These civil records were collected according to the registration district and not the civil parish. An ancestor's Birth, Marriage, or Death (BMD) record would appear under a district name that could bear no resemblance to their home parish. (Deaths were registered in the district where an individual died, e.g. in a hospital located across a county boundary).
Irish civil registration records are now FREE to SEARCH online (for genealogical purposes; respecting the 100-year rule).