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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; zygospores
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; zygospores
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
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. cruciatum
elsewhere.
See also Number 86.
66. Zygnema crassiusculum Transeau 1938. Amer. Jour. Bot.
25, p. 524, Fig. 3.
Vegetative cells ft 52-58 x 52-1 44 ft; conjugation scalariform; zygo-