I found a fairly number of this amoeboid in fresh water sediments of Crailoo, the Netherlands. All cells were more or less ovoid, yellow-reddish with a furrow, a slit-like aperture. From this furrow some branching filopodia emerged. These amoeboids retracted their filopodia in bright light and started to swim away with a rotational movement. There were one, probably two cilia, each about as long as the cell diameter. The cell membrane was rough and covered with yellow reddish wrats. Nucleus granular and located in the posterior region of the cell.
At first I thought it was a Rhogostoma species, but cilia are not known for this genus.