BRANCH CHORD AT A : CLASS BATRACHIA 299 



larval condition, that is, while retaining the gills and a 

 compressed fin-like tail. In the case of a certain Mexican 

 species (A. maculatunt) it is believed that the final meta- 

 morphosis never occurs. The Mexicans call these gilled 

 larval Amblystoma axolotls, and use them for food. For 



FIG. 121. The Western brown eft, or salamander, Diemyctyhis torosus. 

 (From living specimen.) 



a long time naturalists supposed the Amblystoma larvae 

 which produce young to be the adults of a species of sala- 

 manders which retained their gills through life, like the 

 sirens and mud-puppies, and classified them in a distinct 

 genus. 



Of the various common salamanders or newts some are 

 found in streams, ponds, and ditches, and some under 

 logs and stones in the woods. The aquatic forms have 

 the tail compressed (flattened from side to side), while 

 the land forms have the tail cylindrical, tapering to a 

 point. Most of the land-salamanders produce their young 

 alive, while the water forms lay eggs which are usually 

 attached to a submerged plant-stem. The salamanders 

 are, almost without exception, found only in the northern 

 hemisphere. 



Frogs and toads (Anura). There are about a dozen 

 species of frogs in the United States. The largest of 

 these, and indeed the largest of all the frogs, is the well- 

 known bullfrog (Rana catesbiand], which reaches a length 

 (head to posterior end of body) of eight inches. It is 

 found in ponds and sluggish streams all over eastern 



