1 66 AGARICUS. 



Pleurotus. on the mutilated side a thin margin whereby forms of this sort differ from 

 truly dimidiate species. 



* Veil forming a ring. Lepiotarii. 



* Veil none, gills sinuate or obtusely adnate. 



'* Veil none ; gills deeply decurrent ; stem distinct, somewhat vertical. 

 **** Veil none ; gills deeply decurrent ; pileus (seemingly) lateral, sessile 

 or extended behind into a short, oblique, stem-like base. 



II. Dimidiatae. Pileus definitely lateral, immarginate behind, not at the 

 first resupinate. 



III. Resupinati. Pileus at the first resupinate, with the gills meeting in an 

 excentric point, then reflexed, sessile. 



* Pileus Jleshy , uniform. 



** Pileus Jleshy, striate, with an tipper gelatinous stratum or "viscous 

 pellicle. 



*** Pileus membranaceous, not viscid. 



I. EXCENTRICI. 



* Veil forming a ring. 



359. A. corticatus Fr. Pileus 5-15 cent. (2-6 in.) broad, grey 

 then whitish, very compact, convex then flattened, somewhat disc- 

 shaped, horizontal, always entire, although excentric, when young 

 everywhere covered with dense grey down, which separates into 

 floccose scales on the whitish pileus when it is more flattened, 

 margin when young closely involute; flesh hard, shining white. 

 Stem 2.5-7.5 cent. (1-3 in.) long, 2.5 cent, (i in.) thick, stout, 

 solid, hard, rooted, more or less excentric, curved-ascending, some- 

 what equal, squamuloso-fibrillose, white. Ring silky-floccose, 

 moderately thick, white, ruptured in a torn manner, adhering 

 alike to the stem and the margin of the pileus, at length vanish- 

 ing. Gills deeply decurrent, anastomosing behind, also dichoto- 

 mously branched, somewhat distant, distinct, white, or becoming 

 yellow when old. 



Very compact and hard. Commonly solitary, sometimes caespitose. The 

 down with which the pileus is covered corresponds with the universal veil of 

 the Lepiottz. The flesh is not so thick as that of A. dryinus. The gills anas- 

 tomose behind like those of A. ostreatus, and vary in breadth according to 

 stature. 



On decayed ash, elm, &c. Uncommon. Sept.-Oct. 



Smell rather strong. Perhaps too closely allied to A. dryinus. B. & Br. 

 Spores 14 x 6 mk. W.G.S.; 12-14x4 mk. B. Name cortex, bark. From its 

 thick covering. Fr. Monogr. i. /. 236. Hym. Eur. p. 166. B. & Br. n. 

 995 (not Saund. & Sm.) C. Hbk. n. 109. Illust. PL 290. S. Mycol. Scot, 

 n. 209. 



360. A. dryinus Pers. Pileus 5 cent. (2 in.) broad, whitish, 

 variegated with spot-like scales which become fuscous, lateral, ob- 



