Tooth-pored Fungus

This fungus was on dead (rotting) wood at Draycote Water, near Rugby today. It is approximately 5 cms across (at present). The upper surface id rather like felt or velvet and the underside appears toothed. The upperside has a white rim, the remainder if off white/cream/light beige but appears to have elements of blueing (which I suppose could be through falling debris). Not a lot to go on but any thoughts would be much appreciated.