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 [i thick usually, 

 brownish, darker and opaque near the substratum, the hyphae 

 densely interwoven, 3 [jl in diameter, somewhat colored; cystidia 

 incrusted, 25-40 X 4^-9 [x, distributed throughout the section; 

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

 sidium. 



Fructifications 2-5 X H-1 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: 

 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. 



