80 Mycetozoa of North America 



or branching lime-knots, usually white but often yellow, or 

 occasionally reddish or brownish. Spores violet, almost smooth, 

 7-10 n diam. 



Var. Candida (Pers.) R. E. Fries, Svensk Bot. Tidskr. 6: 744. 1912. 

 Fuligo Candida Pers. Obs. Myc. 1: 92. 1796. 



Aethalia and lime-knots white. 



Var. nifa (Pers.), R. E. Fries, Svensk Bot. Tidskr. 6: 745. 1912. 

 Fuligo rufa Pers. Neues Mag. Bot. 1: 88. 1794. 



Aethalia dull brick-red; lime-knots concolorous or white. 



Type locality: Europe. 



Habitat: On dead wood and piles of decaying vegetation. 



Distribution: Common and abundant throughout North 

 America. 



Illustration: Lister, Mycetozoa ed. 3, pi. 74. 



Other varieties have been supported on the texture and color 

 of the cortex, and the color of the plasmodium, but much of this 

 variation is probably due to atmospheric conditions prevailing 

 at the time of development, or the food of the plasmodium. 

 Fruitings on similar habitats, and at the same time, are usually 

 alike. On one occasion in Pennsylvania, all developments in dif- 

 ferent places were of about the same size, and had a firm, per- 

 sistent cortex. Often, in quiet, shaded places, the species, and 

 particularly var. Candida, will form ecorticate aethalia which may 

 be as much as a foot across. The surface will then have a laby- 

 rinthine structure, and, when the aethalia are small and with 

 little lime on the surface, will bear a marked resemblance to the 

 rosettes of Physarum gyrosum. They have been mistakenly 

 regarded as plasmodiocarps of that species, but are merely small, 

 ecorticate phases of var. Candida of F. septica. Aethalia also 

 occur with a labyrinthine structure perfected below a cortex, 

 which is firm and separable therefrom. This species is extremely 

 variable in size, form, and color of the aethalia, but in contrast, 

 the spores are fairly constant, usually somewhat pale and almost 

 smooth, and rarely a little darker and rougher. Occasionally the 

 lime in the sporangial wall is in the form of crystalline nodules. 



2. Fuligo intermedia Macbr. N. A. Slime-Moulds cd. 2. 30. 

 1922. 



Fuligo cinerea (Schw.) Morg. var. ecorticala Lister, Mycetozoa ed. 3. 69, in 

 part. 1925. 



