50 THE CHICAGO ACADEMY OF SCIENCES 



conspicuous feature in our plant, and are more numerous toward 

 the margin of the pileus. Plants 2.5 to 10 cm. broad. Spores 

 ellipsoid, 9 x 4 /x. 



Pleurotus atrocaeruleus Fr. 



Pileus dark azure blue, more rarely fuscous, resupinate then 

 reflexed, horizontal, obovate or reniform, villous, slightly wrinkled 

 when dry; flesh soft, the upper stratum toughly gelatinous, as 

 much as 4 mm. thick, fuscous-blackish, the lower thinner, whitish. 



Lamellae at first decurrent, then reaching the base, in groups 

 of 4 to 8, whitish, at length becoming light yellow. 



Spores 8 x 3 /x (W. G. S.) . Pileus 2.5 to 5 cm. broad. Sessile, 

 gregarious, somewhat imbricated, here and there emitting a plea- 

 sant odor. 

 . Var. griseus Pk. 



Pileus grayish or grayish-brown, clothed with rather coarse 

 pointed whitish or grayish hairs. 



Lamellae not broad. 



Spores elliptical, sometimes slightly curved, 7.5 x 4 /u. The 

 pileus is sometimes attached by the vertex, and the margin is 

 often beautifully crenately lobed or scalloped. (N. Y. Mus. 

 Rep. 44:35.) 



On bark of Hicoria ovata, woods, Glen Ellyn. July, 1902. 



Pileus dark grayish-brown with a bluish tint. Flesh in two 

 strata; the upper fuscous-blackish, less than a millimeter thick, 

 the lower whitish or pallid, 3 mm. thick. For the reason that the 

 relative thickness of the strata was so at variance with the de- 

 scription given above, specimens were sent to Professor Peck, 

 who refers them to his var. griseus. The spores in our plants are 

 very abundant, ellipsoid, 6 x 4 /x. 



Pleurotus applicatus Batsch. 



Pileus when young cup-shaped, orbicular, adnate behind, 

 villous at the base, commonly sessile, more or less pruinate; when 

 fuller grown more or less reflexed, more dimidiate, smooth or 

 slightly villous, slightly striate when damp. 



Lamellae few, rather thick, broad, distant, paler than the pil- 

 eus. 



Pileus 4 to 6 mm. broad, varying in color, cinereous or azure- 

 blue-blackish, dark or bluish-gray. 



On dead sticks and branches. Frequent. 



HYGROPHORUS. 



Hymenophore continuous with the stem, and descending un- 

 changed as a trama into the lamellae; lamellae acute at the edge, 

 clothed with a hymenium which turns into a waxy mass. Grow- 

 ing on the ground, fleshy, putrescent; pileus viscid or watery, 

 lamellae often branched. Spores white, globose. 



