CHECKLIST OF THE SNAKES OF MEXICO 75 



KEY TO MEXICAN FORMS OF IMANTODES 



1. Vertebral scales greatly enlarged, three to four times as wide as adjacent 



dorsals; bands symmetrical, usually not broken on sides of body 



posteriorly cenchoa leucomelas 



Vertebral scales not at all enlarged or not over twice width of adjacent 

 scales; bands variable 2 



2. Ventrals 240 or more 3 



Ventrals 236 or fewer 4 



3. Posterior dark bands on body broken laterally, poorly defined; spaces 



between anterior cross bars less than one scale length , gracillimus 



Bands distinct and symmetrical over all of body, usually none broken on 

 sides of body, all involving ends of ventrals or subcaudals; spaces 

 between cross bands half length of bands, or greater tenuissimus 



4. Vertebrals about twice as wide as adjacent scales gemmistratus 



Vertebrals not or but slightly enlarged, not twice as wide as adjacent 



dorsals 5 



5. Bauds with nearly straight anterior and posterior edges, very little, if any, 



narrower laterally than dorsally ; bands not broken on sides of body, but 

 becoming much less distinct toward tail, sometimes indistinguishable; 



ventrals 223 to 233 latistratus 



Bands narrower on sides of body than on middorsum, at least the posterior 

 ones broken laterally, and all very distinct and not becoming notably 

 fainter toward tail 6 



6. Body bands 34 to 39, only those on extreme posterior part of body broken 



laterally ; ventrals 198 to 201 splendidus splendidus 



Body bands 43 or more, broken laterally on at least posterior half of body, 

 sometimes on posterior two-thirds ; ventrals 205 or more 7 



7. Body bands 47 to 67, average 57, broken laterally on all except anterior 



third of body ; ventrals 222 to 235, average 229 splendidus oliveri 



Body bands 43 to 52, average 46, broken laterally only on posterior half of 

 body ; ventrals 205 to 225, average 219 splendidus luciodorsus 



IMANTODES CENCHOA LEUCOMELAS Cope 



Bimantodes leucomelas Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 13, 1861, 



p. 296. 

 Imantodes cenchoa leucomelas Smith, Proc. U. S. Nat. Mus., vol. 92, 1942, pp. 384— 



385, pi. 37, fig. 1 ; vol. 93, 1943, p. 434. 



Type.— V.S.N M. No. 25035-6, two cotypes. 



Type locality. — Mirador, Veracruz. 



Range. — Central Veracruz and southern Chiapas south into Guate- 

 mala on both coasts (recorded in IMexico from numerous localities in 

 the states of Campeche, Chiapas, Oaxaca, Tabasco, and Veracruz). 



IMANTODES GEMMISTRATUS Cope 



Ewiantodes cenchoa Cope (ticc Linnaeus), Proc. Acad. Nat. Sci. I'hiladelphia, vol. 



12, 1860, p. 264. 

 Himantodcs gemmistratus Copb:, ihid., vol. 13, 1861, pp. 296-297. 



Type. — Lost. 



Type locality. — Near Izalco, El Salvador. 



