Myxophyceae 189 



Gonidia 20 mic. in diameter, spherical. 

 West Indies. Santa Cruz. (Hornemann). 



350. Anabaena Hos-aquae (Lyngbye) Brebisson in Brebisson and Godey. 



Algues des Environs de Falaise. 36. 1835.- Bornet and Flahault. 



Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 228. 1888. De Toni. 



Syll. Algar. S: 441. 1907. 

 WoUe. Fresh Water Algae. III. Bull. Torr. Bot. Club. 6: 183. 1877. 

 (Trichormus incurvus Allm.). Farlow. Notes on Fresh- Water 

 Algae. Bot. Gaz. 8: 225. 1883. Wolle. Fresh-Water Algae U. S. 286. 1887. 

 Bennett. Plants of Rhode Island. 114. 1888. Trelease. The "Working" 

 of the Madison Lakes. Trans. Wis. Acad. Sci. Arts and Letters. 7: 122. pi. 

 10. f. 4. 1889. Wolle and Martindale. Algae. Britton's Catalogue of Plants 

 found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. Saunders. Proto- 

 phyta-Phycophyta. Flora of Nebraska. 18. 1894. Tilden. List of Fresh- 

 Water Algae collected in Minnesota during 1896 and 1897. Minn. Bot. 

 Studies. 2: 27. 1898; American Algae. Cent. III. no. 292. 1898. Fanning. 

 Observations on the Algae of the St. Paul City Water. Minn. Bot. Studies. 

 2: 609. pi. 45. f. 21. 1901. Tilden. American Algae. Cent. VI. no. 576. 1902. 

 Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. 

 Bot. 1 : 192. 1903. Nelson. Observations upon some Algae which cause 

 "Water Bloom." Minn. Bot. Studies. 3: 56. pi. 14. f. 3. 1903. Moore and 

 Kellerman. A Method of Destroying and Preventing the Growth of Algae 

 and Certain Pathogenic Bacteria in Water Supplies. U. S. Dept. Agric. 

 Bureau of Plant Industry. Bull. 64. 20. 1904. Riddle. Brush Lake Algae. 

 Ohio Nat. 5: 268. 1905. Clark. The Holophytic Plankton of Lakes 



Atitlan and Amatitlan, Guatemala. Proc. Biol. Soc. Wash. 21: 98. 1908. 

 Tilden. Notes on a Collection of Algae from Guatemala. Proc. Biol. Soc. 

 Wash-. 21: 155. igo8. Buchanan. Notes on the Algae of Iowa. Proc. 

 Iowa Acad. Sci. 14: 12. 1908. 



Plate IX. fig. 14. 



Plant mass frothy, gelatinous, lubricous, floating, bluish in color; 

 sheaths not present; trichomes 4-8 mic. in diameter, circinate; cells 6-8 mic. 

 in length, compressed spherical; heterocysts a little wider and longer than 

 the cells; gonidia 7-13 mic. in diameter, 20-50 mic. in length; curved, 

 oblique, inequilateral, contiguous to or rarely remote from the heterocysts, 

 often surrounded by a wide gelatinous sheath; wall of gonidium smooth, 

 colorless or yellowish. 



Greenland. (Borgesen). Rhode Island. Very common. (Bennett). 

 Nevy Jersey. Common on stagnant fresh water. (Wolle). District of Colum- 

 bia. Washington. (Moore and Kellerman). Ohio. Brush Lake, Cham- 

 paign County. Fall of 1902. (Riddle). Wisconsin. Forming a part of a 

 greenish yellow scum which occurs every season in greater or less quantity 

 on Third and Fourth Lakes (Mendota and Monona) during the hot weather 

 of summer. (Trelease). Minnesota. (Farlow). Floating in abundance on 

 surface of water. Cedar Lake, Hennepin County. October 1897. (Fanning 

 and Humphrey). City water supply, St. Paul. (Fanning). Forming a pale, 

 bluish green scum. Spring Park, Lake Minnetonka, Hennepin County. 

 October 1901. (Nelson). Iowa. "One of the most common of the con- 



