lineari-ligulate, attenuated at base, often stipitate, longitudinally striate, each stria marked with a series of bi-quaternate granules. Hook. Br. Fl. ii. p. 312. Bangia calophylla, Carm. in Grev. Crypt. Fl. t. 220.

On damp stones, rocks &c. Lismore Island, Appin, Capt. Carmichael. Near Limerick. North of Ireland, Mr. D. Moore.-This forms a bright green, thin stratum. Frond minute, 3 or 4 lines long, linear strap-shaped, obtuse, tapering at base, or suddenly contracted into a cylindrical stipes, much waved and curled, very variable in breadth. Granules quaternate, closely covering the frond, set in longitudinal rows, of which two or more (sometimes half-a-dozen) form the breadth of the frond; interstices colourless.

XCI. BANGIA. Lyngb.

Frond flat, capillary, membranaceous, of a green, reddish or purple colour. Fructification: granules arranged more or less in a transverse manner. Grev.-Name, in honour of Hofmann Bang, a Danish botanist.

1. B. fusco-purpurea, Lyngb. ; filaments elongated, capillary, decumbent, nearly straight or somewhat curled, equal, forming a brownish-green or purple stratum, glossy; granules few (about five) in each transverse line. Grev. Alg. Brit. p. 177; Hook. Br. Fl. ii. p. 316; Wyatt, Alg. Danm. No. 167. Conf. fusco-purpurea, Dillw. t. 92; E. Bot. t. 2055. Conf. atro-purpurea, Dillw. t. 103; E. Bot. t. 2085.

On rocks and wood in the sea, near high-water mark; not uncommon. -Forming a lubricous, blackish-purple, occasionally greenish stratum. Filaments several inches long, straight or curled, variable in breadth; the narrow ones appearing to be cylindrical, and containing often but a single row of granules; the broader, flat or compressed, containing 4 or 5 rows. Granules large, dark purple, square, closely set. Mrs. Griffiths, who remarks the affinity of this plant with Lyngbya, "always finds it cylindrical.” In such minute objects it is not always easy to judge, from the appearance presented by the microscope, whether a thread is round or not. To my eye the wider threads appear to be flat, the narrower cylindrical and consisting of a single row of cellules. These latter are strikingly similar to Lyngbya.

2. B. ciliaris, Carm.; "filaments gregarious, very minute, simple, straight, compressed, purple; granules binate, globose." Carm. MSS.; Hook. Br. Fl. ii. p. 316.

On the old leaves of Zostera marina, Appin, Capt. Carmichael. Annual. Spring."This, the minutest of all the Bangia, grows on the edges of the leaves in the form of a delicate pink-coloured fringe. Filaments half a line in length, gelatinous, straight, compressed, rather torulose. Granules large, globular, arranged in pairs." Carm.— The granules are occasionally in a single series.

3. B.? Laminariæ, Lyngb.; filaments tufted, short, rigid,

cylindrical, obtuse, olive-green; granules (often indistinct), set in double rows, each of about four. Hook. l. c. p. 316. In the sea, parasitical on Alaria esculenta. Frith of Forth, Drs. Greville and Arnott. Arran, Clare, Messrs. Ball and Thompson. Antrim, Mr. Moore. On Ulva Lactuca at Appin, Capt. Carmichael.-Tufts minute, stellate or pencilled. Filaments from a quarter to half an inch long, straight, cylindrical, equal, or slightly broader upwards, very obtuse, of a dull olive-brown colour, transversely banded. Bands more or less evident, containing a double row of granules. Mr. Moore correctly remarks that this plant has no natural affinity with Bangia, but rather belongs to the Dictyotea, where it has many points in common with Asperococcus ? pusillus, a plant whose generic affinities are equally doubtful. Perhaps a genus might be formed of these two. For the present, however, I leave them where my predecessors have placed them, as the fructification of neither seems very clearly made out.

4. B. lætevirens, Harv.; filaments minute, tufted, flexuous, attenuated upwards, bright green, flat; fascia close, composed of innumerable minute granules. Hook. Br. Fl. ii. p. 317.

On old fronds of Enteromorpha intestinalis, at the extreme verge of highwater mark, Miltoun Malbay, Ireland. Annual. Summer.-Filaments minute, simple, 2 or 3 lines in height, tufted, many in the same tuft, lubricous, bright yellow-green, tapering to a subacute point, flaccid and slightly curved. Transverse bands rather broad, close, evidently containing granules, but so minute and numerous, that it is impossible accurately to examine them. It is conspicuous on the old dull-coloured fronds of the Enteromorpha, by its bright green hue. This, too, is a very doubtful species of Bangia, but I know not where else to place it.

5. B. lacustris, Carm. ; "filaments scattered, decumbent, branched, deep green, the branches divaricated, acute; fascia of ternate, globose granules.” Carm. MSS. cum icone;

Hook. l. c. p. 317.

