Cells are usually oval but highly variable in shape.
The valve faces are highly ornate.
In contrast to e.g. Navicula species, Surirella fastuosa has
a circumferential raphe, running around the cell on the keel
formed at the point where valve face and mantle meet.
The external raphe fissure opens into a raphe canal situated at
the angle of the raised keel formed between mantle and valve face.
The raphe canal opens to the inside of the cell
through the perforate fibulate plate.