i8o Minnesota Algae 



Arctic Regions. Beechey Island. (Lyall). Port Kenedy. (Walker). 

 Alaska. Fresh water pools. Port Clarence. (Harvey). Greenland. On 

 stones in fresh water streams; in pools of fresh water, Island of Disko. 

 (Lyall). Canada. Freshwater. Cumberland Sound. (Taylor). Pennsyl- 

 vania. Growing in great abundance in very cold, large, limestone spring. 

 Centre County. Summer of 1869. (Wood). Indiana. Attached to the 



stone bottom of a small stream, flowing across University Campus. Jordan 

 Branch. Bloomington. (Brown). Wisconsin. Attached to rocks in water- 

 fall. Burkhardt. September 1899. (Tilden). Illinois. Bowmanville. July. 

 (Johnson and Atwell). Minnesota. On rocks in falls in river. Lester 

 River, Lester Park, Duluth. August 1901. (Tilden). Nebraska. In cul- 

 ture in greenhouse. Lincoln. (Bessey). Montana. "Common at the Falls 

 of the Missouri and in spring water impregnated with lime. In the fall 

 of the year this species is torn from its hold on submerged rocks in the 

 upper Missouri River, rises to the surface and floats to the shore in la,rge 

 numbers. Sometimes watery, hollow specimens, the size of bantam eggs, 

 are picked up." (Anderson and Kelsey). New Mexico. Santa Fe. (Fend- 

 Icr). Nevada. Attached to rocks in running water. Humboldt River, 

 Winnemucca. July 1901. (Griffiths). Mexico. "Found in the aguada 



Chulubmay, nine miles east of Izamal. March." (Millspaugh). West In- 

 dies. On rocks in "Wag Water" and in a trough in running water. Castle- 

 ton, Jamaica. April 1893. (Humphrey). Hawaii. Forming small, black, 

 "shot-like" balls, covering sides of pools in falls and rapids. Head waters 

 of flume (2,300 feet). Pacific Sugar Mill, Hamakua, Hawaii. July 1900. 

 (Tilden). 



337. Nostoc amplissimum Setchell. Notes on Cyanophyceae. III. Erythea. 

 7: so. pi. 2,' 3. f. I, 2. 1899. De Toni. Syll. Algar. 5: 421. 1907. 



Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 12. no. SS8. 1899. 



Plate VIII. fig. 17-19. 



Colonies at first spherical, very early becoming hollow and lobulated, 

 expanding until they become irregular, verrucose, brownish yellow sacs, 

 measuring up to 60x30 cm.; membrane of sack of varying thickness, 2-10 

 mm., composed of one to several layers of jelly in which trichomes are 

 embedded, also containing abundant small lumps of lime; filaments very 

 numerous, arranged somewhat variously, near upper and lower surfaces 

 much contorted, in middle more nearly horizontal and parallel; sheaths 

 of outer filaments conspicuous, wide, brown, those of inner filaments dis- 

 tinct, colorless, usually wanting in case of central filaments; trichomes 

 2-3 mic. in diameter, more or less torulose; cells 3.5-5 mic. in length, de- 

 pressed spherical or short cylindrical; heterocysts usually about 4 mic. in 

 diameter; gonidia 3-4 mic. in diameter, 5-6 mic. in length, ellipsoidal, usu- 

 ally beginning to form in outer layer, wall of gonidium smooth, brown. 



California. On stones in streams. Near Pasadena. May 1896. (Mc- 

 Clatchie). Floating and attached to the sides of a watering trough, sup- 

 plied from an artesian well. Near Hollister. April 1897. (Setchell). 



Dr. Setchell calls attention to the fact that this is the largest species 

 belonging to the Cyanophyceae. 



