FISHES, BATRACHMNS, AND REPTILES 



215 



makes its owner formidable among tlie small sardines 

 and herring-like fishes on which it feeds. The sawfishes 

 live in tropical rivers, descending to the sea. 



Fig. 174. — The common skate, Kaja i:rinact!a. (From Kingsley.) 



Baskett's " Story of the Fishes, " McCarthy's "Famil- 

 iar Fish," and Jordan and Evermann's " Food and Game 

 Fishes of America ' ' are good books for elementary stu- 

 dents of fishes. 



The batrachians.^ — ^We have made the acquaintance 

 of the most familiar batrachians in our study of the 

 life-history of the toad and frog (Chapter II). Other 

 familiar members of this class are the salamanders. 

 All batrachians breathe by means of gills for a longer 

 or shorter time after birth. But except in very few 

 cases these gills are lost and lungs developed so that 



