Unio elongatula C. Pfeiffer, 1825
C. Pfeiffer, 1825. Natur. Deutsch. Land Sussw. Moll. 2: 35, pl. 8, figs. 5-6.
Type(s): NEOTYPE MZUF_BC_53138, Vipava (Vipacco) River, Savogna d’Isonzo, Gorizia, Friuli-Venezia Giulia, Italy.

Unio (sec. Lymnium) elongatulus — Simpson (1900), Simpson (1914)
Unio (Groupe des Elongatulusiana) elongatulus — Caziot (1907)
Unio elongatulus elongatulus — Haas (1940), Haas (1969), Fauna Europaea (2012)
Unio elongatus [sic] — Haas (1952)
Unio elongatulus — Van Damme (1984), Mandahl-Barth (1988), Dhora (2009), Bogan (2010), Prie et al. (2012), ... Wu et al. (2024), Wu et al. (2024), Dai et al. (2024), Hou et al. (2024), Dai et al. (2025)
Unio mancus — Nagel et al. (1998), Araujo et al. (2005), Graf & Cummings (2007), Graf & Cummings (2011), IUCN (2014)
Unio cf. elongatulus — Lopes-Lima et al. (2017)

Unio elongatus Lea, 1836
‘Pfeiffer’ of Authors.
Lea, 1836. Synopsis Fam. Naiades: 37.
Lea, 1838. Synopsis Fam. Naiades: 24.
Lea, 1852. Synopsis Fam. Naiades: 37.
Adams & Adams, 1857. Gen. Rec. Moll. 2(31-32): 491.
Haas, 1952. Nautilus 65(4): 118.
Bogan, 1993. Amer. Zool. 33: 602.
(error for Unio elongatula C. Pfeiffer, 1825)

Unio glaucinus Porro, 1838
Porro, 1838. Malacol. Prov. Comasca: 115.

Unio (sec. Lymnium) batavus — Simpson (1900), Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969), Fauna Europaea (2012)
Unio (s.s.) mancus glaucinus — Falkner et al. (2001)
Unio mancus — Araujo et al. (2005), IUCN (2014), Araujo et al. (2018)
Unio cf. elongatulus — Lopes-Lima et al. (2017)
Unio elongatulus — Marrone et al. (2019)

Potomida sicula Swainson, 1840
Swainson, 1840. Treat. Malacol.: 282, fig. 58.
Type(s): POSSIBLE SYNTYPE BMNH_1907-10-28-255, Lake Leontini, Sicily.

Unio (sec. Lymnium) pictorum — Simpson (1900), Simpson (1914)
Unio pictorum — He & Zhuang (2013)

Unio corrosus Villa, 1841
Villa, 1841. Dispos. Syst. Conchyl.: 61.

Unio crassus — Germain (1931)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio pallens Rossmässler, 1842
‘Parr.’ Rossmässler, 1842. Icon. Land- und Süssw.-Moll. 2 (5): 13, pl. 54, fig. 740.

Unio (sec. Lymnium) turtoni — Simpson (1900), Simpson (1914)
Unio elongatulus pallens — Haas (1940), Haas (1969), Fauna Europaea (2012)
Unio mancus pallens — Lopes-Lima et al. (2017)
Unio elongatulus — Araujo et al. (2018), Marrone et al. (2019)

Unio sandrii Rossmässler, 1844
‘Villa’ Rossmässler, 1844. Icon. Land- und Süssw.-Moll. 2 (6): 26, pl. 56, fig. 748-749.

Unio (sec. Lymnium) batavus — Simpson (1900), Simpson (1914)
Unio elongatulus sandrii — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio sandrii var. sericatus Rossmässler, 1844
‘Parreyss’ Rossmässler, 1844. Icon. Land- und Süssw.-Moll. 2 (6): 27, pl. 56, fig. 750.
(intro'd as intra-sp. of Unio sandrii Rossmässler, 1844)

Unio elongatulus sandrii — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio pictorum var. parva Stabile, 1845
Stabile, 1845. Faun. Lug.: 61, f. 73.
(homonym of Unio parvus Barnes, 1823; renamed Unio eucallistellus Bourguignat, 1883)

Unio elongatulus — Marrone et al. (2019)

Unio spinellii Spinelli, 1851
‘Villa’ Spinelli, 1851. Cat. Moll. Terr. Fluv. Prov. Brescia: 20, figs. 7-8.

