I don't have a difinite answer to this, but i know Bela became a U.S. citizen in the early '30s, several years before his son was born. He probably legally changed his name to Lugosi at that time so Bela Jr.'s legal last name would have been Lugosi also. I don't know where "George" came from, but since their first names are both Bela, I think "Jr." is just used as a simple distinction. In his personal life, I think he goes by Bela G. Lugosi.