REVISION OF THE NoRTH AMERICAN HYDNACEAE 165 
original description, except I observe the spores to be distinctly 
oblong, whereas Dr. Peck says “ globose 4 и wide.” 
7. PHELLODON Karst. Rev. Myc. 3': 19. 1881 
Plants chiefly terrestrial, mesopodous, often deformed, usually 
light colored, whitish, grayish or buff, sometimes dark ; substance 
fibrous, tough, often thin, fragile when dry, sometimes in two 
layers, the outer felty, soft, the inner hard, compact ; spores white 
or hyaline, usually echinulate. 
The genus as here defined is closely related to Hydnellum and 
perhaps all the forms should be included in the one genus as was 
at first intended in this paper, but the spore characters are so dis- 
tinct and constant that it seems desirable to recognize these species 
as constituting a closely related genus. 
Under low powers of the microscope the spores frequently 
appear to be smooth but with high powers I have always found 
them roughened with exceedingly fine points. Іп Hydnellum the 
roughening of the spores is coarse enough to be detected with 
low powers of the microscope and appears as rounded protuber- 
ances often so large as to cause the spore to appear irregular in 
outline. While high powers of the microscope are often neces- 
sary to determine the character of the roughening and sometimes 
even that the spores are rough in this genus, the tough substance 
combined with the white spores is usually sufficient to separate it 
from others closely allied. 
Synopsis of the Specie 
Substance of pileus in two distinct layers, the upper soft ye and the lower more 
compact, darker; plants usually with odor. 
Compact part of substance and core of stem blacki 
Surface of pileus floccose-tomentose, phrase depressed. 
: пі 
ee: 
Surface of pileus pubescent to villose, azonate, convex, rarely depressed. 
2. Р. alboniger. 
Compact part of substance and core of stem, grayish or light colored. 
Surface of pileus brown to blackish brown, with a white margin ; odor strong 
n fresh, milder when dry. ‚ putidus AIR 
Surface of pileus grayish fuscous to smoky, ее. са. odor devel- 
oped in dryin ; | 
рани томан, irregular, subsessile, forming crust-like masses. 
Р. vellereus. 
Pileus subpubescent to glabrous, subregular ; stem slender. 
P. graveolens. 
