236 
THIRTEENTH REPORT. 
4. Fruit-body orange, dimidiate, rather soft, fibrous-tomentose : 
Polystictus aurantiacus Pk. 
4. Fruit-body not orange (5) 
5. Tubes soon breaking up into Irpex-like teeth: (6) 
5. Tubes entire, unless very old: (9) 
fi. Tubes violet-reddish: (7) 
6. Tubes white, or becoming discolored in age; on wood of broad-leaved 
trees : (S) 
7. On conifers; pileus effuso-reflexed, grayish-white, villose, flexible to 
rigid: Polystictus abietinus Dicks. 
(Ooriolus abietinus). 
7. On broad-leaved trees ; imbricate, thin and parchment-like : 
Polystictus pergamenus Fr. 
8. Pileus effuso-reflexed, laterally connate, white; tubes 3-5 mm. long, 
diameter rather large: Polystictus biformis Klotsch. 
(Ooriolus biformis). 
8. Pileus dimidiate to fan-shaped, whitish ; tubes 1-3 mm. long, diameter 
smaller: Polystictus prolificans Fr. 
( Ooriolus prolificans) . 
9. Surface of pileus conspicuously hairy, zoned; pileus 3-8 mm. thick, 
corkv-leatherv, very variable: verv common: 
Polystictus hirsutus Fr. 
(Ooriolus nigromarginatus) . 
9. Surface of pileus glabrous or minutely velvety to tomentose:. . (10) 
10. Surface of pileus conspicuously zoned: (11) 
10. Surface of pileus inconspicuously zoned: (14) 
11. On trunks of Abies balsamea; pileus dimidiate, villose-tomentose, 
drab-colored with paler zones: Polystictus balsameus Pk. 
(Ooriolus balsameus). 
11. Not on conifers: (12) 
12. Pileus white or dingy white, pubescent, rather thick, imbricate 
radially lined or furrowed; tubes white: 
Polystictus pubescens Fr. 
(Ooriolus pubescens). 
12. Pileus of varied colors in zones, not white: (13) 
13. Pileus dimidiate, very imbricate, with glabrous shining zones of 
bright colors when young, becoming darker with age; tubes glist- 
ening; very common: Polystictus versicolor Fr. 
(Ooriolus versicolor). 
13. Pileus circular, spatulate, or fan-shaped, very thin, brownish-tan, 
with darker zones; margin often lobed: Polystictus planus Pk. 
(Ooriolus planellus). 