On the submerged leaves of aquatic plants, Appin, Capt. Carmichael. Annual. Summer.-" Filaments not exceeding a line in length, of a deep green colour, scattered, tortuous, creeping, and apparently fixed at or near the centre, attenuated at both ends and divaricately branched; sporidia globular, arranged in transverse series of 3 in the same filament, and 2 in the branches." Carm.-This is a very doubtful production, which I believe Capt. Carmichael only once found. Perhaps it belongs to the animal kingdom. With Bangia it has only an artificial connection.

XCII. ENTEROMORPHA. Link.

Frond tubular, hollow, membranaceous, of a green colour and reticulated structure. Fructification three or four roundish granules, aggregated in the reticulations. Grev.Name, EVTEPOV, the entrail, and μopîn, a form or appearance.

1. E. Cornucopiæ, Carm.; gregarious, small; fronds tubular at the base, dilated upwards, plaited, laciniated and torn at the margin. Carm. MSS.; Hook. Br. Fl. ii. p. 313. Scytonema intestinalis, ß. Cornucopiæ, Lyngb. p. 67.

On corallines &c. in rocky pools left by the tide. Annual. Spring and summer.-" Fronds gregarious, about an inch long, funnel-shaped, from a short, tubular base, expanding into a plaited, laciniated membrane, torn and jagged at the extremity. Granules in fours, all over the frond. lour dark green below, pale above.” Carm.

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2. E. intestinalis, Link; fronds elongated, simple, inflated, (often floating). Grev. Alg. Brit. p. 179; Hook. 1. c. p. 313; Wyatt, Alg. Danm. No. 80.-B. crispa; frond compressed, the margin crisped and curled. Grev.

An

In the sea, and in brackish and fresh-water ditches, very common. nual. Summer.-Fronds often 2 feet long or more, and from a line to 2 or 3 inches in diameter, tapering at base, at first fixed by a minute root, afterwards detached and freely floating, inflated, variously waved or curled, of a full green colour, fading to yellowish and finally white.

3. E. compressa, Grev.; fronds elongated, branched, cylindrical or sub-compressed; the branches simple or nearly so, long, and much attenuated at their base. Grev. Alg. Brit. p. 180, t. 18; Hook. l. c. p. 314; Wyatt, Alg. Danm. No. 165. -B. prolifera; frond somewhat inflated, throwing out capillary branches on all sides. Grev.

On rocks &c. in the sea, very common. Annual. Spring and summer. -Fronds 6-12 inches long, either capillary or several lines in diameter, more or less branched, sometimes nearly simple, sometimes very much divided and bushy; branches generally springing near the base, much attenuated below, gradually widening upwards and obtuse at the tips, by which character this variable plant is easily recognised from the four following.

4. E. Linkiana, Grev.; "frond cylindrical, tubular, filiform, reticulated, pellucid, of a very pale green colour, membranaceous, (rigid when dry), much branched; branches attenuated." Grev. Alg. Brit. p. 182; Hook. l. c. p. 314.

In the sea. Appin, Capt. Carmichael. Annual. Summer." Fronds 6-12 inches in length, filiform, cylindrical, tubular, inflated, rising with a main stem about 1 line in diameter, on all sides of which, and along the whole length, the branches are inserted: branches 2-6 inches long, smaller in diameter than the stem, between erect and spreading, set with a second series, 1 or 2 inches long, which, in their turn, bear a third, which are quite capillary. The structure distinctly reticulated, the reticulations roundish, but angular. Fructification: 3 or 4 subglobose granules within many of the reticulations. Substance membranaceous, but firm and somewhat cartilaginous when dry, adhering very imperfectly to paper. Colour a very pale, yellowish green." Grev. l. c.

5. E. erecta, Hook.; frond cylindrical, filiform, slender,

highly reticulated; branches erect, opposite or alternate, set with capillary ramuli, all attenuated to a fine point. Hook. Br. Fl. ii. p. 314; Wyatt, Alg. Danm. No. 166. E. clathrata, B. Grev. Alg. Brit. p. 181. Conferva paradoxa, Dillw., (authentic specimen); Griff. MS.

In the sea, about half-tide level. Annual. Spring and summer. Appin, Capt. Carmichael. Frith of Forth, and Bute, Dr. Greville. Torquay, in deep water, Mrs. Griffiths.- Frond 4-8 inches high, cylindrical, from the thickness of a hog's bristle to half a line in diameter; stem generally undivided, closely set with opposite or alternate, simple branches, which diminish in length upwards; these are gradually attenuated to a point, and set throughout with sub-distichous, slender, setaceous, erecto-patent ramuli, 1 or 2 lines long, and all tapering at the tips, which give the plant a feathery appearance. Such is the normal state of this species, but there are numberless varieties, which seem to connect it with the following, as that in like manner is connected with E. ramulosa; and I quite agree with Sir W. J. Hooker, who, in adopting Capt. Carmichael's descriptions, says, that however distinct typical individuals of the three supposed species may appear, still "that there are intermediate states of these plants which would rather lead me to coincide with Dr. Greville, and to unite them." Few plants are so sportive in size and ramification, and if all the varieties were described the species might easily be multiplied till we should have one for almost every marine pool!

ton.

