Mougeotia virescens (Hass.) Borge 1913, p. 43 

 PI. 72, Figs. 1, 2 



Vegetative cells 8-9-(ll)/x in diameter, 30-80- ( 130 )/a long. 

 Zygospores formed in the tube, dividing both gametangia; quadrate 

 with concave margins and rounded angles; wall smooth and color- 

 less; 29-34. 5ju. in diameter. 



Our specimens agree with M. virescens except that the vegetative 

 cells are a little longer than described. 



In a small pond, Sawyer County, Wisconsin. 



Mougeotia viridis ( Kuetz. ) Wittrock 1872, p. 39 

 PI. 71, Figs. 8-10 



Filaments slender, becoming geniculate in conjugation; cells 6-8/^ 

 in diameter, 24-40- ( 80 );u, long; chloroplast a broad plate extending 

 the full length of the cell with 4-6 pyrenoids. Zygospores formed 

 in the tube, dividing both gametangia; quadrate, the sides concave, 

 corners retuse; median spore wall smooth and colorless; 24-32jU 

 in diameter. 



This is the most common species of Mougeotia in our collections. 

 It appears in many shallow water situations and in roadside trickles, 

 seeps from banks, etc. 



Tychoplankter; in several lakes; in swamps. Mich., Wis. 



MOUGEOTIOPSIS Palla 1894, p. 228 

 Filaments slender, composed of short cylindrical cells; 1 axial, 

 plate-like, folded chloroplast without pyrenoids; conjugation scala- 

 riform, the zygospore formed in the tube, protruding into one or 

 both of the gametangia and not cut off from them by a wall; 

 entire contents of the gametangial cells used in the formation of 

 the zygospore; gametangial cells not becoming filled with lamellate 

 pectic substances. 



Mougeotiopsis should be compared with Debarya, from which it 

 may be differentiated in the vegetative condition by the presence of 

 pyrenoids in the latter. In the reproductive phase Mougeotiopsis 

 may be identified by the lack of pectic substances in the old 

 gametangial cells. In our specimens a gelatinous sheath was some- 

 times present about the filaments. 



Mougeotiopsis calospora Palla 1894, p. 228 



PI. 69, Figs. 4-6 



Filaments light green, long and loosely entangled. Cells short- 



cylindric, sometimes quadrate in the vegetative state, becoming 



elongate in conjugation; 12-14ja in diameter, 14-18^ long. Chloro- 



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