1) Agnation 2) Unilateral descent 1) Agnation 
(from the article `descent`) One method of limiting the recognition of kinship is to emphasize the relationships through one parent only. Such `unilineal` kinship systems, as ... descent group reckoned through only one parent, either paternal (patrilineage) or maternal (matrilineage). All members of such a group trace their ....
[n] - line of descent traced through the paternal side of the family
patrilineal, patrilineage 1. Designating or of descent, kinship, or derivation through the father instead of the mother. 2. Related to descent through the male line; inheritance of the Y chromosome is exclusively patrilineal.
agnation noun line of descent traced through the paternal side of the family
A group of male and female descendants of a male ancestor, each of whom is related to the common ancestor through male forebears.