Soiitliern Neotropical realms. But one mammal (the cougar, Fclis con- 

 color), aud no reptiles, batrachians, nor fresh-water fishes, extend into 

 Brazil ; but a number of birds are permanent residents throughout both 

 realms. These are mostly waders, as follows: 



Rallus crepitans. 

 Limosa fedoa. 

 Tryngites rufescens. 

 Actiturus hartrmnius. 

 Heteroscelus hreripes, 

 Symphemia scmipalmata, 

 Ereunetcs petrijicatus. 

 Aegialitis Tilsonius. 

 Xycth crodius r io la ce us. 



To these must be added the turkey-vulture, Cathartes aura. Then 

 certain marine birds aud a few fishes extend along the coasts of both 

 regions, but their number is comparatively small. 



The number of species of the Is^earctic realm which occur in the Mex- 

 ican region is rather greater. The red lynx and raccoon are examples 

 of mammals, and several species of wood- warblers, vireos, and hawks 

 represent the birds as far south as the Isthmus of Darien. The only 

 reptiles are the snapping-tortoise and tbe ringed snake Ophibolus dolia- 

 ills ; the only batrachian is the Rana halecina bcrlandieri. A few other 

 species, as Eutaenia sirtalis, extend for a shorter distance into the same 

 region. 



In the higher groups of the genus and family, we have greater com- 

 inunity with the Neotropical realm. But few genera of Batraclda and 

 lieptUia extend to its Brazilian region, but there are a few common 

 genera of JitammaUa {Mej)hitis, Procyon, Ursus, Scinrm, Ilespcromys, aud 

 Dklelphys), and a number of birds, especially among the lower orders, and 

 tbe scansores, syndactyli, aud clamatores, particularly the Tyrannidae. 

 Tbe number of genera which enter INIexico and Central America is much 

 greater, and I select the following from the mammals, reptiles, aud 

 batrachians as these are incapable of the migrations performed by birds. 

 Cosmopolitan genera and those common to both the American realms 

 are omitted. 

 5 II 



