56 ZYGOPHYOE®.
Size. 107-130 x 98-119 g (K-) ; diam. 100-125 g (W.) ;
length 129 g ; diam. 124 g (D.) ; length 122 g ; diam. 114 g
Desm. (1848), p. 73. t. 9,f. 3 Archer in Prit_ Inf.
f lS e i) , p. 726, t. 1, f. 22. Delponte Desm. ( 1 8 7 6 ), p. 87, t. 4,
}. ? -1k’ "Cleve Svek Desm. (1864), pp. 487. L iiu jll Desm
Suec. (1871), p. 14. Wolk Desm. U.b. (1884), p. IU ,
* or, f 3 Brebisson Liste Desm. (l8o6), p. 1/0.
Petit Liste Desm. Paris (1877), p. q/ ' nartlT
(1869) p. 9. Eabh. Alg. Enr. (1868), p. 190, Pf»Ly-
faLbsen Desm. Denm. (1874), p. 188. Kirchner Alg. behles.
^ E uastyum crux-meltiensis, Ehr. Abh. Berl. Ak. (1831), p.
32. Inf., p. 162, t. 12, f. 3.
H ab. In pools.
Cheshire, Westmoreland, Sussex, Norfolk, Wales ; France,
Germany, Sweden, Denmark, Italy, United States.
Plate X X L , fig- 2. «, living frond ; I, empty fronds; c, transverse
view.
tttic ia ste r ia s Am e z ican a . [ F i r ) Palfs. Lesm. (1848), p. xix.
Frond angular elliptic, more or less punctate ; segments
three-lobed ; lateral lobes broad, cnneate, their margins concave,
inciso-serrate ; end lobe broad, cnneate, and exserted,
bipartite at the angles, the subdivisions narrow, and minutely
dentate at the extremities ; end concave.
S iz e . Length 115-153 ; diam. 92-132 (K .) ; diam, 100-
115 a (W.) ; length 122 g ; diam lOOg (K ) .
Raffili Alg. Ruv. (1868), p. 189. Kirch. Alg. Schle .
(1878), p. 161. Wood F. W. Alg® (1872), p. 143. Wolle
Desm U.S. (1884), p. 112, t. 32 f. 2. Amher in Pr.L Inf.
n 726 t ii f. 44. Clove Sver. Desm. (1864), p.
487. Lundell Desm. Suec. (1871), p. 15. Nordstedt Norges
^% u a s \r um \ k r i c a n u m , Ehr. Mior. Leb (1848).
Micra sle ria s m o n a , Ralfs. Desm. (1848), p. 74, t. 10, i. 1.
H ab . In boggy pools. t t a
Sussex, Wales; France, Germany, Sweden, Norway, United
States.
Plate X X X ., fig. I. a c, living fronds ; I, empty frond.
M ic za ste z ia s d en tic u la ta . Breh. Alg. Fal. (1835), t. 8.
Frond orbicular, smooth ; segments five-lobed ; basal and
middle lobes twice dichotomons, ultimate subdivisions trnnoato-
emarginate wiih rounded angles ; end lobe simply thnoe
emarginate. Zygospore orbicular, beset with scattered stout
elongate spines, at first simple and obtuse, afterwards forked or
trifid, their divisions finally again branched and recurved.
S i z e . Length 250 g ; zygospore 80 (U.) ; length 218 m ;
diam. 182 m (R.).
Ralfs. Desm. (1848), p. 70, t. 7, f. 1. Archer in Prit. Inf.
(1861), p. 727, t. 2, f. 22, Sp. Cleve Sver. Desm. (1864), p.
487. Lundell Desm. Suec. (1871), p. 11. Wolle Desm. U.S.
(1884), p. 109, t. 34, f. 4-8. Nordstedt Norges Desm. (1878),
p. 3. Petit Liste Desm. Paris (1877), p. 31. Wood F.
Water Alg® U S. (1872), p. 145, t. 13, f. 6. Wittrock Scan.
Desm. (1869), p. 8. Brebisson Liste Desm. (1856), p. 120.
Notaris Desm. Ital. (1867), p. 81, t. 1, f. 7. Jacobsen Desm.
Denm. (1874), p. 186, partly. Kirchner Alg. Schles. (1878),
p. 162.
Micrasterias furcata, var. h. denticulata, Eabh. Alg. Eur.
(1868), p. 192.
Micrasterias rota, Meneg. Syn. Desm. (1840), p. 215.
Euastrum rota, Ehr. Inf. (1888), t. 12, f. 1 a.
Micrasterias rotata, Ralfs. Ann. N. H. (1844), xiv., t. 6, f. 1.
H ab. In boggy pools.
"Widely distributed in England, Wales, Scotland ; France,
Germany, Sweden, Norway, Denmark, Italy, United States.
Blate X X I I , fig. a, living frond ; h, empty frond ; c, zygospore.
M ic z a s te z ia s c o z n u ta . Bennett Micr. Journ. (1886), VI., f. 1, f . 6.
Frond oval, very large. Two terminal lobes urn-shaped, very
light green, slightly projecting beyond the margin, and quite
distinct for their whole length, reaching down to an oval quite
colourless space in the centre ; ends of terminal lobes colourless,
concave, not dentate or fimbriate. Each quarter with two deep
and three less deep incisions. Margin perfectly colourless,
consisting of six distinct pieces, each with a deep indentation.
S i z e . Length 855 g, ; diam. 305 g (B.).
H a b . In mountain streams.
Lake District.
Blate X X I I I . , fig. a, living frond; h, empty frond (after Bennett).
; (
! <
Jl
M ic z a s te z ia s z o ta ta . (Grev.J P a lfs ..
t. 6 ,/. 1.
». Nat. Nist. (1844), XIV.
Frond orbicular, smooth, segments five-lobed, basal lobes
twice, middle lobes thrice dichotomons, ultimate subdivisions
acutely bidentate ; end lobe very slightly exserted, its angles
very slightly produced, bidentate ; ends emarginate. An inflated
protuberance in transverse view ju st over central isthmus.
S iz e . Length 280 g ; zygospore 108 g (K.) ; diam. 200-
K