I hypothesise that the name Meyn (my mother’s maternal surname) was previously written as O’ Meehan. The O’Meehan surname is derived from O’Meighan and the O’Meighans are a branch of the McIntyre line.

Meyn is a famous name in Northern Germany near the Denmark region and the name Meyn, seems to be the Scandinavianised version of the Celtic/Gaelician name O’ Meehan.

Link about the O’ Meighans:
http://www.surnamedb.com/Surname/Meighan

Previous to being Gaelicianised, Meehan/Meighan could have had the Milesian surname, Maithan/Maothan as their predecessor.