BRITISH SEA-WEEDS. LONDON: 3ISHOPSGATF. STRF.K1 MANUAL BRITISH MARINE ALGM GENERIC AND SPECIFIC DESCRIPTIONS OF ALL THE KNOWN BRITISH SPECIES OF SEA-WEEDS. WITH PLATES TO ILLUSTRATE ALL THE GENERA. WILLIAM HENRY HARVEY, M.D., M.R.I.A. KEEPER OP THE HERBARIUM OF THE UNIVERSITY OF DUBLIN ; AWD PROFESSOR OF BOTANY TO THE ROYAL DUBLIN SOCIETY. LONDON : JOHN VAN VOORST, PATERNOSTER ROW. M.DCCC.XLIX. " Vere magna et longe pulcherrima sunt etiara ilia, profundissima sapientia hie exstructa opera tua, OH JEHOVAH! quee non nisi bene arraatis nostris oculis patent! Qualia autein eruntdenique ilia, qua sublato hoc speculo, remota mortalitatis caligni, dalurus es tuis, Te vere sincere pectore colentibus ! Eheu qualia !" — Hedivig. MRS. GRIFFITHS, OF TORQUAY, DEVON, A LADY WHOSE LONG-CONTINUED BESEAKCHES HAVE, MOEE THAN THOSE OF ANY OTHEK OBSEEVEE IN BRITAIN, CONTRIBUTED TO THE PRESENT ADVANCED STATE OF MARINE BOTANY, AND WHOSE NUMEROUS DISCOVERIES, COMMEMORATED IN THE GENUS GRIFFITHSIA, ENTITLE HER TO THE LASTING GRATITUDE OF HEE FELLOW-STUDENTS, THIS VOLUME, WHICH OWES MUCH OF WHATEVER VALUE IT MAY POSSESS TO HER LIBERAL DONATIONS OF EARE SPECIMENS, AND HER ACCURATE OBSEEVATIONS UPON THEM, IS BESPECTFULLY INSCBIBED, BY HER FAITHFUL AND OBLIGED FBIEND, THE AUTHOR. Trinity College, Dublin, June 30, 1849. 2090895 ADVERTISEMENT TO THE SECOND EDITION. EIGHT years have now elapsed since the publication of the first edition of this work, and during this period much has been done, both in this country and on the Continent of Europe, to further our acquaintance with the Algae. Many new species have been discovered, — the natural result of a greater attention to the subject ; and much has been done to advance our knowledge of the structure and fructifica- tion of these plants. From both circumstances have re- sulted many improvements in classification ; and if we admit that much still remains to be done before our classi- fication can be considered perfect, we may also congratu- late the numerous company of British Algologists on the progress that has been made in illustrating their favourite branch of study, and on the flourishing condition to which it has arrived. In the present edition an improved distribution of the marine species, particularly of the Red sea-weeds (Rhodo- spermeae) has been, it is hoped, introduced. I have been forced, however, to omit the fresh-water Algae, which were included in the first edition, for two reasons : first, because they have recently been treated at large in a separate work, by a cotemporary; and secondly, because my attention has been so exclusively turned to the marine Algae, whilst viii ADVERTISEMENT. engaged on the Phycologia Britannica, now in course of publication, that I have not had sufficient leisure to study the fresh-water species with the care that their intricacy demands. No great changes have been made in the descriptive portions of the work, with the exception of improved ge- neric and specific characters where such improvement seemed needed ; and the introduction, at the commence- ment of each Order, of short descriptions and remarks in illustration of the variations in habit observed among the species, their geographical range, and anything peculiar connected with their history. The general Introduction has been, with some small corrections, for the greater part, retained ; very little has been added, but several passages have been struck out, the substance of which will be found embodied in the in- troductory observations prefixed to the orders. The most important improvement in this new edition consists in the plates to illustrate the genera. These, it is hoped, will be found sufficiently full to enable the student, with the help of the descriptions, to ascertain the genus to which any sea-weed he may find belongs. It is not intended, in a work like the present, to give full analytical or anatomical details in such figures, but sufficient analysis is given for practical purposes. Trinity College, Dublin, June 30, 1849. PORTRAIT OF PROFESSOR HARVEY. IT was the intention of the Publisher to have prefaced this volume with a portrait of the Author. The Author's absence in the New World prevents this until his return, which is not expected before Midsummer, 1850. As soon after this time as the engraving can be finished, the Publisher will deliver the print, free of charge, in exchange for this notice, which purchasers of the work are solicited to sign and present, either direct, or through their respective Book- sellers. JOHN VAN VOORST. Paternoster Eow, London, December 20, 1849. INTRODUCTION. WHOEVER has paid the slightest attention to the classifica- tion of natural objects, whether plants or animals, must be aware, that if we desire to follow natural principles in form- ing our groups, — that is, to bring together such species as resemble each other in habit, properties and structure, — it is a vain task to attempt to define, with absolute strictness, the classes into which we are forced to combine them. At least, no effort to effect this desirable object has yet been successful. Natural groups are so interwoven into each other, and often exhibit such an exaltation and degradation of characters within the limits of an Order or a Genus, that the distinctive marks, as they approach each other, gradually disappear, and two tribes, which in the more highly developed species scarcely resemble each other, are found, in the lower, to be either undistinguishable or with difficulty distinguished. Thus, to a common observer, the Poppy and the Fumitory would scarcely be supposed to be closely related ; yet there is so much gradation be- tween them, through allied genera, that some botanists have placed them in the same Natural Order. Still more unlike in appearance are the Rose and the Shamrock, yet they belong to Orders so closely connected, that the only invariable mark by which they can be distinguished is, that in one, what is called the odd segment of the calyx is posterior, while in the other it is anterior ; and till this X INTRODUCTION. was pointed out by Mr. R. BROWN, botanists were at a loss to define the respective orders, though very seldom indeed puzzled as to whether a genus were Rosaceous or Legumi- nous. If it be thus difficult to define groups among highly organized plants, it can be no matter of wonder that when we come to the CRYPTOGAMIA, whose structure is so much more simple and uniform, and whose forms are still more sportive, the difficulties become vastly increased. But it fortunately happens that these difficulties are much more formidable on paper than in the field. Thus, while the system-maker, in his study, may puzzle his brains with the fruitless task of attempting to express in words a diagnostic which shall include every species of the class ALG.E, and, at the same time, exclude every denizen of the allied groups, FUNGI and LICHENES ; the student, roaming through the fields or along the sea-shore, finds no difficulty what- ever in recognising a sea-weed, as distinct from a mush- room or a Lichen. The search into structure and affini- ties among the works of creation is something like that after first principles. We can distinguish and analyse up to a certain point : there we are stopped by that invisible and intangible, but impassable veil, behind which the Creator hides his operations. At this point we must rest satisfied with differences which we can see, but which we cannot know or define. Dismissing, therefore, specula- tions on the exact limits between ALG.E and all other tribes, let us proceed to consider the subject more imme- diately before us, namely, the habit, structure, geographi- cal distribution and uses of these plants. The name ALG^I, under which the LICHENS were for- merly included, is now limited by botanists to that large group or Natural Class of Cryptogamic or floWerless plants, which forms the principal and characteristic vege- INTRODUCTION. XI tation of the waters. The sea, in no climate from the po- lar circle to the equator, is altogether free from Algae, though they abound on some shores much more than on others, a subject which will come particularly under notice when we speak of the distribution of their several tribes. Species abound likewise in fresh water, whether running or stagnant, and in