238 Aquatic Organisms 



in frogs than in any other vertebrates, involving 

 profound changes in internal organs and in manner of 

 life. 



The reptiles are mainly terrestrial. Southward there 

 are alligators in the water, but in our latitude there are 



FIG. 145. The common snapping turtle. 



only a few turtles and water snakes. These make their 

 nests on land. They hide their eggs in the sand or in 

 the midst of marshland rubbish, where the sun's 

 warmth incubates them. 



These also are carnivorous. 



