We have cousins two or three generations back that changed his name from Zerilli to Zerilla. Family was from Terrasini and came to America. His entry into America from Ellis Island was Zerilli. Each time he came and went out of the country he is listed as Zerilli, and when his wife travels to and from America, Ellis Island Records lists that she's coming to be with her husband Zerilli. Yet, for Federal census, and for all intents and purposes he cnhanged his name to Zerilla very early on, if not from day one on American soil and his headstone along with wife and children, and their children are Zerilla. The family through the generations are very upstanding straight forward, fly right members of society of the highest respect. In Terrasini, there is no Zerilla, so why? What does a person think to change his name like that? Thanks for responding.
Sometimes on official documents the final 'i' has a curly loop that might lead someone in America who is copying the surname from document to believe it is an 'a'. If he was illiterate, and many were, he would not have known that the spelling in America was different from that in Italy. Ship manifests were written up by the Italian staff on the outgoing boat so they could read the writing easily. If it bothers you, change it back to the original. It was a simple clerical error.