Scottish surnames, but Roman Catholic and Irish?

[JQP4545]

http://www.immigrantships.net/v13/1800v13/dukeofnorthumberland18520629.html

I was just wondering if someone could help me with the origin of these surnames? My ancestors came from Ireland and were Catholic, but many of the surnames appear to have Scottish and English origin. How is this possible?

[JQP4545]

Answered my own question: http://en.wikipedia.org/wiki/Gallowglass

[Graham]

The Scots have intermingled with the irish like forever. I mean you get proper Scottish surnames in the Republic that are Catholic. Plenty in the top 100. Many not gallowglass.