I 'LI B RAR.Y OF THE UNIVERSITY OF ILLINOIS 590.5 FI v. 28-29 The person charging this material is re- sponsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN JO THE LIBRARY Of THE MAR 9 1944. UNIVERSITY Of ILLINOIS ZOOLOGICAL SERIES OF FIELD MUSEUM OF NATURAL HISTORY Volume 29 CHICAGO, FEBRUARY 29, 1944 No. 8 SNAKES OF THE HOOGSTRAAL EXPEDITIONS TO NORTHERN MEXICO BY HOB ART M. SMITH DEPARTMENT OF ZOOLOGY, UNIVERSITY OP ROCHESTER During the summers of 1938, 1939, and 1940 parties of students of the University of Illinois under the leadership of Mr. Harry Hoogstraal collected a number of reptiles and amphibians in north- eastern Mexico. These were secured either as an integral part of biological surveys (as in Nuevo Leon) undertaken by Mr. Hoog- straal, or as the party was en route to or from other areas where more intensive work was in progress. The specimens are now incor- porated in the reference collections of Field Museum. This report concerns only the snakes. Although these are not numerous, 23 species are represented among the 53 specimens. Among them is an extraordinary number of very unusual or noteworthy specimens. One new race has already been described and a new species is named herein. Equally as important are notable range extensions of six species, and additional specimens that shed considerable light upon the variation and relationships of three other species. Knowing my interest in Mexican snakes, Mr. Karl P. Schmidt of Field Museum generously suggested that I submit a report on this collection. I am greatly indebted to him and to Mr. Clifford H. Pope, also of Field Museum, for the privilege of doing so. Leptotyphlops dulcis Baird and Girard Reno, dulcis Baird and Girard, Cat. N. Amer. Kept., pt. 1, p. 142, 1853 — between San Pedro and Comanche Springs, Texas. Leptotyphlops dulcis Stejneger, Proc. U. S. Nat. Mus., 14, p. 501, 1891. Hidalgo: Jacala (34412). No. 553 135 NAT. U.OFU.UB, HfST- 136 FIELD MUSEUM OF NATURAL HISTORY— ZOOLOGY, VOL. 29 This specimen extends the known range of dulcis a considerable and unexpected distance of about 300 miles to the south, from central Nuevo Leon to northern Hidalgo. The specimen seems typical, with an undivided first labial (one scale between ocular and rostral); 215 dorsals from rostral to terminal tail spine; 10 rows of scales about base of tail, 14 around body; 15 subcaudal scales; 7 rows of scales pigmented dorsally. This specimen supports the premise that dulcis overlaps myopicus. Leptotyphlops myopicus myopicus Garman Stenostoma myopicum Carman, Mem. Mus. Comp. Zool., 8, p. 6, 1883 — Savi- neto near Tampico, Tamaulipas. Leptotyphlops dulcis myopicus Klauber, Trans. San Diego Soc. Nat. Hist., 9, pp. 117-120, 1940. Nuevo Leon: Ojo de Agua, near Galeana (30615) ; Horsetail Falls, Santiago, 42 miles south of Monterrey (30616-8, 30824). This series, with the exception of No. 30824, was discussed by Klauber (I.e.), who records the entire series as from Ojo de Agua, although the Field Museum catalogue cites only one from that locality, the remainder from Horsetail Falls. This correction does not alter Klauber's statements of relationship, however, except that the view that the incomplete suture between the posterior half of the first supralabial and the ocular in the Ojo de Agua specimen is an aberration becomes inferential. On one side, specimen No. 30824 also has an incomplete suture between the ocular and posterior half of the first supralabial, much as in No. 30615; the dorsal scales from rostral to tip of tail (excluding spine) number 211. As Klauber states, the evidence of intergradation of the species dulcis and myopicus is not wholly convincing; there are a number of facts, such as the broad geographic overlap of dissectus and dulcis and the different geographic trends in variation, that support the conclusion that they are different species. Amastridium sapperi Werner Mimometopon sapperi Werner, Abhandl. Bayer. Akad. Wiss., 22, p. 349, 1903 — Guatemala. Amastridium sapperi Dunn, Proc. U. S. Nat. Mus., 65, Art. 11, p. 1, 1924. Nuevo Leon: Santiago, Hda. Vista Hermosa (37140). The most extraordinary specimen of the collection is this, repre- senting a genus and species not otherwise known north of the Pacific ~l , /y /) 7 , /-/,£ / /, / > , 1944 SNAKES OF NORTHERN MEXICO— SMITH 137 slopes of Chiapas near Guatemala. I have compared it directly with a specimen in the United States