mineral springs. The strongly impreg- nated sulphureous streams of Italy, — the eternal snows of the Alps and arctic regions, — and the boiling springs of Iceland, have each their peculiar species ; and even che- mical solutions, if long kept, produce Alga?. Very few, comparatively, inhabit stations which are not submerged or exposed to the constant dripping of water ; and, in all situations where they are found, great dampness, at least, is necessary to their production. Thus extensively scattered through all climates, and ex- isting under so many varieties of situation, the species are, as one would naturally suppose, exceedingly numerous, and present a greater variety in form and size than is ob- servable in any other tribe of plants whose structure is so similar. Some are so exceedingly minute as to be wholly invisible, except in masses, to the naked eye, and require the highest powers of our microscopes to ascertain their form or structure. Others, growing in the depths of the great Pacific Ocean, have stems which exceed in length (though not in diameter) the trunks of the tallest forest trees ; and others have leaves that rival in expansion those of the Palm. Some are simple globules or spheres, con- sisting of .a single cell or little bag of tissue filled with a colouring matter ; some are mere strings of such cells co- hering by the ends ; others, a little more complex, exhibit the appearance of branched threads ; in others, again, the branches and stems are compound, consisting of several such threads joined together ; and, in others, the tissue Xii INTRODUCTION. expands into broad flat fronds. Only the higher tribes show any distinction into stems and leaves, and even in these, what appears a stein in the old plant, has already served, at an earlier period of growth, either as a leaf, as in Sargas- sum and Cystoseira, or as the midrib of a leaf, as in Deles- seria. A few exhibit leaves or flat fronds formed of a delicate, perforated net-work, resembling fine lace or the skeletons of leaves, a structure which is also found among zoophytes. Of those so constructed, the most remarkable are the New-Holland genus Thuretia, the East-Indian Dictyurus (Callidictyon, Grev.), and Martensia, a genus lately discovered at Port Natal, in South Africa, by Dr. Krauss, which produces fan-shaped fronds, the lower half of which has the structure and colour of Nitophyllum, the upper that of the delicate net-wrork of Thuretia. Claudea, one of the most singular of all the Algae, has a reticulated frond of somewhat different structure. In this plant the phyllodia are not formed by the simple interlacement of fibres, or the perforations of a membrane, but by the anas- tomosing of minute, ribbed leaflets, which are at first free, and gradually connect their points with the rib of the leaf- let next above them. The new originate all at the upper side of the older leaflets, and stand at right angles with them; thus a net-work is soon formed, and as the distances between the leaves are small, the structure is delicately lacy. Among British Algae, the only structure analogous to these exists in Hydrodictyon, a fresh water Alga, which grows in the form of a perfect net, with regular meshes. The substance of which the frond consists is as variable as the form. Some are mere masses of slime or jelly, so loose that they fall to pieces on being removed from the water ; others resemble, in feel and appearance, threads of silk ; some are stiff and horny ; others are cartilaginous, INTRODUCTION. xiH or with the aspect and elasticity of gristle ; others tough and coriaceous, or resembling leather ; while the stems of some of the larger kinds are almost woody. The leaves of some are delicately membranaceous, glossy and trans- parent ; of others, coarse and thick, and either wholly des- titute of nerves, or furnished with more or less defined ribs, or beautifully veined. Several have the power of withdrawing carbonate of lime from the water in which they grow, and laying it up, in an organized state, in their tissues. Among fresh-water species, particularly of the Rivularia, we find the first imperfect exhibitions of this remarkable power, but in some of these the lime occurs in such lumpy masses, that it may perhaps rather be regarded as an incrustation, through which the plant continually grows. In the marine Corallines, and in several of the orders Siphonaceae and Batrachospermacea, the secreting process is too perfect for the lime to be considered as an incrustation. It is obviously necessary to the perfect de- velopment of the vegetable. Some of the least perfect of the Corallines, the Melobesia or Nullipores, resemble masses of calcareous matter, not at all unlike the incrusta- tions formed in water strongly impregnated with carbonate of lime ; but when we place these apparent rocks into acid for a short time, until the lime is partly dissolved, there re- mains a delicately cellular structure, of the full form and size of the original mass, and built in a perfectly regular manner. In the cells of this body, and the interstices be- tween them, the particles of lime had been arranged. Among the most minute kinds, many (comprising the family Diatomacea} are cased with organized silex, and these cases, which resist the action of fire, are found in countless myriads in a fossil state, in many countries, cover- ing miles of ground, or forming mountains, and presenting XIV INTRODUCTION. to the naked eye a whitish, powdery substance, known by the name of " mountain meal." In colour, the Algae exhibit three principal varieties, with, of course, numerous intermediate shades, namely, grass-green, olivaceous, red. The grass-green is character- istic of those found in fresh water, or in very shallow parts of the sea, along the shores, and generally above half-tide level ; and is rarely seen in those which grow at any great depth. But to this rule there are exceptions, sufficiently numerous to forbid our assigning the prevalence of this co- lour altogether to shallowness of water. Several of the more perfect Conferveae and Siphoneae grow beyond the reach of ordinary tides ; and others, as the beautiful Ana- dyomene, are sometimes dredged from very considerable depths. The great mass, however, of the green-coloured species, are inconsiderably submerged. The olivaceous- brown or olive-green is almost entirely confined to marine species, and is, in the main, characteristic of those that grow at half-tide level, Algae of this colour becoming less frequent towards low-water mark ; but an olivaceous vege- tation frequently occurs also at greater depths, in which case it is very dark, and passes into brown or almost black. The red also, is almost exclusively marine, and reaches its maximum in deep water. When red sea-weeds grow above half-tide level, they assume either purple, or orange, or yellow tints, and sometimes even a cast of green, but in these cases their colour is sometimes brightened by placing the specimens, for a short time, in fresh water. The red is rarely very pure much within the range of extreme low- water mark, higher than which many of the more delicate species will not vegetate ; and those that do exist degene- rate in form as well as in colour. How far below low- water mark the red species extend has not been ascertained, INTRODUCTION. XV but those from the extreme depths of the sea are of the olive series in its darkest form. For the colours of these last it has puzzled botanists not a little to account. It is well known that light is absolutely necessary to the growth of land-plants, and that the green colour of their foliage altogether depends upon its supply : if placed in even par- tial darkness they quickly acquire a sickly yellowish hue, and finally become white. But with Algae it is different. At depths to which the luminous rays, it is known, do not penetrate, species exist as fully coloured as those along the shore. They therefore, in this respect, either differ from all other plants (FuNGi included), or perhaps, what are called the chemical rays, in which seem to reside the most active principles of solar light, may be those which cause colour among these vegetables, and may penetrate to depths to which luminous rays do not reach. But this is mere supposition. However this may be, it is worth