THE POLYPORACEAE OF WISCONSIN. 29 



On wood. From 2.5 to 7.5 cm. across remaining pale when growing 

 in the shade. Margin sometimes tinged with rose, radiating when well 

 developed. 



Common in Wisconsin on the underside of old logs, and charred 

 stumps. Specimens were found near Madison, Blue Mounds, Hori- 

 con, Dodge County, Hazelhurst, Oneida County, Crandon, Forest 

 County, Sparta, Monroe County, Bangor, La Crosse County, and Mil- 

 waukee. 



The pileus of the older specimens usually becomes more or less re- 

 flexed especially if they grow on the side of a log. The pileus is then 

 snow-white above, except at the margin covered with a soft tomentum 

 when dry. The margin is thin, fimbriate, toothed or radiate, red, turn- 

 ing reddish-brown. The underside is made up of shallow irregular 

 pores formed by the anastomosing folds of the subgelatinous red to 

 reddish-brown hymenium. The pores are usually arranged radially. 



When dry the substance is quite leathery or more brittle in old 

 specimens. Young specimens are quite thin — often 0.5 mm. to 1 mm. 

 in thickness. These are quite gelatinous, subtranslucent, more or less 

 orbicular; the margin very thin, soon becoming free and more or less 

 reflexed. 



The hymenial layer appears to consist of fine filaments, embedded 

 in a gelatinous substance, not much interwoven but running more or 

 less parallel with each other, bending downwards into the folds which 

 form the pores. The filaments seem to enter the hymenium from the 

 pileus in strands or bundles. In this respect it differs from Gleoporus 

 conchoides, the young of which it resembles somewhat in appearance 

 and consistency. In the latter the pileus passes more gradually into 

 the denser hymenium which, however, is also made up of more or less 

 parallel fibres embedded in a jelly-like substance when young. Mature 

 specimens of G. conchoides are of course at once distinguishable by the 

 minute, elongated, round tubes. 



M. rubellus, a near relative, is never resupinate but always sessile, 

 more tenacious, less tomentose. 



The larger specimens found measured from 4 to 8 cm. in width, re- 

 flexed to about 4 cm. The pileus is about 3 to 4 mm. thick, the pores 

 scarcely 0.5 mm. in depth. 



Following are the distinctive characteristics : 



Color: White above when reflexed; pale rose, red or reddish-brown 

 underneath. 



Hymenium : Gelatinous or waxy, soft, translucent when young. 



Pores : Irregular shallow, made by the folds of the hymenium. 



Syn. Xylomyzon tremellosum Pers. ; 23, 2, p. 30. 



