6o2 



FRESH-WATER BIOLOGY 



Fig. 914. Eretmia triihrix Gosse. 

 (After Gosse.) 



Fig. 916. Nothol- 

 ca longispina 

 Kellicott. X 

 170. (After 

 Weber.) 



Fig. 915. Gastropus kyptopus Ehr. 

 X 170. (After Hudson and Gosse.) 



Fig. 917. Gastropus stylifer 

 Imhof. X 200 (After 

 Weber.) 



Fig. 918. Ploesomaleniictdare 

 Herrick. X 300. (After 

 Wierzejski and Zacharias.) 



Fig. 919. Ploesoma hudsoni Imhof. X 150. (After 

 Wierzejski and Zacharias.) 



F1G.930. Ploesoma truncatumLe^ 

 vander. X x6o. (After Weber.) 



