192 3. 1GUANID& 



gate, very low. Canthus rostralis well-marked. Nostrils 

 large, opening almost upward in rounded plates, much 

 nearer to end of snout than to orbit. Plates on head large, 

 smooth, and but slightly convexj irterparietal largest. 

 Frontal plate usually divided transversely. Two or three 

 posterior series of supraoculars enlarged, separated from 

 f rentals by one or two series of granules. Superciliaries long 

 and imbricate. A long, narrow, strongly-keeled subocular, 

 followed and preceded by similar but smaller plates. Rostral 

 very wide and low, as also the five or six supralabials. Sym- 

 physeal plate large and followed by several large chin- 

 shields. First infralabials much larger than others. Sub- 

 labials long and narrow. Skin on gular region covered 

 with small, smooth, rounded granules, slightly largest cen- 

 trally and near edge of strong gular fold. A dermal fold on 

 each side between limbs. Back and sides covered with smooth, 

 convex, rounded granules, largest medially, smallest later- 

 ally, and changing gradually to small, smooth, slightly im- 

 bricate scales on belly. Tail and anterior and upper surfaces 

 of limbs bearing larger imbricate scales each provided with a 

 strong keel ending in a projecting spine. Nineteen to 25 

 pores forming a series along each thigh. Males with en- 

 larged postanal plates. 



The color above is bluish gray or olive, strongly tinged 

 with brown on the head and tail, and crossed by irregularly 

 undulate bands of dark gray, brown, or slate. A narrow 

 straight band of intense black crosses from shoulder to shoul- 

 der over the back. The spaces between these bands are vari- 

 ously spotted, marbled and reticulated with lighter, and 

 thickly sprinkled with light blue dots. The limbs are irreg- 

 ularly cross-banded with dusky. The tail is pale brownish 

 olive with wide blackish or dark brown cross-bars; its proxi- 

 mal fourth often bluish on the lighter portions. The lower 

 surfaces are greenish white, suffused with deep indigo on 



