Physarum 39 



Stalk 0.5 to 1 mm. high, concolorous or paler. Columella short, 

 conical. Capillitium delicate, persistent, with small rounded 

 lime-knots, concolorous with the other lime. Spores pale brown- 

 ish lilac, nearly smooth, 7-8 n diam. 



Type locality: Pennsylvania. 



Habitat: On dead wood. 



Distribution: Pennsylvania. 



Illustration: None published? 



This species is intermediate in color between P. pulcherrimum 

 and P. globuliferum . In the latter species the lime is sometimes 

 faintly pink or lilac. Such collections must be regarded as P. 

 globuliferum, as the color should be deep enough to be seen when 

 viewing the colony as a whole with a hand-lens. The species is 

 known only from Pennsylvania, where it was found by the late 

 Mr. Hugo Bilgram, and the author with his associates. 



10. Physarum citrinum Schum. Enum. PI. Saell. 2: 201. 1803. 



Plasmodium bright yellow (Lister). Total height 0.8 to 2 

 mm. Sporangia gregarious, stalked, erect, rarely sessile, globose, 

 0.4 to 0.7 mm. diam., rugose, yellow to yellowish gray; sporangial 

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

 Stalk yellow, stout, somewhat furrowed, 0.1 to 1.3 mm. high, 

 chalky in cross-section from the presence of lime, which is some- 

 times in nodules. Columella short, conical, or obtuse. Capil- 

 litium a somewhat close, persistent network of hyaline threads, 

 with fiat expansions at the axils, and numerous yellow lime-knots, 

 varying in shape and size, usually rounded. Spores lilac-brown, 

 almost smooth, 7-10 n diam. 



Type locality: Denmark. 



Habitat: On dead wood and mosses. 



Distribution: ^Colorado, New Hampshire, Ohio, *Oregon, 

 Pennsylvania, Tennessee, *Washington. 



Illustration: Lister, Mycetozoa ed. 3. pi. 20. 



Typical examples of this species, with pronounced yellow lime, 

 are very rare from North America; it is more abundant in Europe. 

 It is practically the same as certain phases of P. globuliferum, dif- 

 fering only in color. In the latter species, the lime often shows 

 pale yellowish tints, approaching thereby P. citrinum, but such 

 specimens must be regarded as intermediate, and closer to P. 

 globuliferum. The yellow hypothallus mentioned in other de- 



