Anodon chiquetana Simpson, 1900
‘d’Orbigny’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 928.
‘d’Orbigny’ Simpson, 1914. Descr. Cat. Naiades: 1441.
(error for Unio (Anodontes) chiquitana d’Orbigny, 1835)

Anodon javana Simpson, 1900
‘Sowerby’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 588.
Preston, 1912. Rec. Ind. Mus. 7: 282.
Simpson, 1914. Descr. Cat. Naiades: 242.
Haas, 1920. Conch. Cab. 9 (pt. 2, h. 52): 297.
Haas, 1969. Das Tierreich 88: 382.
(error for Anodon javona Sowerby, 1867)

Anodon kellettii Lea, 1870
‘Sowerby’ of Authors.
Lea, 1870. Synopsis Fam. Naiades: 84.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 588.
Preston, 1912. Rec. Ind. Mus. 7: 282.
Simpson, 1914. Descr. Cat. Naiades: 242.
Brandt, 1974. Arch. Moll. 105: 264.
(error for Anodon kelletii Sowerby, 1867)

Anodonta arcuata Martens, 1866
‘Cailliaud’ of Authors.
Martens, 1866. Malak. Blatt. 13: 11.
Jickeli, 1874. Nova Acta Dtsch. Akad. Naturf. 37(1): 265.
Servain, 1890. Bull. Soc. Malac. France 7: 316.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 899.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 87.
Simpson, 1914. Descr. Cat. Naiades: 1336.
Van Damme, 1984. Freshw. Moll. N. Africa (25): 68.
Mandahl-Barth, 1988. Studies on African Freshwater Bivalves: 73.
Ibrahim et al., 1999. EEAA Nat. Biodiv. Unit (10): 109.
(error for Anodonta arcuta Cailliaud, 1823)

Anodonta arkansasensis B.H. Wright, 1888
‘Lea’ of Authors.
B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [6].
Call, 1895. Trans. Acad. Sci. St. Louis 7: 60.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 617.
Simpson, 1914. Descr. Cat. Naiades: 347.
Williams et al., 2008. Freshw. Mussels AL and Mobile Basin: 709.
Watters et al., 2009. Freshw. Mussels OH: 294.
(error for Anodonta arkansensis Lea, 1852)

Anodonta carthagena Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 922.
Simpson, 1914. Descr. Cat. Naiades: 1427.
(intro'd as syn of Anodonta trautwiniana Lea, 1852)

Anodonta cilicia Simpson, 1914
‘Kobelt’ Simpson, 1914. Descr. Cat. Naiades: 371.
(error for Anodonta cilicica Kobelt & Rolle, 1895)

Anodonta dignota Simpson, 1900
‘Rafinesque’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 631 [as by Férussac], 648.
‘Rafinesque’ Simpson, 1914. Descr. Cat. Naiades: 387 [as by Férussac], 437.
(error for Anodonta (Flexiplis?) digonota Rafinesque, 1831)

Anodonta inaequivalvis Simpson, 1900
‘Lea’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 922.
Martens, 1900. Biol. Centr.-Amer., Moll.: 534.
Simpson, 1914. Descr. Cat. Naiades: 1423.
Mansur et al., 2020. [in] Damborenea, Rogers & Thorp, Freshw.Invert. Neotrop. 5: 424.
(error for Anodonta inaequivalva Lea, 1868)

Anodonta intermerata Paetel, 1890
‘Heude’ of Authors.
Paetel, 1890. Cat. Conch.-Samml. 3: 183.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 639.
Preston, 1912. Rec. Ind. Mus. 7: 284.
Simpson, 1914. Descr. Cat. Naiades: 405.
(error for Anodon intemerata Heude, 1885)

Anodonta linneana Conrad, 1853
‘Lea’ of Authors.
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 264.
Hanley, 1856. Illustr. Descr. Cat. Rec. Bivalve Shells: 387.
Sowerby, 1870. Conch. Icon. 17: pl. 35, sp. 144.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 646.
Simpson, 1914. Descr. Cat. Naiades: 431.
Frierson, 1927. Check List N. Amer. Naiades: 14.
Haas, 1969. Das Tierreich 88: 364.
Parmalee & Bogan, 1998. The Freshwater Mussels of Tennessee: 206.
Watters et al., 2009. Freshw. Mussels OH: 260.
(error for Anodonta linnaeana Lea, 1852)

Anodonta marryattana Conrad, 1853
‘Lea’ of Authors.
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 264.
Sowerby, 1870. Conch. Icon. 17: pl. 28, sp. 111.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 642.
Simpson, 1914. Descr. Cat. Naiades: 422.
F.C. Baker, 1928. Bull. Wisconsin Geol. Nat. Hist. Survey 70(2): 157.
Haas, 1969. Das Tierreich 88: 365.
(error for Anodonta maryattana Lea, 1840)

Anodonta ohioensis Agassiz, 1852
‘Rafinesque’ of Authors.
Agassiz, 1852. Arch. Naturg. 18(1): 46.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 648.
Simpson, 1914. Descr. Cat. Naiades: 437.
Oesch, 1984. Missouri Naiades: 183 [as ‘Potamilus’].
(error for Anodonta (Lastena) ohiensis Rafinesque, 1820)

Anodonta wahlametensis Simpson, 1900
‘Lea’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 629.
Arnold, 1908. Proc. U.S. Nat. Mus. 34: 355.
Simpson, 1914. Descr. Cat. Naiades: 379.
Henderson, 1935. GSA, Spec. Pap. 3: 66.
Davis & Fuller, 1981. Malacologia 20: 219.
Mock et al., 2004. Molec. Ecol. 13: 1090.
(error for Anodonta wahlamatensis Lea, 1838)

Anodontes sirionis Simpson, 1900
‘d’Orbigny’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 918.
‘d’Orbigny’ Simpson, 1914. Descr. Cat. Naiades: 1407.
(error for Unio (Anodontes) sirionos d’Orbigny, 1835)

Anodontites europae Simpson, 1900
‘Leach’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 624 [as ‘europæ’].
‘Leach’ Simpson, 1914. Descr. Cat. Naiades: 364 [as ‘europæ’].
(error for Anodontes europaea Leach, 1852)

Anodontites (s.s.) trigonus var. pallescens Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1442.
(intro'd as intra-sp. of Anodon trigonus Wagner, 1827)
Type(s): HOLOTYPE (MONOTYPY) USNM_86731, Amazon River.

