AETHALIUM: pulvinate, even, or somewhat irregular, unevenly swollen or inflated, lobate or compound, covered by an exceedingly thin, generally smooth, shining, but never white, pellicle or cortex, brown, from 10–60 mm. in diameter;
HYPOTHALLUS: white, often extending beyond the aethalium.
CORTEX: composed of the confluent tops of the component sporangia, often smooth, sometimes rough or perforated;
Pseudocapillitium walls within the aethalium perforated, forming a network of broad, membranous bands, or sometimes frayed into strands and slender threads