Cyclopyxis parvula
C. parvula from Bonnet & Thomas 1960

Cyclopyxis parvula  Bonnet & Thomas, 1960  *)
Basionym: Cyclopyxis eurystoma var. parvula  Bonnet & Thomas, 1960

Diagnosis: Shell shaped like an Arcella, with mineral grains and small in size. In side view the test has a high dome, about three-quarters of its diameter. In ventral view circular, rarely a little elliptical; pseudostome large, about the test diameter, with a slight invagination, as in the type. Shell covered with mineral grains, fragmented, sometimes not very abundant. The top of the dome is often covered with quartz elements that are larger than elsewhere. The size of this variety is significantly smaller than that of the type, even for larger individuals.

Dimensions: Diameter 30-33 µm, height 23-25 µm, pseudostome diameter 18-20 µm (in Africa, these measurements are respectively 32-52 µm, 30-33 µm and 18-22 µm).

Ecology: Soil mosses (Gironde, France); under Thymus vulgaris L. on the edge of the Massane forest (Pyrénées-Orientales). This variety also exists in Africa: Hoggar, near Oued Tamamassu; Algeria, Algiers region and La Calle region; Uganda (unpublished documents L. Gauthier- Lièvre).

Cyclopyxis parvula
Cyclopyxis cf. parvula, Japan

*) Cyclopyxis eurystoma var. parvula Bonnet & Thomas, 1960 changed to Cyclopyxis parvula  Bonnet & Thomas, 1960.
No new name needs to be established in this case under the International Code of Zoological Nomenclature. Because the name was published before 1961 using the abbreviation var., it is deemed subspecific under Article 45.6.4, unless explicitly proposed as infrasubspecific. As a species-group name, it is simultaneously established at both species and subspecies rank under the Principle of Coordination (Art. 46.1), with the same author, date, and name-bearing type. Accordingly, when treated at species rank, the correct name is Cyclopyxis parvula Bonnet & Thomas, 1960.
Ferry Siemensma, created October 7, 2019; last modified April 29, 2026
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