COMATRICHA 185 



less continuous, reddish brown; columella tapering upward, black, 

 attaining more or less completely the apex of the sporangium; capil- 

 litium arising as rather stout branches of the columella, soon taking 

 the form of slender, nexuous, brownish threads, which by repeated 

 anastomosing form at length a close network, almost as in Stemonitis, 

 the free, ultimate branches very delicate and short; spore-mass dark 

 brown; spores by transmitted light pale, almost smooth, except for 

 the presence of a few scattered but prominent clusters of warts, of 

 which four or five may be seen at one time, 5-7.5 /jl. 



This is our most common North American species. It occurs every- 

 where on decaying wood, sometimes in remarkable quantity, thou- 

 sands of sporangia at a time; sometimes on leaves. The plasmodium, 

 watery white in color, infests preferably very rotten logs of Quercus, 

 on which in June the sporangia rise as white or pallid columns. The 

 peridium is usually exceedingly delicate, less seldom seen here than 

 in some other species, it is true, but easily overlooked; occasion- 

 ally it tends to persist. The spores when fresh have a distinct violet 

 or bluish tinge; in old specimens they are almost colorless. In any 

 case they are well marked by the clustered warts. 



This is probably Mucor stemonitis Scopoli (1772), although the 

 description is scarcely diagnostic. But Scopoli, by citing Hall, Gleditsch 

 and Micheli, so defines the form as to leave small doubt that he had 

 before him our common species. Schaeffer's figures also come to the 

 rescue, which, though by no means satisfactory, yet can probably refer 

 to no other species. Stemonitis typhina Wiggers (1780) also seems to 

 be this species and this specific name is adopted by Persoon and 

 Rostafinski. However, Bulliard gives the first good account and figure, 

 and in accordance with the decision of our English colleagues, the name 

 used in the famous Champignons is here retained. 



Widely distributed. Nova Scotia to Washington, south to Nicaragua, 

 British Guiana, Brazil and Argentina; common in the old world. 



22. Comatricha rubens Lister 



Mycetozoa 123. 1894. 



Sporangia gregarious, globoid or ellipsoidal, 1-1.5 mm., pink-brown, 

 stipitate; peridium persistent below; stipe 0.5-1 mm., black, shining; 

 columella more than half the sporangium in height, giving off on all 

 sides the brownish violaceous, flexuose threads of the capillitium, 

 somewhat thickened and broadly attached to the persisting peridial 

 cup; spores lilac-brown, spinulescent, 7-8 m- 



Somewhat resembling a lamproderma, but the capillitium arising 



