Mo. Rev. Stat. § 474.020: Lineals take per capita and per stirpes, when.

When several lineal descendants, all of equal degree of consanguinity to the intestate, or his father, mother, brothers and sisters, or his grandfathers, grandmothers, uncles and aunts, or any ancestor living and their children, come into partition, they shall take per capita, that is, by persons; where a part of them are dead, and part living, and the issue of those dead have a right to partition, such issue shall take per stirpes; that is, the share of the deceased parent.