Art. VI.] Herrick-Terky-Herrick, Neza Mexico Lz^aj^ds. 139 
Description : Head and body depressed; head truncately 
pointed in front; head plates flat smooth; interparietal largest; 
frontal plate divided transversely, followed in a cephalic direc- 
tion by an irregular series of enlarged plates; three to five 
supraoculars enlarged and separated from the frontals by small 
granules; superciliaries imbricate, few, projecting; central sub- 
ocular large keeled; rostral and supralabials long and low; the 
other plates of the upper surface small or granular; symphyseal 
plate rather small, followed on either side by larger smooth 
plates which are separated from the infralabials by one to three 
series of sublabials; gular region covered with small, smooth, 
nonimbricating scales; gular fold with a series of projecting 
spines; tympanic opening with an armature of three enlarged 
spines; lateral dermal folds present; back with keeled scales 
hearly uniform in size but graduating into those of the side, 
on the neck and sides granular scales; scales of tail large, keeled 
and pointed; femoral pores from twelve to seventeen. 
Color : Upper parts with a ground color of brownish or 
yellowish gray densely spotted with darker and lighter; a more or 
less distinct light band on either side of the back, most distinct 
anteriorly; the small spots of the upper surface tend to be blue 
or green and often give to the animal a prevailing tone of that 
color; tail often with dark rings; upper surfaces of limbs spot- 
ted like the back; toes of hind feet with dark bands; under 
parts light, variously marbled with dark; throat blue with light 
spots; an irregular blue spot behind the fore leg which is sur- 
rounded by a light band; usually a brown spot in front of the 
shoulder; sides marked with large light spots. 
This graceful species is abundant in the Rio Grande valley 
at Socorro and further north. It is active and restricted to the 
ground. 
Genus. Crotophytus. 
Head and body depressed or sub-cylindrical, much shorter 
than the very slender tail; no dorsal crest; a gular fold; tym- 
panum present; all the head plates small; labials not imbricate; 
dorsal scales small and nearly uniform; a long series of femoral 
