CLASSIFICATION 383 



Known by the fibrillosc, radiating edge ; walls of pores very thin 

 and often torn. 



On dead wood, heaps of leaves, etc. 



P. vulgaris. — Forming patches 6-12 in. across, flesh almost 

 obsolete, consisting almost entirely of minute roundish pores i-i line 

 deep. 



On dead wood and branches. 



P. medulla-panis. — Forming patches 2-4 in. across and about 

 2 lines thick, edge naked, determinate, flesh obsolete, consisting 

 almost entirely of medium-sized, roundish pores. 



Rigid and separable when dry. 



On rotten wood and branches. 



P. vitrea. — Forming irregular patches up to 2 in. across, whitish, 

 subhyaline, separable, indeterminate, edge downy, flesh below the 

 pores distinct ; pores minute, entire, about i-| lines long, straight 

 or oblique. 



Readily separable from the wood. 



On rotten wood, especially fir. 



P. hihernica. — Appearing as small circular spots which soon grow 

 into each other, forming very irregular patches, white, inseparable, 

 edge downy, radiating ; pores small, polygonal, short. 



On pine wood. 



P. gordonensis. — Forming patches 1-2 in. across, thin, separable, 

 persistently white, edge fibrillose ; pores minute, unequal, angular, 

 toothed at the edge. 



Differs from P. hihernica in being separable, and from P. radula 

 and P. vaporaria in the smaller and more regularly angular pores. 



On fir poles. 



P. blephari stoma. — Thin, snow-white, patches 1-2 in. across ; 

 pores very shallow, small, edges toothed. 



On dead wood, branches, etc. 



P. farinella. — Forming irregular, thin, pulverulent patches 

 about I in. across ; pores unequal, \\'avy. 



Very thin and almost disappearing when touched. 



On dead beech wood, etc. 



P. reticulata. — Forming roundish, thin white patches that soon 

 disappear ; pores resembling a \exy shallow net\\ork, rather large. 



On rotten wood. 



P. vaillantii. — Patches very thin and fibrous, \\ith thread-like, 

 spreading mycehum ; pores rather large, occurring in scattered 

 clusters. 



Known l)y the spreading white, thread-like m3'celium connect- 

 ing the patches of membrane producing the pores. Becoming 

 tinged brown. 



On dead wood. 



