53 ZYGOPHYCEÆ. DESMIDIEÆ. 59
250 g (W.) ; length 255 g ; diam. 243 g (R.) ; length 288 g ;
R ^ i ï D e s ï ’(i848), p. 71 t 8, f 1. .
(1861), p. 727, t. 1, f. 20. Delponte Desm. P- 83, t.
4 f. 1. Cleve Sver. Desm. (1864), p. 486. Lnndell Desm.
Saec (1871), p. 12. Wolle Desm. U.S. (1884), p. 199,1- 34,
f 1-3. Nordstedt Norges Desm. (1873), p. 5. Wittrook
Desm (1869), p. 8. Brebisson Liste Desm. (18o6), p.
g “ ' B oL S s m . (1867), p 80, . 1, t. 6. J * - »
Desm. Denm. (1874), p. 186. Kirchner Alg. Sohles. (1878),
^ 'Î lL s t e r i a s /arcata, Eabh. Alg. Eur. (1868), p. 191, in
'^^k.chinella rotata, Greville in Hook. Br. El. (1880), v., pt. 2,
rota, Ehr. Abh. Berl. Ak. (1831), p. 82. Ehr.
^^^utomià rotata, Harvey Man. Br. Alg. (1841), p. 187,
H ab. l u clear pools and ditches.
Generally distributed in England, Wales, France,
Germany, Sweden, Denmark, Norway, Italy, United States.
Fiate X X lF .,fia - «, K in g frond; 5, empty frond; e, transverse
view ; d, zygospore.
M ic r a s te r ia s T h om a s ia n a . Archer Micr. Jour«. (1862), il., p . 239,
t, 12, f . 1-IU.
Frond orbicular, smooth ; segments five-lobed, furnished at
the base with three stout conspiciioiis, prominent, hollow pio-
iections the middle conical, rounded, the outer tapering, cuived,
ilo gate emarginate, divergent ; lobes closely approximate
teroughout, each bearing two or three superficial, regnlarly-
dispofed apionlate elevations, their spines directed outwards ,
the Tate al lobes dichotomonsly divided, their ultimate subdivi-
ois t or tridentate, or sometimes qnadndeutate, not taper-
ino- • end lobe wholly included, acutely emarginate its angles
acute End view, the body of the segment lanceolate, projec-
t o i s very conspicuous, together presenting a doubly hastate
outline.
t o m i J a c o t..a D«m.
Denm. (1874), p. 187.
H ab. I n pools.
Ireland; Sweden, Norway, D enm a rk .
Plate XXV., fig. 1. «, K in g frond; b, empty frond - ,d ,e ,fi,g , trans-
verse and end.viewa.
M ic za ste z ia s confezta. Lund. Lesm. Suec. p. 14, t. 1, f . 5.
Small, a little longer than broad, broadly elliptic, sinus deep,
very narrow, linear ; semi-cells five-lobed ; lobes crowded, polar
lobe subcnneate, dilated from the narrow base ; sides concave,
margin of the obtuse angles furnished with two or three minute
papillæ ; lateral lobes equal, out in two lobules, with 2-4 minute
papillæ at the margin ; semi-oells oblong, lanceolate in a vertical
view, in side view oblong ; membrane punctate, often
reddish.
S i z e . Long. 84-87 p ; diam. 74-78 p (L.).
Wolle Desm. U.S. (1884), p. 114, t. 53,^f. 12.
Micrasterias crenata, Cleve Bidrag, p. 487.
Micrasterias granúlala, Wood F. W. Alg. U.S. (1872).
H ab. In pools.
Scotland, Sweden, United States.
Plate x x ym ., fig. 2. a, living frond ; b, empty frond.
M ic za ste z ia s ñmbziata. Ralfs. Lesm. (1848), p . 71, t. 8 ,f . 2.
Frond orbicular, smooth ; segments five-lobed, basal lobes
twice, middle lobes generally thrice dichotomons ; ultimate subdivisions
obtusely emarginate, each furnished with two curved
acute spines ; end lobe somewhat exserted, the angles slightly
produced and rounded, and each furnisheii with two or three
minute spines; ends concave.
S i z e . Length 150-250; diam. 125-200 p (K.) ; length 233
p ; diam. 213 p (R-).
Eabh. Alg. Eur. (1868), p. 193. Jacobsen Desm. Denm.
(1874), p. 187. Kirch. Alg. Schles. (1878), p. 162. Wolle
Desm. U.S. (1884), p. 109, t. 36, f. 1-8. Archer in Prit. Inf.
(1861), p. 727. Cleve Sver. Desm. (1864), p. 486. Lundell
Desm. Suec. (1871), p. 13. Wooá P. Water Algæ U.S.
(1872), p. 145.
Euastrum rota, Ehr. Inf. (1838), t. 12,f. d.
H ab. In boggy pools.
North Wales ; Germany, Sweden, Denmark United States.
Pate X X V I., fig. 1. a, living frond ; b c, empty fronds.
«
M ic za ste z ia s radiosa. Ag. Bot. Zeit. (1827).
Frond orbicular, smooth, segments five-lobed, basal lobes twice,
middle lobes generally thrice dichotomons, ultimate subdivisions
inflated, attenuate towards the end, bidentate, end lobe eruar-
ginate, its angles dentate.
S i z e . Length 150 p ; diam. 144 p (D) ; 182 x 182 p (R.).
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