Oscillatoria amphibia C. A. Agardh 1827, p. 632 

 PI. 109, Fig. 6 



Trichomes straight or curved and interwoven to form a thin, 

 blue-green plant mass on submerged objects or in moist aerial habi- 

 tats; not tapering toward the apex. Apical cell broadly rounded, 

 smooth, with a convex outer membrane. Cells (1.5)-2-2.8-(4))ii in 

 diameter, 2-4 times their diameter in length ( 4-8)li ) ; not constricted 

 at the cross walls, which have a single large granule on either side, 

 a series of paired granules showing throughout the length of the 

 trichome. 



In shallow water of lakes, ponds, and swamps; on submerged 

 objects. Mich., Wis. 



Oscillatoria anguina (Bory) Gomont 1892a, p. 214 

 PL 108, Fig. 24 



Trichomes entangled and interwoven to form a dark green plant 

 mass on submerged objects, or intermingled among other algae; 

 straight for most of their length but bent and sometimes twisted in 

 the apical region, slightly tapering toward the apex. Apical cell 

 slightly narrowed and capitate, with a thickened outer membrane. 

 Cells 7-8fx in diameter, short, as little as Ve oi their diameter in 

 length; not constricted at the cross walls, which are granular. Swol- 

 len refringent cells common throughout the length of the trichome. 



Forming films on bottom in shallow water. Wis. 



Oscillatoria angusta Koppe 1924, p. 641 

 PI. 109, Fig. 7 



Trichomes loosely entangled to form a thin plant mass, or solitary; 

 not tapering toward the apex; apical cell bluntly rounded, without 

 a calyptra and not capitate; cells (0.8)-1.1-1.3/j, in diameter, (5)- 

 7-8-(10)/i, long, not constricted at the cross walls; contents nearly 

 colorless, without pseudovacuoles or conspicuous granules. 



Entangled and intermingled with other species of Oscillatoria 

 and miscellaneous blue-green algae, forming a slimy layer in shallow 

 water. Wis. 



Oscillatoria angustissima West & West 1897, p. 300 



PI. 109, Fig. 5 



Trichomes much entangled to form a thin, light blue-green plant 



mass, not tapering toward the apices; apical cell bluntly rounded, 



not capitate and without a calyptra; cells 0.6-1.0/a in diameter, li^- 



3 times their diameter in length; not constricted at the cross walls, 



[485] 