Brazzaea jourdyi Simpson, 1900
‘Bourguignat’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 907.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 1374.
Simpson, 1914. Descr. Cat. Naiades: 1374.
(error for Brazzaea jouberti Bourguignat, 1886)

Brazzaea lavigerina Simpson, 1900
‘Bourguignat’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 907.
‘Bourguignat’ Simpson, 1914. Descr. Cat. Naiades: 1374.
(error for Brazzaea lavigeriana Bourguignat, 1886)

Burtonia lavigerina Simpson, 1900
‘Bourguignat’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 577.
Simpson, 1914. Descr. Cat. Naiades: 204.
Pain & Woodward, 1968. Rev. Zool. Botan. Afr. 77: 213.
(error for Burtonia lavigeriana Bourguignat, 1886)

Burtonia livingstonensis Simpson, 1900
‘Bourguignat’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 578.
‘Bourguignat’ Simpson, 1914. Descr. Cat. Naiades: 205.
(error for Burtonia livingstoniana Bourguignat, 1883)

Burtonia magnipica Simpson, 1914
‘Bourguignat’ Simpson, 1914. Descr. Cat. Naiades: 204.
(error for Burtonia magnifica Bourguignat, 1886)

Chambardia letourneuxiana Simpson, 1900
‘Bourguignat’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 902.
‘Bourguignat’ Simpson, 1914. Descr. Cat. Naiades: 1350.
(error for Chambardia letourneuxi Servain, 1890)

Columba blainvilleana Ihering, 1890
‘Lea’ of Authors.
Ihering, 1890. Arch. Naturg. 56(1): 142.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 915.
Simpson, 1914. Descr. Cat. Naiades: 1400.
Haas, 1931. Senckenbergiana 13: 102.
Morretes, 1949. Arqu. Mus. Paranaense 7: 28.
Bonetto, 1963. Physis 24: 11.
Parodiz & Bonetto, 1963. Malacologia 1(2): 206.
Modell, 1964. Arch. Moll. 93: 81.
Figueiras, 1965. Comm. Soc. Malac. Uruguay 1(8): 252.
Haas, 1969. Das Tierreich 88: 577.
Haas, 1969. Treatise on Invert. Paleo 1: N465.
Mansur, 1970. Iheringia 39: 55.
Bonetto & Mansur, 1970. Acta Zool. Lilloana 27: 256.
Millard, 2001. Class. Moll. (3): 1074.
Simone, 2006. Land. Freshw. Moll. Brazil.: 289.
(error for Anodonta blainvilliana Lea, 1834)

Cristaria (Crassitesta) radiata Simpson, 1900
Heude, 1881. Conch. Fluv. Nanking (7): pl. 52, fig. 96 [as ‘Dipsas parvus’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 586.
Simpson, 1914. Descr. Cat. Naiades: 236.

Cyprogenia irrorata var. pusilla Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 610.
Simpson, 1914. Descr. Cat. Naiades: 328.
(intro'd as intra-sp. of Unio irroratus Lea, 1828)
Type(s): LECTOTYPE USNM_152004 (by R.I. Johnson, 1975: 18), Mammoth Cave (Green R.), Kentucky.

Diplodon frenzellii Simpson, 1900
‘Ihering’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 882.
Simpson, 1914. Descr. Cat. Naiades: 1264.
(error for Unio frenzelii Ihering, 1893)

Diplodon parallelipipedon d’Orbigny, 1846
‘Lea’ of Authors.
d’Orbigny, 1846. Voyage dans l’Amérique Méridionale 5(3): 609.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 884.
Corsi, 1900. Anais Mus. Nac. Montevideo 2: 447.
Simpson, 1914. Descr. Cat. Naiades: 1274-1275.
Haas, 1930. Senckenbergiana 12: 189.
Morretes, 1949. Arqu. Mus. Paranaense 7: 18.
Parodiz, 1968. Sterkiana 30: 8.
Mansur, 1970. Iheringia 39: 83.
Quintana, 1982. Rev. Mus. Argentino Zoológicas 11: 128.
Simone, 2006. Land. Freshw. Moll. Brazil.: 260.
(error for Unio parallelopipedon Lea, 1834)

Diplodon websteri Simpson, 1902
Simpson, 1902. Nautilus 16: 30.
Simpson, 1914. Descr. Cat. Naiades: 1307.
Type(s): LECTOTYPE USNM_162342 (by McMichael & Hiscock, 1958: 476), Waiuku, New Zealand.

Diplodon (Cyclomya s.s.) fontainianus var. deceptus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1281.
(intro'd as intra-sp. of Unio fontainiana d’Orbigny, 1835)

Diplodon (Hyridella s.s.) menziezi Simpson, 1900
‘Gray’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 889.
‘Gray’ Simpson, 1914. Descr. Cat. Naiades: 1290.
(error for Unio menziesii Gray, 1843)

Diplodon (Hyridella s.s.) menziesi rugulosus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1291.
(new name for Unio rugatus Hutton, 1882; intro'd as intra-sp. of Unio menziesii Gray, 1843)

Diplodon (s.s.) aureus Simpson, 1900
‘Swainson’ Küster, 1861. Conchyl. Cab. 9(2): 161, pl. 46, fig. 3 [as ‘Unio auratus’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 883.
Simpson, 1914. Descr. Cat. Naiades: 1268.

Diplodon (s.s.) iheringi Simpson, 1914
‘Clessin’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 894. [nomen nudum]
‘Clessin’ Simpson, 1914. Descr. Cat. Naiades: 1272.
Type(s): SYNTYPES SMF_11312, Rio Guahyba, Rio Gr. do Sul, Bras.

Diplodon (s.s.) leai Simpson, 1900
‘Fer.’ Lea, 1836. Synopsis Fam. Naiades: 32 [as ‘Margarita (Unio) modestus’]. [nomen nudum]
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 876, footnote.
Simpson, 1914. Descr. Cat. Naiades: 1241.
Type(s): SYNTYPE USNM_85725, Brazil.

Diplodon (s.s.) mimus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1249.
Type(s): SYNTYPE USNM_162425, Iguape, Brazil.

Diplodon (s.s.) perplexus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1248.
Type(s): SYNTYPE USNM_150389, Maldonado, Uruguay.

Diplodon (s.s.) santamariae Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1270 [as ‘santa-mariae’].
Type(s): SYNTYPE USNM_162383, Rio Itapuca, Sta Catherina, Brazil.

Diplodon (s.s.) semigranosus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1252.
Type(s): SYNTYPE USNM_128790, Rio Tiete, near Ponte Grande, Sao Paulo, Brazil.

Diplodon (s.s.) suppositus Simpson, 1914
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 877. [nomen nudum]
Simpson, 1914. Descr. Cat. Naiades: 1245.
Type(s): SYNTYPE USNM_162374, Parana, Brazil.

Diplodon (s.s.) trivialis Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1250.
Type(s): SYNTYPE USNM_162409, Taboticabal [= Jaboticabal], Sao Paulo, Brazil.

Diplodon (s.s.) wagnerianum Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 877.
Simpson, 1914. Descr. Cat. Naiades: 1246 [as ‘wagnerianus’].
(new name for Diplodon ellipticum Wagner, 1827)

Fossula braziliensis Simpson, 1914
‘von Ihering’ Simpson, 1914. Descr. Cat. Naiades: 1398.
‘von Ihering’ Haas, 1931. Senckenbergiana 13: 50.
(error for Fossula brasiliensis Ihering, 1910)

Glabaris (s.s.) philippianus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 919.
Simpson, 1914. Descr. Cat. Naiades: 1416.
(new name for Anodonta subsinuata Philippi, 1869)

Glabaris (s.s.) umbonatus Simpson, 1900
‘Gould’ Sowerby, 1870. Conch. Icon. 17: pl. 29, sp. 115, fig. 115b [as ‘Anodon ciconia’]. [in part]
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 926, footnote.
Simpson, 1914. Descr. Cat. Naiades: 1436.

