A number of years ago I had begun to explore Celtic mythology and in my readings I stumbled across a reference to Mug Ruith under an ancient Gaelic surname, the translation of which is "Son of ancient wisdom". I cannot recall the volume in which I found the reference and a thorough search of the internet has born no fruit. Thus I ask if anyone is familiar with this reference and if so, the Gaelic surname in question. I believe it resembled MacSenghesa though I know this spelling to be inaccurate. Any help would be greatly appreciated.