4
Trichomes compact, densely interwoven at the periphery,
joints cask-shaped, or compressed sphærioal, close together,
uniform. Heterocysts subglobose. Spiores oval, with a thick
tegument, smooth.
S iz e . Joints -OOJ-'OOS mm., heterocysts -006 mm., spores
•005 X •OO? mm.
Born. & Thuret Notes Alg. p. 108. Rabh. Alg. Eur. No.
746. Harv. Man. 184. Gray Arr. i., 352. E n g . El. v., 400.
Hass. Alg. 289, t. 76, f. 5 (?). Dickie Bot. Guide, 310.
Nostoc vesicariwn, Menegh. Nost. Ital. p. 108 (not Harvey).
Ulva pisiformis, Huds. Fl. Ang. ii., 572.
In springs and mountain rivulets.
“ Fronds from half a line to two lines in diameter, globular, firm,
smooth, solid, heaped on each other like a parcel ot small shells. Internal
filaments rather thinly scattered throngh the mass.”—Carmichael.
Plate XCI. jiy. 8. Nostoc sphæricum nat. size ; fig. 9, triohome x 400 ;
fig. 10, portion of trichome x 600; fig. 11, spores x 600.
N o s to c lu p e s tx e . Kutz. Spec. Alg. p. 296.
Fronds soft, globose, olive, becoming brownish, often forming
an irregular crust.
Trichomes much spaced out, of unequal size, joints nearly
sphærical, sheaths often coloured, contrasting with the generally
uncoloured jelly. Spores oval with a smooth tegument.
S iz e . Jo in ts -005--008 mm., heterocysts •007 mm.
Rabh. Alg. Enr. ii., 163. Thuret Notes Alg. p. 112. Borzi
Alghe Pico. p. 283.
Nostoc microscopicnm, Carm. Harv. Eng. F l. ii., 899. Harv.
Man. 184. Mack. Hib. 245.
On rooks, overrunning mosses, &c.
This species is mixed up by Hassall with Nostoc muscorum, if it be not
in reality the whole of that species, for there is some doubt whether N.
muscorum, as defined by Bornet and Thnret was known to him.
Plate XCI. jig. 12. Involved trichomes of N. rupestre x 400 ; figs. 13,
14, 16, young plants in course of development x 400, after Borzi.
N o s to c m a c io sp o x um . Meneg. Mon. Nost. 116, t. 14, f . 2.
Fronds very small, punctiform, æruginous-green, or brownisli-
olive.
Trichomes large, bluish-green, or brownish, joints cylindrical,
a little constricted at their junction. Sheaths broad, brownish
or yellowish-brown. Heterocysts globose. Spores globose with
a smooth tegument. .
S iz e . Jo in ts -008-^009 mm., heterooysts -009--01 mm.
Born & Thuret Notes Alg. p. 112. Eabh. Alg. Eur. ii., 163.
Hass. Alg. 298, t. 73, f. 1, 2. Borzi Alghe Fico. p. 283.
Hormosiphon macrosporus, Kutz. Tab. Phyc. ii., t. 13, f. 1.
Diplocolon Heppii, Itzig. Phyc. Stud. t. 11, f. 8-12,
Nostoc pyreniacum, Ripart. Bull. Soc. Bot. F r. (1868.)
Nostoc ichthyon, Eabh. Alg. Eur. ii., 164.
On rocks among moss.
Plate XCII.jigs. 1, 2. Involved trichomes of N. macrosporum x 400 ;
fig. 3, development of hormogone, x 400, after Borzi.
N o s to c c æ ïu le um . Lyngi. Hydr. Dan.t. 68,/. b.
Fronds, small, globose or subglobose (-1 to 4 lin e s), fixed or
free swimming, usually gregarious, blue or greenish-blue.
Trichomes dissimilar, unequal, joints of two forms, th e one
(young) elongated, the other larger, nearly sphærical, sometimes
filled with opaque granules.
S iz e . Joints -004--007 mm., heterocysts -008 mm.
Born. & Thuret Notes Alg. p. 114. Rabh. Alg. Eur. ii., 167.
Nord. & W ittr. Alg. Exs. No. 98. Grev. Sc. Crypt. Fl. 1 .131.
Hass. Alg. 293, t. 76, f. 11, t. 75, f. 10, t. 74, f. 1. Eng. Fl.
V . , 400. Harv. Man. 183. Gray Arr. i . , 352.
Nostoc ccerulescens, Rabh. Alg. Eur. ji., 168.
Nostoc Itzigsohnii, Rabh. Alg. Eur. ii., 168.
On mosses and submerged plants.
Plate XCII. fig. 4. Plants of Nostoc cæruleum natural size ; fig. 5.
trichomes x 400; fig. 6, portion of triohome x 600.
N o s to c p ru n ifo rm e . Ag. Disp. A lg . p. 45.
Frond from th e size of a pea to th a t of a damson, or larger,
olive or dark mruginous-green, when old becoming blackish-
brown, with a coriaceous periderm, and watery within.
Trichomes loosely interwoven, joints snbglobose, compressed,
closely connected. Heterocysts globose, usually terminal.
S iz e . Joints -004--005 mm., heterooysts -006--007 mm.
Born. & Thuret Notes Alg. p. 1 1 6 . Rabh. Alg. Eur. ii.
Kutz. Tab. Pby. ii., t. 4 , f. 4. W itt. & Nord. Alg. Exs. 97',
2 7 6 . (?) Berk. Glean, t. 19 , f. 2. Hass. Alg. 2 9 1 , t. 7 6 , f.
3 , 4 . Eng. Fl. V., 8 9 9 . Harv. Man. 1 8 3 . Gray Arr. i., 3 5 2 .
Ulva pruniformis, Huds. Aug. ii., 572. Abbot. Bedf. 274.
With. Arr. iv., 120. Hull. Br. Fl. 310._
Nostoc coccymelon, Kutz. Tab. Pbyc. ii., t. 4, f. 3.
I l l freshwater pools, rivulets, &c.
Plate XCII. fig. 7. Nostoc pruniforme, natural size ; fig. 8, trichome
y 4D0; fig. 9, portion of trichome, with spores in course of formation
X 600.’