For each two-seat county constituency in the Irish House of Commons, the election was held in the county town, with a separate polling booth for electors resident in each barony or half-baroiny. The single-seat divisions into which the Redistribution of Seats Act 1885 split most Irish county constituencies were defined largely or exclusively in terms of the baronies which they comprised; however, in some cases a barony was split parish by parish between two divisions. The 1891 census was the last for which returns were aggregated by barony as well as by Union and DED; the 1901 census used only the latter classification, though it and the 1911 census included the barony in the detailed returns.