I04 Minnesota Algae 



neither tapering nor capitate; apical cell rotund, with outer membrane 

 slightly thickened; cells 1.5-2.7 mic. in length; transverse walls rarely gran- 

 ulated, occasionally obscured by protoplasmic granules; cell contents granu- 

 lar, blue-green. 



Massachusetts. Forming a coating on stones and algae in ditch in salt 

 marsh. Near Linden station. Revere. October 1892. (Collins). Minnesota. 

 On bottom of wooden trough through which very cold spring water flows 

 with a swift current. State Fish Hatcheries, St. Paul. September 1895. 

 (Tilden). Nebraska. In aquaria. Lincoln. (Bessey, Pound and Clements). 

 Washington. Growing on a submerged log. Green Lake, Seattle. (Gardner). 



205. Phormidium submembranaceum (Ardissone and Straflorello) Gomont. 



Monogr. Oscill. 200. pi. 5. f. 13. 1893. De Toni. Syll. Algar. 244. 

 1907. 



Collins, Holden and Setchell. Phyc. Bor-Am. Fasc. 24. no. 1162. 1904. 



Plate V. fig. 6. 



Plant mass membranaceous, leathery, dark green, sheaths not present; 

 trichomes 5 mic. in diameter, constricted at joints, densely tangled, ag- 

 glutinated by an abundant amorphous mucus; apex of trichome straight, 

 gradually tapering, capitate; apical cell showing a depressed-conical calyp- 

 tra; cells somewhat quadrate, 4-10 mic. in length; cell contents homoge- 

 neous, blue-green. 



California. Forming a thick layer on plants just below water mark. 

 Alameda. September 1903. (Osterhout and Gardner). 



206. Phormidium laysanense Lemmermann. Algenfl. Sandwich.-Inseln. Bot. 



Jahrb. 34: 619. pi. 7. f. 4, 5. 1905. De Toni. Syll. Algar. 5: 245. 1907. 

 Plate V. fig. 7, 8. 



Filaments 5-6 mic. in diameter; sheaths hyaline; trichomes 4-4.5 mic. 

 in diameter, irregularly curved, very rarely straight, not constricted at joints; 

 apex of trichome straight, gradually tapering; apical cell capitate; cells 

 4-11 mic. in length; transverse walls not granulated; cell contents blue-green. 



Hawaii. On Turbinaria. Laysan. 1896-97. (Schauinsland). 



207. Phormidium favosum (Bory) Gomont. Monogr. Oscill. 200. 1893. 



De Toni. Syll. Algar. 5: 245. 1907. 

 Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. 

 Soc. Bot. 17: 8. 1880. (Hypheothrix obscura Dickie). Collins, 

 Holden and Setchell. Phyc. Bor.-Am. Fasc. 3. no. 201. 1895. Tilden. List 

 of Fresh-Water Algae collected in Minnesota during 1895. Minn. Bot. 

 Studies, i: 599. 1896; American Algae. Cent. IL no. 185. 1896. Collins. 

 Preliminary List of New England Plants.— V. Marine Algae. Rhodora. 2: 

 42. 1900. Tilden. Collection of Algae from the Hawaiian Islands. Haw. 

 Almanac and Annual for 1902. 112, 1901; American Algae. Cent. V. no. 

 494. 1901. Setchell and Gardner. Algae of Northwestern America. Univ. 

 Calif. Pub. Bot. i: 186. 1903. Collins. Phycological Notes of the late 



Isaac Holden.— II. Rhodora. 7: 236. 1905. Tilden. American Algae. Cent. 

 VII. Fasc. I. no. 639. 1909. 



