I have done a lot of reseasch into my Dad's family history, and have had problems finding the parents of Ellis Pugh, from Dolgellau. A hundred years before the Ellis I'm researching, there was another Ellis Pugh who, hounded by Welsh suspicion of Quakers, emigrated to Pennsylvania, where he wrote the first book on the subject.
Bearing in mind that Welsh families tend to use the same christian names in every generation, I can only assume that I am descended from the ex-pat Ellis.
Being non-conformists, it is hard to find any records before the first census. I'll have to spend a day or two at Aberystwyth library I think, to find more information.