Phacus anacoelus var. undulata fa. major Prescott 1944, p. 366 



PL 89, Fig. 20 

 Cells broadly ovoid; ending posteriorly in a long obliquely directed 

 caudus; margins of cell with a deep crease on either side, forming 

 2 broad bulges; cells much larger than in the typical form, 64/i, in 

 diameter, 1 1 1-1 15fi long. 

 Euplankter. Wis. 



Phacus asymmetrica Prescott 1944, p. 366 

 PI. 88, Fig. 19 



Cell irregularly ovoid-fusiform and slightly spiral in the posterior 

 and anterior portions; extended into a curved, bluntly-pointed cau- 

 dus posteriorly; narrowed anteriorly and with 2 irregular bulges on 

 either side of the apex; periplast finely striated longitudinally; para- 

 mylon bodies 2 thick twisted rings, usually lying transversely in the 

 cell; chloroplasts numerous small ovoid discs; cell 22-25/* in diam- 

 eter, 50-53ju, long. 



This species should be compared with Phacus Raciborski Drez., 

 which is much more slender and more nearly symmetrical. 



In a roadside fosse. Wis. 



Phacus Birgei Prescott 1944, p. 367 

 PI. 87, Fig. 11 



Cell broadly ovoid, produced posteriorly to form a long tapering 

 caudus which is oblique to the longitudinal axis of the cell, broadly 

 rounded anteriorly; flagellum as long as the cell; periplast veiy 

 finely striated; margins of the cell sharply notched with 4 small 

 indentations on either side; paramylon bodies 1 large and numerous 

 small circular plates; chloroplasts many ovoid discs; pigment-spot 

 ( ?); cell 50-60 fx in diameter, 70-80(it long. 



In a small pond near Genoa City, Wisconsin. 



Phacus caudatus Huebner 1886, p. 5 



PI. 87, Fig. 13 



Cells ovoid-pyriform, spirally twisted, produced posteriorly to 



form a straight, sharp caudus; broadly rounded anteriorly; periplast 



longitudinally striated; 1 large, disc-Hke paramylon body; cells 



15-27 fjL in diameter, 30-50ju. long. 



Euplanktonic and tychoplanktonic. Wis. 



Phacus caudatus var. ovalis Drezepolski 1925, p. 266 



PI. 88, Fig. 13 

 Cells elongate-ovoid, with a short, blunt caudus; cells 18.5/x in 

 diameter, 33.3/a long; periplast smooth ( ?) . 

 With the typical form. Wis. 



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