Myxophyceae 105 



Plate V. fig. 9, 10. 



Plant mass moderately expanded, papery or thick, attached at base,, 

 floating, dark blue-green, when dried dark lead-colored; sheaths usually not 

 present; trichomes 4.5-9 mic. in diameter, elongate, more or less flexuous, 

 not constricted at joints, straight or somewhat spiral near the extremities, 

 agglutinated by an amorphous mucus; apex of trichome gradually tapering, 

 especially capitate; apical cell obtuse truncate, showing a somewhat' hemi- 

 spherical calyptra; cells 3-7 mic. in length; transverse walls marked by 

 double rows of granules; cell contents blue-green. 



Arctic Regions. Dried up pool. Distant Cape, Discovery Bay. (Dickie). 

 Alaska. Floating or attached to wpod in streams or on the ground. Glacier 

 Valley, Unalaska. (Lawson). Juneau. (Setchell and Lawson). Massachu- 

 setts. (Farlow, Collins). Rhode Island. (Collins). Connecticut. Stra- 

 tum adhering to rocks in shoal running water. Great Falls of the Housa- 

 tonic, below Lovers' Leap. July. Nev7 York. On stones and earth in 

 water flowing from a spring. Ithaca. April 1895. (Atkinson). Texas. 1902. 

 (Fanning). Wisconsin. In trough. Osceola. August 1895. (Tilden). 



Minnesota. On sides of wooden tub. Long Lake, Hennepin County. Sep- 

 tember 189s. (Tilden). Hawaii. In running water in trough from rice 

 field. Peninsula, Pearl City; on bottom of irrigating ditch in sugar cane 

 field, Ewa Plantation, Oahu, June 1900. (Tilden). 



208. Phormidium calidum Gomont. Essai Class. Nostocacees homocystees. 



Morot. Journ. de Bot. 4: 353. 1890; Monogr. Oscill. 202. pi. 5. f. 

 16. 1893. De Toni. Syll. Algar. 5: 246. 1907. 

 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 28. no. 13S3. 1907. 



Plate V. fig. II. 



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

 trichomes 6-8 mic. in diameter, parallel, somewhat straight, not constricted 

 at joints, agglutinated by an amorphous mucus; apex of trichome straight, 

 scarcely tapering, very slightly capitate; apical cell showing an oblique, 

 depressed conical calyptra; cells 3-8 mic. in length; transverse walls not 

 granulated; cell contents dull blue-green. 



California. Forming a thin layer on rocks. Stow Lake, Golden Gate 

 Park, San Francisco. May 1906. (Gardner). 



209. Phormidium subfuscum Kuetzing. Phyc. Gen. 195. 1843. Gomont. 



Monogr. Oscill. 202. pi. 5. f. 17-20. 1893. De Toni. Syll. Algar. 5: 



247. 1907. 

 WoUe. Fresh-Water Algae. U. S. 300. pi. 201. f. 11-13. 1887. [L. m e m- 

 branacea (Kg.) Thur.]. Collins, Holden and Setchell. Phyc. Bor.- 

 Am. Fasc. 13. no. 605. 1899. 



Plate V. fig. 12-15. 



Plant mass widely expanded, pannose, thin, lamellose, dark green or 

 dark olive; filaments straight, fragile, short, parallel, agglutinated; sheaths 

 diffluent into a lamellose mucus; trichomes 5.5-11 mic. in diameter, not 

 constricted at joints; apex of trichome straight, capitate, more or less briefly 



