CHECKLIST OF THE SNAKES OF MEXICO 115 



the states of Chiapas, Oaxaca, San Luis Potosi [Duges], Tabasco, and 

 Veracruz). 



Genus RHADINAEA Cope 



RJiadinaca Cope, Proc. Acad. Nat. Sci. Philadelphia, 1863, p. 100. — Baixey, Occ. 

 Pap. Mus. Zool. Univ. Michigan, No. 412, 1940, pp. 1-19, pis. 1-2 (revision 

 of Mexican species). 



Genotype. — Taeniophis vermiculaticeps Cope. 



Range. — Southeastern United States and southern Nuevo Leon 

 southward to South America. 



Species. — Fifteen species and subspecies are recorded in Mexico, an 

 indefinite number in Central and South America. 



KEY TO MEXICAN FORMS OF RHADINAEA" 



1. Three black longitudinal stripes separated sharply by narrow yellow 



lines on common border of rows 6 and 7; two lowermost rows and 



belly whitish aemula 



Color not as described above 2 



2. Seven upper labials ; middorsal stripe gray, about five scales wide, 



not sharply defined on edges ; a poorly defined lateral stripe usually 

 present on row 4 (or 3 and 4) ; color of head extending two or three 

 scale lengths behind parietals, usually bordered by a fine white 



collar laureata 



Eight upper labials; color not as described above, sides dark or with 

 a distinct lateral dark stripe 3 



3. No light temporal stripe extending back from upper corner of eye; 



a light bar from eye to corner of mouth lachrymans 



A liglit temporal stripe, often continuous with dorsolateral light stripes; 

 no light bar from eye to corner of mouth 4 



4. An isolated light spot on nape, separated by several scale lengths from 



dorsolateral and temporal light lines; ventrals less than 135 decorata 



Color not as described, temporal stripes fused with or separate from 

 dorsolateral light stripes (except sometimes in montana) ; ventrals 

 more than 135 5 



5. Temporal stripe continuous with dorsolateral light stripe, or if not, ex- 



tending to a line connecting posterior corners of mouth 6 



Temporal stripe not continuous with dorsolateral, extending posteriorly 

 no farther than secondary temporal 12 



6. Lateral stripe broad, black-edged, involving fourth and adjacent half 



rows, and, edges of median and lateral dark stripes much darker vittata 



Lateral stripe narrower, or, edges of median and lateral stripes not 



darker than middle of stripes 7 



7. Ends of ventrals not black-spotted 15 



Ends of ventrals black-spotted 8 



8. Inner boi-der of dorsolateral light lines on seventh scale row 9 



Inner border of dorsolateral light line on sixth scale row 10 



9. Lateral stripe on adjacent portions of third and fourth (mostly fourth) 



scale rows ; dorsolateral dark stripe involving adjacent portions of 

 seventh and eighth rows ; dorsal stripe distinct, but spotted, dis- 

 continuous quinquelineata 



*'' Adapted from Bailey, op. cit. 



