i l
if
1
Siz e . Cells •003--004 mm., heterocysts rather longer.
Spores -014 x •025-'03 mm.
Kiroh. Alg. Schl. 237. Eabh. Alg. Eur. ii., 186.
Anabaina impalpebralis, Hass. Alg. 283, t. 75, f. 3.
In ditches and ponds.
Plate X C V . fig. 1. Trichomes with heterooysts and spores X 400.
Cylindzospeimum ca ten a tum . R a lfs A nn. Nat. Hist. t. 8 ,/ . 14.
Stratum bluish green. Trichomes very fine elongated
straight, or slightly flexuous, generally parallel, moniliform.
Joints sphærical minute. Heterocysts oval.- Spores 2-8 in
each series, at first spbærical, then more or less oval, but little
broader than the heterocysts.
S iz e . Cells about -003 mm., heterocysts a little longer,
spores a b o u t-006 x -00 8 mm.
Kabh. Alg. Exs. No. 1858.
In fresh water.
Clearly distinguished from the preceding speoies by its numerous
spores.
Plate X C V . f g . 2. Trichomes with heterooysts and spores X 400.
Genus 99. NODULARIA. Mertens. (1822.)
Triobomes distinctly vaginate, with very closely compressed
disc-shaped joints, collected in a gelatinous or membranaceous
irregularly diffused stratum. Heterooysts intercalated at regular
intervals, vegetative joints nearly equal, transversely
compressed. Spores fuscous, or golden yellow, becoming tawny,
globose, slightly compressed.
N od u la iia lito r ea . (Thw.) Thur. Ann. Sci. N a t 1875, 378.
Scarcely gelatinous, forming a deep green fleecy covering to
floating plants on which it occurs. Trichomes of considerable
diameter, nearly straight. Joints of a beautiful blue green
colour, very short and compressed, giving the filaments the appearance
of an Oscillaria. Heterocysts pale reddish. Spores
elliptical, at length acquiring a deep brown colour.
S iz e . Triohome, without sheath, -012 mm.
Born, and Thur. Notes Algol, ii., 121, t. 29, f. 1-9.
Spermosira litorea, Kutz. Phy. Gen. 213. Kabh. Alg. Eur.
ii., 186. Harv. Phy. Britt, t. 113, f. c.
Plate XOV. fig. 3. a, portion of trichome, with heterocysts X 400;
b, portion X 600; c, fertile portion, with spores X 600; d, spores X 600;
e, spore germinating, after Thuret.
N o d u la iia H a iv e y a n a . Thur. in A nn. Sci. N a t 1875, 378.
Trichomes much curved, composed of cells nearly as long as
broad. Heterocysts subquadrate, rather longer tban wide, and
of tbe same width as tbe joints. Spores sphærical, almost
twice the diameter of the joints.
S iz e . Triobomes -0065 mm. diam.
Born, and Thur. Notes Alg. ii., t. 29, f. 14-16.
Spermosira Harveyana, Tbw. in Harv. Phyc. Britt, t. 173,
f. c. Eabh. Alg. Eur. ii., 295.
In brackish ditches.
Plate XOV. f g . 4. a, portion of trichome with heterooysts x 400 ; b,
the same X 600 ; e, portion of triohome with spores X 600 ; d, germinating
spores, after Thnret.
F a m il y I I . LYNGB
Filaments without heterooysts, and destitute of a terminal
hyaline hair, single, and scattered, or numbers associated in
bundles and enclosed in a common sheath, often radiating.
Joints shortly cylindrical, disc-shaped in section.
Genus 100. S F IR V L IN A . Link. (1834.)
Trichomes articulated, spirally twisted, motile, nestling in a
more or less liquid colourless matrical mucilage. Propagation
unknown.
Consult Cohn in Nova Acta Car. Leop. vol. xxiii. Braun in Botanisohe
Zeitung 1862, p. 395. Eeinicke Beitr. zur neuern Mikrosk ii., pp.
1-56.
S p im lin a J e n n e ii. Kutz. Tab. Phyc. i., t. 37, j . 11.
Trichomes more or less elongated, distinctly articulated,
spirals lax, distant, joints equal in length to tbeir diameter, or
a little shorter. Cell-oontents pale or bright blue green.
S iz e . Trichomes •007--008 mm. diam.
Eabh. Alg. Eur. i., 90. Kirch. Alg . Sohl. 250.
Spirillum Jenneri, Hass. Alg. 277, t. 75, f. 5.
Arthrospira Jenneri, Hedwigia i., p. 82, t. 5.
In stagnant water.