Agkistrodon Palisot de Beauvois, 1799—AMERICAN MOCCASINS
A. contortrix (Linnaeus, 1766)—Copperhead
The evolutionary status of the nominal subspecies is unclear and requires work to determine whether they are historical entities.
A. c. contortrix (Linnaeus, 1766)—Southern Copperhead
A. c. laticinctus Gloyd and Conant, 1934—Broad-banded Copperhead
A. c. mokasen Palisot de Beauvois, 1799—Northern Copperhead
A. c. phaeogaster Gloyd, 1969—Osage Copperhead
A. c. pictigaster Gloyd and Conant, 1943—Trans-Pecos Copperhead
A. piscivorus (Lacepède, 1789)—Cottonmouth
A detailed study of geographic variation in this species should provide interesting marks of history, particularly because the Mobile Bay Embayment, a critical biogeographic barrier, seems to be involved in morphological differentiation.
A. p. conanti Gloyd, 1969—Florida Cottonmouth
A. p. leucostoma (Troost, 1836)—Western Cottonmouth
A. p. piscivorus (Lacepède, 1789)—Eastern Cottonmouth

Arizona Kennicott, 1859—GLOSSY SNAKES
Collins (1991, Herpetol. Rev. 22: 42–43) elevated Arizona elegans occidentalis to specific status to include all populations in the Sonoran and Mohave Desert region. This arrangement was followed by Liner (1994, SSAR Herpetol. Circ. 23) and Collins (1997, SSAR Herpetol. Circ. 25). Collins (1991, Herpetol. Rev. 22: 42–43) was the first use of this binomial. Because no discussion of the taxonomic diagnosis was presented (although Dixon [1959, Southwest. Nat. 4: 20–29] found tail length differences between eastern and western groups), we retain occidentalis as a nominal subspecies, even though we suspect that detailed study of geographic variation might support Collins’ assertion.
A. elegans Kennicott, 1859—Glossy Snake
Reviewed by Dixon and Fleet (1976, Cat. Am. Amph. Rept. 179).
A. e. arenicola Dixon, 1960—Texas Glossy Snake
A. e. candida Klauber, 1946—Mojave Glossy Snake
A. e. eburnata Klauber, 1946—Desert Glossy Snake
A. e. elegans Kennicott, 1859—Kansas Glossy Snake
A. e. noctivaga Klauber, 1946—Arizona Glossy Snake
A. e. occidentalis Blanchard, 1924—California Glossy Snake
A. e. philipi Klauber, 1946—Painted Desert Glossy Snake

Bogertophis Dowling and Price, 1988—DESERT RATSNAKES
Schulz (1996, A Monograph of the Colubrid Snakes of the Genus Elaphe Fitzinger, Koeltz Scientific Books) applied the generic name Elaphe to this genus due to his opinion that the genus Elaphe is in need of an overall revision, but not because Schulz disagreed with Dowling and Price (1988, The Snake, 20: 52–63). We concur that Elaphe is in need of systematic revision globally, but retain Bogertophis because it is a demonstrably monophyletic group (Dowling, 1957, Occ. Papers Mus. Zool. Univ. Michigan 583: 1–22) which Elaphe (sensu lato) definitely is not. Further, Keogh (1996, Herpetologica 52: 406–416) found Bogertophis to be more closely related to other Lampropeltini than to other Elaphe.
B. rosaliae (Mocquard, 1899)—Baja California Ratsnake
Reviewed by Price (1990, Cat. Am. Amph. Rept. 498).
B. subocularis (Brown, 1901)—Trans-Pecos Ratsnake
Reviewed by Worthington (1980, Cat. Am. Amph. Rept. 268).
B. s. subocularis (Brown, 1901)—Trans-Pecos Ratsnake

Carphophis Gervais, 1843—WORMSNAKES
C. amoenus (Say, 1825)—Eastern Wormsnake
C. a. amoenus (Say, 1825)—Eastern Wormsnake
C. a. helenae (Kennicott, 1859)—Midwestern Wormsnake
C. vermis (Kennicott, 1859)—Western Wormsnake
Clark (1968, Herpetologica 24: 104–112) recommended elevation of vermis to species status on the basis of allopatry and morphology, but Rossman (1973, J. Herpetol. 7: 140–141) presented evidence in the form of intergrade populations for the conspecificity of amoenus and vermis. Collins (1991, Herpetol. Rev. 22: 42–43) considered C. vermis to be distinct from C. amoenus, the implication being that the intermediate (and isolated) population discussed by Rossman was either considered the most plesiomorphic members of C. vermis, or an unnamed taxon.

Cemophora Cope, 1860—SCARLETSNAKES
The existence of C. c. coccinea on either side of the Mississippi embayment, likely with no mutual gene flow, suggests to us that a detailed study of geographic variation would produce considerable taxonomic change.
C. coccinea (Blumenbach, 1788)—Scarletsnake
Reviewed by Williams (1985, Cat. Am. Amph. Rept. 374).
C. c. coccinea (Blumenbach, 1788)—Florida Scarletsnake
C. c. copei Jan, 1863—Northern Scarletsnake
C. c. lineri Williams, Brown, and Wilson, 1966—Texas Scarletsnake

Charina (Gray 1849)—RUBBER BOAS
Kluge (1993, Zool. J. Linnaean Soc. 107: 293–351) placed Lichanura in the synonymy of Charina because they formed monotypic sister taxa. Given that Kluge did not include fossil erycine taxa in his study, his conclusion of monotypic sister taxa may be premature. In addition, recent phylogeographic studies suggest that the two genera may not be monospecific (see Rodriguez-Robles et al. 2000, ASIH-HL-SSAR abstracts for Charina; Wood, 2000 ASIH-HL-SSAR abstracts for Lichanura), which preclude combining. As such, we continue to recognize both Charina and Lichanura.
C. bottae (Blainville, 1835)—Rubber Boa
Reviewed by Stewart (1977, Cat. Am. Amph. Rept. 205).
C. b. bottae (Blainville, 1835)—Northern Rubber Boa
C. b. umbratica Klauber, 1943—Southern Rubber Boa
Chilomeniscus Cope, 1860—SANDSNAKES
C. cinctus Cope, 1861—Banded Sandsnake
Wong (Herpetologica, in press) synonymized C. cinctus with C. stramineus Cope 1860, in which case the standard English name "Variable Sandsnake" will be recommended.
Chionactis Cope, 1860—SHOVEL-NOSED SNAKES
C. occipitalis (Hallowell, 1854)—Western Shovel-nosed Snake
C. o. annulata (Baird, 1859)—Colorado Desert Shovel-nosed Snake
There is some question as to the validity of the name Chionactis saxatilis (Funk, 1967, Southwest. Nat. 12: 180), the Gila Mountains Shovel-nosed Snake; generally considered to be a synonym of C. o. annulata (see John Cross, 1978, Ph.D. dissertation, Univ. Arizona).
C. o. klauberi (Stickel, 1941)—Tucson Shovel-nosed Snake
C. o. occipitalis (Hallowell, 1854)—Mojave Shovel-nosed Snake
C. o. talpina Klauber, 1951—Nevada Shovel-nosed Snake
C. palarostris (Klauber, 1937)—Sonoran Shovel-nosed Snake
C. p. organica Klauber, 1951—Organ Pipe Shovel-nosed Snake

Clonophis Cope, 1889—KIRTLAND’S SNAKES
C. kirtlandii (Kennicott, 1856)—Kirtland’s Snake
Reviewed by Rossman and Powell (1985, Cat. Am. Amph. Rept. 364).

