When growing under the log the upper side of the cap is against the wood and it is said to be resupinate.
resupinate, spread over the matrix, the fruiting surface external and the pileus next the wood.
resupinate, inverted, or appearing as if upside down, or reversed.
It is resupinate, the cap being beautifully zoned as you see in Figure 351.
This is a very small plant, resupinate, membranaceous, and it is so named because of the milk-white color underneath.