Lawyer's Wig

Coprinus comatus, the shaggy ink cap, lawyer's wig, or shaggy mane, is apparently a delicious mushroom, but you will probably never find it in the supermarket as it has an extremely short shelf life. 
I found a couple of these while out for a walk today. The walk ended up longer than I had originally planned, getting close to 10 miles, with a couple of decent hills to climb too.