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).
Spathidium procerum Kahl, 1930: Cell body vermifrom, 260-400 μm long, with an expanded, fan-shaped anterior; a large apical ridge with many trichocysts follows the curve of the obliquely truncate apical region; macronucleus long moniliform (Carey, 1992).