species Uniomerus tetralasmus (Say, 1831): synonymy

Unio tetralasmus Say, 1831

Say, 1831. Amer. Conch. 3: pl. 23.
Type(s): TYPE LOST XXX_UNKNOWN, Bayou St. John, near New Orleans.

Unio (sec. Uniomerus) tetralasmus — Simpson (1900), Simpson (1914)
Unio (s.s.) tetralasmus — Call (1900)
Uniomerus tetralasmus — Ortmann (1912), Utterback (1915), Murray & Leonard (1962), Haas (1969), Haas (1969), ... Dai et al. (2025), Chen et al. (2025), FMCS (2025), Cummings et al. (2025), Campbell & Lydeard (2026)
Elliptio (Uniomerus) tetralasmus — Frierson (1927), Haas (1929)
Elliptio (sec. Uniomerus) tetralasmus — Thiele (1934)
Uniomerus tretalasmus [sic] — Contreras-Arquieta (2000)
U. tetralasmus — Marshall et al. (2018)

Unio camptodon Say, 1832

Say, 1832. Amer. Conch. 5: pl. 42.
Type(s): TOPOTYPE USNM_85354, New Orleans, La.

Unio (sec. Uniomerus) tetralasmus var. camptodon — Simpson (1900), Simpson (1914)
Unio (s.s.) tetralasmus — Call (1900)
Uniomerus tetralasmus comptodon [sic] — Utterback (1915)
Elliptio (Uniomerus) tetralasmus-camptodon — Frierson (1927)
Uniomerus tetralasmus — Murray & Leonard (1962), Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), R.I. Johnson (1980), Oesch (1984), Vidrine (1993), Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio sayanus ‘Ward’ of Authors

(error for Unio sayii Ward in Tappan, 1839)
‘Ward’ of Authors.
Conrad, 1838. Monogr. Fam. Unionidae 2(11): 102, pl. 56, fig. 2.
B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [5].

Unio (sec. Uniomerus) tetralasmus var. sayi — Simpson (1900), Simpson (1914)
Unio (s.s.) tetralasmus — Call (1900)
Elliptio (Uniomerus) tetralasmus-sayi — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), Parmalee & Bogan (1998), Williams et al. (2008)
Uniomerus declivis — Watters et al. (2009)

Unio sayii Ward in Tappan, 1839

Ward in Tappan, 1839. Amer. J. Sci. 35: 268, pl. 3, fig. 1.
Type(s): POSSIBLE SYNTYPE USNM_85356, Scioto R., Ohio.

Unio (sec. Uniomerus) tetralasmus var. sayi — Simpson (1900), Simpson (1914)
Unio (s.s.) tetralasmus — Call (1900)
Uniomerus tetralasmus — Utterback (1915), Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), R.I. Johnson (1980), Oesch (1984), Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)
Elliptio (Uniomerus) tetralasmus-sayi — Frierson (1927)
Uniomerus tetralasmus sayi — F.C. Baker (1928)

Unio parallelus Conrad, 1841

(renamed Unio porrectus Conrad, 1854; homonym of Unio parallelus Sowerby, 1840; correct name for Unio paralellus Conrad, 1841)
Conrad, 1841. Proc. Acad. Nat. Sci. 1: 20 [as ‘paralellus’].
Conrad, 1854. Jour. Acad. Nat. Sci. 2(4): 297 [as ‘parallelus’].

Unio (sec. Uniomerus) tetralasmus — Simpson (1900), Simpson (1914)
Elliptio (Uniomerus) tetralasmus — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio symmetricus Lea, 1845

Lea, 1845. Proc. Amer. Phil. Soc. 4: 164.
Lea, 1848. Trans. Amer. Phil. Soc. 10 [O. 4]: 73 [47], pl. 4, fig. 11.
Type(s): HOLOTYPE USNM_85604, Alexandria, La.

Unio (sec. Uniomerus) tetralasmus — Simpson (1900), Simpson (1914)
Unio (s.s.) tetralasmus — Call (1900)
Elliptio (Uniomerus) tetralasmus — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Vidrine (1993), Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008)
Uniomerus declivis — Watters et al. (2009)

Unio rivularis Conrad, 1853

‘Say’ Conrad, 1836. Monogr. Fam. Unionidae 1(5): 45, pl. 23, fig. 1 [as ‘U. declivis’].
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 257.
Conrad, 1854. Jour. Acad. Nat. Sci. 2(4): 296.
Type(s): HOLOTYPE ANSP_42852, small creek in Greene Co., Ala.

Unio (sec. Uniomerus) obesus — Simpson (1900), Simpson (1914)
Elliptio (Uniomerus) obesus — Frierson (1927)
Uniomerus obesus — Clench & Turner (1956), Haas (1969)
Uniomerus tetralasmus — R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio porrectus Conrad, 1854

(new name for Unio parallelus Conrad, 1841; homonym of Unio porrectus Sowerby, 1829)
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 268. [nomen nudum]
Conrad, 1854. Jour. Acad. Nat. Sci. 2(4): 296, pl. 26, fig. 7.
Type(s): HOLOTYPE ANSP_42847, Jackson, Miss.

