124 REPTILES AND BATRACHIANS 



Dorsal rows twenty-five ; ventrals one hundred and 

 seventy-three ; subcaudals twenty- three. Crown shields 

 rugose ; two triangular internasals ; two prefrontals ; four 

 frontals, forming a quadrangle, with a small scale in the 

 middle. About thirty-two lozenge-shaped blotches on the 

 back, each with yellow margins a single scale in width. 



CROTALUS PALMERI Vai\ U. 



Monclova, Mexico. 



Dorsal rows twenty-three ; ventrals one hundred and 

 sixty-four ; subcaudals twenty-four. Snout moderately 

 broad ; crown flat ; two internasals ; prefrontals in two 

 transverse series, anterior of five and posterior of four 

 scales; frontals small, smooth; supraciliaries prominent 

 laterally ; two anteorbitals, separated from the nasal by 

 two scales ; postorbitals three ; suborbitals two, posterior 

 separated from the labial by one scale, anterior in contact 

 with the fourth or fourth and fifth labials ; labials twelve ; 

 lower labials ten ; pit surrounded by three scales. 



The general appearance of the scales is as if they had 

 been polished, on head and body; the keels are low, and 

 are present on all except the outer row of each side. On 

 the back the color is bluish grey. With the lens the scales 

 are shown to be thickly puncticulate with darker. There 

 are no lines, spots or dots on head or neck. Farther back 

 a series of dark spots, of a couple of scales each, is faintly 

 visible on the outer two rows of the flank ; the spots grad- 

 ually become darker until in the posterior half or more of 

 the length they are black. Toward and on the tail the 

 spot lies at the extremity of a faintly defined transverse 

 band. Along the lower part of the side there are evidences 

 of a reddish tint in life. The belly is yellow, slightly 

 clouded or mottled with brownish. 



The specimen is only two feet six inches in total length ; 



