A Deflexum Guide
Credit: Marina Potapova
  1. Striae parallel throughout both valves
  2. Areolae within a stria usually visible
  3. Short marginal striae present in the central part of raphe valve

The raphe valve is concave and the rapheless valve convex. Valves are linear-elliptical or elliptical with subrostrate ends. The striae are parallel throughout both valves. The striae are uniseriate and areolae are usually discernible. There are often very short striae present at the margin of both valves. The axial area is narrow and only slightly widened in the valve center.