PI. IV. — Minute plants and animals of pond water. Photo- 

 graph of part of a model showing life in one-half inch of pond 

 water, magnified one hundred times. Model designed and di- 

 rected by Roy W. Aliner, in American Museum of Natural 

 History, i, stem and i a, traps of Utricularia (p. lOo); 2, stem 

 and leaves of Elodea (p. 79); 3, green algas, Spirogyra (p. 50), 

 and 4, ChcBtophora; ^ydesrmd, Closterium (p. 49); 6, protozoan, 

 Vorticella (p. 57); 7, 8, 9, 10, rotifers (p. 127); 11, entomos- 

 tracan (p. 161); 12, hydra (p. 112); 13, larva of midge caught 

 in trap (p. 291); 14, egg of water-mite; 15, dead leaf. Diatoms 

 and desmids project from the surface of Utricularia stem. 



Courtesy of Dr. R. W. Miner 



