I agree both McCorley and McErlane seem to be of Irish Gaelic(IG) origin. However McErlean(Roddy's mum's name)as opposed to McErlane, seems to be of Scots Gaelic(SG)origin to me. The "lean" ending is a give away. The fact is, as I'm sure you realise, its difficult to be dogmatic about these things because if you go back far enough they were probably all Irish as we are told that it was ancient Irish tribes who first brought the Gaelic language with them to Scotland. In this way all Gaelic can be seen to have basically Irish origins.

Leaving aside the question of nationality, religious affiliation is a different matter again. Religion depends on various factors, such as time scale, ie. did emmigration occur before or after the "Scottish Reformation". For example if we take the name Maginess if the name holder's ancestors emmigrated from Scotland before the 1500s he will probably be catholic, but if they arrived after the 1500s he will probably be protestant. The other main factors were the Penal Laws and intermarriage(according to some researchers, this was much more common that many people today believe, especially between catholics and presbyterians - Oh for the good old times!!). The point I'm trying to make is that surnames in Ulster, whether they they be of IG,SG or whatever orgin are not always a sound indication of religion. I personally know of many protestants with names like: Murphy, O'Boyle, O'Neil, Kelly, Ennis, McIlwaine, Donnan, Feeney, Healey, Conor, Quinn etc, etc.(particularly on the Shankill Road and North Down). Moreover, I know of many catholics with names like: Adams, Hume, Bell, White, Smith, Hastings, Jones, Fitt, Carson, Stephens, Williams, Johnson etc. Its all a bit of a minefield. I find it fascinating. This name "crossover" thing is so common that I feel that we do not really understand the real nature of it. Its true origins are probably buried under centuries of bigotry and propaganda. (to "meself", surely there are more pleasant and fulfilling ways to test your testosterone than going to the quack!)