remarking that this property among Algae, of producing vigorous growth and strong colour without the agency of light, af- fords another link between them and the animal kingdom, among the lower tribes of which light is by no means es- sential to growth and the most brilliant colour. There is this difference also in the distribution of colours among Algae to what obtains among other plants. Among plants in general, nothing is so variable or uncertain as colour : far from serving as a mark to distinguish groups or genera, colour does not even aspire to the rank of a spe- cific character, and the utmost to which it can pretend is to separate one variety of a species from another. Among Algae, on the contrary, it has been ascertained that the classes of colour enumerated above, are, to a great extent, indicative of structure, and consequently of natural affinity. Thus, the green species are of the simplest structure, and XVI INTRODUCTION. differ remarkably in their mode of propagation from either of the other tribes, their spores being endowed at the period of germination with a sort of motion, which some have called voluntary, but which does not really possess that animal property. The olivaceous are the most perfect and compound in the structure of th^ir organs of vegetation, and reach the largest size ; and the red form a group dis- tinguished not less by the beauty and delicacy of their tissue, than by producing spores under two forms, thus pos- sessing what is called a double fructification. Hence, modern botanists, since the publication of Lamouroux's system, have, whatever their particular views of arrange- ment may be, almost invariably used colour as one of the principal characters on which their systematic arrangement is based ; and to a great extent it may be safely trusted. But the young student must be careful not to place too absolute dependance on colour alone, in referring plants which he may gather to their place in the system ; for some species, which in their healthy state are red, or of that class of colour, become, when growing under unfavourable circumstances, of an orange, yellowish, whitish, or greenish shade. Laurencia pinnatifida is particularly variable in this respect. When this species grows near low- water mark, it is of a fine, deep, purple-red ; a little higher up it is dull purple-brown ; higher still a pale brownish red, and, at last, near high-water mark, it is often yellowish or greenish. The other species of Laurencia vary in similar but less striking degrees. Chondrus crispus too, when found in shallow water, exposed to strong sunlight, is often of a bright herbaceous green ; and Ceramium rubrum passes through every shade of red and yellow, and at last degene- rates into a dirty white, before it ceases to grow. All these species vary in form and size, as they do in colour, and the INTRODUCTION. XVli various anomalous shapes that they assume are almost sure to deceive a young botanist into the belief that the varieties are so many different species. Many Algae, whilst growing under the surface of the water, reflect colours which perish almost immediately after they are removed to the air. Of this class are several spe- cies of Cystoseira, especially C. ericoides, which, though really of a greenish olive, appears, when growing under water, to be clothed with the richest phosphoric greens and blues, changing momently, as the branches move to and fro in the water. Similar colours have been observed, though in a less striking degree, on some species of the red series. The genus Iridcea derives its name from this character, though our /. edulis is not remarkable in this respect. Miss Ball and Mr. W. Thompson have observed Chondrus crispus to be occasionally iridescent. At the Cape of Good Hope, Champia compressa and Chylocladia capensis present very brilliant rainbow colours. Miss Hutchins observed that Conferva Hutchinsics has change- able glaucous tints when fresh, and looks almost white when seen through the water. The cause of these brilliant colours has not been particularly sought after. There are other species which really change colour shortly after their removal from the water, as the various kinds of Sporochnoideae, which pass rapidly from a clear olive to a verdigris-green. But this is the effect of death and incipient decomposition, for with the colour they lose their crispness, become flaccid, and emit an offensive odour, and, as has been observed by botanists, possess the remarkable property of changing the colour of other small filiform Algae with which they may come in contact. No doubt this is owing to the development of some active chemical agent. Professor Mertens, in describing the cir- cumstance as occurring with Desmarestia ligulata and b Xviii INTRODUCTION. D. aculeata, says, that these species remain unaltered while they cause decay around them. But this I have not found to be the case. The Desmarestia always loses its rigidity, and its original olive is changed to verdigris before it possesses any destructive power. The Fucoidecs become black on exposure to the air. The Laminaria, on the contrary, first become green and finally white, under simi- lar circumstances. Many of the Floridete are much bright- ened in colour after having been cast upon the beach, especially if exposed to rain and sunshine. Amongst those of our own shores, Plocamium coccineum and Dasya ooc- cinea are conspicuous in this respect. Both are, originally, of a dull, deep pink, but when thrown up and a short time exposed, become of a veiy rich scarlet-crimson. But Ge- lidium cartilagineum, so common at the Cape of Good Hope, often presents the most splendid gradation of colour in a single specimen, from dull purplish pink (its original dye) through scarlet, orange, yellow, and verdigris-green to white ; to which colour all the red and green species may be bleached after long exposure. Among the more delicate tribes several are instantly al- tered by being plunged into fresh water. Nitophyllum versicolor, as Mrs. Griffiths has observed, is remarkable in this respect; its full pink being instantly changed to a bright orange. Delesseria hypoglossum and ruscifolia have the same peculiarity, as have many of the Callithamnia and Griffithsia, and other delicate Rhodosperms. All these changes are accompanied by decomposition. In the case of Griffithsicn* especially, shortly after the change, the co- louring matter of the joints is abundantly discharged with a crackling noise through the ruptured membrane, staining with a beautiful carmine colour the water or the paper to * See an excellent description of this in a paper by Dr. Drummond, of Belfast, in ' Mag. Nat. Hist.' vol. ii. p. 121. INTRODUCTION. XIX which the specimen has been removed. No doubt a fine lake could be prepared either from G. setacea or multifida, could they be procured in sufficient quantity. Paper stained by them retains its colour after many years in the herbarium. At the Cape of Good Hope there is a species of Callithamnion (C. purpuriferum), which, when grow- ing, is of a dull, deep, grayish brown, with but a slightly reddish hue ; but the moment it is placed in fresh water it discharges an abundance of fine, brilliant, purple pow- der, and almost immediately becomes flaccid and putrid. The beautiful Thorea ramosissima, lately discovered by Mr. Mc'Ivor in such abundance in the Thames, at Walton Bridge, is at first of a dark olive, but gradually acquires, after it has been dried, a purple tint. Many of the Polysi- phonice also, which are, when growing, of a brown colour, become, in fresh water, purple or pink ; while some of the same group, as Rytiphlaa complanata, &c., which are at first red, give out, in fresh water, quantities of blackish brown juice, and would become wholly black if dried with- out long previous steeping. Heat converts the colour of most species to green. If any of the Fucacew be plunged in boiling water they rapidly assume a bright green, but, on removal, revert to their original olive, and finally to black. The colours of the Rhodosperms may be more per- manently changed, and also to green, by similar treatment. Dictyotaceae perhaps are less affected by fresh water, either cold or hot, than any others. Some of them are nearly un- changed ; others assume more or less of