174 EEPTILBS. 



ff. Snout not recurved and keeled ; species of large size. 

 jr. Gastrosteges 130 to 155 ; general color 3 series of dark 

 blotches on a lighter ground, sometimes simply- 

 barred or uniformly dark or reddish ; aquatic. 



Troptdonotus, 2. 

 gg. Gastrosteges 200 to 335 ; general color brown or black, 

 sometimes with quadrate blotches ; abdomen usually 

 blotched; terrestrial. . . . Colubbk, 8. 

 ** Dorsal scales smooth. 

 X Anal plate entire; gastrosteges 175 to 300- color black, brown 

 or red, more or less variegated. 

 h. Kows of scales 31 to 35 ; loral plate present. 



Ophiboltjs, 13. 



Tih. Rows of scales 19 ; no loral plate. . . Osceola, 13. 



XX Anal plate bifid; scales in 13 to 17 rows. 



i. Gastrosteges 170 to 310; scales in 17 rows; snakes very 



large or very long — ours lustrous pitch black in color 



when adult Bascantdm. 6. 



a. Gastrosteges less than 170; snakes of medium to small size. 

 j. Scales in 13 rows ; gastrosteges 130 to 135 ; brown, salmon 

 color or yellowish beneath. . Carphophiops, 18. 

 jj. Scales in 15 to 17 rows. 



k. Color black, unstriped ; a distinct yellowish ring about 



neck ; gastrosteges 140 to 160. . Diadophis, 11. 



kk. Color clear bright green; no collar; gastrosteges 130 



to 140 LlOPBLTIS, 10. 



kkk. Color brownish, with black dots ; no collar ; gastro- 

 steges 115 to 125 Virginia, 17. 



^X Anal plate bifid ; scales in 19 rows ; gastrosteges, 170 to 185. 

 I. Bluish black with squarish red spots on the blanks ; abdomen 



red with black spots Fabancia, 14. 



U. Blue-black, with three red lines ; abdomen yellowish with 

 a series of dark spots Abastor, 15. 



/. HETERODON, Beauvais. Spebading Adders. 

 1. H. platyrhinus, Latreille. Blowing Vipek. Hog- 



