NORTHWESTERN LAKES OF THE UNITED STATES. 
87 
In July the greater part of the net plankton was found in the thermocline and 
the hypolimnion. The maximum number of copepods per cubic meter of water was 
found at 12 m. and of nauplii at 20 m. 
stratum. The Protozoa and copepods were more abundant in the August than in 
the July catches. 
