MICHIGAN ACADEMY OF SCIENCE. 
7:i 
base to apex of fruit-body. Ripe spore-mass powdery. Dirty white peri- 
dium. 
H ysterangiaceae. 
1. Phallogaster saccatus Morg. This seems almost more closely related 
to the Phallinales, since the gleba deliquesces at maturity. It grows on 
rotten wood near Ann Arbor, to which it is attached by white strands. Fruit- 
body small, pear-shaped. Rare. Above ground. 
Most of the family are subterranean; the columella if present does not 
extend through the fruit-body. i 
Hymenogastraceae. 
1. Hymenogaster nanus Mass, was found within the city of Ann Arbor in 
a grove. It has the appearance of a tuber, but has basidia instead of asci. 
It grows underground. Careful search might reveal many more in the state. 
III. 
Ly coper dinales. (The puff-balls.) 
The fruit-body is above ground. A capillitium is present and its threads 
are mixed with the copious spores which fill the fruit-body with a dry, dusty 
mass when mature. The peridium is composed of two layers ; the outer 
layer may be a firm and persistant coat bursting or splitting into fragments, 
or it may be soft, fragile and more or less deciduous (called cortex.) The 
various modes of dehiscence of the outer or inner layer determines largely 
the genus. There is only one family. 
Lycoperdaceae. * 
Key to Genera. 
(a) Outer peridium thick, splitting into star-like segments which become 
reflexed (b) 
(a) Outer peridium (cortex) soft, disappearing or temporarily persisting 
as warts or spines, flocci, etc (c) 
(b) Columella present; threads of capillitium simple, tapering to each ex- 
tremity 1 . Geaster. 
(b) Columella none; capillitium threads very long and interwoven 
Astraeus. (See Plectobasidinales.) 
(c) Fruit-body globose, entirely filled by spores and capillitium, i. e., 
without a sterile base, loosened at maturity from place of growth (d) 
(Bovistella echinella has no sterile base.) 
(c) Fririt-bodv sub-globose, obovoid or turbinate, tending to be longer 
than broad, with sterile tissue within the stem-like base, normally remaining 
attached to place of growth (f) 
(d) Outer peridium splitting in two, so that lower part remains in the 
ground; inner peridium dehiscing by a pore on the under side and carrying 
upper half of outer peridium with it when loosened from the place of growth. 
Capillitium threads simple 2. Catastoma. 
(d) No such splitting of outer peridium (e) 
(e) Threads of capillitium free, short, dichotomously branched. 
3. 'Bovista. 
♦Considerable disagreement is shown by different mycologists in the placing of the various species, 
largely due to the absence of exact knowledge of the development of different forms, so that a spe- 
cies has been put under a number of different genera from time to time. 
