20 THE CHICAGO ACADEMY OF SCIENCES 



8 Trama vesciculose, substance of pileus rigid- 



fragile 9 



9 Lamellae with a milky juice ._ Lactarius. 



Lamellae juiceless, plant rigid and brittle. . .Russula. 

 Lamellae waxy when mature Hygrophorus. 



10 Stem lateral or wanting Pleurotus. 



11 Stem central; plants tough, fleshy or leathery Marasmius. 

 Stem lateral or wanting 12 



12 Lamellae serrate or eroded on the edge Lentinus. 



Lamellae entire Panus. 



Lamellae anastomosing Lenzites. 



Lamellae split longitudinally, the laminae 



revolute Schizophyllum. 



SPORES ROSY, ETC. 



13 Stem central 14 



Stem lateral, eccentric or none . . Claudopus. 



14 Stem fleshy, separating easily from the pileus 15 



15 With volva Volvaria. 



Without a volva Pluteus. 



16 Stem fleshy or fleshy-fibrous, confluent with 



the pileus 17 



17 Lamellae adnate or sinuate Entoloma. 



Lamellae decurrent Clitopilus. 



18 Stem cartilaginous: 



Lamellae slightly attached Leptonia. 



Lamellae decurrent Eccilia. 



SPORES OCHRACEOUS, ETC. 



19 Stem central 20 



Stem lateral or none Crepidotus. 



20 Stem fleshy, plant with an arachnoid univer- 



sal veil Cortinarius. 



Stem fleshy, without an arachnoid veil 21 



Stem cartilaginous 24 



21 Lamellae anastomosing. . .* Paxillus. 



Lamellae not anastomosing 22 



With an annulus Pholiota. 



Without an annulus 23 



23 Lamellae subsinuate, surface of pileus silky 



or fibrillose Inocybe. 



Lamellae subsinuate, surface of pileus glab- 

 rous, viscid Hebeloma. 



Lamellae adnate or decurrent Flammula. 



24 Pileus fleshy, margin inflexed Naucoria. 



Pileus slightly fleshy, viscid, margin straight. . Pluteolus. 

 Pileus membranaceous, striate, margin 



straight Galera. 



SPORES BLACK, ETC. 



25 Spores with a brownish or purplish tint 26 



Spores black or nearly so 29 



