Centropyxis cryptostoma  Bonnet, 1959

Diagnosis: Shell ovoid, extended by a very covering visor leaving only a fairly low pseudostome. In lateral view, the ventral membrane curves strongly inwards forming, with the dorsal membrane which is parallel to it, the beginning of a duct reminiscent of that of Plagiopyxs callida (cryptostomy). Shell covered with amorphous, siliceous particles. Shell very light in color. Cell and cyst not observed.

Dimensions: Length 45 µm, major axis 35 μm, small axis 27 to 30 μm.

Habitat: Soil.

Geographical distribution: Pyrénées-Orientales, Banyuls region, Cerbère.

Remarks: The shape of the pseudostome separates this species from Centropyxis vandeli, which does not have an invagination of the ventral wall.