a green shade. Most Algae are, at some period of their growth, found attached to other substances by means of a root, or at least a hold-fast. It has been doubted whether, as no distinct vessels of absorption have been discovered, they receive any nourishment through this organ, but the question is by no means settled. Thus much is at least certain : some XX INTRODUCTION. Algae appear to be as much influenced by the soil in which they grow as other plants are, and a large number of those that are parasitical confine themselves to particular species. This selection of habitat would seem to prove that the root is not so sluggish an organ as it has been supposed to be. It does not, however, present much modification, and rarely attains a large size. The usual form is that of a hard, callous disk ; sometimes this is accompanied by fleshy fibres ; and occasionally, but rarely, the root consists of an extensive creeping mass of fibres. This latter form is most remarbable in the genus Catilerpa, the species of which grow on sand, and consequently require the support of an extensively ramified, penetrating and compact root. Some species, which, under ordinary circumstances, are attached by roots, occasionally dispense with them, and continue to flourish independently of them. Of these the most remarkable are Sargassum bacciferum and vulgare (?), which, under the Spanish name " Sargasso," or the English " Gulf-weed," have forced themselves on the notice of all voyagers who have crossed the Atlantic since the time of Columbus. The vast fields of sea-weed which were met with by " the adventurous Genoese " and his early follow- ers, which made the ocean appear like a meadow, and sen- sibly impeded the course of their small vessels, consisted of these species. According to Humboldt there are two principal banks ; one, the largest, extending from the 25th to the 36th degree of north latitude, and a little west of the meridian of Fayal, one of the Azores ; the other, which is much smaller, a short way west of the Bahamas, and be- tween the 22nd and 26th degrees of latitude. These localities of the banks, however, can but be considered as approximations, for with plants that float about wherever the winds and currents drive them no very certain station can obtain. Vessels returning from the Cape of Good INTRODUCTION. XXI Hope, sometimes, in these latitudes, pass through immense fields of sea-weed ; and others, though steering exactly the same course, and at the same season, meet with scarcely any. 1 have made the voyage four times, and only once met with sea-weed in sufficient quantity to claim any attention. It did not then occur in strata resembling fields, but rather in ridges, from ten to twenty yards broad and of great length, stretched across the sea. The species invariably found in these was S. bacciferum. Of a large quantity that we dredged up for several successive days not a particle be- longed to S. vulgare, and I am much inclined to suspect that most, if not all, of the stories related by voyagers as of that species, belong to *S". bacciferum, a plant which has never been found in any other situation than floating about in the deep sea, whereas S. vulgare (the Focus natans of Turner) is well known in many tropical countries to grow on the rocks, within the reach of the tide, like others of the genus. It is therefore much to be regretted that the name of natans was not retained for S. bacciferum, to which it is chiefly, if not only, applicable. Authors who have written on this Fucus have much disputed, both respecting its ori- gin and whether it continues to grow whilst floating about. Nothing at all bearing on the former question has yet been discovered, for though species of Sargassum abound along the shores of tropical countries, none exactly corresponds with S. bacciferum. That the Ancestors of the present banks have originally migrated from some fixed station is probable, but farther than probability we can say nothing. That it continues to flourish and grow in its present situa- tion is most certain. Whoever has picked it up at sea, and examined it with any common attention, must have perceived not only that the plants were in vigorous life, but that new fronds were continually pushing out from the old, the limit being most clearly defined by the colour, xxii INTRODUCTION. which in the old frond is foxy-brown ; in the young shoots pale, transparent olive. But how is it propagated ?— for it rarely produces fructification. It seems to me that the old frond, which is exceedingly brittle, is broken by accident, and the branches, continuing to live, push out young shoots from all sides. Many minute pieces that I examined were as vigorous as those of larger size, but they were certainly not seedlings, and appeared to me to be broken branches, all having a piece of old frond from which the young shoots sprung. As the plant increases in size it takes something of a globular figure, from the branches issuing in all direc- tions, as from a centre. On our own shores we have two species analogous to S. bacciferum in their mode of growth, namely, Fucus Mackaii, and the variety /3. sub-ecostatus of Fucus vesiculosus, (F. balticus, Ag.) Neither of these has ever yet been found attached, though they often occur in immense strata; the one on the muddy sea-shore, the other in salt marshes ; in which situations, respectively, they continue to grow and flourish. And if it be hereafter shown that F. Mackaii is merely F. nodosus, altered by growing under peculiar circumstances, may it not be in- ferred that S. bacciferum — which differs about as much from S. vulgare as F. Mackaii does from F. nodosus — is merely a pelagic variety of that variable plant ? In structure, whilst there is a great variety among the different tribes of Algae, we find, in material points, a per- fect similarity among all. All consist of simple cellular tissue, or of its elements, gelatine (or organic mucus), mem- brane, and endochrome (or chlorophyll), variously elabo- rated and perfected. No vessels or ducts have been discovered in any, nor does woody fibre, though of com- mon occurrence among the Fungi, exist in the Alga. The gelatine (or mucus) is perfectly transparent in all, but differs greatly in consistency in different species, but without much INTRODUCTION. XXlll regard, seemingly, to the comparative perfection of the structure of which it forms a part. It is often as lax and as slimy in some plants of the higher tribes as in those of lower organization, and some of the latter have it as firm and consistent as any of the former. Thus the frond of Champia and Chylocladia among Laurenciacese is filled with a watery gelatine ; that of Splachnidium among Fu- caceae with a loose, slimy matter ; whilst Rivularia among Oscillatoriaceae has a singularly firm and consistent jelly. In Mesogloia it is Very loose, investing the threads of which the frond is composed with a lubricous sheath. In Gigar- tina, Chondrus, &c., it is so firm as to give those plants the consistence of cartilage, and in these it is immediately dissolved in hot water, opening to us a curious and unex- pected affinity between them and Mesogloia ; for if a branch of any Gigartina be plunged into hot water it will be con- verted, by the dissolving of its gelatine, into one having all the characters of the frond of the former genus. Thus we find that there is no fundamental difference in the structure of the frond of these two apparently dissimilar genera, but that one has a firmer gelatine than the other. The cellular tissue of Alga? presents some varieties. The most common form of the cell is cylindrical, often of very small diameter in proportion to its length ; and, in such cases, the cells always cohere by the ends into threads or filaments, bundles of which, either branched or simple, form the frond by lateral cohesion. The fronds of many of the simple kinds, Confervea, Ceramics, &c., consist of a single thread, or string of cells or joints. Those which are more compound may generally be resolved into such threads by macerating small portions, either in hot water, or, if that prove ineffectual, in diluted muriatic acid. If a branch of a Fucus (say F. tuberculatus) , be so treated, and a thin longitudinal slice be then examined with the