Glabaris (sec. Virgula) falsus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 932, footnote.
Simpson, 1914. Descr. Cat. Naiades: 1456.
Type(s): HOLOTYPE (MONOTYPY) USNM_86711, Yuruari River.

Glabaris trapesialis var. cygnaeformis Simpson, 1900
‘Pilsbry’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 925.
‘Pilsbry’ Simpson, 1914. Descr. Cat. Naiades: 1432.
(error for Glabaris trapesialis var. cygneiformis Pilsbry, 1896)

Hyridella australis E.A. Smith, 1882
‘Lamarck’ of Authors.
E.A. Smith, 1882. J. Linn. Soc., Zool. 16: 309.
Ortmann, 1912. Nautilus 25(9): 100.
Simpson, 1914. Descr. Cat. Naiades: 1297.
Cotton & Gabriel, 1932. Proc. Roy. Soc. Victoria 44(2): 155, pl. 16, fig. 1.
(misidentified reference to Unio australis Lamarck, 1819)

Lamellidens burmanus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1170.
(new name for Unio pulcher Tapparone Canefri, 1889)

Lamellidens canefrianus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 857, footnote.
Simpson, 1914. Descr. Cat. Naiades: 1176.
(new name for Unio protensus Tapparone Canefri, 1889)

Lamellidens marginalis var. hanleyi Simpson, 1900
Hanley & Theobald, 1872. Conch. Indica (3): 20, pl. 44, fig. 4 [as ‘Unio marginalis var. corriana’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 855.
Simpson, 1914. Descr. Cat. Naiades: 1169.
(intro'd as intra-sp. of Unio marginalis Lamarck, 1819)

Lampsilis australis Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 75, pl. 2, fig. 2.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 544.
Simpson, 1914. Descr. Cat. Naiades: 94.
Type(s): HOLOTYPE USNM_150473, Little Patsaliga Creek, Alabama.

Lampsilis brittsi Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 76, pl. 5, figs. 1-2.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 533.
Simpson, 1914. Descr. Cat. Naiades: 58.
Type(s): HOLOTYPE USNM_152700, Little Niangua Riv., Camden Co., Mo.

Lampsilis mearnsi Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 75, pl. 1, fig. 4.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 564.
Simpson, 1914. Descr. Cat. Naiades: 150.
Type(s): LECTOTYPE [AS HOLOTYPE] USNM_151549 (by R.I. Johnson, 1975: 14), Elm Cr., 27 mi from Ft. Clark, Texas.

Lampsilis (Carunculina) texasensis var. compressus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 564.
Simpson, 1914. Descr. Cat. Naiades: 150.
(intro'd as intra-sp. of Unio texasiensis Lea, 1857)
Type(s): LECTOTYPE USNM_152059 (by R.I. Johnson, 1975: 11), Ft. Clark, Texas.

Lampsilis (Eurynia) higginsii var. grandis Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 78.
(intro'd as intra-sp. of Unio higginsii Lea, 1857)

Lampsilis (Eurynia) ligamentina var. nigrescens Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 82.
(intro'd as intra-sp. of Unio ligamentina Lamarck, 1819)
Type(s): LECTOTYPE USNM_150410 (by R.I. Johnson, 1975: 15), Kankakee R., Ill.

Lampsilis (Eurynia) subrostrata var. furva Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 100.
(intro'd as intra-sp. of Unio subrostratus Say, 1831)
Type(s): LECTOTYPE USNM_126921 (by R.I. Johnson, 1975: 13), Lake at Warsaw, Indiana.

Lampsilis (Proptera) lividus Simpson, 1900
‘Morelet’ Reeve, 1865. Conch. Icon. 16: pl. 22, sp. 101 [as ‘Unio testudineus’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 571.
Simpson, 1914. Descr. Cat. Naiades: 174.
Type(s): HOLOTYPE (MONOTYPY) BMNH_20190695 (by Cummings et al., 2025: 198), Rio Usumacinta, Guatemala.

Lampsilis (s.s.) binominatus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 528.
Simpson, 1914. Descr. Cat. Naiades: 42.
(new name for Unio lineatus Lea, 1840)

Lampsilis (s.s.) ventricosa var. lurida Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 41.
(intro'd as intra-sp. of Unio ventricosus Barnes, 1823)
Type(s): TYPE USNM_29958, Devil’s Lake, Lenawee Co., Mich.

Lampsilis (sec. Eurynia) ligamentina var. gibbus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 540.
Simpson, 1914. Descr. Cat. Naiades: 82.
(intro'd as intra-sp. of Unio ligamentina Lamarck, 1819)
Type(s): SYNTYPE USNM_160597, Black Rock, Arkansas.

Lanceolaria acrorhyncha Haas, 1911
‘von Martens’ of Authors.
Haas, 1911. Conch. Cab. 9 (pt. 2, h. 43): 61.
Simpson, 1914. Descr. Cat. Naiades: 956.
Haas, 1969. Das Tierreich 88: 67.
Kil, 1976. Korean J. Limnol. 9(3-4): 29.
Habe, 1977. Mollusc. Japan: 115.
Park & Kwon, 1993. Korean J. Malac. 9(1): 46.
Kondo, 2008. Spec. Publ. Malac. Soc. Japan (3): 27.
(error for Unio acrorrhynchus Martens, 1894)

Leguminaia nisibana Simpson, 1914
‘Kobelt’ Simpson, 1914. Descr. Cat. Naiades: 452.
(error for Leguminaia nisibina Kobelt, 1913)

Leguminaia (sec. Leguminaia) locardi Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 653.
Simpson, 1914. Descr. Cat. Naiades: 449.
(new name for Pseudodon chantrei Locard, 1883)

Margaritana curreyana Lea, 1842
‘Lea’ of Authors.
Lea, 1842. Trans. Amer. Phil. Soc. 8 [O. 3]: pl. 18, fig. 40.
Agassiz, 1852. Arch. Naturg. 18(1): 47.
Lea, 1852. Synopsis Fam. Naiades: 42.
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 263.
Adams & Adams, 1857. Gen. Rec. Moll. 2(31-32): 499.
Sowerby, 1868. Conch. Icon. 16: pl. 63, sp. 319.
Lea, 1870. Synopsis Fam. Naiades: 68.
B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [6].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 661.
Simpson, 1914. Descr. Cat. Naiades: 474.
Frierson, 1927. Check List N. Amer. Naiades: 21.
Haas, 1969. Das Tierreich 88: 395.
(error for Margaritana curreyiana Lea, 1840)

Margaritana etowahensis Simpson, 1900
‘Conrad’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 672.
Simpson, 1914. Descr. Cat. Naiades: 510.
Frierson, 1927. Check List N. Amer. Naiades: 19.
(error for Margaritana etowaensis Conrad, 1849)

