210 Minnesota Algae 



joints; apical cell rotund; cells 2-2.5 mic^ in length; transverse walls not 

 granulated. 



Maine. In the gelatine of a small N o s t o c, growing in a watering 

 trough by the side of the road from Seal Harbor to Jordan Pond, Mount 

 Desert. July 1900. (Collins). New Hampshire. In a gelatinous mass on 

 a wet cliflf. Wanalancet Falls, Tamworth. August 1903; with other algae in 

 masses of translucent gelatine, on walls of the "Flume," September 1904. 

 (Collins). West Indies. Among Gloeocapsa quaternata. Bath, 

 Jamaica. July 1900. (Pease and Butler). Hawaii. In hot water. Kilauea, 

 Hawaii. (Schauinsland). 



386. Plectonema roseolum (Richter) Gomont. Monogr. Oscill. 122. pi. i. 



f. 9, 10. 1893. De Toni. Syll. Algar! 5: 494. 1907. 

 Setchell and Gardner. Algae of Northwestern America. Univ. Calif. 

 Pub. Bot. i: 188. 1903. 



Plate XL fig. 8. 



Plant mass gelatinous, rose-colored, when dried becoming papery, 

 adhering to the paper; filaments densely entangled, strongly tortuous and 

 abundantly branched, sometimes less tortuous and sparingly branched; 

 false branches solitary or in pairs; sheaths colorless, usually thick, firm, 

 irregular in outline; trichomes 1.2-1.8 mic. in diameter, not constricted at 

 joints; apical cell rotund; transverse walls marked by two protoplasmic 

 granules; cell contents very pale rose-color. 



Alaska. On dripping rocks. West shore of Amaknak Island. Bay of 

 Unalaska. (Setchell and Lawson). 



387. Plectonema golenkinianum Gomont. Sur quelques Oscillariees Nou- 



velles. Bull. Soc. Bot. de France. 46: 35. pi. i. f. 11. 1899. De Toni. 

 Syll. Algar. 5: 494. 1907. 

 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 13. no. 603. 1899. 

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

 dora. 2: 42. 1900; Notes on Algae. — VI. Rhodora. 5: 233. 1903. 



Plate XL fig. 9. 



Forming a rose-colored or reddish brown mass, adhering to rocks or 

 larger algae; filaments entangled, elongate, flexuous, abundantly and re- 

 peatedly branched; false branches spreading, elongate, in pairs, more 

 slender than the primary filament; sheaths colorless, somewhat thick; trich- 

 omes 1.2-2 mic. in diameter, constricted at joints; apical cell rotund; cells 

 shorter than their diameter; cell contents homogeneous, rose-colored. 



Maine. Forming a reddish brown coating on wet cliffs, and especially 

 in "grottoes." Eagle Island, Penobscot Bay. July 1893. (Collins). 



388. Plectonema calothrichoides Gomont. Sur quelques Oscillariees Nou- 



velles. Bull. Soc. Bot. de France. 46: 30. pi. i. f. 6-10. 1899. De 

 Toni. Syll. Algar. 5: 496. 1907. 

 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 13. no. 604. 1899. 



