152 Illinois State Lahoratory of Natural History. 



A is located. Not far below this issues the moat ex- 

 tensive How of water from the muddy and sandy shore 

 on the east side of the lake, maintaining there a consid- 

 erable variety of plants and animals left upon it in spring 

 by the receding waters. This is Station B. The lake 

 itself is moderately shallow, and is filled during low water 

 in summer by a dense mat of Ceratophyllum, Anacharis, 

 (Edogonium and other algae, with areas of Nelumbo, 

 Nymphiea, Vallisneria, and Potamogeton. Through this 

 mass of vegetation the clear water of the lake slowly 

 moves towards the river, reinforced by the constant in- 

 flow. 



Station C is located near the outlet of the lake, the 

 shores here being near together and sheltered. The east 

 bank is sandy, with a muddy coating over the part 

 which is exposed at low water, while the west shore 

 is of black mud grown over with willow trees and over- 

 flowed in moderately high water. The water on both 

 sides is thickly filled in summer with algae and other 

 aquatic plants. Here during the first season our cabin- 

 boat was located, giving us a greater opportunity to 

 make observations at this station than at some of the 

 others, to which fact is due a slight preponderance of 

 data from this place. 



At the opening of the second season (1895) another 

 point, Station L, was selected in Dogfish Lake, a branch 

 of Quiver Lake on the west, also matted with vegetation 

 but without flow of spring water. 



Near Station C, in the river itself, is Station E, a 

 gently sloping muddy shore with but little vegetation; 

 and in a weedier but more exposed position at the side 

 of the broad expansion of the river known as Havana 

 Lake, is Station D. 



In the narrower and more rapid part of the river 

 below the city is Station H, with steeper shores, sandy 

 and gravelly on the east and muddy on the west. 



Between Havana Lake and the mai-gin of the sand 

 plain at the east is a low bare island, separated from 



