Thirty-nine species are recognized in the lichen genera Calicium Pers., Chaenotheca (Th.Fr.) Th.Fr., Cyphelium Ach., Microcalicium Vain. emend. Tibell, Sclerophora Chevall., and Thelomma Massa!. emend Tibell in Norway. The genus Cybebe is reduced to synonymy with Chaenotheca, and the new combinations Chaenotheca gracilenta (Ach.) Mattsson & Middelborg and Sclerophora coniophaea (Norm.) Mattsson & Middelborg are proposed. Three families are recognized, the Caliciaceae, the Coniocybaceae, and the Microcaliciaceae. The chemistry is described, and a number of unidentified secondary substances are characterized by their Rf values. The ecology and distribution of the species are described. Keys are given to the genera and species, and distribution maps for Norway are provided. Calicium adaequatum Nyl., Calicium adspersum Pers., Calicium corynellum Ach., Calicium parvum Tibell, Chaenotheca carthusiae (Harm.) Lett., and Microcalicium ahlneri Tibell are reported new to Norway.
