Genus: Body long to ovoid; apex fan-shaped; txicysts evenly distributed along edge of apex (Illustrated Guide, 1985).
Body elongate, circular in cross section; antrerior obliquely truncated, surmounted by an unciliated apical ridge,
which is lined with trichocysts; cytostome slit-like (Carey, 1992).
Very many species (Corliss, 1979).
Species: Cell body 120, 600 μm long (Kahl, 1930).