126 Illinois State Lahoraronj of Natural History. 



erable extent, and again contracting to fifteen or twenty feet in 

 width. It was not continuous at this time, and probably dur- 

 ing most seasons dries up in great part before the close of 

 summer. 



HAEKSTESS SLOUGH. 



Harkness Slough is a channel which extends almost exact- 

 ly parallel with Ballard Slough, and lies a quarter of a mile 

 further south. It is very narrow, — not fifty feet across in 

 much of the lower part of its course ; has steep banks ; forms 

 some rather deep pools ; and is, like Ballard Slough, extremely 

 muddy. A dense growth of trees lines its banks. It was 

 continuous as far as followed towards the Mississippi River (al- 

 though greatly reduced at some points), and, judging from the 

 current, was doubtless yet connected with the river. Still 

 there can be no doubt that it commonly dries up largely in 

 summer. 



GOOSE LAKE. 



An eighth of a mile south of the outlet of Harkness Slough 

 into Bear Creek, is a wide opening on theeast into Goose Lake,— 

 an open sheet of water, from the shores of which much of the 

 forest has been removed. It becomes shallower and its bottom 

 more sandy towards its south end, from which a channel ex- 

 tends which formerly put it into communication with the bay, 

 three quarters of a mile below. 



LIBBT LAKE. 



This name was given me by one of the fishermen for a 

 long, narrow pool on the west side of Bear Creek about mid- 

 way between the outlet of Goose Lake and the Bear Creek 

 sluice-gate. It is not named on any niaji at hand. It was in 

 some respects very dilTereut from any other water in which col- 

 lections were made. The water was quite deep, and, for the 

 situation, unusually clear and cool, and gave promise of a 

 growth of aquatic and sub-aquatic vegetation at the edges later 

 in the season. It is scantily edged with willow and button 

 bush and a few other trees and shrubs. 