Margaritana hembeli Simpson, 1900
‘Conrad’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 679.
Ortmann, 1912. Ann. Carnegie Mus. 8: 235, fig. 3.
Simpson, 1914. Descr. Cat. Naiades: 523. [in part]
Clench & Turner, 1956. Bull. Fla. State Mus. 1: 148, pl. 5, fig. 1.
(misidentified reference to Unio hembeli Conrad, 1838)

Margaritana vignoniana Paetel, 1890
‘Bernardi’ of Authors.
Paetel, 1890. Cat. Conch.-Samml. 3: 174.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 902.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 87.
Simpson, 1914. Descr. Cat. Naiades: 1347.
Modell, 1964. Arch. Moll. 93: 84.
(error for Margaritana vignouana Bernardi, 1859)

Monocondylaea tamsana Simpson, 1900
‘Dunker’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 913.
‘Dunker’ Simpson, 1914. Descr. Cat. Naiades: 1392.
(error for Monocondylaea tamsiana Dunker, 1858)

Mutela lavigerina Simpson, 1900
‘Bourguignat’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 906.
‘Bourguignat’ Simpson, 1914. Descr. Cat. Naiades: 1367.
(error for Mutela lavigeriana Bourguignat, 1886)

Nephronaias reticulatus Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 77, pl. 2, fig. 3.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 595.
Simpson, 1914. Descr. Cat. Naiades: 268.
Type(s): HOLOTYPE (MONOTYPY) USNM_152964, Patook [=Patuca] River, Capunta, Honduras.

Nodularia bohmi Simpson, 1900
‘Martens’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 823.
‘Martens’ Simpson, 1914. Descr. Cat. Naiades: 1036.
(error for Unio boehmi Martens, 1897)

Nodularia cylindrica Simpson, 1900
Schrenck, 1867. Reise Forsch. Amurlande 2: 694, pl. 27, figs. 1-3 [as ‘Unio grayanus Lea’].
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 84 [as ‘cylindracea’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 807.
Simpson, 1914. Descr. Cat. Naiades: 958.
(correct name for Nodularia cylindracea Simpson, 1900)

Nodularia (s.s.) fischeriania Simpson, 1900
‘Morlet’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 818.
‘Morlet’ Simpson, 1914. Descr. Cat. Naiades: 1009.
(error for Unio fischerianus Morlet, 1883)

Nodularia (sec. Cafferia) jickeli Simpson, 1900
‘Phil.’ Jickeli, 1874. Nova Acta Dtsch. Akad. Naturf. 37(1): 276, pl. 11, figs. 3-3b [as ‘U. teretiusculus’]. [in part]
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 826.
Simpson, 1914. Descr. Cat. Naiades: 579 [as ‘Unio jickeli’].

Nodularia (sec. Radiatula) lima Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 820.
Simpson, 1914. Descr. Cat. Naiades: 1018.
(new name for Unio radula Hanley, 1856)

Obovaria (s.s.) nux Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 297.
Type(s): HOLOTYPE USNM_152968, Tombigbee Riv., Moscow, Ala.

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

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.

Parreysia dumesleanus Simpson, 1900
‘Charmes’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 847.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 85.
Simpson, 1914. Descr. Cat. Naiades: 1130.
(error for Unio dumesnilianus Charmes, 1885)

Parreysia hypsiprimnus Simpson, 1900
‘von Martens’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 849.
Simpson, 1914. Descr. Cat. Naiades: 1136.
Haas, 1936. Abh. Senckenb. Naturf. Ges. 431: 68.
Woodward in Crowley et al., 1964. Annals Mus. R. Afr. Cent. 131: 47.
(error for Unio hypsiprymnus Martens, 1897)

Parreysia simpularis Simpson, 1900
‘Heude’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 845.
Simpson, 1914. Descr. Cat. Naiades: 1122.
Haas, 1924. Abh. Senckenb. Naturf. Ges. 38: 159.
Haas, 1969. Das Tierreich 88: 106.
He & Zhuang, 2013. Freshwater Bivalves China: 95.
(error for Unio simpularius Heude, 1884)

Physunio friersoni Simpson, 1914
‘Benson, in Hanley’ Sowerby, 1868. Conch. Icon. 16: pl. 72, sp. 368 [as ‘Unio velaris’].
Simpson, 1914. Descr. Cat. Naiades: 1068.
(new name for Unio velaris Sowerby, 1868)

Pleurobema avellana Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 81, pl. 2, figs. 6-7.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 758.
Simpson, 1914. Descr. Cat. Naiades: 778.
Type(s): HOLOTYPE UMMZ_79653, Cahaba River, Alabama.

Pleurobema patsaligensis Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 82, pl. 2, fig. 1.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 761.
Simpson, 1914. Descr. Cat. Naiades: 788.
Type(s): HOLOTYPE USNM_150475, Little Patsaliga Creek, Alabama.

Pleurobema argentea pannosa Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 82.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 763.
Simpson, 1914. Descr. Cat. Naiades: 799.
(intro'd as intra-sp. of Unio argenteus Lea, 1841)

Pleurobema brevis subelliptica Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 80.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 763 [as ‘subilliptica’].
Simpson, 1914. Descr. Cat. Naiades: 801.
(intro'd as intra-sp. of Unio brevis Lea, 1872)
Type(s): LECTOTYPE USNM_159952, Hardy, Ark.

Pleurobema fassinans var. rhomboidea Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 762.
Simpson, 1914. Descr. Cat. Naiades: 798.
(intro'd as intra-sp. of Unio fassinans Lea, 1868)
Type(s): LECTOTYPE USNM_133331 (by R.I. Johnson, 1975: 18), Clinch R., Va.

Pseudodon loomisi Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 84, pl. 4, fig. 7.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 840.
Simpson, 1914. Descr. Cat. Naiades: 1101.

Ptychobranchus clintonensis Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 79, pl. 5, fig. 3.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 613.
Simpson, 1914. Descr. Cat. Naiades: 335.
Type(s): HOLOTYPE USNM_124615, Little Red R., near Clinton, Ark.

Ptychobranchus trinacrium Simpson, 1914
‘Lea’ Simpson, 1914. Descr. Cat. Naiades: 337.
(error for Unio trinacrus Lea, 1861)

Ptychorhynchus pfisteri var. inspiratus Simpson, 1900
‘Heude’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 851.
‘Heude’ Simpson, 1914. Descr. Cat. Naiades: 1145.
(error for Unio pfisteri var. insperatus Heude, 1877)

Quadrula flexuosa Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 83, pl. 2, fig. 8.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 790.
Simpson, 1914. Descr. Cat. Naiades: 887.

Quadrula guatemalensis Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 83, pl. 2, fig. 4.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 796.
Simpson, 1914. Descr. Cat. Naiades: 909.
Type(s): HOLOTYPE (ORIG. DESIG.) USNM_128991, Usumacinta River, Guatemala.

