Fungus inside dead tree

Fungus inside dead tree

Observation - Fungus inside dead tree - UK and Ireland. Description: I am trying to give more information and betterr photograph of a previous observation. The fungus is fanshaped about 50 cm across 10cms thick to 5mm at its edge.It was growing in a dead horse chestnut, which has been felled and cut up. Lower down the bole

I am trying to give more information and betterr photograph of a previous observation. The fungus is fanshaped about 50 cm across 10cms thick to 5mm at its edge.It was growing in a dead horse chestnut, which has been felled and cut up. Lower down the bole there is another fungus (the same). The top surface is white and lumpy . The underside has fine pores which are an orange colour. I can see 4 distinct rows of gills, seperated by a white strip. between 1&2mms. On the top surface the spongy surface has tiny indentations,I do not think they are oores