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102 ZYGNEMATACEAE
outer pectic layer, which may be 7-10/i in thickness; spore wall brown,
smooth. (PI. XVI, Fig. 17.)
British Isles; Sweden; Finland; Latvia; Spain.
53. MouGEOTiA DisjuNCTA Tfanscau 1934. Trans. Amer. Micros.
Soc. 53, p. 222, Figs. 50-51.
V^egetative cells 14-18^ x 50-200^; chromatophore with 2-8 pyre-
noids in a line; conjugation scalariform; zygospores in the conjugat-
ing tubes, compressed-globose, 24-32 m x 21-28 m; sporangium wall
changing during maturity to pectic substance and becoming as much
as 25 iu, in thickness and pushing the 2 gametangia apart, but supporting
the zygospore within; spore wall chestnut brown, punctate, suture
prominent. (PI. XVII, Figs. 7-8.)
United States: Florida, Fort Myers (Tiffany Coll.); China, Hunan
(lao 1940) listed as A/, gelatinosa.
54. MouGEOTiA oEDOGONioiDES Czufda 1931. Bcih. Bot. Zentralbl.
48, p. 286.
Vegetative cells 16-18 /a in diameter, with 1-2 platelike chromatophores,
each with 2-3 pyrenoids; conjugation scalariform between
geniculate cells, lateral by the solution of the cross wall and the development
of a conjugating tube between the ends of the gametangia;
subsequently, in both cases, following the union of the gametes, the
sporangium wall changes to a thick pectic layer, 8-20 a*^ in width; the
gametangial wall at the point of union with the sporangium becomes
modified, suggesting the ring scars of Oedogonium cells; zygospores
globose or compressed-globose, 41-50/^1 x 40-41
/a; outer wall thick, color-
less, smooth; spore wall yellow, thick, and irregularly corrugate, with
a distinct equatorial suture. (PI. XVII, Figs. 9-10.)
Asia, Tibet.
55. MouGEOTiA CYANEA Transcau 1926. Ohio Jour. Set. 26, p. 321.
Vegetative cells (i4-)i6-i8(-2o))u. x 160-200 ;ia; chromatophore
occupying one-third to one-half of the cell, with 4-10 pyrenoids in a
row; conjugation scalariform; zygospores in the conjugating tubes,
compressed-spherical, 38-48^11 x 30-40 /a, with the long axis parallel to
the filaments; spore wall blue, finely punctate; aplanospores spheroidal,
laterally placed in the sporogenous cell, 30-32)", in diameter; both kinds
of spores surrounded at maturity with a transparent pectic layer, 4-8 /i
thick, which may disappear in preserved specimens. (PI. XVII, Figs.
15-17-)
United States: Michigan and Ohio to Texas and Florida.