1244 Wisconsin Academy of Sciences, Arts and Letters . 
Bidymium melanospermum (Fers.) Maebr. 
1794. Physarum melanospermum Pers.. Bom. N. Mag. Bot. f p. 89. 
1899. Bidymium melanospermum (Pei’s.) Macbr., N.-A. S.-M. 
p. 88. 
Macbride: ‘ 4 Sporatigia gregarious, hemispheric, depressed, um- 
bilicate below, stipitate or sessile; the peridium firm, dull brown 
in color, frosted with minute crystals of lime, breaking irregu¬ 
larly ; stipe, when present, short, stout, dull black, opaque, arising 
from a broad base or hypothallus; columella large, prominent; 
dark-colored, rough above, concave below; capillitium of more or 
less sinuous, usually dark colored threads, sparingly branched, 
and often with calciform thickenings; spore-mass black, spores 
by transmitted light pale, purplish gray, spinulose or rough, 
10-12/x.” Macbride adds that this is a well-marked and com¬ 
mon species, distinguished by its depressed sporangium and dark- 
colored, opaque stipe, wieh is very short.. 
Lister finds the plasmodium colorless or grey, the sporangia 
often confluent, white or grey mottled with purple-brown, and be¬ 
set with stellate crystals of lime. He finds the spores dark pur¬ 
plish-brown or purplish-grey, with a thick spore-wall, nearly 
smooth or spinose, 9-12 [x diameter. In other respects he does not 
differ from Macbride. 
Massee adopts the name, D. farinaceum Schrad. He diffesr 
but little from the foregoing descriptions. He says the spor¬ 
angia are at first white with a continuous crust of lime, which 
soon becomes broken up into white glistening granules scattered 
on the inner dark, wrinkled wall; stem expanding at the base 
into a rudimentary hypothallus; lie finds the spores minutely 
warted, 10-13y in diameter. 
In ray one collection I find a few confluent sporangia. Th« 
stellate lime crystals in the walls distinguish it from any P)tyset- 
rum, with some of which it might easily be confused. The fore¬ 
going descriptions leave nothing to add. This was collected at 
Blue Mounds July 23, 1904. It was growing on green moss and 
decayed wood. 
