Unio calamitarum Morelet, 1849
Morelet, 1849. Test. Nov. 1: 30.
Type(s): LECTOTYPE BMNH_93-2-4-2010 (by R.I. Johnson, 1971: 80), Baluntie, near Palenque.

Nephronaias calimatarum [sic] — Simpson (1900)
Unio (Simonaias) cuprinus — Martens (1900)
Nephronaias calamitarum — Ihering (1901), Simpson (1914), Goodrich & van der Schalie (1937), Graf & Cummings (2007), Bogan (2010), Graf & Cummings (2021), Czaja et al. (2023), Cummings et al. (2025)
Elliptio calamitarum — Ortmann (1921)
Elliptio (Nephronaias) calamitarum — Frierson (1927), Haas (1929)
Nephronaias (s.s.) calamitarum — Haas (1969)
Nephronaias (s.s.) scamnata — Johnson (1981)

Unio persulcatus Lea, 1859
Lea, 1859. Proc. Acad. Nat. Sci. 11: 153.
Lea, 1860. Jour. Acad. Nat. Sci. 4 [O. 7]: 255 [73], pl. 40, fig. 135.
Type(s): HOLOTYPE (MONOTYPY) BMNH_1900-3-19-22, Mexico.

Nephronaias persulcatus — Simpson (1900), Frierson (1917)
Unio (Simonaias) cuprinus var. persulcatus — Martens (1900)
Nephronaias tabascoensis — Ihering (1901)
Nephronaias persulcata — Simpson (1914)
Elliptio (Nephronaias) persulcatus — Frierson (1927)
Elliptio (Nephronaias) rugulosa — Haas (1929)
Nephronaias (s.s.) calamitarum — Haas (1969)
Nephronaias calamitarum — Cummings et al. (2025)

Unio calamitarum var. B prolongata Fischer & Crosse, 1894
Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 613, pl. 63, figs. 5-5a.
(intro'd as intra-sp. of Unio calamitarum Morelet, 1849)
Type(s): HOLOTYPE (MONOTYPY) BMNH_93-2-4-2008, Baluntie, near Palenque.

Unio (Simonaias) cuprinus var. tabascoensis — Martens (1900)
Nephronaias tabascoensis — Ihering (1901)
— Simpson (1914)
Elliptio (Nephronaias) calamitarum-prolongus [sic] — Frierson (1927)
Elliptio (Nephronaias) calamitarum — Haas (1929)
Nephronaias (s.s.) calamitarum — Haas (1969)
Nephronaias (s.s.) scamnata — Johnson (1981)
Nephronaias calamitarum — Cummings et al. (2025)

Unio calamitarum var. D nephretica Fischer & Crosse, 1894
Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 612.
(intro'd as intra-sp. of Unio calamitarum Morelet, 1849)
Type(s): HOLOTYPE (MONOTYPY) BMNH_1907-12-30-377, Baluntie, near Palenque.

Unio (Simonaias) cuprinus var. nephritica [sic] — Martens (1900)
— Simpson (1900)
Nephronaias calamitarum var. nephritica [sic] — Simpson (1914)
Nephronaias (s.s.) calamitarum — Haas (1969)
Nephronaias calamitarum — Cummings et al. (2025)

Unio calamitarum var. G arcuans Fischer & Crosse, 1894
Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 612, pl. 64, figs. 5-5a.
(intro'd as intra-sp. of Unio calamitarum Morelet, 1849)
Type(s): HOLOTYPE (MONOTYPY) BMNH_93-2-4-2009, Baluntie, near Palenque.

Unio (Simonaias) cuprinus var. arcuans — Martens (1900)
— Simpson (1900)
Nephronaias calamitarum var. arcuans — Simpson (1914)
Elliptio (Nephronaias) dysoni — Frierson (1927)
Nephronaias (s.s.) calamitarum — Haas (1969)
Nephronaias calamitarum — Cummings et al. (2025)

Unio cuprinus Martens, 1900
‘Lea’ Martens, 1900. Biol. Centr.-Amer., Moll.: 505.
(misidentified reference to Unio cuprinus Lea, 1831)

Nephronaias calamitarum — Simpson (1914)

Unio calamitarum var. nephritica Martens, 1900
‘Crosse & Fischer’ of Authors.
Martens, 1900. Biol. Centr.-Amer., Moll.: 505.
Simpson, 1914. Descr. Cat. Naiades: 281.
(error for Unio calamitarum var. D nephretica Fischer & Crosse, 1894)

Unio calimatorum Lea, 1852
‘Morelet’ Lea, 1852. Synopsis Fam. Naiades: 39.
‘Morelet’ Lea, 1870. Synopsis Fam. Naiades: 63.
‘More.’ B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [2].
(error for Unio calamitarum Morelet, 1849)

Unio calamitarum Sowerby, 1868
‘Morelet’ Sowerby, 1868. Conch. Icon. 16: pl. 74, sp. 385.
(reference to Unio calamitarum Morelet, 1849)

Unio (Simonaias) cuprinus var. arcuans — Martens (1900)
Nephronaias calimatarum [sic] — Simpson (1900)
Nephronaias calamitarum var. nephritica [sic] — Simpson (1914)

Nephronaias calimatarum Simpson, 1900
‘Morelet’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 596.
(error for Unio calamitarum Morelet, 1849)

Nephronaias calamitarum — Simpson (1914)

Unio mexicanus Martens, 1900
‘Parreyss, in Mus. Berol.’ Martens, 1900. Biol. Centr.-Amer., Moll.: 505.
(intro'd as syn of Unio persulcatus Lea, 1859)

Unio (Simonaias) cuprinus var. persulcatus — Martens (1900)

Unio calamitarum var. prolongus Frierson, 1927
‘C. & F.’ Frierson, 1927. Check List N. Amer. Naiades: 36.
(error for Unio calamitarum var. B prolongata Fischer & Crosse, 1894)