38 ZYGNEMATACEAE 



spores formed in one of the gametangia, compressed-globose to com- 

 pressed-ovoid, 54-5^ M X 54-65/^ X 47-55/^; median spore wall brown, of 

 2 layers, of which the outer is scrobiculate; pits about 2/^ in diameter, 

 the inner finely and irregularly verrucose. (PI. VI, Figs. 6-7.) 

 Africa, Cape Town (E. L. Stephens Coll.). 



67. Zygnema atrocoeruleum W. & G. S. West 1897. l^ur. Roy. 



Micros. Soc. London, p. 476. 



Vegetative cells 14-17M -x 40-70/1. in diameter; conjugation scalar- 

 iform; zygospores in one of the gametangia; receptive gametangia en- 

 larged or inflated; zygospores globose, 2y-i.6{-2()) i^- in diameter; me- 

 dian spore wall dark blue, smooth. 



England. 



68. Zygnema chalybeospermum Hansgirg 1888. Hedwigia. 27, 



P- 253- 



Vegetative cells 24-27 /a x 24-84 ju.; conjugation scalariform or lat- 

 eral; zygospores in one of the gametangia; receptive gametangia cylin- 

 dric or enlarged; zygospores globose to ovoid, 30-33 m x 30-38 /a; median 

 spore wall blue, thick, smooth. (PI. VI, Fig. 8.) 



United States: Illinois, Casey; Michigan (Ackley Coll.). 



Europe; Asia; North Africa. 



69. Zygnema cyaneum Czurda 1932. Susswasserflora Mittcl- 



europa. 9, p. 127, Fig. 132. 



Vegetative cells 30-32 )u. x 45-60 m; conjugation scalariform or lat- 

 eral; zygospores in one of the gametangia; receptive gametangia cylin- 

 dric or slightly enlarged; zygospores globose to cylindric-ovoid, 30-34 /i- 

 X 38-45 /a; median spore wall blue, thick, smooth. (PI. VI, Figs. 9-10.) 



Bohemia; India. 



70. Zygnema collinsianum Transeau 1914. Amer. Jour. Bot. 1, 



p. 289, PI. 25, Figs. 1-3. 



Vegetative cells 18-25 /a x 32-80 /a; conjugation scalariform; zygo- 

 spores mostly in one of the gametangia, sometimes in one filament, 

 sometimes in the other, rarely in conjugating tube, extending into both 

 gametangia; receptive gametangia enlarged on the conjugating side; 

 zygospores globose to ovoid, sometimes slightly compressed and show- 

 ing a distinct equatorial suture, 26-40 ju. x 30-47 m; median spore wall 

 blue at maturity, thick, pitted; pits 4-5 /a in diameter, 1-2 /a apart; aplan- 

 ospores cyHndric-ovoid, 18-24/1 x 40-76/A, scattered among the vege- 

 tative cells, similar in markings to zygospores. (PI. VI, Figs. 11-13.) 



United States: Oklahoma; Illinois; Indiana; Kentucky; Alabama. 



Northern India (Randhawa). 



