6. CROTAPHYTUS 119 



oculars and temporals granular, as also gulars. Lower 

 labials slightly larger than upper, and bordered below by 

 several series of small plates larger than gulars. Symphy- 

 seal plate very large, but shields behind it not so large as in 

 C. c. baileyi. From one to three transverse gular folds, 

 only one well-developed. Back and sides covered with 

 small granules, largest centrally, and passing gradually into 

 the larger scales on the belly. Latter imbricate and some- 

 times keeled. Irregular dermal folds usually present on 

 sides. Tail conical, a little more than twice length of head 

 and body, and covered with whorls of small scales. Femoral 

 pores varying in number from about 14 to 25. Males with 

 enlarged postanal plates. 



In the young the head is dark brown above, with cream- 

 colored lines surrounding the orbits and supraocular regions 

 and running up the median line of the snout from the 

 rostral plate. The back is grayish brown with white or 

 cream-colored cross-lines, which may either meet or alter- 

 nate, on the median line, with those of the opposite side. 

 Between each pair of these cross-lines is a round spot of 

 dark brown. The tail is marked like the back, but not so 

 regularly. The limbs are brown with irregular spots and 

 lines of white. The lower surfaces are yellowish white, 

 marked on the throat with longitudinal lines of dark brown. 

 As the animals become larger the brown dorsal spots become 

 smaller and more numerous, so that there are several between 

 each pair of light cross-lines. The whole coloration becomes 

 paler, as if faded, and the pattern less distinct. Usually 

 the light cross-lines fade first, leaving the spots fairly dis- 

 tinct, but the reverse order of disappearance may occur. In 

 some very old specimens the cross-lines have entirely van- 

 ished and the brown spots have become very minute. There 

 is also a good deal of purely individual color variation. 



