Aulacoseira Tenella Guide
Credit: Marina Potapova
  1. Ratio of mantle height to valve diameter < 1
  2. Rows of mantle areolae straight, inclined to the right
  3. 2-3 areolae in each row of mantle areolae
  4. Valve face with small areolae
  5. Spines very short

Valves are 5-8.5 µm in diameter, with a mantle height of 1.8-2.6 µm. The ratio of the mantle height to valve diameter is less than 1. The valve face is flat. Rows of pervalvar areolae are straight, slightly inclined to the right, and 21-25 in 10 µm, with 2-3 areolae in each row. The height of the collum is approximately 1/2 of the mantle height. The valve face is covered by small areolae. The spines are very short and triangular. The ringleiste is very shallow.