Genus Neorhynchoplax Sakai, 1938

Type species by subsequent designation by Holthuis (1968): Rhynchoplax introversus Kemp, 1917 . The genus Neorhynchoplax, the richest hymenosomatid genus, currently contains more than 30 species, all from the Indo-West Pacific (Ng et al. 2008, 2011: 53; Hsueh 2018: table 1), with nine species described from Indian waters (Alcock 1900; Kemp 1917; Chopra & Das 1930; Ng et al. 2011: table 2; Rahayu et al. 2020).

Several species of Neorhynchoplax are regarded as true freshwater species: N. dentata Ng, 1995 (Sarawak, Malaysia), N. inermis Takeda & Miyake, 1971 (Palau Islands), N. introversa (Kemp, 1917) (Kiangsu, China), N. kempi (Chopra & Das, 1930) (Basra, Iraq), N. prima Ng & Chuang, 1996 (Pulau Bintan, Indonesia), N. frontalis (Lucas & Davie, 1982) (NE Queensland, Australia), N. hirtirostris (Lucas & Davie, 1982) (NE Queensland, Australia), N. nasalis (Kemp, 1917) (Kiangsu, China), N. pageti Pretzmann, 1975 (Madampe, Sri Lanka), N. patnahi Ng, Nesemann & Sharma, 2011 (Patna, Bihar, India), N. thorsborneorum (Lucas & Davie, 1982) (NE Queensland, Australia), N. yaeyamaensis Naruse, Shokita & Kawahara, 2005 (Yaeyama Islands, Japan) (see Shen 1932; Chuang & Ng 1994; Ng et al. 1999, 2008, 2011; Naruse et al. 2008b; Hsueh 2018). Others species are from brackish waters or are marine intertidal and marine subtidal.