I've used poor wording. I appears that when xorg-server is built, the x11-drivers need to be rebuilt to work with it. This does not happen automatically. The build does not fail. It just does not happen.
The version of xorg-server is 18.104.22.1681-r2.
On Sunday I 'emerge --sync' and had problems. Perhaps I was not thorough enough, but I could not rebuild the drivers in a way that xorg-server would accept. I was also having a problem with 2 versions of eselect-opengl.
On Monday I 'emerge --sync' again and the eselect problem is no longer there. "emerge -aDu world" completes without error.
I found elsewhere that I needed to
emerge -av `qlist -I -C x11-drivers/`
I finally have access to the desktop as long as akonadi does not have problems.
thanks again for your help.