Myxophyceae 239 



single or in pairs, long and flexuous, more slender than the primary fila- 

 ment, sometimes branched; sheaths thick and usually colorless; cells of the 

 branches variable, 4-6.5 mic. in diameter, similar to those in the primary 

 filament, often indistinct; heterocysts up to 6 mic. in diameter, 7-21 mic. 

 in length, rectangular, oblong, intercalary; gonidia not known; cell con- 

 tents finely granular, pale blue-green. 



West Indies. Bay Estate, Barbados. (Howard). 



441. Hapalosiphon fontinalis (Agardh) Bornet. Les Nostocacees Hetero- 

 cystees du Systema Algarum de C. A. Agardh (1824) et leur Syno- 

 nymic actuelle (1889). Bull. Soc. Bot. de France. 36: 13. 1889. Bornet 

 and Flahault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 5: 61. 

 1887. (H. pumilus Kirchn.). De Toni. Syll. Algar. 5: 568. 1907. 



Nordstedt. De Algis Aquae Dulcis et de Characeis ex Insulis Sand- 

 vicensibus a Sv. Berggren 1875 reportatis. 7. 1878. (H. braunii Naeg.). 

 WoUe. Fresh-Water Algae. V. Bull. Torr. Bot. Club. 8: 39. 1881. (H. 

 brebissonii Kg.) ; Fresh-Water Algae U. S. 275, 277. pi. 196, f. 2-4, 22, 

 23. 1887. (H. braunii Kg., H. fucescens Kg.). Harvey. The Fresh- 

 Water Algae of Maine.— I. Bull. Torr. Bot. Club. 15. 161. 1888. Bennett. 

 Plants of Rhode Island. 114. 1888. Wolle and Martindale. Algae. Brit- 

 ton's Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 606. 1889. 

 Tilden. List of Fresh-Water Algae collected in Minnesota during 1893. 

 Minn. Bot. Studies, i: 30. 1894. Collins. Algae. Flora of the Blue Hills, 

 Middlesex Fells, Stony Brook and Beaver Brook Reservations of the Metro- 

 politan Park Commission, Massachusetts. 128. i8g6; The Algae of Jamaica. 

 Proc. Am. Acad. Arts Sci. 37: 241. 1901. Saunders. The Algae. Harri- 

 man Alaska Expedition. Proc. Wash. Acad. Sci. 3: 399. 1901. Setchell 

 and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 

 196. 1903. Lemmermann. Algenfl. Sandwich.-Inseln. Bot. Jahrb. 34: 625. 

 1905. Tilden. American Algae. Cent. VII. Fasc. i. no. 627. 1909. 



Plate XIV. fig. 13. 



Plant mass floccose, caespitose, dull blue-green, 3 mm. in height; pri- 

 mary filaments 21-24 mic. in diameter, creeping, interwoven, densely 

 branched on the upper side, containing a single row of cells, rarely two 

 or three, somewhat equal in diameter; sheaths somewhat thick, septate; 

 secondary filaments 9-12 mic. in diameter, long, simple; sheaths continuous; 

 trichomes consisting of a row of single, cylindrical cells; heterocysts inter- 

 calary; hortnogones 6 mic. in diameter, 100-300 mic. in length, made up of 

 from 14-S0 cells. 



Alaska. In a freshwater pond near Seldovia, Cook Inlet. (Saunders). 

 Maine. Old well. College Farm, near Orono. (Harvey). Massachusetts. 

 On the under side of N u p h a r leaves. Spot Pond and Shiner Pool, Middle- 

 sex Fells. (Collins). Rhode Island. Spectacle Pond. (Bennett). New 

 Jersey. On submerged plants in ponds. Dennisville, Atsion, Hammonton. 

 (Wolle). Minnesota. Lake Kilpatrick. June 1893. (Tilden). On perpen- 

 dicular rocks in stone quarry. Near campus. University of Minnesota, Min- 

 neapolis. September 1904. (Lippold). West Indies. On rock. "Wag 



