140 THE NORTH AMERICAN SLIME-MOULDS 



long brown or black, tapering upward ; hypothallus well devel- 

 oped, brown or purple, usually not continuous ; columella 

 swollen, obtuse, short at best, hardly attaining the centre of 

 the sporangium ; capillitium very rigid, of simple or sparingly 

 branched, dark brown threads radiating from the clavate apex 

 of the columella and only here and there anastomosing toward 

 the surface, the ultimate divisions distinctly rough ; spores lilac 

 brown, rough, 10-12.5 ^. 



This species is well described and illustrated in Rostafinski's 

 Monograph. It is well marked by its clavate columella and 

 peculiarly simple, dark rigid capillitium, the branches of which 

 rise in great numbers immediately from the columella, and 

 maintain their primitive thickness during the greater part of 

 their length. The transverse vincula are often at right angles 

 , to the principal branches, and the meshes, where formed, are 

 often long and rectangular. Externally, it resembles L. arcyri- 

 onema, but is by its spores and capillitium instantly distin- 

 guished. Rostafinski gives the spores 12.5-14.2 /^. Large 

 spores are less common in the specimens before us. Lister 

 figures a sessile variety. 



Not common. New England, New York. 



2. LAMPRODERMA SAUTERI Rost. 



PLATE V., Figs. 4, 4 a. 



1875. Lamproderma sauteri Rost., Mon., p. 205. 



1892. Lamproderma robusta (Ell. and Everh.) Mass., Mon., p. 99. 



1894. Lamproderma arcyrioides (Somm.) Morgan, Jour. Cin. S0c.,p. 47. 



Sporangia gregarious, globose, dull black, the peridium when 

 present silvery, shining, or simply smooth, transparent and 

 without iridescence, stipitate ; stipe short, black, tapering 

 rapidly upward, annulate with the persisting base of the 

 peridium ; columella short, thick, truncate, and widened at 

 the top ; hypothallus well developed, brown or purple ; capil- 

 litium dense, made up of dark brown branches, numerous and 

 rather slender, repeatedly branched and anastomosing toward 



