_Description._--Body long and rather slender, with short limbs and very long tail; head pointed with flat top and nearly vertical sides, its temporal regions often greatly swollen in old specimens; rostral plate rounded in upper outline; on top of head behind rostral a pair of small internasals, a pair of small frontonasals, a very large azygous prefrontal, a pair of large prefrontals, a long frontal, a pair of frontoparietals, 2 parietals separated by an interparietal, a pair of occipitals, and an interoccipital; 2 series (of 5 and 3) supraoculars and a series of small superciliaries; temporal scales keeled, lower sometimes only weakly; upper labials much larger than lower; 2 series of large sublabial plates below infralabials, lower larger; gular scales smooth and imbricate; scales on arm and forearm keeled; scales on upper surfaces and sides of neck, body and tail large, rhomboidal, slightly oblique, strongly keeled, strengthened with bony plates, and arranged in both transverse and longitudinal series; number of longitudinal dorsal series 12-2/2-14; number of transverse series between interoccipital plate and backs of thighs 42-43; a band of granules along each side from large ear-opening to anus, usually hidden by a strong fold; ventral plates about size of dorsals, smooth, imbricate and arranged in 12 longitudinal series; number of scales between symphyseal plate and anus 60-63. The ground color above is olive-brown, more grayish on the sides, crossed by from 9-11 dark bands. These dark bands may be brown or brownish black, continuous or broken, and are darker laterally, where their scales are tipped with white. Tail proximally marked like back, distally unicolor. Head and limbs unicolor or with traces of olive-brown mottlings. Lower surfaces suffused with gray, edges of scales lighter, darker gray or slate-colored lines along the middle of each longitudinal scale row. Length to anus 103 110 117[8] Length of tail 167 128[2] 125[9] Snout to ear 21 25 26 Width of head 14 19 20 Head to interoccipital 17 20 21 Fore limb 27 30 33 Hind limb 34 38 41 Base of fifth to end of fourth toe 11 12 13 [Footnote 8: Type.] [Footnote 9: Reproduced.]