Small Free-Living Heterotrophic Flagellates from Marine Sediments of Gippsland Basin, South-Eastern Australia Author Lee, Won Je text Acta Protozoologica 2015 54 1 53 76 https://www.mendeley.com/catalogue/2d9e5f2c-507d-342d-bf76-2776eae6f93a/ journal article 298879 10.4467/16890027AP.15.005.2192 a177a1e6-d8dc-4f38-b223-a242595ec33c 1689-0027 10994295 Metromonas grandis Larsen and Patterson 1990 ( Fig. 4i ) Observation: Cells are leaf shaped, 5 to 11 µm long and dorso-ventrally flattened. One side of the cell appears folded. The cells have two flagella of unequal length. The long flagellum is 1.5 to 2.5 times the cell length and trails behind the cell when gliding. The shorter flagellum is inactive, less than 2 µm long, and inserts to the right of the major flagellum and is always present. The nucleus lies near the flagellar insertion. The cells attach to the substratum with the longer flagellum and move with a nodding action – like a pendulum. Relatively common. Remarks: This species was reported from marine sites in Australia , Brazil , Fiji , Hawaii and Turkey (Aegean Sea), and cell length reported was 5 to 12 µm ( Larsen and Patterson 1990 ; Tong et al. 1998 ; Lee and Patterson 2000 ; Al-Qassab et al. 2002 ; Lee 2002b , 2006b ; Aydin and Lee 2012 ). Generally, the current observations are in agreement with those of Larsen and Patterson (1990) and Lee and Patterson (2000 ; p. 552, Fig. 26f). Metromonas grandis is distinguished from M. simplex by its cell shape, slightly larger size and folded margin. The cell shape and folded margin may be good diagnostic characters for this species. This species usually co-occurs with M. simplex . According to Lee (2002b) , Skvortzov (1957) reported 9 new Ancyromonas species with one long flagellum, but these species may be gliding stages of Metromonas . The short flagellum in Metromonas is easy to overlook.