For background on how the map was made (and its flaws), see the relevant blog entry.
|Crum||Very rare: Antrim. Scottish. SS.|
|Mac Cruim||Mac Crum, Crum: cuíosach líonmhar: an Dún & rl. Sloinne Albanach ó Ile (Islay).|
|MacCrum||fairly numerous: Down etc. Scots Gaelic Mac Cruim, crom, bent, stooped. A Scottish name associated with Islay.|
|MacCrumb||Very rare: Belfast. As Mac Crum.|
DEDs where McCrum and a second surname are found together