io8 ZYGNEMATACEAE 



with concave sides, angles with hornUke processes; spores about 28/x 

 on a side. (PI. XVIII, Fig. 17.) 

 Austria, Karnten. 



74. MouGEOTiA ELEGANTULA Wittrock 1 872. Om Gotland och 



Oelands Sot. Alg., p. 40. 



Vegetative cells 3.5-5 M x 50-1 35 /a; chromatophore with 4-8 pyre- 

 noids in a row; conjugating cells geniculate; conjugation scalar iform; 

 sporangium dividing both gametangia; zygospores cruciate-quadrate, 

 1 8-24 /J. X 18-24/', ^^^^^ rounded corners; spore wall hyaline, smooth; 

 aplanospores ellipsoid, 6-9/1 x 20-24/1, otherwise similar to the zygo- 

 spores. (PI. XVIII, Figs. 21-22.) 



United States: Wisconsin; Iowa; Texas eastward to Massachusetts. 



Widely distributed in Europe; China, Yunnan; West Indies. 



At Twin Lakes, Michigan, a specimen was collected in which a zygo- 

 spore had been formed by scalariform conjugation between 2 cells of the 

 same filament, which had been bent into a loop. 



75. MouGEOTiA BooDLEi (W. & G. S. Wcst) ColHns 1912. Tufts 



College Studies. 3 (2), p. 76. 



Vegetative cells 4-5.5 M x 25-225/1; chromatophore .5-8 of the 

 length of the cell, with 4-6 pyrenoids in a single row; reproduction 

 usually by aplanospores, very rarely by zygospores; conjugation scalar- 

 iform; zygospores quadrangular, 15-18/i x 15-23^, corners somewhat 

 rounded; aplanospores ellipsoid, 12-15/1 x 23-25 /i, projecting slightly 

 on the convex side of the slightly curved sporangia; spore wall yellow 

 to brown, punctate. (PI. XVIII, Figs. 23-25.) 



United States: Illinois, Charleston; Oklahoma (Taft Coll.). 



British Isles. 



Very abundant for several years in a lily pond on the campus of the 

 Eastern Illinois State Teachers College at Charleston, Illinois; fruited there 

 both in the spring and autumn months. Among the hundreds of aplano- 

 spores examined perhaps a total of 25-30 zygospores was found. The Okla- 

 homa specimens had spores darker than the Illinois specimens. 



76. MouGEOTiA GRACiLLiMA (Hassall) Wittrock 1872. Bih. Kgl. 



Svensk, Vetensk,. A\ad. Handl. 1, p. 40. 



Vegetative cells 5-7 /t x 55-140/1; conjugation scalariform; sporan- 

 gia dividing both gametangia; zygospores quadrate, with deeply con- 

 cave sides, 20-25/1 X 20-28/1, angles refuse; spore wall minutely ver- 

 rucose; aplanospores spindle-shaped. (PI. XIX, Figs. 1-2,) 



United States: Texas; Michigan; Illinois to New York and Massa- 

 chusetts. 



Europe, generally distributed throughout. 



