90 THE CHICAGO ACADEMY OF SCIENCES 



Agaricus campestris L. 



Pileus fleshy, varying white and rufescent, lens-shaped- 

 convex then flattened, obtuse, dry, sometimes silky-even, some- 

 times squamulose; flesh thick and soft, becoming reddish or 

 sometimes fuscous. 



Lamellae free, approximate, ventricose, equally attenuated at 

 both ends, crowded, often deliquescent, pallid flesh-color, at length 

 umber-fuscous. 



Stem stuffed, firm, short, bulbous when young, then somewhat 

 equal, even or squamulose, white; ring medial, spreading or re- 

 flexed, torn, often deciduous and sometimes in the form of a 

 cortina. 



On the ground in pastures, spring and autumn. Throughout 

 our district. Usually infrequent, but occasionally locally abund- 

 ant in autumn after rains. Edible. The common mushroom of 

 the shops. The annual product of the Chicago mushroom beds 

 is said to be from sixty to seventy-five tons, of which fifty tons 

 are consumed here, the remainder being shipped to nearby cities. 



Agaricus silvaticus Schaeff. 



Pileus somewhat ferruginous, scales rufescent or becoming 

 fuscous, thinly fleshy, oval then campanulate and flattened, 

 somewhat umbonate, the whole surface floccose, torn into squam- 

 ules, the disk however often remaining continuous, and at length 

 denuded of scales, margin often rimosely incised; flesh thin, 

 fragile, white or rufescent. 



Lamellae free, ventricose, equally attenuated at both ends, 

 thin, arid, reddish then cinnamon-fuscous or umber-fuscous. 



Stem slender, at first stuffed with a cylindrical white pith, 

 then hollow, equal, dingy white, fibrillose below the ring and even 

 above it, smooth; ring distant, simple, floccose beneath, some- 

 times wide but thin and membranous, sometimes narrow, in- 

 complete and fugacious. 



Pileus 7.5 cm. broad; stem 7.5 to 9 cm. long, about a cm. 

 thick. 



Woods, Lisle. August. Laxly gregarious. Lamellae at firs,t 

 rosy-pink, then reddish-brown, finally brownish-black. Spores 

 broadly ellipsoidal, 5 x 3 p. 



Agaricus silvicola Vitt. 



Pileus convex or subcampanulate, smooth, shining white. 



Lamellae close, free, acute behind, whitish then slowly becom- 

 ing fuscous. 



Stem stuffed, elongated, bulbous, white; annulus simple. 



Pileus 7.5 to 15 cm. broad; stem 10 to 15 cm. long, 8 to 15 

 mm. thick; spores 6 to 8 x 4 to 5 /x. 



Woods, Glencoe. August. Infrequent. 



