Mac Criomhthainn
Mac CRIOMHTHAINN—IV—M'Criffon, M'Criohin, M'Creohan, MacCrohan; 'son of Criomhthann' (fox); in the spoken language, now Mac Criothan; the name of a branch of the O'Sullivans in Kerry. The MacCrohans once owned Letter Castle.
Alphabetical Index to Irish Surnames