micro- INTRODUCTION. scope, it will be found to consist of four distinct portions concentrically arranged, which Lamouroux, who first ob- served minutely the anatomy of these plants, compares, perhaps too fancifully, to the epidermis, bark, wood, and medullary sheath of exogenous plants. The central por- tion, corresponding to the medulla, occupies fully a third of the diameter of the branch, and is composed of densely packed, longitudinal, parallel fibres, or strings of cells, firmly cohering into one compact mass. Outside this is a much less dense layer, of a paler colour, composed of branched, anastomosing fibres, partly horizontal and partly vertical, inextricably laced together ; and surrounding these, which represent the wood, is a third and much denser and darker coloured layer (bark), which is altogether composed of horizontal, radiating, simple fibres, very densely packed together. Outside this portion, and form- ing the outer coat of the frond, is a very thin layer of cells, which is frequently but loosely attached, and separates much in the manner of an epidermis. Something similar to this, which we may call the analogy of the Exogenous type among Algae, is the structure of many of the larger kinds, both of the red and olive series, but minor variations occur in the comparative substance of the different layers. Thus, in some the centre is very loose and gelatinous, with merely a few scattered fibres, while the outer coat is very dense. The second circle (that representing wood) is ne- ver, I believe, so dense as the others, and very generally consists of branched, interlacing and colourless fibres, and from it fructification generally, if not always, proceeds. Another common form of the cell is that of an irregular, very rarely regular, polygonal solid, resulting from the lateral and vertical pressure of a mass of spherical cells. This form is found generally in the Ulvce, and in most spe- cies having large expanded leaves, especially among the INTRODUCTION. XXV Rhodospermese, where both stems and leaves are often composed of a homogeneous mass of such cells packed to- gether. In fructification we find many modifications of struc- ture, without much real difference either in the manner in which the fruit is perfected or in the spore that is produced. The spore that is finally formed in all the Algae appears pretty nearly to agree in structure, and to consist of a single cell or bag of membrane, filled with a very dense and dark coloured granular or semifluid mass, called the endochrome. This spore, on germination, produces a perfect plant, re- sembling that from which it sprung. Nothing at all resem- bling floral organs has been noticed in any, and all that we know of the fructification is, that it takes place with regularity, arising from the same parts of the frond, and having the same appearance in plants of the same kind. Its growth maybe watched from the commencement, when the germ of the future spore begins to swell. But little has been ascertained that throws light on the process of fecundation. In some instances, it is true, as for example in Zygnema, the spore is formed from the union of the matter contained in a cell of one filament with that in a cell of another, and it has been observed that the cells of one filament uniformly give out, and that those of another uniformly receive ; but before conjugation no difference whatever can be perceived between the two filaments. This, which occurs in a tribe of very low organization, af- fords the nearest analogy that has yet been noticed with what takes place in higher plants. If it have any real affinity with that process, we may fairly expect the disco- very of sexes in the more perfect tribes ; and the seeming analogues of male flowers have indeed been noticed in some of these. Old authors invested the air-vessels of Fticus, or the tufts of hairs that clothe the surface of some INTRODUCTION. species with this character; but both opinions have been long since given up as untenable. The recent observations of Messrs. Decaisne and Thuret* have shown the existence, in the Fuci, of organs similar in many of their characters to what are supposed to be the male organs of Mosses, Charte, Hepaticcc, &c. The little bodies called by these authors antheridia (a name now adopted) had been previ- ously observed, and referred, under the name acrospores, to the female system of the plant. They are found in the spherical conceptacles of the Fucus, either in those which also contain spores or in others, which they exclusively oc- cupy, and which do not differ from female conceptacles in any other character than by their contents. The antheri- dia are little transparent cases, each formed of a cell, borne on branching threads, that form little tufts springing from the sides of the conceptacle. At maturity the antheridia fall off from their stalks, and then appear more or less filled with orange-coloured granules of very minute size. After a time these granules escape, and immediately commence most lively movements, strikingly similar to those observed in the spores of the Chlorosperms. Under very high pow- ers of the microscope each corpuscle is found to be fur- nished with two active cilia or hairs, which are its organs of motion. The shape of these little bodies is different from that of the spermatozoa found in the supposed anthers of the Mosses and Hepaticee, but their motion by means of cilia is very similar, and there seems no reason to doubt their analogy with those objects. They are best observed in winter, at which season many of the fronds of Fucus serratus and F. vesiculosus will be found covered with orange-coloured or bright yellow receptacles. If some of the brightest coloured fruits are selected and allowed * In the ' Anuales des Sciences Naturelles.' INTRODUCTION. XXV11 partially to become dry, drops of an orange, viscid liquid will ooze out of the pores of the conceptacles, and collect on the surface. If a small portion of this fluid, diluted by a drop of sea water, be now placed under the microscope, it will be found to consist of myriads of detached antheri- dia, in all stages of fullness, among which troops of sper- matozoa will be seen performing their strange gyrations. Such is the nature of the supposed male system of the Fuci. Its analogy with the antheridia of the mosses is obvious, but observations are still wanting to show that the spermatozoa in either case have any connexion with the fecundation of the spores. If we limit our assertions by the present state of our actual knowledge on the subject, all that we can state with certainty is, that in those cases where the formation of spores among Algae has been most closely watched and most successfully observed, the spore has resulted from the union of the contents of two cells. That a transmission of the endochrome from one cell to another, prior to the formation of spore, occurs in all the compound Algae, seems probable from the fact that the cells immediately surrounding the spores are always co- lourless and empty, but there is nothing as yet known to prove that one cell is less adapted than another to receive the endochrome, and form the future embryo, — nothing to show that there is any clear distinction into male and female. Experiments on the propagation of Algae from their spores have not yet been so frequently made as the interest of the subject deserves. In our own country, I am not aware that any one since Mr. Stackhouse, in 1796, has attempted it. This gentleman attempted to grow some of the Fuci, and so far succeeded with F. canaliculatus as to witness the germination. The following account of his experiment, which I extract from his ' Nereis BritannicaJ though INTRODUCTION. already more than once published, may prove interesting to those who have not seen it, and perhaps tempt botanists whose residence near the sea gives them an opportunity, to repeat the trial. " Having procured a number of wide- mouthed jars, together with a siphon to draw off the water without shaking or disturbing it, on Sept. 7, 1796, I placed my plants (F. serratus, canaliculatus and tuberculatus) carefully in the jar, with their bases downwards, as in their natural state ; on the following morning I decanted off the sea water, and, letting it subside in the basin, I found a few