70 



There are no less than nine genera cf birds which do not, or only 

 accidentally, range northward of this district. They are — 



Plotus. 

 Tantalus. 

 Platalea. 

 Elanus. 

 Ictinia. 

 Conurus. 

 Chamaejyelia. 

 Campephihis. 

 Helmitlierus. 



All these genera, excepting the last, range into South America or 

 farther. 



Among mammals, but few species and one genus {Sigmodon) are 

 confined to it. Lepus aquaticus and L. palustris^ the cotton-rat, the 

 Florida yeotoma, etc., and a few others, are restricted by it. The fish- 

 fauna is very similar to that of the Eastern region, under which it 

 will be considered. 



The Uasiern region differs from the Austroriparian almost entirely 

 in what it lacks, and agrees with it in all those peculiarities by which it 

 is so widely separated from the Central region. No genus of mam- 

 mals is found in it which does not range into the Central or other 

 region, excepting Condylura (star-nosed mole) ; but numerous species 

 are confined to it, not extending into the Austroriparian. These number 

 from twenty to twenty-five. Among birds, the following genera are shared 

 with the more southern region only : Qidscalus, Seiurus, Oporornis, 

 HelmithcruSj Frotonotaria. Panda, Mniotilta, Ortyx. No genus of Bep- 

 tiles, and but one of Batrachiaus [GyrinopMlus), is confined to this 

 region ; but it shares all it possesses with the Austroriparian. It 

 has but three genera of lizards, viz, Cnemidophorus, Eiimeces, and Scelo- 

 porus, which are universally Nearctic. The Batrachian genera not found 



in the Central are — 



SeapMopus. 



Gyrinophihis. 



Spelerpes. 



PJethodon. 



Hemidacty liu m. 



IJesmatognathns. 



Menopoma. 



J^ccturus. 



