At university, my supervisor was a mycologist, who used 'funj-eye' as the plural of fungus. My edition of the Oxford English agrees with him, and I defer to both. A few years ago, I
heard the head of mycology at Kew using 'fun-ghee'. He should have known better! Scientific eminence does not mean authority in matters of English pronunciation. It is possible, though, that later editions of the OED, or other dictionaries, may have accepted 'fun-ghee' and 'fun-guy'. I don't think there are any real transatlantic issues here.
