Pellitida Smirnov et al. 2011
Diagnosis: Thick cell coat does not contain scales, is integrated with the cellmembrane, and envelops the entire cell or part of the cell, leaving dorsal surface free.
D. australis after Playfair, 1917 Difflugia australis (Playfair, 1917) Gauthier-Lièvre et Thomas, 1958 Syn.: Difflugia bacillariarum var. australis Playfair 1917 Diagnosis: Test broadly ovate, with
D. baradlana after Varga, 1963 Difflugia baradlana Varga, 1963 Diagnosis: Test ovoid with a very small neck which is about 1/4 of the test length.
D. angelica after Gauthier-Lièvre et Thomas, 1960 Difflugia angelica Gauthier-Lièvre et Thomas, 1960 Diagnosis: Test spherical, slightly mammillated. Pseudostome regularly lobed like a star with
D. algaephila after Decloitre, 1977 (l) and Chardez (1980) Difflugia algaephila Decloitre, 1977 Diagnosis: Test ovoid, neatly pointed, with oblique round pseudostome. Dimensions: Length 73-75
Spherical tests Tests that are more or less spherical, some with a collar, but all without spines or other outgrowths. The aperture or pseudostome is
Compressed tests Compressed tests are more or less oval or elliptical in cross-section. The aperture is round or oval or even lobed. This group has no