This was on the underside of a Pitch Pine branch in a pine grove on Cape Cod. We thought it was definitely Sebacina at the time, but then I got it home and looked at it and the microscopic features tell a different story. So... The fruiting body is resupinate: appressed to the substrate and it covers the surface of other detritus as you can see from the pics. It's grayish white, waxy and very cartilaginous with a smooth - tuberculate surface and finely pruinose under magnification. Some areas are opaque while others are more transparent. It peels away from the substrate pretty easily and breaks up into waxy clumps. It's about 1mm or so thick with a white cottony subiculum in places. The margin is diffuse and fiberous, white. I can't say what kind of rot it produces from my field observations.