Welsh patronymic surnames take on three forms:
1. A masculine name as it is (particularly common for masculine names ending in “s”, though not always that way). Examples: James, Thomas, Lewis, George, Owen, Griffith, Morgan.
2. A masculine name followed by a possessive “s.” Examples: Williams, Jones, Evans, Edwards, Matthews, Roberts, Hughes, Harris (son of Harry), Davies or Davis (son of David/Dafydd).
3. A masculine name beginning with the prefix “ap” or “ab” (the “a” is usually dropped in the modern form). Examples: Powell (ap Howell), Pritchard (ap Richard), Price (ap Rhys), Bowen (ab Owen), Bevan (ab Evan), Pugh (ap Hugh).