С. vulgaris (Francé, 1913) Volz, 1928

Fig. 7 i

Difflugiella vulgaris Francé, 1913

Original description. Francé, 1913, P. 352, Fig.1.

Description. Shell globose or somewhat oval, rather thick-walled, transparent, structureless. One end with very small circular aperture surrounded by thickened wall. Sometimes there occur yellowish and brownish to darkbrown specimens.

Measurements. Shell length 15–18 µm, shell width 10–21 µm, aperture diameter 3.8–4.5 µm.

Habitat. Soils, common in forest litter, sometimes in rhizosphere, once recorded in Sphagnum.

Geographical distribution. Germany, Bulgaria. Russia.

Several taxa with generic names Cryptodifflugia and Difflugiella were not described above by following reasons:

1. The descriptions of Difflugiella heynigi Schönborn, 1965 and Cryptodifflugia lamingerae Chardez, 1977 do not correspond to the diagnosis of the genus Cryptodifflugia. Both taxa are considerably larger and are characterized by apiculate aboral end of the shell as well as by prominent long neck with collar. Most likely both species might be included in the genus Chardezia.

2. The names Cryptodifflugia sakotschawi and Cryptodifflugia kelensis were mentioned by Tarnogradsky (1945, 1945a), however, their descriptions and figures have never been published.

3. Cryptodifflugia turfacea Zacharias, 1903 and C. vanhoornei Beyens et Chardez, 1987 are characterized by retort-shaped shell. We consider this character as important to make a taxonomic decision on transferring these species to another genus.