Arcyria 251 



6. Arcyria globosa Schw. Schrift. Naturforsch. Ges. Leipzig 1: 

 64. 1822. 



Lacknobolus globosus (Schw.) Rost. Mon. 283. 1875. 



Plasmodium? Sporangia scattered or gregarious, stalked, 

 globose, 0.3 to 0.6 mm. diam., usually white, pale yellow from 

 fading, or brownish when stained; cup usually deep, occasionally 

 shallow, membranous, smooth or papillose, often minutely wrin- 

 kled transversely. Stalk pale yellow or brown, slender, 0.2 to 0.5 

 mm. high, filled with spore-like cells. Capillitium a close and 

 only slightly elastic network of colorless threads 2-4 /x diam., 

 marked with warts or spines usually arranged along three or four 

 dextral spiral lines, occasionally irregularly reticulate between the 

 spines. Spores colorless, 6-8 n diam., marked with a few scat- 

 tered warts. 



Type locality: North Carolina. 



Habitat: On fallen chestnut-burs of the preceding year, and 

 leaves of the chestnut oak. 



Distribution: Eastern continental North America; formerly 

 common but now rare. 



Illustration: Lister, Mycetozoa ed. 3. pi. 176, figs. g-i. 



This species was very common formerly, often associated with 

 Crateriiim concinniim on fallen chestnut-burs. I have found it 

 several times in recent years at altitudes of 3,000 feet or more in 

 the Appalachian range of mountains, where some chestnut trees 

 have survived the blight until now. In 1942 I found it on two 

 occasions on the dead leaves of the chestnut oak in eastern Penn- 

 sylvania. The habitat, white sporangia, and deep cups distin- 

 guish it from A. cinerea and A. pomiformis. 



7. Arcyria denudata (L.) Wettst. Verh. Zool.-Bot. Ges. Wien 

 35 (Abh.): 535. 1886. 



Clathrus denudatus L. Sp. Plant. 1179. 1753. 



Plasmodium white (Lister). Total height 2 to 3 mm. Spo- 

 rangia stalked, crowded or gregarious, ovoid or sub-cylindrical, 

 0.9 to 1.8 mm. high, 0.8 to 1 mm. broad, crimson, weathering to 

 reddish brown or brown, rarely pale red; cup of sporangium 

 membranous, firm, shining, plaited, smooth or marked with scat- 

 tered papillae and faint broken reticulations on the inner side. 

 Stalk cylindrical, 0.5 to 1 mm. high, 0.1 mm. thick, furrowed. 



