The inkcaps are a family of mushrooms which spread their spores by deliquescing. Their caps are transformed into a black slime, which is indeed the pores.
Another name for this species is lawyers wig. At a certain stage in their decomposition the caps can look very like a barrister’s less than pristine headgear (below and especially above).
The specimens pictured here show the range of stages from newly emerged to almost completely deliquesced.