198 THE NORTH AMERICAN SLIME-MOULDS 



blance between C. friesiana, i. e. C. nigra, and the present species is 

 sufficiently remote. 



Lamproderma minutum Rostafinski seems to be a small form of 

 this species. Rostafinski bases his diagnosis upon the branching of the 

 columella, which is, as we have seen, inconstant, and upon the color- 

 less capillitium. This feature in specimens examined is also in- 

 constant. 



Occurring in large colonies on barkless decaying logs of various 

 species; the Plasmodium almost colorless. 



New England, Pennsylvania, Ohio, Louisiana, Texas, Mexico, 

 Nicaragua ; Vancouver's Island ; Ontario, Toronto, — Miss Carrie. 



4. Echinostelium DeBary 

 1873. Echinostelium DeBary, Rost., Versuch, p. 7. 



Sporangia distinct, globose, minute, the structure limited to a few 

 imperfect rib-like, loosely joined branches developed from the short 

 columella or stem-top, sustaining the spores. 



A single species : — 



1. Echinostelium minutum DeBy. 



1873. Echinostelium minutum DeBy., Rost., Versuch, p. 7. 

 Plate XIX., Figs. 11 and 11a 



Sporangia distinct, scattered, globose, very minute, 40-50 /u, stipi- 

 tate; the stipe, hair-like subulate, granular but hyaline; columella 

 minute or none; capillitium consisting of a few arcuate spinose 

 threads loosely united supporting the uncovered spores, spores globose, 

 colorless, smooth, 7-8 /a. — Rostafinski. 



This very singular and diminutive form, the least of all slime- 

 moulds, is probably widely distributed but the accident of discovery 

 is rare, DeBary found it once only, at Frankfurt am Main. 



Miss Lister reports its occurrence in England and Austria. In the 

 United States it has been seen but once on certain laboratory mate- 

 rial from Massachusetts, studied by Dr. Thaxter. 



Our drawing is after Rostafinski, IV., 68 ; Miss Lister follows No. 

 54, and so finds a bit of peridium below the two spores shown in the 

 figure, one on each side of a microscopic columella. 



