_Description._--Head and body little depressed; nostril opening much nearer to end of snout than to orbit; upper head shields smooth, moderately large and slightly convex, interparietal largest; frontal divided transversely; parietal and frontal plates separated from enlarged supraoculars by a series of small plates or granules; frontoparietal in contact with enlarged supraoculars; superciliaries long and strongly imbricate; middle subocular very long, narrow and strongly keeled; rostral plate of moderate height but great width; labials long, low and nearly rectangular; symphyseal large and pentangular; some series of enlarged sublabials; gulars smooth, imbricate, often emarginate posteriorly; ear-opening large, slightly oblique, with anterior denticulation of smooth acuminate scales; scales on back equal-sized, keeled, mucronate with slight denticulation, and arranged in nearly parallel longitudinal rows; lateral scales smaller and directed obliquely upward; upper and anterior surfaces of limbs with strongly keeled and mucronate scales; posterior surface of thigh with small, acuminate, keeled scales; ventral scales much smaller than dorsals, smooth, imbricate, and usually bicuspid; tail furnished with slightly irregular whorls of strongly keeled and pointed scales which are much larger and rougher above than below, where they are smooth proximally; femoral pores 14-16; 9-12 dorsal scales equaling length of shielded part of head; number of scales in a row between interparietal plate and a line connecting posterior surfaces of thighs varying from 43-48; males with enlarged postanal plates. The color above is grayish, brownish, or greenish blue, with a series of dark brown blotches on each side of the back. A pale longitudinal band separates the dorsal from the lateral regions. The sides are brownish or grayish, mottled with darker brown and dotted or suffused with green or pale blue. The head is usually crossed by narrow brown lines, more or less irregular in distribution. A brown line connects the orbit and upper corner of the ear, and is continued backward on the neck. There is a large blue patch on each side of the belly, bordered internally with black in highly colored males. The chin and throat are blue, pale anteriorly and changing to black posteriorly, crossed by narrow oblique black lines which converge posteriorly and blend with the black patches on the throat and in front of the shoulders in males. There is a white patch at each side of the anus, and a yellowish white band along the series of femoral pores.