CHAPTER V 



LISSAMPHIBIA (CONTINUED) UEODELA 



Order II. URODELA or TAILED AMPHIBIA. 



THE recent tailed Amphibia, Salamanders and Newts in the wider 

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

 veniently diagnosed by the following characters : 



Both the upper and lower jaws are furnished with teeth. Fore- and hind- 

 limbs are always present. 

 Maxillary bones present. 



Eyes free and devoid of lids . . AMPHIUMIDAE, p. 97. 



Eyes with movable lids 1 . . SALAMANDRIDAE, p. 102. 



Maxillary bones absent. 



Eyes without lids. Perennibranchiate PROTEIDAE, p. 132. 

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

 are absent. Perennibranchiate . . SIRENIDAE, p. 136. 



These four families are closely allied to each other, especially the 

 Amphiumidae and the Salamandridae. 



The geographical distribution of the Urodela is essentially 

 Periarctic, except that about one dozen species each of Amblystoma 

 and of Spelcrpes extend southwards into Central America, and in 

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

 South America. Plethodon platense inhabits Argentina. 



The .Urodela afford good reasons for dividing the Periarctic 

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

 Eastern 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 very poor in Urodele forms ; while, lastly. 



1 The existence of such a form as Typhlotriton, in the adult of which the eyes 

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

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



