Part of Co Mayo around Ballina was formerly part of Co Sligo, which is confusing to some, but you may want to look in both counties. My family came from Ballina...MEARS, FORD,FOY, MANLEY. My dna matches to some named GARRITY/GERRAGHTY, also GALLAGHER, BARRETT, O'NEIL, KELLY, and others. If you are looking at church records, try Kilmoremoy Parish. I also have BRYAN/O'BRIEN in my tree, but don't know where they were from.