STEMONITIS 161 



Reported from England, Denmark, Rumania and other European 

 localities, also Malay Peninsula, Japan. 



2. Stemonitis nigrescens Rex 



Proc. Acad. Nat. Sc. Phila. 1891 : 392. 

 PI. XI, Fig. 246. 



1909. Stemonitis fusca Roth, var. nigrescens Rex ex Torrend, Fl. Myx. 141. 



Sporangia gregarious in small, loose clusters upon a common hy- 

 pothallus, erect, cylindric, stipitate, 3-5 mm. tall, fuscous black * 

 becoming fuscous when blown; stem black, extremely short, about 

 0.5 mm. ; columella reaching the apex, violet-black, darker near the 

 surface; peridial net developed chiefly at the base, elsewhere incom- 

 plete or lacking; spores black in mass, violet-brown by transmitted 

 light, verrucose-reticulate as in S. fusca, but with reticulations less 

 marked, 8-9 n in diameter. 



The author of this species remarks: "This species is noteworthy for 

 its comparatively short stipes, its very spinulose spores, and its black 

 or nearly black color, the slight violet tint being only apparent on close 

 inspection, especially in fresh moist specimens." 



It is a small but very beautiful form, at first sight to be mistaken for 

 a short S. fusca, though much more intensely black before the spores 

 are shed. The capillitium is concolorous, the inner network of rather 

 few open meshes, the outer of large hexagonal openings, the arcuate 

 threads of which are remarkable for the size, and especially the number, 

 of the peridial processes, as many as five or six sometimes appearing 

 along one side of a single mesh. The stipe is very short, and the colu- 

 mella runs as a straight, gradually diminishing axis to the very apex 

 of the sporangium. Total height 3-5 mm. 



Lister follows Torrend in regarding this as a variety of S. fusca but it 

 seems distinct in size, habit and color. 



Not common. Pennsylvania, Virginia, North Carolina, Indiana, 

 Iowa, Arizona, Oregon, California; Wales. 



3. Stemonitis dictyospora Rost. 



Mon. 195. 1875. 

 PI. XI, Figs. 247, 248. 



1893. Stemonitis castillensis Macbr., Bull. Nat. Hist. S. U. Iowa 2 : 381. 



Sporangia slender, rigid, erect, 18-25 mm. tall, in large clusters, 

 4-8 cm. across, dark fuscous; columella prominent, reaching nearly to 

 the apex, abundantly branched, the branches forming an intricate dark 



