The cells are grouped together in star-shaped colonies or zigzag bands, appearing as linear in the girdle view. The valves are extremely slender and linear, with clear ends that are only slightly different from each other. One end is rounded and blunt, while the other end is usually slightly widened and then narrows to create a wedge-shaped point. The valves measure between 90 and 210 micrometers in length and are 2-4 micrometers wide. Small and evenly spaced spines can be found along the margins, with 6-9 spines per 10 micrometers. Apart from the spines, the valves lack any distinctive features.