32 ZYGOfHYOEJB.
H ab, Sussex, Lancashire, Cornwall, Wales, Scotland; France,
Germany, Italy, Denmark, Sweden, Mexico, United States,
var. /3. Stri® equal.
Closterium lineatum, var./I. Ralfs. Desm. p. 173.
var. y. Stri® very faint except at the centre of the frond.
Closterium lineatum, var. y. Archer in Prit. Inf. (1861), p.
749.
Plate X I I ., fig. 1. a, living c e ll; h, empty cell.
Plate X V ., fig. 5. Abnormal zygospore, single.
Frond gradually curved, suddenly contracted at the end to a
conical point.
C lo s te x ium a t t e n u a tu m , Ehr. In f. (1838), t. 6 , / . 4.
Frond eight to twelve times as long as broad, gently curved,
gradually attenuated, upper margin slightly convex, lower concave
; extremities suddenly contracted into an obtuse conical
p o in t; large granules in a single series; empty frond reddish,
with numerous close stri®, central suture evident.
Siz e . 0'42 mm. x 3 8 y x (R .) ; 0'36-0'5 mm. x 36 yi (D.).
Diam. 34-42 p (W.).
Ralfs. Desm. (1848), p. 169, t. 29, f. 5. Wolle Desm.
U.S. (1884), p. 41, t. 8, f. 5. Archer in Prit. Inf. (1861), p.
749, t. 3, f. 43. Lundell Desm. Sueo. (1871), p. 79. Brebisson
Liste Desm. (1856), p. 158. Eabh. Alg. Eur. (1868),
p. 130. Jacobsen Desm. Denm. (1874), p. 174.
Closterium candianum, Delponte Desm. (1878), p. 114, t, 17,
f. 7-10. (?)
H ab. Kent, Sussex, Surrey, Westmoreland, Cornwall,
Wales; France, Germany, Italy, Sweden, Denmark, United
States.
Plate X IV .,fig . I. a, living cell; i, empty cell.
**# Frond ventricose or narrowly lanceolate, tapering rapidly
into a distinct leak.
C lo s te x ium R a lf s ii , Ereh. in Ralfs. Lesm. (1848), p. 174, t. 3 0 ,/. 2.
Frond stout, six to nine times as long as broad, the upper
margin slightly convex, lower concave, ventricose at the middle,
each extremity tapering into a narrow slender reddish beak,
shorter than the body, slightly curved downwards, ends obtuse ;
large granules conspicuous in a single series ; empty frond
reddish, especially near the ends ; stri® numerous, close and
distinct, central suture accompanied by several transverse
lines.
S iz e. OB mm. X 60 yx (R.) ; diam. 42-47 p (W.).
Rilfs B rit AK® Exs., No. 30. Wollo Desm. U.S.
(1884), p. 46, t. 7, f. 10. Archer in P r it Inf. (1861), p. 749.
Lundell Desm. Snec. (1871), p. 81.
Desm. (1873), p. 42. Brebisson Liste Desm. (1856), p. 155.
Rabh. Alg. Enr. (1868), p. 135.
Closterium rostratum, Ralfs. in Jenner FI. Tunb. (1845),
Closterium Balfsii b. typicum, Klebs. Desm. Prnss. (1879),
p. 18, t. 2 ,f. 6, 6, c.
H ab. In ponds.
Kent, Sussex, Lancashire, Westmoreland, Cornwall, Norfolk,
Wales, S co tlan d ; France, United States.
Plate X IV ., fig. 3. a, living c e ll; I), empty coll.
Plate X V ., fig. 8. a, empty cell.
C lo s tex ium x o s tia tum . Ehr. A lh . Berl. Alcad. (1831), y). 67.
Frond from ten to fifteen times as long as broad, lanceolate,
upper and lower margins nearly equally convex; each extremity
tapering into a narrow setaceous, nearly colourless
beak, nearly equal in length to the body, curved downwards^
ends obtuse, large granules in a single series, empty irond
colourless, or faintly straw-coloured, stri® .numerous, close,
suture solitary, zygospore somewhat cruciform, w ith concave
S iz e . 0'37 m m .x 2 3 p (R.) ; 0'37 mm. x 35 p (A .);
0’4-0’59 mm. X 21-28 p (D.) ; diam. 23-40 p (W.).
Ehr. Infus. (1838), t. 6, f. 10. M e n eg . Sjm ^ 8 4 0 ) p.
233. Archer in P rit. Inf. (I8 6 I), p. 749, t. 3, f. 44.
Desm. (184«), p. 175, t. 30, f. 3. Delponte Desm. (1878), p.
118, t. 17, f. 63-68. Cleve Sver. Desm. (1864), p.
495. Lundell Desm. Sueo. (1871), p. 81. Nordstedt
Norges Desm. (1873), p. 42. Nordstedt Desm. Arct.
(1875), p. 37. P e tit Liste Desm. P a n s (1877), p. 28.
Wolle Desm. U.S. (1884), p. 46, t. 8. f. 1-3. _ Wood P.
Wate r Alg®. U.S. (1872), p. 115. brebisson
(1856), p. 156. Notaris Desm. Ita l. (1867), p. 66, t 8, f. 73.
Rabh. Alg. Eur. (1868), p. 135. Wille Nov. Sem. (1879), p.
60. Klebs. Desm. Pruss. (1879), p. 18.
■ Glosterium acus, Nits, in Kutz. Syn. Diat. (1833), p. 595.
f 81
Closterium caudatum, Corda Aim. Carls. (1835), t. 5, 66.
Stauroceras acus, Kutz. Phy. Germ. (1845), p. 133.
Grunow Desm. Austr. (1858), p. 497.
H ab. In ponds.
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