Arcella discoides
A. discoides scutelliformis, Ø 89 µm

 

 

Arcella discoides var. scutelliformis  Playfair, 1918

 

Diagnosis: Test relatively higher than the type, with nicely rounded sides in cross-section. Contour regular, pseudostome circular, relatively large, sometimes with a ring of fine pores. Dorsal side rounded, without undulations. Pseudostomal invagination about half the heigth of the shell, without pseudsomal tube.

 

Dimensions: Playfair (1918): diameter 44-95 µm; height 15-25 µm; pseudostome diameter 14-34 µm. Deflandre (1928): 61-82 µm; height 18-26 µm; pseudostome 17-28 µm.

 

Ecology: Sphagnum, submerged mosses

 

Arcella discoides
Arcella discoides
A. discoides scutelliformis, Ø 83 and 89 µm