The English flora - SeaweedAfrica

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392 ALGjE GLOlOCLADEiE. [Rivularia.
globose smooth firm glossy-black, filaments deep-green slender
dichotomous. Ag. Syst. Alg. p. 24. E. Bot. t.
On marine rocks, plants, &c, very common.
1798.
2. R. batryoides, Carm. {grape-like Rivularia); fronds minute
aggregated roundish wrinkled ferruginous cartilaginous, filaments
dichotomous.
In streamlets, attached to rocks and stones, Captain Carmichael.—
" Fronds about a line in diameter, hemisphaerical, wrinkled and cartilaginous,
scattered or running together like a bunch of grapes. Filaments
cohering firmly, obscurely striated, dichotomous. Colour, when fresh,
black; on drying, darkly ferruginous." Carm. MSS.
3. R. Pisum, Ag. (sphcerical Rivularia); frond globose
smooth soft shining dark-green, filaments dichotomous Ag.
Syst. Alg. p. 25. Berk. Alg. t. 2. f.
2. Linkia dura, Lyngb.
Hydroph. Dan. t. 67. Grev. Crypt. Edin. (according to Mr.
Arnott.)
On aquatic plants, in subalpine streamlets.— " Fronds a line in diameter,
scattered or confluent, of a dark-green colour and fleshy firmness.
Filaments radiating from the base, dichotomously branched and attenuated
to a point ; striae inconspicuous." Carm. MSS.
4. R. applandta, Carm. (flattened Rivularia); fronds minute
gregarious orbicular depressed black, filaments simple attenu-
ate the apices free.
On rocks and stones, in the sea, common. Appin, Capt. Carmichael.—
" Fronds a line in diameter, gregarious, often confluent, circular, depressed,
spongy, of an opaque black colour, shrinking, splitting and becoming
grayish on drying. Filaments one-fourth of a line in length,
simple, attenuated to a point, loose at the apex, of a bluish-green colour."
Carm. MSS.—This minute plant is probably common on every rocky
coast, though hitherto overlooked. It differs from R. atra in its depressed
form, and simple filaments.
5. R. plicdta, Carm. (wrinkled Rivularia); fronds rather
large densely gregarious gelatinous compresso-plicate often
hollow and ruptured dark-green, filaments many times dichotomous
attenuated.
On the sea-shore about high-water mark, or in situations where it is
only occasionally inundated with salt-water. Appin, Captain Carmichael.
Torbay, Mrs. Griffiths. Eyemouth, Dr. Johnston. Innischerig Island,
Clare, W. H. Harvey.— " Fronds growing from a smooth gelatinous
stratum, from a line to half an inch in diameter, mostly confluent and
distorted by mutual pressure, gelatinous, and in their more advanced
state, often hollow and ruptured. Filaments dichotomous, tapering to a
fine point, obscurely striated. Globules few in number, pellucid, lodged
within the filaments, which at length break off, leaving the globule attached
to the base of the dismembered branch.
6. R. calcdrea, Sm. (stony Rividaria); fronds large orbicular
convex, at length aggregated into a broad spongy crust, zoned
within, at length petrified. E. Bot. t. 1799. Ag. Syst. Alg.
p. 26. R. haematites, Dec. and Duby, (according to Mr. Arnott.)
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