6 University of Michigan 



Lampropeltis triangulum nelsoni, new subspecies 

 Plate I, Figure i 



1887. Ophibolus muUislratus Cope (part), Bull. U.S. Nat. Mus., No. 32, p. 78 



(Guanajuato). 

 1887. Ophibolus doliatus coccineus Cope (part), Bull. U.S. Nat. Mus., No. 32, 



p. 78 (Guadalajara; Colima). 

 1894. Coronella microplwlis var. A. Boulenger, Cat. Snakes Brit. Mus., II, 204. 

 1899. Lampropeltis micropholis oUgozona Stejneger, A^. Amer. Fauna, No. 14, 



p. 70 (Maria Madre Island). 



Diagnosis: Similar to L. triangulum annulata (Kennicott) and 

 to L. polyzona Cope, but distinguished from the former chiefly by 

 the fact that the snout region is mottled with lighter and the red 

 areas are broader and completely encircle the body; and from the 

 latter in the mottled instead of cross-banded snout, in the greater 

 width of the red rings, and the complete absence of black tips on 

 the red scales. 



Range: Western Mexico, from Acambaro in the state of 

 Guanajuato to southern Sinaloa and south to Colima, including 

 the Tres Marias Islands. 



Type Specimen: United States National Museum No. 46552; 

 collected by E. W. Nelson at Acambaro, Guanajuato, Mexico, in 

 October, 1892. 



Descripti&n of Type Specimen: Ventral plates, 206 ; anal single 

 and entire; caudals, 42 pairs; dorsal scale rows somewhat irregular 

 in number, for the most part 2 1 , but numbering only 20 anteriorly, 

 reaching 22 and 23 behind the middle, and ending with 19; upper 

 labials, 8 on each side, due to interpolation of a third; lower labials, 

 10 on the left side and 9 on the right; i preocular; 2 postoculars; 

 2 temporals in the first row and 3 in the second; loreal longer than 

 high; nasal divided; anterior chin shields in contact with each 

 other and with the first 4 lower labials; posterior chin shields 

 shorter and narrower than the anterior, in contact with each other 



