THE PRINCIPAL SPECIES OF POISONOUS SNAKES 127 
series of scales between the supraoculars, 3 or 4 series of scales 
between the eye and the labials; 13—16 supralabials ; scales in 
25—29 rows, dorsals strongly keeled; ventrals 169—181 ; 24-—32 
subcaudals. 
Colour pale greyish or brownish, with a dorsal series of large 
blackish rhomboidal spots; a yellowish cross-line between the 
eyes; snout blackish; end of tail usually black; belly yellowish, 
more or less spotted with brown or black. 
Total length may be as much as 8 feet (2,400 millimetres). 
Habitat: South-eastern United States, from North Carolina 
to Florida and the mouths of the Mississippi. 
(5) C. horridus.—Supraoculars considerably narrower than the 
space between them, which is covered by 3—8 longitudinal series 
of small scales; 12—16 supralabials ; body scales in 23—29 rows, 
dorsals very strongly keeled; 165—178 ventrals ; 19—29 sub- 
caudals. 
Colour greyish-brown, usually with a rusty vertebral stripe, 
and V- or M-shaped blackish cross-bands ; head uniform above, 
with a dark band from the eye to the angle of the mouth; usually 
a pair of roundish or triangular dark spots on the nape; belly 
yellowish, uniform or spotted with blackish; end of tail blackish. 
Total length, 1,340 millimetres ; tail 135. 
Habitat: United States, from Massachusetts and Iowa to 
Northern Florida and Texas. 
(6) C. tigris. 
dorsals strongly keeled ; 166—181 ventrals ; 26—46 subcaudals. 
Colour yellowish or pale brown, with a dorsal series of brown 
spots and cross-bands posteriorly ; sides with smaller dark spots ; 
belly yellowish, spotted with brown. 
Total length, 380 millimetres ; tail 50. 
Habitat : Southern California, Lower California, Nevada, 
Colorado, Arizona, and Northern Mexico. 
13—15 supralabials ; scales in 23 or 25 rows, 
(7) C. mitchelli—14—16 supralabials ; scales in 25 rows, 
striated, dorsals strongly keeled; 178—198 ventrals ; 24—26 
subcaudals. 
