The Rattlesnakes 



Division I. A chain of large, dark, pale-bordered rhombs 

 "diamonds." 



a. Diamond markings closed on sides. 

 fSize large. 



Dark olive; rhombs with yellow borders. 



DIAMOND-BACK RATTLESNAKE, C. adamanteus. 

 Distribution. Southeastern U. S. 



Grayish; rhombs with whitish borders. 



WESTERN DIAMOND RATTLESNAKE, C. atroX. 



Distribution. Texas to southern California. 

 Reddish; rhombs with whitish borders. 



RED DIAMOND RATTLESNAKE, C. atrox variety ruber. 

 Distribution. Southern and Lower California. 

 ffSize moderate. 



Dull white or pinkish, with very obscure, rhomb-like 

 markings. WHITE RATTLESNAKE, C. mitchellii. 



Distribution. Southern California, Lower California 

 and Arizona. 



b. Diamond markings narrowly open at sides and con- 

 tinued downward as narrow bands. 



Yellow or greenish. Two paler blotches within each 

 rhomb. BLACK-TAILED RATTLESNAKE, C. molossus. 

 Distribution. Arizona, New Mexico and Mexico. 



Division II. A row of rounded, dark-bordered blotches, 

 well separated. 



a. No horn over the eye. 



A pale band, one scale wide, in front of eye. 



PRAIRIE RATTLESNAKE, C. COnfluentuS. 



Distribution. Central United States; Canada to 



Mexico. 

 A pale band, two scales wide, in front of eye. 



PACIFIC RATTLESNAKE, C. OregOnUS. 



Distribution. Extreme Western States. 

 fffSize small. 



Two rows of blotches on forward portion, fusing into 

 a single row in rear of body. 



PRICE'S RATTLESNAKE, C. pricei. 

 Distribution. Arizona and Mexico. 



b. A horn over each eye. 



Yellowish; square, dull blotches on back and black spots 

 on sides. HORNED RATTLESNAKE, C. cerastes. 



Distribution. Deserts of Arizona, Nevada and Cali- 

 fornia. 



Division III. Markings in the form of dark, transverse bands, 

 a. Bands angular. 

 *Size moderate. 



439 



