210 



Mycologia 



This attractive species is usually distinguished from A. arvensis 

 by its smaller size and more slender shape. The abruptly bulbous 

 stipe often seen in American specimens can hardly be considered a 

 specific character; the same variation occurs in A. subrufescens, 

 for example. There are many specimens at Albany from the 

 eastern United States and I found it in several places on the Pacific 

 coast, but never abundant. 



15. Agaricus micromegethus Peck, Bull. N. Y. State Mus. 116: 



44. 1907 



Agaricus pusillus Peck, Ann. Rep. N. Y. State Mus. 54: 152. 

 1 90 1 ; not A. pusillus Schaeff. 1774. 



Pileus fleshy but thin, convex, becoming plane, sometimes slightly 

 depressed at the center, solitary or cespitose, 1-5 cm. broad; sur- 

 face dry, silky-fibrillose or fibrillose-squamulose, grayish-brown, 

 darker or brown on the disk, often with yellowish or ferruginous 

 stains ; context fragile, white or whitish, not changing color when 

 wounded, with taste and odor of almonds ; lamellae thin, crowded, 

 free, grayish, soon pinkish, finally brown ; spores broadly ellipsoid 

 or subglobose, 5x4^; stipe equal or slightly tapering upward, 

 sometimes bulbous, stuffed or hollow, slightly fibrillose, white, 1- 

 2.5 cm. long, 2-6 mm. thick; annulus slight, often evanescent. 



Type locality : Detroit, Michigan. 



Habitat : In various kinds of soil in shaded or exposed places. 



Distribution : New England to Tennessee, and west to Michi- 

 gan and Texas. 



Illustration: Bull. N. Y. State Mus. 116: pi. 107, f. 1-6. 



Type collected by Dr. R. H. Stevens. Other specimens are at 

 Albany from Mackintosh, Morris, DeRouville, etc. I collected it 

 on the Upper St. Regis ; at Un'aka Springs, Tennessee ; and at 

 Blacksburg, Virginia. There are specimens here also from New 

 Jersey and Texas. The plant is not always small, but often about 

 the size of the ordinary field mushroom. This is expressed in 

 Peck's later name. Specimens from Delhi, New York, collected 

 by Sherwood, are set aside by Peck as a variety. 



