Anabaena affinis Lemmermann 1898a, p. 261 

 PI. 115, Figs. 10, 14, 15 



Trichomes straight or flexuous, solitary and free-floating, either 

 planktonic or intermingled with other algae in the littoral flora, 

 inclosed in a thin, wide, mucilaginous sheath (often indistinct); 

 cells spherical to spheroidal with either homogeneous contents or 

 with pseudovacuoles, especially the latter when plants are solitary 

 in the plankton, 5-6-(7);u. in diameter; heterocysts spherical, slightly 

 larger than the vegetative cells, 7.5-10/x in diameter; gonidia usually 

 short-cylindric, sometimes broadly ovate and truncately rounded 

 at the poles, scattered, sohtary, 9.5-12/x, in diameter, 17— 24— (26) /x 

 long. 



Rare to common in euplankton and tychoplankton of several 

 lakes, Mich., Wis. 



Anabaena Augstumalis Schmidle 1899a, p. 174 

 Trichomes twisted and flexuous, free-floating, solitary; cells barrel- 

 shaped or somewhat cylindric, 4-5|a in diameter, 5-6/x long; hetero- 

 cysts cylindrical, slightly greater (dfji) in diameter than the vegeta- 

 tive cells; gonidia narrowly cylindric, 6/x in diameter, 30-50- ( 56 )/x 

 long, adjacent to the heterocysts. 



This species should be compared with A. circinalis, also a plankter. 

 Euplankter. Wis. 



Anabaena Augstumalis var. Marchica Lemmermann 1905, p. 147 



PI. 115, Fig. 11 



Trichomes flexuous (not circinate), planktonic; cells spherical to 

 cylindric with many conspicuous pseudovacuoles, 5-7 /x in diameter, 

 5-9.5/x long; gonidia cylindrical, 9.5-12/x in diameter, 40-70/x long, 

 remote from the heterocysts. 



In the plankton of several hard water lakes. Mich., Wis. 



Anabaena Azollae Strasburger 1884, p. 352 

 PI. 115, Figs. 12, 13 



Trichomes straight or coiled, often in small clusters but more 

 frequently solitary, inhabiting the tissues of Azolla; cells subglobose 

 to ellipsoid, the contents granular, 4-5/i. in diameter, 6-8-(9.5)/x 

 long; heterocysts ovate, 6-9.5/x in diameter, 9-10-(11.5)/x long; 

 gonidia not known. 



The lack of gonidia in these plants makes their identification 

 questionable. It is possible that they are only a sterile condition 

 of a free-living species called by another name. 



In the tissues of Azolla; shallow water and sloughs. Wis. 



[513] 