Coluber Linnaeus, 1758—NORTH AMERICAN RACERS
The genus Coluber, as currently recognized, is found in the Old World as well as the New World. Anderson (1996, MS thesis, Southeastern Louisiana Univ.) demonstrated that the genus is not monophyletic. Because the type of Coluber is constrictor, we use the English name North American Racers in anticipation of verification of the monophyly of New World taxa.
C. constrictor Linnaeus, 1758—Eastern Racer
Reviewed by Wilson (1978, Cat. Am. Amph. Rept. 218). Fitch et al. (1981, Trans. Kansas Acad. Sci. 84: 196–203) argued for the elevation of C. c. mormon. This recommendation was rejected by Greene (1983, J. Herpetol. 18: 210–211). Greene’s rejection of C. mormon was supported by Corn and Bury (1986, Herpetologica 42: 258–264) who showed that a broad zone of intergradation exists across Colorado and Utah. Collins (1991, Herpetol. Rev. 22: 42–43) re-elevated mormon to specific status, although allopatry was not suitably demonstrated. Anderson (1996, MS thesis, Southeastern Louisiana Univ.) argued that based on allozyme data C. c. mormon cannot be differentiated but that C. c. paludicola and C. c. oaxaca were diagnosable and should be elevated to species status. We retain C. c. mormon and await action on oaxaca and paludicola until the data are published.
C. c. anthicus (Cope, 1862)—Buttermilk Racer
C. c. constrictor Linnaeus, 1758—Northern Black Racer
C. c. etheridgei Wilson, 1970—Tan Racer
C. c. flaviventris Say, 1823—Eastern Yellow-bellied Racer
C. c. foxii (Baird and Girard, 1853)—Blue Racer
C. c. helvigularis Auffenberg, 1955—Brown-chinned Racer
C. c. latrunculus Wilson, 1970—Black-masked Racer
C. c. mormon Baird and Girard, 1852—Western Yellow-bellied Racer
C. c. oaxaca (Jan, 1863)—Mexican Racer
C. c. paludicola Auffenberg and Babbitt, 1953—Everglades Racer
C. c. priapus Dunn and Wood, 1939—Southern Black Racer

Coniophanes Hallowell, 1860—BLACK-STRIPED SNAKES
C. imperialis (Baird and Girard, 1859)—Regal Black-striped Snake
C. i. imperialis (Baird and Girard, 1859)—Tamaulipan Black-striped Snake

Contia Baird and Girard, 1853—SHARP-TAILED SNAKES
C. tenuis (Baird and Girard, 1852)—Sharp-tailed Snake
Reviewed by Leonard and Ovaska (1998, Cat. Am. Amph. Rept. 677). An ongoing study has revealed that C. tenuis may actually consist of two genetically and morphologically distinct species (Chris Feldman, pers. comm.).

Crotalus Linnaeus, 1758—RATTLESNAKES
The traditional view of rattlesnake taxonomy that recognizes two monophyletic sister genera (e.g. Brattstrom, 1964, San Diego Soc. Nat. Hist. 13: 185–268), Crotalus and Sistrurus, has been challenged. Stille (1987, Herpetologica 43: 98–104) and McCranie (1989, Herpetologica 44: 123–126) presented data that suggested Sistrurus is not monophyletic and rendered Crotalus paraphyletic. Parkinson (1999, Copeia 1999: 576–586) found Sistrurus monophyletic but its position rendered Crotalus paraphyletic. Knight et al. (1993, Syst. Biol. 42: 356–367) used mtDNA to defend the traditional generic taxonomy, but in order to do so they had to ignore the most parsimonious tree. We consider the status of Sistrurus unsettled and retain the traditional taxonomy.
C. adamanteus Palisot de Beauvois, 1799—Eastern Diamond-backed
Rattlesnake
Reviewed by McCranie (1980, Cat. Am. Amph. Rept. 252).
C. atrox Baird and Girard, 1853—Western Diamond-backed Rattlesnake
C. cerastes Hallowell, 1854—Sidewinder
The status of the subspecies is dubious, most likely being artifacts of continuous variation, although the Colorado River as a barrier to gene flow should not be underestimated.
C. c. cerastes Hallowell, 1854—Mojave Desert Sidewinder
C. c. cercobombus Savage and Cliff, 1953—Sonoran Sidewinder
C. c. laterorepens Klauber, 1944—Colorado Desert Sidewinder
C. exsul Garman, 1883—Red Diamond Rattlesnake
Grismer et al. (1994, Bull. So. California Acad. Sci. 93: 45–80) synonymized Crotalus ruber with C. exsul. However, there is a petition to conserve the name ruber. Until the formal petition is acted upon, we follow Grismer et al (op.cit.).
C. e. exsul Garman, 1883—Peninsular Red Diamond Rattlesnake
C. horridus Linnaeus, 1758—Timber Rattlesnake
Pisani et al. (1972, Trans. Kansas Acad. Sci. 75: 255–263) conducted a multivariate analysis of variation in Crotalus horridus and concluded that characters tended to be clinal and recommended against recognition of the two subspecies. Brown and Ernst (1986, Brimleyana 12: 57–74) countered that morphology in the eastern part of the range supported recognition of coastal plain and montane subspecies. Reviewed by Collins and Knight (1980, Cat. Am. Amph. Rept. 253).
C. lepidus (Kennicott, 1861)—Rock Rattlesnake
C. l. klauberi Gloyd, 1936—Banded Rock Rattlesnake
C. l. lepidus (Kennicott, 1861)—Mottled Rock Rattlesnake
C. mitchellii (Cope, 1861)—Speckled Rattlesnake
Reviewed by McCrystal and McCoid (1986, Cat. Am. Amph. Rept. 388).
C. m. pyrrhus (Cope, 1866)—Southwestern Speckled Rattlesnake
C. m. stephensi Klauber, 1930—Panamint Rattlesnake
The relationship of this nominal race to Crotalus viridis in the Southern Great Basin area needs investigation.
C. molossus Baird and Girard, 1853—Black-tailed Rattlesnake
Reviewed by Price (1980, Cat. Am. Amph. Rept. 242).
C. m. molossus Baird and Girard, 1853—Northern Black-tailed Rattlesnake
C. pricei Van Denburgh, 1895—Twin-spotted Rattlesnake
The status of the two widely allopatric subspecies (one extralimital) requires reevaluation. Reviewed by McCranie (1980, Cat. Am. Amph. Rept. 266).
C. p. pricei Van Denburgh, 1895—Western Twin-spotted Rattlesnake
C. scutulatus (Kennicott, 1861)—Mojave Rattlesnake
Evaluation is necessary of the relationship of the nominal race with its extralimital subspecies. Whether they are actually parts of a single lineage is doubtful. Reviewed by Price (1982, Cat. Am. Amph. Rept. 291).
C. s. scutulatus (Kennicott, 1861)—Mojave Green Rattlesnake
C. tigris Kennicott, 1859—Tiger Rattlesnake
C. viridis (Rafinesque, 1818)—Western Rattlesnake
C. v. abyssus Klauber, 1930—Grand Canyon Rattlesnake
C. v. cerberus (Coues, 1875)—Arizona Black Rattlesnake
C. v. concolor Woodbury, 1929—Midget Faded Rattlesnake
C. v. helleri Meek, 1905—Southern Pacific Rattlesnake
C. v. lutosus Klauber, 1930—Great Basin Rattlesnake
C. v. nuntius Klauber, 1935—Hopi Rattlesnake
C. v. oreganus Holbrook, 1840—Northern Pacific Rattlesnake
C. v. viridis (Rafinesque, 1818)—Prairie Rattlesnake
C. willardi Meek, 1905—Ridge-nosed Rattlesnake
C. w. obscurus Harris and Simmons, 1976—New Mexico Ridge-nosed Rattlesnake
C. w. willardi Meek, 1905—Arizona Ridge-nosed Rattlesnake

