Marsh — Limnetic Crustacea of Green Lake. 



211 



Daphnia may be found at all depths, but is most numerous in 

 the upper ten meters. In some cases, however, more than fifty 

 per cent, of the catch is below the twenty meter line. 



Very few Daphnias occur in winter, and I could not distinguish 

 any effect of season on distribution. 



The averages of the day and night hauls of '94 were as fol- 

 lows: 



Day, Oct. '94.. 

 Night, Oct. '94, 



0-5 



38.39 



54.48 



5-10 



24.43 

 23.01 



10-15 



15.40 

 13.46 



These averages would seem to indicate a movement towards 

 the surface at night. I am not sure that this inference is war- 

 ranted, however, for the averages are of numbers with wide 

 limits of variation, and I accept the conclusion with consider- 

 able doubt. 



BOSMINA. 



No. 



Total 

 No. 





Per 



cent. 





of Coll. 



0-5 



5-10 



10-15 



15-20 



20-25 



25-30 



30-35 



35-40 



40- 



1.94.. 



9 



57 



112 



98 



26 



95 



57 



106 



280 



64 



40 



85 



51 



7 



212 



64 



37 



72 



151 



115 



257 



89. 



56.14 



71.43 



65.31 



11.54 



42.12 



42.10 



75.47 



31.43 



37.50 



20. 



47.06 



78.43 



77.92 



75.47 



56.25 



13.51 



38.88 



70.20 



70. 



80.93 



11. 



14.04 



17.86 



16.33 



61.54 



29.47 



28.08 



7.55 

 10. 



6.25 

 50. 

 28.24 



3.92 



6.49 

 11.32 



6.25 

 43.24 

 50. 

 13.25 

 15. 

 12.45 

















4.94.. 



21.05 



7.14 



4.08 



7.69 



22.35 



3.51 



.94 



34.29 



18.75 



20. 



9.41 



5.88 



6.49 



13.11 



28.12 



43.24 



5.55 



10.59 



6.10 



1.55 



7.02 

 3.57 



12.24 

 3.85 

 4.21 



21.06 



5.71 

 9.37 



10. 



14.12 

 3.92 

 5.19 



1.75 











5.94.. 











6.94.. 





1.02 



1.02 







7.94.. 





15.38 



8.94.. 



1.5.09 



10. 



25. 



1.05 

 5.27 









10.94.. 









H.94.. 









12.94.. 



8.57 









13.94.. 







3.13 



14 94.. 











15.94.. 







1.17 







16.94.. 



1.29 



5.88 





1.96 



17.94.. 







2.59 



18.94.. 











20.94.. 



6.25 



3.i3 











21.94.. 











22.94.. 



2.78 

 3.31 

 5.20 

 1.95 



1.39 

 2.65 

 1.70 

 1.56 



1.39 









24.94.. 









25.94.. 



1.70 

 .39 



1. 







26.94.. 



.39 



.78 



