CLADOPHORA. 127 



C. glomerate. Fructiferous cells terminal. Cell -membrane 

 often thick ; cells cylindrical, 5-8 times longer than broad ; 

 those of the branches rather shorter. Contents of cells 

 arranged somewhat lax-spirally. 



Diameter of stems, 80-110 //. 

 Diameter of branches, 35-50 yw. 



Rapid waters, Niagara, Portage, N. Y. 

 Plate CXI, figs. 1, 2, specimen from Portage. 



CLADOPHORA GLOMERATA, Kg. 



Branches and branchlets of the second and third order 

 fasciculate or penicellate. The cell contents of the larger 

 cells applied in a net-like, or somewhat spiral manner, to 

 the interior of the walls. Walls of cells externally smooth. 

 The zoospores, (zoogonidia) always escape from terminal 

 cells ; lower cells are sterile. 



Diameter of cells of stems, 60-100 yu. 

 Diameter of cells of branches, 30-50 ju. 



A variable species ; the lines between different varieties 

 are difficult to determine; the following may be enumerated. 



a. Var. GENUINA, Kirch. 



Bright vegetative green, 6-12 inches long, much branched ; 

 the ultimate branchlets more or less penicellate ; cell -mem- 

 brane firm ; articulations of the stems generally about 6-7, 

 and of the branches, 3-6 times longer than broad. 

 From rapid streams. 



b. Var. MUCOSA, Kg. 



Bright darker green, somewhat mucous, not as long as 

 (a), lighter structure and thinner membrane. 

 Mountain streams. 



c. Var. RIVULARIS. Eab. 



/ 



2-4 inches long, branches somewhat scattered, ultimate 

 cells penicellate fascicles. 



Frequent on river stones, in character near (a) but much 

 shorter. 



d. Var. SIMPLICIOR, Eab. 



Dull green, sparingly branched ; the penicellate fascicles 

 very thin. 



e. Var. STJBSIMPLEX, Eab. 



Very sparingly branched, devoid of penicellate fascicles. 



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