Genus Argynnia Vucetich, 1974
Diagnosis: Shell compressed, aperture surrounded by siliceous plates, giving it a rough outline. Shell greyish, composed of various euglyphid plates, mixed with diatom fragments and mineral particles, porous cement. The structure of the test is intermediate between Nebela and Difflugia. Nucleus: ovular.
Type species: Argynnia schwabei.
Remarks: This genus was proposed by Jung (1942b) without type designation and validated by Vucetich (1974) including only three species from the southern hemisphere.
Its taxonomic position within Hyalosphenidae or even Difflugina is questionable.