16. CROTALID^ 



only as darker portions of the general 'pepper and salt' style 

 of coloration. A dark band sometimes runs down and back 

 from the eye. The tail is gray, with four to six black cross- 

 bars. The lower surfaces are white or yellow, usually more 

 or less clouded with brown. 



Length to anus -.710 770 810 840 870 930 



Length of tail to rattle 62 74 72 60 71 90 



Remarks. — This rattlesnake seems to be most nearly re- 

 lated to C. tigris. It may usually be distinguished from 

 that species by its black bands on the tail as well as by the 

 granules between the rostral and anterior nasal plates. 



Distribution. — This rattlesnake has been found in the 

 Mohave and Colorado deserts of southeastern California, 

 and in central Arizona, and ranges the whole length of the 

 peninsula of Lower California. 



In Arizona, it has been found in the Tinajas Altas Range, 

 about fifty miles southeast from Yuma, and on the Colorado 

 River 20 miles above Picacho, Yuma County j on the Mo- 

 have Desert and at the foot of the Needles, Colorado River, 

 Mohave County j at Cave Creek, Maricopa County, and 

 near Fort Whipple, Yavapai County. 



In California, it has been collected in Los Angeles 

 (Fairmont), San Bernardino (Cushenbury Spring, Forest 

 Home, San Bernardino Mountains, one mile east from Oro 

 Grande, Victorville, Horn Mine, Turtle Mountains, 14 miles 

 northeast from Biythe Junction), Riverside (Asbestos Spring, 

 Santa Rosa Mountains, San Jacinto Mountains five miles 

 southwest from Banning), San Diego (Mountain Springs, 

 Campo, Boulevard, and Coyote Valley 25 miles east from 

 Oak Grove) counties. 



Lower California records are Cape San Lucas, La Paz, 

 Sierra El Taste, Miraflores, Sierra San Lazaro, Las Huavi- 



