The Bottom Fauna of the Middle Illinois River, 1913-1925

Its Distribution, Abundance, Valuation, and Index Value in the Study of Stream Pollution

Abstract

The present paper adds the findings of two more years (1924 and 1925) to our previous accumulation on the small bottom fauna of the middle Illinois River, and brings into comparison with the data obtained under the comparatively clean-water conditions of 1913-1915 the results of five summers' collecting in the more or less seriously polluted bottom muds in the same territory between the years 1920 and 1925.