Unio (sec. Lymnium) batavus — Simpson (1900), Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio petrovichii Küster, 1854
Küster, 1854. Conchyl. Cab. 9(2): 98, pl. 26, figs. 5-6; pl. 27, fig. 1.

Unio (sec. Lymnium) pictorum — Simpson (1900), Simpson (1914)
Unio elongatulus pallens — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio petterianus Küster, 1854
Küster, 1854. Conchyl. Cab. 9(2): 97, pl. 26, fig. 4.

Unio (sec. Lymnium) batavus — Simpson (1900), Simpson (1914)
Unio elongatulus pallens — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio viridiflavus Küster, 1854
Küster, 1854. Conchyl. Cab. 9(2): 96, pl. 26, figs. 2-3.

Unio (sec. Lymnium) pictorum — Simpson (1900), Simpson (1914)
Unio elongatulus pallens — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio requienii var. blauneri Stabile, 1859
‘Shuttleworth’ Stabile, 1859. Atti soc. geol. Milano 1: 170, 185, sp. 51.
(intro'd as intra-sp. of Unio requienii Michaud, 1831)

— Simpson (1914)
Unio blauneri — Haas (1924)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio requienii var. oriliensis Stabile, 1859
Stabile, 1859. Atti soc. geol. Milano 1: 170, 184, sp. 50.
(intro'd as intra-sp. of Unio requienii Michaud, 1831)

— Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio requienii var. vulgaris Stabile, 1859
Stabile, 1859. Atti soc. geol. Milano 1: 170, 184, sp. 49.
(intro'd as intra-sp. of Unio requienii Michaud, 1831)

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio villae Issel, 1872
Issel, 1872. Mem. Soc. Ital. Sci. Nat. 2: 35.

Unio villæ — Rochebrune (1903)
Unio villae — Germain (1931)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)

Unio fiscallianus Kobelt, 1873
Kleciach in Kobelt, 1873. Malak. Blatt. 20: 92, text fig.

Unio (sec. Lymnium) platyrhynchus — Simpson (1900), Simpson (1914)
Unio elongatulus fiscallianus — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio ceratinus Drouët, 1879
Drouët, 1879. J. de Conch. 27: 328.

Unio elongatulus sandrii — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio dalmaticus Drouët, 1879
Drouët, 1879. J. de Conch. 27: 141.

Unio elongatulus sandrii — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio kleciaki Drouët, 1879
Drouët, 1879. J. de Conch. 27: 328.

— Simpson (1900), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio kruperi Drouët, 1879
Kob. fig. 1644-1645 of Authors.
Drouët, 1879. J. de Conch. 27: 140.

Unio elongatulus kruperi — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio (s.s.) mancus kruperi — Falkner (1994), Bank (2006)

Unio nitidosus Drouët, 1879
Drouët, 1879. J. de Conch. 27: 140.

Unio elongatulus pallens — Haas (1940), Haas (1969)
Unio (s.s.) mancus kruperi — Bank (2006)

Unio robustus Drouët, 1879
‘Villa, in sched.’ Drouët, 1879. J. de Conch. 27: 141.
(homonym of Unio robustus Sowerby, 1840; renamed Unio larius Drouët, 1883)

Unio elongatulus glaucinus — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio brachyrhynchus Drouët, 1881
Drouët, 1881. J. de Conch. 29: 246.

— Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio decipiens Drouët, 1881
Drouët, 1881. J. de Conch. 29: 23.

Unio elongatulus decipiens — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio succineus Drouët, 1881
Drouët, 1881. J. de Conch. 29: 245.

Unio elongatulus sandrii — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio opisodartos Adami, 1882
Adami, 1882. Boll. Soc. Malac. Ital. 8: 134, pl. 0, figs. 9-10.

— Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio stephaninii Adami, 1882
Adami, 1882. Boll. Soc. Malac. Ital. 8: 129, pl. 0, figs. 1-2.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio veillanensis Locard, 1882
‘H. Blanc’ Locard, 1882. Prodr. Malac. Franç. 1: 292, 361.
‘H. Blanc’ Locard, 1889. Contr. Faune Malacol. Franc. 13: 154 [48].
‘H. Blanc’ Locard, 1893. Coqu. Eau Douce Saumâtre France: 185.
Type(s): LECTOTYPE MNHN_22601 (by Graf, 2011: 511), Montpellier.

Unio villae — Germain (1931)
Unio elongatulus requienii — Haas (1940), Haas (1969)
Unio mancus requienii — Prie (2012)

Unio benacinus Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 74.

— Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio brianteus Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 35.

— Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio callichrous Bourguignat, 1883
Letourneux in Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 49.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)

Unio delpretei Bourguignat, 1883
Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 23.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio eucallistellus Bourguignat, 1883
Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 48.
(new name for Unio pictorum var. parva Stabile, 1845)

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio fluminalis Drouët, 1883
Kobelt, 1876. Icon. Land- und Süssw.-Moll. 4: 63, pl. 117, fig. 1148 [as ‘U. requieni’].
Drouët, 1883. Unionidae de l’Italie: 35.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio gredleri Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 68.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio gurkensis Bourguignat, 1883
Ziegler in Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 21.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio idrinus Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 42.

Unio elongatulus — Marrone et al. (2019)

Unio larius Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 26.
(new name for Unio robustus Drouët, 1879)

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio longobardus Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 54.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio minusculus Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 77.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio nitidus Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 57.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio padanus Bourguignat, 1883
H. Blanc in Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 57.

Unio requieni — Germain (1931)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio mancus requienii — Prie (2012)
Unio elongatulus — Marrone et al. (2019)

Unio pedemontanus Bourguignat, 1883
Kobelt, 1876. Icon. Land- und Süssw.-Moll. 4: 63, pl. 117, fig. 1148 [as ‘U. requienii].
Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 60.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)

Unio sebinensis Bourguignat, 1883
Uzielli in Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 13.

— Simpson (1914)
Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio siliquatus Drouët, 1883
Drouët, 1883. Unionidae de l’Italie: 66.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio strobeli Bourguignat, 1883
Uzielli in Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 58.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio subcylindricus Drouët, 1883
‘Pini, in sched.’ Drouët, 1883. Unionidae de l’Italie: 34.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio verbanicus Bourguignat, 1883
Letourneux in Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 18.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio cusianus Pini, 1884
Pini, 1884. Atti Soc. Ital. Sci. Nat. 27: 82, text fig.

Unio elongatulus glaucinus — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio rusticus Pini, 1884
Pini, 1884. Atti Soc. Ital. Sci. Nat. 27: 80, text figs.
(homonym of Unio rusticus Lea, 1856)

— Simpson (1900), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio athesinus Adami, 1886
Adami, 1886. Boll. Soc. Malac. Ital. 11: 236, figs. 16-17.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio bourguignatianus Adami, 1886
Adami, 1886. Boll. Soc. Malac. Ital. 11: 234, figs. 13-14.
(homonym of Unio bourguignatianus Lea, 1863; renamed Unio magistri Westerlund, 1890)

— Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio cristophori Adami, 1886
Adami, 1886. Boll. Soc. Malac. Ital. 11: 242, figs. 24-25.

— Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio gredleri Adami, 1886
Adami, 1886. Boll. Soc. Malac. Ital. 11: 245, fig. 22.
(homonym of Unio gredleri Drouët, 1883; renamed Unio humerosus Westerlund, 1890)

Unio piccinellii Adami, 1886
Adami, 1886. Boll. Soc. Malac. Ital. 11: 239, figs. 18-19.

— Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio ruffonii Adami, 1886
Adami, 1886. Boll. Soc. Malac. Ital. 11: 248, figs. 26-27.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio tommasii Adami, 1886
Adami, 1886. Boll. Soc. Malac. Ital. 11: 241, figs. 20-21.

— Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio christophori Servain, 1888
‘Adam’ of Authors.
Servain, 1888. Bull. Soc. Malac. France 5: 319.
Westerlund, 1890. Fauna Paläarct. Binnenconch. 2(7): 168.
(error for Unio cristophori Adami, 1886)

Unio humerosus Westerlund, 1890
Westerlund, 1890. Fauna Paläarct. Binnenconch. 2(7): 136.
(homonym of Unio humerosus Lea, 1868; new name for Unio gredleri Adami, 1886)

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio lijacensis Kobelt, 1890
Kobelt, 1890. Icon. Land- und Süssw.-Moll. 4: 94, pl. 117, figs. 706, 708.

Unio elongatulus elongatulus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio magistri Westerlund, 1890
Westerlund, 1890. Fauna Paläarct. Binnenconch. 2(7): 132.
(new name for Unio bourguignatianus Adami, 1886)

Unio lijacensis var. gallensteini Kobelt, 1890
Kobelt, 1890. Icon. Land- und Süssw.-Moll. 4: 94, pl. 117, fig. 707.
(intro'd as intra-sp. of Unio lijacensis Kobelt, 1890)
Type(s): TYPE SMF_4353, Gösselsdorfer See, Kärnten [Austria].

Unio elongatulus elongatulus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio veilanensis Locard, 1893
‘Blanc’ of Authors.
Locard, 1893. Coqu. Eau Douce Saumâtre France: 185.
Germain, 1931. Faune de France 22: 735.
(error for Unio veillanensis Locard, 1882)

Unio athesinus var. trilacensis Gredler, 1894
Gredler, 1894. Slebstvelag der Lehranstalt 8: ??.
(intro'd as intra-sp. of Unio athesinus Adami, 1886)

Unio elongatulus — Marrone et al. (2019)

Unio humerosus var. monticellensis Gredler, 1894
Gredler, 1894. Slebstvelag der Lehranstalt 8: ??.
(intro'd as intra-sp. of Unio humerosus Westerlund, 1890)

Unio elongatulus — Marrone et al. (2019)

Unio limosus var. arcensis Gredler, 1894
Gredler, 1894. Slebstvelag der Lehranstalt 8: ??.
(intro'd as intra-sp. of Unio limosus Nilsson, 1822)

Unio elongatulus — Marrone et al. (2019)

Unio limosus var. costanus Gredler, 1894
Tiesenhausen in Gredler, 1894. Slebstvelag der Lehranstalt 8: 35.
(intro'd as intra-sp. of Unio limosus Nilsson, 1822)

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio copaisanus Drouët, 1895
‘Clessin, in sched.’ Drouët, 1895. J. de Conch. 43: 27, sp. 102.

Unio elongatulus quelleneci [sic] — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio (s.s.) mancus kruperi — Bank (2006)

Unio directus Drouët, 1895
Drouët, 1895. J. de Conch. 43: 30, sp. 106.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio palustris Drouët, 1895
Drouët, 1895. J. de Conch. 43: 31, sp. 107.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio quellenneci Drouët, 1895
Drouët, 1895. J. de Conch. 43: 26, sp. 101.

Unio elongatulus quelleneci [sic] — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio (s.s.) mancus kruperi — Bank (2006)

Unio segregatus Drouët, 1895
‘Monterosato, in sched.’ Drouët, 1895. J. de Conch. 43: 29, sp. 104.

Unio elongatulus — Marrone et al. (2019)

Unio thermalis Drouët, 1895
‘Monterosato, in sched.’ Drouët, 1895. J. de Conch. 43: 29, sp. 105.

Unio elongatulus rousii — Haas (1940)
Unio elongatulus — Marrone et al. (2019)

Unio istrianus Stossich, 1899
Stossich, 1899. Boll. Soc. adriatica scienze nat. Trieste 19: 50, text fig.

Unio elongatulus — Marrone et al. (2019)

Unio destructilis Kobelt, 1915
‘Villa’ Rossmässler, 1844. Icon. Land- und Süssw.-Moll. 2 (6): 31. [nomen nudum]
Villa in Kobelt, 1915. Icon. Land- und Süssw.-Moll. 20: 14, pl. 545, fig. 2781.