Diadophis Baird and Girard, 1853—RING-NECKED SNAKES
D. punctatus (Linnaeus, 1766)—Ring-necked Snake
Evidence to synonymize the various races into a single species has been poorly presented, although our arrangement follows current wisdom here. In particular, the sympatry of Diadophis punctatus regalis and D. p. arnyi suggests that more than one lineage exists (Gehlbach, 1974, Herpetologica 30: 140–148). Pinou et al. (1995, J. Herpetol. 29: 105–110) presented immunological distance data from serum albumin that indicated the presence of genetic divergence and perhaps species level differentiation between edwardsii and the other subspecies, except punctatus. These data appear to support the conclusion reached by Blanchard (1942, Bull. Chicago Acad. Sci. 7: 1–144) over fifty years ago that Diadophis is not monotypic in the United States. Although such differentiation probably exists, elevation of taxa is premature in the absence of a character-based phylogeny. An ongoing molecular genetics project has found the subspecies in California (amabilis, modestus, occidentalis, pulchellus, similis, and vandenburghii) to be nearly indistinguishable, and they probably do not represent unique evolutionary lineages (Chris Feldman, pers. comm.).
D. p. acricus Paulson, 1966—Key Ring-necked Snake
D. p. amabilis Baird and Girard, 1853—Pacific Ring-necked Snake
D. p. arnyi Kennicott, 1859—Prairie Ring-necked Snake
D. p. edwardsii (Merrem, 1820)—Northern Ring-necked Snake
D. p. modestus Bocourt, 1866—San Bernardino Ring-necked Snake
D. p. occidentalis Blanchard, 1923—Northwestern Ring-necked Snake
D. p. pulchellus Baird and Girard, 1853—Coral-bellied Ring-necked
Snake
D. p. punctatus (Linnaeus, 1766)—Southern Ring-necked Snake
D. p. regalis Baird and Girard, 1853—Regal Ring-necked Snake
D. p. similis Blanchard, 1923—San Diego Ring-necked Snake
D. p. stictogenys Cope, 1860—Mississippi Ring-necked Snake
D. p. vandenburghii Blanchard, 1923—Monterey Ring-necked Snake

Drymarchon Fitzinger, 1843—INDIGO SNAKES
D. corais (Boie, 1827)—Western Indigo Snake
Reviewed by McCranie (1980, Cat. Am. Amph. Rept. 267; includes D. couperi).
D. c. erebennus (Cope, 1860)—Texas Indigo Snake
D. couperi (Holbrook, 1842)—Eastern Indigo Snake
Collins (1991, Herpetol. Rev. 22: 42–43) elevated this lineage to specific status based on allopatry and diagnosibility. Whether the diagnosibility of this taxon holds up against rigorous scrutiny across the distribution of Drymarchon is open to testing.

Drymobius Fitzinger, 1843—NEOTROPICAL RACERS D. margaritiferus (Schlegel, 1837)—Speckled Racer
Reviewed by Wilson (1974, Cat. Am. Amph. Rept. 172).
D. m. margaritiferus (Schlegel, 1837)—Northern Speckled Racer

Elaphe Fitzinger, 1833—RATSNAKES
See comments on Bogertophis and Senticolis.
E. bairdi (Yarrow, 1880)—Baird’s Ratsnake
E. gloydi Conant, 1940—Eastern Foxsnake
Collins (1991, Herpetol. Rev. 22: 42–43) elevated gloydi to specific status due its geographic disjunction from vulpina and the characters noted by Conant (1940, Herpetologica 2: 2). Harding (1997, Amphibians and Reptiles of the Great Lakes Region, Univ. Michigan Press) followed Collins (op. cit.), with additional justification that the two taxa occupy very different ecological niches. Additional data are needed to test the hypothesis of divergence between these populations, but in the meantime we follow Collins (op. cit.) and Harding (op. cit.).
E. guttata (Linnaeus, 1766)—Cornsnake
E. g. emoryi (Baird and Girard, 1853)—Great Plains Ratsnake
Vaughan et al. (1996, Texas J. Sci. 48: 175–190) considered E. emoryi and E. guttata conspecific, although their data indicate distributional, morphological, and ecological allopatry between the two, with the possible exception of two specimens from the hiatus.
E. g. guttata (Linnaeus, 1766)—Cornsnake
E. g. meahllmorum Smith, Chiszar, Staley, and Tepedelen, 1994—
Southwestern Ratsnake
E. obsoleta (Say, 1823)—Eastern Ratsnake
Frank Burbrink (in press) shows that Elaphe obsoleta comprises three distinct lineages (3 species proposed by Burbrink) that do not correspond with currently recognized
subspecies.
E. o. lindheimeri (Baird and Girard, 1853)—Texas Ratsnake
E. o. obsoleta (Say, 1823)—Black Ratsnake
E. o. quadrivittata (Holbrook, 1836)—Yellow Ratsnake
E. o. rossalleni Neill, 1949—Everglades Ratsnake
E. o. spiloides (Duméril, Bibron, and Duméril, 1854)—Gray Ratsnake
E. vulpina (Baird and Girard, 1853)—Western Foxsnake
See comment under E. gloydi. Reviewed by Powell (1990, Cat. Am. Amph. Rept. 470; includes E. gloydi).

Farancia Gray, 1842—MUDSNAKES
F. abacura (Holbrook, 1836)—Red-bellied Mudsnake
Reviewed by McDaniel and Karges (1983, Cat. Am. Amph. Rept. 314). Cundall and Rossman (1984, Herpetologica 40: 388–405) presented compelling skull data that indicated substantial divergence between F. a. abacura and F. a. reinwardtii.
F. a. abacura (Holbrook, 1836)—Eastern Mudsnake
F. a. reinwardtii (Schlegel, 1837)—Western Mudsnake
F. erytrogramma (Palisot de Beauvois, 1801)—Rainbow Snake
Reviewed by Mitchell (1982, Cat. Am. Amph. Rept. 293).
F. e. erytrogramma (Palisot de Beauvois, 1801)—Common Rainbow
Snake
F. e. seminola Neill, 1964—Southern Florida Rainbow Snake

Ficimia Gray, 1849—EASTERN HOOK-NOSED SNAKES
The previous Standard English names for Ficimia and Gyalopion made little distributional sense. All are distributed in Mexico, but Ficimia had the moniker "Mexican" whereas Gyalopion had the name "Plateau" yet is clearly not confined to any plateau. Given that Ficimia has the easternmost distribution, we call it "Eastern" and call Gyalopion "Western."
F. streckeri Taylor, 1931—Tamaulipan Hook-nosed Snake
Reviewed by Hardy (1976, Cat. Am. Amph. Rept. 181).

Gyalopion Cope, 1861—WESTERN HOOK-NOSED SNAKES
See note on Ficimia. Reviewed by Hardy (1976, Cat. Am. Amph. Rept. 182).
G. canum Cope, 1861—Chihuahuan Hook-nosed Snake
G. quadrangulare (Günther, 1893)—Thornscrub Hook-nosed Snake

Heterodon Latreille, 1801—NORTH AMERICAN HOG-NOSED SNAKES
H. nasicus Baird and Girard, 1852—Western Hog-nosed Snake
The nominal races in H. nasicus undoubtedly represent arbitrarily delimited sections of continuous variation (Edgren, 1952, Nat. Hist. Misc. No. 112), but this should be confirmed by careful scrutiny. Reviewed by Walley and Eckerman (1998, Cat. Am. Amph. Rept. 698).
H. n. gloydi Edgren, 1952—Dusty Hog-nosed Snake
H. n. kennerlyi Kennicott, 1860—Mexican Hog-nosed Snake
H. n. nasicus Baird and Girard, 1852—Plains Hog-nosed Snake
H. platirhinos Latreille, 1801—Eastern Hog-nosed Snake
Reviewed by Blem (1981, Cat. Am. Amph. Rept. 282).
H. simus (Linnaeus, 1766)—Southern Hog-nosed Snake
Reviewed by Meylan (1985, Cat. Am. Amph. Rept. 375).