Quadrula kirtlandiana Simpson, 1900
‘Conrad’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 791. [in part]
‘Conrad’ Simpson, 1914. Descr. Cat. Naiades: 891. [in part]
(misidentified reference to Unio kirtlandianus Lea, 1834)

Quadrula konangensis Simpson, 1914
‘Simpson, 1900’ Simpson, 1914. Descr. Cat. Naiades: 923.
(error for Quadrula (Lamprotula) kouangensis Simpson, 1900)

Quadrula lachrymosa Swainson, 1840
‘Lea’ of Authors.
Swainson, 1840. Treat. Malacol.: 378.
Hanley, 1843. Illustr. Descr. Cat. Rec. Bivalve Shells: 177.
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 256.
Adams & Adams, 1857. Gen. Rec. Moll. 2(31-32): 497.
Reeve, 1864. Conch. Icon. 16: pl. 9, sp. 33.
Call, 1895. Trans. Acad. Sci. St. Louis 7: 21.
F.C. Baker, 1898. Bull. Chicago Acad. Sci. 3(1): 83, pl. 25, fig. 1; pl. 12, fig. 2.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 776.
Call, 1900. Ind. Dept. Geol. Nat. Res. (1899): 489.
Ortmann, 1909. Nautilus 22(10): 100.
Ortmann, 1909. Ann. Carnegie Mus. 5: 199.
Ortmann, 1910. Nautilus 23(11): 140.
Ortmann, 1910. Nautilus 23: 116.
Ortmann, 1912. Ann. Carnegie Mus. 8: 253.
Simpson, 1914. Descr. Cat. Naiades: 839, 841.
Vanatta, 1915. Proc. Acad. Nat. Sci. 67: 556.
Ortmann & Walker, 1922. Occ. Pap. Mus. Zool. Univ. Mich. (112): 14, 16.
Frierson, 1927. Check List N. Amer. Naiades: 47.
F.C. Baker, 1928. Bull. Wisconsin Geol. Nat. Hist. Survey 70(2): 84.
R.I. Johnson, 1980. Bull. MCZ 149(2): 90.
Vidrine, 1993. Histr. Distr. Freshw. Mussels LA: 53.
Strayer & Jirka, 1997. Pearly Mussels NY (26): 98.
(error for Unio lacrymosus Lea, 1828)

Quadrula pyramidata Simpson, 1900
‘Lea’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 789. [in part]
Chadwick, 1906. unknown publication: 97.
‘Lea’ Simpson, 1914. Descr. Cat. Naiades: 889. [in part]
(reference to Unio pyramidatus Lea, 1831)

Quadrula rudis Simpson, 1900
Simpson, 1900. Proc. Acad. Nat. Sci. 52: 82, pl. 3, fig. 2.
Simpson, 1914. Descr. Cat. Naiades: 910.
Type(s): HOLOTYPE (MONOTYPY) USNM_84210, Rio Taxtunilha, (tributary to the Rio de la Pasion), Guatemala.

Quadrula (Discomya) radulosa var. rhomboidea Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 803.
Simpson, 1914. Descr. Cat. Naiades: 938.
(intro'd as intra-sp. of Unio radulosus Drouët & Chaper, 1892)
Type(s): HOLOTYPE (MONOTYPY) USNM_126472A, Sebroeang, Borneo.

Quadrula (Lamprotula) kouangensis Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 799, footnote.
Simpson, 1914. Descr. Cat. Naiades: 923 [as ‘konangensis’].
(new name for Unio moreletianus Heude, 1883)

Quadrula (Lamprotula) ovata Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 801.
Simpson, 1914. Descr. Cat. Naiades: 933.
(new name for Unio vestitus Heude, 1883)

Quadrula (Lamprotula) similaris Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 799.
Simpson, 1914. Descr. Cat. Naiades: 924.
(new name for Unio affinis Heude, 1875)

Quadrula (Rotundaria) profunda Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 907.
Type(s): HOLOTYPE (MONOTYPY) USNM_128987, Usumacinta River, Guatemala.

Quadrula (Rotundaria) quadrata Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 911.
Type(s): LECTOTYPE USNM_128996 (by R.I. Johnson, 1975: 18), Usumacinta River, Guatemala.

Quadrula (sec. Fusconaia) castanea Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 877.
Type(s): LECTOTYPE USNM_159959, Tombigbee R., Moscow, Ala.

Quadrula (sec. Fusconaia) wrightii Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 868.

Quadrula (sec. Fusconaia) chunii var. nasuta Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 877.
(intro'd as intra-sp. of Unio chunii Lea, 1861)

Quadrula (sec. Fusconaia) coccinea var. magnalacustris Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 884.
(new name for Quadrula (sec. Fusconaia) coccinea var. paupercula Simpson, 1900; intro'd as intra-sp. of Unio coccineus Conrad, 1836)
Type(s): LECTOTYPE USNM_133834, Niagara Riv., 3 mi above Falls.

Quadrula (sec. Fusconaia) kirtlandiana var. minor Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 791.
Simpson, 1914. Descr. Cat. Naiades: 892.
(intro'd as intra-sp. of Unio kirtlandianus Lea, 1834)
Type(s): LECTOTYPE USNM_150155, Scott Co., Va.

Quadrula (sec. Rotundaria) granifera var. pusilla Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 795.
Simpson, 1914. Descr. Cat. Naiades: 906.
(intro'd as intra-sp. of Unio graniferus Lea, 1838)
Type(s): LECTOTYPE MCZ_20176 (by R.I. Johnson, 1956: 131), Green River, Kentucky.

Rectidens prestoni Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 1159.
(new name for Unio perakensis Preston, 1912)

Shistodesmus spinosus Simpson, 1900
Heude, 1883. Conch. Fluv. Nanking (8): pl. 59, fig. 115 [as ‘Unio vestitus’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 804.
Simpson, 1914. Descr. Cat. Naiades: 941.

Spatha cailliaudi Martens, 1866
‘von Martens’ of Authors.
Martens, 1866. Malak. Blatt. 13: 102.
Lea, 1870. Synopsis Fam. Naiades: 89.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 896.
Pallary, 1909. Mém. Inst. Égypte 6(1): 83.
Simpson, 1914. Descr. Cat. Naiades: 1316.
(error for Spatha caillaudi Martens, 1866)
Type(s): SYNTYPES MNHN_MP_0196, Le Nil.

Spatha pangallicensis Simpson, 1900
‘Rochebrune’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 902.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 87.
Simpson, 1914. Descr. Cat. Naiades: 1350.
(error for Spatha pangallensis Rochebrune, 1882)

Spatha wissmani Simpson, 1900
‘von Martens’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 896.
‘von Martens’ Simpson, 1914. Descr. Cat. Naiades: 1315.
(error for Spatha wissmanni Martens, 1883)

Spatha (Moncetia) lavigerina Simpson, 1900
‘Bourguignat’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 901.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 87.
Simpson, 1914. Descr. Cat. Naiades: 1346.
(error for Moncetia lavigeriana Bourguignat, 1886)

Spatha (Moncetia) rochebruneana Simpson, 1900
‘Bourguignat’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 901.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 87.
Simpson, 1914. Descr. Cat. Naiades: 1346.
(error for Moncetia rochebruniana Bourguignat, 1886)

Spatha (s.s.) lacustris Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 898.
Simpson, 1914. Descr. Cat. Naiades: 1330.
(new name for Spatha anceyi Ancey, 1894)
Type(s): HOLOTYPE MRAC_57521, N. Nyassa, Karonga.

