224 



VERTEBRATE ANIMALS OF THE UNITED STATES 



of adult black; scales in 2^ to 25 rows; upper labials 13 or 14: entire 

 country east of the Great Plains; northward to Maine; southward to 

 northern Florida; in rocky regions, feeding on rodents and birds; bite 

 very dangerous. 



C adamanteiis Beauvois. Diamond-back rattlesnake. Length 

 1,800 mm.; tail 220 mm.; diameter of body 100 mm.; greatest length 

 2,500 mm. ; color olive or brown, with a dorsal series of about 20 more or 

 less irregular diamond-shaped markings, each diamond enclosing the 

 ground color; tail ringed with black; belly yellow; scales in 27 to 29 

 rows; upper labials 15: Atlantic and Gulf coastal regions, from North 



Carolina to Louisiana, in swamps and wet woods; 



the largest American poisonous snake. 



C. atrox Baird & Girard. Length 1,300 mm.; 



tail 150 mm.; color gray with a dorsal series of 



brown, diamond-shaped spots, each bordered with 



Fig. 127. — Crolalus horridus (from Cope). 



white; scales in 27 rows; upper labials 15 or 16: Arkansas to south- 

 eastern California, in arid regions; a feral colony exists in Wood 

 County, Wisconsin: common. 



C molossus B. & G. Length 1,000 mm.; tail 80 mm.; color sulphur 

 yellow, with a dorsal series of brown rhombs open at the side; tail black; 

 scales in 29 rows: southern Texas to southern Arizona. 



C. ruber Cope. A large rattler very like C. atrox, but reddish, with 

 indistinct marking: extreme southwestern California. 



C. cerastes Hollowell. Sidewinder. Length 480 mm. ; tail 50 mm. ; 

 a pair of conspicuous horn-like projections between the eyes; color light 

 brown, with a middorsal series of about 40 brown square spots and a 

 lateral series of small spots on each side; scales in 21 rows; upper labials 

 12: deserts of southern Utah and Nevada, Arizona and eastern Cali- 

 fornia; the popular name applies to a curious sidewise method of 

 locomotion. 



C. confluentus Say. Prairie rattler. Length 960 mm. ; tail 100 mm. ; 

 body rather slender; color yellowish brown or green, with a middorsal 

 series of about 40 irregularly rounded white-bordered brown blotches; 

 a pale band passes from beneath the center of the eye to the angle of 



