Scenedesmus armatus (Chod.) G. M. Smith 1916a, p. 460 



PL 62, Figs. 13, 14 



Plant composed of 2-8 cells arranged in a single, partially alter- 

 nating series, oblong-ellipsoid but with ends broadly rounded; 

 terminal cells with a single, long, usually curved or unevenly bent 

 spine at each pole; central cells with a median, incomplete longi- 

 tudinal ridge; cells 6-8^ in diameter, 9-15ju, long. 



Widely distributed and fairly common in a variety of lakes and 

 ponds. Mich., Wis. 



Scenedesmus armatus var. Chodatii G. M. Smith 1916a, p. 461 



A variety with more slender cells and with proportionately less 

 of the lateral walls in contact so that the notches between the poles 

 of adjacent cells are deeper; cells 4-5ix in diameter, 11-15/a long. 



Wis. 



Scenedesmus armatus var. major G. M. Smith 1920, p. 155 

 PI. 62, Fig. 15; PI. 63, Fig. 23 

 Cells larger than in the typical plant, 9/* in diameter, 25/x long; 

 spines longer, 15ja. 

 Wis. 



Scenedesmus armatus var. subalternans G. M. Smith 1916a, p. 461 



Colony composed of pyriform cells, subalternately arranged in 

 two series; cells 3-5.5ju, in diameter, 9-12/x long. 



Wis. 



Scenedesmus Bernardii G. M. Smith 1916a, p. 436 

 PI. 63, Fig. 1 



Colony composed of 2-8 fusiform, lunate, or sigmoid cells in a 

 single series, but with terminal cells at an angle to the plane of 

 arrangement of the inner cells; cells adjoined alternately by the 

 apex of one cell to the midregion of the next in series; wall without 

 spines or teeth; cells 3-6/x in diameter, S-llfx long. 



Mich., Wis. 



Scenedesmus bijuga (Turp.) Lagerheim 1893, p. 158 

 PI. 63, Figs. 2, 7 

 Colony composed of 2-8 cells in a single (rarely alternate) flat 

 series; cells ovate or oblong, without teeth or spines; cells 4-8/x in 

 diameter, 8-1 6/i long. 



Widely distributed; often appearing as a prominent component 

 of the littoral plankton. Mich., Wis. 



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