178 REPTILES. 



Tribe IV. Strobilosaura. 



Scales of the belly small, rhombic, imbricate, of the back and 

 sides imbricate. Tongue thick, short, convex, end slightly nicked. 

 Eyes diurnal, with valvular eyelids. Pupil round. Feet for walk- 

 ing. Toes unequal, compressed. Tail with more or less distinct 

 whorls of scales. 



Fam. XIX. The Iguanes, (Iguanid^). 



The teeth are round at the root, dilated and compressed at the 

 tip, toothed on the edge ; placed in a simple series on the inner 

 side of the jaws, just below the edge, and covered on the inner side 

 by the gums ; they are replaced by the young ones, which grow at 

 the base of the old ones, and gradually cause the absorption of 

 their roots. These animals are confined to the New World. 



The skull with a single principal frontal bone and two nasals, 

 the parietal hole is placed in the suture between the frontal and 

 parietal bones ; the palate generally with a series of teeth on the 

 pterygoids, (Cuv. Oss. Foss. v. t. 16, f. 23—25, t. 17, f. 4 & 34). 



I. Body compressed^ covered with rings of squarish small often 



keeled scales. Perchers. 



A. Nostril lateral^ heloiv the eye-ridge. Toes slender^ simple. Bach 

 not crested. Interparietal plate small. 



a. Throat compressed^ toothed in front. Third and fourth toes 

 nearly equal. Eyes prominent. 



1. PoLYCHRus. Femoral pores distinct. Scales of back and 



sides equal. 



2. Sph^rops. Femoral pores none. Scales of sides larger. 



b. Throat rounded^ ivith a cross fold behind. The fourth toe the 



longest. Femoral pores none. 



3. Urotrophus. Scales circular, smooth. Tail end revolute. 



4. Ecphymotes. Scales rhombic, keeled. Head 4-sided. 



5. LiEMANCTus. Scales rhombic, keeled. Head dilaled and 



rounded behind. 



