140 THE AMERICAN MIDLAND NATURALIST 



In the process of building the nest the fish clear the desired 

 location by swimming around and around the spot in a very 

 methodical manner; swimming clockwise three or four times then 

 erecting the body and using the tail as a fan or broom to clear away 

 the vegetation and other foreign substances ; then they swim counter- 

 clockwise for three or four times and go through the same process 

 of sweeping. At regular intervals, usually after four complete 

 cycles, they dart out to survey the surroundings for enemies, etc. 



They are gregarious in their nest building habits. We found 

 anywhere from 6 to 14 in a colony in the Cove. 



Marsh Pond — Kelley's Island. 

 July 8, 1916. 



Large marsh pond located about 75 yards from Lake Erie. 

 Great abundance of vegetation consisting of algae and spirogyrae. 

 The bottom was covered with a deep mud. The following forms 

 were found: beetles, Vv^ater striders, snails, few Gammaridae and 

 tree toads. Back swimming beetles, Hydrophylidae, Dyiiscidae; 

 numerous crayfish, minnows, frogs amid the vegetation, leeches 

 and Rhyncophoridde. 



This marsh was formerly a celery bed but now kept moist anc" 

 marshy by springs and seepage from the lake. 



Rock Bottom Pond — ^Kelley's Island. 

 July 8, 1916. 

 The pond was originally a quarry and has been blasted out at 

 least 14 years ago. It measured 100 feet wide and 120 feet long. 

 Rock}' bottomed and rock bound. Turbidity 9 inches. One corner 

 was covered with grass and willow bushes. Abundant algae and 

 spirogyrae around the edge. 



On the surface were found water striders, Gyrinidac, back 

 swimmers, Notoneciidae, midgepupae, diptera larvae, fish, turtles, 

 toads, leeches and snails. Also found an Oligocheat {Lumbricidus) 

 close to the rocks in spirogyrae. 



In a surface towing taken from a point 10 feet from the shore 

 along the bottom the following forms were found : 



Cyclops 75. 



Cypris 26. 



Numerous Colpoda which resembled Paramecium only smaller. 



Lake Erie and Sandusky Bay Farms. 

 July 17, 1916. 

 Con;|;£.rison of plankton in Lake with that in Bay. 



