Artificial Key to the Snakes 
143 
* 9 ° 7 \ 
Top of head reddish, colors paler. Copperhead ( Ancis - 
tron contortrix). 
11. Upper parts unmarked. 12. 
Upperparts with evident markings. 22. 
12. Upper parts green. 13. 
Upper parts not green. 14. 
13. fScales keeled. Southern Green Snake ( Cyclophis aesti- 
vus). 
Scales smooth. Northern Green Snake ( Liopeltis ver- 
nalis). 
14. Color of upper parts black. 15. 
Color of upper parts some shade of brown. 17. 
15. Snout recurved and keeled. Scales keeled. Black Adder 
( Heterodon platyrhmus var. niger). 
Snout as usual, not recurved nor keeled. 16. 
16. Scales all smooth. Underparts slaty black except the 
throat which is white. Black Snake ( Bascanion con- 
strictor). 
Middle rows of scales faintly keeled. Underparts black- 
ish, except for about the front third, which is white. 
Chicken Snake ( Coluber obsoletus). 
17. Scales keeled. 18. 
Scales smooth. 19. 
18. Size small, under 1 ft. when adult. Brown Snake ( Hal - 
dea striatula). 
Size large. Coppery red below. Copperbelly ( Natrix 
f erythrogastra ) . 
19. Size large. (Young crossbanded, a foot long when 
hatched.) Coachwhip ( Bascanion Jlagellum). 
Size small, under one foot when adult. 20. 
+ The scales of a snake are either perfectly smooth or else with a little 
ridge down the middle, in the latter case they are said to be keeled. 
