«tí
Euastrum margaritiferum, Focke Phys. Stud, i, p. 42, in
part.
H a b . In pools.
Lake District; France, Germany, Italy, Spitzbergen, Russian
Lapland, Nora Zembla, United States.
Plate X L I ., Jig. 3, a, living frond; h, empty frond; c, end view; d,
side view.
Cosmarium con fu sum . Cooke M S S .
Medium size or small, constriction deep, linear, lower angles
very acute, rectangular ; lateral margins for a time vertical, then
arching round to form very broadly rounded upper angles,
which merge into the subtruncate upper margin; lateral margins
irregularly serratulo-uudulate, the crenatures so formed becoming
somewhat smaller upwards, presently becoming obsolete ; on
upper angle and upper margin nearly smooth ; front surface
granulate, granules faint and scattered; end view fusiform-
elliptic.
S iz e . Length and diam. 48-50 g.
Cosmarium Brebissonii, Jacobsen Copenhagen Journ. Bot._, t.
vii., f. 15 (forma genuina latior et angustior). Archer Micr.
Journ. 1877, xviii., p. 305.
H a b . In bogs.
Ireland ; Denmark.
Plate X L I I ., fig. 9. a, living frond ; I, empty frond.
Cosmazium amaenum. P re i. in Balfs. Lesm. (1848), p. 102, t. 17,
/• 3.
Frond twice as long as broad, sides parallel, ends rounded,
constriction deep, linear ; segments rough with crowded obtuse
panilla-like pearly granules ; side view much compressed, about
thrice as long as broad ; end view elliptic.
S iz e . Diam. 20-25 g (Wo.) ; length 50 P ; diam. 22 g
(C.).
Breb. Liste Desm. (1856), p. 130. Archer in Prit. Inf.
11861) p. 738- Lundell Desm. Suec. (1871), p. 46. Nordstedt
Norges Desm. (1873), p. 22. Petit Liste Desm. Paris (1877),
T, 30. Nordst. Desm. Braz. (1869), p. 209. Grunow Desm.
Austr (1858), p. 501. Wood F. Water Alg® U.S. (1872),
p. 130. Rabh. Alg. Fur. (1868), p. 159. Rabh. Kryp. FI.
Sachs (1863), p. 201. Lemaire Desm. Vosg». (1883), p. 21.
Wolle Desm. U.S. (1884), p. 78, t. 14, f. 5-7. Wittrock Scan.
Desm (1869), p. 14. Notaris Desm. Ital. (1867), p. 44, t. 4,
f 3 0 .’ Jacobsen Desm. Denm. (1874), p. 196. Kirchner Alg.
Schles. (1878), p. 152. Wille Norges Fers. (1880), p. 37.
DESMIDIE®. I l l
H a b . In poo^g.
Westmoreland, Cornwall, Wales ; France, Germany, Sweden,
Norway, Denmark, Italy, Brazil, United States.
Plate X L ., fig. 2. a, living frond; I c, empty fronds; d, side view,
Cosmazium B o e ch il. Wille Norges Fers. (1880), p . 28, t. 1, / , 10.
Medium size, a little longer th an broad, deeply constricted,
with a very narrow linear sinus. Semi-cells
semi-oiroular, truncate a t the apex, flve-crenate, sides with
three crenations, th e median entire, the others with th e
apex slightly emarg in ate; semi-oells granulate about the
margin, in two series, th e exterior of 15, th e interior of 9
granules, in the centre a tumour w ith four granules oruci-
a tely disposed; side view obovate-oiroular, granulate a t the
margin; end view elliptic, w ith a median tumour on each
side with three g ran u le s; apices five-granulate.
S iz e . Length 29 g ; diam. 27 g (W.).
H a b . Mountain pools.
Lake District, Cornwall; Norway.
Plate X L I I . , fig. 4. a, living frond; I, empty frond; c, end
view ; d, side view.
Cosmazium sp h a le z o stich um . Nord. Sy W ittr. Lesm. Ita l. (1876),
p . 28, t. 12,/. 3.
Small, a little longer th a n broad, deeply constricted, witb
a narrow linear sinus ; semi-cells subreniform, or trapezoid,
stra ig h t a t the base, lower angles rectangular, dorsal margin
broadly truncate and naked, granulated, th e granules iu th e
middle of th e semi-cells often arranged in two or three
vertical series, th e re s t irregularly disposed; end view
elliptic, margin delicately granulate, th e granules, 1-3, in
th e middle larg er and more d is tin c t; side view circular,
granulate. Zygospore globose, or subglobose, smooth.
S iz e . Length 15-20 g ; diam. 13-14 g ; zygospore diam.
18-20 g (N. & W.).
H a b . In pools.
N. W a le s ; Italy.
Plate X L I I . , fig. 6. a, living frond ; h h, empty fronds; c, side
view J d, end view.
Cosmazium ccelatum. Balfs. Lesm. (1848), p . 103, t. 17, / . 1.
Frond in front view about as long as broad, sub-orbicular,
constriction deep, lin e a r ; segments semi-orbicular, with six
broad crenatures a t m argin, rough a t margin with scattered
pearly granules, and a t th e centre with granules somewhat