I
ri
I
N ëm a io o e nÆ .
S p izu lin a o sc illa r io id e s. Turp.
Solitary, or forming little green tufts, sometimes almost
radiating. Trichomes more or less elongated, nearly erect, pale
blue green, twisted in lax or dense spirals, endowed witb active
motion.
S iz e .—Trichomes •0015--Ü02 mm. diam.
Kutz. Tab. Pbyc. i., t. 37, f. 8 . Rabh. Alg. Eur. ii., 91.
Kircb. Alg. Scbl. p. 250. Cohn Nova Acta xxiv., t. 15, f.
15.
var. b. m in u tiss im a . Rabh. Alg. Ev,r. ii., 91.
Trichomes abbreviated, more loosely spiral.
Spirillum minutissimum, Hass. Alg. 278, t. 75, f. 8 .
Spirulina brevis, Kutz. Tab. Phyo. i., t. 37, f. 9.
In fresh, brackish, or thermal waters.
Plate X C V I . fig. 3. Portions of trichomes X 400. Fragment
further magnified.
S p iru lin a ten u is sim a . Kutz. Spec. Alg. 236.
Forming a membranaceous, lubricous, dark blue green floating
stratum, trichomes very thin, flexuous, very densely spiral, endowed
with active motion ; joints very indistinct.
Siz e .—Trichomes very thin. Spirals -005 mm. diam.
Rabh. Alg. Eur. ii., 92. Harv. Phyc. Britt, t. 105, f. c.
In brackish ditches.
Floating in large blue green masses on the surface of brackish ditches.
The threads are too delicate for measurement, and appear only as lines
under a magnifying power of 400 diameters.
Flate XOVI. fig. 2. Portions of trichomes X 400.
Genus 101. OSCILLARIA. Bose. (1800.)
Trichomes simple, usually distinctly articulate, rigid, straight,
or a little curved, rarely circinate or spirally convolute, for the
most pa rt brightly coloured (blue-green, steel-blue, violet,
æruginous, &c.), motile,nestling in a matrical mucilage; joints
disc-shaped in tbe front view, without a sheath distinct from
the trichome.
Consult Dr, d’Alquen in Quart. Journ. Micr. Soi. iv. (1856), p. 245.
The species are at present distinguished hy very artificial characters,
which are by no means permanent, in which respect the genus is notin a
much better condition than it was forty years ago.
Osc illarla tenerrima. Kutz. Tab. Phye. i., t. 38, f. 8.
Solitary and scattered, or associated in fascicles. Trichomes
straight, indistinctly articulate, joints eqnal in length to their
diameter, or a little longer or shorter, ends somewhat acute,
slightly inclined ; cell-oontents pale blue green, or olive, homogenous
or very finely granular.
S iz e . Threads •0018--0025 mm. diam.
Eabb. Alg. Eur. ii., 96.
In ditches, amongst decaying vegetable matter.
Plate XCVI. fig. 4. Trichomes X 400.
Osc illa r ia lep to tr ich a . Kutz. Tab. Phyo. i., t. 38, f. 9.
Solitary, scattered, or collected in a very thin blue green
stratum, triobomes very slender, slightly curved, indistinctly
articulate, joints twice as long as broad, or after division equal,
very minutely punctate at the periphery, attenuated at the ends,
which are straight, curved, or deflexed, cell-contents pale blue,
green, homogenous or finely granular.
S iz e . Threads -003 mm. diam.
Eabh. Alg. Eur. ii., 97.
In fresh or brackish ditches.
Plate XCVI. fig. 5. Trichomes X 400.
var. splen d id a . (Grev. Fl. Edin. 304./
S iz e . Trichomes not exceeding -002 mm. diam.
Oscillatoria splendida, Eng. Fl. v., 375. Harv. Man. 164.
Hass. Alg. 251, t. 72, f. 8 .
In tubs of water in a stove. Edinburgh Botanic Gardens.
Plate XCVI. fig. 6. Trichomes X 400.
Osc illaria sp ir a lis . Carm. Harv. Phyo, Britt, t. 105b.
Effused in a firm coriaceous glossy black stratum. Trichomes
radiating, slender, long, flexuous, regularly twisted in spirals.
Size. Threads -OOSfi-'OOI mm. diam.
Spirillum rupestre, Hass. Alg. 277, t. 75, f. 6 .
re, Eabh. Alg. Eur. ii., 93.
On rocks by the seaside.
" I t spreads over the dry naked earth. Stratum several feet in extent,
firm, coriaceous, of a glossy black colour, void of lubricity. Filaments
about balf a line in length, twisted like a corkscrew, radiating iu all directions.”—
Carmichael.
Plate XCFIII. fig. 7. Trichomes X 400, from the original specimens.