ZYGNEMA 37 



Vegetative cells 31-33/^ x 45-95/^; conjugation scalariform; zygo- 

 spores in one of the gametangia; receptive gametangia cylindric or 

 enlarged on the conjugating side; zygospores ovoid to cylindric-ovoid, 

 32-36^1 X 42-60 /x; median spore wall yellow-brown, thick, outwardly 

 shallow pitted (visible only in section), and densely and finely verru- 

 cose. (PL VI, Fig. 3.) 



Czechoslovakia. 



63. Zygnema mirandum Taft 1946. Trans. Amer. Micros. Soc. 



65, p. 24. 



Vegetative cells 28-35 /j- ^ 32-64 ft; conjugation scalariform; zygo- 

 spores formed in one of the gametangia; receptive gametangia greatly 

 enlarged on the conjugating side; zygospores compressed-globose to 

 ovoid; median wall carinate; spore wall thin and smooth; median spore 

 wall yellow-brown, of 2 layers, the outer thick and smooth, the inner 

 reticulate, with the thin ridge crests irregularly broken; innermost 

 spore wall smooth. (PI. VI, Fig. 4.) 



United States: Texas, Austin and Fredericksburg, April 22-24, ^93^- 



64. Zygnema inconspicuum Czurda 1932. Susswasserfiora Mtttel- 



europa. 9, p. 122, Fig. 127. 



Vegetative cells 36-39 /x x 50-70 /a; conjugation scalariform; zygo- 

 spores in one of the gametangia; receptive gametangia cylindric or 

 scarcely enlarged; zygospores ovoid, sometimes extending into the en- 

 larged tube, 40 /x X 50-60 ft; median spore wall brown, pitted; pits 4-5 M 

 in diameter, 4-5 /^ apart. (PL VI, Fig. 5.) 



Finland; Manchuria; northern India. 



See also Number 86. 



65. Zygnema neocruciatum Transeau 1934. Trans. Amer. Micros. 



Soc. 53, p. 212. 



Vegetative cells 40-50 /a x 30-100 /a; conjugation scalariform; zygo- 

 spores in one of the gametangia; receptive gametangia cylindric or 

 slightly enlarged; zygospores globose to cyHndric-ovoid, filling the 

 gametangia, 40-45/11 x 40-50^1; median spore wall brown, scrobiculate; 

 pits about 2ft in diameter, 3-4 ft apart; aplanospores common and sim- 

 ilar in size, rarely to 80 fi in length. 



United States: Illinois. Probably included in many records for Z. cru- 

 ciatum elsewhere. 



See also Number 86. 



66. Zygnema crassiusculum Transeau 1938. Amer. Jour. Bot. 



25, p. 524, Fig. 3. 

 Vegetative cells 52-58 ft x 52-1 44 ft; conjugation scalariform; zygo- 



