[Vor. 1 
92 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
of the pileus, 0.5-5 x 0.5-5 x 0.1-0.2 em., coriaceous, white to 
cinereous or almost black behind, villous, zonate, margin thin 
and acute; context white or pallid, fibrous, not more than 1 mm. 
thick; tubes less than 3 mm. long, the mouths white to bay and 
often violaceous toward the margin, averaging 2-3 to a mm., 
the dissepiments thin and soon lacerate and breaking up into 
teeth. 
Growing only on the wood of coniferous trees. In autumn. 
Rare. 
Closely related to P. pargamenus Fries, from which it is 
most easily separated by the habitat. The following spore 
dimensions are found in the literature: Karsten—“oblong 4-6 
х 1-3 и”; Murrill—“ globose, smooth, hyaline, 4.5-5.5 шіп diam- 
eter"; Bresadola—“ hyaline, cylindrical, subcurved, 6-7 x 2.5 и.” 
3. P. pargamenus Fries, Epicr. Syst. Myc. 480. 1838. 
Pileus sessile or effused-reflexed, imbricate, dimidiate or 
flabelliform, sometimes attached by an attenuate base, 1-7 
x 1-7 x 0.1-0.4 cm., coriaceous, whitish to cinereous or yellowish 
brown, villous, zonate, the zones sometimes differently colored, 
margin very thin, acute, broadly sterile below, often violaceous 
in color; context white or whitish, fibrous, very thin, less than 
1 mm. thick; tubes not more than 2.5 mm. long, the mouths 
whitish to bay and often violaceous toward the margin, angular, 
averaging 2-3 to a mm., the dissepiments thin and soon break- 
ing up into teeth; spores white, smooth, oblong, slightly curved, 
2-2.5 x 5-6.3 и. 
Growing on the wood of deciduous trees, especially of Quercus 
and Prunus. September to December. Common. 
Close to P. abietinus Dicks. ex Fries, but usually found on 
dead wood of deciduous trees. Well represented by Hard 
(Mushrooms f. 345) as P. pergamenus. 
4. P. hirsutulus Schw. Trans. Am. Phil. Soe. II. 4: 156. 
1832. 
Pileus sessile or effused-reflexed, often imbricate, dimidiate, 
0.5-2 x 0.5-2.7 x 0.1-0.2 cm., coriaceous, gray or cinereous to 
yellowish brown, hirsute or strigose, azonate or with 2-3 
colored zones, margin thin and acute, usually sterile below; 
context white or whitish, membranous, less than 1 mm. thick; 
tubes less than 2 mm. long, mouths whitish to yellowish, rarely 
