Small Free-Living Heterotrophic Flagellates from Marine Intertidal Sediments of the Sydney Region, Australia Author Lee, Won Je text Acta Protozoologica 2019 58 4 167 189 http://dx.doi.org/10.4467/16890027ap.19.016.12018 journal article 10.4467/16890027AP.19.016.12018 1689-0027 12637266 Trepomonas agilis Dujardin, 1841 Figs 1d , 2d Description : Cell is ovoid, but S-shaped in cross section and is about 10 µm long. Two nuclei are located anteriorly. Two groups of flagella are inserted laterally at the end of each groove: two long flagella and six short flagella. The length of the long flagella was not measured, but the short flagella are less than half the cell length and lie in the grooves. The cell moves by swimming. Contractile vacuoles are seen. One cell was observed at Kogarah Bay. Remarks : This species has been found at a marine site in Australia ( Bernard et al. 2000 ), and also has been reported widely from freshwater, wastewater and anoxic (e.g. Playfair 1921 , Lavier 1936 , Calaway and Lackey 1962 , Brugerolle 1973 , Eyden and Vickermann 1975, Zhukov and Mylnikov 1983 , Fenchel et al. 1995 ). Previously reported cell length ranges are from 8 to 22 µm. This genus was reviewed by Mylnikov (1985) to include 7 nominal species: Trepomonas agilis Dujardin, 1841 , T. angulatus Klebs, 1893 , T. communis Klebs, 1893 , T. latecapitata Skuja, 1956 , T. rotans Klebs, 1893 , T. simplex Klebs, 1893 , T. steini ( Stein, 1878 ) Klebs, 1893 . Trepomonas agilis is hard to distinguish T. angulatus , T. communis and T. simplex , which have similar features such as cell appearance and having two long flagella and six short flagella ( T. agilis , 8-22 µm; T. angulatus , 30 µm; T. communis , 13–25 µm; T. simplex , 7–8 µm). Trepomonas communi s was regarded as a junior synonym of T. agilis ( Bernard et al. 2000 ) . Here, other two species ( T. angulatus and T. simplex ) are regarded as junior synonyms of T. agilis .