about the unicode symbols in delimiter dialog

[Uwe Stöhr]

With Abdel's latest change from images to unicode symbols for the delimiter dialog the following 
symbols are no longer displayed in my system:

\Up(Down)arrow
\l(r)deil
\l(r)angle
See attached screnshot.
Do I need a special font for this? If yes LyX should ship it.

regards Uwe