SYNOPSES AND DESCRIPTIONS. 53 



6rbit. Scales in 33—35 rows. Ventrals 229—239. Subcaudals 57 to 

 65 pairs. Reaches a length of seven feet. 



With the band across the frontal and behind the eye. More or less 

 spotted. Southwestern part of Mexico. (From descr.) 



B 

 . 



var. BELLONA. 



Ground color lighter than in P. melanoleucus. Body more slender; 

 apparently not reaching the same dimensions. In large specimens the 

 bar below the eye and that across the head to the angle of the mouth 

 are conspicuous. Dorsal series of spots from 70 to 80. Some specimens 

 have the colors very much faded, others have the spots very black and 

 distinct, particularly on the tail. The young have four alternating series 

 of spots on each flank, the lower on the outer edge of the abdomen. Scales 

 in 31 to 35 series. Ventrals 220—231. Subcaudals 43—63. I have taken 

 this species at great distances from water on the open prairies. Rocky 

 Mountain region. 



Elaphis. 



Elaphis Aldrovandm, 1040 and 1765; Bonaparte, 1831 and 1S40; 



Dumeril & Bibron, 1852 and 1S54; Giirdlur, 1858. 

 Elaphe FUzinger, 1833 and 1843. 



Of moderate slendcrness, slightly compressed, belly flat; head distinct 

 from the neck, crown flat, muzzle rounded; tail moderate, tapering. Eye 

 medium, pupil' round. Teeth equal, smooth. A loreal. Nasal in two 

 parts, nostril between. Orbitals 2 — 2 to 3. Scales keeled, in 19 to 25 

 rows. Anal bifid or entire. Subcaudals in two rows. In particular cases 

 the carination of the scales becomes obsolete. 



(JScotophis.) 



Anal entire; 



Light greyish-brown (reddish in life), with dorsal blotches of brown 



or black, varying to uniform black obsoletus. 



Pale red, with darker black-bordered blotches on the back, varying to 

 black, with a few white markings under the chin and neck 



guttatus. 

 Anal bifid ; 



with four longitudinal brownish bands qwdrivittatus. 