Hypsiglena Cope, 1860—FANGLESS NIGHTSNAKES
Taxonomy of Hypsiglena has received some critical review since Tanner’s revision of the genus (1945, Great Basin Nat. 5: 25–92). Dixon (1965, Southwest. Nat. 10: 125–131) and Dixon and Dean (1986, Southwest. Nat. 31: 307–318) studied a morphological contact zone between northern and southern taxa in Sinaloa, finding that it comprised a narrow zone of hybridization with some taxon sympatry. Although they (Dixon and Dean, op. cit.) were hesitant to recommend species-level status for the northern populations (which Dixon originally did in his 1965 paper), we feel that the data therein recommend such a conclusion. Dixon (pers. comm.) agrees, although he would like to obtain molecular genetic data to test this hypothesis. Having said that, Hardy and McDiarmid (1969, Univ. Kansas Pub. Mus. Nat. Hist. 18: 39–252) examined specimens across the range of presumptive contact and elsewhere in western Mexico and conlcuded that no characters existed to separate torquata and ochrorhynchus, except maybe nuchal patterns, which they decided (p. 170) was "a case of pattern dimorphism in a single, otherwise uniform, species." Also, if there are two species, with torquata the southern taxon, evidence is yet to show that torquata is not representative of any northern populations. Grismer et al. (1994, Bull. So. California Acad. Sci. 93: 45–80) dismissed Baja California subspecies of Hypsiglena, stating, without evidence, that the subspecies intergrade widely. We await a detailed analysis of variation in Hypsiglena before discarding subspecies.
H. torquata (Günther, 1860)—Nightsnake
H. t. chlorophaea Cope, 1860—Sonoran Nightsnake
Tanner (1985, Great Basin Nat. 45: 615–676) restricted the subspecies ochrorhyncha to the Cape Region of Baja California, resurrecting chlorophaea for the remaining mainland (including U.S.) populations.
H. t. deserticola Tanner, 1944—Desert Nightsnake
H. t. janii (Dugès, 1865)—Texas Nightsnake
H. t. loreala Tanner, 1944—Mesa Verde Nightsnake
H. t. nuchalata Tanner, 1943—California Nightsnake

Lampropeltis Fitzinger, 1843—KINGSNAKES
The specific and infraspecific variation within this genus remains uncertain. While Keogh (1996, Herpetologica 52: 406–416) could separate the tri-colored and the bi-colored taxa, he could not distinguish among Lampropeltis pyromelana, L. triangulum, and L. zonata.
L. alterna (Brown, 1901)—Gray-banded Kingsnake
Reviewed by Gehlbach (1967, Cat. Am. Amph. Rept. 55). Garstka (1982, Breviora 466: 1–35) was the last reviewer of the mexicana species group of Lampropeltis, but because of intergradation between the whole mexicana group and L. pyromelana, few workers have followed him. Hilken and Schlepper (1998, Salamandra 34: 97–124) provide data to support recognition of L. alterna alterna and L. a. blairi.
L. a. alterna (Brown, 1901)—Gray-banded Kingsnake
L. a. blairi Flury, 1950—Blair’s Kingsnake
L. calligaster (Harlan, 1827)—Yellow-bellied Kingsnake
Reviewed by Blaney (1979, Cat. Am. Amph. Rept. 229).
L. c. calligaster (Harlan, 1827)—Prairie Kingsnake
L. c. occipitolineata Price, 1987—South Florida Mole Kingsnake
L. c. rhombomaculata (Holbrook, 1840)—Mole Kingsnake
L. getula (Linnaeus, 1766)—Common Kingsnake
Blaney (1977, Tulane Stud. Zool. Bot. 19: 47–103) formulated the subspecific taxonomy of Lampropeltis getula, noting three clusters of seemingly smoothly intergrading subspecies: (1) californiae; (2) nigrita - splendida - holbrooki - niger; (3) getula - floridana. Contact between 2 and 3 is extremely narrow and may constitute a species boundary. The intergrade zone between 1 and 2 is considerably wider, but may also constitute a leaky species boundary. The status of L. g. sticticeps (Barbour and Engels, 1942, Proc. New England Zool. Club 20: 101–104) is problematic. Blaney (1977, Tulane Stud. Zool. Bot. 19: 47–103) and Palmer and Braswell (1995, Reptiles of North Carolina, Univ. North Carolina Press) argue that it is indistinguishable from the nominate race, but Lazell and Musick (1973, Copeia 1973: 497–503) considered it distinct due to a suite of morphological characters. Additional work is needed to augment our understanding of these snakes.
L. g. californiae (Blainville, 1835)—California Kingsnake
L. g. floridana Blanchard, 1919—Florida Kingsnake
L. g. getula (Linnaeus, 1766)—Eastern Kingsnake
L. g. holbrooki Stejneger, 1902—Speckled Kingsnake
L. g. nigra (Yarrow, 1882)—Eastern Black Kingsnake
L. g. nigrita Zweifel and Norris, 1955—Western Black Kingsnake
L. g. splendida (Baird and Girard, 1853)—Desert Kingsnake
L. pyromelana (Cope, 1867)—Sonoran Mountain Kingsnake
Reviewed by Tanner (1983, Cat. Am. Amph. Rept. 342). Van Devender et al. (1992, Herpetol. Rev. 23: 10–13) recommended recognition of infralabialis but not woodini, which they considered a junior synonym of Lampropeltis p. pyromelana.
L. p. infralabialis Tanner, 1953—Utah mountain Kingsnake
L. p. pyromelana (Cope, 1867)—Arizona Mountain Kingsnake
L. triangulum (Lacepède, 1788)—Milksnake
The extensive range and geographic variation documented in this species certainly warrants further analysis. Reviewed by Williams (1994, Cat. Am. Amph. Rept. 594).
L. t. amaura Cope, 1860—Louisiana Milksnake
L. t. annulata Kennicott, 1860—Mexican Milksnake
L. t. celaenops Stejneger, 1902—New Mexico Milksnake
L. t. elapsoides (Holbrook, 1838)—Scarlet Kingsnake
L. t. gentilis (Baird and Girard, 1853)—Central Plains Milksnake
L. t. multistriata Kennicott, 1860—Pale Milksnake
L. t. syspila (Cope, 1888)—Red Milksnake
L. t. taylori Tanner and Loomis, 1957—Utah Milksnake
L. t. triangulum (Lacépède, 1788)—Eastern Milksnake
L. zonata (Lockington in Blainville, 1876)—California Mountain Kingsnake
Reviewed by Zweifel (1974, Cat. Am. Amph. Rept. 174). Although Collins (1991, Herpetol. Rev. 22: 42–43) recognized some of the races as distinct species, the diagnosibility of these taxa is arguable. But, it has been suggested that a morphological study would easily diagnose the races as unique lineages (Darrel Frost, pers. comm.).
L. z. multicincta (Yarrow, 1882)—Sierra Mountain Kingsnake
L. z. multifasciata (Bocourt, 1886)—Coast Mountain Kingsnake
L. z. parvirubra Zweifel, 1952—San Bernardino Mountain Kingsnake
L. z. pulchra Zweifel, 1952—San Diego Mountain Kingsnake
L. z. zonata (Lockington in Blainville, 1876)—St. Helena Mountain
Kingsnake



Leptodeira Fitzinger, 1843—CAT-EYED SNAKES
L. septentrionalis (Kennicott, 1859)—Cat-eyed Snake
L. s. septentrionalis (Kennicott, 1859)—Northern Cat-eyed Snake

