this general type of social organization is now known as the mara type, after one of the tribes in the area. the kinship structure of these tribes is of the central australian aranda type in which the kin are grouped into four patrilineal lines of descent stemming from the father's father, father's mother's brother, mother's father, and mother's mother's brother. in the grouping of the kin into larger divisions under this mara type of organization, the father's father's and mother's mother's brother's lineages together form one named patrilineal moiety, while the father's mother's brother's and mother's father's lines form the other moiety. each one of the four patrilineal descent lines accordingly constitutes a patrilineal semi-moiety. the tribes of this area recognize these semi-moieties as absolute social segments, and give to each a distinctive name.