Abstract
Thirteen samples were collected at four stations in the Uji River, Kyoto, during the period from May 1970 to November 1973. The species identified belong to 33 genera and 165 species in total as benthic diatoms. The values of R. F. of those diatoms which are more than 5% of total 20. Those twenty diatoms can be classified according to the three grades of water quality as follows.
Oligosaprobic only : Cymbella tumida, Fragilaria crotonensis, Melosira granulata, M. granulata var. angustissima, M. italica, M. solida and Nitzschia clausi. Both α-oligo and β-mesosaprobic : Cymbella turgidulla, Navvicula cincta, N. cryptocephala and N. cryptocephala var. exilis. Both α-oligo, β- and α-mesosaprobic : Cymbella ventricosa, Gomphonema olivaceum, Nitzschia aciularis and Synedra ulna. β-mesosaprobic : Nitzschia amphibia, N. frustulum and Synedra radians. Both β- and α-mesosaprobic : Synedra rumpens var. familiaris. α-mesosaprobic : Synedra acus.
