Genus Microcorycia Cockerell, 1911
Diagnosis: Test is flexible and comprises two parts, upper test part and lower test part. The upper test part is dome-shaped with most species, its wall is thicker and less flexible than the lower test part. On the other hand, the lower test part consists of a thin, transparent skin, which shows no structure in the light microscope, can be folded up and is open downwards for extruding pseudopodia. The skin only loosely covers the cell body and can be contracted like a sack. There is a zone of gradual transition from the upper test part to the lower test part. The species ("morphospecies") of the genus Microcorycia are distinguishable by size, shape, color, and characteristic structures of the upper test part. Their size ranges between 23 µm and 160 µm.
Remarks: Our knowledge of the ecology and geographical distribution of the genus Microcorycia is quite fragmentary. This is evident from the fact that as many as six of the 12 species described so far have not been rediscovered since their first description. Another two species that had been missing for 85 years were rediscovered only recently.