Pisidium variabile Prime, 1852
Prime, 1852. Proc. Boston Soc. Nat. Hist. 4: 163.
Prime, 1852. Boston J. Nat. Hist. 6(3): 351, pl. 11, figs. 7-9.
Prime, 1865. Smithsonian Misc. Coll. (145): 66, figs. 69-70.

Pisidium variabile — Herrington (1962), Mackie et al. (1980), Turgeon et al. (1998), Schultheiß et al. (2008), Bogan (2010), IUCN (2011), Stunžėnas et al. (2011), ITIS (2012), Clewing et al. (2013), Saito et al. (2022)
Pisidium (Cyclocalyx) variabile — Clarke (1973), Burch (1975), Cooley & Ó Foighil (2000), Bespalaya et al. (2017), Fuentealba-Jara et al. (2017)
Cyclocalyx variabile — Lee & Ó Foighil (2003)
Euglesa (Cyclocalyx) variabile — Mouthon & Forcellini (2017)
Euglesa variabile — Vinarski et al. (2020)
Euglesa (Casertiana) variabilis — Bespalaya et al. (2023)

Pisidium cicer Prime, 1858
Prime, 1858. Ann. Lyc. Natur. Hist. 6: 64, pl. 1, figs. 1a-c.

Pisidium variabile — Herrington (1962)
Pisidium (Cyclocalyx) variabile — Burch (1975)

Pisidium mirabile Clessin, 1877
‘Whittemore’ Clessin, 1877. Conch. Cab. 9(3): 49, pl. 6, figs. 1-3.

Pisidium (Cyclocalyx) variabile — Burch (1975)

Pisidium variabile var. brevius Sterki, 1906
Sterki, 1906. Nautilus 19(10): ??.
(intro'd as intra-sp. of Pisidium variabile Prime, 1852)

Pisidium (Cyclocalyx) variabile — Burch (1975)

Pisidium variabile var. hybridum Sterki, 1906
Sterki, 1906. Nautilus 19(10): ??.
(intro'd as intra-sp. of Pisidium variabile Prime, 1852)

Pisidium (Cyclocalyx) variabile — Burch (1975)

Pisidium variabile var. magnum Sterki, 1916
Sterki, 1916. Ann. Carnegie Mus. 10(3/4): ??.
(intro'd as intra-sp. of Pisidium variabile Prime, 1852)

Pisidium (Cyclocalyx) variabile — Burch (1975)

Pisidium decisum Sterki, 1922
Sterki, 1922. Ann. Carnegie Mus. 13(3/4): ??.

Pisidium variabile — Herrington (1962)
Pisidium (Cyclocalyx) variabile — Burch (1975)

Pisidium probum Sterki, 1923
Sterki, 1923. Nautilus 37(1): ??.

Pisidium variabile — Herrington (1962)
Pisidium (Cyclocalyx) variabile — Burch (1975)

Cyclas nitida Linsley, 1845
Linsley, 1845. Amer. J. Sci. 48(2): 276.
(misidentified reference to Cyclas nitida Mighels & Adams, 1842)

Pisidium grande Prime, 1865
‘Whittemore, in litt.’ Prime, 1865. Smithsonian Misc. Coll. (145): 66. [nomen nudum]
‘Whittemore, in litt.’ Prime, 1870. Amer. J. Conch. 5: 173. [nomen nudum]
(intro'd as syn of Pisidium variabile Prime, 1852)

Pisidium (Cyclocalyx) variabile — Burch (1975)

Pisidium palustre Prime, 1870
‘Lewis, in litt.’ Prime, 1870. Amer. J. Conch. 5: 173. [nomen nudum]
(intro'd as syn of Pisidium variabile Prime, 1852)

Pisidium (Cyclocalyx) variabile — Burch (1975)