Cryptodifflugia angustioris  Tarnogradsky, 1959 *)
Basionym: Cryptodifflugia compressa var. angustioris Tarnogradsky, 1959

Diagnosis: Shell differing from the typical form by its more elongated shape, with an oval aperture; laterally compressed; golden‑brown.

Dimensions: Shell length 19–20 μm; shell width 15–17 μm.

Ecology: In Sphagnum.

Distribution: Russia (Caucasus); Belgium; Germany; Spitsbergen.

References: Bobrov, A., Mazei, Y., 2017. A review of testate amoeba genus Cryptodifflugia Penard, 1890 (Phryganellina: Cryptodifflugiidae) with a key to species. Zootaxa 4282 (2): 292–308.

*) Taxonomic Note: Cryptodifflugia compressa var. angustioris Tarnogradsky, 1959, is changed to Cryptodifflugia angustioris Tarnogradsky, 1959.
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 Cryptodifflugia gangustioris Tarnogradsky, 1959.