88 Minnesota Algae 



Canada. Forming a very slippery but firm brownisli black stratum and 

 also scattered among other algae. Warm sulphur spring, Banff, Alberta. 

 June 1901. (Butler and Polley). Minnesota. Twin Lakes, Hennepin 



County. October 1894. (Tilden). Iowa. Slough. Ontario. (Buchanan). 

 South Dakota. In artesian water. Iroquois. September 1897. (Saunders). 

 Nebraska. In salt creek, Lincoln. (Bessey). Wyoming. On surface of 

 slill pool into which overflow runs. Temperature 41° C. Mammoth Hot 

 Springs. July 1896. (Tilden). Overflow of channel of geyser. Temperature 

 49°-54-5° C. Spasmodic Geyser. Upper Geyser Basin. Yellowstone 

 National Park. 1897. (Weed). Utah. Forming a whitish brittle scum 

 in hot water. Bick's Hot Spring, Salt Lake -City, July 1897. (Tilden). 

 Washington. In pools of slightly brackish water. Monroe's Landing, near 

 Coupeville, Whidbey Island. (Gardner). Califortua. (Parish and Mc- 

 Clatchie). Hawaii. Mixed with other algae,' on sides of wet rocks. Laup- 

 ahoehoe, Hawaii. July 1900. (Tilden). 



This species is quite common in both the calcareous and silicious waters 

 of Yellowstone Park. It is generally found with other algae. 



V/T. Spirulina nordstedtii Gomont. Monogr. Oscill. 272. 1893. De Toni. 

 Syll. Algar. 5: 212. 1907. 



Collins. Preliminary Lists of New England Plants. — V. Marine Algae. 

 Rhodora. 2: 43. 1900. ,- 



Plant mass olive green; trichomes 2 mic. in diameter, fragile, twisted 

 into an especially regular spiral S mic. in diameter, the distance between 

 the turns being s mic; cell contents pale blue-green. 



Maine. (Collins). 



178. Spirulina subtilissima Kuetzing. Phyc. Gen. 183. 1843. Gomont. Mon- 



ogr. Oscill. 272. pi. 7. f. 30. 1893. De Toni. Syll. Algar. 5: 212. 



1907. 

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

 Slate. Bot. Surv. Nebraska. 5: 14. 1901. Collins, Holden and Setchell. 

 Phyc. Bor.-Am. Fasc. 23. no. 1103. 1903. Lemmermann. Algenfl. Sand- 

 wich-Inseln. Bot. Jahrb. 34: 619. 1905. 



Plate IV. fig. 47. 



Plant mass mucous, dark green; trichomes .6-.9 mic. in diameter, ag- 

 glutinated, flexuous, twisted into an especially regular spiral 1.5-2.5 mic. in 

 diameter, the distance between the turns being 1.2-2 mic; cell contents 

 very pale green or yellowish. 



Nebraska. In salt creek. Lincoln. (Bessey). California. In outflow 



from a sulphur spring. Mt. Diablo. Contra Costa County. July 1900. (Oster- 

 hout). Hawaii. Washings from marine algae. Laysan Island. 1896-1897. 

 (Schauinsland). 



179. Spirulina tenerrima Kuetzing. Phyc. Gen. 183. 1843. Gomont. Monogr. 



Oscill. 272. 1893. De Toni. Syll. Algar. 5: 213. 1907. 

 Trichomes mixed with other algae,' .4 mic. in diameter, twisted into 

 ail especially regular spiral 1.4-1.6 mic. in diameter, the distance betwe,en 

 the turns being 1 mic; cell contents very pale blue-green. 



