We found this orange/yellow one on the slopes of Cathair Mhic Dhiarmaid on Monday, in just two locations, a small group in one place, and this lone cap in the other. Both were on the open moorland in very damp places, and seemed to be growing on a substrate of rotting vegetation and dead grass. About the closest I can get to it is a young form of Bolbitius vitellinus, but the one we found is brighter in colour and lacks a distinct cap.
Perhaps it shouldn't worry me that I can't identify them, and I should be quite satisfied with admiring them for what they are. But.... what is it that gives one the urge to know what something is, to classify it?