Hydrophilus unguicularis (Régimbart, 1902a) *
Stethoxus (s. str.) unguicularis Régimbart, 1902a: 213, pl. 7, fig., 23.
Hydrous (s. str.) unguicularis: Zaitzev 1908a: 366; Mukhopadhyay 2015: 392.
Hydrophilus unguicularis: Hansen 1999a: 233.
Type locality: Type locality is not specified in the original description (see Hansen 1999a).
Distribution in India: Uttar Pradesh (Sultanpur).