The upper surface is usually convex and greyish white; underneath are blunt spines.  The margins are translucent and it has a jelly-like texture.  It has a tapering white/grey stem.

Wood Hedgehog Hydnum repandum and related species also have spines or teeth on the underside of the cap

Good field photographs, showing toothed undersides as well as upper surface; note habitat and substrate

decaying conifer stumps and felled trunks