Myxophyceae 237 



C2) Trichomes consisting of one to several rows of cells 

 A Branches unilateral, thin, finally forming hormogones 



Fischerella 

 B Branches scattered; hormogones formed in the apices of the 

 branches or in special short branches Stigonema 



2 Filaments growing together forming a cushion-like mass 



Capsosira 



II Sheaths confluent into a gelatinous amorphous mass 



Nostochopsis 



Genus MASTIGOCOLEUS Lagerheim. Notarisia. i: 65. 1886. 



Filaments free, irregularly branched; branches of two kinds, the one 

 cylindrical, the other flagelliform, tapering off into a hair-like apex; sheaths 

 continuous; trichomes, except in the branches, single within the sheath; 

 heterocysts single, rarely in pairs, terminal or lateral, sometimes intercal- 

 ary; gonidia unknown; reproduction by means of hormogones; cell con- 

 tents homogeneous. 



438. Mastigocoleus testarum Lagerheim. Note sur le Mastigocoleus, Nou- 

 veau Genre des Algues Marines de I'Ordre des Phycochromacees. 

 Notarisia. i: 65. pl. i. 1886. Hornet and Flahault. Revis. des Nos- 

 toc. Ann. Sci. Nat. Hot. VII. 5: 54- 1887. 'De Toni. Syll. Algar. 5: 

 564. 1907. 

 Collins. Algae. Rand and Redfield's Flora of Mount Desert Island, 

 Maine. 247. 1894. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. S- 

 no. 213. 1896. Setchell. Notes on Cyanophyceae. — III. Erythea. 7: 47. 

 1899. Collins. Preliminary Lists of New England Plants. — V. Marine 

 Algae. Rhodora. 2: 42. 1900; The Algae of Jamaica. Proc. Am. Acad. Arts 

 Sci. 37: 241. 1901; Phycological Notes of the late Isaac Holden. — II. Rho- 

 dora. 7: 223. 1905. 



Plate XIV. fig. 12. 



Filaments 6-10 mic. in diameter, variously curved; sheaths thin, color- 

 less; trichomes 3.5-6 mic. in diameter; cells cylindrical or nearly so; hetero- 

 cysts exceeding the diameter of the trichome, 6-18 mic. wide and long; 

 cell contents greenish. 



Canada. In oyster shells. Malpeque, Prince Edward Island. (Faull). 

 Maine. Growing in the substance of dead shells. Seal Harbor. (Collins). 

 Massachusetts. In shells ofMya arenariaona sandy beach below low 

 water mark. Quisset. July 1893, 1895. (Setchell). Rhode Island. (Collins). 

 Connecticut. In shells. Fresh Pond. August, September. (Holden). Cal- 

 ifornia. In shells of the Eastern oyster. Near Bay Farm Island, Alameda 

 County. (Setchell). West Indies. In old shells. Kingston, Jamaica. 1897. 

 (Humphrey). Jamaica. (Flahault). 



Genus HAPALOSIPHON Naegeli in Kuetzing. 

 Spec. Algar. 894. 1849. 



Plant mass caespitose-floccose, thin, aquatic; filaments free, not grow- 



