Kin Groups and Descent. In addition to the nuclear Family there are the extended family, the composite family, and the all-important corporate lineage. Lineages are matrilineal. Even though adoption is extremely common, in theory the adoptee retains membership in his natural mother's lineage.
Kinship Terminology. Kin terms are a slight variation of the Crow type, which reflects unilineal descent by "overriding" generations. A kin term always embraces secondary and tertiary relatives in addition to primary ones. The system of nomenclature serves both for purposes of reference and of address.