Contents: Introduction. History. A proposed synopsis. I. General considerations: 1. Characters. 2. Ecological considerations. 3. Geographic consideration. 4. Seasonal occurrence. 5. Phylogeny and classification. 6. Materials studied. 7. Doubtful and excluded species. II. Classification of Hygrophorus fries: 1. Subgenus pseudohygrophorus. 2. Subgenus Hygrophorus. 3. Section Camarophyllus. 4. Subsecton Camarophyllopsis. 5. Subsection Microspori.  6. Section Hygrotrama. 7. Section Hygrocybe. 8. Subsection  Hygrocybe. 9. Subsection Punicei. 10. Subsection Psittacini. 11. Section Hygroaster. 12. Section Amylohygrocybe. 13. Section Hygrophorus.  14. Subsection Hygrophorus. 15. Subsection Camarophylli. Bibliography. Index.