Difflugia viscidula Penard, 1902
Synonym: Difflugia lemani Blanc, 1892
Diagnosis: Shell ovoid to slightly elongated oblong, circular in cross section, with rounded fundus; without a constriction between body and neck; neck, if distinct, short and composed of much smaller particles than the rest of the shell; neck sometimes with concave sides, like a vase. Shell composed of a mixture of small and large pieces of quartz, rarely with diatom frustules. Aperture circular, with regular outline, surrounded by small particles. Cytoplasm does not fill the whole shell, usually with brown granules; sometimes with zoochlorellae. One large ovular nucleus with many small nucleoli. Pseudopodia few, short, thin, very slow moving, rarely visible.
Dimensions: Penard (1902): 180-260 µm. Todorov and Bankov (2019): 200-267 µm. My measurements 189-202 µm.
Ecology: Freshwater, Sphagnum; cosmopolitan.
Remarks: Penard described this species in 1902 as D. viscidula, but in 1905 he wrote that he had made a mistake by which he thought that D. lemani was a much smaller species. He noticed erroneously 31-80 µm, instead of 180-310 µm, as given by Blanc (1892).