Ó Lachtna
Ó LACHTNA—I—O Laghna, Loughney; 'descendant of Lachtna' (grey, dun); the name of a family of the Ui Fiachrach, who were chiefs of the Two Bacs and of Glen Nephin, in the barony of Tirawley, Co. Mayo; now very rare, having been almost universally replaced by the diminutive form Ó Lachtnáin, which see.
Alphabetical Index to Irish Surnames