Obliquaria (Rotundaria) subrotunda Rafinesque, 1820
Rafinesque, 1818. Amer. Mon. Mag. 3: 355 [as ‘Potamilus subrotundus’]. [nomen nudum]
Rafinesque, 1819. Jour. Phys. Chim. Hist. Nat. 88: 426 [as ‘U. (Obovaria) subrotunda’]. [nomen nudum]
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 308, pl. 81, figs. 21-23 [also as ‘U. subrotunda’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 23, 29, 52.
Type(s): NEOTYPE ANSP_20254, Kentucky River.

— Simpson (1900), Simpson (1914)
Obovaria subrotunda — Vanatta (1915), Ortmann & Walker (1922), Burch (1975), Gordon et al. (1979), R.I. Johnson (1980), ... Gasparini et al. (2020), Graf & Cummings (2021), FMCS (2021), Hopper et al. (2023), Hauck et al. (2023)
Obovaria (s.s.) subrotunda — Ortmann (1918), Ortmann (1924), Ortmann (1925), Frierson (1927), Haas (1930), Haas (1969)
Rotundaria subrotunda — Thiele (1934)

Obovaria striata Rafinesque, 1820
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 311 [also as ‘Unio striata’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 54.

Obovaria striata — Simpson (1900), Simpson (1914)
Obovaria subrotunda — Vanatta (1915), Ortmann & Walker (1922), Burch (1975), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)
Quadrula (Striata) striata — Frierson (1927)
Quadrula (Luteacarnea) striata — Haas (1969), Haas (1969)
Plethobasus striatus — Morrison (1969)
Plethobasus cooperianus — R.I. Johnson (1980)

Obovaria striata var. rosea Rafinesque, 1820
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 311.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 55.
(intro'd as intra-sp. of Obovaria striata Rafinesque, 1820)

— Vanatta (1915)

Obovaria striata var. tuberculata Rafinesque, 1820
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 311.
Rafinesque, 1864. [in] Binney & Tryon, reprint: 55.
(intro'd as intra-sp. of Obovaria striata Rafinesque, 1820)

Unio (Aximedia) levigata Rafinesque, 1820
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 296, pl. 80, fig. 11-13 [also as ‘Elliptio levigata’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 42.
Type(s): LECTOTYPE ANSP_20255, Kentucky River.

— Simpson (1900), Simpson (1914), Ortmann & Walker (1922), Burch (1975)
Obovaria levigata — Vanatta (1915)
Obovaria (s.s.) subrotunda levigata — Ortmann (1918)
Obovaria (s.s.) levigata — Frierson (1927), Haas (1969)
Obovaria subrotunda — R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio (Aximedia) zonalis Rafinesque, 1820
Rafinesque, 1818. Amer. Mon. Mag. 3: 355 [as ‘Potamilus zonalis’]. [nomen nudum]
Rafinesque, 1820. Ann. Gén. Sci. Phys. 5 (13): 297 [also as ‘Elliptio zonalis’].
Rafinesque, 1864. [in] Binney & Tryon, reprint: 22, 42.

— Simpson (1900), Simpson (1914), Vanatta (1915)
Obovaria (s.s.) subrotunda — Frierson (1927), Haas (1969)

Unio orbiculatus Hildreth, 1828
Hildreth, 1828. Amer. J. Sci. 14: 284.

Lampsilis (sec. Eurynia) orbiculatus — Simpson (1900)
Unio (s.s.) orbiculatus — Call (1900)
Lampsilis orbiculata — Ortmann (1909), Ortmann (1909), Ortmann (1910), Ortmann (1912), Ortmann (1918), Ortmann (1924), Ortmann (1925), Stansbery (1970), Burch (1975), Gordon et al. (1979), Oesch (1984), ITIS (2012)
Lampsilis (Eurynia) orbiculata — Simpson (1914)
Obovaria (s.s.) retusa — Frierson (1927), Haas (1969)
Lampsilis abrupta — Vidrine (1993), Strayer & Jirka (1997), Parmalee & Bogan (1998), Watters et al. (2009)
Obovaria subrotunda — Williams et al. (2008), Watters et al. (2009)

Unio rotundus Wood, 1828
Wood, 1828. Suppl. Index Testac.: 2 [as ‘Mya rotunda’].
Wood, 1828. Suppl. Index Testac.: 57, pl. 1, sp. 1 [as ‘Unio rotundatus’].
Wood in Hanley, 1856. Index Testac.: 199, pl. 1, fig. 1.
(homonym of Diplodon rotundus Wagner, 1827)

Obovaria (s.s.) circulus — Simpson (1900), Simpson (1914)
Obovaria (s.s.) subrotunda — Frierson (1927), Haas (1969)
Obovaria subrotunda — Parmalee & Bogan (1998), Watters et al. (2009)

Unio circulus Lea, 1829
Lea, 1829. Trans. Amer. Phil. Soc. 3 [O. 1]: 433 [47], pl. 9, fig. 14.
Type(s): UNKNOWN USNM_85734, Cincinatti, Ohio.

Obovaria (s.s.) circulus — Simpson (1900), Simpson (1914)
Unio (s.s.) circulus — Call (1900)
Obovaria circulus — Ortmann (1909), Ortmann (1909), Ortmann (1909), Ortmann (1910), Ortmann (1912)
Unio circulus — de Gregorio (1914)
Obovaria subrotunda — Vanatta (1915), Ortmann & Walker (1922), Burch (1975), Vidrine (1993), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)
Obovaria (s.s.) subrotunda — Ortmann (1918), Ortmann (1925), Frierson (1927), Haas (1969)

Unio lens Lea, 1831
Lea, 1831. Trans. Amer. Phil. Soc. 4 [O. 1]: 80, pl. 8, fig. 10.

