234 IGUANIDE. 
a little smaller than dorsals. Male with enlarged postanal scales. 
Metallic green or coppery above, usually with one or two lighter 
dorso-lateral bands on each side, with or without four longitudinal 
series of transverse dark-brown spots; a blackish spot in front of 
the shoulder; lower surfaces greenish white in the female, the 
throat and breast mottled with grey ; in the male, the throat, breast, 
and belly entirely blackish-blue, or largely and closely marbled with 
blackish-blue. 
millim. millim. 
Total length ...... 135 Fore limb........ 21 
Gad ee tuostte le sit 14 Hind limb........ 33 
Width of head .... 12 alle waaneieactaras 7O 
Body sce en esac 46 
Mexico. 
a-b, c-d. 5 Q. Puebla. 
e @. Orizaba. 
tg. 2. Mexico. 
18. Sceloporus scalaris. 
Tropidolepis scalaris, Gray, Cat. p. 210. 
Sceloporus scalaris, Wiegm. Isis, 1828, p. 370, and Herp. Mex. p. 50, 
pl. vill. fig. 2; Bocourt, Miss. Sc. Mex., Rept. p. 202, pl. xviii. bis. 
fic. 9; Cope, Proce. Am. Philos, Soc. xxii. 1835, p. 394. 
Tropidolepis scalaris, Gray, Zool. Beechey’s Voy. p. 95, pl. xxx. fig. 3 ; 
Dum. § Bibr. iv. p. 310. 
Head-shields keeled or striated; a more or less regular series of 
transversely dilated supraoculars; two canthal scales; occipital as 
long as broad, or a little longer than broad; parietals very small ; 
anterior border of ear very slightly denticulated. Dorsal scales 
larger than ventrals, strongly keeled, sharply pointed, forming 
parallel longitudinal series ; forty-three to forty-eight scales between 
the occipital and the base of the tail; seven to ten scales correspond 
to the length of the shielded part of the head; lateral scales nearly 
as large as dorsals, more or less distinctly keeled, forming straight 
longitudinal series ; ventrals smooth, mostly bicuspid ; thirty-eight 
to forty-six scales round the middle of the body. The adpressed 
hind limb reaches the axilla or the shoulder in the female, between 
the shoulder and the ear in the male; tibia usually a little longer 
than the shielded part of the head; the distance between the base 
of the fifth toe and the extremity of the fourth exceeds the distance 
between the end of the snout and the posterior border of the ear, 
Sixteen to nineteen femoral pores on each side, the two series meet- 
ing medially. Caudal scales as large as or larger than dorsals. 
Male with enlarged postanal scales. Yellowish brown or olive above, 
with four regular series of large crescentic brown spots, the series 
separated by more or less well-defined light longitudinal lines; head 
with symmetrical dark-brown markings; a black or deep-blue spot 
in front of the arm; lower surfaces yellowish white, the throat 
