Hedriocystis pellucida Hertwig & Lesser, 1874
Diagnosis: Cell surrounded by a stalked, non-siliceous polygonal shell; shell hyaline, colorless, with small holes, pores, through which non-branching axopodia radiate; axopodia with some granules, usually 6-15; vesicular central nucleus; flagellated zoospores.
Dimensions: Shell Ø 16.8-30 µm; stalk 36-90 µm.
Ecology: Fresh water, in different types of water; on waterplants and sediment. Europe.