An interesting group of testate amoebae is the genus Difflugia. There have been described hundreds of species, but the question is: how many of them are true species? Most descriptions are inaccurate of just based on one single test. Probably this group consists of several genera. Only DNA sequencing can help here. One of my projects is to make a visual map of all known species. It’s one of the most difficult taxa to identify.
Yogsothoth carteri, after Shishkin and Zlatogursky, 2018 Yogsothoth carteri Shishkin and Zlatogursky, 2018 Diagnosis: Individual cells in a colony have a diameter of 9.7-15.2 µm;
Yogsothoth knorrus, after Shishkin and Zlatogursky, 2018 Yogsothoth knorrus Shishkin and Zlatogursky, 2018 Diagnosis: Individual cells in colony have a diameter of 5.53-13.26 µm; they
Yogsothoth carteri, from Shishkin and Zlatogursky, 2018 Yogsothothidae Shishkin and Zlatogursky, 2018 Diagnosis: Centrohelids covered with two types of tangentially-oriented plate-scales, having a different morphology.
A. dürrschmidtidae – after Wujek, 2003 Acanthocystis dürrschmidtidae Wujek, 2003 Diagnosis: Cells 35-40 µm (based on a whole mount). Periplast comprising scales of two types, plate
Centroplasthelida Febvre-Chevalier and Febvre, 1984 Diagnosis: Phagotrophic and non-photosynthetic protists with one large spherical or near spherical centrosome at the center of the cell
Pterocystida Cavalier-Smith and Heyden, 2007 stat. n. Phylogenetic diagnosis: The least inclusive clade, containing Pterocystis devonica, Raphidiophrys heterophryoidea and Choanocystis curvata, but not Acanthocystis