This part consists of three sections. The first deals with quantitative studies of the fauna of sandy bottoms sampled at two points on the river; a Birge-Ekman grab was used and samples were sifted through No. 3 grit gauze. The second section deals with the bottom fauna of three tributaries and discusses possible reasons for differences between these faunas and that of the main river. The third section comprises biological notes on most of the species encountered during the survey; these are arranged systematically.