Trapezoideus peninsularis Simpson, 1900
‘Lea’ Reeve, 1865. Conch. Icon. 16: pl. 28, sp. 142 [as ‘Unio sumatrensis’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 859, footnote.
Simpson, 1914. Descr. Cat. Naiades: 1186.
Type(s): TYPE BMNH_1964159, Sumatra.

Tritogonia tuberculata var. obesa Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 609.
Simpson, 1914. Descr. Cat. Naiades: 320.
(intro'd as intra-sp. of Unio tuberculatus Barnes, 1823)
Type(s): LECTOTYPE USNM_125669 (by R.I. Johnson, 1975: 16), Neches River, Big Eddy, Texas.

Truncilla (Scalenaria) sulcata var. delicata Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 520, footnote.
Simpson, 1914. Descr. Cat. Naiades: 16.
(intro'd as intra-sp. of Unio sulcatus Lea, 1829)
Type(s): SYNTYPE USNM_160853, Amherstburg, Michigan.

Unio aethiopiformis Simpson, 1900
‘von Ihering’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 894. [nomen nudum]
‘von Ihering’ Simpson, 1914. Descr. Cat. Naiades: 1312. [nomen nudum]
Type(s): NOMEN NUDUM MCZ_192369, Rio Camaquam, Rio Grande do Sul, Brazil.

Unio averillii Simpson, 1900
“Wright” of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 560.
Simpson, 1914. Descr. Cat. Naiades: 138.
Frierson, 1927. Check List N. Amer. Naiades: 76.
R.I. Johnson, 1970. Bull. MCZ 140(6): 373.
R.I. Johnson, 1972. Bull. Fla. State Mus. 16(4): 237.
Burch, 1975. Freshw. Unio. North Amer.: 159.
(error for Unio averellii B.H. Wright, 1888)

Unio barrandii Simpson, 1900
‘Dupuy’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 692.
‘Dupuy’ Simpson, 1914. Descr. Cat. Naiades: 555.
(error for Unio barraudii Bonhomme, 1840)

Unio billotianus Simpson, 1900
‘Charmes’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 847.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 84.
Simpson, 1914. Descr. Cat. Naiades: 1130.
Haas, 1936. Abh. Senckenb. Naturf. Ges. 431: 52.
Haas, 1969. Das Tierreich 88: 190.
Daget, 1998. Cat. Bivalves Africains: 65.
(error for Unio billottianus Charmes, 1885)

Unio bischoffi Simpson, 1914
‘von Ihering’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 894 [as ‘bishoffi’]. [nomen nudum]
‘von Ihering’ Simpson, 1914. Descr. Cat. Naiades: 1312. [nomen nudum]

Unio bissellianus Lea, 1870
‘Lea’ of Authors.
Lea, 1870. Synopsis Fam. Naiades: 50.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 743.
Simpson, 1914. Descr. Cat. Naiades: 714.
Frierson, 1927. Check List N. Amer. Naiades: 35.
Haas, 1969. Das Tierreich 88: 210.
(error for Unio bisselianus Lea, 1867)

Unio bythinicus Simpson, 1900
‘Kobelt’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 695.
Simpson, 1914. Descr. Cat. Naiades: 565.
Haas, 1940. Zool. Ser. Field Mus. Nat. Hist. 24: 141.
(error for Unio bithynicus Kobelt, 1893)

Unio cistelliformis Simpson, 1900
‘Lea’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 716.
Simpson, 1914. Descr. Cat. Naiades: 641.
Frierson, 1927. Check List N. Amer. Naiades: 29.
Haas, 1969. Das Tierreich 88: 228.
R.I. Johnson, 1970. Bull. MCZ 140(6): 317.
Davis et al., 1981. Biol. J. Linn. Soc. 15: 135.
Davis, 1984. Malacologia 25(2): 631.
Williams et al., 1993. Fisheries 18(9): 11.
Haag, 2012. N. Amer. Freshw. Mussels: 73.
(error for Unio cistellaeformis Lea, 1863)

Unio crocodilarum Simpson, 1900
‘Morelet’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 702.
Simpson, 1914. Descr. Cat. Naiades: 591.
Haas, 1929. Senckenbergiana 11: 332.
(error for Unio crocodilorum Morelet, 1849)

Unio daniellii Simpson, 1900
‘Villa’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 891.
Simpson, 1914. Descr. Cat. Naiades: 1298.
(error for Unio danellii Villa, 1871)

Unio diarbekerianus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 732.
(error for Unio diarbekirianus Kobelt, 1913)

Unio dorbignyanus Simpson, 1900
‘Sowerby’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 866 [as ‘d’orbignyanus’].
‘Sowerby’ Simpson, 1914. Descr. Cat. Naiades: 1208 [as ‘d’orbignyanus’].
(error for Unio dorbignianus Sowerby, 1868)

Unio faidherbi Simpson, 1900
‘Jousseaume’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 822.
Kobelt, 1910. Abh. Senckenb. Naturf. Ges. 32: 84.
Simpson, 1914. Descr. Cat. Naiades: 1027.
(error for Reneus faidherbei Jousseaume, 1886)

Unio flexicosus Simpson, 1914
‘Neumayr’ Simpson, 1914. Descr. Cat. Naiades: 721.
(error for Unio flexuosus Neumayr, 1899)

Unio forscali Simpson, 1900
‘Parreyss’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 862. [nomen nudum]
‘Parreyss’ Simpson, 1914. Descr. Cat. Naiades: 1192. [nomen nudum]

Unio granadensis Simpson, 1900
‘Conrad’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 598.
Simpson, 1914. Descr. Cat. Naiades: 289 [corrected in corrigenda].
Morrison, 1943. Nautilus 57: 15.
(error for Unio grandensis Conrad, 1855)

Unio guahybae Simpson, 1900
‘von Ihering’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 894. [nomen nudum]
‘von Ihering’ Simpson, 1914. Descr. Cat. Naiades: 1312. [nomen nudum]
Type(s): NOMEN NUDUM SMF_168335, Guahyba, Rio Grande do Sul, Brasil.

