CROCODILIANS, LIZARDS, AND SNAKES. 



1177 



Scales in front of the snperciliaries variable. Tn one Sjx'cinien there are 

 two rows of four each, of considerable size; in another they are larger 

 than the rest, but irregular. Scales on the cheeks large, flat, smooth. 

 Ground color, light brown above. Along the back a series of sub- 

 hexagonal or octagonal blotches, formed by a skeleton of dull yellowish, 

 constituting a dorsal chain. The space thus inclosed of the ground- 

 color is margined faintly with dark brown. The width of the interval 

 between the sut-cessive blotches is from one-half to one and a half 

 scales. These spots are frequently confluent, two and three running 

 together. Where most distinct the s])ots are four scales long and 

 eleven wide. On each side of this dorsal series is a second, separated 

 by a single row of scales, the blotches extending from the abdominal 

 scutellse to the fifth or sixth row. These are smaller than the dorsal 



Fig. 339. 

 CROTALUS rONPLUENTUS LUCIFER BAIRD AND GiRARD. 



:-: 1. 



San Francisco, ("alilbrniii. 



and subcircular. ()))posite the transverse light bands, and in the open 

 space between four contiguous blotches on the sides, smaller blotches 

 are indistinctly visible. Posteriorly the s])ots on the back and sides 

 are confluent and darker, in one specimen forming seventeen half rings, 

 encircling the back, leaving about twenty-four dorsal blotches. Abdo- 

 men greenish yellow, more or less clouded with brown at the bases of 

 the scales. Head dark brown; alight line from posterior ])ortion of 

 the snperciliaries along the fourth row of supralabial scales back to the 

 angle of the jaws, on the occiput, where it expands into the color of 

 the under part. Upper labials of the same light color behind, rapidly 

 widening anteriorly so as to include whole front and side of the face, 

 leaving only the top of the head dark. The space about the facial pit 

 darker. 



