaticollis. This specimen (USNM 110892) has a high number of ventrals for deppei; one from Jalisco has 232, and one each from Guanajuato and Veracruz have 229. The blotches posteriorly are lighter than those anteriorly and are slightly lighter in the center than at the periphery. Two anterior blotches are divided medially and narrowly connected by black streaks. Although these are somewhat suggestive of the pattern of lineaticollis, they are more nearly like that of deppei. Four other specimens from the same area are typically deppei. There is some doubt as to the actual provenance of the snake stated to have come from Párajo Verde, for, according to Smith (1943: 460), the snake had been tied to a truck and dragged halfway down the slopes of the Cumbres de Acultzingo, where he found it. He surmised that it probably was dragged no farther than the settlement, Párajo Verde, at the Cumbres de Acultzingo.
Fugler and Webb (1956: 171) commented on the uniformly brown dorsum of a specimen (KU 39564) from 16 miles east and 18 miles north of Ocampo, Coahuila. It has a higher number of ventrals (242) and caudals (88) than is known for deppei. It is, without a doubt, a Pituophis. It is not Pituophis catenifer, as attested to by the presence of only two prefrontals. The high number of ventrals and caudals, together with the uniform dark brown dorsum, provide a combination of characters indicating that this specimen may represent an undescribed species in the deppei group of Pituophis.
Distribution.—Southern Chihuahua and southern Coahuila southward on the western and central parts of the Mexican Plateau to the Valley of México and to southeastern Puebla and adjacent Veracruz.