28 THE NORTH AMERICAN SLIME-MOULDS 



white. Capillitium well developed, furnished with lime. Spores 

 thin-walled, ellipsoidal, violaceous, plicate-rugose, 14-16 x 



11-12 fJi. 



Not common. Found occasionally in shaded situations on 

 piles of rotting straw. The spores are, no doubt, many of them 

 ellipsoidal ; some are spherical ; all are decidedly spinulose, 

 perhaps might appear plicate-rugulose when dry or shrunken. 

 Calcareous nodules very large and irregular, white. 



Schweinitz, N. A. F., 2365, described this species as Enteridium 

 cinereum. Rostafinski referred it to the genus Physarum, but 

 was obliged to adopt also a new specific name, as that suggested 

 by Schweinitz was already in use in the genus PJiysarum. Zopf, 

 Die PilztJiiere, p. 149, founds a new genus on what .seems to 

 be the same form as here considered. This he publishes as 

 ALtJialiopsis stercoriformis Z. Massee regards the specimens 

 discovered by Zopf as belonging to the genus Fuligo, and Lister 

 regards Rostafinski's type as Fuligo, and includes Zopf's mate- 

 rial under the Rostafinskian species. The character of the 

 capillitium and the spores is peculiar, but suggests PJiysarum 

 rather than Fuligo, as does also the calcareous cortex, both in 

 its purity and in the mode of its deposition. Small, isolated 

 plasmodia are in macroscopic appearance not unlike PJiysarum 

 diderma. Besides, there are no imperfectly formed sporangia, 

 as in Fuligo. 



Generally distributed eastward. New England, Pennsylvania, 

 Ohio, Alabama, Iowa. 



2. PHYSARUM SINUOSUM (Bulliard) Weinm. 



PLATE VIII., Figs. 6 and 6 a. 



1791. Reticularia sinuosa Bulliard, Champ., p. 94, t. 446, Fig. 3. 



1796. PJiysarum bivalve Persoon, Obs. Myc., I., p. 6, t. i, Fig. 2. 



1828. Physarnm sinuosum Weinmann, Fries teste. I.e. 



1829. Physarum sinuosum Fries, Syst. Myc., III., p. 145. 



1875. Physarum sinuosum (Bull.) Rostafinski, Monograph, p. 112. 



1892. Physarum sinuosum Rost., Massee, Mon., p. 305. 



1894. Physarum bivalve Pers., Lister, Mycetozoa, p. 57. 



1896. Arigioridium sinuosum (Grev.) Morgan, Cin. Soc. Nat. Hist., p. 75. 