Unio (sec. Uniomerus) tetralasmus — Simpson (1900), Simpson (1914)
Elliptio (Uniomerus) tetralasmus — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio subcroceus Conrad, 1854

Conrad, 1853. Proc. Acad. Nat. Sci. 6: 268. [nomen nudum]
Conrad, 1854. Jour. Acad. Nat. Sci. 2(4): 297, pl. 27, fig. 1.
Type(s): HOLOTYPE ANSP_41406, Canadian Fork, Arkansas River.

Unio (sec. Uniomerus) tetralasmus — Simpson (1900), Simpson (1914)
Unio (s.s.) tetralasmus — Call (1900)
Elliptio (Uniomerus) tetralasmus — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio manubius Gould, 1855

Gould, 1855. Proc. Boston Soc. Nat. Hist. 5: 229.
Type(s): LECTOTYPE MCZ_169447 (by R.I. Johnson, 1964: 108), Chihuahua, 60 mi from Camp Ringgold, Mexico.

Unio (sec. Uniomerus) tetralasmus var. manubius — Simpson (1900), Simpson (1914)
Unio (Uniomerus) manubius — Martens (1900)
Unio (s.s.) tetralasmus — Call (1900)
Elliptio (Uniomerus) tetralasmus-manubius — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Parmalee & Bogan (1998), R.I. Johnson (1999), Williams et al. (2008), Watters et al. (2009), Cummings et al. (2025)

Unio jamesianus Lea, 1857

Lea, 1857. Proc. Acad. Nat. Sci. 9: 84.
Lea, 1858. Jour. Acad. Nat. Sci. 4 [O. 6]: 52 [52], pl. 6, fig. 35.
Type(s): HOLOTYPE USNM_85365, Jackson, Miss.

Unio (sec. Uniomerus) tetralasmus — Simpson (1900), Simpson (1914)
Unio (s.s.) tetralasmus — Call (1900)
Elliptio (Uniomerus) tetralasmus — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Vidrine (1993), Howells et al. (1996), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio electrinus Reeve, 1865

Reeve, 1865. Conch. Icon. 16: pl. 25, sp. 121.

Unio (sec. Uniomerus) tetralasmus var. sayi — Simpson (1900), Simpson (1914)
Elliptio (Uniomerus) tetralasmus-sayi — Frierson (1927)
Uniomerus tetralasmus — Haas (1969), R.I. Johnson (1970), R.I. Johnson (1972), Burch (1975), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio manubrius ‘Gould’ of Authors

(error for Unio manubius Gould, 1855)
‘Gould’ of Authors.
Paetel, 1890. Cat. Conch.-Samml. 3: 158.
Call, 1895. Trans. Acad. Sci. St. Louis 7: 53.
Call, 1900. Ind. Dept. Geol. Nat. Res. (1899): 518.

Unio (sec. Uniomerus) tetralasmus var. manubius — Simpson (1900), Simpson (1914)
Uniomerus tetralasmus — Parmalee & Bogan (1998), Watters et al. (2009)

Uniomerus tetralasma comptodon Utterback, 1915

(error for Unio camptodon Say, 1832)
Utterback, 1915. Amer. Midl. Nat. 4(3): 48.
Utterback, 1915. Amer. Midl. Nat. 4(6): 247.

Uniomerus tetralasmus — Parmalee & Bogan (1998), Watters et al. (2009)

Unio declivis Conrad, 1836

(misidentified reference to Unio declivis Say, 1831)
‘Say’ Conrad, 1836. Monogr. Fam. Unionidae 1(5): 45, pl. 23, fig. 1.
Conrad, 1838. Monogr. Fam. Unionidae 2(11): back cover correginda [as ‘U. sayanus Ward’].

Unio (sec. Uniomerus) obesus — Simpson (1900), Simpson (1914)
Uniomerus tetralasmus — Utterback (1915), R.I. Johnson (1970), R.I. Johnson (1972), Parmalee & Bogan (1998), Watters et al. (2009)
Elliptio (Uniomerus) tetralasmus — Frierson (1927)

Unio paralellus Conrad, 1841

(incorrect original spelling of Unio parallelus Conrad, 1841)
Conrad, 1841. Proc. Acad. Nat. Sci. 1: 20.

Unio rhomboidius Lea, 1852

(intro'd as syn of Unio camptodon Say, 1832)
‘Ward MSS’ Lea, 1852. Synopsis Fam. Naiades: 32. [nomen nudum]

Unio camptodon Stearns, 1891

(reference to Unio camptodon Say, 1832)
Stearns, 1891. Proc. U.S. Nat. Mus. 14 (844): 105.

Unio (sec. Uniomerus) tetralasmus var. camptodon — Simpson (1900)

Unio electricus Haas, 1969

(error for Unio electrinus Reeve, 1865)
‘Reeve’ Haas, 1969. Das Tierreich 88: 209.

Uniomerus tretalasmus Contreras-Arquieta, 2000

(error for Unio tetralasmus Say, 1831)
‘Say’ Contreras-Arquieta, 2000. Mexicoa 2(1): 45.