SALAMANDERS AND NEWTS. 



69 



Older II.— URODELA. 

 Salamandees and Newts. 



The members of this group, which are chiefly confined to the more 

 northern countries of the Northern 

 Hemisphere, are characterised by the -^'S- ^^• 



possession in the adult state of a tail 

 and at least the front pair of limbs, 

 whence they are termed Tailed Am- 

 phibians. Of the four families, the 

 Amphiumidd' and Salainanihi(l<r have 

 maxillary bones in the skull ; the 

 second of these families differing from 

 the first by the presence of movable 

 eyelids. The Froteidcp are distin- 

 guished from both the above by the 

 absence of maxillae, and the permanent 

 retention of external gills ; while the 

 Sirenidip, in which the gills are also 

 persistent, differ from all the rest by 

 the lack of hind-limbs. The larvte 

 are always aquatic, but the adults may 

 be terrestrial. Occasionally, as in the 

 Axolotls of Mexico, the larval condition 

 is permanent, although the reproductive 

 functions become fully developed. 



Among the members of the Am- 

 phiumidm, mention may first be made 

 of the Giant Salamanders, a group 

 which now contains only two species, 

 the North American " Hellbender '" 

 {Crypto'branchux alleghaniensis, 549) 

 and the Giant Salamander of Japan and 

 China {MegalobatrarJius maximus, 548), 

 the latter of which grows to a length of 

 5 feet, and differs from the former by 

 the absence of a gill-opening. It is 

 solely on this difference that the two 

 species are assigned to genera apart. 



A third species occurs in the Miocene Tertiary strata of Europe. 

 Both the living forms are carnivorous. The Japanese species lives 



The Three-toed Salamauder 

 (Amphiuma means). (No. 550-) 



