July 1907] North American Species of Agaricaceae 151 



17. PSATHYRA NOLI-TANGERE Fries, Epicrisis, 

 1836. Fries, Icones, 138, Cooke, Illustr. 612. 



Pileus membranaceous, campanulate then expanded, radi- 

 ately striate, scaly around the margin, hygrophanous, pale umber, 

 becoming- pallid when dry. Stipe very fragile, nearly naked, 

 smooth at the apex, brownish. Lamellae broad, adnate, pale 

 brown ; spores elliptic-oblong, 12x5 mic. 



Gregarious ; growing among oak chips. Pacific Coast Cat. 

 Pileus 2-2.5 cm. in diameter; stipe 2-3 cm. long, 2 mm. thick. 

 An extremely fragile species. 



18. PSATHYRA PHOLIDOTA Montagne, Sylloge 

 Crypt. 1856. 



Pileus membranaceous, campanulate then expanded, scaly 

 in the center, the margin striatulate, violaceous. Stipe fistulous, 

 nearly equal, silky-fibrillose, concolorous with the pileus. La- 

 mellae rather narrow, attenuate-attached, purplish, at length 

 fuliginous; spores oblong, 12-13 mic. in length. 



Caespitose ; growing in grassy ground. Columbus, Ohio, 

 Sullivant. Pileus 1-3 cm. in diameter; stipe 4-8 cm. long, 2-3 

 mm. thick. The whole fungus violaceous, fragile and evanescent. 



19. PSATHYRA PLUMIGERA B. & C. Fungi Cub. 

 1867. 



Pileus convex, then plane, pubescent, striatulate, brown, 

 clothed with white scales ; the umbo obtuse. Stipe slender, fra- 

 gile, fistulous, subpellucid, white. Lamellae broad, adnexed, 

 brown. 



Growing on sticks in woods. Cuba, Wright. Pileus 12 mm. 

 in diameter ; stipe 3.5-4 cm. high, 2 mm. thick. 



20. PSATHYRA SENEX, Psilocybe senex Peck, 41 N. 

 Y. Rbp. 1887. 



Pileus thin hemispherical, obtuse, hygrophanous, dark brown 

 and striatulate when moist, pale cinereous and shining when dr}', 

 somewhat squamose with superficial subfasciculate whitish fibrils, 

 the margin appendiculate with the same. Stipe slender, hollow, 

 fragile, minutely floccose-pruinose, subpellucid, white. Lamellae 

 broad, subdistant, adnate, at first grayish, then brown or black- 

 ish-brown, the edge white ; spores brown, elliptic, 7-8 x 5 mic. 



Growing on decayed wood in woods. New York, Peck. 

 Pileus 1-2 cm. in diameter; stipe 4-7 cm. long, 2 mm. thick. 



