THE GREEN ALGAE OF NORTH AMERICA 353 



ally connate at the base ; filaments 63-70 p. diam. below, ramuli 

 20 //. ; cells 8-15 diam. long. Minn. 



C. glomcrata var. callicoma forma Minnesotana Brand in 

 Tilden, American Algae, No. 538; P. B.-A., No. 1379. 

 Glomerules not conspicuous, branches seldom connate ; fila- 

 ments 70-80/1 diam., ramuli 17 /x ; cells 5-8 diam. long.- Minn., 

 California. 



47. C. FRACTA (Dillw.) Kiitzing, 1843, p. 263; 1854, PI. I,. ; 

 Wolle, 1887, p. 124; P. B.-A., Nos. 120, 816, 1281, 1282. 

 Fronds forming loose, floating masses, usually of a dark green 

 color ; branching irregular, filaments much bent and curved ; 

 main filaments 60-120 p. diam., cells 1-3 diam. long ; ramuli 20- 

 40 p. diam., cells 3-6 diam. long; cells seldom cylindrical, 

 mostly ovoid, clavate or irregular ; fruiting cells never terminal. 



A species of world-wide distribution, taking on innumerable 

 shapes which have received names as forms, varieties and 

 species ; one of these is retained here as a species in the same 

 way as four are retained in connection with C. glomcrata, but 

 with much doubt as to their representing distinct specific types. 



Forma GOSSYPINA (Kiitz.) Rabenhorst, 1868, p. 335 ; Algen, 

 No. 2576; Wolle, 1887, p. 125 ; Tilden, American Algae, No. 

 141. Filaments slender, sparingly branched; forming dense, 

 interwoven, silky masses. Pa., Idaho. Europe. 



Form SUBSIMPLEX Kiitzing, 1845, p. 218. Filaments very 

 slightly branched ; easily mistaken for a Rhizodonium . Mass. 



Europe. 



Forma RIGIDULA (Kiitz.) Rabenhorst, 1868, p. 335. Fila- 

 ments stout and stiff, loosely branched. Conn. Europe. 



Forma REFLEXA Collins, P. B.-A., No. 1194. Main branches 

 stout, flexuous ; branches of higher orders patent or reflexed, 

 often in secund series. Cal. 



Forma STREPENS (Ag.) Rabenhorst, 1868, p. 335 ; C. strepens 

 Kiitzing, 1854, PI. XLVIII, fig. 2 ; C. fracta var. calcarea Til- 

 den, American Algae, No. 142. Branching irregular; main 

 filaments 90-125 /x. diam.; ramuli 25-40 p. ; cells cylindrical or 

 swollen, varying in length from i to 6 diam. in the same fila- 

 ment ; the whole plant more or less incrusted with lime. So. 

 Dakota. , So. Europe. 



48. C. OLIGOCLONA Kiitzing, 1845, p. 218; 1854, PI. UV. 

 Filaments sparingly branched, pale or dirty green ; main fila- 

 ments mostly dichotomous, secondary filaments elongate, beset 

 with short, mostly unicellular ramuli ; cells cylindrical to 



