tapering setae. Cells quadrangular in the basal portion, cylindrical 

 in the vertical branches; 4r-10fji in diameter, 6-12/x long. 



In lakes and ditches; on large filamentous algae and submerged 

 vegetation. Wis. 



Stigeoclonium stagnatile (Hazen) Collins 1909, p. 301 



PI. 11, Fig. 3 



Thallus attached at first, later free-floating. Filaments long and 

 sparingly branched; branches alternate but often opposite also in 

 origin, short and ending in blunt points, or long and setiferous. 

 Cells 8—11/1, in diameter and up to SOju, long. 



Floating in lakes and swamps. Mich., Wis. 



Stigeoclonium suhsecundum Kuetzing 1843, p. 253 

 PL 10, Figs. 3, 4 



Filaments elongate and sparingly branched; the branches grad- 

 ually and gracefully tapering to fine points, alternate in origin, 

 sometimes short and composed of only 2 or 3 cells. Cells elongate 

 and cylindrical but with slight constrictions at the cross walls; 12-18|U, 

 in diameter and up to 75/a long. Chloroplast a thin, parietal plate. 



Generally distributed in a variety of lakes but always in quiet 

 water protected from wave action; older plants free-floating. Mich., 

 Wis. 



Stigeoclonium tenue ( C. A. Ag. ) Kuetzing 1843, p. 253 



Thallus an elongate tuft of very slender, gracefully tapering fila- 

 ments, the branches mostly opposite, but occasionally alternate 

 (solitary), tapering to setae. Cells long and cylindrical (sometimes 

 nearly quadrate), or with walls slightly convex and constricted at 

 the cross walls; 7-10/a in diameter below, 5-6/x in the branches. 



Mich. 



CHAETOPHORA Schrank 1783, p. 124 



Thallus consisting of highly branched filaments arising from a 

 prostrate palmelloid mass of cells and inclosed by a mucilage of such 

 firm consistency as to give the thallus a definite shape, globose, 

 hemispherical, or arbuscular. Branches tapering to either a blunt 

 point or a long, multicellular, hyaline hair. Chloroplast a parietal 

 band which in the upper cells completely covers the lateral walls; 

 with 1 or more pyrenoids. Zoospores and isogametes formed in the 

 outer cells of the branches. 



[117] 



