Melosira Normannii Guide
Credit: David Burge and Mark Edlund
  1. Cells large, with thick walls
  2. Rimoportulae present
  3. Central spiral pattern on valve face

Cells are large and heavily silicified. A small central area opens to spiral anastamosing rows of areolae. The mantle has pervalvar rows of areolae and a ring of rimoportulae. The internal margin of the mantle is polygonal.