These diatoms, lacking raphes, possess elongated, slender frustules visible in both valve and girdle views, forming ribbon-like colonies through concealed, interlocking spines at the valve edges. Typically, they attach to submerged plant surfaces. In the girdle view, cells appear oblong with a central swelling, linking to create a ribbon colony. Symmetrical valves feature transverse striae, with a linear, elliptical shape and rounded edges. Often, a gap exists between cells on each side of the central swelling. Each cell contains two distinct chloroplasts, contributing to their photosynthetic capabilities.