Skip to content

Diagnostic features

Valves are identical, each possessing a raphe (i.e. the genus is biraphid).  "Napoleon's hat" shape in valve view, which is also seen paired in girdle view since the girdle is narrower at the short edge. Raphe positioned along the short edge of the valve, and curving into a V shape pointing towards the long edge in the centre (the extent of this varies by species). Transverse lines of thickened silica give the cell a heavily ribbed appearance.

Typical habitats

Lakes and rivers with moderate to good water quality.


Kingdom Chromista
Phylum Ochrophyta
Class Bacillariophyceae
Order Rhopalodiales
Family Rhopalodiaceae
Common name Diatoms