Plagiopyxis labiata
Family Plagiopyxidae Bonnet et Thomas, 1960
Diagnosis: Lobose testate amoebae with bilaterally symmetrical organic test covered with fragments of mineral grains, diatoms and organic debris; aperture a more or less invaginated slit on the ventral side, eccentric, overhung by an anterior lip, in ventral view often difficult to observe (cryptostome).
| 1 | Anterior lip of pseudostome a distinct, overhanging hood | 6 |
| – | Aperture more or less slit-like, no overhanging hood | 2 |
| 2 | Anterior lip of pseudostome with pores | Bullinularia |
| – | No such pores | 3 |
| 3 | Anterior (dorsal) lip curves below convex ventral face | Geoplagiopyxis |
| – | Posterior (ventral) lip curves below anterior lip, or pseudostome is an open slit | 4 |
| 4 | Aperture covered by the anterior lip | 5 |
| – | Aperture is an open slit | Protoplagiopyxis |
| 5 | Posterior (ventral) lip with extension towards anterior lip and connected to the dorsal side of the test from inside | Paracentropyxis |
| – | No extension of the posterior lip | Plagiopyxis |
| 6 | Ventral area (sole) rounded | Hoogenraadia |
| – | Ventral area (sole) flattened | Planhoogenraadia |
after Meisterfeld, 2002