particles at the bottom, which on being viewed with the microscope appeared to be little fragments detached from the surface by friction in carriage. I then poured a fresh quantity of sea water on the plants, and placed them in a window facing south : on the following morning the jar containing the plants of F. canaliculatus discharged into the basin a few yellowish grains, which, on examining them, I found to be the actual seeds of the plant ; they were rather oval than pear-shaped, but the most curious circum- stance attending the observation was, that each individual seed was not in contact with the water, but enveloped with a bright mucilaginous substance. Tt was easy to guess the wise economy of nature in this disposition, which, as hinted above, serves a double purpose ; each equally necessary towards continuing the species. On the following morning a greater quantity of seeds were discharged by this plant, and at this time a few seeds were procured from F. serratus ; but this latter plant discharged such a quantity of mucous fluid that the sea water in which the plant was immersed was of the consistence of syrup, and consequently, the seeds being kept suspended, it was difficult to separate them. The seeds of F. canaliculatus, however, were numerous, and visible to the naked eye, and after letting the water rest for a few minutes it was no difficult matter, by gently INTRODUCTION. XXIX inclining the basin, to pour off the water and let the seeds remain. In performing this operation I was witness to an explosion or bursting of one of these seeds or pericarps, which agitated the water considerably under the microscope, and brought to my recollection the circumstance mentioned by Major Velley during his investigation of F. vesiculosus. I at last obtained a discharge of seeds likewise from F. bifurcatus (luberculatus) ; these perfectly resembling the others. Having established this point, viz., that marine plants scatter their seeds in their native element without violence when ripe, and without awaiting the decay of the frond, I next procured some sea pebbles and small frag- ments of rock, taken from the beach, and having drained off the greater part of the water in the jar, I poured the remainder on them, and left them dry for some time that the seeds might affix themselves. I then fastened strings to the pebbles, and alternately sunk them in sea water in a wide-mouthed jar and left them exposed to the air, in or- der to imitate as nearly as possible their peculiar situation between high and low-water mark, and when the weather was rainy I took care to expose them to it. In less than a week a thin membrane was discoverable on the surface of the pebble where the seeds had lodged, with a naked eye ; this gradually extended itself, and turned to a darkish olive colour. It continued increasing in size, till at last there appeared numerous papillae or buds coming up from the membrane : these buds, when viewed with a glass, were ra- ther hollow in the centre, from which a shoot pushed forth : in some instances they seemed on a short, thick footstalk, and in this latter case resembled in some measure the pezizae-formed seedling of F. loreus, and the others without stems were like the stemless Pezizte. These plants conti- nued to put forth the central shoots for some time, but their growth was not rapid after the first efforts; most XXX INTRODUCTION. probably owing to their confined situation ,- and as I was six or eight miles from the sea, and had not the opportunity of placing the pebbles in some of those pools which are left by the sea at low water, I discontinued the experiment." It is much to be regretted that Mr. Stackhouse, in con- ducting the above experiment, did not make more use of the microscope. We are not told how the membrane pro- ceeded from the spores, nor whether the sprouts arose from each single spore, or from several associated. More recently, on the continent, M. J. G. Agardh, son of the celebrated Swedish algologist and worthy successor to his chair, has made more minute observations on the germination both of spores and of tetraspores, of several species, and has published magnified figures of the young plants in various stages of development. His memoir on this subject will be found in the ' Annales des Sciences Naturellesy for October, 1836 ; and I shall here extract some of its more interesting matter. According to him, whatever may have been the shape of the spore before it issued from the capsule, it soon acquires a spherical form, and is then undistinguishable from the tetraspores of the same species, which likewise germinates in the same manner. In his figures, for I regret to say he has not detailed the whole process, nor given an account of his method of pro- ceeding with the plants, he has represented the first effort of germination as showing itself by the spore acquiring an oval form; a minute papilla then issues from one end, which elongates and becomes the root; the upper end likewise pushes in an opposite direction, gradually elon- gating, and increasing in diameter by the production of new cells, till at length it acquires the character of the species. He has figured the germination of the spores and tetraspores of Ceramium rubrum and Laurencia pinnatifida, and of the spores of Fucus vesiculosus ; to all which the above INTRODUCTION. XXXI applies. But the most interesting part of the memoir is, the account given of some curious circumstances attending the germination of some of the lower Algae, those belonging to the grass-green series, (Chlorospermece, Nob., Zoosper- mej, a girdle or zone. 1 . Z. parvula, Grev. ; frond procumbent, attached by fibres issuing from its lower surface, membranaceous, suborbicular, variously lobed ; lobes free, rounded, scarcely marked with concentric lines. Grev. Alg. Brit. p. 63 ; Hook. Br. FL ii. p. 282 ; Grev. Crypt, t. 360. On rocks and corallines, between tide-marks, and in 4 — 15 fathom water. Annual? Spring and summer. All round the coast. — .Fronds spreading over the rocks in patches, one to several inches in diameter, attached by means of whitish fibres, except at the margins, which are free and lobed ; the lobes rounded, smooth, entire, often imbricated. The substance is membranous, somewhat transparent, and highly reticulated; the cells quadrangular. The colour is an olivaceous green. The fructification has not yet been observed in Britain, but is described, on Swedish specimens, by Dr. Areschoug. V. TAONIA. J. Ag. [Plate 7, B.] Root coated with woolly fibres. Frond flat, ribless, im- perfectly fan-shaped, irregularly cleft, highly reticulated, marked with concentric lines. Fructification : linear, wavy, concentric, superficial sort, on both surfaces of the frond, consisting of clustered, naked spores, destitute of filaments. Scattered spores occupy the intermediate spaces. Name, raajv, a peacock. 1. T. atomaria, Good. & Woodw. ; frond membranaceous, broadly wedge-shaped or somewhat fan-shaped, deeply and irregularly cleft and laciniated ; spores forming waved, trans- verse lines, with intermediate scattered ones. Grev. Alg. Brit. p. 58 ; Hook. Br. FL ii. p. 280 ; Wyatt, Alg. Damn. No. 60; E. Bot. t. 419; Harv. Phyc. Brit. t. i. DICTYOTA — STILOPHORA. 39 Rocks between tide-marks, rare. Annual. Summer. East and south of England. Frith of Forth, Grev. Ballycotton, coast of Cork, Miss Ball. — Fronds tufted, 3 — 12 inches long, with a broadly wedge-shaped or palmate outline, triangular at base, deeply cleft into numerous segments, which are again divided into lesser ones, the apices truncate. The colour is a brownish- olive ; the substance thin and transparent, and the whole surface beautifully marked with broad wavy lines of dark brown spores, from a quarter to half an inch asunder, the intermediate spaces mottled with scattered groups of spores. VI. DICTYOTA. Lamour. [Plate 7, A.] Root coated with woolly fibres. Frond flat, ribless, mem- branaceous, reticulate, dichotomous or pinnatifid ; the surface cells parallel, those at the apices of the segments converging. Fructification : roundish, scattered sori, bursting through the cuticle on both surfaces of the frond, consisting, at matu- rity, of numerous, obovate, tufted spores; or, on distinct plants, solitary, scattered spores. Name, SMTVOV, a net, be- cause the surface is reticulated. 