NOSTOCE. 229 
‘Nostoc carneum. 4g. Syst. Alg. p. 22. 
Frond indefinitely expanded, bullate and undulate, flesh 
coloured, rufescent or purplish. 
Trichomes loosely interwoven, joints equal, sheath none, in- 
distinct, or uncoloured, spores oval. 
Size, Joints :0037--004 mm., heterocysts ‘006 mm. diam., 
spores (006 x °009 mm. 
Rabh, Alg. Eur. ii., p. 180. Born. and Thuret, Notes Alg. p. 
91. 
Nostoc variegatum, Harv. Man. 183. Kutz. Sp. Alg. 301. 
Hass. Alg. p. 287, t. 74, f. 3. 
Nostoc purpurascens, Kutz. Tab. Phyc. ii., t. 11, f. 4. 
Nostoc rufescens, Ag. Syst. 22. Rabh. Alg. Eur. ii., 179. 
On rocks, 
“First collected in Ireland in 1836, growing on the face of a moist 
bank over which water trickled. When recent it formed a soft gelatinous 
mass, of a livid colour, bearing the closest resemblance, both in substance 
and colour, to those gelatinous medusz which are cast ashore along the 
coast.’—Moore. 
Plate XC. fig. 1. Nostoc carneum, natural size; fig. 2, trichomes 
X 400; fig. 3, development of spores X 600. 
II. Genatinosa, Fronds soft and gelatinous, adherent, joints of 
trichome cylindrically elongated in the young filaments, Spores 
oblong, large. 
Nostoc spongieforme, Ag. Syst. Alg. p, 22. 
Frond at first subglobose, then indefinitely expanded, be- 
coming rather firm, pale #ruginous or olive green, surface 
tuberculated. 
Trichomes heterogenous, composed of two sorts of joints, one 
cylindrical the other cask-shaped, or compressed spherical. 
Heterocysts globose. Spores smooth, oblong. 
Sizz. Joints ‘004 mm., heterocysts -007-:008 mm., spores 
‘006--007 x 01-012 mm. 
Born, & Thuret Notes Alg. p. 92. Rabh. Alg. Eur, ii. 178. 
Kutz. Tab. Phye. ii, t. 9, f. 4. 
Nostoc inundatum, Kutz. Spec. Alg. 299. Rabh. Alg. Eur. 
ii, 171. 
” Hormosiphon inundatum, Kutz. Tab. Phye. ii, t. 27, f. 2. 
Hormosiphon stagnalis, Kutz. Tab, Phye. ii, t. 27, f. 3. *¢ 
Hormosiphon natans, Kutz. Tab. Phye. ii., t. 27, f. 4. 
In wet or inundated places. 
Plate XC. fig. 4. Nostoe spongieforme, natural size; fig. 5, young 
trichome ; fig. 6, mature trichome X 400; fig. 7, portion of mature 
trichome X 600, 
