POLYPORUS. 217 



107. P. mucidus Fr. — White becoming pale, effused, rather Polyporus. 

 thick, somewhat immersed, soft, the indetermi7iate circumference 

 flaxy. Pores medium-sized (seated on the crust formed of the 



mycelium), unequal and torn. 



It varies softer and firmer according to place, but is moderately persistent. 

 Much larger than P. molluscus, and not allied to it. 



On decayed fir. Penzance. 



Name— mucus, mucous. Mucid. From its substance. Fr. Hym. Eur. p. 

 577. B. & Br. ?i. 1967. — Pers. Syn. p. 546. 



108. P. vitreus Fr. — Whitish, somewhat hyaline, broadly and 

 unequally effused, rather thick, somewhat undulated, indeter- 

 minate, the thin villous margin shining white ; mycelium fornwig 

 a woody stroma, tough and separable. Pores very small, round, 

 long, obtuse, entire. 



The pores are straight or oblique according to situation. 



On dead wood, especially fir. Uncommon. Aug.-Nov. 



Distinguished by its distinct xylostromatoid substratum, which separates 

 easily from the matrix. B. & Br. Name — vitrtim, glass. Glassy. From 

 its shining appearance. Fr. Hym. Eur. p. 577. Syst. Myc. i. p. 381. Berk. 

 Out. p. 251. C. Hbk. n. 807. S. Mycol. Scot. n. 760. — Pers. Myc. Eur. 2. 

 p. 112. 



109. P. obducens Pers. — White, effused, incrusting, innate, 

 firm, wholly formed of very small, crowded, equal, distinctly 

 stratose pores, the annual strata pallid-tan. 



In the first year the plant resembles P. vulgaris, but in succeeding years it 

 becomes thick from the numberless strata (2 mm., 1 lin. thick) placed one 

 above another, altogether concrete with the mouldy wood which is pervaded 

 with the mycelium. In vertical places it puts forth rudimentary pileoli. 

 Allied to P. connatus. 



On rotten trunks. Rare. Bristol. 



Name— ob, and duco, to lead. Covering over. Probably from the strata 

 covering each other. Pers. Myc. Eur. 2. p. 104. — Fr. Hym. Eur. p. 577. 

 Berk. Out. p. 251. C. Hbk. n. 808. 



110. P. callosus Fr. — White, circumference similar, widely 

 effused, even, tough, entire, separable like soft leather. Pores 

 firm, round, equal, quite entire, obtuse. 



The pores are seated upon a skin, 2-4 mm. (1-2 lin.) thick, firm, but not 

 hard, everywhere porous. Annual and not stratose. 



On dead wood. Glamis, 1874. April. 



Spores pruniform, hyaline, 6 mk. Q. Name — callum, a hardened skin. 

 From the skin on which the pores are seated. Fr. Hym. Fur. /. 577. li. & 

 Br. 11. 1431. S. Mycol. Scot. n. 761. 



