My wife's family legend says that the Melancons (Melansons in the Maritimes) were actually Scottish who assimilated with the Acadiens in Nova Scotia after the Scots turned the colony over to the French, but my MIL has found evidence that the Melansons were actually from Yorkshire!

I did find recently that Melanson is listed as a "sept" of the Clan MacMillan:

http://www.clanmacmillan.org/Melanson.htm

Cheers,

Todd