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ZYGNEMA 27
55-60 /a; median spore wall brown, scrobicialate; pits about 3/^ in diam-
eter. (PI. Ill, Fig. 8.)
United States: Illinois.
20. Zygnema giganteum Randhawa 1936. Proc. Indian Acad. Sci.
4, p. 241.
Vegetative cells 40-48 /a x 56-90 /a; reproduction by zygospores and
aplanospores; conjugation scalariform; zygospores formed in the con-
jugating tubes; zygospores ovoid to globose, 48-64 /^ x 56-70 /a; median
wall yellow-brown, of 2 layers, of which the outer is undulate pitted and
the inner smooth or granulate. The other 2 walls are transparent.
Aplanospores cylindric, filling the cells, with walls similar to those of
the zygospores, 38-48 /a x ju-. 45-72 (PI. Ill, Figs. 9-10.)
India, Kapurthala State, Punjab, March, 193 1.
This description is modified from the original on the basis of specimens
kindly sent by Mr. Randhawa. Associated with this species in the original
collection is an anisogamous species with very peculiar conjugating tubes, in
that a ring of pectic material surrounds the tube at the point of union. This
is indicated by Randhawa's figures. However, there are no ripe spores in
the material that I have seen and because of the smaller zygospores I believe
it is a distinct and unnamed species.
21. Zygnema gedeanum Czurda 1932. Susswasserfiora Mittel-
europa. 9, p. 115, Fig. 118.
Vegetative cells 13-15 j^a x 32-34 ;u; conjugation lateral; zygospores
formed in the conjugating tubes, ovoid, 22-24 /a ^ 3P~?P-l^''> median spore
wall blue to blue-black, thick, pitted; pits about im in diameter. (PI. Ill,
Figs. 11-12.)
Java.
22. Zygnema cyanosporum Cleve 1868. Nova Acta Reg. Soc. Sci.
Upsali. 6, p. 28, PI. 8, Figs. 6-8.
Vegetative cells about 20-22/1. x 40-180/t; conjugation scalariform;
zygospores formed in the conjugating tubes, globose, rarely quadrate-
globose, 30-40 ju. in diameter; median spore wall blue, thick, smooth.
United States: Michigan.
Greenland; Sweden; Finland; India; South Africa.
23. Zygnema czurdae Randhawa 1936. Proc. Indian Acad. Sci.
4, p. 239.
Vegetative cells 20-27 /a ^ 30-100/1, with 2 chromatophores; conjugation
lateral and scalariform; spores formed in the tubes; during
lateral conjugation the intergametangial wall sphts and the gametangia
are connected only by the enlarged tubes; in scalariform conjugation the