Myxophyceae 243 



summit. Couliabon (3,700 feet), Dominica, January, February 1896.- (El- 

 liott). Hawaii. (Berggren). 



In speaking ofTolypothrix byssoidea cylindrica Tilden, 

 Dr. Setchell states that "although the basal stratum and fasciculi of branch- 

 lets are not well developed, yet the branches seem to indicate this species 

 (F. ambigua) rather than the one to which Miss Tilden has referred it." 

 Further investigation is needed to settle this point. 



447. Fischerella thermalis (Schabe) Gomont. Note sur le Scytonema am- 



biguum Kuetz. Morot. Journ. de Bot. 9: 52. 1895. Bornet and Fla- 



hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 66. 1887. De 



Toni. Syll. Algar. 5: 574. 1907. 



Farlow, Anderson and Eaton. Algae Am. Bor. Exsicc. no. 223. 1877. 



(Scytonema thermale Borzi). Farlow. Notes on the Crypto- 



gamic Flora of the White Mountains. Appalachia. 3: 236. 1883. (F i s c h e r a 



thermalis americana Farlow). Collins, Holden and Setchell. 



Phyc. Bor.-Am. Ease. 5. no. 211. 1896. Lemmermann. Algenfl. Sandwich.- 



Inseln. Bot. Jahrb. 34: 625. 1905. (Stigonema thermale (Schabe) 



Borzi). 



Plate XV. fig. 10, II. 



Plant mass .5 m^m. in thickness, cushion-shaped, woolly, expanded, 

 blackish olive or blue-green; primary filaments 10-13 mic. in diameter, 

 creeping, interwoven, constricted at joints, very much branched on the up- 

 per side; cells somewhat spherical, surrounded by a close, colorless or yel- 

 lowish sheath; branches 7-9 mic. in diameter, erect, cylindrical, or some- 

 times inflated and torulose; cells somewhat quadrate, separated; hormo- 

 gones of three to six cells, showing vacuolar cell contents; sheaths close, 

 continuous; heterocysts intercalary and lateral. 



New Hampshire. On stone in damp woods. Shelburne, Lake Willough- 

 by; on granite rocks near Shelburne. (Farlow). Hawaii. In hot water. 

 Crater of Kilauea, Hawaii. (Schauinsland). 



Var. mucosa Lemmermann. 1. c. 626. pi. 8. f. 16-18. 1905. De Toni. 1. c. 



S7S. 



Plate XV. fig. 12. 



Filaments 14-21 mic. in diameter, slightly or not at all constricted at 

 joints, almost regularly dichotomously branched; sheaths wide, transparent, 

 mucous, trichomes constricted at the joints; cells quadrate, cyHndrical or 

 disc-shaped; apical cell hemispherical, with less granular contents; hetero- 

 cysts not known; hormogones consisting of four to six cells, filled with 

 vacuoles, surrounded by a gelatinous sheath; protoplasmic contents (in 

 preserved material) spindle-shaped or spherical, in contact with that of 

 adjoining cells by means of protoplasmic threads passing through the 

 transverse walls. 



Hawaii. In hot water. Kilauea, Hawaii. (Schauinsland). 



