Mac Ailín
Mac AILÍN—IV—M'Aline, M'Alline, MacAllion, MacAllen, MacAllon, MacEllin, MacEllen, etc.; 'son of Ailín'; the name of a branch of the Campbells of Scotland, some of whom were brought over by the O'Donnells as fighting-men, about the middle of the 16th century, and settled in Tirconnell. This surname easily got confused with Mac Cailín, which see.
Alphabetical Index to Irish Surnames