70 ^ Minnesota Algae 



140. Oscillatoria capitata W. West Jun. Some Oscillarioideae from the 



Plankton. Journ. of Bet. n: 337. pi. 400 a. 1899. De Toni. Syll. 

 Algar. s: 162. 1907. 



Plate IV. fig. 13-15- 



Trichomes 9.6-11.9 mic. in diameter, free or forming a delicate fragile 

 mass, at times spirally coiled and twisted, or curved, or even nearly 

 straight, slightly constricted at joints; apex of trichome slightly tapering; 

 cells 4-8.5 mic. in length; apical cell 6.9-9.1 mic. in diameter, 6.7-8.1 mic. 

 in length, at constriction 3.6-8 mic. in diameter; calyptra more or less con- 

 vex and closely appressed; transverse walls not granulated; cell con- 

 tents homogeneous or somewhat granular. 



West Indies. Lat. 23" 44' N.; long. 45° 30' W. (Murray and Blackman). 



Wille considers this species to be a variety of Catagnymene 

 spiralis Lemmermann. 



141. Oscillatoria corallinae Gomont. Essai Class. Nostocacees homo- 



cystees. Morot. Journ. de Hot. 4: 356. 1890; Monogr. Oscill. 238. 



pi. 6. f. 21. 1893. De Toni. Syll. Algar. 5: 162. 1907. 

 Collins. Preliminary lists of New England Plants. — V. Marine Algae. 

 Rhodora. 2: 41. 1900; The Algae of Jamaica. Proc. Am. Acad. Arts Sci. 

 37: 239. 1901; Phycological Notes of the late Isaac Holden. — I. Rhodora. 

 7: 172. 1905. Lemmermann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 

 618. 1905. 



Plate IV. fig. 16. 



Trichomes gregarious, forming a delicate coating on larger algae, 6-10 

 mic. in diameter, very long, flexuous, at times contorted, contracted at 

 joints, curved gradually and for some distance from the end; apex of 

 trichome scarcely tapering; cells 2.7-4 mic. in length; transverse walls not 

 granulated; cell contents granular; apical cell somewhat capitate, with 

 convex, slightly thickened outer wall. 



Connecticut. On Gelidium. Woodmont; on Enteromorpha, 

 below Yellow Mill Bridge, September. (Holden). West Indies. In a 

 pellicle on coral rock. Port Antonio. March 1893. (Humphrey). Among 

 other algae, near Kingston, Duerden. (Collins). Hawaii. Washings from 

 marine algae. Laysan Island. (Schauinsland). 



142. Oscillatoria nigra Vaucher. Hist. Conferves d'eau douce. 192. no. 



3. pi. IS. f. 4. 1803. De Toni. Syll. Algar. 5: 164. 1907. 



Collins. Algae of Middlesex County, Massachusetts. 15. 1888. Ben- 

 net. Plants of Rhode Island. 115. 1888. West. The Freshwater Algae of 

 Maine. 27: 207. 1889. WoUe and Martindale. Algae. Britton's Catalogue 

 of Plants found in New Jersey. Geol. Surv. N. J. 2: 609. 1889. Anderson. 

 List of California Marine Algae, with notes. Zoe. 2: 217. 1891. Buchanan. 

 Notes on the Algae of Iowa. Proc. Iowa Acad. Sci. 14: 14. 1908. 



Plant mass more or less compact, somewhat membranaceous, usually 

 floating, lead-colored or dark olive green, glistening; trichomes 8.5 mic. 

 in diameter, straight or slightly flexuous; apex of trichome tapering, ob- 

 tusely rounded; apical cell usually straight, somewhat beak-like, bearded, 



