58 BULLETIN 18 7, UNITED STATES NATIONAL MUSEUM 



Genus ELAPHE Fitzinger 



Elaphe Fitzingeb, m? Wagler, Descriptiones et icones amphibioi-um, pt. 3, 183;3, text 

 to and pi. 27.— Smith, Copeia, 1941, No. 3, pp. 132-136, figs. 1, 2 (key to Mexi- 

 can species). 



Genotype. — Elaphe parreysii Fitzinger { = qaatuorlineata) . 



Range. — Europe, Asia, the Malay Archipelago, and central eastern 

 United States southward to Costa Rica. 



iSpecies. — Eight species and subspecies occur in Mexico; nine others, 

 occurring in the United States, do not reach Mexico. The Americas 

 accordingly have a total of 17 races. An indefinite number, probably 

 equally as many, occur in the Eastern Hemisphere. 



KEY TO MEXICAN FORMS OF ELAPHE 



1. No labials entering eye; a series of subocular scales present suboculaiis 



One or more labials entering eye; no suboculars 2 



2. Tbree labials entering eye^^ 3 



One or two labials entering eye 4 



3. Spots extending laterally to second or third scale row, partially eliminat- 



ing lateral series of spots; belly heavily pigmented posteriorly, tail 



uniform dark below ; 23 scale rows posteriorly flavirufa matudai 



Spots extending laterally to sixth or seventh scale row ; lateral spots regu- 

 lar, large; belly and tail white; 21 scale I'ows (usually) posteriorly. 



flavirufa flavirufa 



4. Scale rows 29 or less at midbody 5 



Scale rows 31 or more 6 



5. Adults and subadults unspotted, with broad stripes (sometimes faint) ; 



young with over 50 spots on body ; head unmarked ; subcaudals usually 



more numerous, 85 to 95 in females, 92 to 103 in males bairdi 



Spots present throughout life, less than 50 on body ; head with distinct, 

 large, alternating light and dark V-shaped marks ; subcaudals usually 

 fewer laeta laeta 



6. Spotted 7 



Gray, not spotted S 



7. Subcaudals 73 to 109; blotches present and distinct throughout life, 51 



or less on body triaspis 



Subcaudals 93 to 126 ; blotches present only in young, 57 to 58 on body. 



chlorosoma. 



8. Supralabials 10 or (usually) 11, one entering orbit; subcaudals S3 



to 88 rosaliae "^ 



Supralabials 8 or 9, two entering orbit; subcaudals 93 to 126 chlorosoma 



ELAPHE BAIRDI (Yarrow) 



Coluber bairdi Yakrow, in Cope, U. S. Nat. Mus. Bull. 17, 18S0, p. 41. 

 Elaphe bairdi Stejneger and Bakbour, A check list of North American am- 

 phibians and reptiles, ed. 1, 1917, p. 82. — Smith, Copeia, 1938, No. 3, p. I'-O. — 



'' Some specimens of triaspis enter this category, but these may be distinguished from 

 flavirvfa, with which they are most easily confounded, by the distinctly smaller eye. 

 '* The young of this species are not linown, but they may be spotted. 



