It will be best to examine here some typical Irish pedigree that we may more readily understand the system in its simplest form, and see how families branch from clans, and clans from stems. Let us take, then, the first pedigree of those given at the end of the Forus Feasa, that of Mac Carthy Mór, and study it as a type. This pedigree begins with Donal, who was the first of the Mac Carthys to be created Earl of Clancare, or Clancarthy, in 1565. Starting from him the names of all his ancestors are traced back to Eber, son of Milesius. Passing over his five immediate ancestors, we come to the sixth. It was he who built the monastery of Irriallach on the Lake of Killarney. The seventh ancestor was Donal, from whose brother Donagh come the families of Ard Canachta and Croc Ornachta. The tenth was Donal Roe, from whom come the Clan Donal Roe, and from whose brother, Dermot of Tralee, come the family of Mac Finneens. The eleventh was Cormac Finn, from whom come also the Mac Carthys of Duhallow and the kings of Desmond; while from his brother Donal come the Mac Carthys Riabhach, or Grey Mac Carthys. The thirteenth was Dermot of Kill Baghani, from whom come the Clan Teig Roe na Sgarti. The fourteenth was Cormac of Moy Tamhnaigh, from whose brother Teig come the Mac Auliffes of Cork. The fifteenth was Muireadach, who was the first of the line to assume the surname of Mac Carthy, which he did from his father Carthach, from whom all the Síol Carthaigh [Sheeol Caurhy], or Seed of Carthach, including the Mac Fineens, Mac Auliffes, etc., are descended. The seventeenth was Saerbhrethach, from whose brother Murrough spring the sept of the O'Callaghans. The nineteenth was Callaghan of Cashel, king of Munster, celebrated in Irish romance for his warfare with the Danes. The twenty-third was Snedgus, who had a brother named Fogartach, from whose son Finguini sprang the Muinntir Finguini, or Finguini's People. The twenty-eighth was Falbi Flann, who was king of Munster from 622 to 633, from whose brother Finghin sprang the sept of the O'Sullivans. The thirty-second was Angus, from one son of whom Eochaidh [Yohy] Finn are descended the O'Keefes; while from another son Enna, spring the O'Dalys of Munster--he was the first king of Munster who became a Christian, and he was slain in 484. The thirty-fourth was Arc, king of Munster, from whose son Cas, spring the following septs: The O'Donoghue Mór--from whom branched off the O'Donoghue of the Glen--O'Mahony Finn and O'Mahony Roe, _i.e._, the White and Red O'Mahonys, and O'Mahony of Ui Floinn Laei, and O'Mahony of Carbery, also O'Mullane[6] and O'Cronin; while from his other son, "Cairbré the Pict," sprang the O'Moriarties, and from Cairbré's grandson came the O'Garvans. The thirty-sixth ancestor was Olild Flann Beg, king of Munster, who had a son from whom are descended the sept of O'Donovan, and the O'Coiléains, or Collinses. And a grandson from whom spring the O'Meehans, O'Hehirs, and the Mac Davids of Thomond.