Closed pileus ellipsoid, cylindrical ellipsoid or subglobose, up to 20 mm high and 13 mm wide, completely covered with white, powdery veil; veil at margin, particularly in early stages somewhat more hairy-floccose; expanded pileus up to 35 mm wide, conical or convex, finally applanate with reflexed margin. Lamellae, L = 22-30, l = 0-3, free to narrowly adnate, white at first, then grey to black. Stipe up to 100 x 3-5 mm, slightly attenuate upwards, white, flocculose from veil; at base up to 6 mm wide, often brownish, with white velar flocks. Smell absent. Spore print black with violet hue.
  Spores [40,2,2] 9.6-15.4 x 6.5-8.7 x 7-7.5 µm, Q = 1.45-1.80, av. Q = 1.50-1.55, av. L = 11.9-12.3, av. B = 7.8 µm, more or less 6-angular in frontal view, ellipsoid in side view, dark red-brown, with central to slightly eccentric germ pore. Basidia 18-50 x 9-13 µm, 4-spored, surrounded by 3-5 pseudoparaphyses. Pleurocystidia sparse or absent, 50-150 x 25-60 µm, vesiculose, ellipsoid or subcylindric. Cheilocystidia 30-80 x 15-50 µm, similar to pleurocystidia. Veil made up of up to 100 µm wide, (sub)globose elements. Clamp-connections present.

Habitat & distribution

  Solitary or a few together. On dung of horse and cow. Rather common.

Remarks

  Coprinus cothurnatus is a species close to C. niveus but differs in having hexagonal spores that are distinctly narrower than in C. niveus and the absence or sparsely presence of pleurocystidia.
  In collection C.B. Uljé 1005 a few 1-, 2- and 3-spored basidia have been found.