Kirchneriella obesa ( W. West ) Schmidle 1893, p. 16 [83] 



PL 58, Fig. 5 

 Colony composed of many irregularly arranged cells in a wide 

 gelatinous envelope; cells strongly lunate, the outer margin convex 

 and the inner nearly parallel to it, tapering slightly to bluntly 

 pointed apices; chloroplast covering the entire convex portion of 

 the wall; cells 4-6yu, in diameter, 10-14/a long. 



Rare but widely distributed; in the plankton of many lakes. Mich., 

 Wis. 



Kirchneriella obesa var. aperta (Teil.) Brunnthaler 1915, p. 182 



PI. 58, Figs. 6, 7 



A variety in which the cells are less strongly lunate, with the 

 inner margin of the cell describing a much greater arc than the 

 outer; cells 7.4-10;u, in diameter, 10-14/i, long. 



Rare; in the plankton of several lakes. Wis. 



Kirchneriella obesa var. major (Bernard) G. M. Smith 1918, p. 636 



PI. 57, Fig. 12 

 A variety diJBFering from the typical by having the inner and 

 outer margins nearly parallel, slightly tapering at the apices, which 

 are bluntly rounded; cells 3-5/x in diameter, 10-18- ( 21 )/x long. 

 Rare; in plankton, Mich., Wis. 



Kirchneriella subsolitaria G. S. West 1908, p. 284 

 PI. 58, Fig. 8 

 Plant consisting of 4 strongly curved, crescent-shaped cells ar- 

 ranged together within old mother cell wall, the apices bluntly 

 rounded and not tapering; cells 3-4.5jLt in diameter, 10-14/^ long. 

 Euplankter. Wis. 



QUADRIGULA Printz 1915, p. 49 



A free-floating, ellipsoid colony of 2-4-8 long-cylindrical or fusi- 

 form cells with long axis parallel with that of the gelatinous sheath 

 in which they are inclosed; poles of the cells subacute or sharply 

 rounded; chloroplast a parietal plate covering most of the cell wall, 

 or sometimes located along one side; pyrenoid sometimes present. 



Some species of this genus will be found treated under 

 Ankistrodesmus in a number of manuals. The two genera are 

 separable on the basis of their arrangement in the colony and the 

 common investing sheath, the latter not being present in 

 Ankistrodesmus. 



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