248 Mycetozoa of North America 



2. Arcyria vitellina Phill. Grevillea 5: 115. 1877. (N. Y. B. G. 

 no. 5209, type material.) 



Arcyria versicolor Phill. Grevillea 5: 115, 1877. (N. Y. B. G. no. 5207, type 

 material.) 



Plasmodium? Total height 2.5 to 3 mm. Sporangia short- 

 stalked or sessile, gregarious or clustered, piriform or clavate, 1 to 

 2 mm. diam., more or less shining yellow or olivaceous yellow: 

 sporangial wall membranous, persistent except at the apex, yel- 

 low, papillose on the inner side. Stalk 0.2 mm. long, yellowish 

 brown, filled with spore-like cells, arising from a well-developed 

 hypothallus. Capillitium an elastic network of freely branching 

 threads 4-6 /x diam., triangular or oval in section, either uniformly 

 spinulose and marked with broken reticulation, or with one side 

 thickened and marked with transverse bars; threads arising from 

 the tube of the stalk and not attached to the sporangial wall; free 

 ends short-pointed. Spores yellow, smooth, 8-10 /n diam. 



Type locality: California. 



Habitat: On dead wood. 



Distribution: California, Colorado, Ontario, Oregon, *South 

 Dakota, Washington. 



Illustration: Lister, Mycetozoa ed. 3. pi. 175, OiS A. versicolor. 



A. vitellina and A. versicolor are the same, and were described 

 by Phillips on the same page, but as the former came first it must 

 be accepted as the name under present rules of nomenclature. 

 The species is allied to the yellow phase of A. ferruginea. 



3. Arcyria cinerea (Bull.) Pers. Syn. Meth. Fung. 184. 1801. 



Trichia cinerea Bull. Herb. Fr. pi. 477, fig. 3. 1789; Bull. Champ. 120. 

 1791. 



Plasmodium grayish white (Lister). Total height 0.8 to 4 

 mm. Sporangia stalked, gregarious or solitary, single or united in 

 clusters of two to six, ovoid or cylindrical, more rarely globose, 

 0.5 to 0.8 mm. diam., pale gray, greenish or bluish gray, or yel- 

 lowish; cup of the sporangium membranous, nearly smooth, 

 minutely papillose or reticulate, plaited at the base, pale gray or 

 yellowish. Stalk cylindrical, furrowed, 0.2 to 2 mm. long, 0.05 

 to 0.15 mm. thick, white, gray, or brown, filled with spore-like 

 cells. Capillitium a close network of gray or yellowish gray 

 threads, the upper and middle threads 2-4 n diam., closely warted. 



