Clypeolina sp.

Diagnosis: Test strongly compressed, thickness about 1/4 of the length, broadly ovoid, covered with small mineral particles. In lateral view, the test is lenticular shaped. Aperture irregularly shaped, flexible, capable of deformation. Filopodia long, slender, and often branching. Zoochlorellae present, likely in endosymbiotic association. Nucleus ovoid.

Dimensions: Length 75—110 µm; width 83—98 µm; thickness about 25 µm (n=7).

Habitat: In floating debris of an eutrophic ditch, March.

Geographical distribution: Nature reserve Naardermeer, Netherlands.

Remarks: Clypeolina sp. differs from C. marginata in shape.