Stephanodiscus Minutulus Guide
Credit: Mark Edlund
  1. Valves small
  2. Valves concentrically undulate
  3. Spines present at each interfascicle
  4. Interfasicles narrow

Valves are small and concentrically undulate. A short spine is present on the interfascicle at the valve face-mantle junction. Interfasicles are uniform, narrow and may be straight or wavy.