110 THE CHICAGO ACADEMY OF SCIENCES 



tomentum or hairiness, then gray, finally blackish, in old speci- 

 mens, concentrically sulcate, rimose, substance obscurely zonate, 

 whitish, then isabelline or pale-tawny, the margin obtuse. 



Pores stratose, plane or subconvex, small, nearly equal, 

 subrotund, the dissepiments obtuse, entire, whitish. 



Spores white, broadly elliptical, 7.5 to 9 x 6 to 7.5 /i; pileus 

 5 to 10 cm. long, 2.5 to 3.5 cm. broad. On living trees of white 

 ash. 



Near the base of trunks of Fraxinus, River Forest (Harper); 

 and Glen Ellyn. 



Prof. MacBride suggests (Bull. Lab. Nat. Hist. la. 3 3 : 20) 

 that this is probably a synonym of F. ulmarius. Our specimens 

 are too imperfect to "warrant a conclusion. They are referred 

 here provisionally, as they were found growing upon ash. 



Fomes scutellatus Schw. 



Small, rarely dimidiate, 1 to 2.5 cm. broad, wholly affixed by 

 the base, hence scutellate, orbicular or unequally undulate; 

 pileus very hard, blackish-fuscous, rugose-sulcate, zoned, plicate, 

 glabrous; margin white, somewhat prominent. 



Hymenium concave, white, pulverulent. Pores minute, 

 rhomboidal. at length blackish, tubes whitish-cinereous; context 

 fulvous or cinnamon. 



Riverside. October, 1902. Harper. 

 Fomes Ribis Fr. 



Pilei horizontal, imbricated, coriaceous, rigid, flattened, almost 

 even, velvety, ferruginous then umber, margin acute. 



Pores short, minute, and with the thin flesh fulvous. Peren- 

 nial, stratose; pileus often indistinctly zoned. 



At the base of currant bushes in a garden at Wheaton, 189S 

 to 1908. The fungus often wholly encircles the stems and super- 

 ficial roots of the host. The new growth appears as an elevated 

 proliferous zone at the margin of the pileus of the preceding year, 

 and is of a bright ochraceous color, standing out in sharp contra-t 

 to the umber-colored zone of the last year, while this older band 

 or zone contrasts in turn with the still darker or blackish one 

 preceding it. The pores, however, are continuous over the whole 

 under surface of the plant. The pilei are irregular in shape, 

 3 to 6 cm. broad; pores about 2 mm. long. 



POLYPORUS. 



Pileus fleshy, at first soft, becoming indurated, zoneless with- 

 out, but with the context zonate or radiate-fibrous; hymeno- 

 phore descending as a trama between the pores, which are there- 

 fore inseparable from the context and from each other. 



Plants stipitate, sessile or lateral, lignicolous or terrestrial. 



