I
There seema to be no specific difference between the two species of
ii. Hassall, the only feature relied upon bein<r
that the filaments m the latter are scarcely more than half the diameter
Ot the rormer.
Flate XLI. fig. 4. sterile cells X 400 ; b, fertile cells, with
zygospores, X 400. I \g . 5, var. ovalis. a, sterile cells X 400 ; b, fertile
cells, with zygospores, X 400.
t t Spore membrane smooth.
M e so c a ip u s p a r v u lu s . (Hass) B e Bary.
Sterile cells 5-12 times as long as broad. Zygospore spherical;
membrane even, commonly twice the diameter of the
threads.
S iz e . Cells '01 mm. Zygospore •02--024 mm
De Bary Conj. p. 80, t. 2, f. 15. Cleve Mon. Zyg. p. 31 t
^ k - 1 6 9 , t. 45, f. 2, 3. Jenner FI. Tunb!
Wells 184.
f parvulus, Hass, Ann. Nat. Hist. xi. 434, t. 7,
Mougeotia splendens, Kutz. Tab. Phy. v. p. 1.
var B . a n g u s tu s . Hass.
Mesocarpusparvulus, Ystv. tenuissima,10-14. B s BarY GoaJ\ - t • 1 1 ) f•
Mesocarpus angustus, Hass. Alg. 170, t. 45, f. 4,
^ Sphoerocarpus angustus, Hass. Ann. Nat. Hist. xii. 187, t. 7,
Mixed with other Algæ, in ponds, &c.
Plate XLII fig. 3. a, sterile cells X 400; b. e, fertile cells, with zygo-
epores, X 400. Mg. 4, var. angustus. a, sterile cells X 400 ; b, fertile
cells, with zygospores, X 400 ; c, mature zygospore X 400.
M e s o c a ip u s s o a la iis . (Hass.) DeBary.
Sterile cells 2-4 times as long as broad ; zygospore spherical
or broadly ovoid; membrane brown, even, about equal in
diameter to the threads.
Siz e . CeUs -OSd mm. diam. Zygospore -034 mm. diam,
De Bary Conj. p. 80. Cleve Mon. Zyg. p. 32 t. 9 f,
11, 12. Hass. Alg. 166, t. 42, f. 1. Hass. Ann. Nat. Hi.st! x
p. 4 o ; xii. t. 7, f. 7. Rabh. Alg. Eur. iii. 257. Kutz. Tab
Phy. V. t. 5.
m socarpus i n i r ^ Hass. Alg. 1 67, t. 48, f. 1. Jenner
Jrl. lu n b . Wells 184.
Sphoerocarpus intricatus, Hass. Ann. Nat. Hist, xii, 186 t.
7, f. 9. '
ZYGNEMAOBÆ. 105
We can recognize no plausible grounds on which the M. intricatus of
Hassall can be maintained as a species distinct from M. '
Plate XLII. fig. 1. a , sterile cells X 4 0 0 ; b, conjugating cells, with
zygospores x 400.
M e so ca ip u s le c u z v u s . Hass.
Sterile cells 5 to 10 times as long as broad.
Zygospore globose. Sporoderm brown, even.
S iz e . -0 12 - '0 18 mm. Zygospore ‘023 mm. diam.
Hass. A lg . 16 8 , t. 44, f. 1 . Eabh. A lg . Enr. iii. 257.
Sphairicarpus recurvus, Hass. Ann. N. Hist. xii. 186, t. 7 ,f. 10.
In ditches.
Plate X L I I . fig . 2. a, sterile cells X400; b, conjugating cells with
zygospores X 400.
Sub-Genus P le u r o o a u p d s . Braun.
Mesocarpus p leu zo ca ip u s. De Bary Conj.p. 81.
Sterile cells 2 to 3 times as long as broad.
Zygospores subglobose, brown, even.
S iz e . Cells •025--03 mm. Zygospore -03 mm. diam.
Pleurocarpus mirabilis, Braun. A lg . Uni. p. 60. Rabh A lg
iii, 258.
Zygogonium pleurospermum, Kutz Tab. v. t 1 3 .
Mougeotia genuflexa, A g . and others. Eng. E l. v. 360. Eng.
Bot. Ed. 1 1 . t. 2505. Jenner. F L Tunb. Wells, 18 2 . Hass.
A lg . 17 2 , t. 40, f. 2. Harv. Man. 1 4 1 . Mack. FI. Hib. 2 3 1 .
Dickie Bot. Guide, 296.
Conferva genuflexa, Dillw. Conf. t. 6. Eng. Bot. Ed, 1 , t.
19 14 .
Zygnema genuflexum, Johnst. F L Berw. ii. 2 5 7 . Grev. FI.
Ed. 320.
Serpentaria genuflexa. G ray A rr. 1 , 300.
var. compressus.
Mougeotia compressa, Eng, F L v. p. 860. En g , Bot. Ed. 2
p. 17 2 . Harv. Man. 1 4 1 .
Zygnema compressum, Lyngb. Hyd. Dan. t. 58.
Serpentaria compressa. Gray A r r . 1 . 300.
Pleurocarpus compressus, Rabh. A lg . Eur. iii. 258.
In moor pools, &c.
This widely diffused species forms vast yellowish.green masses, which
Harvey says are often thirty feet in diameter ; we have often met with
them covering several square feet. The filaments are fragile, soon
breaking into short lengths, bent almost at right angles and united at the
angles, hence the old name of Mougeotia genufiexa.
Plate X L I I I . fig . I. Cells in conjugation X 400; b, fertile cells
with zygospore, after De Bary X 400; c, c, zygospores X 400.
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