Physarum 37 



rounded lime-knots, the columella, and the small pale spores. 

 In many collections there is a pale yellow shade to the lime, show- 

 ing an approach to P. citrinum or P. rnurinum. Colonies of 

 sporangia with angular and branching lime-knots are sometimes 

 found. Together with P. rnurinum, P. citrinum, P. pulcherri- 

 mum, P. pulcherripes, and P. Bilgramii, it forms a group, the 

 species of which are separated mainly by color distinctions, but 

 similar otherwise, so that intermediate forms occur. P. globulife- 

 rum prefers a dryer habitat than some of the related species. 



6. Physarum pulcherripes Peck, Bull. Buff. Soc. Nat. Hist. 1: 64. 



1873. (X. V. B. G. no. 11010, type material.) 



Plasmodium orange-red. Total height 1 to 2 mm. Sporangia 

 stalked, globose, about 0.5 mm. diam., yellow-orange, orange-red, 

 or brownish, sometimes gray from absence of lime; sporangial 

 wall membranous, with deposits of orange-red lime, usually 

 abundant. Stalk brittle, thick, 0.5 to 1.5 mm. long, somewhat 

 narrowed upward, densely charged with red or brown lime- 

 granules or crystalline nodules, usually darker at the base. 

 Columella small, conical or subglobose, often dark red in color. 

 Capillitium persistent, a dense network of hyaline threads with 

 red or reddish brown lime-knots. Spores violet-brown, nearly 

 smooth, 8-10 (X diam. 



Type locality: New York. 



Habitat: On rotten wood and mossy logs; common. 



Distribution: Throughout the eastern United States; *Canal 

 Zone, Oklahoma, Ontario, Quebec, *Washington. 



Illustration: Lister, Mycetozoa ed. 3. pi. 17. 



7. Physarum murinum Lister, Mycetozoa 41. 1894. (N. Y. 



B. G. no. 11098, authentic material.) 



Plasmodium? Sporangia scattered, stalked, globose, rugu- 

 lose, about 0.5 mm. diam., grayish or yellowish brown; sporangial 

 wall membranous, with included clusters of brown lime-granules. 

 Stalk erect, 0.5 mm. long or longer, of uniform breadth, brown 

 or brownish, furrowed, containing dense deposits of white or 

 brown lime-granules. Columella small, conical or subglobose. 

 Capillitium a dense network of branching, hyaline threads, per- 

 sistent after dispersal of the spores, with ovoid, brown lime-knots, 

 or a looser network with numerous, elongate, irregularly branch- 



