Crust fungus
A pale peach crust fungus, possibly Eichleriella deglubens. It shows some white hairs and a slight tendency to turn over (reflex) in the top of the above photo.
The tree it was growing on was fairly small and looked dead. Some of its twigs had 'wings' giving them a cross-shaped cross section which suggests it might be an elm (Ulmus sp).
Photos taken in the field below Chazey Wood, near Caversham, UK, on 2012-01-09.