The cells are cylindrical, ranging from 6 to 30 µm in diameter, and they exhibit a consistent curvature along the pervalvar axis. They are linked together in curved chains, often forming spiral arrangements. The valves are flat and have rounded edges. A prominent spine is present along the valve margin, which fits into a depression on the adjacent cell. There are numerous collar-like intercalary bands. The presence of imbrication lines may not always be apparent, but they are sometimes very clear. The cell wall is weakly siliceous and lacks discernible structure. The cells contain numerous small, oval chromatophores, with the nucleus positioned near the cell wall.