McCarron/McCarn County Tyrone
FYI, my great great grandfather was Felix McCarron of Donaghcavey Parish, County Tyrone. His surname was McCarron, yet he appears as McCarn in many records as this was and still is the local phonetic pronounciation of McCarron in the region (Dromore and Donaghcavey parishes). As to the origins of the name McCarron, I believe one of the more credible accounts is "Irish Names and Surnames," Rev. Patrick Woulfe, 1923 at http://www.libraryireland.com/nameshttp://www.libraryireland.com/names, searching for "Mac Carrghamhna" (derived from a posting by a Martha McCarn, since unlocatable)