(seek-it-tell-us) parvulus(Griessmann, 1913) Patterson et al., 1993. Cells are 2 to 4.5 microns long and somewhat triangular or rounded. There is a mouth protruding on the right ventral side of the cell. The cells have two flagella, the acronematic anterior flagellum beats slowly and stiffly with a small excursion, and inserts apically. It is slightly longer than the cell length. The non-acronematic posterior flagellum is about 2.3 to 3 times cell length, emerges from the ventral face of the cell and trails under the body. The cells move slowly by gliding with the anterior flagellum in close contact with the substrate.