Myxophyceae 175 



Alaska. On dripping rocks, much mixed with other algae of a gelatinous 

 nature. Iliuliuk, Unalaska. (Setchell and Lawson). 



327. Nostoc calidarium Wood. Contr. Hist. Fresh-Water Algae North 



America. 34. pi. 2. f. 2. 1872. De Toni. Syll. Algar. 5: 409, 423. 1907. 



Plate VIII. fig. 3. 



Plant mass indefinitely expanded, either membranaceous coriaceous 

 oi- gelatinous, bright or dull olive green or olive brown, irregularly and 

 deeply sinuate, finally neatly laciniate; filaments 2 mic. (?) in diameter, 

 unequal, sometimes flexuously curved but mostly straight and closely joined, 

 occurring in two forms; the one small, with cylindrical cells, scattered 

 heterocysts and diffluent sheaths, if any; the other form very large, with 

 globose or oblong cells and heterocysts not different from the other cells. 



California. In hot springs. Temperature 110-120° and 124-135°. F. 

 Benton's Spring, Owen's Valley, sixty miles southwest from Aurora. 

 (Partz). 



328. Nostoc austinii Wood. Contr. Hist. Fresh-Water Algae North Amer- 



ica. 27. 1872. De Toni. Syll. Algar. 5: 411. 1907. 



Colonies somewhat spherical, small, mostly the size of fish eggs, but 

 reaching the diameter of nearly 4 mm., sometimes very hard, sometimes 

 much softer, with surface often corrugated, brownish or blackish; filaments 

 variously curved, densely entangled or distantly and loosely interwoven, 

 greenish, brownish, lead-colored or yellowish brown; sheaths often dis- 

 tinct in smaller colonies, those in larger ones indistinct or not visible; 

 trichomes 6.5-8.2 mic. in diameter; cells spherical, often in pairs; hetero- 

 cysts equal to diameter of cells or a little larger, spherical, intercalary or 

 terminal, cell contents coarsely granular. 



New Jersey. Growing amidst mosses on rocks. Near Gloucester. 

 (Austin). 



329. Nostoc macrosporum Meneghini. Monographia Nostochinearum ital. 



116. pi. 14. f. 2. 1843. Bornet and Flahault. Revis. des Nostoc. Ann. 



Sci. Nat. Bot. VII. 7: 209. 1888. De Toni. Syll. Algar. 5: 412. 1907. 



Farlow. Notes on the Cryptogamic Flora of the White Mountains. 



Appalachia. 3: 236. 1883. Wolle. Fresh-Water Algae U. S. 284. 1887. 



Bessey, Pound and Clements. Additions to the Reported Flora of the 



State. Bot. Surv. Nebraska. 5: 12. 1901. 



Plate VIII. fig. 4- 



Colonies small, solid, spherical or oblong, blue-green or olive, be- 

 coming brownish; filaments loosely entangled, flexuously curved, or spi- 

 rally rolled; sheaths often distinct, yellowish; trichomes 8-9 mic. in diame- 

 ter, especially cylindrical; cells short, disc-shaped, or equalling the diame- 

 ter in length, closely connected; heterocysts 9-10 mic. in diameter, some- 

 what spherical; gonidia (according to Borzi) "globose, angular from mutual 

 pressure, or globose-compressed, two or three times larger than the cells; 

 wall of gonidium thin, very smooth"; cell contents pale blue-green or 

 olive green. 



