From Ponce. (1968) (public domain):
Unexpanded basidiocarp globose, submerged until expanded when 3-6 cm.
wide; exoperidium split to about the middle into 7-10 unequal, acute
rays which are expanded and revolute, or partially involute; fleshy
layer bay-brown, continuous or rimose; outer layer covered with debris
held by the persistent, adnate mycelial layer, in old specimens
partially flaking away; base concave or plane; endoperidium
pedicellate, depressed globose, obovate or subpyriforme, glabrous when
old, farinose when young, grey to umber, up to 1.5cm diameter.
Peristome depressed, acute, fibrillose, surrounded by a pallid or
concolorous, fibrillose or silky zone; gleba chocolate; columella
almost obsolete; spores globose, 4-4.5um, fuscous, spines acute,
densely and coarsely warted; capillitium dark, long, simple, 5-5.3um,
some of the threads with rudimentary ramifications.