FRESH-WATER RHIZOPOD8. 



167 



FIG. 86. Group of common fresh-water Rhizopods (after Leidy) . A, Actinophrys 

 sol, the "sun-animalcule," filled with vacuoles and containing three food-bodies 

 (zoospores of an alga) ; a fourth is just being ingulfed. The nucleus is not seen. 



B, Difltugia urceolata, with shell built of sand-grains and pseudopodia far ex- 

 tended. 



C, Arcclla mitrata, a transparent individual showing the protoplasmic body sus- 

 pended within the shell ; several vacuoles are shown, but no nucleus. 



(Highly magnified.) 



