ZYGOPHYCEÆ.
S i z e . Diam. 15-25 g (W.) ; diam. 24 g (D.).
Ralfs. Desm. (1848), p. 90, t. 14, f. 8. Archer in Prit. Inf.
(1861), p. 731, t. 3, f. 13. Delponte Desm. (1876), p. 107, t.
vi, f. 9-10. Cleve Sver. Desm. (1864), p. 486. Lundell
Desm. Suee. (1871), p. 22. Nordstedt Norges Desm. (1873),
p. 10. Wolle Desm. U.S. (1884), p. 107, t. 27, f. 23-24.
Petit Liste Desm. Paris (1877), p. 31. Wood. F. Water
Algæ U.S. (1872), p. 141. Wittrock Scan. Desm. (1869),
p. 7. Brebisson Liste Desm. (1856), p. 124. Notaris Desm.
Ital. (1867), p. 37, t. 3, f. 18. Eabh. Alg. Eur. (1868), p.
186. Wille Nova Zembla (1879), p. 32. Nordstedt Desm.
Spitz. (1872), p. 37. Jacobsen Desm. Denm. (1874), p. 192.
Kirchner Alg. Schles. (1878), p. 159.
Heterocarpella hinalis, Turp. Diet. Des. Soi. Nat. (1820).
Cosmarium binale, Meueg. Syn. Desm. (1840), p. 221.
Euastrum lobulatum, Breb. Desm. Norm., p. 124, t. 1, f. 4.
Euastrum dubium, Niig. Einz. Alg. (1849), p. 122, t. 7 D.,
%. 2.
H ab. In pools.
Sussex, Hants, Surrey, Westmoreland, Gloucester, Cornwall,
Wales, Scotland; France, Germany, Sweden, Norway, Denmark,
Nova Zembla, Spitzbergen, Italy, United States.
Plate X X X V ., Jig. 6. a c e , living fronds j h d f , empty fronds.
var. /3. d en tic u la tum . Kirch. Alg. Sohles., p . 159.
Frond rather larger, rough with a few scattered granules ;
margins of segments crenate, acute angles of end portion
slightly horizontally prolonged, its notch small, rounded.
S i z e . Length 12-29 g ; diam. 10-23 g (K.).
Euastmm binale, var. y. Archer in Prit. Inf. (1861), p.
731. Ealfs. Desm. (1848), p. 90, t. 14, f. 8, / . Lundell
Desm. Suec. (1871), p. 22. Wittrock Scan. Desm. (1869),
p. 7.
Plate X X X V ., fig. 7. a, living frond ; h, empty frond,
var. an gu sta tum . Wittrock.
S i z e . Length 25-28 g ; diam. 17-19 g.
One third longer than broad ; segments hexagonal, narrowed
at the apex, sides retuse.
EMai/nm/ioKr«, Nordst. Desm. Spitzb., p. 37, t. 7, f. 24.
Jacobsen Desm. Denm. (1874), p. 192.
Euastrum binale, var. angustatum Wittr. Sotv. Alg. (1872),
p. 50, t. 4, f. 8. Archer Micr. Journ. (1873), xiii, p. 315.
' Cosmarium angustatum, Nordst. Desm. Arct. (1875), p. 20.
Nordst. and Wittr. Desm. Ital. (1876), p. 35. Wille Nov.
Sem. (1879), p. 39.
Spitzbergen, Nova Zembla.
Plate X X X V ., fig. 9. a h, living fronds; e d, empty fronds.
var. in su la ie . W ittr. Sotv. Alg. (1872), p. 49, t. 4, f .7 .
Archer Micr. Journ. (1873), xiii, p. 315.
Euastrum insulare, Wolle. Desm U.S. (1884), p. 104.
Plate XXXV,, fig. 10. a, living frond; h, empty frond; c, side view.
var. e lob a tum . Lund. Lesm. Suec. p. 23, t. 2, f . 7.
Frond minute, trunoately elliptical in outline; semi-cells
three-lobed; terminal lobe truncate, gibbous, slightly concave,
entire, sutural constriction deep. Each semi-cell with a
moderately con.spiouous projection in the centre.
Size. Length 28 g ; diam. 14 g, (B.).
Euastrum LundelUi, Bennett Roy. Mic. Jouru. (1886), p. 1,
t. I, f. 13.
H ab. Amongst Sphagnum.
Loughrigg; Sweden.
Plate X X X V ., fig. 8. a, living frond; h, empty frond ; c, side view.
E uastzum e zo sum . Lund. Lesm. Sueo. t. II., / . 6.
Small, nearly twice as long as broad, deeply constricted, with
a narrow linear sinus; semi-cells somewhat hexagonal, a little
attenuated about the apex, with a short rounded lobule on the
middle of each side; apex subtruncate, slightly emarginate,
upper angles obtuse, lower rounded; end view somewhat
rectangular, with convex sides, and 3-crenulate ends ; side view
quadrate, narrowed a little at the truncate and obscurely tri-
dentate ends. Cell membrane smooth.
S iz e . Length 39 g ; diam. 23 g (L.).
Bennett Roy. Mior. Journ. (1886), p. 1. Wolle Desm. U.S.
(1884), p. 104.
H ab. In rain water and pools.
Lake District (England) ; Sweden.
Plate X X X V ., fig. 12. a, living frond ; b, empty frond ; c, side view ;
d, end view.
E u a stzum v en u s tum . Preb. Liste, p. 124, t. 1, f . 3.
Small, a little longer than broad ; at each end broadly
truncate, outline undulate, semi-cells quadrately reniform, lower
angles rounded, sides tri-undulate, centre with an ocellate
point. Cell membrane smooth.
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