var. minor. Delponte Desm. t. (1876), 1, f. 2, 5, 6, 8, 9.
S iz e . 21 x 18 ^ (D.).
Flate I I I . , fig. 1, e, living cells.
Hyalotheca mucosa. (Mert.) Palfs. Desm. bS, t . \ , f . 2 .
Filament scarcely fragile, mucous sheath very broad ; joints
about as broad as long, not constricted, but having at one of the
ends a minute bidentate projection on each margin, the adjoining
end of the next joint being similar, these projections
being produced by an annular grooved rim.
22^^^ E ^ ^ ^
JRabh. Alg. Eur. (1868), iii., 152. Wolle Desm. U.S.,
(1884), t. 1, f. IS. Ehr. Knrze, Nach. (1840). Breb. Liste
Desm. (1856), p. 118. Archer in Pritch. Inf. (1861), 722.
Ralfs. Brit. Algæ No. 23. Lundell Desm. Sueo. (1871), p. 94.
Nordst. Desm. Bras. p. 296. Nordstedt Norges Desm. (1873),
p. 48. Petit Liste Desm. Paris (1877), p. 29. Wood P.
Water Algæ U.S. (1872), p. 124. Wittrock Scan. Desm.
(1869), p. 26. Notaris Desm. Ital. (1867), p. 26, t. 1, f. 2.
Kirchner Alg. Schles. (1878), p. 131.
Conferva mucosa, Mert. Dillw. Conf. (1809), t. B. Harv.
Man. 127.
Gleoprium mucosum, Hass. F r. Alg., p. 346, t. 83, f. 5. Ealfs.
Ann. N. Hist. (1845), xvi., t. 3, f. 6.
Hyalotheca Ralfsii, Kutz. Sp. Alg. (1849), 187.
Mesotoenium armillare, Delponte Desm. (1876), p. 62, t. 1, f.
13-19.
H ab. In shallow pools, and gentle streams.
Herts, Essex, Sussex, Devon, Kent, Wales, Scotland; France,
Norway, Germany, Italy, Sweden, Brazil, United States.
Plate I I I . , fig. 2. a, living cells; i, transverse view ; c d, empty
cells; e f , empty cells further magnified.
Genus. 5. B& K tB U S IN A . Kutz. (1845).
Cells or joints barrel-shaped, surrounded by one or two narrow
median bands, closely united into nodose jointed filaments.
Chlorophyll mass in end view 6-10 radiate. Zygospores round,
smooth.
B am h u s in a B re h is s o n ii. Kutz. Phyc. Germ. 140.
Joints inflated, barrel shaped, longer than broad, without a
thickened border at their junction, angles biorenate, crenatures
rounded, transverse view circular. Zygospore elliptic, formed
within the persistent extensions from the conjugating joints,
which do not previously break up into single joints, but couple,
still united iu the filament in a confused or zigzag manner,
some of the joints remaining unchanged.
S iz e . Diam. 22 p (R.) ; 18-25 p (W.) ; 2 8 x 3 6 (D.).
Lundell Desm. Suec. (1871), 95. Rabh. Alg. Eur. (1868),
iii., 153. De Bary Conj. 76, t. 4, f. 28, 29. Wolle. Desm. U.S.
(1884), t. i., f. 15-24.
Bamhusina Brehissonii, Kutz. Nordstedt Norges Desm.
(1873), p. 49. Petit Liste Desm. Paris (1877), p. 29.
Wood F. Water Alg® U.S. (1872), p. 125. Breb. Liste
Desm. (1856), p. 119. Rabh. Alg. Eur, (1868), iii., p. 153.
Kirchner Alg. Schles. (1878), p. 132.
Gymnozyga bamhusina, Jacobsen Desm. Denm. (1874), p.
213.
Bamhusina Borreri, Delponte Desm. (1876), p. 66, t. 2, f.
1-7. Wittrook Scan. Desm. (1869), p. ,24. Cleve Sveriges
Desm. (1864), p. 496.
Desmidium Borreri, Ralfs. Ann. N. Hist. (1843) xi., t. 8, f. 4.
Hassall Fr. Alg., p. 348, t. 83, f. 9.
Didymoprium Borreri, Ralfs. Desm. (1848), p. 59, t. 3.
Archer Prit. Inf. (1861), p. 723, t. 2, f. 38, 39. Ralfs. Brit.
Alg® Exs. No. 25.
H ab. In quiet waters.
Hants, Sussex, Norfolk, Westmoreland, Lancashire, Wales,
Scotland, Ireland; France, Germany, Italy, Sweden, Denmark,
Norway, United States.
Plate IT ., fig. 1. a h, living cells ; c d, empty cells (fi after DeBary) ;
e, transverse view ; f g, zygospores.
Genus 6. D E SM IB IU M . Agardh. (1824.)
Filaments 3-4 angular or compressed, regularly twisted,
joints bidentate or biorenate at the angles or lateral margins,
and either closely united throughout the whole of their end
margins by a thickened border, or only at the outer portion of
each by mutual projections, and thus producing intervening
central oval foramina,—Archer in Pritch. Infus. 723.
Desmidium cylindricum. Grev. Sc. Crypt. FI., t. 293.
Sheath distinct ; joints broader than long, with a thickened
border at their junction ; angles bidentate; teeth angular.
I
' I
.11