The diatom cell walls are flat or nearly flat, with a mantle that can slope or remain straight. These cells contain multiple small, rounded chloroplasts. In the girdle view (side view), the cells appear discoid with thick walls. In the valve view (top view), there is no central rosette; instead, there are coarse areolae, small openings arranged in irregular radial rows. Essentially, the frustules, or siliceous cell walls of this diatom, have a coin-like shape.