Tremella mesenterica growing on a branch from a broad-leaf tree.
I took the following specimen home with me:
And it yielded the following spores (magnification x600, field width 86um):
The large ellipsoidal spores are about 13.5 x 9um which agrees well with the range 10.0–16.0 x 6.0–9.5um given for Tremella mesenterica here. The numerous small spores may be contamination from the green lichen that covered most of the branch.
First photo and specimen taken in Whiteknights Park, Reading, UK, on 2014-02-15.