15 
half of 1896 monthly collections were made, and since that 
date the interval has been reduced to a fortnight. 
During the past year a drainage district has been organized 
in the territory including and adjacent to Phelps Lake. The 
object of this organization is the reclamation of the fertile 
bottom south of Spoon River. A large dike is being built along 
the north limit of the district, reaching the river a short distance 
above the north end of Phelps Lake. From this point it passes 
southward along the river bank for several miles to a point 
some distance below the mouth of Phelps Lake Slough, and 
then turns westward to the west bluff. The drainage of the 
enclosed area will be accomplished by several large ditches 
leading to the southeast, where pumping works are planned to 
insure the removal of the water when the surrounding country 
is flooded. Owing to the drainage of this lake our operations in 
this locality must cease with the present season, which leaves 
us In possession of quantitative collections extending through 
three years, in each of which the water entered in the winter or 
spring overflow, and was slowly removed by evaporation and 
seepage throughout the summer months, the catastrophe cul- 
minating in the late fall. We have thus in our possession a 
basis for a tolerably complete record of the seasonal ftluctua- 
tions and changes in the fauna and flora incident to the drying 
up of this ephemeral body of water. 
Since September, 1896, collections have been made in 
Spoon River at intervals of a month or less, and during this 
time a number of qualitative towings have been taken for us by 
Mr. W. R. Deverman, of Topeka, Ill., from the waters of Quiver 
Creek. We have thus a good series of collections from 
tributary streams of the river for a comparison with those of 
the river itself. 
A plankton station was established in September, 1895, in 
Flag Lake, a large marsh between Thompson’s Lake and the 
Illinois River. Collections have been made here from that time 
at intervals of a month or less and were continued in 1897 
until July. Owing to the abundance of vegetation in Flag Lake 
this station was extremely difficult of access during the summer 
months, and owing to the abundance of flocculent debris of 
vegetation it was at all times difficult to secure a satisfactory 