Leptotyphlops Fitzinger, 1843—THREADSNAKES
Because the morphology in Leptotyphlops is highly constrained, molecular analysis across the geographic range of the species might reveal the existence of cryptic species.
L. dulcis (Baird and Girard, 1853)—Plains Threadsnake
Reviewed by Hahn (1979, Cat. Am. Amph. Rept. 231).
L. d. dissectus (Cope, 1896)—New Mexico Threadsnake
L. d. dulcis (Baird and Girard, 1853)—Texas Threadsnake
L. humilis (Baird and Girard, 1853)—Western Threadsnake
Reviewed by Hahn (1979, Cat. Am. Amph. Rept. 232).
L. h. cahuilae Klauber, 1931—Desert Threadsnake
L. h. humilis (Baird and Girard, 1853)—Southwestern Threadsnake
L. h. segregus Klauber, 1939—Trans-Pecos Threadsnake
L. h. utahensis Tanner, 1938—Utah Threadsnake

Lichanura Cope, 1861—ROSY BOAS
L. trivirgata Cope, 1861—Rosy Boa
The status of the three subspecies in the U.S. (and additional extralimital taxa) is unclear. Spiteri (1988, Southwest. Herpetol. Soc. Spec. Pub. 4: 113–130) reevaluated subspecies within Lichanura trivirgata using morphological data, resulting in an arrangement of subspecies different from that listed below. Spiteri’s taxonomic arrangement has largely been ignored except in pet hobbyist literature and is not followed here. Reviewed by Yingling (1982, Cat. Am. Amph. Rept. 294).
L. t. gracia Klauber, 1931—Desert Rosy Boa
L. t. roseofusca Cope, 1868—Coastal Rosy Boa
L. t. trivirgata Cope, 1861—Mexican Rosy Boa

Masticophis Baird and Girard, 1853—WHIPSNAKES
M. bilineatus Jan, 1863—Sonoran Whipsnake
Contrary to Collins (1997, SSAR Herpetol. Circ. 25), Camper and Dixon (1994, Ann. Carnegie Mus. Nat. Hist. 63: 1–48) did not recognize any subspecies for Masticophis bilineatus. Reviewed by Grismer (1997, Cat. Am. Amph. Rept. 637).
M. flagellum (Shaw, 1802)—Coachwhip
The status of the subspecies with respect to continuous variation or discoverable lineages is unclear. The distribution of Masticophis f. flagellum on both sides of the Mississippi River suggests to us that its diagnosis may be pervasively plesiomorphic. Reviewed by Wilson (1973, Cat. Am. Amph. Rept. 145).
M. f. cingulum Lowe and Woodin, 1954—Sonoran Coachwhip
M. f. flagellum (Shaw, 1802)—Eastern Coachwhip
M. f. fuliginosus (Cope, 1895)—Baja California Coachwhip
Grismer (1994, Herp. Nat. Hist. 2: 82) pointed out evidence that strongly recommended that fuliginosus be considered a separate species and his analysis is in the process doing it now (Lee Grismer, pers. comm.).
M. f. lineatulus Smith, 1941—Lined Coachwhip
M. f. piceus (Cope, 1892)—Red Racer
M. f. ruddocki Brattstrom and Warren, 1953—San Joaquin Coachwhip
M. f. testaceus (Say, 1823)—Western Coachwhip
M. lateralis (Hallowell, 1853)—Striped Racer
Reveiwed by Jennings (1983, Cat. Am. Amph. Rept. 343).
M. l. euryxanthus Riemer, 1954—Alameda Striped Racer
M. l. lateralis (Hallowell, 1853)—California Striped Racer
M. schotti Baird and Girard, 1853—Schott’s Whipsnake
Camper and Dixon (1994, Ann. Carnegie Mus. Nat. Hist. 63: 1–48) elevated schotti and ruthveni from the status as races of Masticophis taeniatus. Reviewed by Camper (1997, Cat. Am. Amph. Rept. 638).
M. s. ruthveni Ortenburger, 1923—Ruthven’s Whipsnake
M. s. schotti Baird and Girard, 1853—Schot’s Whipsnake
M. taeniatus (Hallowell, 1852)—Striped Whipsnake
Reviewed by Parker (1982, Cat. Am. Amph. Rept. 304; includes M. schotti) and more recently by Camper (1997, Cat. Am. Amph. Rept. 639).
M. t. ornatus Baird and Girard, 1853—Central Texas Whipsnake
M. t. taeniatus (Hallowell, 1852)—Desert Striped Whipsnake

Micruroides Schmidt, 1928—SONORAN CORALSNAKES
Reviewed by Roze (1974, Cat. Am. Amph. Rept. 163). Slowinski (1995, J. Herpetol. 29: 325–338) presented morphological and biochemical data supporting separation of the genera Micrurus and Micruroides.
M. euryxanthus (Kennicott, 1860)—Sonoran Coralsnake
M. e. euryxanthus (Kennicott, 1860)—Arizona Coralsnake

Micrurus Wagler, 1824—AMERICAN CORALSNAKES
M. fulvius (Linnaeus, 1766)—Harlequin Coralsnake
Reviewed by Roze and Tilger (1983, Cat. Am. Amph. Rept. 316).
M. tener (Baird and Girard, 1853)—Texas Coralsnake
Collins (1991, Herpetol. Rev. 22: 42–43) elevated Micrurus tener to specific status. Roze (1996, Coral Snakes of the Americas, Kreiger Publishing) provided additional evidence that this taxon is a distinct species. Liner (1994, SSAR Herpetol. Circ. 23) and Collins (1997, SSAR Herpetol. Circ. 25) followed these recommendations. An ongoing study has failed to find any signs of recent intergradation around the geographical hiatus with M. fulvius (Jeff Boundy, pers. comm.).
M. t. tener (Baird and Girard, 1853)—Texas Coralsnake

Nerodia Baird and Girard, 1853—NORTH AMERICAN WATERSNAKES
N. clarkii (Baird and Girard, 1853)—Saltmarsh Snake
Lawson et al. (1991, Copeia 1991: 638–659) presented allozyme data that supported the separation of clarkii and fasciata.
N. c. clarkii (Baird and Girard, 1853)—Gulf Saltmarsh Snake
N. c. compressicauda Kennicott, 1860—Mangrove Saltmarsh Snake


N. c. taeniata (Cope, 1895)—Atlantic Saltmarsh Snake
Dunson (1979, Florida Scientist 42: 102–112) synonymized Nerodia c. taeniata with N. c. compressicauda, concluding that it was a pattern variant of the latter. Lawson et al. (1991, Copeia 1991: 638–659) resurrected N. c. taeniata on the basis of allozyme data, although the genetic distances were minute.
N. cyclopion (Duméril, Bibron, and Duméril, 1854)—Mississippi Green
Watersnake
N. erythrogaster (Forster, 1771)—Plain–bellied Watersnake
Reveiwed by McCranie (1990, Cat. Am. Amph. Rept. 500).
N. e. erythrogaster (Forster, 1771)—Red-bellied Watersnake
N. e. flavigaster (Conant, 1949)—Yellow-bellied Watersnake
N. e. neglecta (Conant, 1949)—Copper-bellied Watersnake
N. e. transversa (Hallowell, 1852)—Blotched Watersnake
N. fasciata (Linnaeus, 1766)—Southern Watersnake
Allozyme data indicate that Nerodia fasciata forms two clades, differentiated on the mid–Florida Panhandle (Lawson et al., 1991, Copeia 1991: 638–659). Also see note under N. sipedon.
N. f. confluens (Blanchard, 1923)—Broad-banded Watersnake
N. f. fasciata (Linnaeus, 1766)—Banded Watersnake
N. f. pictiventris (Cope, 1895)—Florida Watersnake
N. floridana (Goff, 1936)—Florida Green Watersnake
Elevation of floridana from the status as a race of N. cyclopion is supported by data from Pearson (1966, Bull. Serol. Mus. 36: 8), Lawson (1987, J. Herpetol. 21: 140–157), and Sanderson (1993, Brimleyana 19: 83–94). The disjunct populations of floridana were examined by Thompson and Crother (1998, Copeia 1998: 715–719) with allozyme data which revealed no evidence for divergence.
N. harteri (Trapido, 1941)—Brazos River Watersnake
Reviewed by Mecham (1983, Cat. Am. Amph. Rept. 330; includes N. paucimaculata).
N. paucimaculata (Tinkle and Conant, 1961)—Concho Watersnake
Suggested to be separated from harteri by Rose and Selcer (1989, J. Herpetol. 23: 261–266) and supported by molecular data in Densmore et al. (1992, Herpetologica 48: 60–68).
N. rhombifer (Hallowell, 1852)—Diamond-backed Watersnake
Reviewed by McAllister (1985, Cat. Am. Amph. Rept. 376).
N. r. rhombifer (Hallowell, 1852)—Northern Diamond-backed
Watersnake
N. sipedon (Linnaeus, 1758)—Northern Watersnake
Numerous examples exist of hybridization between sipedon and fasciata (Conant, 1963, Am. Mus. Novit. 2122: 1–38; Blaney and Blaney, 1979, Herpetologica 35: 350–359; Schwaner et al. 1980, Isozyme Bull. 12: 102; Schwaner and Mount, 1976, Occas. Pap. Mus. Nat. Hist. Univ. Kansas 45: 1–44), although sipedon and fasciata are apparently not sister taxa (Lawson,1987, J. Herpetol. 21: 140–157).
N. s. insularum (Conant and Clay, 1937)—Lake Erie Watersnake
N. s. pleuralis (Cope, 1892)—Midland Watersnake
N. s. sipedon (Linnaeus, 1758)—Northern Watersnake
N. s. williamengelsi (Conant and Lazell, 1973)—Carolina Watersnake
N. taxispilota (Holbrook, 1838)—Brown Watersnake
Reviewed by McCranie (1983, Cat. Am. Amph. Rept. 331).

