I think John is right, those look a lot like Coprinopsis atramentaria, the alcohol inky, to me. (Coprinopsis atramentaria is the new name for Coprinus atramentarius.) Check out this link to mushroomexpert:
The stems are fat and there tall not short the caps did turn to goo stems still intact but it could maybe be a new ink cap? No one can find them cheeked in several books not there can I mail someone spore prints to figure this out?