National Museum (No. 46509) from Chicharras, Chiapas, and aside from a few very minor differences, due probably to age, there is absolutely nothing to indicate that the two specimens are not the same species. So remarkably alike are they that they could well have come from the same spot, in spite of the fact that about 500 miles and several moderately distinct barriers separate the two localities from which they are recorded. It is not usual to find a widely spread species so remarkably uniform, in localities as remote from each other as these; and for this reason it must be clear that the above record must find corroboration before it can be accepted without question. At the present time, however, there is no concrete evidence that it is not correct. Head of normal size, slightly wider than neck, flattened some- what, not elongate; tip of snout truncate, rostral covering its anterior face; in profile snout slanting somewhat, projecting farther forward dorsally than at labial border. Only upper edge of rostral visible from above, but this involves two-thirds its maximum width; inter- nasals three-fifths size of prefrontals, their median suture nearly as long as that of prefrontals; frontal (4 mm.) longer than its distance from tip of snout (2.5 mm.), about equal to maximum length of parietals (4 mm.), longer than median parietal suture (2.8 mm.), slightly wider than a supraocular; sides of frontal parallel, posterior angle acute (about 80°), anterior edge straight except for a short median projection between prefrontals. Parietals in contact with both postoculars, narrowly separated from fifth supralabial by the first temporal. Nasal entire, with an incomplete suture above and below, anterior section longer but lower than posterior section; naris slightly nearer upper than lower margin of nasal; loreal square, in contact with second supralabial and prefrontal; preocular single, lower half much narrower (longitudinal axis) than upper half; two postoculars, upper twice as large as lower; temporals 1-2-3, anterior in contact with lower postocular. Supralabials 7-7, third and fourth bordering orbit, fifth largest, first smallest, last low and elongate. Infralabials 9-9, the scales of the first pair narrowly in contact medially behind a triangular mental; latter as long as broad; two pairs of elongate chinshields, in contact with five infralabials (first with four, second with two) on each side, anterior slightly broader than but only three-fourths length of posterior. 138 FIELD MUSEUM OF NATURAL HISTORY— ZOOLOGY, VOL. 29 Dorsal scales smooth, pitless, in 17 rows throughout length of body; 163 ventrals; anal divided; subcaudals 78, divided; total length 256 mm., tail 63 mm.; female. Dorsal body color dark brownish gray posteriorly, becoming black anteriorly; edges of all posterior scales and of lateral anterior scales dark, center lighter; ventral surfaces heavily stippled, of about same color (brownish gray) as sides of body, with irregular, scarcely visible, unstippled areas scattered over entire area. On dorsal surface of nape a light area (red in life?) extending three or four scale lengths posterior to parietals, indented medially by a narrow black projection reaching almost to parietals. Top of head brownish, with a light streak extending along the sides of the parietals and through upper postocular to eye; a broad light streak along median parietal suture, bifurcating at frontal and disappearing about halfway to orbit; an irregular light streak on supraocular, near outer edge; pref rentals and internasals with irregular, alter- nating dark and light longitudinal streaks. Sides of head black, except for a small, well-defined light spot in the middle of each of the anterior five supralabials. Gular region, up to a line somewhat above level of rictus oris, and entire ventral surface of head black, except for scattered, distinct light spots or longitudinal streaks, generally near the middle of the scales. The adult male from Chicharras, Chiapas (total length 518 mm., tail 140 mm., extreme tip missing), is practically identical in all respects, except that it has keeled supra-anal scales, 151 ventrals and 85 caudals (incomplete); the sides of the head are dimly streaked. The entire body is uniform gray-brown above, except for a small, distinct, light spot on the middle of every second, third or fourth scale of row 5; in general these spots are most clearly defined posteri- orly, and are very poorly defined on the neck. The Nuevo Leon specimen shows evidence of these dots also, similarly placed, in certain parts of the posterior half of the body. Drymobius margarit if erus margaritiferus Schlegel Herpetodryas margaritiferus Schlegel, Ess. Phys. Serp., 2, p. 184, 1837 — New Orleans, by error; restricted to Vera Cruz, Vera Cruz. Drymobius margaritiferus margaritiferus Bocourt, Miss. Sci. Mex., livr. 12, pp. 716-718, pi. 49, fig. 2, 1890; Smith, Proc. U. S. Nat. Mus., 92, p. 383, 1942. Nuevo Leon: Horsetail Falls, Santiago, 42 miles south of Mon- terrey (30829). 