234 IGUANID.^. 



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. 



18. Sceloporus scalaris. 



Tropidolepis scalaris, Gray, Cat. p. 210. 

 Sceloporus scalaris, Wiegm. Isis, 1828, p. 870, (ind Herp. Mex. p. 50, 



pi. viii. fig. 2; Bocourt, Miss. Sc. Mex., Rept. p. 202, pi. xviii. bis. 



tig. 9 ; Cope, Proc. Am. Philos. Soc. xxii. 18So, p. .394. 

 Tropidolepis scalaris, Gray, Zool. Beeeheifs Toy. p. 95, pi. xxx. fig. 3 ; 



Dum. 8f 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 axUla 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 jiores 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 



