Myxophyceae 169 



similar in form, cylindrical, 6-14 mic. in length; heterocysts somewhat 

 spherical or oblong, 6-7 mic. wide, 6-14 mic. long; gonidia 6-8 mic. in 

 diameter, 14-19 mic. long, elliptical or oblong-cylindrical; wall of gonidia 

 smooth, transparent or yellowish. 



Michigan. Growing over grass and moss, on wet clay bank, forming 

 reddish-brown gelatinous masses, irregularly lobed and fusing into layers. 

 Ann Arbor. September 1892. (Johnson). Minnesota. On wet rocks. Min- 

 nehaha Falls, Minneapolis. August 1883. (Farlow). West Indies. Guade- 

 loupe. (Maze). 



319 B. Nostoc gelatinosum Schousboe in Bornet. Deuxieme Note sur les 

 Gonidies des Lichens. Ann. Sci. Nat. Bot. V. 19: 318. 1874. Bornet 

 and Flahault. Revis. des Nostoc. VII. 7: 199. 1888. De Toni. Syll. 

 Algar. s: 399. 1905. 



Plate VII. fig. II. 



Colonies more than a centimeter in diameter, gelatinous, irregularly ex- 

 panded, buUate-tubercuIate, brownish; filaments flexuous, loosely entangled; 

 sheaths near the outside of colony distinct, those in the interior hyaline and 

 confluent; trichomes 4 mic. in diameter; cells 5-10 mic. in length, oblong- 

 cylindrical; heterocysts $ mic. in diameter, 6-10 mic. in length, elliptical; 

 gonidia 6-8 mic. in diameter, 8-14 mic. in length, with truncate apices, 

 pale brownish in color; wall of gonidium furnished with minute spines. 



Minnesota. With Anthoceros on bank of ditch. Near Minneapolis. 

 September 1904. (Hillesheim). 



320. Nostoc muscorum Agardh. Dispositio. Algar. Sueciae. 44. 1812. Bornet 

 and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 200. 

 1888. De Toni. Syll. Algar. 5: 400. 1907. 



Dickie. In Hooker, J. D. An Account of the Plants collected by Dr. 

 Walker in Greenland and Arctic America, etc. Journ. Linn. Soc. Bot". 5: 

 86. 1861; Notes on a collection of Algae procured in Cumberland Sound 

 by Mr. James Taylor, etc. Journ. Linn. Soc. Bot. 9: 241. 1867. Farlow. 

 Notes on the Cryptogamic Flora of the White Mountains. Appalachia. 3: 

 236. 1883. Wolle. Fresh-Water Algae U. S. 282. pi. 197. f. 35. 1887. 



Collins. Algae of Middlesex County. 163. 1888. (Also N. collinum). 

 Anderson and Kelsey. Common and conspicuous Algae of Montana. Bull. 

 Torr. Bot. Club. 18: 144. 1891. Saunders. Protophyta-Phycophyta. Flora 

 of Nebraska. 18. 1894. Tilden. American Algae. Cent. IV. no. 394. 1900. 

 West and West. A Further Contribution to the Freshwater Algae of the 

 West Indies. Journ. Linn. Soc. Bot. 34: 288. 1898-1900. Tilden. American 

 Algae. Cent. VI. no. 580. 1902. Setchell and Gardner. Algae of North- 

 western America. Univ. Calif. Pub. Bot. i: 190. 1903. Collins, Holden 

 and Setchell. Phyc. Bor.-Am. Fasc. 23. no. mo. 1903. Collins. Algae of 

 the Flume. Rhodora. 6: 230. 1904; Phycological Notes of the late Isaac 

 Holden. — II. Rhodora 7: 242. 1905. Collins, Holden and Setchell. Phyc. 

 Bor.-Am. Fasc. 25. no. 121 1. 1905. Buchanan. Notes on the Algae of Iowa. 

 Proc. Iowa Acad. Sci. 14: 11. 1908. 



