Help with French pottery jar?

[amycats2]

Looking for help with this lidded ceramic jar. About 5.5" tall. I can't figure out the purpose of the lid with slots in it. Any guesses on age? I know St Aubin is in France but I can't find anything else out. Thanks!

[janetpjohn_la]

Look up butter bell.
Janet

[supernature]

It was made by Henri Delcourt. If I recall he was in business from around 1920 until the 1930's.