It has been a glorious day here in Darkest Northumberland, the onset of Autumn didn't prevent 11 hours of wall to wall sunshine!
I am not certain about this one though. I think that it is probably a Sickener (Russula emetica), which while not poisonous, as the name suggests, induces vomiting! A large fungi, at about five inches in diameter in this mature state, I thought that the gills were really interesting, so strongly structured but just so delicate.
If you look closely, you can just make out some tiny flies sticking to the gills. I can't decide if they were just stuck or had been laying eggs?