Lecythium spec. a lateral view; b pseudostome with broad pliable collar; c optical cross section
Lecythium spec.
Diagnosis: test in lateral view broad elliptical or ovoid; in dorsal view circular; membane hyaline, yellowish to brown, covered with minute xenosomes; vesicular nucleus in the dorsal region; filopodia straight, branching and anastomosing, usually numerous; pseudostome flexible; membrane around the aperture pliable and flexible.
Dimensions: my measurements 20-40 µm; nucleus c. 12 µm (hard to detect).
Habitat: I found this species in sediments of the Spiegelplas and an oligotrophic fen near Kootwijk in the Netherlands. It looks like a Lecythium species, but it could also be a Pseudodifflugia. It also resembles Pleurophrys amphitremoides Archer, 1870, which is about 60 µm. It could also belong to the genus Schwabia Jung (1942).
Two specimens, probably dividing.
Specimen with typical pseudopodial network.
Specimen with typical pseudopodial network.
Cell with nucleus and cell with aperture visible.
Surface structure of the test. Shell 25 µm, oligothrophic fen – Kootwijk, the Netherlands
Two cells after dividing, still connected by a long string.