24 INTRODUCTIOxN 



Upper labials usually separated from the eye by a 

 series of suboculars; preocular in contact with 

 the frontal ; scales smooth ; ventrals very dis- 

 tinctly angulate laterally, 222-258 ; subcaudals 



77-107 Zamenis hippocvepis. 



Two upper labials entering the eye; preocular not 

 in contact with the frontal ; scales feebly but dis- 

 tinctly keeled; ventrals not angulate laterally, 

 195-234; subcaudals 56-90. Coluber quatuorlineatus. 

 Two upper labials entering the eye ; preocular not 

 in contact with the frontal ; scales smooth or 

 faintly keeled ; ventrals not or but very obtusely 



angulate laterally, 172-214; subcaudals 50-80 



Coluber dione. 

 ft. No subocular ; scales smooth, or faintly 

 keeled on the posterior part of the body. 

 * Ventrals more than 200 ; scales with 

 two apical pits. 

 Snout obtuse; rostral broader than deep; scales in 

 21 or 23 rows; ventrals distinctly angulate later- 

 ally, 212-248 ; subcaudals 60-91 



Coluber longissimus. 

 Snout obtuse ; rostral broader than deep ; scales in 

 25 or 27 rows ; ventrals not angulate laterally, 

 222-260; subcaudals 68-90 ... Coluber leopardinus. 

 Snout pointed, strongly projecting ; rostral deeper 

 than broad, wedged in between the internasals ; 

 scales in 25 to 29 rows ; ventrals not angulate later- 

 ally, 201-220 ; subcaudals 48-68. Coluber scalaris. 



