Pseudodifflugia archeri Penard, 1899
Diagnosis: shell chitinoid, grey brownish, broad elliptical, usually not compressed, covered with small mineral particles; aperture circular; plasmabody hardly visible through the thick covering of the shell, not completely filling the shell; cytoplasm and nucleus normal; filopodia numerous, long and straight, branching, but not anastomosing.
Dimensions: literature 50-170 µm, seldom longer. My measurements: 52-60 µm.
Ecology: Sphagnum, waterplants and detritus of lakes and ditches.
Remarks: At first glance this species can easily be confused with Diaphoropodon mobile. The main difference is the lack of the so called radiating rods in Diaphoropodon.