1208 REPORT OF NATIONAL MUSEUM, 1898. 



ix'cnliar species will be eniinierated later. Several species of mammals 

 are coiiMued to tliis subrejiiioii. The genera of birds that do not rauge 

 north of it are, according to Allen: 



Certhiola. Aramus i 



Zenaida ■\ Auduhonia ] 



Oreopelia \ Pigeons. Phmnicopterus. 



IStartiOBiias Haliplami > ^ 



> -Lerns 

 Rostrhamus i , Anoiis j 



,, , , Kaptores 



The isolation of the Floridan subregion is due to the fact that the 

 nucleus of the peninsula (which is of Eocene age) was separated from 

 the continent during the greater part of Neocene time. If at any time 

 connected with the Antilles, the period was of short duration. 



The Austroriparian subregion possesses many peculiar genera of rep- 

 tiles not found elsewhere, while the region north of it possesses none, 

 its genera being distributed over some or all of the remainiiig regions. 

 The number of peculiar species in all departments of animal life is 

 large. It presents the greatest development of the eastern reptile life. 

 Sixteen genera of Iveptiles and eight of Batrachia do not range to the 

 northward, Avhile ninety-nine species are restricted in the same man- 

 ner. The peculiar genera which occur over most of its area are: 



Saukia. Testudinata, 



Anolis. ' Macrochelys. 



Serpentes. Loricata. 



Elaps. Alligator. 



Haldea. Batrachia. 



Gemophora. IJngystoma. 



Tantilla. Maneulus. 



Compsosoma. Amphiuma. 



Farancia. Siren. 



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

 or the other of its subdivisions. Siren, Gemophora, Anolis, and Alli- 

 gator are the most striking of the above characteristic genera. No 

 genus of lizards is peculiar excepting Anolis, which has its greatest 

 development in other than the Nearctic continent. Among serpents 

 a few genera of Neotropical character extend eastward along the 

 region of the Mexican Gulf, as far as the Atlantic coast, which are 

 not found in any of the northern regions; such are Gompsosoma (Cen- 

 tral American), Tantilla, and Elaps (Sonoran). On the other hand, 

 Ahastor, Virginia, Haldea, ami Storeria embrace serpents which it shares 

 with the Eastern region. 



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



