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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 enlarged
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 cylindric
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; aplanospores
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).