28 THE POLYPORACEAE OF WISCONSIN. 



Substance : Thin, waxy, becoming brittle when dry. 

 Pores: Small, very shallow, irregular giving the appearance of be- 

 ing arranged in concentric circles around various centers. 



Merulius aurantiacus Klotzsch (Plate I, fig. 4). 



Efl:uso-reflexed 2.5 to 4 cm. across, subcoriaceous, tough, dingy white, 

 yellowish or gray, coarsely tomentose, indistinctly zoned; hymenium 

 minutely rugulose, somewhat porose, orange. 



"Pileus 2.5 cm. broad; zones obsolete, hirsuto-tomentose. Nearly 

 allied to M. corium." Berk. 



Only two specimens were found on a fallen oak branch in Parfrey's 

 Glen. The largest specimen covered the stick for about 18 cm. The 

 pileus was reflexed to a width of one centimeter at its widest part. The 

 surface is nearly white without any suggestion of yellow — verging 

 perhaps more toward a grayish-white. The margin becoming in- 

 curved on drying, is smooth or somewhat wavy and not at all denticu- 

 late or radiate as in M. tremellosus. The tomentum on the pileus is 

 dense and coarse. It is well described by Berkeley (17, p. 190) when 

 he calls it "hirsuto-tomentose". The zones on the pileus form quite 

 conspicuous concentric ridges. 



The hymenium is of a reddish-orange verging toward ochraceous. 

 The substance seems to be leathery and tough. The pores are very 

 shallow, small and irregular. 



The hymenium appears to be thrown into circular ridges around 

 slightly raised centers which make it seem as though the pores are 

 arranged in concentric circles around these centers. This character- 

 istic is more striking in this species than in the following. 



M. aurantiacus is closely related to M. tremellosus and M. corium. 

 From the former it is distinguished by its tougher substance, small 

 pores, darker colored hymenium and smooth margin. From the latter 

 it differs in its thicker substance, darker colored hymenium, more re- 

 flexed pileus and the coarser tomentum. 



Merulius tremellosus Schrader. 



Kesupinate; margin becoming free and more or less reflexed, usu- 

 ally radiato-dentate, gelatinoso-cartilaginous ; hymenium variously ru- 

 gose and porose, whitish and subtranslucent, becoming tinged with 

 brown in the center; spores cylindrical, 4 by 1 micron. 



