134 BULLETIN 187, UNITED STATES NATIONAL MUSEUM 



Type locality. — Chihuitan, Oaxaca. 



Range. — The central and Pacific slopes of the Isthmus of Tehiiante- 

 pec (recorded from Chihuitan, El Barrio, Tres Cruces, and Mixte- 

 quilla Mountains, Oaxaca). 



Genus SYMPHOLIS Cope 



Sympholis Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 13, 1861 (1862), p. 524. 

 Genotype. — Sympholis lippiens Cope. 

 Range. — Western Jalisco and eastern Nayarit. 

 Species. — One. 



SYMPHOLIS LIPPIENS Cope 



Sympholis lippiens Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 13, 1861 (1862), 

 p. 524. 



Cheilorhina Villarsii Jan, Arch. Zool. Anat. Fis., vol. 2, 1862, pp. 54, 57 (type local- 

 ity, western Mexico; type in Milan, Torino Mus.) ; Iconographie g^nerale des 

 ophidiens, livr. 48, 1876, pi. 1, fig. 5. 



Type.—IJ.S.'^.'M.. Nos. 31345-6. 

 Type locality. — Guadalajara, Jalisco. 



Range. — Western Jalisco and eastern Nayarit (known only from 

 the type locality and from Tepic, Nayarit). 



Genus TANTILLA Baird and Girard 



Tantilla Baird and Gieabd, Catalogue of North American repties, 1853, p. 131. — 

 Smith, Zoologica, vol. 27, No. 7, 1942, pp. 33-42 (Mexican species). 



Genotype. — Tantilla coronata Baird and Girard. 

 Range. — Southern half of the United States southward through 

 Mexico and Central America into South America. 



Species. — About 45 species and subspecies, 27 in Mexico. 



KEY TO MEXICAN FORMS OF TANTILLA 



1. Ventral surface heavily pigmented moesta 



Ventral surface light, only extreme lateral tips of ventrals sometimes 



pigmented 2 



2. A lateral light stripe (a median also, but sometimes dim) at least ante- 



riorly ; no median middorsal dark stripe 3 



No lateral light stripes; ox', if present, a middorsal dark stripe also 

 present 4 



3. Two light spots on nuchal region, involving tips of parietals; ventrals 



157 to 165, caudals 34 to 42 striata 



A light nuchal collar, involving tips of parietals; ventrals 139 to 154, 

 caudals 40 to 50 jani 



4. A lateral light stripe and a middorsal dark stripe; neck as well as 



head dark, collar (if present) crossing neck several scales back of 



head mexicana 



Not as described 5 



5. Body with three or five distinct dark stripes 5a 



Body not striped ; or, if striped, with only a median stripe 8 



