I found an aerodactyl, larvitar, gastly and cranidos in eliot cavern.
It took long time to find them, but i finally caught them! ^^
Don't give up!!

Gastly and aerodactyl: in the front of the end to the caveren.
Larviter: i found larvitar in the light sand.
Cranidos: in the light sand there is a staircase, behind the stairs is cranidos somewhere.
(that staircase there goes down)

I came from denmark, so sorry, if you can't understand it! Xd'

Just go to bird town then go to the veg patch and wander about that area, you should find
one there, i did
Xd

Paras snubbull sandshrew and nidoran at the bottom left area at partyland. I found kecleon
near the pokemon center in rock town.