Actinocylclus Normanii Guide
Credit: Mark Edlund
  1. Areolae radiate in pseudosectors
  2. Areolae similar in size across valve
  3. Rimoportulae marginal

Valves concentrically undulate, with radiate areolae. Areolae are 8-12 in 10 ┬Ám and maintain constant size throughout the valve. Rimoportulae (4-8) are located equally spaced along valve margins. The pseudonodule is not visible due to its position on the valve / mantle interface.