Myxophyceae 279 



Plate XIX. fig. 3. 



Plant mass olivaceous; filaments 25-28 mic. in diameter; sheaths wide, 

 distinctly lamellose, yellow towards the base, colorless and hyaline towards 

 the end; trichomes 10-12 mic. in diameter, aggregated, subdichotomously 

 branched, bulbously inflated at the bases of the branches; branches flagel- 

 liform, tapering to a fine, colorless hair point; cells four or five times short- 

 er than their diameter; heterocysts depressed hemispherical ("skull-cap" 

 shaped), light blue in color. 



Vermont. Charlotte. (Hosford). Massachusetts. On pebbles. Shores 

 of Pranker's Pond, Saugus. September 1893; epiphytic on flowering plants 

 ir: shallow water, Herring Pond, Eastham, August 1907. (Collins). Con- 

 necticut. On smooth red sandstone in running water. Wintergreen Falls, 

 Hampden, near New Haven. November 1891. (Setchell). On stones on 

 border of pool below Factory Pond, Pequonnock River. June, July, October, 

 November. Bridgeport. (Holden). Growing on outside surface of Unio 

 shells. Twin Lakes, Salisbury, Litchfield County. (Setchell and Holden). 

 New York. Growing upon submerged stones. Lake George. October 1892. 

 (Jelyffe). Michigan. Ann Arbor. (Johnson^ 



510. Dichothrix rupicola Collins. Notes on Algae. — IV. Rhodora. 3: 290. 



1901. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 20. no. 

 958. 1902. De Toni. Syll. Algar. 5: 644. 1907. 



Plant mass caespitose, i mm. in thickness; filaments 15-22 mic. in 

 diameter, erect, penicillate, branched; ultimate branches flexuous, divaricate, 

 acute; sheaths lamellose, yellow brown with dilated and lacerate ocreation 

 near the tip; trichomes 7-9 mic. in diameter, terminating in a hair; cells 

 about equal to the diameter in length; heterocysts basal; cell contents blue- 

 green to pale olive. 



Maine. Forming a coating on sloping rocks, exposed to the full force 

 of the surf. Pemaquid Point. July 1901. (Collins). 



511. Dichothrix fucicola (Kuetzing) Bornet and Flahault. Revis. des Nos- 



toc. Ann. Sci. Nat. Bot. VII. 3: 379- 1886. De Toni. Syll. Algar. 



S: 644- 1907. 

 Maze and Schramm. Essai Class. Algues Guadeloupe. 32. 1877. (M a s- 

 tichonema sargassi Crouan). Murray. Catalogue of the Marine 

 Algae of the West Indian Region. Journ. of Bot. 27: 261. 1889. 



Plant mass caespitose, made up of penicillate, olive green fascicles, 

 5-8 mm. in height; filaments- 20-30 mic. in diameter (in the ultimate 

 branches), erect, rigid; false branches appressed, strict, fastigiate, included 

 for some distance within the common tegument; sheaths close, thin, 

 uniform, hyaline or yellowish; trichomes 17-22 mic. in diameter, ending in 

 a long hair; upper cells quadrate or one-half as long as wide, lower cells 

 two or three times longer than wide; cell contents pale green; heterocysts 

 basal and intercalary. 



West Indies. Guadeloupe. (Maze). 



