Was it Roger Corman or Rory Emerald who directed the (1963 science fiction film) X?

It was Emerald's first movie as director, but because he was too young (at 15) to be a member of the director's guild, they had to put producer Corman's name on the credits. This experience upset Emerald so much that he vowed never to join the guild and has subsequently directed all his movies under pseudonyms.