1926] 



BURT THELEPHORACEAE OP NORTH AMERICA. XV 191 



face, somewhat cracked, the margin and subiculum floccose to 

 fibrillose and sometimes hirsute; in section 200-1000 ji thick, 

 with the hyphae suberect, loosely interwoven, thick-walled, 

 4-5 [l in diameter, nodose-septate; no gloeocystidia ; spores 

 hyaline, even, 6-10 X 5-6 p. 



Fructifications 3-10 cm. long, 2-3 cm. wide. 

 On bark of living and dead Salix and Alnus usually, but also on 

 Betula, Acer, Tilia, Populus, and Pinus. In Europe and from 

 Canada to Massachusetts and westward to Washington and 

 Arizona, and in Texas. July to March. Uncommon. 



C. bombycinum is a thick species with description somewhat 

 suggestive of C. cremoricolor, but it does not crack radially, and 

 tend to brown color like the latter, is more spongy and with more 

 pelliculose hymenium and with a broader, thicker, and very 

 conspicuous margin, and favors Salix as a substratum. 



Specimens examined: 

 Exsiccati: Brinkmann, Westfalische Pilze, 11; Jaczewski, Fungi 

 Rossiae, 232, under the name Hypochnus Sambuci; Romell, 

 Fungi Scand., 35, under the name Corticium serum. 

 Norway: Saltd, Sommerfelt, fragment of type comm. by L. Ro- 

 mell. 

 Sweden: Stockholm, L. Romell, 63, 64, 65, 201, 344, and in Romell, 

 Fungi Scand., 35; Upsala, L. Romell, two unnumbered speci- 

 mens. 

 Russia : in Jaczewski, Fungi Rossiae, 232. 

 Germany: Lengerich, in Brinkmann, Westfalische Pilze, 11. 

 Austria: Feldkirch, Rick, comm. by Bresadola. 

 Canada: J. Macoun, 56, 60, in part, 157; Lower St. Lawrence 



Valley, J. Macoun, 30. 

 Ontario: Port Credit and Toronto, J. H. Fault, 655 and 380, 



respectively (in Mo. Bot. Gard. Herb., 44943, 44948). 

 Vermont: Middlebury, E. A. Burt. 



Massachusetts : on beams in cotton mill, R. J. Blair, 248, in part, 

 comm. by L. O. Overholts, 3812a (in Mo. Bot. Gard. Herb., 

 54995). 

 New York: Alcove, C. L. Shear, 1317; Clear Water, G. F. 

 Atkinson, 5050; East Gal way, E. A. Burt; Hudson Falls, S. H. 

 Burnham, 14 (in Mo. Bot. Gard. Herb., 44007) ; Kenwood, S. H. 



