Pokemon whose evolution are in a different generation
The answers will consist of a pair of Pokemon, one that evolves into the other, that don't share a generation. Regional forms are considered to be part of the generation they were introduced, not when the base variant was introduced.
If it's all there are many missing:
Meowth->Perrserker
Pikachu->Alolan Raichu
Basculin->Basculegion (questionable)
Just some examples not inclusive
Stantler is Gen 2