266 THE MYXOMYCETES 



late calyculus; stipe very short or wanting; hypothallus thin but usually 

 in evidence; capillitium expanding to great length, forming an ex- 

 tremely flexile, plumose, pendulose open network of pale ochraceous 

 tint, the threads 3-4 /x in thickness, adorned with spinules, sharp-edged 

 transverse plates and sometimes rings, the surface marked by an in- 

 distinct reticulation; spore-mass buff or ochraceous; spores by trans- 

 mitted light colorless, smooth or nearly so, 7-8 fx. 



Common, especially on fallen willows. The expanded capillitia are 

 very soft and plume-like, waving and nodding, very lightly attached 

 below to the center of the peridial cup. The capillitial threads are 

 rough, with irregular spines and sharp-edged transverse plates, oc- 

 casionally extended to form rings. It resembles A . magna somewhat in 

 habit, size and spinescent capillitium, but the resemblance is superficial 

 only. The color is at once diagnostic, and the capillitium is after all 

 entirely different. 



Nova Scotia to Washington, south to Mexico and the Virgin Islands; 

 cosmopolitan. 



4. Arcyria virescens G. Lister 



Jour. Bot. 59 : 252. 1921. 



Sporangia cylindrical, stalked, clustered or crowded, often forming 

 large colonies, yellowish green; calyculus narrowly funnel-shaped, 

 reticulated and shiny within; stalks slender, straight or flexuose, dark 

 olive-green, 0.5-1.5 mm. long, free or adherent in clusters; capillitium 

 a loose elastic network of greenish or yellowish threads, free from the 

 cup and about 6 mm. long when expanded, the threads 4-6 fi wide, 

 marked with scattered groups of close-set, prominent transverse ridges, 

 3-5 ix high, the remaining surface irregularly reticulate and shiny; 

 spores yellowish green in mass, with a few scattered warts, 7-8 ju. 

 Plasmodium white. 



Resembling A . nutans, but differing in the greenish color, the narrow 

 calyculus and the capillitial markings. 



Rare. Iowa, Oregon; Ceylon, Malay Peninsula, Queensland, Mada- 

 gascar. 



5. Arcyria versicolor Phillips 



Grev. 5 : 115. 1877. 

 PI. XVII, Figs. 456, 457, 458. 



1877. Arcyria vitelline Phillips, Grev. 5 : 115. 



Sporangia gregarious or more or less crowded, pyriform or clavate, 

 olivaceous yellow, sometimes becoming reddish, stipitate; peridium 