1944 SNAKES OF NORTHERN MEXICO— SMITH 139 A single male is typical; scale rows 17-17-15; ventrals 156; tail incomplete; supralabials 9-9; infralabials 10-10; preoculars 1-1; postoculars 2-2; temporals 2-2. Ficimia olivacea streckeri Taylor Ficimia streckeri Taylor, Copeia, 1931, pp. 5-7, 1931 — three miles east of Rio Grande City, Texas. Hidalgo: Jacala (34413). Nuevo Leon: Horsetail Falls, 42 miles south of Monterrey (30817). Both specimens are females; ventrals 147, 150, caudals 35, 34+, supralabials 7-7, infralabials 7-8, 8-8, preoculars and postoculars 1-1, internasals 0-0, respectively. In the absence of internasals and presence of single postoculars both specimens are typical, but in pattern the Hidalgo specimen tends strongly toward F. olivacea; it is practically unicolor above, with small, dark spots on the mid- dorsal line, spaced two or three scale lengths apart. These spots are the sole remnants of the distinct crossbands of typical streckeri, such as those in the Nuevo Leon specimen, which has 45 bands on body, 11 on tail. It is noteworthy that the Tuxpan, Vera Cruz, specimens also have indistinct dorsal spots; thus the three southern- most specimens of streckeri strongly indicate an intergradation in pattern with olivacea. The only other character conspicuously different in the two forms (number of postoculars) shows no clear evidence of intergradation, but the character is inconstant, at least in olivacea, and thus should perhaps not be considered as denning a distinct species. One olivacea of large size, no dorsal pattern, and no internasals (M.C.Z. 6354) has but one postocular on both sides; conformation of the postoculars and adjacent (fourth) labials is not notably different than in streckeri. In view of these facts it appears best to consider streckeri a subspecies of F. olivacea Gray. Gyalopion canutn Cope Gyalopion canum Cope, Proc. Acad. Nat. Sci. Phila., 12, p. 243, 1860 — Fort Buchanan, Arizona. Nuevo Leon: Galeana (30816). This specimen considerably extends the known range and affords further data on the variation of this rare species. While five females are recorded by Smith and Taylor (1941, p. 362), only two males are included; the present specimen, a male, is therefore of special interest. It has 125 ventrals, 31 caudals, anal divided, 7-7 supralabials and 140 FIELD MUSEUM OF NATURAL HISTORY— ZOOLOGY, VOL. 29 infralabials, 1-1 preoculars, 2-2 postoculars, 1-2 temporals, 1-1 internasals; total length 168 mm., tail 24.5 mm. The spots on the body number 46, on the tail 11. The ventral count of this specimen is four lower than the lowest given by Van Denburgh (129, presumably a male; 1922, p. 778), and nine lower than the males listed by Smith and Taylor (I.e.); yet the total range, 125 to 136, known for all males is not excessive. The number of spots on the body of the Galeana specimen is also five higher than the highest known in other specimens, giving a total range of seventeen for the whole species, yet this difference is scarcely great enough, on the basis of one specimen, to warrant the conclusion that the Galeana specimen represents a different race. Still another male specimen, recently acquired by Field Museum, is of interest. It is No. 30429, from Mount Livermore, Jeff Davis County, Texas, collected by J. M. and R. G. Schmidt in July, 1938. It has 131 ventrals, 34 caudals, 2-2 temporals, 7-8 infralabials, 41 spots on the body and 12 on the tail, and is otherwise like the Galeana specimen. Lampropeltis thayeri Loveridge Lampropeltis thayeri Loveridge, Occ. Papers Bost. Soc. Nat. Hist., 5, pp. 137-138, 1924— Miquihuana, Tamaulipas. Nuevo Leon: Ojo de Agua, near Galeana (30819-21). A choice item of the collection is a series of three young speci- mens of this species, previously known from the