C. gibbosa, after Van Oye, 1949
Cyclopyxis gibbosa Van Oye, 1949 *)
Basionym: Cyclopyxis arcelloides var. gibbosa Van Oye, 1949
Diagnosis: The dimensions and domed shape of the shell separate this species from all those with which it has certain common characteristics. It most closely resembles C. eurystoma, but differs in size. The ventral side of the test never carries larger stones, as is usually the case for C. eurystoma.
Dimensions: According to Van Oye (1949): Shell diameter 32.5 µm; height 30 µm; pseudostome diameter 10 µm. My measurements: Diameter 30.6 µm; height 31.5 µm; pseudostome diameter 10.6 µm (n=1).
Ecology.. Form with an aquatic tendency.
Geographical distribution: Java, Indonesia.
C. gibbosa, fen, Mongolia, 2023
*) Cyclopyxis arcelloides var. gibbosa Van Oye, 1949 changed to Cyclopyxis gibbosa Van Oye, 1949.
Note: A formal change is not required in this case according to the International Code of Zoological Nomenclature: (1) According to article 45.6.3, as the name was published before 1961 using the abbreviation var., it is deemed to be subspecific rather than infra-subspecific and therefore falls under rulings for species-group nominal taxa (Chapter 10). (2) According to article 46.1, names established at either species ranks (species or subspecies) are simultaneously established at the other rank, with same author and same type. Authority thus is unchanged.