250 Minnesota Algae 



Bull. Torr. Bot. Club. 6: 183. 1877. (Sirosiphon coralloides Kg., S.^ 

 lacu'stris Rab.) ; Fresh-Water Algae U. S. 270. pi. 191. f. 21; pi. 192. f. 

 9-12. 1887. WoUe and Martindale. Algae. Britton's Catalogue of Plants 

 found in New Jersey. Geol. Surv. N. J. 2: 605. 1889. West and West. On 

 some Freshwater Algae from the West Indies. Journ. Linn. Soc. Bot. 30. 

 273. 1895. Setchell. Notes on Cyanophyceae. — I. Erythea. 4: 88. 1896; 

 Notes on Cyanophyceae. — II. Erythea. 4: 191. 1896. 



Plate XV. fig. 21. 



Plant mass expanded, caespitose or crustaceous, somewhat mucous, 

 brownish or black; filaments 40-70 mic. in diameter, 1-2 mm. in length, erect 

 from a decumbent base, irregularly branched; branches 45 mic. in diameter, 

 straight or bent, branched on upper side, all bearing hormogones; sheaths 

 thick, lamellose, yellowish brown; cells 15-18 mic. in diameter; heterocysts 

 numerous, collateral; hormogones 18 mic. in diameter, 45 mic. in length, 

 solitary or in series. 



Vermont. Wet rocks. Mt. Mansfield. (Wolle). Connecticut. In small 

 quantity in Long Pond, Lantern Hill, Ledyard. (Setchell). New Jersey. 

 On stones constantly washed by the waves, along the rocky shores of 

 Green Pond, Morris. (Wolle). On dry rocks and on moist rocks. (Austin.) 

 South Carolina. Growing on the bark ofTaxodiumdistichum. Aiken. 

 (Ravenel). West Indies. On trees. Summit of Trois Pitons (4500 feet). 

 Dominica. (Elliott). 



456. Stigonema mamillosuni (Lyngbye) Agardh. Syst. Algar. 42. 1824. 



Bornet and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 



S: ^^. 1887. De Toni. Syll. Algar. 5; 587. 1907. 

 Wood. Contr. Hist. Fresh-Water Algae North America. ^^. 1872. 

 Farlow. Marine Algae New England. 40. 1882; Notes on the Cryptogamic 

 Flora of the White Mountains. Appalachia. 3: 236. 1883. Collins. Algae. 

 Rand and Redfield's Flora of Mount Desert Island, Maine. 247. 1894; Algae. 

 Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook 

 Reservations of the Metropolitan Park Commission, Massachusetts. 128. 

 1896. Collins, Holden and Setchell. Phy. Bor.-Am. Fasc. 8. no. 356. 1897. 

 Collins. Algae of the Flume. Rhodora. 6: 230. 1904; Phycological Notes of 

 the late Isaac Holden. — II. Rhodora. 7: 237, 243. 1905. 



Plate XV. fig. 22. 



Plant mass cushion-like, woolly, up to 12 mm. in thickness; filaments 

 up to 65 mic. in diameter, erect, rigid, interwoven, very much branched at 

 the base; branches 45-50 mic. in diameter, gradually tapering at the ends, 

 erect, spreading, with numerous branchlets; some branchlets sterile, long 

 and thick, others bearing hormogones, mammilliform, short, spreading, 

 shorter than the diameter of the branch, 24 mic. in diameter; sheaths thick, 

 lamellose, often torulose, yellowish brown; hormogones short, 15 mic. in 

 diameter, 45-50 mic. in length; heterocysts collateral. 



Newfoundland. On submerged stones in a pond at the foot of Windsor 

 Lake, near St. John's. July 1897. (Holden). Maine. On rocks in outlet of 

 Hadlock Lower Pond. (Holden). New Hampshire. On submerged stones 