single male type. All are females; respectively the scale rows are 21-23-18, 21-22-17, 21-23-18; ventrals 212, 203, 206; caudals 55, 60, 57; supralabials 7-7; infralabials 9-9; preoculars 1-1; postoculars 2-2; temporals 2-2, 2-3, 2-3; total length (in mm.) 280, 255, 248; tail length (in mm.) 42, 44, 40; red bands on body and tail 28 + 7, 26 + 7, 27 + 9. The white bands on the body number the same as the red bands, but on the tail number one more than the red bands. The stomach of one specimen contained a half-grown lizard, Sceloporus grammicus disparilis. The pattern is highly interesting. In two specimens each red band is split medially by a broad, lighter area irregularly bordered by a narrow black line much narrower than the primary black borders of the red bands; the red areas within the red bands are somewhat narrower than the central, lighter area; the lighter area and its dark borders extend laterally no farther than about the fifth or sixth scale rows. In the other specimen the light areas are not 1944 SNAKES OF NORTHERN MEXICO— SMITH 141 evident, although the red bands are fully as broad as in the preceding specimens. The red bands in all specimens narrow greatly laterally, are separated from each other medially by two to two and one-half scale lengths, laterally by five or six; on the belly they are one or two ventrals wide but usually closed off by black areas, so that there is generally but little evidence of a ringed effect; in fact, many of the blotches are broken or actually terminate laterally on the outer feonfs a/ferna mexicona subgroup TRIANGULUM FIG. 18. Diagram of relations in the triangulum group. dorsal scale rows (one to three). The belly is heavily marked with black; many ventrals are black over most of their width, and few are entirely unmarked. As in mexicana, alterna, and leonis, the areas between the red blotches on the body, and most of the head, are heavily stippled with gray; likewise as in these species, there is a black-bordered, median dorsal red area on the head. In these specimens it is not divided and involves most of the frontal and the anterior edges of the parietals. A dark postocular spot is regularly present. These specimens show that thayeri does not belong with the ringed species (pyromelana subgroup) as I recently concluded (1942, p. 206), but rather with the blotched species of the mexicana subgroup. It affords an important link between the mexicana and triangulum sub- 142 FIELD MUSEUM OF NATURAL. HISTORY— ZOOLOGY, VOL. 29 groups, having a pattern intermediate between the ringed one char- acteristic of the Mexican members of the triangulum group, and the blotched one characteristic of other members of the mexicana sub- group. The latter subgroup, in its tendency toward development of dorsal blotches from a primitive ringed pattern, has a close parallel in the northern United States members of the triangulum group, in which the same type of evolution has occurred. Of further interest in thayeri is the clear indication of the manner of multiplication of the red blotches in this subgroup which is by the development of a central, black-edged, light area across the middle of each red band. Expansion of this light area laterally produces two narrow rings or blotches, each "mixed or split with red," as in Lampropeltis alterna. Very possibly by this means also the pattern of more numerous, enlarged blotches in mexicana was produced. The phylogeny of the members of the mexicana subgroup is not entirely clear, although all are rather closely interrelated. L. thayeri is obviously the most primitive of the series, since the belly is heavily mottled, there is a large nuchal blotch, and a large median red area on the head. Conversely, leonis and alterna are the most highly modified. Because the pattern modifications of thayeri readily explain the pattern evolution of alterna, these two are probably directly related; and leonis, which retains broader red blotches at the expense of completely suppressed alternate blotches, appears to be directly related to mexicana, in which the red bands are about twice as numerous as in leonis; the last could have been derived from a mexicana-like ancestor simply by loss of about every other red blotch. Thus alterna and leonis, although closely related, remain as end forms of two different stocks; they parallel each other in the strong tendency toward pattern reduction; they differ from each other somewhat in the manner of the reduction. The most puzzling question at present regarding the mexicana subgroup is as to its origin from and the identity of its closest rela- tive in the triangulum subgroup; at present none appears very closely allied. Leptodeira maculata Hallowell Megalops maculatus Hallowell, Proc. Acad. Nat. Sci. Phila., p. 488, 1860 — Tahiti, in error; probably Nicaragua. Leptodeira maculata Taylor, Kans. Univ. Sci. Bull., 25, pp. 337-342, pi. 31, fig. 1, pi. 32, figs. 1-4, pi. 33, figs. 1-3, text figs. 6-7, 1939. San Luis Potosi: El Pujal (34372). 