Myxophyceae loi 



199. Phormidium oorium (Agardh) Gomont. Essai Class. Nostocacees 



homocystees. Morot, Journ. de Bot. 4: 355. 1890; Monogr. Oscill. 



192. pi. 5. f. I, 2. 1893. De Toni. Syll. Algar. 5: 235. 1907. 

 Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook 



and Beaver Brook Reservations of the Metropolitan Park Commission, 

 Massachusetts. 127. 1896. Collins, Holden and Setchell. Phyc. Bor.-Am. 

 Fasc. 7. no. 304. 1897. Tilden. American Algae. Cent. IV. no. 399. 1900. 

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

 Rhodora. 2: 42. 1900. Bessey, Pound and Clements. Additions to the 

 Reported Flora of the State. Bot. Surv. Nebraska. 5: 13. 1901. Setchell 

 and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 

 185. 1903. Collins. Phycological Notes of the late Isaac Holden. — II. 

 Rhodora. 7: 236. 1905. 



Plate IV. fig. 71, 72. 



Plant mass widely expanded, membranaceous, leathery, dark blue-green 

 or black; filaments elongate, more or less flexuous, densely entangled; 

 sheaths thin, papery, or diffluent into an amorphous mucus; trichomes 

 3-4.5 mic. in diameter, not constricted at joints; apex of trichome straight, 

 briefly tapering, not capitate; apical cell obtuse conical; calyptra none; 

 cells 3.4-8 mic. in length; transverse w^alls not granulated, usually con- 

 'ST'icuous; cell contents sometimes granular, blue-green. 



Greenland. ■ (Borigesen). Massachusetts. On cliff. Middlesex Fells. 

 (Collins). Connecticut. On stonework of dam at R. R. crossing. Bruce's 

 Brook; on woodwork of dam, Island Brook, below Housatonic R. R.; 

 on stonework of dam at Moody's Pond, May 1894, Bridgeport. (Holden). 

 South Carolina. On rocks and timbers under dam at mill. Chester County. 

 May 1898. (Green). Nebraska. In ponds. South Bend, Long Pine. (Bes- 

 sey, Pound and Clements). 



200. Phormidium papyraceum (Agardh) Gomont. Essai Class. Nostocacees 



homocystees. Morot. Journ. de Bot. 4: 3SS- 1890; Monogr. Oscill. 



193. 1893. De Toni. Syll. Algar. 5: 1907. 



Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 14. no. 653. 1900. 

 Tilden. Collection of Algae from the Hawaiian Islands. Haw. Almanac and 

 Annual for 1902. 112. 1901; American Algae. Cent. V. no. 493. 1901. Col- 

 lins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 21. no. 1004. 1903. 



Plate IV. fig. 73, 74- 



Plant mass expanded, glistening, thin, leathery, fraigile when dried, 

 dark green; filaments elongate, strongly flexuous, very densely entangled; 

 sheaths thin, papery, sometimes diffluent; trichomes 3-5 mic. in diameter, 

 not constricted at joints; apex of trichome straight, briefly tapering, not 

 capitate; apical cell obtuse-conical; calyptra none; cells 2-4 mic. in length; 

 transverse walls usually conspicuous, not granulated; cell contents some- 

 times granular, blue-green. 



Maine. On stones at low water mark, outlet of fresh water brook, but 

 within influence of tide. Cape Rosier. July 1901. (Collins). Massachusetts. 

 In brook on stones under falling water. Medford. April 1896. (Collins). 



