PHYSARUM 37 



This has been distributed in the United States as P. confer- 

 tnm Macbr., but comparison with material in the Schweinitzian 

 herbarium at Philadelphia leaves no doubt as to the proper 

 specific name. The calcareous covering in the specimens re- 

 ferred to is wanting, and there are no reticulate forms such as 

 Schweinitz would have us see according to his description. 

 See, however, Morgan, y#;/r. Cin. Soc., 1896, p. 99. 



14. PHYSARUM NEWTONI Macbride. 



PLATE XIV., Figs. 5, 5 a, 5 b. 



1893. Physarum newtoni Macbr., Butt. Lab. Nat. Hist. Iowa, II., p. 390. 



Sporangia simple, gregarious, short stipitate or sessile, glo- 

 bose or flattened, when not globose depressed and deeply um- 

 bilicate above, purple, smooth, thin-walled, stipe when present 

 very short and concolorous ; columella none ; hypothallus none ; 

 capillitium abundant, delicate, with more or less well developed 

 nodules, which are also concolorous ; spores by transmitted 

 light, dark brown, thick walled, rough, nucleated, about 10 p. 



A very handsome little species collected by Professor G. W. 

 Newton in Colorado, at an altitude of several thousand feet. 

 Easily recognized by its almost sessile, rose purple, generally 

 umbilicate sporangium. 



15. PHYSARUM C^SPITOSUM Schweinitz. 



1831. Physarum ccespitosum Schweinitz, N". A. f. 9 258. 



1869. Diderma citrimim Peck, Rep. N. Y. Mus., XXII., p. 89. 



1879. Physarum citrinellum Peck, Rep. N. Y. Mus., XXXI., p. 55. 



1894. Craterium citrinellum Lister, Mycetozoa, p. 74. 



Sporangia gregarious, or scattered globose, short-stipitate, 

 pale yellow or ochraceous, smooth or slightly roughened by the 

 presence of minute lime particles ; peridium more or less dis- 

 tinctly double, the outer calcareous, fragile, the inner very deli- 

 cate, with here and there a calcareous thickening, ruptured 

 irregularly ; stipe very short, half the sporangium, fuliginous, 

 furrowed, expanded below into an imperfectly defined hypo- 

 thallus ; capillitium abundant, the nodes stellate-angular, large, 



