13. COLUBRID/E 645 



e*. Rostral turned up at tip; scales in 17 rows. \ 



Picimia. p. 777. 

 c*. Loreal plate present. 



dd. Pupil round. ,,** 



ee. Rostral not free at edges, 

 ff. Normally one anterior temporal; urosteges 



fewer than 75; scales in 15 or 17 rows, 

 g. No narrow light transverse nuchal collar; 

 fourth infralabial usually largest; preocular 

 normally single and temporals 1+2. 

 h. Snout more or less depressed; each gastro- 

 stege not marked with a transverse blackish 

 bar. 



Sonora. p. 8 5 8. 



h'. Snout high ; each gastrostege with a narrow 

 transverse blackish bar. 



Contia. p. 770. 



g'. A narrow light transverse nuchal collar; 

 fifth infralabial usually largest; preoculars 

 normally two, and temporals 1 + 1 . 



Diadophis. p. 64-7. 



ff. Anterior temporals normally more than one; 

 urosteges more than 75; scales in 15 or more 

 rows; no single narrow nuchal collar, 

 gg. Scales in fewer than 23 rows; gastrosteges 

 fewer than 240. 



Coluber. p. 65 8. 



gg'. Scales in more than 30 rows; gastrosteges 

 more than 240. 



Elaphe. p.697. 



ee'. Rostral large, with free lateral edges; colora- 

 tion in longitudinal bands. 



Salvadora. p. 688. 



dd 1 . Pupil vertically elliptical. 



