(Hydnum repandum)
There are several English names for this species; "Wood Hedgehog", for example, is the one recommended by the British Mycological Society.
Toothed fungi are common among those species that form a flat crust on wood (the so-called resupinate fungi), but mushrooms that have teeth or spines on the underside of their caps are less familiar.
The patch of mushrooms shown here, all of the same species, was just to the south of a path through Whinny Hill Woodland; specifically, it was beside the part of the route that is shown in
NS3984 : Path through the woods, although the path there has been upgraded in the interval since that picture was taken.
The mushrooms are growing around the base of a beech tree, and probably in mycorrhizal association with it (meaning that the fine fungal threads that make up the mycelium, the more extensive underground portion of the fungus, are in a symbiotic association with the roots of the tree). Beech is one of the species of tree with which the Hedgehog Fungus commonly forms such an association.