63 



Tilt) Nearctic renlm poaaosses a peculiar family, the Cathartidae 

 (turkey-buzzards), which the Old World lacks, but has uo vultures 

 properly socuUed, 



There are several wadiug-blrds common to the two continents ; and 

 cases of identity among the ducks, gulls, and divers are relatively still 

 more numerous. The (lallinae are, on the other hand, entirely distinct, 

 thou{?li not without a few corresponding species. 



Among lower Vortebrata, specific identity is unknown, except in one 

 frog {liana temporaria) and a few marine fishes, with one of fresh-water, 

 the northern pike {Esox lucim). The numerous tortoises of North 

 America remind one especially of Eastern Asia and India, but the 

 western regions of our continent are as deficient in this form of animal 

 life as the corresponding part of the Palaearctic region. Chelydra is 

 peculiarly North American, and the CinostcrnUJae are Mexican in 

 character. 



The principal Crocodilian is our alligator, which presents only minor 

 (liU'erences from the South American caimans. The lizards are all 

 of Neotropical families, except the seines {Eiimcces), which are found 

 elsewhere chiefly in Africa and Australia. The genera are nearly all 

 peculiar, or extend a short distance into the northern parts of the Neo- 

 tropical, ilexico, and the West Indies. Some families have, however, a 

 correspondence with those of the Old World, as follows : The Nearctic — 



Teiidae to Lacertidae ; 

 Gerrhouotidae to Zontiiidae; 

 Iguanidae to Agamidae. 

 The Batradila present relations to the Europeo- Asiatic fauna iu the 

 •species of one genus {Rana) oi frogs, and one genus {yotophthalimis) 

 lof salamanders. In other respects, the Nearctic batrachiau fauna is 

 [highly peculiar. The cosmopolitan genus Uyla (tree-frogs) exists in 

 Immierous species, several of which are terrestrial. The burrowing-frogs 

 hScaphiojnclae) are nearly all peculiar to this faima. The toads are 

 lof a peculiar division of the all but cosmopolitan genus Biifo. The 

 jsalamanders present the greatest peculiarities. The large family of 

 ^ktJiodontidae is represented by various forms, mostly terrestrial ; while 

 the genera Besmognatlius and Amhhjstoma, each alone in its family, 

 present curious structural modifications. To the latter belong the Sire- 

 Ions, or larval Amblystomae, which reproduce without regard to their 

 letamorphosis, sometimes completing it and sometimes remaining 

 unchanged. 



