DESMIDIEÆ.
Plate X IV ., fig. 3. a, living cell ; i, empty cell ; o, d, e, conjugation
and development of zygospore, after De Bary.
C lo s tex ium s e ta c e um . Ehr. Abh. Perl. Akad. (1833), p . 239.
Frond very slender, twenty to twenty-five times as long
a.s broad, narrow lanceolate, upper and lower margins nearly
equally and b u t sliglitly convex; each extremity tapering
into a very long, slender, setaceous, colourless beak, longer
than th e body, ultimately curved downwards, ends obtuse ;
empty frond colourless, strioe close, faint, central suture
solitary, zygospore cruciform.
S ize. 0'21 mm. x 10 p (R.) ; 0B6-05 mm. x 18-32 p (D.) ;
diam. 10-11 p (W.).
Ehr. Inf. (1838), t. 6, f. 11. Hassall Fr. Alg. (1845), p.
373. Archer in P rit. Inf. (1861), p. 750. Wolle Desm.
U.S. p. 47, t. 8, f. 6-11. Delponte Desm. (1878), p. 106, t.
17, f. 41-44. Lundell Desm. Suec. (1871), p. 81. Nordstedt
Norges Desm. (1873), p. 42. P e tit Liste Desm. Paris
(1877), p. 28. Wood F. Wate r Algæ U.S. (1872), p. 116.
Brebisson Liste Desm. (1856), p. 166. Notaris Desm. Ital.
1867, p. 67, t. 8, f. 74. Rabh. Alg. Eur. (1868), p. 136.
Jacobsen Desm. Denm. (1874), p. 174.
Stauroceras subulatum, Kutz. Phy. Germ. (1845), p. 133.
Grunow Desm. Austr. (1858), p. 497.
.Stauroceras intermedium, Kutz. Sp. Alg. (1849), p. 166.
Glosterium rostratum, Bailey Amer. Joum. (1841), t. 1, f.
36.
Glosterium (Asteròselene) setaceum, Wittrook Scan. Desm.
(1869), p. 24.
Olosterium rostratum c. setaceum, Klebs. Desm. Pruss.
(1879), p. 18.
H ab. In ponds.
Sussex, Gloucester, Wales, Scotland; France, Germany,
Ita ly , United States.
Plate X IV ., fig. 4. a, living coll ; I, empty cell ; o, formation of
zygospore.
C lo s te x ium K u tz in g ii. Breb. Liste (1856), p. 156, t. 2, / . 40.
Similar to G. rostratum, b u t smaller, stra ig h t in the middle,
narrow lanceolate, each extremity tap erin g into a long,
slender, setaceous beak, which is curved a t th e obtuse ends,
and less th an the length of the body.
S ize, Diam. 17 p (W.),
Wolle Desm. U.S., p. 47, t. 8, f. 8. Lnnd. Desm. Snec.
(1871), p. 81.
H ab. In ponds.
France, United States, Sweden.
Plate X V .,fig . 3. a, living c e ll; 5, empty cell.
Frond minute, tapering, curvature very slight, neither
**** inflated nor rostrate.
C lo s tex ium c o x n u . Ehr. Abh. Berl. Akad. (1830), yj. 62
Frond minute, five to eight times as long as broad, slender,
slightly curved, attenuated, ends b lu n t ; endochrome not
reaching to th e extremities ; large granules indistinct, in a
single series ; empty frond colourless, without stri®. Zygospore
quadrate in front view, elliptic in end view.
S ize. 0'17 mm. x 6 | (R.).
Ehr. Inf. (1838), t. 6, f. 6. Archer in P rit. Inf. (1861), p.
750. Ralfs. Desm. (1848), p. 176, t. 30, f. 6. Cleve Sver.
Desm. (1864), p. 496. Lundell Desm. Sueo. (1871), p. 82.
Nordstedt Norges Desm. (1873), p. 42. P e tit Liste Desm.
Paris (1877), p. 28. Brebisson Liste Desm. (1856), p. 154.
Rabh. Alg. Eur. (1868), p. 137. Wille Nov. Sem. (1879),
p. 59.
Olosterium pronum c. cornu, Klebs. Desm. Pruss. (1879), p.
19.
Stauroceras cornu, Grunow Desm. Anstr. (1858), p. 497.
Glosterium tenue, Kutz. Syn. Diat. (1833), p. 695, f. 78.
H ab. In boggy waters.
Sussex, Westmoreland, W a le s ; Prance, Germany, Italy,
Sweden, Nova Zembla.
var. (3. Frond more turgid.
S ize. O i l mm. x 11 (R.).
Britain, France.
Plate X I I . , fig. 4, a, living cell; b, empty cell
C lo s tex ium a c u tum . Breb. in Ralfs. Lesm. (1848), p. 177, t. 30,
/ . 5, t. 3 4 ,/. 5.
Frond small, slender, from six to twenty times as long as
broad, narrow lanceolate, slightly curved, gradually a tten uated,
ends acute, empty frond colourless, without stri®.
Zygospore somewhat quadrate in front view, end view
elliptic.
S ize. 0 1 4 mm. X 10 p (R.) ; O i l mm. X 12 n (N.) ; diam.
9-11 p (W.).
i 1
i '
/
Vi
I f
,1 <
41
'F: