CHAPTEK V 



LISSAMPHIBIA {(JOXTINUED) — URODELA 



Order II. URODELA or TAILED AMPHIBIA. 



The recent tailed Amphiljia, Salamanders and Xewts in the wider 

 sense, have been grouped into four families which can be con- 

 veniently diagnosed by the following characters : — 



Both the ii])per and lower jaws are furiii^lied with teeth. Fore- ami hiud- 

 liiubs are alway.s present. 

 Maxillary bones present. 



Eyes free and devoid of lids . Amphiumidae, ]>. !)7. 



Eyes with movable lids^ . . Salamanuridak, ]>. 102. 



Maxillary bones absent. 



Eyes without lids. Perennibrancliiate Proteidae, p. 13:2. 

 Both jaws are toothless. The hind-limbs, the maxillary bones ami eyelids 

 are al)sent. P(>rennibranchiate . . Sirenidae, p. \'M\. 



The.se four families are closely allied to each other, especially the 

 Amphiumidae and the Salamandridae. 



The geographical distribution of the Urodela is essentially 

 l*eriarctic, except that about one dozen species each of Aviblystoma 

 and of i^pelerpes extend southwards into Central America, and in 

 the case of the latter genus even into the Andesian parts of 

 Siiuth .Vmcrica. PlrflKx/on jjlatense inhabits Argentina. 



The Urodela afford good reasons for dividing the Periarctic 

 region into three co-ordinate sub-regions, namely, Xearctic, 

 Rastern and Western Palaearctic. The difference between the 

 European and the Eastern Asiatic fauna is well marked : the two 

 are — at least with our present knowledge — separated by a wide 

 stretch of country vety poor in I'rodele forms; while, lastly. 



^ Tlie existence of such a f'oiiii as Tt/phhtriton, in the adult of whicli the eyes 

 become closed up, makes such .short diagnoses of the families defective, although 

 there is no doubt about the Desmognathine ;dtinitios of this genus. See p. 103; 



