Il6 THE NORTH AMERICAN SLIME-MOULDS 



Apparently not common east, though widely distributed. 

 Pennsylvania, Ohio, Tennessee, Iowa ; Black Hills, South 

 Dakota ! Apparently more common on the Pacific coast. Cali- 

 fornia, Oregon, Washington. Some California specimens have 

 spores without warts, even when magnified 1400 diameters. 



3. STEMONITIS NIGRESCENS Rex. 



1891. Stemonitis nigrescens. Rex, Proc, Phil. Acad., p. 392. 



Sporangia gregarious, upon a common hypothallus, erect, 

 cylindric, stipitate ; stipe black, extremely short, about half a 

 millimetre; columella reaching the apex; capillitium violet black, 

 darker near the surface, forming a complete superficial net at 

 the lower part of the sporangium only, elsewhere irregular or 

 vanishing ; spore-mass nearly black ; single spores violet black 

 under the lens, the epispore spinulose and reticulate, about 8 /u-. 



The author of this species remarks : " This species is note- 

 worthy 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 vS. maxima, though much more intensely 

 black. 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 columella runs as a straight, 

 gradually diminishing axis to the very apex of the sporangium. 

 Total height 5 mm. 



Pennsylvania. 



4. STEMONITIS MAXIMA Schweinitz. 



PLATE VI., Figs. 4, 4 a, 4 b. 

 1834. Stemonitis maxima Schw., N. A. F., p. 260, No. 2349. 



Sporangia in more or less widely scattered tufts at first dark 



