What type of mushroom/fungus is this?
These are shelf (or bracket) fungi. They love dead or diseased wood, and are as common in woods as dirt.

Yours are kind of in rough shape (it looks like they're experiencing some problems of their own.) It's hard without examining a specimen to determine exactly which it is. 



Some are edible, some are beautifully colored, some are hard, some soft, some plump, etc. But they are all shelf fungi.