KEY TO GENERA l ^ 



Stem simple. 



With a volva 2I ACETABULARIA. 



Without a volva. 



Gills adhering to the hymenophore and 

 sinuate. 



Cuticle fibrillose or silky 25 INOCYBE 



Cuticle smooth, viscid '/. 2 6 HEBELOMA. 



Gills separating from the hymenophore and 



decurrent, stem sometimes obsolete 46 PAXILLUS. 



(Group 2. Tapinia.) 



Gills decurrent 3 o TUBARIA. 



Gills not decurrent. 



Margin of pileus at first incurved 28 NAUCORI A. 



Margin of pileus always straight. 



Hymenophore free from the stem 23 PLUTEOLUS. 



Hymenophore confluent with the stem... 29 GALERA. 



Stem lateral or absent 3 ! CREPIDOTUS. 



IV. Spores purple, brownish-purple, dark purple, or dark 



brown. 



A. Stem without cartilaginous bark. 

 Hymenophore distinct from the fleshy stem. 



Stem volvate 32 CHITONIA. 



Stem without a volva. 



Stem annulate 33 PSALLIOTA. 



Stem simple 34 PILOSACE. 



Hymenophore confluent with the stem. 



Veil normally ring-like on the stem 35 STROPHARIA. 



Veil normally fibrillose and adhering to the 



margin of the pileus 36 HYPHOLOMA. 



B. Stem with cartilaginous bark. 



Margin of pileus at first incurved 37 PSILOCYBE. 



Margin of pileus at first straight 38 PSATHYRA. 



V. Spores black or nearly so. 



Gills deliquescent 42 COPRINUS. 



Gills not deliquescent. 



Gills decurrent 45 GOMPHIDIUS. 



Gills not decurrent. 



Stem annulate 39 ANELLARIA. 



Stem simple 40 PAN^EOLUS. 



Pileus striate 41 PSATHYRELLA. 



Genera 1-41 represent the genus Agaricus as understood by 

 Fries who regarded the modern genera as of subgeneric rank only. 

 They include species 1-920, and are arranged in five series defined 

 by the colour of the spores as illustrated in the five diagrams 

 (Plates I.-V.). 



The genera which are marked in corresponding positions on the 

 different diagrams are structurally identical; the only difference is 

 in the colour of the spores. For instance, Amanitopsis, on the first 

 diagram, has white spores ; it corresponds in structure with Volvaria, 

 with pink spores, on the second diagram, with Acetabularia, with 

 brown spores, on the third, and with Chitonia, with purple spores, on 

 the fourth. There is no genus structurally identical with Amanitopsis 



