1226 Wisconsin Academy of Sciences, Arts and Letters. 
Physarum sixmosum (Bull.) Weinm. 
1791. Reticularia sinuosa Bulliard, Champ, p. 94, t. 446, fig. 3. 
1828. Physarum sinuosum Weinmann, Fries teste, l. c. 
Macbride: “Sporangia distinct or plasmodiocarps the plas- 
modiocarp creeping in long vein-like reticulations or curves, lat¬ 
erally compressed; sometimes distinct and crowded, always ses¬ 
sile. Peridium double; the outer thick, calcareous, fragile, snow- 
white: the inner delicate, the dehiscence by longitudinal fissure. 
Capi]litium strongly developed with abundant white, calcareous 
granules. Spores smooth, dull violet, 8-9/x. Easily recognized 
at sight by its peculiar form, bilabiate and sinuous. ’ ’ 
Saccardo credits the generic name of this species to Rostafin- 
ski. He calls the color snowy, grayish, or yellowish-white. The 
remainder of his description does not differ from Macbride’s. 
Lister finds the sporangia sometimes pulvinate, bursting irreg¬ 
ularly, and white, gray, or yellowish. The spores he calls violet- 
brown, spinulose, and 8-10y in diameter. 
The general character of my specimens is well described above. 
I find the three different colors in different specimens, the snowy, 
grayish, and the yellowish-white. The spores are from 7-10/t 
in diameter and are distinctly though minutely spinulose. 
One specimen found upon dead oak leaves on a lawn in Madi¬ 
son, July 20, 1904, has a quantity of Biderma hemisphericum 
mingled with it. Another specimen was found upon dead oak 
leaves and small stems in Yilas woods, July 16, 1904, another up¬ 
on dead leaves I found at Blue Mounds, July 23, 1904, and still 
another was collected at Blue Mounds July 13, 1907. 
Physarum contextum Persoon. 
1796. Biderma contextum Persoon, Ohs. Myc., I., p. 89. 
1801. Physarum contextum Persoon, Syn. Meth ., p. 168. 
Saccardo: “Sporangia distinct, sessile, densly crowded, sub- 
rotund or reniform, base broad, 1-1.5 mm. long, .25 mm,, wide; 
peridia double, outer layer thick, calcareous, yellow or yellowish 
white, inner layer thin, yellowish; capillitium with numerous, 
irreguar. closely packed, colorless, calcareous granules; columella 
commonly none; spores very dark, spinulose, 11-13/a diameter. 
