598 



FRESH-WATER BIOLOGY 



Fig. 905. Polychaetus collinsii 

 Gosse. X 250. (After 

 Jennings.) 



B 



Fig 906. Hydatina senla Ehr. A, Dorsal view of female. 

 X 150. (After Weber.) B, Corona. (After Wesenberg- 

 Lund.) CTrophi. (After Weber.) 



Fig. 907. Cyrtonia tuba 

 Ehrenberg. X 200. 

 (After Rousselet.) 



Fig. 908. Triphylus lacustris Ehrenberg. X 134. (After Western.) 



