Arcella lichenophila  Decloitre, 1965

Diagnosis: Viewed from above, the shell is shaped like an elongated hexagon; the pseudostome is elliptic with the major axis perpendicular to the major axis of the shell. The oral face is reinforced by three or four dark creases or folds. In lateral view the shell has a low height and the largest diameter is in the middle of the height. The dorsal surface is slightly convex and the ventral face is not invaginated.

Dimensions: Diameter 115—120 µm; height 90 µm; pseudostome 13 × 20—25 µm.

Habitat: In lichens on granite.

Geographical distribution: Morocco.