] 



83 



i66. Oscillatoria percursa Kuetzing. Phyc. Gen. 189. 1843. De Toni. Syll. 

 Algar. s: 187. 1907. 



Mackenzie. A preliminary list of Algae collected in the neighborhood 

 of Toronto. Proc. of Can. Inst. III. 7: 270. 1890. 



Plant mass thin, green; trichomas i5-S-i8.S mic. in diameter, some- 

 times solitary, straight; apex of trichome usually curved, somewhat taper- 

 ing, obtuse-truncate; cells 4-6 mic. in length; dissepiments evidently gran- 

 ulated; cell contents very finely granular, pale blue-green. 



Canada. High Park, Toronto. (Mackenzie). 



167. Oscillatoria boryana Bory. Diet. Class. d'Hist. Nat. 12: 465. 1827. 



Gomont. Monogr. Oscill. 254. 1893. De Toni. Syll. Algar. 5: 188. 

 1907. 



Tilden. Notes on a collection of Algae from Guatemala. Proc. Biol. 

 Soc. Wash. 21: 153. 1908. 



Plate IV. fig. 37, 38. 



Plant mass dark lead-colored; trichomes 6-8 mic. in diameter, forming a 

 lax and regular spiral through their entire length, or straight and hooked 

 at the apex, flexuous, constricted at joints; apex of trichome more or less 

 pointed, not capitate; apical cell rotund or acute conical; calyptra none; 

 cells 4-6 mic. in length; transverse walls here and there finely granulated; 

 cell contents showing a few protoplasmic granules. 



Central America. Forming a dark velvety mass in a small stream of 

 warm water a little distance from a hot spring on bank of river. Altitude 

 .3,950 feet. Rio Michatoya, near Lake Amatitlan. January 1906. (Kellerman). 



168. Oscillatoria terebriformis Agardh. Aufzahlung, etc. Flora. 10: 634. 



1827. Gomont. Monogr. Oscill. 234. pi. 7. f. 24. 1893. De Toni. 



Syll. Algar. 5: 189. 1907. 

 Collins. Algae. Flora of the Blue Hills, Middlesex Fells, Stony Brook 

 and Beaver Brook Reservations of the Metropolitan Park Commission, 

 Massachusetts. 127. 1896. 



Plate IV. fig. 39- 



Plant mass dark lead-colored; trichomes 4-6.S mic. in diameter, flex- 

 uous, straight below, loosely spiralled and terebriform above, not con- 

 stricted at joints; apex of trichome slightly tapering, rarely hooked; api- 

 cal cell rotund or truncate; calyptra none; cells 2.5-6 mic. in length; trans- 

 verse walls usually granulated. 



Massachusetts. On rocks and trunks of trees. (Collins). 



169. Oscillatoria subtprulosa (Brebisson) Farlow. Marine Algae of New 



England. 33. 1*881. De Toni. Syll. Algar. 5: 191. 1907. 



Hay and Mackay. List of the Marine Algae of the Maritime Provinces 

 of Canada, vvith Notes. Trans. Roy. Soc. Canada. 5: 1887. Collins. 



Marine Algae of Nantucket. 4. 1888. 



Trichomes 3-4 mic. in diameter, slightly constricted at joints; cells 

 nearly quadrate. 



