... In two of the Welsh poems attributed to the bard Myrrdin, the Avallenau and the Hoianau, certain prophetic words are put into the mouth of one designated as hwimleian, huimleian, chwimpleian, chwibleian, chwivleian, a word which is translated Sibyl by Skene, Nymphe by San Marte.  In an interpolated text of the Avallenau contained in the Myvyrian Archaiology there are a few lines describing her, which are available in San Marte's translation:—

Die Nymphe welche erscheint und verschwindet weissagt deutlich
In Bildern von unruhigen Zeiten, die sicherlich kommen werden.

This personage is regarded by Villemarqué, by Maury, who accepts Villemarqué's statements, and by Thomas Price as the original for the Vivian of the romances.  Vivlian, Villemarqué says, is a name changed by the romancers into Vivian.  Price admits that "it is true there is not much resemblance in the names," but adds that Chwifleian by the French writers of romance might be easily modified to Viviane.  The word Hwimleian in its various forms, according to Gaidoz, means neither sibyl or nymph, but is a proper name of unknown etymology... (Studies in the Fairy Mythology of Arthurian Romance, Paton, 1903).