2yg Minnesota Algae 



508. Dichothrix gypsophila (Kuetzing) Bornet and Flahault. Revis. des 



Nostoc. Ann. Sci. Nat. Bot. VII. 3: 377- 1886. De Toni. Syll. Al- 

 gar. s: 642. 1907. 



Wolle. Fresh- Water Algae U. S. 237. pi. 168. f. 5. 1887. (Calothrix 

 gypsophila Kg.). Wolle and Martindale. Algae. Britton's Catalogue 

 of Plants found in New Jersey. Geol. Surv. N. J. 2: 603. i88g. Weed. 



Formation of Travertine and Silicious Sinter by the Vegetation of Hot 

 -Springs. U. S. Geol. Survey. 9th Ann. Report. 665. 1889. Setchell. Notes 

 on Cyanophyceae.— I. Erythea. 4: 88. 1896. Tilden. American Algae. 



Cent. II. no. 200 B. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. 

 Fasc. 12. no. 562. 1899. Collins. Phycological Notes of the late Isaac 

 Holden. — II. Rhodora. 7: 238. 1905. 



Plate XIX. fig. 2. 



Filaments caespitose, scattered or forming a somewhat continuous 

 layer, very often "nestling'' among filaments of Hypheotrichum and 

 I, eptotrichum, and encrusted with calcium carbonate (calareous tufa), 

 15-18 mic. in diameter (in the ultimate branches), about 2 mm. in length, 

 erect, penicillate; upper false branches appressed, included within the com- 

 mon tegument; sheaths thick, lamellose, smooth, orange becoming brown, 

 finally opaque, ocreate; ocreae dilated, truncate, and torn at the apices; 

 trichomes 6-8 mic. in diameter, gradually tapering into a hair; cells equal 

 to or a little longer than the diameter; cell contents green or olive. 



Connecticut. Forming gelatinous yellow masses upon rocks and small 

 stones about the edge of Long Pond, at Lantern Hill, in Ledyard. Septem- 

 ber 1892. (Setchell). Incrusted on limestone, shore of Housatonic River, 

 near Gaylordsville. October 1898. (Holden). New Jersey. Fresh Water. 

 Morris; rocky shores of Lake Hopatcong. (Wolle). Florida. Adams Key. 

 July 1895. (Curtiss.) Wyoming. Forming a finely fibrous sinter, con- 

 sisting of layers one-sixteenth of an inch to half an inch thick, each stratum 

 resembling a very fine thick white fur. In overflow channels of geysers. 

 Upper Geyser Basin, Yellowstone National Park. (Weed). Taken from wall 

 of Excelsior crater. Weed affirms that it is due "to the growth of the little 

 alga — C alothrix gypsophil a — or the young form, Mastigone- 

 ma thermale." Middle Geyser Basin, Yellowstone National Park. June 

 1896. (Tilden). 



509. Dichothrix hosfordii (Wolle) Bornet in Setchell. Notes on Cyanophy- 



ceae. — II. Erythea. 4: 190. 1896. Wolle. Fresh-Water Algae. V. 

 Bull. Torr. Bot. Club. 8: 38. 1881. (Calothrix hosfordii 

 Wolle); Fresh- Water Algae U. S. 239. pi. 169. f. 1-4; pi. 170. f. 3, 

 4. 1887. 



Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 5. no. 215. 1896. 

 Collins. Some Perforating and other Algae on Fresh-Water Shells. Erythea. 

 S: 96. 1897; Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 

 238. 1905. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 29. no. 

 1408. 1907. 



