The following illustrations a~e reprinted by permission from Fresh 

 Water Biology by Ward and Whipple, published by John Wiley and Sons, 

 Inc.: 



p. fig. fig. 



127 100 959. .. .Philodina, (after Weber) 



872. . . .Diglena, (after Dixon-Nuttall) 

 893. . . .Euchanlis, (after Weber) 



129 102 948. . . . Melicerta, (after Hudson and 



Gosse) 



143 no 836. . . .Paragordius varius, (after Stiles, 



and I, 2, orig.) 



838. . . .Gordius villotti, (after Mont- 

 gomery) 



176 135 1322. . . . Limnochares, (modified from Pier- 



sig) 



177 136 1323. . . .Eylais (modified from Piersig) 



178 137 1324. .. .Hydrachna (modified from Piersig) 



