66 Mycetozoa of North America 



white or pale yellow lime-knots, sometimes densely massed in the 

 middle, and connected by short threads. Spores brownish lilac, 

 minutely and evenly spinulose, 7-8.5 n diam. (Plate 8, fig. 2.) 



Type LOCALITY : Philadelphia, Pennsylvania. 



Habitat: On dead leaves. 



Distribution: Florida, Kansas, New Jersey, New York, 

 North Carolina, Ontario, Pennsylvania, Tennessee. 



Illustration: Lister, Mycetozoa ed. 3. pi. 22, fig. a, as P. 

 sessile. 



On the Lister plate cited, ^ig. b represents a form now regarded 

 as P. sulphureum var. sessile, and entirely different from P. su- 

 perbum. P. sessile was described originally by BrandzS to include 

 two different forms, a white one, and a yellow one. Later, 

 Br^ndza proposed the name P. aureum for the yellow form sepa- 

 rated from P. sessile, describing it with spores 10-12 m diam., and 

 figuring cylindrical plasmodiocarps. Whether or not P. aureum 

 Brandza is the same as P. superbum is unknown here, but the 

 name is untenable as it was used by Persoon (Roemer, N. Mag. 

 Bot. 1 : 88. 1794) for a form now regarded as synonymous with 

 P. viride (Bull.) Pers. The white form retained by Brandza as 

 P. sessile is a phase of P. cinereum as indicated by specimens in 

 the Herbarium of the New York Botanical Garden. 



P. superbum is a handsome form, rich in colors when perfectly 

 matured. It is well distributed in North America, and probably 

 not rare. 



44. Physarum gyrosum Rost. Mon. HI, in part. 1874. 



Plasmodium white or yellowish. Sporangia sessile, much 

 compressed, confluent, clustered, and forming rosettes 1 to 4 mm. 

 diam., pinkish gray, usually attached by strands to a dull red 

 hypothallus; sporangial wall membranous, with clustered deposits 

 of white or reddish lime-granules. Capillitium a scanty network 

 of hyaline threads with numerous, large, white, transversely 

 placed, fusiform or irregular lime-knots. Spores pale brownish 

 violet, minutely spinulose, 7-10 /x diam. (Plate 8, fig. 3.) 



Type locality: Europe. 



Habitat: On decaying ground material, composts, etc. 



Distribution: Florida, Indiana, *Iowa, Kansas, Louisiana, 

 Mississippi, New York, Pennsylvania, Virginia. 



Illustration: Lister, Mycetozoa ed. 3. pi. 52. 



