Clypeolina “oblong” (work title)

Diagnosis: Shell elongate elliptical, compressed, lenticular in cross-section, consisting of a double envelope. The outer envelope is composed of two opposed chitinoid valves covered with fine mineral particles, with a flexible aperture.

Dimensions: Length 146-156 µm (n=3).

Ecology: Fresh water. Found in sediment and floating debris of a mesotrophic ditch. Observed food: large diatoms.

Geographical distribution: Nature reserve Naardermeer, Netherlands (Siemensma, pers. obs.).

Remarks:  This Clypeolina may be conspecific with C. marginata but differs in its more oblong shape compared to the typically elliptical form. I observed it twice in the same area where C. marginata was also found.