For background on how the map was made (and its flaws), see the relevant blog entry.
|MacGuirk||numerous: Monaghan, N Leinster etc. Ir. Mag Oirc (SI); Mag Coirc (SGA). First name Corc (crimson) was popular, so perhaps it is to be preferred, but see also Mac Gurk.|
|MacGurk||numerous: Tyrone-S Derry etc. Ir. Mag Oirc. Mac Lysacht is very positive about this name and it was an important group descended from Niall of the Nine Hostages in 5 cent and located in Tyrone.MIF.|
|MacQuirke||rare: Dublin. Ir. Mac Coirc. Corc is an early first name meaning, perhaps "heart" or "red". See Quirk. GPN.|