Mac - X11 - emacs - meta - alt key

[David Rogoff]

Hi all.

I'm still getting used to my Mac and have a strange problem with emacs. 
When running Aquamacs on the Mac itself, the Alt/Option key is meta, 
which is what I expect.  However, I'm also remote accessing a Linux box 
via X11/NXClient.  When I run emacs (or xemacs) on in Linux, it looks 
like X11 has remapped the Mac Command key to be meta.  How do I put 
this back?

Thanks,

David