The cells are elongated and cylindrical, with valves that are typically conical and curve at the apex. In smaller individuals, the intercalary bands are arranged in two dorsiventral rows and have a scale-like, rhombic appearance. However, in larger forms, there can be up to eight or more rows of these bands. Detecting imbrication lines, which are overlapping features, can be a challenging task. These cells have robust processes that gradually decrease in size from the base to the tip and exhibit a claw-like curvature, lacking any wing-like structures. The cell wall is thin and weakly siliceous, with very delicate punctation. Within the cells, numerous small chromatophores are present.