Landuma, group of some 20,000 people located principally in Guinea, 30 to 60 miles (50 to 100 km) inland along the border of Guinea-Bissau. Their language, also called Landuma or Tyapi, belongs to the Atlantic branch of the Niger-Congo family and is related to Baga. The Landuma are agriculturalists—corn (maize), millet, groundnuts (peanuts), and rice being the major crops. Social organization centres in a paramount chief, with villages governed by subordinate chiefs. Marriage is frequently polygynous, and inheritance goes to members of the mother’s family. Most are Muslims with about 10 percent practicing their traditional religion centred on the activities of departed spirits.