256 COLUBRID.E. 



a. Seven upper labials ; portion of rostral visible from above 

 not more than half as long as its distance from the 

 frontal. 



a. Ventrals 103-148. 



Scales in 1.5 rows ; subcaudal? 65-94 .... 2. vernalis, p. 258. 

 Scales in 13 rows ; subcaudals 51-64 .... 3. agassizii, p. 259. 

 Scales in 15 to 19 rows ; subcaudals 24-52. 11. coronella, p. 264. 



(S. Ventrals 150-235 ; subcaudals 48-85 ; scales in 15 or 

 17 rows. 



* Hostral as deep as broad or a little broader than 



deep; scales in 15 or 17 rows; ventrals 150-191. 

 Frojtal at least twice as long as broad . . 4. decemlhieaia, i>.2iJ0 

 Prontal not twice as long as broad 5. collaris, p. 260. 



** Rostral considerablj- broader than deep ; scales in 

 15 rows. 



t Frontal as long as the 2>arietals ; ventrals 158-171 . 

 6. fasciata, p. 262. 



ft Frontal much shorter than the parietals. 



Frontal once and two thirds as long as 



broad ; ventrals 186 7. anc/usticeps, p. 262, 



Frontal not once and a half as long as 



broad : ventrals 169-187 8- rothi, p. 262. 



Frontal once and a half as long as broad, 



about once and a half as broad as the 



supraocular; ventrals 194-216 9 persica, p. 263. 



Frontal once and a half as long as broad, 



nearly twice as broad as the supraocular; 



ventrals 211-235 10. walteri, p. 263. 



6. Seven upper labials ; portion of rostral visible from above 

 measuring one half to two thirds its distance from the 

 frontal. 



a. Scales in 13 rows ; ventrals 126-137 ; subcaudals 

 37-46 12. tcuilori, p, 265. 



/3. Scales in 15 rows. 



* Body without black cross bars. 



Ventrals 145-163 13. episcopa, p. 265. 



Ventrals 183 14. torqmita, p. 266. 



** 



Body with black cross bars. 



Ventrals 158-167 ; subcaudals 50-52 .... 15. isozona, p. 266. 

 Ventrals 147-158; subcaudals 34-44 16. occipitalis, p. 266. 



