Aulacoseira Crassipunctata Guide
Credit: Marina Potapova
  1. Ratio of mantle height to valve diameter > 1
  2. Rows of areolae on mantle straight
  3. Mantle areolae round, widely separated
  4. Valve face strongly convex or concave
  5. Ringleiste bell-shaped in cross-section

Valves are 4-12 µm in diameter, with a mantle height of 9-18 µm. The ratio of the mantle height to valve diameter is greater than 1. The valve face is strongly concave or convex. Rows of areolae on the mantle are straight, 5.5-9 in 10 µm, with 5-10 round areolae in 10 µm. The collum is approximately 1/3-1/4 of the mantle height. The valve face is covered by areolae. The ringleiste is broad, shallow.