Some Polyclad Flatworms from the Hawaiian Islands

ONE MAY SUPPOSE that a rich polyclad fauna exists along the shores of the Hawaiian Islands, but our knowledge of Hawaiian polyclads is, in fact., very limited. As far as I can ascertain, only the follo.wing species are recorded from the Hawaiian Islands in the literature: Planocera hawaiiensis Heath, 1907; Taenioplana teredini Hyman, 1944; and 5tylochoplana inquilina Hyman, 1950. The first merits further examination, but the specimens cannot be located. Three further species from Hawaii have been received for identification, from the United States National Museum, and furnish the material for the present article, which thus adds something to our small knowledge of the polyclad fauna of these islands. All three species belong to the Acotylea and to the section Schematommata. As the taxonomic categories that concern these three species have been carefully defined in a recent publication (Hyman, 1953a), there appears no need for repetition of these definitions here.