Abstract
A species of freshwater oligochaete, Propappus volki Michaelsen, 1916, is newly recorded from sand and gravel bottoms of several unpolluted streams in Honshu, Japan. The present material agrees well with the previous descriptions of this species except that the spermathecal ampulla is shorter and the proboscis is more elomgate than those described earlier. This is the first record of the family Propappidae Coates, 1986 (New Japanese name: Ko-himemimizu-ka) and the genus Propappus Michaelsen, 1905 (New Japanese name: Ko-himemimizu-zoku) in Japan. It provides evidence that the oligochaete fauna in Japan is more closely related to the Holarctic than to the Sino-Indian zoogeographical region. Propappus volki can be regarded as a good bio-indicator for unpolluted water.