Opheodrys Fitzinger, 1843—GREENSNAKES
O. aestivus (Linnaeus, 1766)—Rough Greensnake
Recognition of the Florida peninsular form described by Grobman (1984, Bull. Florida St. Mus. Biol. Sci. 29: 153–170) is supported by Plummer (1987, Copeia 1987: 483–485).
O. a. aestivus (Linnaeus, 1766)—Northern Rough Greensnake
O. a. carinatus Grobman, 1984—Florida Rough Greensnake
O. vernalis (Harlan, 1827)—Smooth Greensnake
Cundall (1981, Copeia, 1981: 353–371) removed all the Asiatic species from Opheodrys and retained only aestivus and vernalis in the genus. Given that Liochlorophis (Oldham and Smith, 1991, Bull. Maryland Herpetol. Soc. 27: 201–215) is the monotypic sister genus to the monotypic genus Opheodrys, recognition of the former taxon is unnecessary, and reduces the amount of information conveyed by the names. As such, we retain vernalis in Opheodrys. The several subspecies described by Grobman (1941, Misc. Pub. Mus. Zool. Univ. Michigan 50: 1–38; 1992, J. Herpetol. 26: 176–186) are based on character clines and have received little recognition.

Oxybelis Wagler, 1830—AMERICAN VINESNAKES
O. aeneus (Wagler, 1824)—Brown Vinesnake
Reviewed by Keiser (1982, Cat. Am. Amph. Rept. 305).

Pelamis Daudin, 1803—YELLOW-BELLIED SEASNAKES
P. platurus (Linnaeus, 1766)—Yellow-bellied Seasnake
Reviewed by Pickwell and Culotta (1980, Cat. Am. Amph. Rept. 255).

Phyllorhynchus Stejneger, 1890 LEAF-NOSED SNAKES
P. browni Stejneger, 1890—Saddled Leaf-nosed Snake
P. decurtatus (Cope, 1868)—Spotted Leaf-nosed Snake
We follow McDiarmid and McCleary (1993, Cat. Am. Amph. Rept. 579), who argued that the four subspecies of browni and five subspecies of decurtatus not be recognized, pending a more detailed review of the genus in progress (J. Mendelson, pers. comm.).

Pituophis Holbrook, 1842—BULLSNAKES, GOPHERSNAKES, and PINESNAKES
Reichling (1995, J. Herpetol. 29: 186–198) clustered Pituophis catenifer subspecies and P. melanoleucas subspecies separately, and also was able to distinguish among the subspecies, in phenetic space. J. Matos (pers. comm.), using sequence data, supported Reichling’s arrangement, but found P. ruthveni and P. c. sayi to be sister taxa. Matos also found distinctive clades within western subspecies so taxonomic changes within this widespread taxon should be anticipated.
P. catenifer (Blainville, 1835)—Gophersnake
P. c. affinis (Hallowell, 1852)—Sonoran Gophersnake
P. c. annectens Baird and Girard, 1853—San Diego Gophersnake
P. c. catenifer (Blainville, 1835)—Pacific Gophersnake
P. c. deserticola Stejneger, 1893—Great Basin Gophersnake
P. c. pumilus Klauber, 1946—Santa Cruz Island Gophersnake
P. c. sayi (Schlegel, 1837)—Bullsnake
P. melanoleucus (Daudin, 1803)—Pinesnake
Reviewed by Sweet and Parker (1990, Cat. Am. Amph. Rept. 474; includes P. catenifer, P. ruthveni).
P. m. lodingi Blanchard, 1924—Black Pinesnake
P. m. melanoleucus (Daudin, 1803)—Northern Pinesnake
P. m. mugitus Barbour, 1921—Florida Pinesnake
P. ruthveni Stull, 1929—Louisiana Pinesnake
Reichling (1995, J. Herpetology 29: 186–198) concluded that ruthveni is a distinct species, supporting Collins’ (1991, Herpetol. Rev. 22: 42–43) previous suggestion.

Ramphotyphlops Fitzinger, 1843—AUSTRALASIAN BLINDSNAKES
(Introduced)
R. braminus (Daudin, 1803)—Brahminy Blindsnake (Introduced) (Unisexual)

Regina Baird and Girard, 1853—CRAYFISH SNAKES
Lawson (1987, J. Herpetol. 21:140–157) presented data that indicated this genus is not a natural group, i.e. not monophyletic, and requires further research to tease out the nature of the lineages involved.
R. alleni (Garman, 1874)—Striped Crayfish Snake
R. grahamii Baird and Girard, 1853—Graham’s Crayfish Snake
R. rigida (Say, 1825)—Glossy Crayfish Snake
R. r. deltae (Huheey, 1959)—Delta Crayfish Snake
R. r. rigida (Say, 1825)—Glossy Crayfish Snake
R. r. sinicola (Huheey, 1959)—Gulf Crayfish Snake
R. septemvittata (Say, 1825)—Queen Snake

Rhadinaea Cope, 1863—LITTERSNAKES
R. flavilata (Cope, 1871)—Pine Woods Littersnake
Reviewed by Walley (1998, Cat. Am. Amph. Rept. 699).

