Keesing's Typology of Descent:

Patrilineal Descent: (or agnatic) descent from an ancestor down through a series of male links (i.e., though the ancestor's son, his son's sons, his son's sons' sons, etc.)

Matrilineal Descent: (or uterine) descent from an ancestress down through a series of female links (through daughter, daughter's daughter, etc.)

Cognatic Descent: descent from an ancestor or ancestress thorugh a series of links that can be male or female or any combination of the two.

Double Descent: a system whereby two sets of social groups or categories exist (for different purposes) in the same society, one based on patrilineal descent and the other on matrilineal descent (so a person belongs to his/her father's patrilineal group and his/her mother's matrilineal group).

Tuzin's Typology of Descent:

Unilineal Descent: The principle whereby descent is traced either through the male line ("patrilineal") or the female line ("matrilineal"), but not both (NG-163ff.; RF-97ff.)

Double Descent: The principle whereby descent is traced through the male line for certain prescribed purposes, and through the female line for other prescribed purposes; also called Double Unilineal Descent (NG-169; RF-131, 146).

Non-Unilineal Descent: The principle whereby descent is reckoned by means other than exclusively through the father and his male ancestors or the mother and her female ancestors (RF-147; NG-200ff).

Ambilineal Descent: The principle whereby descent is reckoned through male or female links without set order (NG-198).

Bilateral Descent: The principle whereby descent is traced equally through males (i.e., father) and females (i.e., mother). Also called Cognatic. English kinship embodies such a descent principle (NG-198; RF-146ff).