il
(E d o g o n ium c z a s s iu s c u lum . Wittr. Disp. OEdog. p . 132.
Gynandrosporous. Oogonia single, or twin, globose egg-
shaped or nearly globose, opening by a pore above the middle ;
oospores ellipsoid-globose or globose ; membrane very thick,
almost filling the oogonia; androsporangia 2-5 celled; dwarf
males nearly straight, seated on or about the supporting cells ;
spermogonia 1 (?) celled.
S iz e . Cells •027-‘03 mm., 3^ to 5 times as long ; oogonia
•054-’06 X ’06-'075 mm.; oospore •051-'057 x •052-‘063 mm. ;
androsp. cells •026--028 x 'O l-'O lS mm.; sperm, cell •007-‘009
mm.W
ittr. Mon. OEdog. p. 24.
Epping Forest (1882).
We have only found this species once in pools on the Loughton side
of Epping Forest, but the very thick coat of the oospore is remarkably
distinot, combined with other characters, so -as to render its determination
certain.
Plate L X . jig. 5. OEdogonium crassiusculum with oogonium and
dwarf males ; a, androsporangia ; o, mature oospore x 400.
b. Oospores ellipsoid or egg-
OE d o g o n ium B o r is ia n um . {Le Clero.) Wittr. Disp. OEdog. p. 132.
Gynandrosporous (or idio-androsporous?). Oogonia single
or twin, obversely egg-shaped, opening by a pore above the
middle ; oospores obversely egg-shaped, almost filling the
oogonia ; supporting cells swollen ; androsporangia 2 ? celled,
terminal cell (which sometimes is the oogonium) obtuse, dwarf
males a little curved, seated on the supporting cells ; spermogonia
unicellular.
S iz e . Cells '015--021 mm,, 8-5 times as long ; supporting
cells 'OS-’OSS mm., twice as long ; oogonia •045-’05 x •06-‘075
mm.; oospore •04-'044 x • 051-'054 mm.; androsp. c e l l ’017-
•018 X •015--02 mm. ; sperm, cell •Ol x ^021 mm.
W ittr. Mon. OEdog., p. 25. Kirch. Alg. Schles. p. 55.
Proliféra Borisiana, Le Clerc Prolif. 175, t. 28, f. 6.
OEdogonium apopliysatum, Braun, in Kutz. Sp. Alg. p. 366.
Kutz. Tab. Phy. iii., t. 35, f. 5. Rabh. Alg. Eu r. iii., 251.
OEdogonium setigerum, Vaup. la g t. OEdog. 17, t. 1. Archer
in Quart. Journ. Mior. Soi. 1866, p. 69.
See Mr. Archer’s detailed account of this speoies iu the place above
quoted.
OEDOGONIACEÆ.
OEdogonium con ca ten a tum , {Hass.) WiUr. Mon. OEdog. p . 25.
Gynandrosporous. Oogonia 2-6 continuous, or single, egg-
shaped, or quadrangularly ellipsoid, opening by a pore above the
middle ; oospores filling the oogonia, sporoderm delicately
porose; supporting cell swollen; androsporangia 2-4 celled;
terminal cell obtuse, dwarf males curved, seated on th e supporting
cells; spermogonia 2-4 celled.
S iz e .—Cells •025-’04 mm., 3-10 times as lo n g ; supporting
cells •058-^062 mm., 2 ^ times as long ; oogonia •07-^083 x
•09--105 m m.; oospores -065--076-x 087-’095 mm. ; androsp.
cell -027-'028 x ’03--036 mm. ; sperm cell -013--015 x -022-
•025 mm.
Kirch. Alg. Schles. p. 55.
Vesiculifera concatenata, Hassall F . W. Algæ t. 51, f. 6.
OEdogonium apophjsatum, Pringsh. Beitr. p. 71, t. 5, f. 9.
Eabh. Alg. Eur. iii,, 351, in part.
Britain.
Plate LX I.J ig . 1. OEdogonium eoncatenatum, with oogonium and
thickened supporting cell bearing the dwarf males ; a, androsporangia
X 400.
OE d o g o n ium a o ro sp o rum . De Bary. OEdog. p. 60, f. 3, /. 1-12,
Idioandrosporous. Oogonia solitary, terminal, ellipsoid,
opening by a small apical deciduous (or evanescent) operculum ;
oospore manifestly filling the oogonia, membrane longitudinally
costate ; supporting cells often swollen, terminal cell obtuse ;
dwarf males curved, seated on the supporting cells, stem often
bicellular, upper cells of the stem very long ; spermogonia 1-2
celled.
S iz e .—Cells ‘Ol-’O ll mm., 2-7 times as long; supporting
cells -015--018 mm., 2-3 times as long; oogonia -03-’085 x
•045--051 mm. ; sperm, cell -OOG-’OOS x-014--015 mm.
Archer in Quart. Jo u rn . Micr. Sci. 1867, p. 80, 1868, p.
295. W ittr. Mon. OEdog. p. 16. Eabh. Alg. Eur. iii, 351.
Britain, Ireland.
The terminal oogonia are characteristic of this species, which can
scarcely be confounded with any other.
Plate L X I . Jig. 2. OEdogonium aorosporum, with terminal oogonia,
after De Bary x 400.
OEdogonium c ilia tum . {Hass.) Prings. Beitr. 70, t. 5, f. 8.
Gynandrosporous. Oogonia 2-7, continuous or single, egg-
shaped, opening by an operculum, with a broad fissure ; oospores
egg-shaped, nearly filling the oogonia; androsporangia 2-8
celled, terminal cell setiform, dwarf males curved, seated on the
oogonium ; spermogonia unicellular.
2 A
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