The genus Hygrophorus is perhaps one of the most attractive among the genera of the Agaricales. It is surprising, therefore, that no full treatment of this genus in Europe has ever been published. Doubtless, European mycologists will be strongly stimulated by this American monograph in which 244 taxa are described and 116 illustrated by excellent black and white photographs. Of these 244 taxa, 41 are new to science: about 65 occur also in Europe. The European mycologist will be astonished by the strikingly high number of taxa in this monograph. The “Flore analytique” of Kühner & Romagnesi covers 80 species and varieties of Hygrophorus and there are 86 in the second edition of Moser’s “Die Röhrlinge, Blätter- und Bauchpilze”. Though the actual number of taxa of Hygrophorus in Europe may be much higher (Orton’s treatment of Hygrocybe in the “New check list of British Agarics and Boleti” is already an indication), it is not to be expected that Europe will have more than half as many species as North America.