6'J 

 Lizards. 



Anolis. 

 Oligosoma. 



Snakes. 



Haldea. 



Ce7nop1iora. 



TantiUa. 



Spilotes. 

 Abastor. 

 Farancia. 

 Tortoises. 



Macroclielys. 



Crocodiles. 



Alligator. 



Batrachia. 



Engy stoma. 



Manculus. 



Stereochilus. 



3Iuraeno])sis. 



Siren. 



I have omitted from this list ten genera which are restricted to one or 

 the other of its subdivisions. The Siren, the CemopJiora, the Anolis 

 (chameleon), and the Alligator, are the most striking of the above char- 

 acteristic genera. No genus of lizards is peculiar excepting Anolis and 

 Oligosoma, which have their greatest development in other than the 

 Kearctic continent. Among serpents, a few genera of Neotropical char- 

 acter extend eastward along the region of the Mexican Gulf, as far as 

 the Atlantic coast, which are not found in any of the Northern re- 

 gions ; such are Spilotes, TantiUa (occurs in Lower California), and Elaps 

 (also in the Sonoran). On the other hand, Celuta, Virginia, Haldea, and 

 Storeria, embrace small serpents which it shares with the Eastern 

 region. 



This region is the headquarters of the Batrachia, especially of the 

 tailed forms. The majority of species of the tailless genera are found 

 here, especially of Hyla (tree-toads), Rana, and Chorophilus. 



