4. Thelephoraceae : Plants somewhat corky or membranaceous, more or less 



expanded ; hymenium on the under surface (upper surface sterile), or on 

 the outer or exposed surface when the plant is spread over the substratum 

 (margin may then sometimes be free, but upper surface, i. e., that toward 

 the substratum, sterile). (Minute slender spines are sometimes inter- 

 mngled with the elements of the hymenium, and should not be mistaken 

 for the stouter spinous processes of the Hydnaceae). 



5. Clavariaceae : Plants more or less fleshy, upright (never spread over the 



surface of the substratum), simple or branched. Hymenium covering 

 both sides and the upper surface. 



AA) Tremellineae : Plants gelatinous or subgelatinous ; basidia forked or longi- 

 tudinally or transversely divided ; or if continuous then globose, or 

 bearing numerous spores ; or if the plant is leathery, membranous, or 

 floccose then basidia as described. Hymenium covering the entire 

 free surface or confined to one portion ; smooth, gyrose, folded or lobed; 

 or hymenium lamellate, porous, reticulate or toothed forms which are 

 gelatinous and provided with continuous basidia may be sought here. 



Fam. I, Agaricaceae. 



Pileus more or less expanded, convex, bell-shaped ; Stipe central or nearly 

 so ; or the point of attachment lateral, when the stipe may be short or the 

 pileus sessile and shelving. Fruiting surface usually on the under side and 

 exposed toward the earth, lamellate, or prominently folded or veined. Lamellae 

 or gills radiating from the point of attachment of the pileus with the stipe or 

 with the substratum in the sessile forms ; lamellae simple or branched, rarely 

 anastomosing behind, clothed externally on both surfaces with the basidia each 

 of which bears four spores (rarely two), cystidia often present. 



Key to the genera. 



SECtlON 1. LEUCOSPORAE Fr. Spores white or whitish, or faintly yellow 

 or roseate. Plants soft or tough. 



Series l. Haplophyllae. Edge of gills entire, not split or grooved. 



Subsection l. Molles. Plants soft, fleshy or nearly so, usually soon decaying ; 



dried plants do not revive well when moistened. 

 A) Gills acute on the edge, not pliciform or folded. 



a) Trama of the pileus of inte>-woven threads, not vesiculose. 

 b) Gills thin (not broadened toward the pileus), substance of the pileus not 

 passing into the trama of the gills unchanged, 

 c) Centrales. Stipe central or subcentral. 

 d) Stipe fleshy ; hymenophore separate from the stipe ; gills usually 

 free. 



AMANITA. Stipe with a distinct volva and annulus. 

 AMANITOPSIS, Volva present, annulus wanting. 

 I-EPIOTA. Volva wanting, annulus present. 



