These thread-like cells are elongated and roughly four-sided. They are typically solitary. The valves are extremely narrow and linear, measuring 1 to 4 millimeters in length and 3 to 6 micrometers in width. Delicate spines are present at the corners of the valves, with a density of about three spines per 10 micrometers in the central part of the cell, decreasing towards the ends and sometimes absent. Marginal spines can also be entirely lacking at times. Short marginal ribs, approximately 14 to 16 per 10 micrometers, mark the cell membrane. Additionally, there is a mucilage pore located near the cell’s ends.