ANALYTICAL KEYS. 309 



10 Margin of pileus at first involute, pileus flat or nearly so, 

 somewhat fleshy (some plants rather tough and tending 

 toward the consistency of Marasmius). . Collybia. . 92 

 Margin of the pileus at first straight, pileus slightly bell- 

 shaped, thin . Mycena. . 93 



Gills usually free, pileus deeply plicate so that the gills are 

 split where they are attached to the pileus, pileus mem- 



branaceous, very tender but not diffluent. Hiatula. 



11 Plants where bruised exuding a milky or colored juice. . . Lactarius. . 1 14 



Plants not exuding a juice where bruised Russula. . 125 



12 Gills decurrent, dichotomous, edge blunt Cantharellus. 128 



Gills not decurrent, plants parastic on other mushrooms. Nyctalis. 



13 Edge of gills not split into two lamina? 14 



Edge of gills split into two lamina? and revolute Schizophyllum. 136 



14 Plants leathery, either fleshy, membraneous, or gelat- 

 inous 1 5 



Plants corky or woody (placed by some in Polyporacea?). Lenzites. 

 IS Stipe separate from the pileus (hymenophore), easily 



separating 16 



Stipe continuous with hymenophore. . 17 



16 Plants tough and fleshy, membranaceous or leathery. . . Marasmius. . 130 



Plants gelatinous and leathery. ... . Heliomyces. 



17 Edge of the gills acute 18 



Edge of the gills obtuse. . . 19 



18 Edge of gills usually serrate . Lentinus. 134 



Edge of gills entire . Panus. . .134 



19 Gills dichotomous. . . Xerotus. 



Gills fold-like, irregular Trogia. ... 137 



There are only a few rare species of Hiatula, Nyctalis, Heliomyces and Xero- 

 tus in the United States. None are here described. 



THE OCHRE-SPORED AGARICS. 



(The spores are yellowish brown or rusty brown.) 



Gills not separating readily from the pileus i 



Gills sometimes separating readily from the pileus, forked 

 or anastomosing at the base, or connected with vein- 

 like reticulations Paxillus. 165 



1 Universal veil not arachnoid (i. e., not cobwebby) 2 



Universal veil arachnoid, distinct from the cuticle of the 



pileus, gills powdery from the spores Cortinarius. . 161 



2 Stipe central .3 



Stipe eccentric or none .... Crepidotus. . 159 



3 Volva or annulus present on stipe .4 



Volva and annulus wanting 5 



4 Stipe with an annulus Pholiota. 150 



Stipe with a volva. Locellina (not reported in U. S.). . . 



5 Gills free from the stem Pluteolus. 



Gills attached 6 



6 Gills not dissolving nor becoming powdery. . 



