43. cROTAPHYTUS. 203 
43. CROTAPHYTUS*. 
Crotaphytus, Holbr. N. Amer. Herp.ii.p.79; Baird & Gir. in Stansd. 
Exped. Gr. Salt Lake, p. 339; Bocourt, Miss, Sc. Mex., Rept. p. 153. 
Leiosaurus, part., 4. Dum. Arch. Mus. viii. p. 532, 
Tympanum distinct. Body depressed; no dorsal crest; dorsal 
scales small, Upper head-scales small. A transverse gular fold; 
no gular pouch. Digits with sharply keeled lamellx inferiorly. 
A long series of femoral pores. Tail long, cylindrical. Lateral 
teeth tricuspid; pterygoid teeth. No sternal fontanelle. No ab- 
dominal ribs. 
Southern North America. 
1. Crotaphytus collaris. 
Agama collaris, Say, in Long’s Exped. Rocky Mount. ii. p. 262; 
Harlan, Med. Phys. Res. p. 142, pl. —. tig. 4. 
Crotaphytus collaris, Holbr. lc. pl. x.; Wied, Nov. Act. Ac. Leop.- 
Car, xxxil. 1865, p. 58; Baad, Tep. US. Expl. Surv. xiii. pt. iii. 
p. 17, pl. xxiv. fig. 1; Cope, Proc. Ac. Philad. 1866, p. 302; 
Bocourt, l. ce. p. 154, pl. xvii. bis. figs. 5, 6. 
Leiosaurus collaris, 4. Dum. 1. ¢. 
Head large, much depressed, very distinct from neck, especially 
in the males, in which it bears resemblance to that of Gecko verti- 
cillatus; nostril large, turned upwards and outwards, a little nearer 
the end of the snout than the orbit; ear-opening large, vertically 
reniform ; scales on the snout a little enlarged, irregular, convex ; a 
series of enlarged supraorbital scales, in contact or fusing with each 
other between the orbits; supraocular scales small; back of the 
head with small granules; occipital not enlarged; labials very 
small; a serics of enlarged infraorbital scales, very variable in 
number and in size, the median one sometimes much elongate, 
owing to the fusion of two or three scales. Throat covered with 
small granules, which are slightly enlarged and flat in front of the 
gular told. Sides of the neck strongly plicate. Dorsal scales uni- 
form small. juxtaposed granules ; ventral scales larger, flat, hexa- 
gonal. Limbs long; the adpressed hind limb reaches the eye or the 
tip of the snout; digits rather long. Seventeen to twenty femoral 
pores on each side. Tail slender, cylindrical, nearly twice as long 
as head and body, covered with uniform, small, smooth or feebly 
keeled scales. Brownish or olive above, back guttate with whitish ; 
two parallel oblique black bands on each side across scapular region, 
usually separated on the median line of the nape; lower surfaces 
white; throat frequently spotted with grey. 
+ Crotaphytus reticulatus Baird, Prce. Ac. Philad. 1858, p. 253.—Texas. 
Crotaphytus copeit, Yarrow, Proc. U.S, Nat. Mus. v. 1882, p. 441.— 
La Paz, Oalifornia. 
