Unsure what type of fungus this was. It was a large clump comprised of many individual fungi, with what appeared to be smooth surfaces, sighted on the side of a fallen Cork Oak. One clearly visible in the images appeared to be balloon-like. Other clumps with slightly different colouring were sighted on a cut down Cork Oak and are covered by following sighting 4573879. Thanks to Barbara for the initial sightings.
This (and the related sightings) may show partly dried examples of a species of Exidia or Tremella (and some, not sure if all, brown Tremellas have been shifted to Phaeotremella).