94 



CLASSIFICATION OF AMPHIBIANS. 



Menopoma and Amphiuma, both peculiar to North 

 America. The first consists but of a single species^ 

 called the great American salamander, which attains 

 the length of eighteen inches. In addition to the 

 usual range of teeth in the jawS;, it has another parallel 

 row on the front of the palate. We owe to Dr. Harlan, 

 the most eminent of all the American ei-petologists, a 

 highly valuable account of this singular animal. Dr. 

 Garden, another observing naturalist of the Western 

 "^T'^orld, discovered the genus Amphiuma, a peculiarly 

 interesting group, as showing a strong relation between 

 the salamanders to the sirens. There are two species 

 {Amph. tridactylum (^fig. 26.) and means), differing only 



in size and the number of their toes. Both have a 

 very long body, giving them the appearance of eels, 

 while their legs and feet are so very short and sliglitiy 

 developed, that they appear useless. 



{99') The trae Amphibia are those which breathe not 

 only by lungs but by gills, the latter being always re- 

 tained as peiTQanent and essential members during the 

 Avhole of life, and not cast off, as in the salamanders, so 

 soon as the animal arrives at maturity. Of these 

 animals M. Cuvier justly and truly observes that " they 

 alone must be regarded as the only vertebrated animals 

 which are truly amphibious," and hence we have 

 always had a strong suspicion that they constituted the 

 t^-pical perfection of this class. The leading genera 

 are four. : — Phylhydrus (formerly denominated by Shaw, 

 Siren pisciformis) ; 2. Menohranchus ; 3. Proteus ; 

 and 4. Siren. As a mere technical description of the 

 external characters of these remarkable animals would 