Rhinocheilus Baird and Girard, 1853—LONG-NOSED SNAKES
R. lecontei Baird and Girard, 1853—Long-nosed Snake
Reviewed by Medica (1975, Cat. Am. Amph. Rept. 175).
R. l. lecontei Baird and Girard, 1853—Western Long-nosed Snake
R. l. tessellatus Garman, 1883—Texas Long-nosed Snake

Salvadora Baird and Girard, 1853—PATCH-NOSED SNAKES
S. grahamiae Baird and Girard, 1853—Eastern Patch-nosed Snake
S. g. grahamiae Baird and Girard, 1853—Mountain Patch-nosed Snake
S. g. lineata Schmidt, 1940—Texas Patch-nosed Snake
S. hexalepis (Cope, 1866)—Western Patch-nosed Snake
S. h. deserticola Schmidt, 1940—Big Bend Patch-nosed Snake
Recognition of deserticola as a species was done without explanation by Bogert and Degenhardt (1961, Am. Mus. Novit. 2064: 13). Bogert (1985, Snake Syst. Newsl. Nov. no. 3) explained that the usage was based on characters discovered previously (Bogert, 1945, Am. Mus. Novit. 1285: 1–14) and on the absence of any intergrades. Although Bogert may be correct, we await a study to demonstrate it and retain deserticola as a subspeceis of hexalepis.
S. h. hexalepis (Cope, 1866)—Desert Patch-nosed Snake
S. h. mojavensis Bogert, 1945—Mojave Patch-nosed Snake
S. h. virgultea Bogert, 1935—Coast Patch-nosed Snake

Seminatrix Cope, 1895—BLACK SWAMPSNAKES
Reviewed by Dorcas et al. (covers Seminatrix and S. pygaea) (1998, Cat. Am. Amph. Rept. 679).
S. pygaea (Cope, 1871)—Black Swampsnake
S. p. cyclas Dowling, 1950—Southern Florida Swampsnake
S. p. paludis Dowling, 1950—Carolina Swampsnake
S. p. pygaea (Cope, 1871)—Northern Florida Swampsnake

Senticolis Dowling and Fries, 1987—GREEN RATSNAKES
Reviewed by Price (1991, Cat. Am. Amph. Rept. 525). Schulz (1996, A Monograph of the Colubrid Snakes of the Genus Elaphe Fitzinger, Koeltz Scientific Books) applied the generic name of Elaphe to this species due to his opinion that the genus Elaphe is in need of an overall revision, but not because Schulz disagreed with Dowling and Fries (1987, Herpetologica 43: 200–207). We concur that Elaphe is in need of systematic revision globally, but retain Senticolis. Keogh (1996, Herpetologica 52: 406–416) demonstrated the separation of Elaphe and Senticolis in a phylogenetic context.
S. triaspis (Cope, 1866)—Green Ratsnake
S. t. intermedia (Boettger, 1883)—Northern Green Ratsnake

Sistrurus Garman, 1883—PYGMY RATTLESNAKES
See annotation under Crotalus.
S. catenatus (Rafinesque, 1818)—Massasauga
The status of the subspecies appears to be arbitrary delimitation of continuous morphological and ecological variation. Reviewed by Minton (1983, Cat. Am. Amph. Rept. 332).
S. c. catenatus (Rafinesque, 1818)—Eastern Massasauga
S. c. edwardsii (Baird and Girard, 1853)—Desert Massasauga
S. c. tergeminus (Say, 1823)—Western Massasauga
S. miliarius (Linnaeus, 1766)—Pygmy Rattlesnake
Reviewed by Palmer (1978, Cat. Am. Amph. Rept. 220).
S. m. barbouri Gloyd, 1935—Dusky Pygmy Rattlesnake
Gloyd (1935, Occ. Papers Mus. Zool. Univ. Michigan 322: 1–7) found S. m. barbouri distinct from the other two races by having the lateral spots in 3 series vs. 1–2 series for the other two.
S. m. miliarius (Linnaeus, 1766)—Carolina Pygmy Rattlesnake
S. m. streckeri Gloyd, 1935—Western Pygmy Rattlesnake

Sonora Baird and Girard, 1853—NORTH AMERICAN GROUNDSNAKES
Reviewed by Frost (1983, Cat. Am. Amph. Rept. 333).
S. semiannulata Baird and Girard, 1853—Groundsnake



Stilosoma Brown, 1890—SHORT-TAILED SNAKES
Dowling and Maxson (1990, J. Zool. London 221: 77–85), using immunological distance data, found Stilosoma to fall within Lampropeltis. Keogh (1996, Herpetologica 52: 406–416), however, did not recover a paraphyletic Lampropeltis with respect to Stilosoma, but found Stilosoma as part of the probable sister group to Lampropeltis.
S. extenuatum Brown, 1890—Short-tailed Snake
Reviewed by Highton (1976, Cat. Am. Amph. Rept. 183).

Storeria Baird and Girard, 1853—NORTH AMERICAN BROWNSNAKES
S. dekayi (Holbrook, 1836)—DeKay’s Brownsnake
Reviewed by Christman (1982, Cat. Am. Amph. Rept. 306).
S. d. dekayi (Holbrook, 1836)—Northern Brownsnake
S. d. limnetes Anderson, 1961—Marsh Brownsnake
S. d. texana Trapido, 1944—Texas Brownsnake
S. d. wrightorum Trapido, 1944—Midland Brownsnake
S. occipitomaculata (Storer, 1839)—Red-bellied Snake
S. o. obscura Trapido, 1944—Florida Red-bellied Snake
S. o. occipitomaculata (Storer, 1839)—Northern Red-bellied Snake
No evidence of separate lineages has been found between the sympatric brown and grey color morphs (Grudzien and Owens, 1991, J. Herpetol. 25: 90–92).
S. o. pahasapae Smith, 1963—Black Hills Red-bellied Snake
S. victa Hay, 1892—Florida Brownsnake
Christman (1980, Bull. Florida St. Mus. 25: 157–256) presented evidence to suggest species status for victa.

Tantilla Baird and Girard, 1853—BLACK-HEADED SNAKES
T. atriceps (Günther, 1895)—Mexican Black-headed Snake
Reviewed by Cole and Hardy (1983, Cat. Am. Amph. Rept. 317).
T. coronata Baird and Girard, 1853—Southeastern Crowned Snake
Reviewed by Telford (1982, Cat. Am. Amph. Rept. 308).
T. cucullata Minton, 1956—Trans-Pecos Black-headed Snake
The taxonomic status of cucullata and diabola has been problematic. They have been alternately synonymized (Degenhardt et al., 1976, Texas J. Sci. 17: 225–234; Hillis and Campbell, 1982, Southwest. Nat. 27: 220–221; Irwin and Collins, 1995, Herpetol. Rev. 26: 47) or elevated to species (Collins, 1991, Herpetol. Rev. 22: 42–43). Most recently Wilson (1999, Smithsonian Inform. Service 122: 1–34) and Dixon et al. (2000, Southwest Nat. 45: 141–153) elevated cucullata and synonymized diabola.
T. gracilis Baird and Girard, 1853—Flat-headed Snake
T. hobartsmithi Taylor, 1937—Smith’s Black-headed Snake
Reviewed by Cole and Hardy (1983, Cat. Am. Amph. Rept. 318).
T. nigriceps Kennicott, 1860—Plains Black-headed Snake
T. oolitica Telford, 1966—Rim Rock Crowned Snake
Reviewed by Telford (1980, Cat. Am. Amph. Rept. 256).
T. planiceps (Blainville, 1835)—Western Black-headed Snake
Cole and Hardy (1981, Bull. Am. Mus. Nat. Hist. 17: 201–284) noted local geographic variation but did not recognize any available subspecies of the many disjunct populations. Reviewed by Cole and Hardy (1983, Cat. Am. Amph. Rept. 319).
T. relicta Telford, 1966—Florida Crowned Snake
Reviewed by Telford (1980, Cat. Am. Amph. Rept. 257).
T. r. neilli Telford, 1966—Central Florida Crowned Snake
T. r. pamlica Telford, 1966—Coastal Dunes Crowned Snake
T. r. relicta Telford, 1966—Peninsula Crowned Snake
T. wilcoxi Stejneger, 1902—Chihuahuan Black-headed Snake
Reviewed by Liner (1983, Cat. Am. Amph. Rept. 345).
T. yaquia Smith, 1942—Yaqui Black-headed Snake
Reviewed by McDiarmid (1977, Cat. Am. Amph. Rept. 198).

