This ethnic group is located in the Ogooue River region in Gabon. The Duma were the great boatmen of the Ogooue. They believe in a God who made the world, in an immortal soul and in retribution for evil; they worship spirits and ghosts, and are under the sway of sorcerers and secret societies, to which even the authority of their chiefs must yield. Remarkable are their masks with flat surface for face, domed forehead, an angular nose, an interesting interplay of flat, convex, and angular forms. These masks are mostly polychrome, some with a painted design pattern. For the last half-century these masks have been used for celebratory dances associated with the major social rituals. Their former role is less well documented.