1926] 



BURT THELEPHORACEAE OF NORTH AMERICA. XV 205 



On decorticated pine limb completely decayed by a brittle, 

 brown rot. Maryland and Alabama. October. 



C. vescum looks like a thin, whitish or somewhat cinereous wash 

 in water color on the surface of the weathered pine limb. No 

 interwoven hyphal structure is visible under a lens, for the short 

 basal hyphae start out vertically from the substratum and ter- 

 minate in basidia packed closely together in the hymenium. 



Specimens examined: 

 Maryland: Takoma Park, C. L. Shear, 961. 

 Alabama: Montgomery, R. P. Burke, 476, type (in Mo. Bot. 



Gard. Herb., 57294). 



20. C. incanum Burt, n. sp. 



Type: in Burt Herb. 



Fructifications effused, very thin, closely adnate, not separable, 

 becoming pearl-gray to mineral-gray in the herbarium, even, 

 waxy, not cracked, the margin thinning out, indeterminate; in 

 section 20-75 [l thick, not colored, composed of densely inter- 

 woven, hyaline hyphae 23^-3 [l in diameter, rarely nodose-sep- 

 tate, not incrusted; no gloeocystidia; basidia simple, with 4 short, 

 blunt sterigmata; spores hyaline, even, about 33^-4 X lJ^-3 \l. 



Fructifications 4-8 cm. long, 1-2 cm. wide. 



On bark and wood of dead Acer and other frondose limbs. 

 Canada to North Carolina. October and November. 



C. incanum forms a thin, inseparable coating of mineral-gray 

 color over bark and wood of frondose species usually. The aspect 

 is so similar to that of common Peniophora cinerea that it is likely 

 to be passed by as the latter, if examination of microscopic 

 structure is not made. 



Specimens examined : 

 Canada: J. Macoun, 36; Ottawa, /. Macoun, 32, 34- 

 Vermont: Middlebury, E. A. Burt. 

 New York: Karner, H. D. House, comm. by N. Y. State Mus. 



Herb, (in Mo. Bot. Gard. Herb., 54384). " 

 New Jersey: Belleplain, C. L. Shear, 1249, type. 

 North Carolina: Chapel Hill, /. N. Couch, 4225, comm. by W. C. 



Coker, under the name C. ochraceo-niveum (in Mo. Bot. Gard. 



Herb., 57412). 



