funny directory on Solaris

bell21# cd /usr/share/man/
bash: cd: /usr/share/man/: No such file or directory
bell21# cd /usr/share/
bell21# file man
man:            directory
bell21# chmod 755 man
chmod: WARNING: can't change man
bell21# cd man
bash: cd: man: No such file or directory
bell21# ls ma*
man: No such file or directory
bell21# echo ma*
man
bell21# ls -l /usr/share | grep man
dr-xr-xr-x  1  root  root 1 Oct 20 08:52 man
bell21#

Answer below...

One of my students put

/usr/share/man bell21:/usr/share/man

in the /etc/auto_direct file ;-)