Pyxidicula invisitata, 33 µm in diameter (Tirol, Austria)
Pyxidicula invisitata Awerintzew, 1907
Diagnosis: Shell patelliform; colourless to brown; surface with distinct punctation. Aperture circular, bordered by a narrow hollow rim with an areolated structure. Contractile vacuole single. Pseudopodia unknown. Nucleus vesicular with a central nucleolus.
Dimensions: Awerintzew (1907): 40–50 µm.
Cash: 25–50 µm.
Own measurements: 33–67 µm.
Ecology: Sphagnum.
Remarks: All photomicrographs were taken from material kindly supplied by Angie Opitz (Tirol, Austria).
Drawing in: Cash, Wailes & Hopkinson (1919) The British Freshwater Rhizopoda and Heliozoa.
Pyxidicula invisitata, cross section in side view, 33 µm
Pyxidicula invisitata, 37 µm in diameter
Pyxidicula invisitata, 33 µm in diameter with clear hollow rim
Hollow rim, detail below
Inside the hollow rim, some structures are visible. These structures are the walls of the areoles or compartments.
Pyxidicula invisitata
Pyxidicula invisitata, 36 µm
Pyxidicula invisitata