Thamnophis Fitzinger, 1843—NORTH AMERICAN GARTERSNAKES
The specific and infraspecific status of the taxa listed below is from Rossman et al. (1996, The Garter Snakes, Univ. Oklahoma Press).
T. atratus (Kennicott, 1860)—Aquatic Gartersnake
Rossman and Stewart (1987, Occ. Pap. Mus. Zool. Louisiana St. Univ. 63: 1–25) recognized atratus as distinct from Thamnophis couchii and recommended against recognizing T. a. aquaticus.
T. a. atratus (Kennicott, 1860)—Santa Cruz Gartersnake
T. a. hydrophilus Fitch, 1936—Oregon Gartersnake
T. a. zaxanthus Boundy, 1999—Diablo Range Gartersnake
T. brachystoma (Cope, 1892)—Short-headed Gartersnake
Reviewed by Bothner (1976, Cat. Am. Amph. Rept. 190).
T. butleri (Cope, 1889)—Butler’s Gartersnake
Reviewed by Minton (1980, Cat. Am. Amph. Rept. 258).
T. couchii (Kennicott, 1859)—Sierra Gartersnake
Reviewed by Fitch (1984, Cat. Am. Amph. Rept. 351; includes T. gigas, T. atratus, T. hammondii).
T. cyrtopsis (Kennicott, 1860)—Black-necked Gartersnake
Reviewed by Webb (1980, Cat. Am. Amph. Rept. 245).
T. c. cyrtopsis (Kennicott, 1860)—Western Black-necked Gartersnake
T. c. ocellatus (Cope, 1880)—Eastern Black-necked Gartersnake
T. elegans (Baird and Girard, 1853)—Terrestrial Gartersnake
Reviewed by Fitch (1983, Cat. Am. Amph. Rept. 320). Although six subspecies (one is extralimital) are currently recognized, Rossman et al. (1996, The Garter Snakes, Univ. Oklahoma Press) stress the need for a detailed study of geographic variation in this taxon.
T. e. arizonae Tanner and Lowe, 1989—Arizona Wandering
Gartersnake
T. e. elegans (Baird and Girard, 1853)—Mountain Gartersnake
T. e. terrestris Fox, 1951—Coast Gartersnake
T. e. vagrans Baird and Girard, 1853—Intermountain Wandering
Gartersnake
T. e. vascotanneri Tanner and Lowe 1989—Upper Basin Gartersnake
T. eques (Reuss, 1834)— Mexican Gartersnake
T. e. megalops (Kennicott, 1860)—Northern Mexican Gartersnake
T. gigas Fitch, 1940—Giant Gartersnake
T. hammondii (Kennicott, 1860 )—Two-striped Gartersnake
The extralimital T. digueti was synonymized with T. hammondi by McGuire and Grismer (1993, Herpetologica 49: 354–365).
T. marcianus (Baird and Girard, 1853)—Checkered Gartersnake
T. m. marcianus (Baird and Girard, 1853)—Marcy’s Checkered Gartersnake
T. ordinoides (Baird and Girard, 1852)—Northwestern Gartersnake
Reviewed by Kirk (1979, Cat. Am. Amph. Rept. 233).
T. proximus (Say, 1823)—Western Ribbonsnake
Reviewed by Rossman (1970, Cat. Am. Amph. Rept. 98).
T. p. diabolicus Rossman, 1963—Arid Land Ribbonsnake
T. p. orarius Rossman, 1963—Gulf Coast Ribbonsnake
T. p. proximus (Say, 1823)—Orange-striped Ribbonsnake
T. p. rubrilineatus Rossman, 1963—Red-striped Ribbonsnake

T. radix (Baird and Girard, 1853)—Plains Gartersnake
T. rufipunctatus (Cope, 1875)—Narrow-headed Gartersnake
Based on scale microstructure, Chiasson and Lowe (1989, J. Herpetol. 23: 109–118) suggested that this taxon be moved from Thamnophis to Nerodia. De Queiroz and Lawson (1994, Biol. J. Linnean Soc. 53: 209–229) rejected the suggested reallocation, based on their finding that rufipunctatus is nested within Thamnophis. Reviewed by Tanner (1990, Cat. Am. Amph. Rept. 505).
T. sauritus (Linnaeus, 1766)—Eastern Ribbonsnake
Reviewed by Rossman (1970, Cat. Am. Amph. Rept. 99).
T. s. nitae Rossman, 1963—Blue-striped Ribbonsnake
T. s. sackenii (Kennicott, 1859)—Peninsula Ribbonsnake
T. s. sauritus (Linnaeus, 1766)—Common Ribbonsnake
T. s. septentrionalis Rossman, 1963—Northern Ribbonsnake
T. sirtalis (Linnaeus, 1758)—Common Gartersnake
Reviewed by Fitch (1980, Cat. Am. Amph. Rept. 270).
T. s. annectens Brown, 1950—Texas Gartersnake
T. s. concinnus (Hallowell, 1852)—Red-spotted Gartersnake
T. s. dorsalis (Baird and Girard, 1853)—New Mexico Gartersnake
T. s. fitchi Fox, 1951—Valley Gartersnake
T. s. infernalis (Blainville, 1835)—San Francisco Gartersnake
Boundy and Rossman (1995, Copeia 1995: 236–240) found that the holotype of infernalis is a specimen of tetrataenia, and proposed replacement of the latter name with the older name infernalis, for San Francisco Gartersnake. They referred to concinnus the populations formerly referred to as infernalis on the basis of color pattern similarities. Barry et al. (1996, Herpetol. Rev. 27: 172–173) have petitioned the ICZN to suppress the changes proposed by Boundy and Rossman. We follow Boundy and Rossman until the ICZN decides.
T. s. pallidulus Allen, 1899—Maritime Gartersnake
T. s. parietalis (Say, 1823)—Red-sided Gartersnake
T. s. pickeringii (Baird and Girard, 1853)—Puget Sound Gartersnake
T. s. semifasciatus Cope, 1892—Chicago Gartersnake
Benton (1980, Zool. J. Linnaean Soc. 68: 307–323) synonymized semifasciatus with the nominate race, but Rossman et al. (1996, The Gartersnakes. Evolution and Ecology, Univ. Oklahoma Press) resurrected semifasciatus.
T. s. similis Rossman, 1965—Blue-striped Gartersnake
T. s. sirtalis (Linnaeus, 1758)—Eastern Gartersnake
Trimorphodon Cope, 1861—LYRESNAKES
T. biscutatus (Duméril, Bibron and Duméril, 1854)—Western Lyresnake
Reviewed by Scott and McDiarmid (1984, Cat. Am. Amph. Rept. 353).
T. b. lambda Cope, 1886—Sonoran Lyresnake
T. b. lyrophanes (Cope, 1860)—California Lyresnake
Grismer et al. (1994, Bull. So. California Acad. Sci. 93: 45–80) synonymized T. b. vandenburghi Klauber 1924 with T. b. lyrophanes.
T. b. vilkinsonii Cope, 1886—Texas Lyresnake

Tropidoclonion Cope, 1860—LINED SNAKES
T. lineatum (Hallowell, 1856)—Lined Snake
See comments under Virginia.

Virginia Baird and Girard, 1853—NORTH AMERICAN EARTHSNAKES
V. striatula (Linnaeus, 1766)—Rough Earthsnake
Reviewed by Powell et al. (1994, Cat. Am. Amph. Rept. 599).
V. valeriae Baird and Girard, 1853—Smooth Earthsnake
Reviewed by Powell et al. (1992, Cat. Am. Amph. Rept. 552).
V. v. elegans Kennicott, 1859—Western Smooth Earthsnake
V. v. valeriae Baird and Girard, 1853—Eastern Smooth Earthsnake
V. v. pulchra (Richmond, 1954)—Mountain Earthsnake
Lawson (1985, Ph.D. dissertation, Louisiana St. Univ.) argued for the possibility that Virginia is paraphyletic with respect to Tropidoclonion and suggested expanding the genus Virginia to include Tropidoclonion lineatum. Collins (1991, Herpetol. Rev. 22: 42–43) elevated pulchra to specific status. Because no supporting data, aside from allopatric distribution, was published in his list, we retain V. valeriae pulchra.