Stemonitis 147 



Illustration: Jahn, Ber. Deutsch. Bot. Ges. 41: 394, fig. 1. 



This species is clearly a departure from S. fusca, perhaps 

 caused by changing of the habitat of the plasmodium to the soil. 

 It has an extremely wide range of variation in the capillitium and 

 spores, and this, with the different habitat, requires its separation 

 from S. fusca. In some well-developed phases on drier material, 

 the resemblance to 5. fusca is pronounced, and separated speci- 

 mens may erroneously be taken for that species. The more 

 variable phases are in the wetter places, and the confluent charac- 

 ter of some of the sporangia bears a strong resemblance to the 

 genns Amaurochaete. In order to understand the species properly, 

 it must be studied from sufficient material in all its phases. For- 

 tunately, it is abundant when discovered, but does not last long. 

 The developments are fragile, and immediately on maturity they 

 are attacked by insects and devoured completely, so that nothing 

 is left after two or three days. It fruits apparently only once in 

 a season, usually in August, and these factors contribute to the 

 rarity of its collection. I have watched it, year after year, 

 developing in great abundance in the swamps of Long Island. 

 Amaurochaete trechispora is based on a collection made by Dr. 

 J. H. Faull, at Lake Timagami, Ontario, and described by Miss 

 Currie loc. cit. as S. fusca var. trechispora. There is nothing in 

 the type material to indicate other characters than those that 

 appear in Stemonitis trechispora. The collection is one that de- 

 veloped in a very wet area as seen by comparison with Long 

 Island material. 



5. Stemonitis confluens Cooke & Ellis, Grevillea 5: 51. 1876. 

 (N. Y. B. G. nos. 6180, 6181, 11995, authentic material.) 



Stemonitis splendens Rost. var. confluens Lister, Mycetozoa 112. 1894. 

 (N. Y. B. G. no. 11753, type material.) 



Plasmodium white (Lister). Total height 1 to 3 mm. Fructi- 

 fication dividing into many small groups of stalked, confluent 

 sporangia, 1 to 10 mm. across, rarely larger, almost black. 

 Sporangial wall evanescent, except for small, circular discs on 

 lateral extensions of the capillitium. Stalk weak, short, black, 

 continuing into the sporangium as a tortuous, irregular columella, 

 either to the top or dissipated in the capillitium. Capillitium of 

 rigid, dark brown threads, coarsely meshed to form an open net- 

 work, and continued as a surface-net which may be imperfect 



