a single series, empty frond a t length very delicately striate.
Zygospore gloliose, furnished with conical processes.
Size. VO-95 X 10-12 p ; zygospore 20 p.
Archer Micr. Journ. (1873), xiii., p. 100. Lundell Desm.
Suec. (1871), p. 81. Wille Nov. Sem. (1879), p. 60.
Ire lan d ; Sweden, Nova Zemhla.
Flaie X I I I . , fig. 6. a, living cells; b, empty cells; c, zygospores.
C lo s te r ium la g o e n s e . Nordst. Videns. Meddl. Kjob. (18G9),y). 203.
t. 2, / . 2.
Lanceolate, six to seven times longer than broad, somewhat
semi-lnnar, not inflated at the centre, a little spreading at the
extremities, with the apices a very little dilated, rather obtuse,
suddenly attenuated, three transverse stri® in the middle, membrane
becoming brownish, longitudinally striate, with about 16
stri®. Vesicles about 5 in each segment disposed in a central
series.
Siz e . Long 138-166 /x ; broad, 25-28 /x.
Archer Micr. Jonrn. (1873), xiii., p. 213.
Ireland ; Brazil.
Flate X I I ., fig. 5. a, living cell ; b, empty cell.
t f Fronds sliglitly curved, not lunate.
C lo s te x ium c o s ta tum . Corda. Aim. Carls. (1835), t. 5, / . 61.
Frond stout, about flve or six times as long as broad, lunate,
attenuated; upper margin convex, lower concave, ends obtuse,
rounded ; large granules in a single series; empty frond
reddish; stri® few (about six), conspicuous ; suture evident.
Zygospore globose or ovoid-globose, smootli.
Siz e . 0S2 mm. X 65 p (R.) ; diam. 63-70 p (W .) ; zygospore
100-120 p (L.).
Ralfs. Desm. (1848), p. 170, t. 29, f. 1. Archer in Prit.
Inf. (1861), p. 748. Cleve Sver. Desm. (1864), p. 494. Lundell
Desm. Suec. (1871), p. 78. Nordstedt Norges Desm.
(1873), p. 40. Brebisson Liste Desm. (1856), p. 148.
Notaris Desm. Ital. (1867), p. 62, t, 7, f. 66. Rabh. Alg. Eur.
(1868), p. 126. Jacobsen Desm. Deum. (1874), p. 174.
Wolle Desm. U.S., p. 42, t. 6, f. 19. Kirch. Schles. 189.
Closterium doliolatum, Breb. Meneg. Syn. Desm. (1840), p.
287.C
losterium turgidulum, Kutz. Phyc. Germ. (1845), 132.
Closterium dilatatum, Kutz. Phy. Germ. (1845), p. 132.
Closterium striolatium b. costatumJKlehs. Desm. Pruss. (1879),
p. 14.
H ab. I n m a rsh pools and bogs.
Sussex, Surrey, Hants, Gloster, Westmoreland, Cornwall,
Wales, Scotland; France, Germany, Sweden, Italy, Norway,
Denmark, United States.
Flate X .,fig . 3. a, living cell; b, empty cell.
C lo s tex ium stx io la .tum . Ehr. Abh, Berl. ATcad. (1833), p. 68.
Frond from six to ten times as long as broad, lunate,
attenuated; upper margin convex slightly depressed in the
centre, lower concave, ends very obtuse, rounded ; large granules
in a single series ; empty frond reddish, especially near the ends ;
stri® very numerous, crowded, transverse sutures usually three.
Zygospore orbicular, smooth.
Siz e . 0‘3-0'37 mm. x 40-45 p (R.). Diam. 38-40 p (W.).
Ehr. Infus. (1838), t. 6, f. 12. Hassall Fr. Alg., p. 373.
Archer in Prit. Inf. (1861), p. 749, t. 2, f. 2 and 6. Wolle
Desm. U.S. (1834), p. 42, t. 6, f. 8, 20. Ralfs. Desm. (1848),
p. 171, t. 29, f. 2. Cleve Sver. Desm. (1864), p. 494. Lundell
Desm. Suec. (1871), p. 77. Nordstedt Norges Desm. (1873),
39. Nordstedt Desm. Arct. (1875), p. 37, 89. Petit Liste
Desm. Paris (1877), p. 28. Wood P. Water Alg® U.S.,
(1872), p. 109. Wittrock Scan. Desm. (1869), p. 23. Brebisson
Liste Desm. (1856), p. 153. Notaris Desm. Ital. (1867),
p. 62, t. 7, f. 67. Rabh. Alg. Eur. (1868), p. 125 (exol. var.
b.). Wille Nov. Sem. (1879), p. 61. Nordstedt. Desm.
Spitz. (1872), p. 25. Kiroh. Schles. 189.
Closterium striolatum, var. a. vulgaris,^ Jacobsen Desm. Denm.
Closterium striolatum a. typicum, Klebs. Desm. Pruss. (1879),
p. 14.
H ab. In shallow pools.
Widely distributed in England, Wales, Scotland, Ireland;
France, Germany, Italy, Sweden, Norway, Nova Zembla,
Russian Lapland, United States.
Flate X I ., fig. 1. a, living cell; b c, empty cells ; d, zygospore,
C lo s tex ium in te xm e d ium . Ralfs. Lesm. (1848), p. 171, t. 29, / . 3.
Frond slender, twelve to fifteen times as long as broad,
slightly curved, very gently tapering, upper margin convex,
gradually arched, lower slightly concave ; ends obtuse, rounded;
large granules in a single series ; empty frond pale straw-
coloured, stri* distinct, numerous, but not crowded ; transverse
sutures usually more than three. Zygospore globose, smooth.
Siz e . 0-32-0-45 mm. x 2 2 p (R.) ; zygospore 54 p (L.).