THE POLYPORACEAE OF WISCONSIN. 77 



The substance is very hard and thin, of a dull yellowish-cinnamon 

 color. The tubes usually are more than 2 mm. in length. A very thin 

 layer of the hymenophore is usually present between the layers. 



The whole plant is more or less pulvinate, smooth, with a rather 

 broad sterile margin, at least when young. The pores are usually 

 oblique with exceedingly small gaping mouths, in our forms cystidia 

 are not as plentiful as might be expected from the description. 



This species can readily be separated from its near allies by its re- 

 snpinate habit, and it is never as, thick as F. igniarius and F. nigricans. 

 Winter states that perhaps P. plicatus Persoon, and P. loricatus of the 

 same author, belong here. Our specimens agree well with no. Ill of 

 Shears' New York Fungi. 



Fomes ribis (Schum.) Fries. 



Horizontal, imbricated, coriaceous, rigid, flattened, almost even, vel- 

 vety, ferruginous then umber, margin acute ; pores short, minute naked, 

 and with the substance fulvous. 



Not common. My specimens were found on gooseberry bushes on 

 the University farm, near Madison. They are said to grow on cur- 

 rant bushes and rose bushes. 



This species is very much like F. conchatus. The pilei are, however, 

 less sulcate, less hard, more velvety when young, less resupinate ; color 

 of the substance slightly darker; the mouth of the pores more yellow- 

 ish-brown. The tubes are of the same size as in F. conchatus. The 

 surface is very uneven, but not much sulcate. One specimen is almost 

 ungulate. 



Syn. : Pyropolyporus Ribis (Schum.) Murrill 19, 30, p. 118. 

 Polyporus ribesius Persoon; 23, 2, p. 80. 



Fomes conchatus Fries. 



Thin, rigid, effuso-reflexed, the reflexed portion somewhat shell- 

 shaped; pileus dark brown, concentrically grooved, minutely silky, 

 margin acute; pores short, very minute, colored like the pileus; 

 spores 4x5 microns ; cytsida scanty, 15 30 x 9 microns. 



Fries says this species is ' ' closely allied to F. igniarius but is smaller 

 and thinner, closely concentrically sulcate, concave below, margin 

 acute. ' ' And Berkeley says : ' ' The principal distinction between this 

 and F. ribis appears to reside in the harder substance, and smoother 

 pileus. It varies in the degree in which the surface is grooved." 