1. D. dichotoma, Huds. ; frond regularly dichotomous, linear ; the segments becoming gradually narrower towards the extremities ; spores scattered irregularly or clustered. — Grev. Alg. Brit. p. 57, /. 10; Hook. Br. FL ii. p. 280; Wyatt, Alg. Danm. No. 10 ; E. Bot. t. 774 ; Harv. Phyc. Brit, t. ciii. — 8. intricata, Grev. ; frond very narrow, much branched, twisted and entangled. On rocks and sea plants in the sea, between tide-marks, and in 4 — 15 fathom water. Both varieties common. Annual. Summer. — Fronds 3 — 12 inches long, 1 — 4 lines wide, of a clear olive-green colour and mem- branous substance, regularly dichotomous. Spores either scattered over the surfaces, or (in distinct plants) collected into dense spots. VII. STILOPHORA. J. Ag. [Plate 7, C.] • Root a small, naked disk. Frond filiform, solid or tubular, branched. Fructification : convex, wart-like sort scattered over the surface, composed of obovate spores nestling among moniliform, vertical filaments. Name, On mud-covered rocks near low-water mark, rare. Abundant on the Pier at Torquay, Mrs. Griffiths. Whitsand Bay, Dr. Jacob. Wicklow, W. H. H. Balbriggan, Miss Gower. Smerwick Harbour, Mr. Andrews. — Stems tufted, 1 or 2 inches high, simple or with 3 or 4 branches, setaceous, opaque, inar- ticulate, striate with veins, densely covered with ramuli, which are specially crowded round the tips of the branches, giving them a strikingly obtuse appearance. Ramuli 3 — 5 lines long, slender, erect, several times forked, the apices elongated. Joints of the ramuli long. Colour a brownish or bright purple. Stichidia lanceolate, acuminate, nearly as long as the ra- muli, sessile or shortly stalked, containing dark purple granules, closely set in transverse bands. These receptacles are commonly produced ; the cap- sules have not yet been found in this country. 3. D. drbuscula, Dillw. ; stems much and irregularly branched, beset on all sides with short, divaricating, dichoto- mous ramuli, whose articulations are about twice as long as broad ; stichidia oblong, with a mucro. Ag. Sp. Alg. ii. p. 121 ; Harv. Phyc. Brit. t. ccxxiv. Conf. Arbuscula, Dillw. t. G. (excl. syn. Brownii, and Dillw. t. 85). D. Hutchinsice, Harv. in Hook. Br. Fl. ii. p. 335. On rocks in the sea. Not uncommon on the shores of Ireland and Scotland. Eemarkably h'ne at Bantry, Miss Hutchins. — Stems 2 — 4 inches high, tufted, much branched ; branches alternate, bearing a second or third series, and densely clothed with dichotomous, divaricate ramuli, about a line in length, which give the plant a rounded appearaace; tips of the branches blunt. Colour generally a pale reddish brown, sometimes deep red; substance flaccid. Capsules ovate, with a much-produced, sub-cylin- drical point, containing pear-shaped spores. Receptacles oblong, suddenly acuminate, or obtuse with a mucro, containing two or three rows of ternate granules. Very distinct from the last in habit and character. 4. D. venusta, Harv. ; frond pyramidal, decompoundly pinnate; the branches clothed with exceedingly slender, flaccid, many times dichotomous, attenuated ramuli, whose articulations are five or six times as long as broad; stichidia pedicellate, ovoid, much acuminate ; ceramidia ovate-urceo- late, with a protruding mouth. Harv. Phyc. Brit. t. ccxxv. Cast on shore, in summer. Annual? Very rare. Jersey, Miss White and Miss Turner. — Stem 3 — 4 inches high, as thick as a hog's bristle, un- divided, furnished with numerous alternate, lateral branches, the lowest of which are longest, the rest gradually shorter upwards. Branches pinnated with a second or third series. Stem bare of ramuli, but all the branches LAURENCIACE^:. 95 and their divisions clothed with very slender, hair-like, dichotomous, single- tubed rarnuli. Colour a fine rose-red. Substance very flaccid and tender, closely adhering to paper. A beautiful species, with the habit of Seirospora Griffithsiana, more than of any British species of Dasya. ORDER VIII. LAURENCIACE^ * Laurencieae, Hook. fil. and Harv. Lond. Journ. vol. iv. p. 539. Chondrieae, J. Ag. Alg. Medit. p. 67. Harv. Ner. Austr. p. 7. Lomentarieae, Endl. 3d SuppL p. 42. Chon- drieae (partly), Chondrosipheae, Champieae, Kuiz. Phyc. Gen. pp. 435, 438, 439. Lomentareae, Lindl. Veg. King. p. 25. DIAGNOSIS. — Rose-red or purple sea-weeds, with a cylin- drical or compressed, rarely flat, linear, narrow, areolated, inarticulate or constricted and chambered, branching frond, composed of polygonal cells. Fructification double: l,con- ceptacles (ceramidid) external, ovate, furnished with a termi- nal pore, and containing a tuft of pear-shaped spores ; 2, tetraspores immersed in the branches and ramtili, scattered without order through the surface cells. NATURAL CHARACTER. — Hoot sometimes a simple disk, but very frequently branching. Frond mostly cylindrical, rarely compressed, and still more rarely flattened, destitute of mid- rib, linear, usually preserving nearly the same breadth through- out, branching; the branches most generally pinnate, some- times whorled, sometimes tufted, and sometimes (but very rarely) dichotomous. In the typical genera (such as Lauren- da and Bonnemaisonia] the frond is solid, the whole substance composed of polygonal cells closely packed together, and there is no trace of articulation or regularly recurring con- striction. But in some genera (as Chylocladia, Champia, * This order is usually called Chondriea, a name objectionable on two grounds. First, the genus Chondria, Ag., is suppressed, being synonymous with Laurencia, L.. the typical genus; and, secondly, the sound Chondritce or Chondriacea recalls Chondrus, which is a genus belonging to Cryptone- miacece. I therefore propose a name taken from the original, and most widely dispersed genus of the order. 96 LAURENCIACEjE. &c.) the branches are usually hollow, and constricted at regular intervals into joint-like portions, furnished at each constriction with a diaphragm, which divides the cavity into separate chambers : these chambers are filled with mucous matter, through which a few vertical filaments, connecting the diaphragms, are dispersed. In other genera (as Chrysy- menid) the frond is also hollow and full of mucus, with a few filaments dispersed through it ; but in these there are neither constrictions nor diaphragm, but each branch consti- tutes a chamber. Such genera evidently connect the two extreme forms of the order. The ceramidia are sometimes imperfectly organized, and reduced nearly to the structure of coccidia, the pore being indistinct. The contents, however, appear to be constantly pyriform spores, tufted as is normal in this kind of concepta- cle. The tetraspores are sometimes collected near the tips of the ramuli, but very commonly they are dispersed through the branches in a very indefinite manner. On this dispersion is founded the chief technical character by which the order is distinguished from Rhodomelacete, but in habit there is between the two groups that difference which marks a natural family. The colours of the Laurenciacea are often fugacious. In Laurencia itself, the prevalent colours are shades of purple, but in most other plants of the order they are pink or lake-red. When exposed to sunshine all become yellowish, and most lose their colour in fresh water. None turn black in drying. The genera of this order, and many of the species, are re- markable for their wide dispersion, the same forms inhabiting the most distant countries. Thus, all of our Laurencia are natives also of the Southern Ocean ; and L. pinnatifida is equally common in the Pacific and Atlantic basins, in both temperate and tropical climates. SYNOPSIS OF THE BRITISH GENERA. I. BONNEMAISONIA. Frond solid, filiform, (rose-red), much branched ; the branches margined with subulate, dis- tichous cilia. [Plate 12, B.] II. LAURENCIA. Frond solid, cylindrical or compressed, (purplish or yellowish), pinnatifid; the ramuli blunt. [Plate 12, C.] BONNEMAISONIA — LAURENCIA. 97 III. CHRYSYMENIA. Frond hollow, filled with watery mu- cus, neither constricted nor chambered. [Plate 13, A.] TV. CHYLOCLADIA. Branches hollow, filled with watery mucus, constricted at intervals, and chambered. [Plate 13, B.] I. BONNEMAISONIA. Ag. [Plate 12, D.] Frond filiform, inarticulate, compressed or plane, solid, much branched, the branches margined with distichous, awl- shaped, alternate cilia. Fructification : ceramidia, contain- ing a tuft of pear-shaped spores. Tetra&pores unknown. — Name, in honour of M. Bonnemaison, a French naturalist. 