Algæ U.S. (1872), p. 156. Kirclm. Alg. Sohles. (1878), p.
154. Wolle Desm. U.S. (1884), p. 92, t. 21, f. 1-4. Brebisson
Liste Desm. (1856), p. 184. Notnris Desm. Ital. (1867),
p. 47, t. 4, f. 35. Babil. Alg. Enr. (1868), p. 222, Jacobsen
Desm. Denm. (1874), p. 209.
Cosmarmm armatwn, Breb. in Meneg. Syn. Desm. (1840), p.
218.
X a n th id ium fu r c a iim , Ealfs. Ann. Nat. Hist. (1844), xiv., p.
466, t. 12, f. 1. Hassall Fr. W. Alg. (1845),^p. 359.
E u a s tn m armatum, Kutz. Pby. Germ. (1845), p. 137.
H a b . In ponds.
Widely distributed. Kent, Sussex, Hants, Herts, Norfolk,
Westmoreland, Cornwall, Wales, Scotland, Ireland ; France,
Germany, Sweden, Norway, Denmark, Italy, United States.
Plate X L V ., fig. 1. a, living frond; h, empty frond; c, side view ;
d, end view ; e, empty semi-cell ; / , zygospore.
X a n th id ium a cu le a tum . ETir. A lh . Berl. ATcad. (1833), 1.10,/. 23.
Frond in front view broader than long ; constriction deep,
linear ; segments somewhat reniform ; spines subulate, short,
scattered, chiefly marginal, central protuberance cylindrical,
truncate, border minutely dentate. Zygospore large, orbicular,
beset witb spines which are broad at the base, tapering upwards
to tlie blunt and uncinate extremities.
Siz e . Diam., without spines, 63-71 g ; spines 33 g ; zygospore
66-70 g (K.) ; diam. 62-70 g (Wo.).
Ealfs. Desm. (1848), p. 113, t. 19, f. 1. Kirchn. Alg.
Schles. (1878), p. 155. Archer in Prit. Inf. (1861), p. 736.
Hassall Fr. W. Alg. (1845), p. 360. Rabh. Alg. Eur. (1868),
p. 222. Cleve Sver Desm. (1864), p. 491. Lnndell Desm. Sueo.
(1871), p. 75. Nordstedt Norges Desm. (1873), p. 38. W ittrock
Scan. Desm. (1869), p. 19. Breb. Liste Desm. (1856),
p. 134. Wood F. Water Algæ U.S. (1872), p. 156. Wolle
Desm. U.S. (1884), p. 92, t. 23, f. 10-12.
Zygoxanthum aculeatum, Kutz. Sp. Alg. (1849), p. 178.
H a b . In boggy pools.
Hants, Sussex, Kent, Gloucester, Cornwall ; France, Germany,
Sweden, Norway, Italy, United States.
Plate X L V ., fig. 2. a, living frond; I, empty frond; c, side view; d,
end view.
Plate X L I I I . , fig. 10. Zygospore.
X a n th id ium B ie h is s o n ii. Balfs. Lesm. (1848), g. 113, i. 1 9 ./. 2.
Frond in front view broader th an long ; constriction deep,
acute, not linear ; segments snhelliptic, sometimes irreg u la r ;
131
spines subulate, geminate, marginal; central protnheranoe
cylindrical, truncate, border minutely dentate. ’
S ize. W ith o u t spines 65-70 X 60 g.
Rabh. Alg. Enr. (1868), p. 223. Archer in P rit. Inf.
•(1861), p. 736. Nordstedt Norges Desm. (1873), p. 38.
P e tit Liste Desm. Paris (1877), p. 32. Brebisson Liste
Desm. (1856), p. 134.
Binatella aculeata, Breb. Alg. Fal. (1835), p. 58, t. 8.
Gosmarium aculeatum, Meneg. Syn. Desm. (1840), p. 218,
in part.
Xanthidium bisenarium, Ehr. Mikr. Leb. N. & S. Am.
(1843).
Zygoxanthium aculeatum, Kutz. Sp. Alg., p. 178, pro parte.
var. 0. v a z ia n s. Balfs. Lesm. (1848), g. 113.
Segments broader and more irregular, spines somewhat
irregula r and unequal.
H ab. In ponds, &c.
Sussex, Gloucester, Cornwall; France, Germany, Norivay,
Italy.
Blate X L V ., fig. 3. a, living frond ; I, empty frond; c, end view.
X a n th id ium fa s c icu la tum . Ehr. Infus. (1838), t. 1 0 ,/. 24.
Frond about as long as b ro a d ; constriction deep, lin e a r;
segments somewhat reniform, or snb-hexagonal, t-wlce as
broad as lo n g ; spines slender, subulate, geminate, marginal,
in six p a ir s ; central protuberance short, conical, somewhat
truncate. Zygospore orbicular, large, beset with long
tapering hifld spines.
Siz e . Diam., without spines, 55-63 g ; length, 60-77 g
(K.) ; diam. 55-66 g (Wo.) ; length 43-68 g ; diam., 39-72 g
(D.)
Ralfs. Ann. Nat. Hist. (1844), xiv., p. 467, t. 12, f. 3,
a b e d . Ralfs. Desm. (1848), p. 114, t. 20, f . 1; t. 19, f. -4.
Archer in P rit. Inf. (1861), p. 736. Kirchn. Alg. Schles.
(1878), p. 155. Delponte Desm. (1878), t. 13, f. 20-26.
Cleve Sver. Desm. (1864), p. 491. Breb. Liste Desm.
(1856), p. 134. Lnndell Desm. Suec. (1871), p. 75.
Nordstedt Norges Desm. (1873), p. 38. Hass. F. W. Alg.
(1845), p. 359. P e tit Liste Desm. Paris (1877), p. 32.
Wittrock Scan. Desm. (1869), p. 19. Wood F. Wate r Alg®
U S (1872), p. 157. Notaris Desm. Ital. (1867), p. 48, t. 4,
f. 36. Rabb. Alg. Enr. (1868), p. 223. Wolle Desm. U.S.
(1884), p. 93, t. 22, f. 4, 5. Jacobsen Desm. Denm. (1874),
p . 210.
Euastrum fasciculatum, Kutz. Phy. Germ. (1845), p. 137.