Abstract
The six species, Coriolellus sepium (Berk.) Murr., the type of Coriolellus Murr., C. serialis (Fr.) Murr., C. malicola (Berk. & Curt.) Murr., C. heteromorphus (Fr.) Bond. & Sing., C. variiformis (Peck) n. comb., and C. sinuosus (Fr.) n. comb., are similar in cultural characters and in the morphological characters of their sporophores and so constitute a homogeneous group. Detailed morphological and cultural descriptions of each of the species, together with the results of interfertility tests, are presented, along with a revised description of the genus, a description of its cultural characters, and diagnostic keys.