Dune valley; Interdune areas filled by a lake are called Dund in India; Interdune horseshoe depressions between barchans or barchanoid ridges, especially where dunes are pressed closely on one another in such a way that the horns of one barchan join with the foot of the leeward dune, are called Fulji in Arabia (Glenn 1979); Open interdune corridors are called Couloir in North Africa