For background on how the map was made (and its flaws), see the relevant blog entry.
|Guckian||Quite numerous: Leitrim. Ir. Mag Uiginn, possibly from Uiging, a Viking. This name occurs mainly in Ulster as MacGuigan and MacGuckin, q.v. MIF.|
|Mac Guaicín||Guckian: annamh: Liatroim. Féach Mag Uiginn.|
|Magookin||Very rare: Down. Variant of Mac Gookin, q.v.|
DEDs where Guckian and a second surname are found together