Unio (Leptodea) fragilis Rafinesque, 1820
Rafinesque, 1818, Amer. Mon. Mag. 3: 355 [‘Potamilus fragilis’]. [nomen nudum]
Rafinesque, 1820, Ann. Gén. Sci. Phys. 5 (13): 295.
Rafinesque, 1864, [in] Binney & Tryon, reprint: 22, 41.
Type(s): LECTOTYPE ANSP_20209, creeks, Kentucky.

Unio (Leptodea) fragilis var. fuscata Rafinesque, 1820
Rafinesque, 1820, Ann. Gén. Sci. Phys. 5 (13): 295.
Rafinesque, 1864, [in] Binney & Tryon, reprint: 41.
(intro'd as intra-sp. of Unio (Leptodea) fragilis Rafinesque, 1820; homonym of Unio (Elliptio) viridis var. fuscata Rafinesque, 1820)

Unio fragilis Swainson, 1823
‘Rafinesque’ of Authors.
Swainson, 1823, Zool. Illustr. 3(1): pl. 171.
Conrad, 1836, Monogr. Fam. Unionidae 1(6): 55, pl. 30.
(reference to Unio (Leptodea) fragilis Rafinesque, 1820)

Unio gracilis Barnes, 1823
Barnes, 1823, Amer. J. Sci. 6 (1-2): 274.

Unio planus Barnes, 1823
Barnes, 1823, Amer. J. Sci. 6 (1-2): 272, text fig. 16.
(homonym of Unio planus Studer, 1820)

Unio (Niaa) atrata Swainson, 1823
Swainson, 1823, Zool. Illustr. 3(1): pl. 171.

Mya plana Eaton, 1826
‘Barnes’ Eaton, 1826, Zool. Text-Book: 221.
(reference to Unio planus Barnes, 1823)

Lasmonos fragilis Rafinesque, 1831
Rafinesque, 1831, Continuation: 5.
Rafinesque, 1864, [in] Binney & Tryon, reprint: 81.
(homonym of Unio (Leptodea) fragilis Rafinesque, 1820)

Margarita (Unio) atratus Lea, 1836
‘Swain.’ Lea, 1836, Synopsis Fam. Naiades: 31.
Lea, 1852, Synopsis Fam. Naiades: 33.
(reference to Unio (Niaa) atrata Swainson, 1823)

Unio leptodea var. planus Jay, 1850
‘Barnes’ Jay, 1850, Cat. Rec. Shells: 61.
(reference to Unio planus Barnes, 1823)

Lampsilis simpsoni Ferriss, 1900
Ferriss, 1900, Nautilus 14: 38, text fig.

Lampsilis gracilis lacustris F.C. Baker, 1922
F.C. Baker, 1922, Nautilus 35(4): 131.
F.C. Baker, 1928, Bull. Wisconsin Geol. Nat. Hist. Survey 70(2): 237, pl. 80, figs. 5-7; pl. 81, figs. 1-2.
(intro'd as intra-sp. of Unio gracilis Barnes, 1823)
Type(s): HOLOTYPE (ORIG. DESIG.) UMMZ_209186, L. Butte de Morts, Wisc.

Medionidus mcglameriae van der Schalie, 1939
van der Schalie, 1939, Occ. Pap. Mus. Zool. Univ. Mich. (407): 1, pl. 1, figs. 1-3.
Type(s): HOLOTYPE UMMZ_130460, Tombigbee River, Epes, Sumpter Co., Alabama.

Medionidus macglameriae Turgeon et al., 1988
‘van der Schalie’ of Authors.
Turgeon et al., 1988, Am. Fisher. Soc. Spec. Publ. (16): 31.
Williams et al., 1993, Fisheries 18(9): 13.
(error for Medionidus mcglameriae van der Schalie, 1939)

Unio plantus Williams et al., 2008
‘Barnes’ Williams et al., 2008, Freshw. Mussels AL and Mobile Basin: 419.
(error for Unio planus Barnes, 1823)