(col-poe-dell-a) unguis. Patterson and Simpson, 1996. Cells are 8 - 13 microns long, bean-shaped in profile and somewhat flattened. The cells may have longitudinal lines of granules. Two flagella insert at right angles on one flat side about one third of the way down the cell. The anterior flagellum is nearly the length of the cell, inserts at the end of a deep, triangular curving depression. It is directed laterally and posteriorly. The posterior flagellum inserts at the top of a shallow longitudinal groove, is nearly two times the length of the cell, and is directed posteriorly. Some cells have large vacuoles containing eukaryotic prey material. The cells typically swim rapidly, usually in contact with the substrate. The cells erratically flip from one side to the other when swimming. Not common.