160 THE NORTH AMERICAN SLIME-MOULDS 



spore-diameter, free-ending branch-tips not lacking; the spores by 

 transmitted light distinctly brown, the epispore a beautiful reticula- 

 tion, a dozen or more cells to the hemisphere, 10-12 /n. 



This is entered sometimes as a variety of S. fusca to which species 

 relationship would seem remote. The differences lie in form, color 

 and structure. The spores alone are distinctive ; there are none such, 

 so far, none just like them, elsewhere in the genus. Torrend and 

 Lister both enter the form as varietal ; why not set it out, and save 

 questions? The habitat approaches that of Amaurochaete, but the 

 sporangia are distinct. 



For our specimens we are indebted to the kindness of Dr. Roland 

 Thaxter. The specimens were taken in a half-dry marsh, near 

 Cambridge. 



Material from Toronto sent by Professor Faull is also provision- 

 ally here referred. The form has netted spores, but they are not 

 quite the same. The structure besides is more that of an amauro- 

 chaete; it has the peculiar basal webs and band-like stipes at base, 

 stipes that never rise from horizontal to perpendicular and character- 

 ize Reticularia and especially Brefeldia as well as the usual amauro- 

 chaete. See Plate XX., Figs. 9, 9n, 9b. 



3. Stemonitis fusca (Roth) Rost. 



Plate VI., Figs. ^, ^a, ^b 



1787. Stemonitis fusca Roth, Rom. Mag. Bot., I., p. 26. 



1875. Stemonitis fusca (Roth) Rost., Mon., p. 193. 



1892. Stemonitis fusca Rost., Massee, Mon., p. 72. 



1895. Stemonitis fusca Roth, List., Mycetozoa, p. 110. 



1899. Stemonitis fusca (Roth) Rost., Macbr., N. A. S., p. 115. 



1899. Stemonitis maxima Schw., Macbr., A^. A. S., p. 116. 



Sporangia tufted, generally in small clusters 6-8 mm., the indi- 

 vidual sporangia slender, cylindric, blue-black or fuscous, becoming 

 pallid as the spores are lost, stipitate; stipe short, about one- fourth 

 the total height, black, shining; hypothallus scanty, but common to 

 all the sporangia; columella prominent, attaining almost the apex of 

 the sporangium, freely branching to support the capillitial net; capil- 

 litium of slender dusky threads, which freely anastomose to form a 

 dense interior network, and outwardly at length combine to form a 



