THE GREEN ALGAE OF NORTH AMERICA 75 



6. Lower cells seldom as long as broad ; ratnuli tapering, thorn-like. 



4. S. subuligerum. 

 6. Lower cells usually longer than broad ; ramuli short-pointed. 



i. 5". lubricum. 



7. Lower cells 2-5 diam. long. i. S. lubricum var. varium. 



7. Lower cells 3-8 diam. long. 8. 



8. Ramuli pointed. 2 . s. amoenum. 



8. Ramuli setiform. 3 . S. flag ellifer urn. 



9. Filaments short, tufted. Ia 



9. Filaments more elongate. 



10. Of thermal waters. 7 . s. thcrmale. 



10. Of ordinary temperatures. JIm 



ii. Tips obtuse or short-pointed. 8. S. nanum. 



ii. Tips attenuate or setiferous. 12. 



12. Ramuli scattered. 



'3- 



12. Ramuli densely fasciculate. 10. S. glomeratum. 



13. Main filaments 7-9 //. diam. 9. S. aestivale. 



13. Main filaments 4-6 /j. diam. 14. S. minus. 



14. Floating. I2 . 5. stagnatile. 



14. Attached. I ^ < 



15. Main filaments 10 M diam. or less. 16. 



15. Main filaments 10 /* diam. or more. 17. 



16. Cells of main filaments 6-10 M diam., usually 4-6 diam. long, some- 

 times 12 diam. 5. longearticulatum. 

 16. Cells of main filaments 5^7 p. diam., 2-5 diam. loug. 



5*. attenuatum. 

 17. Filaments 10-12 /u, diam., cells except in the main axis seldom over 



i diam. long. 2. 5". amoenum forma biforme. 



17. Filaments 12-18 M diam. 18. 



18. Main filaments with cells 1-2 diam. long, moniliforni. 



5". autumnale. 

 18. Main filaments with cells 3-10 diam. long, cylindrical. 



13. S. subsecundum. 

 Page 302, after description of S. MINUS, add, 



S. LONGEARTICULATUM (Hansg.) Heering in Pascher, 1914, 

 p. 71, fig. 95; S. falklandicum var. longearticulatum Hansgirg, 

 1886, p. 65, fig. 27; S. falklandicum Wittr. & Nordst., Alg. 

 Exsicc., No. no. Main filaments 6-10 /x diam., cells 4-6, occa- 

 sionally 12 diam. long, cylindrical ; branching sparingly below, 

 freely above ; branches somewhat narrower and with relatively 

 shorter cells ; chromatophore a narrow band at the middle of 

 cell. Utica, Ohio, Transeau. Europe. 



Page 305. Add, Lemmermann in Pascher, 1915, p. 47, trans- 

 fers CHLOROSPHAERA LACUSTRIS Snow and C. PARVULA Snow 

 to the following genus of Tetrasporales. 



