COLUBRID^E. LXXV. 173 



characters taken from the cephalic plates as not available 

 for my purpose. 

 * Dorsal scales carinated. 

 f Anal plate entire. 



a. Rows of scales 19 to 21 ; ventral plates (gastrosteges) 140 to 



170 ; general color 3 light stripes on a darker ground ; 

 sides usually with spots ; mostly viviparous. 



Eu rasNiA, 5. 



aa. Rows of scales 29 to 37 ; gastrosteges 200 to 240 ; general 

 color whitish with a triple series of dark blotches. 



PITYOPHIS, 7. 

 ff j^ual plate bifid. 



b. Rows of scales 15 to 17. 



c. Tail about one-third of total length ; gastrosteges 150 to 

 160 ; urosteges 100 or more ; color clear golden green. 



CYCLOPHIS, 9. 



cc. Tail much less than one-third of total length ; gastro 

 steges 125 to 130 ; urosteges 60 or less ; color brown or 

 reddish. 



d. With one or two faint grayish dorsal stripes and 



usually a broken dusky band along sides; small 



species: rows of scales 15 to 17; loral plate absent; 



anteorbital present. . . . STORERIA, 4. 



dd. No dorsal stripe; rows of scales 17; loral plate 



present ; anteorbital wanting. . HALDEA, 16. 



bb. Rows of scales 19 to 21. 



e. Gastrosteges 130 to 170 ; general color usually 3 or more 

 dark bands on a lighter ground ; size large.- 



TROPIDONOTUS, 2. 



ee. Gastrosteges 130 to 140 ; general color brown with many 

 obscure black cross-blotches, distinct on neck ; belly 

 salmon red with a row of black spots on each side ; 



size small TPVOPIDOCLONIUM, 3. 



bbb. Rows of scales 23 to 29. 



/. Form short and stout ; snout prominent, acute, recurved 

 and keeled, forming a sharp ridge; head flattened 

 when angry ; gastrosteges 125 to 150. HETERODON, 1. 



