the basic geo structure in Finnish countryside is farm > village > parish (> country). We usually do not mark the entities beyond parish because those have changed several times over centuries, in fact we are currently having another change. And there are very few places with duplicate names. If it helps you you can choose one of the divisions in use at some particular time. Like for example the values in dropdown list at Hiski http://hiski.genealogia.fi/hiski/21084y?en
In Hiski, after you choose Maalahti - Malax, there is a link More information about this parish and the next page states that there are only 2 villages in Malax: Yttermalax, Övermalax.
For more complete information http://digi.narc.fi/digi/index.ka?lang=en_US
-> link search engine -> http://digi.narc.fi/digi/search.ka
-> write Maalahti, click search -> scroll results forward until you hit
Maanmittaushallituksen maakirjat ja kruununmaaluettelot -arkisto >
Korsholman kihlakunta 1875-1875 (74:1)
Click-> click page 10 -> http://digi.narc.fi/digi/view.ka?kuid=14231
which starts the list of villages and farms in 1875 . First column has village, 8th the farm name, notes explain the official status of the farm. This is a list for tax purposes.