Family Hartmannellidae Volkonsky, 1931
Uninucleate amoebae, monopodial with a cylindrical pseudopodium when active. Most floating forms without radiating pseudopodia. Nucleus with a prominent central nucleolus.
| 1 | Distinctive hyaline zone in locomotive form | Hartmannella Copromyxa |
| – | Hyaline zone in locomotive form reduced or absent | 2 |
| 2 | Uroid, if present, reduced | Cashia |
| – | Uroid, often bulbous and villous | 3 |
| 3 | Cytoplasm often with prominent crystals or inclusions | Saccamoeba |
| – | Cytoplasm without crystals | Glaeseria |