(Roundia) (Roundia) is a biological genus in the family Thalassiosiraceae and order Thalassiosirales.
Bacterosira
Coscinosira
Microsiphona
Minidiscus
Planktoniella
Porosira
Roundia
Shionodiscus
Spicaticribra
Stephanocyclus
Takanoa
Thalassiocyclus
Thalassiosira
Tryblioptychus