Unio orientalis Lea, 1840
Lea, 1840. Proc. Amer. Phil. Soc. 1: 285.
Lea, 1842. Trans. Amer. Phil. Soc. 8 [O. 3]: 221, pl. 18, fig. 38.
Type(s): HOLOTYPE USNM_86058, Java.

Nodularia (s.s.) orientalis — Simpson (1900)
Rectidens orientalis — Frierson (1911), Simpson (1914), Modell (1942)
Elongaria (s.s.) orientalis — Haas (1913), Thiele (1934), Haas (1969), Haas (1969)
Elongaria orientalis — Haas (1940), van Benthem Jutting (1953), Graf & Cummings (2007), Bogan (2010), Affandi et al. (2013), Zieritz et al. (2018), Pfeiffer et al. (2021), Graf & Cummings (2021), Sahidin et al. (2021)

Unio productus Mousson, 1849
Mousson, 1849. Land-Süßw.-Moll. Java: 93, pl. 17, figs. 3-5.
(renamed Unio productior Lea, 1852; homonym of Unio productus Conrad, 1836)

Nodularia (s.s.) orientalis — Simpson (1900)
Elongaria (s.s.) orientalis — Haas (1913), Haas (1969)
Rectidens orientalis — Simpson (1914)
Elongaria orientalis — van Benthem Jutting (1953), Pfeiffer et al. (2021)

Unio productior Lea, 1852
Lea, 1852. Synopsis Fam. Naiades: 29 (footnote).
(new name for Unio productus Mousson, 1849)

Nodularia (s.s.) orientalis — Simpson (1900)
Elongaria (s.s.) orientalis — Haas (1913), Haas (1969)
Rectidens orientalis — Simpson (1914)
Elongaria orientalis — van Benthem Jutting (1953), Pfeiffer et al. (2021)

Unio bithynicus Kobelt, 1893
Kobelt, 1893. Icon. Land- und Süssw.-Moll. 6: 96, pl. 179, fig. 1128.

Unio (sec. Lymnium) bythinicus [sic] — Simpson (1900), Simpson (1914)
Elongaria orientalis — Haas (1940), van Benthem Jutting (1953), Pfeiffer et al. (2021)
— Haas (1969)

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 productus form arcuatus Mousson, 1849
Mousson, 1849. Land-Süßw.-Moll. Java: 93, pl. 17, fig. 4. [infra-subsp.]
(intro'd as intra-sp. of Unio productus Mousson, 1849; homonym of Unio arcuata Bouchard-Chantereaux, 1838)

Elongaria orientalis — van Benthem Jutting (1953)

Unio productus form fragilis Mousson, 1849
Mousson, 1849. Land-Süßw.-Moll. Java: 93, pl. 17, fig. 5. [infra-subsp.]
(intro'd as intra-sp. of Unio productus Mousson, 1849; homonym of Unio (Leptodea) fragilis Rafinesque, 1820)

Elongaria orientalis — van Benthem Jutting (1953)

Unio productus form normalis Mousson, 1849
Mousson, 1849. Land-Süßw.-Moll. Java: 93, pl. 17, fig. 3. [infra-subsp.]
(intro'd as intra-sp. of Unio productus Mousson, 1849)

Elongaria orientalis — van Benthem Jutting (1953)

Lamellidens evanescens Paravicini, 1935
‘Mousson’ Paravicini, 1935. Arch. Moll. 67: 175.
(misidentified reference to Unio evanescens Mousson, 1849)

Elongaria orientalis — van Benthem Jutting (1953)