Skuja (1939: 123, pl. 10, figs 16, 17)
Cells heterotrophic, usually elongate, slightly compressed, 25-60 µm long, 14-25 µm wide, biflagellate. Flagella unequal, heterodynamic, both emerging from an apical canal; the shorter thicker flagellum directed anteriorly; the longer flagellum looped at the point of emergence and then directed back along the cell body. Cell surface with a smooth pellicle; pellicular strips not conspicuous. Cells have a gliding motion with distinctive reversal behaviour.
Southern Ocean, south of Australia; Arctic Canada and the Baltic (Vørs, 1992).
"Anisonema sp." was recorded from pack-ice assemblages in the Weddell Sea by Garrison & Buck (1989b).