400 



LOWER VERTEBRATES. 



general color is reddish brown above, deeper along the back, and j-ellow beneath, 

 though a specimen that had just shed its skin, captured on the Columbia River, had 

 the ground color pure white, with sea-green patches on tlie back. Ordinarily, the 

 patches are in a series of sub-circular white rings, lined internally with a narrow black 

 line. The internasals are subdivided, and separated from the nasals by a row of 

 small scales. The rostral plate is small and pointed above, and pentagonal in form, 

 and there are from thirteen to sixteen labials. The scales of the body are arranged 

 in about twenty-five rows. Rattle-snakes are most abundant south of the Columbia 

 River ; west of the Cascade Range they are very rare. At the Dalles the present 

 species has been so abundant as to be very annoying, specimens someti?nes entering 



^^^^MflMHRGT. 



'^s^^ruCfj 



Fig. 231. — Crotaltis adamaiiteus, diamond-rattler, and C. durissus, rattle-snake. 



human dwellings, though of late, since the introduction of hogs, their numbers have 

 considerably decreased. The Indians, it is said, use the tail of this rattle-snake to 

 produce abortion. 



Crotalus adanianteus is distinguished by having the parietals and frontals scale- 

 like, the nasal divided, the loreals generally two, and the scales, the keels of which 

 are not tubercular, arranged in twenty-seven or twenty-nine rows. The color is yel- 

 lowish brown, and the back is ornamented by a series of about thirty distinct, dia- 

 mond-shaped spots, which are dark brown in color, with a lighter centre, and mar- 

 gined with yellow ; on the tail these spots pass into transverse bands. This species is 

 an inhabitant of the southern states, and its varieties extend to California and into 

 Mexico. In its habits the diamond-rattler prefers the damp and shady places in the 

 neighborhood of water, though there is no evidence that it follows its prey into that 



