TOADS, FROGS AND SALAMANDERS 257 



and its tributaries. The salamanders and newts are common 

 in many regions. Most of them possess neither gills nor 

 gill openings in the adult. Some of them are often called 

 lizards, but they differ widely from the lizards in many re- 

 spects. The body is soft and not provided with scales, and in 

 their development they pass through a tadpole stage similar 

 to that of the frogs and toads. Amblystoma tigrinum is an 

 interesting and widely distributed common species. In 

 some regions the larval form, know r n as axolotl, reaches 

 a large size and produces young before completing the 

 usual metamorphosis. 



FIG. 117. A brown salamander, Notophthalmus lorosus. (Reduced.) 



The Frogs and Toads (order Anura). This is by far the 

 largest and most important order of Amphibia. There are 

 about a dozen species of frogs, family Ranidce, found in the 

 United States. The well known bullfrog, Rana catesbiana, 

 is the largest of these, attaining a length of seven or eight 

 inches. It occurs in ponds and sluggish streams all over the 

 eastern United States and in the Mississippi Valley. Frogs 

 are very commonly used as food in the United States but not 

 as extensively as in some of the European countries. The large 

 hind legs and "saddle" afford a considerable mass of very deli- 

 cately flavored meat. It has been pointed out that there is an 

 opportunity for the development of a small but profitable 

 industry in raising frogs for market in some of the extensive 



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