1944 SNAKES OF NORTHERN MEXICO— SMITH 143 A single female has 21-23-17 scale rows; 173 ventrals; 63 caudals; 8-8 bands on body, 10 on tail; blotches reaching second or third scale row; belly immaculate, not stippled. Leptodeira annulata septentrionalis Kennicott Dipsas septentrionalis Kennicott, in Baird, Rept. Mex. Bound. Surv., 2, p. 16, pi. 8, fig. 11, 1859 — Matamoros, Tamaulipas. Leptodeira annulata septentrionalis Smith, Proc. Biol. Soc. Wash., 54, p. 117, 1941. Nuevo Leon: Los Ad juntos (37030); Ojo de Agua, Sabinas Hidalgo (34418-20); Horsetail Falls, Santiago, 42 miles south of Monterrey (30823). San Luis Potosi: El Bafiito, Valles (37031). Respectively these specimens have 21-21-15, 21-23-16, 21-23- 16, 21-23-16, 21-23-15, 19-21-15 scale rows; ventrals 196, 191, 196, 191, 189, 195; caudals 84 (male), 67, 69 (female), 76, 78, 84 (male); supralabials 8-8; infralabials 10-10; preoculars 3-3; postoculars 2- 2; temporals 1-2-3; bands on body and tail respectively 24-13, 21-11, 27-10, 23-15, 21-12, 29-13; posterior edges of ventrals pig- mented to some extent in all. These six specimens are rather uniform in appearance except for No. 37031, which approaches annulata taylori to some extent; the body bands are more irregular than in the others, tending to fuse with each other and the halves on either side of the body to alternate with each other; and the blotches narrow considerably on the sides, involving only one to five scales (average about three) on the first row and scarcely touching ventrals. In the other specimens they involve from three to eight scales in the first row, and distinctly involve the ends of the ventrals at least posteriorly. These charac- ters, in the Valles specimen, support the belief that septentrionalis and taylori intergrade in the latitude of northern Vera Cruz. Three other specimens, presumably of this race, now missing and not examined by me, were collected: No. 37032 at El Banito, Valles, San Luis Potosi; and Nos. 37028-9 at Santiago, Hda. Vista Hermosa, Nuevo Leon. Leptophis mexicanus mexicanus DumeYil and Bibron Leptophis mexicanus Dumeril and Bibron, Erp. Gen., 7, p. 536, 1854 — Mexico. Leptophis mexicanus mexicanus Bocourt, Miss. Sci. Mex., livr. 15, p. 835, 1897. San Luis Potosi: El Pujal (34371). 144 FIELD MUSEUM OF NATURAL HISTORY— ZOOLOGY, VOL. 29 A female has 15-15-11 scale rows, 172 ventrals, 161 caudals, 8-8 supralabials, 11-11 infralabials, 1-1 preoculars, 2-2 postoculars, 1-2 temporals. This specimen appears to be the first known from the state of San Luis Potosi; it has been recorded somewhat farther north at Tampico, Tamaulipas. Masticophis flngellum testaceus Say Coluber testaceus Say, Long's Exped. Rocky Mts., 2, p. 48, 1823 — headwaters of the Arkansas River, Colorado. Tamaulipas: 21 miles south of Victoria (37138). I have not seen this specimen. Natrix rhombifera rhombifera Hallowell Tropidonottts rhombifer Hallowell, Proc. Acad. Nat. Sci. Phila., 6, p. 177, 1858 — Arkansas River and its tributaries near the northern boundary of the Creek Nation. Natrix rhombifera rhombifera Clay, Ann. Carnegie Mus., 27, pp. 251-253, 1938. Nuevo Leon: Ojo de Agua, near Sabinas Hidalgo (34414-7, 34423-9). In all five of the males the scale rows are 25-25-21, except in one which drops one row near the anus. In the six females, however, three have an extra pair of scale rows at the middle of the body; one of these, and one with 25 rows, drop a single row near the anus, giving a count of 20 at that point. The supralabials are 8-8 in all, the infralabials 12-12; the preoculars are 2-2 in one (34417), while the remainder have 1-1; the fourth labial enters the orbit in all. Variation in various scale characters and in measurements is given in the following table. Number Sex 34414 9 34425 9 34426 9 34427 9 34428 9 34415 d" 34416