Unio elongatulus glaucinus — Haas (1940), Haas (1969)

Unio morlachicus Kobelt, 1915
Kobelt, 1915. Icon. Land- und Süssw.-Moll. 20: 11, pl. 544, figs. 2774-2776.

Unio elongatulus sandrii — Haas (1940)
Unio elongatulus pallens — Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio humerosus var. elongata Kobelt, 1915
Kobelt, 1915. Icon. Land- und Süssw.-Moll. 20: 9, pl. 542, fig. 2770.
(homonym of Unio elongata Lamarck, 1819; intro'd as intra-sp. of Unio humerosus Westerlund, 1890)

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio humerosus var. roboretana Kobelt, 1915
Kobelt, 1915. Icon. Land- und Süssw.-Moll. 20: 8, pl. 542, fig. 2769.
(intro'd as intra-sp. of Unio humerosus Westerlund, 1890)

Unio elongatulus glaucinus — Haas (1940), Haas (1969)
Unio elongatulus — Marrone et al. (2019)

Unio elongatulus Rossmässler, 1835
‘Mühlf.’ Rossmässler, 1835. Icon. Land- und Süssw.-Moll. 1 (2): 23, pl. 9, fig. 132.
Rossmässler, 1844. Icon. Land- und Süssw.-Moll. 2 (6): 27, pl. 56, fig. 751.
(reference to Unio elongatula C. Pfeiffer, 1825)

Unio (sec. Lymnium) elongatulus — Simpson (1900)
Unio elongatulus — Rochebrune (1903), Haas (1924)
Unio mancus var. elongatulus — Germain (1931)

Unio vindiflavus Lea, 1852
‘Küster’ Lea, 1852. Synopsis Fam. Naiades: 37.
‘Küster’ Lea, 1870. Synopsis Fam. Naiades: 59.
(error for Unio viridiflavus Küster, 1854)

Unio ovalis var. intercedens Gredler, 1860
‘Moll. Tirol II’ Gredler, 1860. unknown publication: 58. [nomen nudum]
(homonym of Unio intercedens Lea, 1857)

Unio elongatulus — Marrone et al. (2019)

Unio veillanicus Bourguignat, 1883
‘H. Blanc’ Bourguignat, 1883. Aperçu Unionid. Pénins. Ital.: 32.
(error for Unio veillanensis Locard, 1882)

Unio elongatulus — Marrone et al. (2019)

Unio cristoforii Locard, 1889
‘Adami’ Locard, 1889. Contr. Faune Malacol. Franc. 13: 153 [47].
(error for Unio cristophori Adami, 1886)

Unio palleus Locard, 1889
‘Parreys’ Locard, 1889. Contr. Faune Malacol. Franc. 13: 156 [50].
(error for Unio pallens Rossmässler, 1842)

Unio klecaki Westerlund, 1890
‘Drouët’ Westerlund, 1890. Fauna Paläarct. Binnenconch. 2(7): 114.
(error for Unio kleciaki Drouët, 1879)

Unio quellencci Kobelt, 1896
‘Drouët’ Kobelt, 1896. Icon. Land- und Süssw.-Moll. 7: 100.
(error for Unio quellenneci Drouët, 1895)

Unio quelleneci Kobelt, 1896
‘Drouët’ Kobelt, 1896. Icon. Land- und Süssw.-Moll. 7: 100.
‘Drouet’ Haas, 1940. Zool. Ser. Field Mus. Nat. Hist. 24: 125.
(error for Unio quellenneci Drouët, 1895)

Unio mancus var. elongatus Germain, 1931
‘Mühlfeld’ Germain, 1931. Faune de France 22: 725.
(error for Unio elongatulus Rossmässler, 1835)

Unio sabinensis Haas, 1940
Haas, 1940. Zool. Ser. Field Mus. Nat. Hist. 24: 127.
(error for Unio sebinensis Bourguignat, 1883)