Unio hanleyanus Conrad, 1853
‘Lea’ of Authors.
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 250.
Sowerby, 1866. Conch. Icon. 16: pl. 46, sp. 249.
B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [3].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 759.
Simpson, 1914. Descr. Cat. Naiades: 780.
Frierson, 1927. Check List N. Amer. Naiades: 42, sp. 175.
Haas, 1969. Das Tierreich 88: 256.
Burch, 1975. Freshw. Unio. North Amer.: 13.
Turgeon et al., 1988. Am. Fisher. Soc. Spec. Publ. (16): 32.
Williams et al., 1993. Fisheries 18(9): 13.
Parmalee & Bogan, 1998. The Freshwater Mussels of Tennessee: 184.
Lydeard et al., 1999. Gulf Mex. Sci. 17(2): 129.
(error for Unio hanleyianus Lea, 1852)

Unio hazelhurstianus B.H. Wright, 1888
‘Lea’ of Authors.
B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [3].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 719 [as ‘Unio (sec. Elliptio) hazelhurstianus’].
Simpson, 1914. Descr. Cat. Naiades: 648.
Frierson, 1927. Check List N. Amer. Naiades: 29 [as ‘Elliptio (Elliptio) hazelhurstianus’].
Haas, 1969. Das Tierreich 88: 229 [as ‘Elliptio (Elliptio) hazelhurstianus’].
R.I. Johnson, 1970. Bull. MCZ 140(6): 333.
Burch, 1975. Freshw. Unio. North Amer.: 164.
(error for Unio hazlehurstianus Lea, 1858)

Unio hippopaeus Lea, 1852
‘Lea’ of Authors.
Lea, 1852. Synopsis Fam. Naiades: 21 [as ‘hippopæus’].
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 261 [as ‘hippopæus’].
Adams & Adams, 1857. Gen. Rec. Moll. 2(31-32): 497 [as ‘hippopæus’].
Reeve, 1864. Conch. Icon. 16: pl. 11, sp. 40 [as ‘hippopæus’].
Lea, 1870. Synopsis Fam. Naiades: 31 [as ‘hippopæus’].
B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [3], [as ‘hippopæus’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 767 [as ‘hippopæa’].
Ortmann, 1909. Nautilus 22(10): 101 [as ‘Q. hippopæa’].
Ortmann, 1909. Ann. Carnegie Mus. 5: 203 [as ‘Quadrula undulata hippopæa’].
Simpson, 1914. Descr. Cat. Naiades: 816 [as ‘hippopæa’].
Frierson, 1927. Check List N. Amer. Naiades: 61.
Haas, 1969. Das Tierreich 88: 287.
Clarke, 1973. Malacologia 13(1-2): 35.
Burch, 1975. Freshw. Unio. North Amer.: 165.
Strayer & Jirka, 1997. Pearly Mussels NY (26): 98.
He & Zhuang, 2013. Freshwater Bivalves China: 27.
(error for Unio hippopoeus Lea, 1845)

Unio houngdaranicus Simpson, 1900
‘Tapparone Canefri’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 844.
Preston, 1912. Rec. Ind. Mus. 7: 301.
Simpson, 1914. Descr. Cat. Naiades: 1116.
Preston, 1915. Fauna Brit. India: 167.
Prashad, 1922. Rec. Ind. Mus. 24: 101.
Subba Rao, 1989. Freshw. Moll. India: 183.
Graf & Cummings, 2007. J. Moll. Studies 73: 311.
Bogan, 2010. FADA: [25].
(error for Unio houngdarauicus Tapparone Canefri, 1889)

Unio idgi Simpson, 1900
‘Bourguignat’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 862.
‘Bourguignat’ Simpson, 1914. Descr. Cat. Naiades: 1193.
(error for Unio ilqi Bourguignat, 1885)

Unio ilqui Simpson, 1900
‘Soleilet’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 862.
‘Soleillet’ Simpson, 1914. Descr. Cat. Naiades: 1193.
(error for Unio ilqi Bourguignat, 1885)

Unio koseretzi Simpson, 1900
‘Clessin’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 894.
Simpson, 1914. Descr. Cat. Naiades: 1312.
Haas, 1930. Senckenbergiana 12: 182.
Bonetto, 1964. Physis 24(68): 327.
Parodiz, 1968. Sterkiana 30: 7.
Bonetto & Mansur, 1970. Acta Zool. Lilloana 27: 245.
(error for Unio koseritzi Clessin, 1888)

Unio lawleyanus Kobelt, 1884
‘Gentiluomo’ of Authors.
Kobelt, 1884. Icon. Land- und Süssw.-Moll. 1: 65.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 683.
Simpson, 1914. Descr. Cat. Naiades: 533.
Haas, 1940. Zool. Ser. Field Mus. Nat. Hist. 24: 127.
(error for Unio lawleyianus Gentiluomo, 1868)

Unio longitudinatus Simpson, 1900
‘Anton’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 862.
‘Anton’ Simpson, 1914. Descr. Cat. Naiades: 1193.
(error for Unio (s.s.) longedentatus Anton, 1839)

Unio mitchelli Dall, 1895
Simpson in Dall, 1895. Proc. U.S. Nat. Mus. 18: 5.
Simpson, 1896. Proc. U.S. Nat. Mus. 18: 371, pl. 32, figs. 1-3.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 711.
Simpson, 1914. Descr. Cat. Naiades: 622.
Type(s): LECTOTYPE [AS HOLOTYPE] USNM_128364 (by R.I. Johnson, 1975: 15), Guadalupe R., Victoria Co., Texas.

Unio nasululus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 691.
(error for Unio nasutulus Lea, 1866)

Unio nasutilus Simpson, 1900
‘Lea’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 735.
Simpson, 1914. Descr. Cat. Naiades: 691.
R.I. Johnson, 1970. Bull. MCZ 140(6): 334.
Burch, 1975. Freshw. Unio. North Amer.: 167.
Bogan, 2002. Workbook Key Freshw. Biv. NC: Table 5.
Perkins et al., 2017. Conserv. Genet. 18: 752.
Inoue et al., 2018. Invert. Syst. 32: Table S2.
(error for Unio nasutidus Lea, 1863)

Unio navigoliformis Simpson, 1900
‘Lea’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 825.
‘Lea’ Simpson, 1914. Descr. Cat. Naiades: 575.
(error for Unio navigioliformis Lea, 1859)

Unio panucoensis Martens, 1900
‘von dem Busch’ of Authors.
Martens, 1900. Biol. Centr.-Amer., Moll.: 510, 651.
Pilsbry, 1910. Proc. Acad. Nat. Sci. 61: 533.
Simpson, 1914. Descr. Cat. Naiades: 603.
Frierson, 1927. Check List N. Amer. Naiades: 82.
(error for Unio panacoensis Philippi, 1843)

Unio penisatus Simpson, 1900
‘Crosse & Fischer’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 853.
Haas, 1912. Conch. Cab. 9 (pt. 2, h. 46): 135.
Simpson, 1914. Descr. Cat. Naiades: 1155.
(error for Unio pensitatus Fischer & Crosse, 1894)

Unio pequottianus Simpson, 1900
‘Linsley’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 744.
‘Linsley’ Simpson, 1914. Descr. Cat. Naiades: 731.
(error for Unio pequottinus Linsley, 1845)

Unio phayresi Simpson, 1900
‘Theobald’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 842.
Simpson, 1914. Descr. Cat. Naiades: 1107.
Preston, 1915. Fauna Brit. India: 155.
(intro'd as syn of Mya corrugata Müller, 1774)