6. E. clathrata, Grev.; frond cylindrical, filiform, slender, highly reticulated; branches spreading, much divided, set with divaricated or recurved ramuli. Grev. Alg. Brit. p. 181; Hook. Br. Fl. ii. p. 315; Wyatt, Alg. Danm. No. 34? E. clathrata, a. Grev. l. c. Conf. paradoxa, E. Bot. t. 2328. In the sea. Annual. Spring and summer. Belfast Bay, Mr. TempleAppin, Capt. Carmichael. Brighton, Mr. Borrer. Torquay, Mrs. Griffiths. Not uncommon.- Frond 4-12 inches high, cylindrical, from the thickness of a bristle to 1 or 2 lines in diameter, generally with an undivided stem set with close branches, which spread in all directions and bear a second, third, or fourth series, till the plant assumes a very bushy appearance; the ramuli slender, abundantly scattered, either spreading or curved back, occasionally tangled and interwoven, their apices always acute and tapering. Carmichael describes this plant as prostrate, " forming a thin, inextricable fleece," a state evidently approaching the following.

7. E. ramulosa, Hook.; frond compressed, highly reticulated, very much branched and interwoven, twisted, every where covered with spine-like branchlets. Grev. Alg. Brit. p. 181; Hook. l. c. p. 315; E. Bot. t. 2137. E. clathrata, Y. Grev. l. c. E. ramulosa, var. minor, Wyatt, Alg. Danm.

No. 208.

In the sea. Annual. Spring. Bantry Bay, Miss Hutchins. Plymouth, Mr. Sconce. Appin, Capt. Carmichael.- "Fronds 5 or 6 inches to 1 or 2 feet long, half a line in diameter, compressed, curled and twisted, much and repeatedly branched, and interwoven into a (more or less) thick and inex

176

ENTEROMORPHA-TETRASPORA-PALMELLA.

tricable mat, and beset on all sides with short, spine-like branchlets, or rather apiculi, which render it harsh to the touch. Substance membranaceous, green. This species can be at once distinguished from E. clathrata, with which alone there is any risk of its being confounded, by mere handling, the one feeling harsh to the touch, the other soft and silky." Carm. MSS ́·

8. E.? percursa, Hook.; "frond very slender, capillary, compressed, marked with spurious reticulations, and a central longitudinal line." Carm. MS.; Hook. l. c. p. 315.

On the oozy sea-shore, above the half-tide level, and giving it a greenish hue to an indefinite extent: Appin, common, Capt. Carmichael. Annual. Spring and summer.-I am not acquainted with this plant, which seems an intruder in the genus.

XCIII. TETRASPORA. Link.

Frond either tubular, inflated or flat, gelatinoso-membranaceous, of a green colour. Fructification: minute granules, mostly arranged in fours.-Name, TETpa, four, and σñoρɑ, a seed; in allusion to the distribution of the seeds.

1. T. gelatinosa, Desv.; frond ovate, inflated, very gelatinous. Hook. Br. Fl. ii. p. 313.

In fresh-water streams, attached to aquatic plants. Mucruss, Killarney. Botanic Garden, Belfast, Dr. Drummond.-Fronds exceedingly lubricous and gelatinous but firm, delicately waved and plaited, of an ovate outline. Sporules bright green, arranged in fours, or scattered.

2. T. lubrica, Ag.; frond quite simple, tubular, sub-gelatinous, waved and sinuated. Hook. Br. Fl. ii. p. 313.

In gently running streams, at first attached to water-plants. Hellesdon, Norfolk, Sir W. J. Hooker. Appin, Capt. Carmichael. Castlemartyr, Cork, Miss Ball. Frond larger than in the preceding, less gelatinous, and with a more distinct membrane; the tube finally ruptures and the plant becomes flat, with an irregular outline. Agardh has observed the seeds to have, at the moment of being discharged, a spontaneous motion resembling that of animalcules, and of the seeds of various other fresh-water Algæ.

XCIV. PALMELLA. Lyngb.

Plant a shapeless gelatinous mass, filled with scattered globular or elliptical granules. -Name, aλuos, vibration; from the loosely gelatinous nature of these plants. The granules are sometimes arranged in fours, in which case the line of distinction between Palmella and Tetraspora vanishes.

* Fronds green.

1. P. protuberans, Ag.; frond thick, irregularly lobed,