126 
THE BREAKING OF THE SHROPSHIRE MERES. 
Coelosphserium Kutzingianum, Nag. Einz. Alg., p. 54, t. l.c. 
Families spherical. Cells snbglobose, germinate, or quaternate, loosely 
disposed; cell-contents blue-green, delicately granulose. 
Size.—Cells, ’002—-005 mm.; families, -06 mm. and more. 
Rabli. Alg. Ear. ii., 55 ; Quart. Journ. Micr. Sci., 1869, p. 197; Kirch. 
Alg. Schles, 254. 
In ponds, meres, &c. 
Plate IV., fig. 3. (a) A deposit from a drop of water. ( b ) Two individual 
families united ; the thin line shows the boundary of the transparent 
gelatine surrounding the families. Magnified nearly 350 times, 
(c) This and the figure below show different stages of growth; 
magnified as last. 
Anabsena Hassallii, Nord. and Witt. 
Trichomes equal, curved, often circiuate, interwoven in a thin blue-green 
stratum ; joints globose or more or less compressed, delicately 
granular; heterocysts spherical, colourless, intercalated without 
order ; spores oblong, cylindrical, single or in pairs, distinctly curved, 
dark blue-green, densely granulated, l£-2£ times as long as broad. 
Size.—Cells, -008 mm. ; heterocysts, -009—-01 mm. ; spores, -012 x 
•025 mm. 
Spluerozyga Hassallii , Rabh. Alg. Eur. ii., 195. 
Anabcenaflos-aquce, Hass. Alg., 282, t. 75, f. 2.; Harv. Man., p. 186. 
Dolichospermum Thompsoni, Ann. Nat. Hist. (1850), t. 9, fig. 3. 
Anabcena circinalis, Phillips in Grevillea, ix.,p. 4, t. 134, figs. <?,/, g. 
In ditches with Confervce, and floating on lakes. 
See Plate IV., fig. 2. (a) Represents a deposit from the water, natural size ; 
(b) A group of trichomes, with spores and lieterocysts. (c) and ( d) 
Fragments of the trichome; a group of spores held together by 
gelatinous matter, the trichomes having decayed. 
Aphanizomenon flos-aquse, Ralfs. 
Floating, forming a pale or dark blue-green stratum on the surface of 
the water. Trichomes very thin, nearly straight, aggregated in 
membranaceous flakes which readily separate, either distinctly or 
indistinctly articulated, very pale blue or colourless. Joints 
cylindrical, about as long as broad, slightly granular. Spores more 
or less elongated cylindrical, 6-12 times as long as broad, granular. 
Size.—Cells, -003—’004 mm. diam. ; spores, '005 x '03—-04 mm. 
Allman, Quart. Journ. Micr. Sci., 1855, p. 21, t. 3. 
Byssus flos-aquce, Linn. Spec. Plant. (1753), No. 1168. 
Limnochlide flos-aquce, Kutz. Tab. Phyc. i., t. 91, f. 2 (a). 
Aphanizomenon incurvum, Morr. Bull. Brux., 1839; Harv. Man. 145, 
Hass. Alg. 280, t. 76, f. 6. 
Sphcerozyga Jlos-aquce , Rabh. Alg. Eur. ii., 195. 
Plate V., fig. 6. (a) A bundle of trichomes, magnified 70 times, (b) Two 
detached trichomes. (c) A bundle magnified 350 times. ( d) Two 
detached trichomes showing heterocysts at e ; Trichomes, 'dp. broad ; 
lieterocysts, 5—15 x dp. 
June, 1893. 