Unio planilaterus Lea, 1852
‘Conrad’ of Authors.
Lea, 1852. Synopsis Fam. Naiades: 32.
Lea, 1870. Synopsis Fam. Naiades: 51.
B.H. Wright, 1888. Check List N. Amer. Unionidae etc.: [4].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 722.
Simpson, 1914. Descr. Cat. Naiades: 653.
(error for Unio planilateris Conrad, 1838)

Unio platiolus Simpson, 1900
‘Rafinesque’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 744.
‘Rafinesque’ Simpson, 1914. Descr. Cat. Naiades: 731.
(error for Obliquaria plateolus Rafinesque, 1831)

Unio popeii Fischer & Crosse, 1894
of Authors.
Fischer & Crosse, 1894. Miss. Sci. Mexique, Rech. Zool. 2(16): 605 [as ‘Unio (Graphonaias) popei’].
Martens, 1900. Biol. Centr.-Amer., Moll.: 504 [as ‘Unio (Nephronaias) popei’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 738 [as ‘Unio (sec. Elliptio)’]. [in part]
Pilsbry, 1910. Proc. Acad. Nat. Sci. 61: 535. [in part]
Ortmann, 1912. Ann. Carnegie Mus. 8: 271 [as ‘Elliptio’].
Simpson, 1914. Descr. Cat. Naiades: 700 [as ‘Unio (sec. Elliptio)’]. [in part]
Frierson, 1927. Check List N. Amer. Naiades: 38 [as ‘Elliptio (Popenaias)’]. [in part]
Haas, 1929. Senckenbergiana 11: 330 [as ‘Elliptio (Popenaias)’]. [in part]
Haas, 1969. Das Tierreich 88: 201 [as ‘Nephronaias (Popenaias)’]. [in part]
Graf & Cummings, 2007. J. Moll. Studies 73: 308 [as ‘Popenaias’]. [in part]
Pfeiffer et al., 2019. Zool. Scripta 48: 504 [as ‘Popenaias’]. [in part]
(misidentified reference to Unio popeii Lea, 1857)

Unio pygamaeus Simpson, 1914
‘Lea’ Simpson, 1914. Descr. Cat. Naiades: 649.
(error for Unio pygmaeus Lea, 1852)

Unio reevianus Conrad, 1853
‘Lea’ of Authors.
Conrad, 1853. Proc. Acad. Nat. Sci. 6: 256.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 538.
Simpson, 1914. Descr. Cat. Naiades: 74.
Utterback, 1916. Amer. Midl. Nat. 4(10): 449.
Frierson, 1927. Check List N. Amer. Naiades: 73.
Haas, 1969. Das Tierreich 88: 437.
R.I. Johnson, 1980. Bull. MCZ 149(2): 132.
Oesch, 1984. Missouri Naiades: 225.
Turgeon et al., 1988. Am. Fisher. Soc. Spec. Publ. (16): 31.
Williams et al., 1993. Fisheries 18(9): 12.
Turgeon et al., 1998. Am. Fisher. Soc. Spec. Publ. (26): 35.
Graf & Cummings, 2007. J. Moll. Studies 73: 305.
Bogan, 2010. FADA: [web].
Cummings & Graf, 2010. Ecol. Class. N. Amer. FW Inverts.: 376.
Haag, 2012. N. Amer. Freshw. Mussels: 71 [as ‘Lampsilis reeviana’].
(error for Unio reeveianus Lea, 1852)

Unio sacellus Simpson, 1900
‘Drouet & Chaper’ of Authors.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 818.
Simpson, 1914. Descr. Cat. Naiades: 1011.
Haas, 1924. Abh. Senckenb. Naturf. Ges. 38: 198.
(error for Unio saccellus Drouët & Chaper, 1892)

Unio sancta-paulae Simpson, 1914
‘von Ihering’ Simpson, 1914. Descr. Cat. Naiades: 1312. [nomen nudum]

Unio sebastanae Simpson, 1900
‘von Ihering’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 894. [nomen nudum]
‘von Ihering’ Simpson, 1914. Descr. Cat. Naiades: 1312. [nomen nudum]

Unio sowerbyanus Küster, 1852
‘Lea’ of Authors.
Küster, 1852. Conchyl. Cab. 9(2): 62.
Agassiz, 1852. Arch. Naturg. 18(1): 43.
Reeve, 1864. Conch. Icon. 16: pl. 14, sp. 58.
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 520.
Simpson, 1914. Descr. Cat. Naiades: 17.
Frierson, 1927. Check List N. Amer. Naiades: 94.
Haas, 1969. Das Tierreich 88: 483.
Burch, 1975. Freshw. Unio. North Amer.: 173.
R.I. Johnson, 1978. Bull. MCZ 148: 280.
Parmalee & Bogan, 1998. The Freshwater Mussels of Tennessee: 91.
(error for Unio sowerbianus Lea, 1834)

Unio sula Simpson, 1900
‘Theobald’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 678.
‘Theobald’ Simpson, 1914. Descr. Cat. Naiades: 521.
(intro'd as syn of Unio laosensis Lea, 1863)

Unio tahetianus Simpson, 1900
‘Catlow & Reeve’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 744.
‘Catlow & Reeve’ Simpson, 1914. Descr. Cat. Naiades: 731.
(error for Unio tahitianus Catlow & Reeve, 1845)

Unio taniatus Simpson, 1900
‘Paetel’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 541.
‘Paetel’ Simpson, 1914. Descr. Cat. Naiades: 83.
(error for Unio taeniatus Conrad, 1834)

Unio valentinus Simpson, 1900
‘Sowerby’ Simpson, 1900. Proc. U.S. Nat. Mus. 22: 692.
‘Sowerby’ Simpson, 1914. Descr. Cat. Naiades: 555.
(error for Unio valentianus Sowerby, 1866)

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)

Unio (Micronaias) fallaciosus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 715.
Type(s): LECTOTYPE [AS HOLOTYPE] USNM_1673591 (by Cummings et al., 2025: 217), Lake Nicaragua, Nicaragua.

Unio (sec. Elliptio) gibbosus var. delicatus Simpson, 1900
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 704.
Simpson, 1914. Descr. Cat. Naiades: 600.
(homonym of Unio delicatus Lea, 1863; intro'd as intra-sp. of Unio gibbosus Barnes, 1823)
Type(s): LECTOTYPE USNM_128797, St. Francis R., Greenway, Clay Co., Arkansas.

Unio (sec. Elliptio) mitchelli var. elongatus Simpson, 1914
Simpson, 1914. Descr. Cat. Naiades: 623.
(homonym of Unio elongata Lamarck, 1819; intro'd as intra-sp. of Unio mitchelli Dall, 1895)
Type(s): LECTOTYPE USNM_251917 (by R.I. Johnson, 1975: 12), Guadalupe River, near Kerrville, Texas.

Unio (sec. Lymnium) pseudonymus Simpson, 1900
‘Bourg.’ Kobelt, 1886. Icon. Land- und Süssw.-Moll. 2: 22, pl. 41, fig. 255 [as ‘U. hueti’].
Simpson, 1900. Proc. U.S. Nat. Mus. 22: 694.
Simpson, 1914. Descr. Cat. Naiades: 560.

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)