Summary:
Features include 1) resupinate growth on wood, 2) a fruitbody that is a thin, flat, ochraceous to whitish, soft-waxy crust, 3) differentiation from others in genus by apically branched dikaryophyses and narrow, cylindric to allantoid spores that are aseptate or tardily 1-septate, and 4) basidia with two large sterigmata.

Microscopic:
SPORES 9-11(12) x 3-4 microns, cylindric to curved-cylindric, thin-walled, apiculate; PROBASIDIA 19-31 x 3-4 microns, at first cylindric, becoming subclavate or narrowly clavate, with basal clamp connections, producing 2 sterigmata to 17.5 microns long; hymenium smooth, consisting of densely packed basidia and dikaryophyses, the latter simple or more often irregularly branched apically, "projecting beyond the basidia, with basal clamp connections"; internal hyphae "thin-walled, smooth, conspicuous clamp connections present", (McNabb), SPORES 9-12 x 3-4 microns, cylindric, attenuated obliquely at the base depressed or a little curved, colorless, not septate; BASIDIA 30-45 x 3-4 microns, narrowly claviform, sterigmata divergent, 12-15 x 2.5-3 microns; hyphae 3 microns wide, thin-walled, clamp connections sparse, (Bourdot), SPORES 7-12 x 2.5-4 microns, allantoid, inamyloid; BASIDIA narrowly clavate when young, 20-25 x 5-6 microns, then producing two large, first obtuse, then acute sterigmata, 10-15 microns long and about 2 microns wide at base; CYSTIDIA none; HYPHAE monomitic, BASAL HYPHAE 3-4 microns wide, wall somewhat thickened, with clamp connections, hymenial branches 2.5-3.5 microns, thin-walled, with clamp connections, (Eriksson)

Notes:
Cerinomyces crustulinus has been found in BC, LA, and MI, (Ginns), France and Sweden, (McNabb), and Finland (Eriksson).

Synonyms and Alternate Names:
Polyporus biformis Fr. sensu Overh. non Fr.
Trametes cervina (Schwein.) Bres.