Spore-print: black.
Spores: long, very dark brown under the microscope, broadly lemon-shaped with large germ-pore, smooth and 14-15 × 9-10 µm in size (14-19 × 8-10 × 10-12 µm).
Facial cystidia: absent.
Marginal cystidia: numerous, cylindrical, flexuous and hyaline.
General Information: P. sphinctrinus is recognised by the overall grey colouration and very distinct white fringe to the cap-margin.
P. campanulatus (Fries) Quélet which is said to be common is in fact infrequent and many records really refer to P. sphinctrinus. The word semiovatus means half ovate and refers to the shape of the cap in P. semiovatus. Sphinctrinus means banded, referring to the zoned cap of the fungus when it is partially dry.
Illustrations: P. semiovatus—LH 145; WD 773. P. sphinctrinus—NB 415; WD 781.
Coprinus cinereus (Fries) S. F. Gray Dung-heap ink-cap
Cap: width 20-40 mm. Stem: width 4-8 mm; length 50-100 mm.
Description: