Plmcus chloroplastes Prescott 1944, p. 367 

 PL 87, Figs. 15, 16 



Cells broadly pyriform; produced posteriorly to form a straight 

 or very slightly deflected caudus; broadly rounded anteriorly, with 

 a median papilla; periplast longitudinally striated; margin of the 

 cell entire; chloroplasts several parietal bands lying parallel with 

 the long axis of the cell; paramylon bodies 2 large thin rings or 

 slightly twisted bands lying lengthwise in the cell; eye-spot median, 

 in the apical region; cell 20-22(U in diameter, 29-31/t long. 



This form should be compared with P. hispidula (Eichw. ) Lemm. 



Plankter; from an inlet of Trout Lake, Wisconsin. 



Phacus chloroplastes fa. incisa Prescott 1944, p. 386 



PI. 88, Figs. 5-8 



Cells pyriform or napiform in outline, tapering abruptly to a 

 long, straight sharp caudus; periplast longitudinally striated; margin 

 of the cell with 2 sharp notches on either side; cells 25-26^ in diam- 

 eter, 38-40/t long. 



In cedar swamp. Wis. 



Phacus crenulata Prescott 1944, p. 368 

 PI. 88, Fig. 9 



Cells ovoid-pyriform, posteriorly extended to form a gradually 

 tapering, sharp-pointed caudus; anterior end broadly rounded but 

 bilobed, with a convex papilla between the lobes; flagellum as long 

 as the cell or a little longer; margins of the cell distinctly crenulate 

 or undulate; periplast longitudinally striated with undulating lines; 

 paramylon bodies 2 circular discs; cells 14-15/a in diameter, 34-36/a 

 long. 



This species should be compared with P. costata Conrad, which 

 has spiral entire striations rather than longitudinal wavy ones. The 

 anterior end is different in that species also. P. setosa var. crenata 

 Skv. has spiral striations. 



Plankter; in a cedar swamp. Wis. 



Phacus curvicauda Swirenko 1915a, p. 333 

 PI. 87, Fig. 14; PI. 88, Fig. 21 



Cells broadly ovoid to suborbicular in outline, slightly spiral in 

 the posterior part, which is extended into a caudus that curves 

 obliquely to the left ( when viewed from the ventral side ) ; anterior 

 end broadly rounded; periplast longitudinally finely striated (or 



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