ancestral deity Enki is to be distinguished from the better known god of the same name, who is associated with fresh water. Wilfred G. Lambert has suggested that the latter name had a different etymology, and due to the presence of an omittible g in spellings such as dEn-ki-ga-ke4 assumed that instead of ki, "earth", it was formed with the element kig, of unknown meaning. Jacobsen instead explained the two names as having slightly different meanings from each other, "lord earth" and "lord of the earth". The equation of Enki and Ninki with Ea (Enki) and Damkina (Damgalnuna) in an Emesal vocabulary is isolated and presumably a mistake, and the Emesal forms of the names of the two Enkis, respectively Umunki and Amanki, are not identical. Position in Mesopotamian mythology According to Christopher Metcalf, the tradition regarding Enlil's parentage which involved the Enki-Ninki deities is now considered conventional, though relevant sources remain difficult to interpret. Based on the meaning of the names Enki and Ninki, it is presumed it was related to the belief that earth was a primordial element from which everything else emerged. However, Enlil's parentage presumably varied between traditions. He was alternatively regarded as a son of Anu, as attested for example in an inscription of Lugalzagesi. Two sources which include both the pairs Enki and Ninki and An with either Urash or Ki, with the latter placed before them, are also known, and presumably reflect the belief that the coupling of earth and heaven preceded the emergence of the ancestors of Enlil. A further deity who could be regarded as Enlil's father was Lugaldukuga, a figure associated with the “holy mound” (duku). While Ninlil can be mentioned alongside Enlil in the lists enumerating his ancestors, these deities are never described as the ancestors of both of them, possibly to avoid the implications of incest between them. Wilfred G. Lambert suggested that an alternate interpretation of the lists might have been that each "generation" evolved from the previous one, with Enki and Ninki slowly morphing into Enlil and Ninlil, similarly with no implications of incest. The ancestors of Enlil were associated with the underworld. However, available sources do not explain how they came to reside there. Andrew R. George suggests that their placement in the underworld simply reflected the fact they were believed to be no longer active. A myth in which Enki and Ninki were banished