Difflugia fallax Penard, 1890
Diagnosis: Shell hyaline or yellowish-greenish, black at low magnification, round in cross section, formed of a clear chitinous envelope in which are embedded amorphous, flat, siliceous scales. Aboral end rounded, sometimes slightly pointed. Anterior part gradually attenuated to end in a round and wide terminal mouth. Normal, clear plasma, filling only part of the shell, clearly visible by transparency through the flat scales; epipods often very long; round nucleus and contractile vesicle (often two) at the rear. Large pseudopodia, with very brisk movements, often numerous, sometimes on the contrary a single one in a rapid step, frequently lying down and spread out on the shell, which then seems covered with a mucilage (description after Penard, 1890).
Dimensions: Penard: height 40-60 μm; diameter 20-35 μm.
Ecology: Fresh water, Wiesbaden, Odenwald, Germany.