Myxophyceae 15 



C Sheaths very thick, opaque, intensely lamellose; plants 10-17 mic. 

 in diameter; cells 4-7 mic. in diameter G. ralfsiana 



2 Sheaths sometimes lamellose; plant mass colorless or dark purple, 



growing in hot water; plants 6-7.8 mic. in diameter; cells 1-2.6 mic. 

 in diameter G. thermalis 



3 Sheaths not lamellose 



(i) Plant mass violet becoming gray or black 

 A Plants 4-8 mic. in diameter; sheaths violet, thick, often opaque; 

 cells 1.8-2.5 mic. in diameter G. ambigua 



B Plants 10-17 mic. in diameter; sheaths violet or rose-colored; 

 cells 3.5 mic. in diameter G. violacea 



(2) Plant mass reddish-orange, dark red or black 

 A Plants 11-24 mic. in diameter; sheaths very thick, soon peeling 

 o£E C. dubia 



B Sheaths intensely blood-red, very wide; cells 3.5-9 mic. in diameter 



G. sanguinea 



26. Gloeocapsa granosa (Berkeley) Kuetzing. Tab. Phyc. i: pi. 36. f. VIII. 



1845-1849. De Toni. Syll. Algar. 5: 53. 1907. 



Wolle. Fresh Water Algae. III. Bull. Torr. Hot. Club. 6: 182. 1877. 

 (Gloeothece granosa Rabenh.). 



Plate I. fig. 13. 



Plant mass compact, gelatinous, somewhat cartilaginous, granular, 

 steel blue, green, olive, or dull yellow, more or less spreading; plants 7-8 

 mic. in diameter, globose or oblong, usually two or four in families 18-60 

 mic. in diameter; sheaths very wide, many times exceeding the lumen of the 

 cell, indistinctly lamellose, colorless or nearly so; cells 3-5 mic. in diameter; 

 cell contents homogeneous or granular, pale blue-green. 



Pennsylvania. Wet rocks. (Wolle). 



27. Gloeocapsa polydermatica Kuetzing. Tab. Phyc. i : pi. 20. 1845-1849. De 



Toni. Syll. Algar. 5:51. 1907. 



Wolle. Fresh-Water Algae U. S. 331. pi. 210. f. 29-31. 1887. Collins. 

 Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver 

 Brook Reservations of the Metropolitan Park Commission, Massachusetts. 

 126. 1896. Setchell and Gardner. Algae of Northwestern America. Univ. 

 Calif. Pub. Bot. i: 179. 1903. 



Plate I. fig. 14. 



Plant mass gelatinous, more or less compact, dull green or dusky olive; 

 plants 3-4.5 mic. in diameter, spherical; sheaths very thick, hyaline, lamel- 

 lose, with numerous concentric firm lamellae; cell contents somewhat 

 homogeneous, blue-green or green. 



Alaska. On dripping rocks. Near Iliuliuk, Unalaska. (Setchell and 

 Lawson). Massachusetts. On dripping rocks. Cascade, Middlesex Fells. 



