CLASS REPTILIA. 



Smooth-headed Gerrhenote. Gerr. Leiocephalus, Weigm. 



Head smooth, scales four angular, in cross series, of middle 

 of back keeled, of nape and sides smooth; grey green, 

 bluish beneath, with nine longitudinal lines. Mexico. 



Toes 4, 4, femoral pores — Sauroiphis Fitz. Tetradactylus, 



Merrem. 



New Holland Saurophis. Saurophis Lacepedii, Lac. 

 Tetradactylus, Lacep. Ann. Mus. ij. t. 59. f. 2. Tetradac- 

 tylus ChalcidiceSf Merrem. 



Gen. II. Ophtsaurus. 

 Teeth on the side of the jaw ; legs rudimentary ; ears dis- 

 tinct ; lateral line distinct ; vent medial. 



a. Hinder extremities only rudimentary, on the side of the 



vent, undivided. Pseudopus, Merrem. 

 Pallas* s Scheltopusik. Pseu. Serpentinus, Merrem. Ps. Pal- 



lasii, Cuy. Lac. apoda, Pall. Nov. Com. xix. t. 9. 

 Scales smooth ; caudal scales square ; front feet rudi- 

 mentary, length two feet. Russia. 



Durville's Pseudopus. Pseutopus Durvillii, Cuv. 



Brown ; dorsal and caudal scales keeled, rough. Brit. Mus. 



6. Legs none. Ophisaurus, Daud. Hyalinus, Merrem. 



Common Glass Snake. O. Ventralis, Daud. Anguis, Linn. 



Yellow green, black spotted. Sometimes the spots form con- 

 tinued lines. Oph. Striatalus and Oph. Punctatus, Cuv. 

 MSS. differ very little, if at all, from this species. 



Gen. III. Chalides. 

 Teeth on the side of the jaws .'' Legs four, distinct ; ears hid 

 under the skin ; vent medial, linear. 



a. Toes 5, 5. Chalcides, Fitz. 

 Common Chalcides. 



Ferruginous with six dorsal lines. 



F 65 



