LEUCOSPORI. 59 



110. A. arcuatus Bull. Pileus rufous-fuscous, becoming pale, Tricholom; 

 disc blackish, flattened, somewhat gibbous, soft, even, smooth, 



moist, discoid; margin thin, at the first inflexed; the flesh coloured. 

 Stem solid, firm, fibrilloso-squamulose, blackish downwards, 

 bulbous. Gills arcuato-adnate (decurrent with a tooth) and 

 arcuate, somewhat undulated, fragile, crowded, white. 



Gregarious. Pileus " almost viscid." Stem sometimes remarkably margin- 

 ato-bulbous. Sterb. t. 7. C. 



On grassy ground. St Andrews, 1877, &c. Oct.-Nov. 



Pileus 5-7.5 cent. (2-3 in.) broad. Stem about 4 cent. (t% in.) long, 12 

 mm. (Yz in.) thick. Name arcus, a bow. From the bow-shaped gills. 

 Bull. t. 443 figures with scaly stem. Fr. Hym. Eur. p. 70. Monogr. i. /. 

 86, partly. S. Mycol. Scot. n. 68. C. Illust. PI. 218. 



111. A. oreinus Fr. Pileus 2.5 cent, (i in.) broad, fttscous- 

 livid, fleshy, compact, convex, obtuse, even, smooth, the thin 

 margin not exceeding the gills ; flesh white. Stem scarcely 2.5 

 cent, (i in.) long, 4-8 mm. (2-4 lin.) thick, solid, equal, but 

 thickened at the base as with a small bulb and at length ochra- 

 ceous, white-squamulose at the apex, internally fibrillose. Gills 

 rounded then free, 4-6 mm. (2-3 lin.) broad, crowded, plane, 

 white. 



Solitary. Inodorous. It differs from A. humilis in not being hygrophan- 

 ous, and in the gills running out of equal breadth as far as the margin. The 

 uppermost and lowest in stature of the figures of Bull. t. 443 shows the form 

 sufficiently well. 



On heath and open ground. King's Cliffe. 



Name 6peu>os, hilly. From its being found on mountainous heaths. Fr. 

 Hym. Eur. p. 70. Monogr. i. p. 86. C. Illust. PI. 218. A. testudineus Pers. 

 Myc. Eur. p. 218. /. 23. /. i, 2. 



112. A. albus Schseff. Wholly white. Pileus 7.5-10 cent. 

 (3-4 in.) broad, truly fleshy, not compact, tough, convex then 

 flattened, becoming plane, obtuse, very dry, even, smooth, marginal 

 the first involute at length repand. Stem 7.5 cent. (3 in.) long, 

 12 mm. ()4 in.) and more thick, solid, attenuated upwards, some- 

 what bulbous, wholly fibrous, tougher externally, elastic, naked, 

 slightly mealy at the apex only under a lens. Gills emarginate, 

 somewhat crowded, distinct, when full grown 8 mm. (4 lin.) broad, 

 unchangeable. 



Stature very variable, sometimes very robust, sometimes moderately slender. 

 Odour weak or none, with an unpleasant acrid taste. Not hygrophanous ; 

 the pileus when dried becoming yellow often throughout or only at the disc. 

 All its forms (possibly including distinct species) are distinguished by their 



