133 



EXFLANATiON OF FIGURES. 



Fig. 1. Didpfoiinis. Scale, one vertical space equals 100 iudividuals 

 per hundred liters of surface water. 



August 5-6. 



August 27-28. 



Fig. 2. Ci/clops. Scale, one vertical space equals 50 individuals per 

 hundred liters of surface Avater. 



■ August 5-6. 



August 27-28. 



Fig. 3. Dui)lnua hyalina. Scale, one vertical space equals 50 iudivid- 

 uals per hundred liters of surface water. 



Adult. ) 



r August 5-6. 

 - Young. J 



Fig. 4. DapJniia hijaliua. Scale, one vertical space equals 50 individ- 

 uals per hundred liters of surface Avater. 

 Adult. I 



\ August 27-28. 

 1 oung. ) 



