Bean—The Myxomycetes of Wisconsin. 
1233 
Physaram leucopus Link. 
1809. Physarum leucopus Link, Biss., I., p. 27. 
Macbride: ‘ ‘ Sporangia gregarious, stipitate, globose, snow- ' 
white, with a BidymiuwA ike covering of calcareous particles; 
stipe not long, conical or tapering rapidly upward, slightly sul- 
cate. brittle, from an evanescent hypothallus; columella none or 
small: capillitium consisting of rather long hyaline threads, con¬ 
necting the usual calcareous nodes, which are large, angular, snow 
white : spore-mass black; spores by transmitted light violet brown, 
distinctly warted, about 10/x.” He adds that the snow-white, 
nearly smooth stem and the small sporangia covered with loose 
ealcai'eous granules, distinguish this rare species. It looks like a 
small Bidymium sqvamulosuw 
Lister says, in part: “Plasmodium opaque-white. Sporangia 
grayish white or glaucous, gregarious or clustered, stalked, rarely 
almost sessile; stalk white, stout, thick, with a few shallow longi¬ 
tudinal furrows, erect, rigid, brittle, somewhat narrowing up¬ 
wards, chalk-white in section to the base, rising from a more or 
less developed white hypothallus. ” He finds the spores to be 
l-lOy in diameter. 
Massee differs in a few particulars: “Sporangia globose, 
broadly ellipsoid or a little depressed, stipitate or sessile, rarely 
elongate and flexuous or anastomosing, wall at first covered with 
a continuous snow-white coat of lime, which soon becomes broken 
up into smooth innate patches; stem variable in length, white, 
passing into a more or less evident hypothallus ; spores globose, 
dingy lilac, rather coarsely warted, warts almost black, 9-12/x 
diameter. ’ ’ 
The short, stout, white, rigid stipe is a distinctive characteris¬ 
tic of this species. I do not find any flexuous or anastomosing 
sporangia in my specimens. 
Our one group was found growing on dead wood beside the 
Windsor road, July 7, 1904. 
Physarum nucleatum Rex. 
1891. Physarum nucleatum Rex., Proc. Phil. Acad., p. 389. 
Macbride : “Sporaneria gregarious, spherical, % nim., white, 
stipitate; peri dial wall membranaceous, rupturing irregularly, 
