I take it also that Carnmoon isn't in fact an island? And what is the date of the birth-it looks like 24th of May to me, but the family thinks it was 27th.
There are 2 places named Carnmoon and 1 named Islands of Carnmoon in Co. Antrim. All are townlands (an Irish administrative land division). None is an island or on an island. They are all in the north of the county, between Ballymoney and the Giant’s Causeway. You can see them on the maps attached to Griffiths Valuation.
Day of birth looks like 24th to me. There are several possible explanations as to why the family may have come to believe it to have been the 27th. In the 1800s in Ireland people didn’t celebrate birthdays and often didn’t know exactly when they were born. Alternatively the father may have made a mistake with the date, registering the birth on the wrong day (I know someone alive today whose birthday in the 1930s was registered 6 weeks late and on the wrong day, according to his mother).
