Closed pileus 10 x 20 mm high, cinnamon-brown to ochre, up to 35 mm wide when expanded. Veil present on pileus, visible as small, whitish, radially fibrillose flocks. Lamellae narrowly adnate, crowded, white to blackish. Stipe 35-65 x 1.2-2 mm, whitish, pubescent, somewhat white-felted at base when young.
  Spores [20,1,1] 11-13.4 x 6.8-7.7 x 6.2-7.1 µm (according to the original description 10.5-12.9 x 6.5-7.5(-8) x 5.8-6.5 µm), av. L= 12.1, av. B= 7.2 µm, Q= 1.55-1.85, av. Q= 1.70, ovoid, in part with slightly apical papilla; germ pore eccentric, c. 1.8 µm wide. Basidia 18-36 x 8-10 µm, 4-spored. Pseudoparaphyses 4-6 per basidium. Cheilocystidia first globose, 15-40 µm broad, later ellipsoid to broadly (sub)cylindrical, up to 70 µm in length. Pleurocystidia absent. Pileocystidia 65-115 (-140) x 10-30 µm, lageniform with cylindrical neck and equal to slightly broadened, 5-10 µm wide apex. Sclerocystidia absent. Veil on pileus consisting of 2.5 to 5.5 µm wide, somewhat diverculate, encrusted hyphae. Clamp-connections present.
  Drawning by H. Bender.

Habitat

  Usually gregarious on old saw-dust and small pieces of wood mixed with soil. Not known from the Netherlands.

Remarks

  Coprinus velatopruinatus, one of the species of subsect. Setulosi with a veil on the pileus that consists of cylindrical hyphae and seems closely related to C. heterothrix. The microscopical differences are the shape of the cheilocystidia which are mainly globose to ellipsoid and rarely lageniform to subcylindrical in C. velatopruinatus, but always lageniform in C. heterothrix and the smaller spores in last named species. Bender (l.c.) did not compare his new species with C. heterothrix, but with C. subimpatiens, C. callinus, and C. sclerocystidiosus.