March, 1921] Macro-Fauna of Mirror Lake 141 



PART II. 



MIRROR lake: description and history. 



This part of the original thesis form is omitted here, as the 

 account in Miss Stehle's paper ('20), suffices. Points that should 

 be emphasized, however, are: the artificial origin (1872) of 

 the pond, the extensive alterations in 1895, really a second 

 starting point for the fauna and flora, the subsequent develop- 

 ment of these, and further changes made during and subsequent 

 to this survey. 



On April 16, 1919, after only two collections had been made, 

 a change was wrought in the smaller of the two ponds which 

 constitute Mirror Lake. The narrow neck of land between the 

 two ponds was cut through which lowered the water level in 

 the small pond about ten inches, and left organisms stranded 

 high and dry on the muddy shore. This was to be part of an 

 extensive "cleaning" out and general change in the pond 

 which fortunately did not come to pass while this work was 

 being done.* 



PART III. 



description of stations. 



Stations are not discussed in the numerical order in which 

 they were established, but in a natural arrangement which 

 brings together those nearest in position and environmental 

 conditions. The same order is used in the table. 



Station 1. This was a shallow station located off the 

 northeast shore of the small pond. It was a uniform area, a 

 few square yards in extent, not with a soft, muddy, oozy bottom 

 as most of the pond had, but with a partly gravelly, partly 

 muddy bottom, sloping gradually down from the shore-line 

 and only several inches deep on the average. 



The lowering of the water level (April 16) exposed a very 

 large part of the station, and left snails, leeches, etc., stranded 

 on the new muddy shore. 



* In the summer of 1920, after this study was terminated, the entire plan of 

 altering Mirror Lake was carried out. It was drained, and then refilled after 

 the small pond was completely obliterated, and the same done with the attractive 

 island, the largest curves in the shoreline, and the northwest arm and rustic 

 bridge of the large pond. The entire shoreline (it should be added) was lined with 

 a wall of cobblestones! 



