The towns that used to belong to Oaza Nishinaka have place names prefixed by 'Nishinosho' or 'Nakagawara,' while those which used to belong to Oaza Ishijima have place names prefixed by 'Ishihara' or 'Shima.'
なお、西中は「西ノ庄」と「中河原」、石嶋は「石原」と「嶋」の合成地名である。