Centric
Coscinodiscus
- Valves circular
- Areolae radiate from central annulus
- Areolae loculate
- Rimoportulae present
The frustules of extant Coscinodiscus
species are discoid, barrel-shaped, or slightly eccentric in girdle view. Cells occur singly except immediately following division and can be quite large (up to 500 µm in diameter). The valve face is flat or lens-shaped, with radiate areolae that extend from a central annulus. The areolae are...