Obovaria (s.s.) lens — Simpson (1900), Simpson (1914)
Unio (s.s.) circulus — Call (1900)
Obovaria circulus — Ortmann (1909), Ortmann (1912)
— de Gregorio (1914)
Obovaria levigata — Vanatta (1915)
Obovaria (s.s.) subrotunda levigata — Ortmann (1918)
Obovaria lens — Ortmann & Walker (1922)
Obovaria (s.s.) subrotunda lens — Ortmann (1924), Ortmann (1925)
Obovaria (s.s.) levigata — Frierson (1927), Haas (1969)
Obovaria subrotunda — R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio laevigatus Say, 1834
‘Rafinesque’ of Authors.
Say, 1834. Amer. Conch. 6: [no pagination].
Conrad, 1834. New Fresh-Water Shells: 70.
Ferussac, 1835. Mag. Zool. 5: 28.
Lea, 1836. Synopsis Fam. Naiades: 59.
Lea, 1852. Synopsis Fam. Naiades: 57.
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 251.
Ortmann, 1921. Mem. Carnegie Mus. 8: 92.
(error for Unio (Aximedia) levigata Rafinesque, 1820)

Obovaria (s.s.) lens — Simpson (1900), Simpson (1914)
Obovaria lens — Ortmann & Walker (1922)
Obovaria subrotunda — Parmalee & Bogan (1998), Watters et al. (2009)

Unio suborbiculatus Conrad, 1836
‘Hildreth’ of Authors.
Conrad, 1836. Monogr. Fam. Unionidae 1(4): 35.
Mörch, 1853. Cat. Conch. Yoldi 2: 46.
(error for Unio orbiculatus Hildreth, 1828)

Unio leibii Lea, 1862
Lea, 1862. Proc. Acad. Nat. Sci. 14: 168.
Lea, 1866. Jour. Acad. Nat. Sci. 6 [O. 11]: 44 [48], pl. 15, fig. 42.
Type(s): HOLOTYPE USNM_84425, Michigan.

Obovaria (s.s.) leibii — Simpson (1900), Simpson (1914)
Unio (s.s.) circulus — Call (1900)
Obovaria (s.s.) subrotunda — Frierson (1927), Haas (1969)
Obovaria subrotunda — Strayer & Jirka (1997), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio depygis Conrad, 1866
Conrad, 1866. Amer. J. Conch. 2: 107, pl. 10, fig. 1.

Obovaria (s.s.) lens var. depygis — Simpson (1900), Simpson (1914)
Obovaria (s.s.) subrotunda lens — Ortmann (1924)
Obovaria (s.s.) subrotunda-depygis — Frierson (1927)
Obovaria (s.s.) subrotunda — Haas (1969)
Obovaria subrotunda — Burch (1975), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio zonata Simpson, 1900
‘Rafinesque’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 744.
Simpson, 1914. Descr. Cat. Naiades: 731.
Frierson, 1927. Check List N. Amer. Naiades: 90.
(error for Unio (Aximedia) zonalis Rafinesque, 1820)

Obovaria lens var. elongata Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 294.
(intro'd as intra-sp. of Unio lens Lea, 1831)

Obovaria (s.s.) lens var. elongata — Simpson (1914)
Obovaria (s.s.) levigata — Haas (1969)
Obovaria subrotunda — R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Obovaria lens var. parva Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 294.
(intro'd as intra-sp. of Unio lens Lea, 1831)
Type(s): LECTOTYPE USNM_150457, Duck Riv., Tenn.

Obovaria (s.s.) lens var. parva — Simpson (1914)
Obovaria (s.s.) levigata — Frierson (1927), Haas (1969)
Obovaria subrotunda — R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Obovaria subrotunda globula Morrison, 1942
Morrison, 1942. Bulletin Bur. Amer. Ethnol. 129: 360.
(intro'd as intra-sp. of Obliquaria (Rotundaria) subrotunda Rafinesque, 1820)
Type(s): HOLOTYPE USNM_85769, Tuscumbia, Alabama.

Obovaria (s.s.) subrotunda — Haas (1969)
Obovaria subrotunda — R.I. Johnson (1980), Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009)

Unio suborbiculatus of Authors, unknown year
Kuster, 1857 of Authors.
(reference to Unio suborbiculatus Conrad, 1836)

Lampsilis (Ortmanniana) abruptus — Frierson (1927)

Unio rotundatus Wood, 1828
Wood, 1828. Suppl. Index Testac.: 57.
(error for Unio rotundus Wood, 1828)

Unio subrotundus Ferussac, 1835
‘selon Say’ Ferussac, 1835. Mag. Zool. 5: 26.
(reference to Obliquaria (Rotundaria) subrotunda Rafinesque, 1820)

Obovaria (s.s.) circulus — Simpson (1900), Simpson (1914)

Margarita (Unio) orbiculatus Lea, 1836
‘Hild.’ Lea, 1836. Synopsis Fam. Naiades: 25.
(reference to Unio orbiculatus Hildreth, 1828)

Lampsilis (sec. Eurynia) orbiculatus — Simpson (1900)
Lampsilis (Eurynia) orbiculata — Simpson (1914)
Lampsilis (Ortmanniana) abruptus — Frierson (1927)
Lampsilis (Ortmanniana) abrupta — Haas (1969)
Lampsilis abruptus — Morrison (1969)
Lampsilis abrupta — R.I. Johnson (1980), Parmalee & Bogan (1998)