36 
NORTH AMERICAN BATRACHIA AND REPTILIA. 
33. C. vernalis , DeKay. Summer Snake. Color above 
green ; below yellowish ; tail between one-third and one-fourth 
total length; dorsal rows 15, all smooth; G. 130-140. Eastern 
and Austroriparian regions. 
34. C. cestivus , (Linn.) Gunther. Grass Snake. Color 
above bright green ; below yellowish-white ; tail more than one- 
third of total length ; dorsal rows 17, the vertebral ones strongly 
keeled; G. 150-160. Austroriparian region, north to New 
Jersey and Southern Illinois. 
14. Genus Coluber, Linn. 
Nasals two; loral present; anteorbitals one; postorbitals 
two ; dorsal scales slightly carinate along back, smooth on sides 
(the carinations sometimes obsolete); anal divided. 
A. Without longitudinal brown bands. 
a. Scales in 29 rows. 
35. C. emoryi , (B. and G.) Cope. Vertical longer than 
head ; color above ashy-gray, with a dorsal series of transverse 
brown blotches, and two smalleHateral rows (sometimes traces 
of a third); dorsal blotches narrowly margined with black; 
beneath yellowish-white, with indistinct brownish blotches; ten 
or twelve outer rows of dorsal scales smooth, the rest slightly 
carinated; G. 210-220. Mississippi Valley to Kansas and 
Illinois. 
36. C. lindheimeri , B. and G. Vertical as broad as long; 
a series of black dorsal and lateral blotches; intermediate 
spaces lighter; scales edged with white; beneath greenish- 
white; bluish slate color on centers of scutellae, especially pos- 
teriorly; dorsal scales obsoletely carinated; outer ten rows 
smooth; G. 225-235. Texas, Arkansas, and Southern Illinois. 
b. Scales in 25 rows ; vertical broader than long. 
37. C. vulpinus , B. and G. Fox Snake. Color above 
light brown, with about 60 transverse, quadrate, chocolate 
dorsal blotches, margined with black; one or two .lateral rows 
of same color; dorsal blotches three or four scales long; beneath 
yellowish-white, with alternating quadrate black blotches; the 
four lateral rows of scales smooth; G. 200-210. Massachusetts 
to Kansas, and northward. 
c. Scales in 25-27 rows; vertical longer than broad. 
38. C. obsoletus , subsp. obsoletus , (Say.) Cope. Pilot 
Snake. Color above uniform black; a few scales narrowly 
edged with white ; beneath slaty-black, except on the chin and 
