IGUANID.K. 37 



medium to large specimens with three pairs of ridges on 

 the top, concave on forehead and occiput, longer than the 

 tibia; snout depressed ; prefrontal ridges low, forming an 

 acute angle between the nostrils, not meeting the supra- 

 orbitals ; upper head scales rough ; scales of the supraor- 

 bital semicircles enlarged, separated from each other by 

 two (one to three) series and from the occipital by one 

 series of small scales ; occipital twice as large as the ear 

 opening; eight to twelve enlarged, keeled supraoculars, 

 separated from the supraorbitals by one row of granules ; 

 rostral canthus sharp, of four scales ; loreal rows four to 

 live ; five to six labials to below the centre of the eye ; 

 ear opening small, vertical diameter largest. Gular ap- 

 pendages large, smaller in the female, scales indistinctly 

 keeled. A dorso-nuchal fold. Dorsal scales keeled, small, 

 larger at the sides of the two rows of large, compressed, 

 elongate, keeled scales forming the crest on the fold, 

 smaller on the flanks ; ventrals carinate, larger than the 

 dorsals, excepting the crest ; antefemorals keeled, little 

 larger than the ventrals, if we except a couple of scales 

 immediately on the knee. Limbs long, the adpressed 

 hind leg reaches in front of the eye ; digital expansion 

 moderate, about twenty-nine lamellae under phalanges ii 

 and iii of the fourth toe. Tail compressed, with a crest 

 in which the large scales are nearly equal, close upon two 

 and a half times as long as both head and body. 



Grayish to brownish or olivaceous, clouded, freckled, or 

 spotted with brown and white. Sometimes with a few- 

 rounded spots of black about the shoulders ; in such cases 

 the spots are arranged in series which descend backward 

 from the crest. Many have an indistinct brownish band 

 across the shoulders, the middle of the body, the femur 

 and the tibia; they also have bands across the digits and 



