54 BULLETIN 18 7, UNITED STATES NATIONAL MUSEUM 



Species. — One, with eight subspecies, six occurring in Mexico ; extra- 

 limital are couperi of southeastern United States and corah of South 

 America. 



KEY TO MEXICAN FORm's OF DRYMARCHON 



1. Subcaudals less than 68 (55 to 65); ventrals 193 or less; scale rows 



usually 14 near anus corais erebennus 



Subcaudals more than 68 (69 to 83) ; scale rows usually 15 near anus 2 



2. Anterior portion of body light brown, extreme posterior portion and tail 



black ; three vertical black streaks on posterior edges of subocular 

 labials and one on posterior edge of seventh labial, never any on preocular 

 labials (either above or below) ; lateral gular scales never black-tipped; 

 young lighter anteriorly than posteriorly, like adults, but with very 

 broad, light, chevron-shaped bands covering two scale lengths. 



corais nielanurus 

 Entire body and tail light brown above, or all black ; light bands in young 

 specimens narrow, covering about one scale length (?) 3 



3. Entire body brown above, and no darker posterioi'ly than anteriorly ; 



ventral surface of tail and posterior portion of body dark, but not black ; 

 young (and some adults) with distinct, longitudinal, short black streaks 



on anterior part of body corais unicoTor 



Entire body nearly uniform black above; belly black on posterior portion, 

 subcaudal surface black 4 



4. Light areas on supralabial region white or cream, very shai^ply defined 



from the black borders ; anterior portion of belly mostly light, salmon 



pink 5 



Most of head, including sides, black ; most of belly black, the light portions 

 cream or white, not reddish corais orizabensis 



5. Ventrals over 202 ; caudals 77 or more corais cleofae 



Ventrals less than 202 ; caudals 78 or less corais rubidus 



DRYMARCHON CORAIS CLEOFAE Brock 



Drymarchon corais cleofae Beock, Copeia, 1942, No. 4, pp. 249-250. 



Ty/^e.— Stanford Mus. Nat. Hist. No. 9447. 

 Type locality. — Maria Cleofa Island, Tres jSIarias Islands. 

 Range. — The Tres Marias Islands (recorded from Maria Madre, 

 Maria Magdalena, and Maria Cleofa Islands). 



DRYMARCHON CORAIS EREBENNUS (Cope) 



Spilotes eredennus Cope, Proc. Acad. Nat. Sci. Philadelphia, vol. 12, 1860, p. 342. 

 DryinarcTion corais erebennus Smith, Jouru. Washington Acad. Sci., vol. 31, 1941, 



pp. 478-479, map fig. 2. 

 Drymarchon corais melanurus Schmidt and Davis (nee Dum^ril and Bibron), 



Field book of snakes, 1941. pp. 134-135 (part), fig. 33 (body pattern). 

 Drymarchon corais olsoletus Schmidt and Owens, Publ. Field Mus. Nat. Hist., 



zool. ser., vol. 29, 1944, p. 110.^ 



^'Contrary to the statement of Smith {lov. cit.), Oeorgia ohsoleta Baird and Girard 

 (Catalogue of North American reptiles, 1853, pp. 158-159) is not a new name; it is simply 

 an allocation of Say's name, Coluber obsoletus {=Elaphe ohsoleta), to Baird and Girard's 



