Actually, on my Ubuntu 14.04 (it doesn’t use “xfs”), it’s probably “gsfonts-x11” and/or “xfonts-base” and/or “xfonts-scalable” and/or “xfonts-100dpi” and/or “xfonts-75dpi” packages.
Then, for “better appearance”, edit the “${ROOTSYS}/etc/system.rootrc” file and set “X11.UseXft:” to “yes” (by default it is “no”).