(Νηίς), a daughter of Zethus, or of Amphion by Niobe, from whom the Neitian gate at Thebes was believed to have derived its name (Schol. ad Eurip. Phoen. 1104). According to Pausanias Neis was a son of Zethus (9.8.3).
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890