Where did you find that coat of arms? There is no authentic coat of arms for Carty, according to the Hearaldic Office in Dublin, who base their records on those kept by the UK in London, who administerd such since 1200AD from Dublin Castle. Whoever sold you them conned you, as many unoffical arms were drawn by modifying the Mc Carty arms.
I have to set the record straight here, Carty comes from O'Carty, a sept from Wexford, members of the old Clan Eoghanachta of south Munster, which also included O'Driscolls, O'Sullivans, O'Donoghue's, Mc Donoughs etc.
The predominant clan in the Clan Eoghanachta was the Mc/Mac Carthys, a completely different family entirly, who ruled with an iron fist before the coming of the English.
Carty in Irish Gaelic is O'Carthaigh, descendent of Cathaigh (the loving man), a prince who was burned at the stake in 966 or so, the crime does not survive in folklore. Judging by the name, modern historians assume he was a ladies man, and was killed for fooling around with someone elses wife. Good thing Bill Clinton wasn't around in those days! What his real name was, we dont know.
The Cartys are still strong in Ireland, a John Carty is a MCC for Fianna Fail in Mayo, I ran as an independent in Birr, there are many hurlers in Wexford etc., etc.
A point to note is that the Carthys of North Longford are really Carty's. Based in Aughagreagh, they came from Kildare, after being evicted for not paying rent! Three brothers (John, Thomas and ?) settled on Aughagreagh, two being childless, and thomas having family, after whom six generations held the farm before my father John sold it to John Kelly in the late 60's. Our name was spelt as Carthy until a court case involving an assault over a land dispute was lost on the basis that one party brought the charge against a Carthy, when the name was Carty, proved by the Gealic spellings in the landlord records!
Now, theres history for you!
In the Gaeltacht settlement in meath, there are also lots of Cartys