66 



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

 Bot. i: 183. 1903. Collins. Phycological Notes of the late Isaac Holden. 

 — II. Rhodora. 7: 235. 1905. Riddle. Brush Lake Algae. Ohio Nat. 5: 

 268. 1905. Brown. Algal Periodicity in certain ponds and streams. Bull. 

 Torr. Bot. Club. 35: 243, 247. 1908. Collins, Holden and Setchell. Phyc. 

 Bor.-Am. Fasc. 31. no. 1503. 1908. Buchanan. Notes on the Algae of 

 Iowa. Proc. Iowa Acad. Sci. 14: 14. 1908. Tilden. American A'gae. Cent. 

 VII. Fasc. I. no. 648. 1909. 



Plate IV. fig. 6. 



Plant mass dark blue-green; trichomes 11-20 mic. in diameter, crowded, 

 straight (in dried specimens rigid and fragile), not constricted at joints; 

 apex of trichome straight, not at all or scarcely tapering, not capitate; 

 apical cell showing a convex, somewhat thickened outer wall; cells 2-5 mic. 

 in diameter; transverse walls frequently granulated; cell contents blue- 

 green or olive. 



Canada. Humber River, Toronto. (Mackenzie). United States. (Wolle). 

 Maine. In fresh water. Mount Desert Island. (Holden). Massachusetts. 

 Newton. (Farlow). Charles River, Newton; on wharves, Nantucket; in 

 claypit, Glenwood, Medford, April 1892. (Collins). Rhode Island. (Col- 

 lins). Connecticut. On sandy bottom and floating in fresh water ditch. 

 May 1892; Berkshire Mill Pond (brackish), Bridgeport, May 1894; stream, 

 Stratford; Great Falls of the Housatonic; ditch below Factory Pond, 

 floating and attached to plants; Berkshire Mill Pond; forming a dark 

 purple stratum on plants in running water, Pequonnock River, below Fac- 

 tory Pond Dam. (Holden). New York. Brooklyn water supply. Decem- 

 ber and February. (Jelliffe). New Jersey. Stapleton and Tomkinsville, 

 Staten Island. (Pike). Frequent, on wet earth. (Wolle). Texas. 1902. 

 (Fanning.) Ohio. Brush Lake, Champaign County. 1902. (Riddle). In 

 washings of stones and of plants growing in the lake. Put-in-Bay, Lake 

 Erie. (Snow). Indiana. Faris Pond, Fees Pond, Monon Pond, Jordan 

 Branch. Near Bloomington. December until May. (Brown). Minnesota. 

 Growing mostly beneath surface of water. Current very swift. State Fish 

 Hatcheries, St. Paul. September 1894. (Tilden). In rapidly running water, 

 forming brown coating on decayed leaves. Minnehaha Creek, above the 

 Falls, Minneapolis. October 1901. (Hone). Iowa. In a sulphur spring, 

 Iowa Falls. June 1904. (Gardner). Very common. Iowa City. (Hobby). 

 Fayette. (Fink). On damp earth, forming a thin coating. Ames. (Bessey, 

 Buchanan). Moist earth; floating in Hewitt's Pond, Eagle Grove; on 

 moist soil in the greenhouse. Ames. (Buchanan). Nebraska. Common 

 on damp earth, forming a blue-green coating. (Saunders). Washington. 

 Floating on ditches of slightly brackish water. La Conner, Skagit Couxity; 

 Whidbey Island. (Gardner). 



Var. badia Tilden. American Algae. Cent. II. no. 188. 1896. De Toni. 

 Syll. Algar. 5: 157. 1907. 



Plant mass forming a thin scum on rocks, afterwards breaking loose 

 and floating on surface of water, brownish; trichomes 9.5 mic. in diameter; 

 cells 5-9.5 mic. in length; cell contents drab or light brown. 



