Harpies , conventionally associated through the medium of the Roman poets with the human-headed bird-form which really denotes the Siren, are found invariably on vases in the form of winged women. They are, as has been elsewhere noted, associated with the Boreades as symbolical of evil and good influences of winds, and probably should be regarded as personifications of the southern breezes (the malevolent influence of which is seen in the sirocco). Traditionally they were supposed to guard the Garden of the Hesperides in Africa, whence the hot baleful winds come. The story of Phineus is probably to be explained on these lines. A Harpy appears at the recovery of Zeus' golden dog from Pandareos.