46 REPTILES, 



10. Caitia. Feet undivided, front very slender, elongated, hinder 

 compressed, thick. Body and tail elongate. Femoral pores 2-2. 



c. Tail unarmed. Head pp-amidical, elongate. Collar distinct^ 

 of keeled scales. Inguinal pores 2-2. 



11. Tachydromus. Ventral shields keeled. Throat with keeled 

 scales. 



12. Tachysaurus. Ventral shields smooth. Throat granular in 



front. 



o' 



B. Femoral pores none. Nasal plates ivith 2 or more pairs of supra- 

 nasal shields above. Occipital plates numerous. Collar none. 

 Throat shielded. 



a. Limbs 4. Body fusiform. Tongue velvety. Western hemisphere. 



13. Abronia. Head depressed. Inter-nasals small, distinct. 

 Scales of back smooth. 



14. Gerrhonotus. Head pyramidical. Internasal small, su- 

 pranasal large. Scales of the back keeled. * 



15. Elgaria. Head pyramidical. Internasal large, supernasal 

 very narrow. Scales of the back keeled, of sides smooth. Tail 

 elongate, slender. 



16. Barissia. Head pyramidical. Internasal plates none. Scales 

 of back keeled. . . 



b. Legs 2 or none. Body snake-like. 



17. PsEUDOPus. Limbs 2, posterior, undivided. 



18. Ophisaurus. Limbs none. 



A. Femoral pores distinct. Supranasal shields none or only 1 pair. 

 Occipital shields few. Legs 4. Eastern World. 



a. Tail spinose. Head depressed, broad. Fr onto. parietal and pari- 

 etal plates large. Tongue velvet-like. Collar none, or only a 

 slight fold on each side of throat. Nostrils in a single plate. 

 Femoral po res numerous . Z o n ur i n a. 



1. Cordylds. Zonurus, § ii. Gray. Dum. et Bib. 



Head depressed, fronto-parietal and parietal plates forming a 

 square. Temple-shield keeled ; nasal small, oblong ; supranasal 

 large, square, contiguous. Eyelids distinct, lower with a central 

 transparent smooth spot. Scales of the back moderate, rhombic, 

 keeled, striated and pierced with a pore, in close cross rows ; of 

 the back unarmed. Toes 5-5, compressed, keeled beneath. Tail 

 spinose, squarish. 



