11 E FORT OF THE B OTA X 1ST. 93 



curved margin separate this from the preceding species. (Plate 

 2, figures 1-5.) 



*78. Agaricus semiorbicularis Bull. 



Pileus thin, fleshy, hemispherical, at length expanded, 

 smooth, subviscid, dull yellow ; lamellae close, broad, attached, 

 at length dark ferruginous ; stipe slender, equal, firm, stuffed 

 with a distinct whitish pith, yellowish. 



Height 1-2', breadth of pileus 6"- 12". 



Fields and manured grounds. West Albany. June. 



It is sometimes csespitose. The pileus sometimes cracks 

 into areas. It has an oily flavor, resembling that of beech 

 nuts. 



Subgenus — Galera. 



Stem externally subcartilaginous ; pileus more or less cam- 

 panulate ; margin straight. — Berk. Outl. 



The spores are generally bright ferruginous. The pileus is 

 thin, obtusely conical or bell-shaped, and the stem is hollow, 

 rather long and slender, so that in aspect the species correspond 

 to those of the subgenus Mycena in the first series. All of our 

 species, so far as known, are hygrophanous. 



Synopsis of the Species. 



Pileus at length expanded . . „. a. 



a. Plant growing in fields or on dung ; pileus not umbonate 79. 



a. Plant growing in marshes ; pileus generally umbonate %'Z. 



Pileus Hot expanded b. 



b. Plant growing in fields or groves c. 



c. Pileus dark ferruginous 80. 



c. Pileus pale yellow 81. 



b. Plant growing in woods among moss 83. 



79. Agaricus lateritius Fr. 



Pileus thin, submembranaceous, fragile, conical, at length 

 expanded, closely and finely striate on the margin, grayish- 

 yellow,, darker when moist; lamellae close, narrow, nearly or 

 quite free, yellow-ferruginous ; stipe long, white, fragile, 

 easily splitting, pruinose or farinaceous above, slightly taper- 

 ing upward. 



Height 3-4', breadth of pileus, 1-2'. 



On dung heaps. West Albany. June. 



Sometimes there is a slight pinkish tinge to the pileus and 

 stem. 



