OF IHE BAIKACHTA. 113 



CAUDATA. 



Salamand/rida. Number of Species. 



SalamandrincB. 



Tylototriton* 1 



Ambh/stomatinis. 

 Amblystoma 1 



APODA. 



Cmailiidce. 



Iclithyopliis * 2 



UrsBotyphlus 2 



GegeneopUs * 1 



5. The Teopical-Ameeican Eegion. 



The Tropical- American Eegion comprises the whole of South 

 America, Central America to the limits of the North-American 

 Eegion, and the West Indies. It exceeds every other Eegion with 

 regard to the number of families, genera, and species, the total 

 number of the latter being about four ninths of all those actually 

 known. 



The Eeaudata are represented by : — very numerous Oystignathidm 

 and HylidcB, these two families alone equalling in number a^. the 

 rest ; numerous Bufonidm and Engystomatidm ; few Banidce, a few 

 of which only belong to the genus Bana ; the DendrobMidae, the 

 second genus of which inhabits Madagascar ; the Dendrophryniscidce, 

 Anvphignathodontidm, and HemvphractidcB, three small families con- 

 fined to this region ; and, finally, the PipidcB, which, with the African 

 DaetyleihridcB, constitute the suborder Aglossa. 



A small number of Caudata, belonging to the genus Spelerpes, 

 inhabit Central America — two species, favoured by altitude, extend- 

 ing southwards to Colombia, and a third reaching a few degrees 

 south of the equator. A species of the same genus has also been 

 recently described from the West Indies. But the most extraordi- 

 nary instance of geographical distribution, if it be confirmed, will 

 be the presence in the valley of the Plate river of a species of 

 Pleihodon extremely closely allied to the Californian forms. 



The Apoda are represented by 6 genera and 21 species. Out of 

 these 6 genera, 5 are peculiar to the region ; the other, curiously 

 enough, it has in common with West Africa. 



The striking character of this region is the great proportion 

 (224 : 38) oiArdfera, and especially of Cystignathidce and Hylidce, it 

 in this respect resembling the Australian region. Its afiinities with 

 the Indian and African regions are shown by the development of 

 EngystomatidcE, and with the latter region particularly by the pre- 

 sence of Aglossa, Dendrobatidm, and the Apodal genus DermopMs. 

 As to its affinities with the North-American region, it is well 

 known that one fauna passes gradually into the other ; but if we 

 compare the fauna of the United States with that of South America, 

 the difference between them is as great as between those of any 

 other two Eegions, Africa and Australia excepted. 



■>v 



