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The Ohio Journal of Science [Vol. XIX, No. 8, 



TEN YEAR POND. 



Pond III. 



The ten-year pond is a rock-bound basin 140 feet long and 

 97 feet wide, in the bed of a quarry which is still being operated. 

 It lies within three hundred feet of Pond I. It is surrounded on 

 all sides by a desert of bare rock or finely crushed stone for dis- 

 tances of seventy-five feet to a hundred yards or more. By 

 reason of this wide belt of bare territory this pond is probably 

 more isolated than are the two just described. 





Stations 1 and 2 of Pond III. 



The water was between four and five feet deep, except for a 

 small area where it was ten feet deep. This is about eighteen 

 inches less than the depth sometimes attained. There was very 

 little vegetation; two small willow trees and some rushes 

 growing in a shallow stretch along one side. In the center of 

 the pond there were thirty-two lily pads. None of these was 

 seen before the summer of 1917. Except for such few traces of 

 larger vegetation the pond presented a bleak appearance. 

 Stones in the water were well coated with algag, even at a depth 

 of several feet. The bottom was covered with two to three 

 inches of black silt composed of dust from the quarry and an 

 admixture of decayed organic material from the pond itself. 



