Acrochaetium scinaiae Dawson (Acrochaetiaceae, Rhodophyia) is reported as a new entry not only to the present writer's algal list of the Oki Islands in the Sea of Japan but also to the marine algal flora of Japan.
Results of the present writer's detailed observations on the morphology of this taxon have led him to retain the species name of Acrochaetium scinaiae.