Assulina muscorum, 54 µm, stacked image

Genus Assulina Greef, 1888

Diagnosis: Shell usually brown, ovoid, compressed, biconvex in cross-section, with overlapping elliptical scales; aperture narrow oval, more or less crenulate with organic margin; nucleus vesicular, filopodia.

Remarks: Five species have been described so far, but they are hard to distinguish from each other light microscopically. It’s questionable if they represent separate species. The original descriptions are inadequate.

Known species:

Assulina – after Lüftenegger et al, 1988
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