4-8. CROTALUS 9+9 



only known from a few localities in southern Arizona near 

 the Mexican boundary, until in 1891 the Death Valley ex- 

 ploration under Dr. Merriam extended its range very materi- 

 ally into the desert mountains of southern California and 

 Nevada south of the thirty-seventh parallel, from Owen's 

 Valley to the great bend of the Colorado." The vertical range 

 is at least 2,000 to 8,000 feet above sea-level. Some of the 

 localities at which this snake has been taken are: Rocky Creek, 

 Independence Creek, Lone Pine, Owens Valley, Coso Valley, 

 Argus Range, Panamint Mountains, Slate Range, Wild Rose 

 Springs, Beveridge Canyon in the Inyo Mountains, all in 

 Inyo County} Round Valley in Mono County; and 20 miles 

 above Picacho, Colorado River, Imperial County; Califor- 

 nia; Vegas Valley, Vegas Wash, Indian Spring Valley, and 

 Grapevine Mountains, Nevada; and Catalina Mountains, 

 Pima County; Fort Buchanan, Santa Cruz County; Sierra 

 del Poso Verde, and the Coyote Mountains 40 miles south- 

 west from Tucson, Arizona. 



Habits. This snake seems to be of partially nocturnal 

 habits. It feeds upon small mammals, such as kangaroo rats 

 and pocket mice. It probably mates in April. It inhabits 

 rocky situations as well as sandy places. In the latter it has 

 the habit of worming out shallow depressions in which it 

 reposes flush with the surface and is difficult to see, especially 

 since its coloring is such as to blend with its surroundings. 



2 1 7. Crotalus mitchellii Cope 

 BLEACHED RATTLESNAKE 

 Plates 104, 114, and 115 



Caudisona Mitchellii COPE, Proc. Acad. Nat. Sci. Phila., 1861, p. 293 

 (type locality, Cape St. Lucas, Lower California, Mexico); 

 ,Proc. Acad. Nat. Sci. Phila., 1866, p to. 



