1925] 



BURT THE THELEPHORACEAE OF NORTH AMERICA. XIV 349 



Fructifications effused, closely adnate, very thin, in small 

 patches becoming confluent, lurid, ashy in various shades as pale 

 drab-gray, pale mouse-gray, and cinnamon-drab, pruinose, waxy, 

 becoming cracked in drying; in section 50-100 [l thick usually, 

 brownish, darker and opaque near the substratum, the hyphae 

 densely interwoven, 3 jj. in diameter, somewhat colored; cystidia 

 incrusted, 25-40 X 43/-9 \l, distributed throughout the section; 

 spores hyaline, even, cylindric, 6-9 X 2-3 y., borne 4 to a ba- 

 sidium. 



Fructifications 2-5 X J^-l cm.; when scattered 2-5 mm. in 

 diameter. 



On fallen limbs of Alnus, Acer, Prunus, Pyrus, Quercus, and 

 most other frondose and coniferous species. Throughout North 

 America, West Indies, Europe, southern Africa, and Japan 

 probably cosmopolitan. Our commonest species. Throughout 

 the year. 



P. cinerea may be recognized by its resemblance to a thin coat 

 of ashy gray or slightly tinted paint on the bark of fallen limbs; 

 the substance of the sections is brownish when viewed with a 

 hand lens, and dark and opaque next the substratum under the 

 compound microscope. P. caesia, P. nuda, and P. violaceo-livida 

 must be cautiously separated from P. cinerea, for all are closely 

 related. 



Specimens examined: 

 >f Exsiccati: Berkeley, Brit. Fungi, 63, 64; Ellis, N. Am. Fungi, 21, 



under the name Corticium fumigatum, 610; Ell. & Ev., Fungi 



Col., 610, 805, under the name C. fumigatum; de Thiimen, 



Myc. Univ., 513, type distribution of C. fumigatum, 1206; 



Sydow, Myc. Germ., 205. 

 Sweden: L. Romell, 69, 70. 

 England: in Berkeley, Brit. Fungi, 63, 64; Kew Gardens, E. M. 



Wakefield (in Mo. Bot. Gard. Herb., 57121). 

 Germany: Brandenburg, in Sydow, Myc. Germ., 205; Berlin, 



P. Magnus (in N. Y. State Mus. Herb., and Mo. Bot. Gard. 



Herb., 55803). 

 Austria: Lengerich, Brinkmann, comm. by G. Bresadola; Tirol, 



three specimens, comm. by V. Litschauer. 

 Italy: Trento, G. Bresadola; Vallambrosa, Cavara, comm. by 



G. Bresadola. 



