Ditrema mukrous De Saedeleer, 1934
Diagnosis: Shell hyaline, small, with one side fastened to the substrate, with an open base, resembling an iglo; outline circular, often irregular. Shell usually with two opposite apertures, each with a short neck. Young shells colorless, older shells yellow to brown. Pseudopodia granular, fine, extending along the substrate. Nucleus globular with a central nucleolus.
Dimensions: De Saedeleer 12-14 µm; my measurements: 21-28 µm, from aperture to aperture; 9-15 µm in diameter.