Amphitrema wrightianum Archer, 1869
Diagnose: Test ovoid, symmetrical, more or less compressed; composed of a transparent membrane, with adherent foreign bodies; two apertures at opposite poles; nucleus central; one to several contractile vacuoles; straight filopodia, sparsely branched, radiating; apertures provided with short tube like external collars. Zoochlorellae present.
Dimensions: Length 61-95 µm.
Ecology: In wet or submerged Sphagnum vegetation. I found ample specimens in a quaking bog along the Bert Bospad, The Netherlands.
Remarks: This genus is together with genus Archerella closely related to the Labyrinthulidae. It has been transferred to Stramenopiles by Gomaa et al. (2013).