THE POLYPORACEAE OF WISCONSIN. 27 



§2. Leptospori. Hymenium naked or lightly powdered with the 

 white spores. 



Merulius aureus Pr. 



Effuse, thin, membranaceous, adherent, golden-yellow, margin thin, 

 villous, of the same color ; hymenium plicate-porose, gyrose ; spores 

 globose or subglobose, yellowish, S microns in diameter. 



Several well developed specimens were found at Bangor which were 

 identified by Bresadola as belonging to this species. It may well be 

 more abundant in the state than this would indicate. 



Merulius corium (Pers.) Fi'ies (Plate I, fig. 3). 



Resupinate effused, soft, sub-papyraceous at length reflexed with the 

 margin free, villose, beneath white. Hymenium reticulate-porose 

 flesh-colored becoming paler; spores oblong-lanceolate, hyaline 10 x 3 

 microns. 



Macbride (15, p. 4) says that this species when fresh is noticeable 

 for its delicate tints and soft velvety snow white margin. Massee says 

 it is very variable, but known by its white, silky pileus and the reticu- 

 lato-porose, ochraceous hymenium. 



This species seems to be rare in Wisconsin. Our only specimens 

 were collected at Bangor, LaCrosse Co., in October, 1905. The speci- 

 mens grew on the under side of an alder branch lying on the ground. 

 The stick was covered for a distance of about 30 cm., the fungus aver- 

 aging in width about 2.25 cm., and .5 mm. in thickness when dry. The 

 pileus is reflexed about 5 mm. 



The pileus and margin are white or whitish, but the hymenium is 

 pale ochraceous with more or less of a rosy tinge. On drying the rosy 

 tinge disappears, leaving it a pale straw color. 



When fresh the substance is soft and waxy, but on drying it be- 

 comes brittle and papyraceous. 



The pores are very shallow near the margin but are deeper in the 

 center. They seem to be arranged more or less in concentric circles, 

 around rather definite centers. This characteristic is shown quite well 

 in the figure. This species seems to be closely related to M. aurantiacus 

 Klotsch., differing only in the paler color of the hymenium, the less 

 reflexed pileus and the thinner substance. 



Identification is based on the following characteristics: 



Color: Whitish pileus and pale ochraceous hymenium tinged with 

 rose. 



