CHi^PTER IX 



WHEEL ANIMALCULES 



Rotifera 



Rotifers are transparent microscopic animals which live in 

 fresh or salt water. They abound in the surface waters of 

 great lakes, and swarm through the shallows of ponds and 

 bogs; there is scarcely any stand of soft water, whether 

 transient puddle or rain-barrel or fountain-basin, where 

 rotifers can not be found. They live in ponds and lakes, 

 pro"vading a large part of the food for small crustaceans 

 and worms and are thus indirectly a main source of food for 

 fishes. 



Fig. I go. — Common rotifers: i, Philodina; 2, 

 Diglena, which sucks out plant cells; 3, Euchlanis, 

 showing shell-like lorica. (From Ward and 

 Whipple.) 



127 



