102 Mycetozoa of North America 



irregular plasmodiocarps, ochraceous yellow, yellow, or reddish, 

 sometimes fading to white, smooth or rugulose, rarely on a hypo- 

 thallus; sporangial wall single, membranous, densely charged with 

 colored lime-granules. Columella lacking, represented by an ele- 

 vation of the sporangial floor to form a hollow pseudo-columella, 

 prominent or indefinite. Capillitium consisting of slender, color- 

 less or dark branching threads, often with expansions at the base. 

 Spores brownish violet, spinulose, 8-12 n diam. 



Var. echinulatum Meylan, Bull. Soc. Vaud. Sc. Nat. 52: 450. 1919. 



Sporangia hemispherical, rotund, bright yellow; spores strongly 

 spinose. 



Type locality: Silesia. 



Habitat: On dead leaves, mosses, etc., in wet places. 



Distribution: Florida, Maine, Maryland, Massachusetts, 

 New Hampshire, New Jersey, New York, North Carolina, On- 

 tario, Pennsylvania, Virginia, Wisconsin; var. echinulatum, *New 

 Hampshire, New York, Pennsylvania. 



Illustration: Lister, Mycetozoa ed. 3. pi. 88. 



In North America, the species seems to be confined to the 

 eastern part, where it is common and often found in abundance. 

 There have been times when I have seen hundreds of fruitings in 

 a single day. The form is very variable in every particular, yet 

 not difficult to recognize because of its single wall, which gives it 

 an appearance distinct from that of any other Diderma. Euro- 

 pean specimens have a darker, brick-red color which is also seen 

 here occasionally. The hypothallus mentioned by other authors 

 is found in such collections, but is more the result of imperfect 

 development, and is not seen in the yellow and ochraceous forms, 

 which constitute practically all the developments. The hollow 

 columella is unique, and appears in most of the material. Lime- 

 knots and spike-like processes are occasionally present in the 

 capillitium. Var. echinulatum is well marked by the trim appear- 

 ance of the bright yellow sporangia, and the more coarsely marked 

 spores. I have found it on a number of occasions associated with 

 the typical form, when the latter appeared abundantly. 



12. Diderma Sauteri (Rost.) Macbr. N. A. Slime-Moulds 103. 

 1899. 



Chondrioderma Sauteri Rost. Mon. 181. 1874. 



Chondrioderma aculeatum Rex, Proc. Acad. Nat. Sc. Phila. 1891: 390. 1891. 



