Myxophyceae 99 



England. 22: 430. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. 

 Fasc. 3. no. 103. 1895. Tilden. List of fresh-water Algae collected in 

 Minnesota during 1896 and 1897. Minn. Bot. Studies. 2: 28. 1898. Collins. 

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

 42. 1900. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 23. no. 

 1105. 1903. Setchell and Gardner. Algae of Northwestern America. Univ. 

 Calif. Pub. Bot. i: 184. 1903. Tilden. Notes on a Collection of Algae 

 from Guatemala. Proc. Biol. Soc. Wash. 21: 154. 1908. Tilden. American 

 Algae. Cent. VII. Fasc. i. no. 644. 1909. 



Plate IV. fig. 66. 



Plant mass up to 3 cm. in thickness, slimy, expanded, lamellose, the 

 upper layers dull green, the lower layers whitish; filaments flexuose, dense- 

 ly entangled; sheaths narrow, papery, finally diffluent into a tenaceous 

 mucus and becoming agglutinated; trichomes 2-2.5 mic. in diameter, straight, 

 not constricted at joints; apex of trichome not tapering; apical cell ro- 

 tund; calyptra none; cells 3.3-6.7 mic. in length; transverse walls marked 

 by two or four protoplasmic granules; cell contents blue-green. 



Alaska. On dripping timber of old mill. Sitka. (Setchell and Lawson). 

 Canada. Forming a thick, stratified mass. Warm sulphur spring. Banff, 

 Alberta. June 1901. (Butler and Polley). Rhode Island. "Forming verdi- 

 gris-green gelatinous sheaths, later becoming chartaceous, on stones and 

 on leaves of Ruppia maritimain brackish water. Watch Hill Pond, 

 Watch Hill. Septemher 1892." (Setchell). Connecticut. (Collins). 



Minnesota. In arm of Mississippi River (old channel). St. Paul Park. 

 October 1897. (Freeman). Gulf of California. In thermal water at 75°. 

 "Du ruisseau de I'Azufres au pied du volcan de las Virgenes.'' Central 

 America. Associated with Nodularia harveyana. Laguna, Lake 

 Amatitlan, Guatemala. Altitude 395° feet. February 1905. (Kellerman). 



196. Phormidium subuliforme Gomont. Monogr. Oscill. 189. pi. 4. f. 26. 



1893. De Toni. Syll. Algar. 5: 230. 1907. 

 Bessey, Pound and Clements. Additions to the Reported Flora of the 

 State. Bot. Surv. Nebraska. 5: 12. 1901. 



Plate IV. fig. 67. 



Plant mass lamellose, yellowish green; sheaths diffluent into an amor- 

 phous, gelatinous mucus; trichomes 2-2.8 mic. in diameter, straight, con- 

 stricted at joints; apex of trichome gradually tapering, bent or twisted, 

 not capitate; apical cell more or less acute-conical; calyptra none; cells 

 6-8 mic. in length; transverse walls distinct; cell contents homogeneous or 

 coarsely granular, blue green. 



Nebraska. In aquaria. Lincoln. (Bessey). 



197. Phormidium incrustatum (Naegeli) Gomont in Bornet and Flahault. 



Sur quelques plantes vivant dans le test calcaire des Mollusques, in 

 Bull. Soc. Bot. France. 36: 154. 1889; Monogr. Oscill. 190. pi. 4- i- 

 27. 1893. De Toni. Syll. Algar. 5: 230. 1907. 

 Tilden. American Algae. Century II. no. 183. 1896; List of fresh-water 



