Family Vannellidae Bovee, 1970

 

Diagnosis: Amoebae have locomotive forms markedly flattened, fan-shaped, or linguiform with a prominant anterior hyaline zone without subpseudopodia. No posterior uroid. Floating form of most with radiating pseudopodia, either blunt or tapered. Nucleus of most with prominant central nucleolus, rarely with parietal lobes. Cytoplasmic crystals rare.
Glycocalyx of the only two genera studied by TEM differentiated into either pentagonal glycostyles (Vannella) or hexagonal arrangements (Platyamoeba).

 

Remarks: Family diagnosis emended by Page (1987) on the basis of this ultrastructural information. The present grouping of genera is based on morphological similarities at the LM level since ultrastructural details are unavailable for most.

 

1

Hyaloplasm smooth

2
 -

Hyaloplasm with surface features

3
2

Hyaloplasm extends posteriorly as border

Discamoeba
 -

Hyaloplasm predominantly anterior

Vannella
3

Surface features faint

4
 -

Surface features obvious

5
4

Usually with faint longitudinal edge ridges

Platyamoeba
 -

Usually with faint lateral folds

Clydonella
5

Hyaloplasm with series of superimposed waves

Unda
 -

Hyaloplasm with conoidal bosses

Pessonella