Genus: Highly flattened; pellicle firm; body form constant (Kudo, 1966). Chloroplasts small, discoid, pyrenoids usually absent; most species flat and leaf-shaped; often with ridges or fins running helically or longitudinally (Illustrated Guide, 1985).
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P. ranula
body, 81 x 42 μm
tail, 60 μm
Uruguay, 1999
P. ranula
153-160 x μm
Iyari marsh 1
Omachi
Nagano, 2007
P. ranula
μm
Iyari marsh 3
Omachi
Nagano, 2008