Pyxidicula invisitata, 33 µm in diameter

 

Pyxidicula invisitata Awerinzew, 1906

 

Diagnosis: shell patelliform, colorless to brown, with distinct punctuation; aperture round, bordered by a narrow hollow rim with areolated structure; contractile vacuole single; pseudopodia unknown; vesicular nucleus with central nucleolus.

 

Dimensions: Awerinzew (1906): 40-50 µm; Cash: diameter 25-50 µm; my measurements 33-67 µm.

 

Ecology: Sphagnum. I found this species in Tirol, Austria.

 

Remarks: All photomicrographs are taken from material kindly supplied to me by Angie Opitz in Tirol, Austria.

 

Pyxidicula invisitata
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
Pyxidicula invisitata
Pyxidicula invisitata
Hollow rim, detail below
Pyxidicula invisitata
Pyxidicula invisitata
Inside the hollow rim, some structures are visible. These structures are the walls of the areoles or compartments.
Pyxidicula invisitata
Pyxidicula invisitata
Pyxidicula invisitata
Pyxidicula invisitata
Pyxidicula invisitata, 36 µm
Pyxidicula invisitata
Pyxidicula invisitata
Pyxidicula invisitata