(carp-ee-dee-a-moan-ass) bialata (Ruinen, 1938) Lee and Patterson, 2000. Cell outline is kidney-shaped. Cells are 6 to 14 microns long (mostly 9 to 12 microns), not rigid, and with a longitudinal ventral groove. A membrane moves down along the groove every 4 - 6 seconds. Two flagella emerge from the anterior part of the cell, the anterior flagellum bends backwards, is about the length of the cell and beats over the cell with a slow sweeping motion. The acronematic posterior flagellum beats asymmetrically and is about 1.5 times cell length. The posterior flagellum may vibrate actively in the groove when not beating. The cells consume bacteria up to 5 microns, and food materials are transferred by the moving membrane to the back of the cell. The cells may have many food vacuoles and attach to the substrate with the tip of the posterior flagellum. The cells move slowly by skidding or gliding with the anterior flagellum beating with a flicking motion. Commonly observed in late cultures.