Arcella rota Daday, 1905
Diagnosis: Test in dorsal view circular with numerous, 38-40, small spines, giving the impression of a gear. These spines are curved, pointing downwards. Test in side view flat, height about ¼ of the diameter.
Ecology: Freshwater, Paraguay.
Tests that are bag or thumb-shaped Tests that are bag, finger or thumb-shaped.This group has no taxonomic significance. D. polliciformis D. lemani D. pecac D.
Difflugia polliciformis, after Van Oye, 1952 Difflugia polliciformis Van Oye, 1958 Diagnosis: Test more or less thumb-shaped, without clear neck, chitinoid, mainly covered with very
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