1. B. asparagoides, Woodw. ; frond compressed or sub- terete ; ceramidia stalked, opposite the cilia. Grev. Alg. Brit. p. 106, t. 13 ; Hook. Br. Fl. ii. p. 295 ; Harv. Phyc. Brit. t. li. Fucus asparagoides, E. Bot. t. 571. — ft. teres ; frond capillary, terete, cilia very long. On rocks near low-water mark, and at a greater depth. Annual. Sum- mer. |3. at Wicklow, and in Kingstown Harbour, Dublin. — Frond 4 — 12 inches long, compressed or nearly cylindrical, varying in breadth from a capillary fineness to nearly a line, excessively branched ; branches disti- chous, alternate, simple, or bearing a second series, gradually shorter up- wards, set throughout at short distances with subulate, distichous ramuli, I or 2 lines long and extremely slender. Capsules ovate, with a short stalk, placed opposite to the cilia, containing a tuft of pear-shaped spores. Fre- quently the capsules are abortive, and then a minute process occupies their place. In a specimen communicated by Mrs. Wyatt, the place of capsules is occupied by a tuft of ramuli, which do not, however, produce telraspores, but occasionally one of them, thicker than the rest, bears a capsule. Colour, a fine transparent crimson, darker in those from the west of Ireland, and in them becoming darker in drying, while in those from the east of Ireland and south of England the colour fades considerably in drying. Substance soft and flaccid. II. LAURENCIA. Lamour. [Plate 12, C.] Frond cylindrical or compressed, linear, pinnately branched, the apices obtuse ; structure cellular, solid. Fructification of two kinds, on distinct individuals; 1, ceramidia, contain- ing a tuft of pear-shaped spores ; 2, triparted tetraspores, imbedded in the ramuli. — Name, in honour of M. de la Lau- rencie, a French naturalist. H 98 LAURENCIA. 1. L. pinnatifida, Gm. ; frond compressed, cartilaginous, bi-tripinnatifid, divisions alternate, the ultimate ones obtuse, simple or lobed. Grev. Alg. Brit. p. 108, t. 14 ; Hook. Br. Fl. ii. p- 296; Wyatt, Alg. Damn. No. 113; Harv. Phyc. Brit. t. Iv. Fucus pinnatifidus, E. Bot. t. 1202.— 0. Os- munda; frond flat, generally undivided, ramuli short and multifid. Hook. 1. c. — y. tenuissima ; frond flat, ramuli very thin and much branched, the branches divaricated. Hook. I. c. On rocks, between tide-marks. Annual. June to September, o. and /8. very common : y. Devon and Cornwall, Mrs. Griffiths. — Fronds tufted, 1 — 12 inches high, compressed or subcylindrical, from half a line to 2 lines in breadth, alternately branched, the branches pinnatifid or bipinnatifid. Substance cartilaginous. Colour varying from a yellowish green to a dull purple or brownish red. Capsules broadly ovate, placed on the smaller branches ; tetraspores imbedded in the ramuli. An extremely variable plant in size and general appearance. The taste is often hot and biting, whence it has obtained the name of Pepper-dulse in Scotland. 2. L. caspitosa, Lamour. ; frond cylindrical or sub-com- pressed, narrow, repeatedly pinnate, pyramidal ; main branches often opposite, erecto-patent ; ramuli irregularly scattered, distichous or spreading on all sides, often crowded, erect, slightly tapering to the base, truncate. Mont, in PL Canar. p. 154; Harv. Phyc. Brit. t. cclxxxvi. L. hybrida, Lenorm. L. pinnatifida, y. angusta, Hook. Br. Fl. ; Wyatt, Alg. Damn. No. 162. On stones, &c., within tide-marks. Annual. Summer. Common. — Fronds 2 — 8 inches high, as thick as small twine, cylindrical or the main divisions slightly compressed, somewhat bare below, much branched above, with a pyramidal outline. Branches once or twice pinnate, erect or erecto- patent, irregularly set. Ramuli very irregular, often much crowded, sim- ple or multifid, terete, tapering to the base and truncate. Colour either a very dark lurid purple, or (under the effects of sunlight) greenish yellow. Almost intermediate between the preceding and following; more cylin- drical and narrower than L. pinna.tifi.da ; and very different in colour and in general habit from L. obtusa. 3. L. obtusa, Huds. ; frond cylindrical, filiform, twice or thrice pinnate ; ramuli mostly opposite, short, patent, wedge- shaped, obtuse. Grev. Ala. Brit. p. Ill ; Hook. Br. Fl. ii. p. 296; Wyatt, Alg. Damn. No. 21 ; Harv. Phyc. Brit. t. cxlviii. Fucus obtusus, E. Bot.t. 1201. On the larger Algae. Annual. Summer and autumn. Shores of Eng- land and Ireland, frequent. Bare ill Scotland. — Root somewhat fibrous. Fronds generally tufted, 3 — 6 inches long, about half a line in diameter, cylindrical, filiform, repeatedly branched in a pinnate manner, the branches and ramuli mostly opposite, the latter 1 or 2 lines long, obtuse or truncate, somewhat narrowed at base, or nearly cylindrical. Substance tender and CHRYSYMENIA. flaccid, soon decomposing. Colour a fine but .fugitive pink, becoming yellowish and whitish in decay. Ceramidia ovate, on the smaller branches ; granules ternate, immersed in the ramuli. 4. L. dasyphylla, Woodw. ; frond filiform, terete, irregu- larly branched ; ramuli short, club-shaped, obtuse, very much attenuate at base. Grev. Alg. Brit. p. 112; Hook. Br. FL ii. p. 296; Wyatt, Alg. Danm. No. 71; Harv. Phyc. Brit. t. clii. Fucus dasyphyllus, E. Bot. t. 847. On rocks or stones between tide-marks. Annual. Summer. Frequent on the shores of England and Ireland. — Root fibrous. Fronds 4 — 12 inches high, cylindrical, half a line in diameter ; stem generally undivided, set with more or less frequent opposite or alternate branches, the lower ones being longest, and frequently bearing a second series ; all having numerous, linear club-shaped, obtuse ramuli, 1 or 2 lines in length, and very much attenuate at base, resembling the leaves of a Sedum : the whole frond marked, at short distances, with more or less distinct transverse striae. Substance somewhat gelatinous, quickly decomposing. Colour a pale fugitive pink, or yellowish. Ceramidia ovate, on the lesser branches : granules ternate in the ramuli. Readily distinguished from the preceding by the ramuli tapering towards the base, and from the following by their being obtuse. 5. L. tenuissima, Good, and Woodw. ; frond filiform, terete, irregularly branched ; ramuli very slender, tapering to the base and apex. Grev. Alg. Brit. p. 113; Hook. Br. FL ii. p. 296; Wyatt, Alg. Danm. No. 22; Harv. Phyc. Brit. t. cxcviii. Fucus tenuissirnus, E. Bot. t. 1882. Between tide-marks, on rocks and other Algae ; very rare. Annual. Summer and autumn. Weymouth, Goodenough and Woodward. Isle of Wight, Rev. G. R. Leathes. Torquay, Mrs. Griffiths. Cornwall, E. Bot. Ballycotton, coast of Cork, Miss Ball. — Root fibrous. Fronds tufted, 6 — 8 inches long, half a line in diameter, cylindrical, much branched in an irre- gularly pinnate manner; the main stem generally undivided, having nume- rous, alternate, spreading branches, of unequal length, some of the longest bearing a second series; and all set, at the distance of one or two lines, with slender, bristle-like ramuli, 1—4 lines long, much attenuated at their insertion, and more or less tapering towards the point. Substance very tender, between gelatinous and cartilaginous. Colour a pale purplish or pinky red, fugitive, and becoming yellowish. Ceramidia ovate, borne by the ramuli, in which also the tetraspores are imbedded. III. CHRYSYMENIA. J. Ag. [Plate 13, A.] Frond tubular, continuous (not constricted or jointed), filled with a watery juice, and traversed by a few longitudinal filaments; its. walls composed of several rows of cells, the innermost of which are distended and much elongated, the outer gradually smaller, and the superficial ones very minute. Fructification : 1, ceramidia, containing a very dense tuft of H 2 100 CHYLOCLADIA. angular spores ; 2, triparted tetraspores, immersed in the ra- mu]j. — Name, from xfursos, golden, and i/K»v, a membrane; because the species assume golden tints if steeped for some time in fresh water. 1. C. clavellosa, Turn. ; frond gelatinous, much branched in a pinnate manner, mostly distichous ; ultimate ramuli lan- ceolate, distichous, or quadrifarious, attenuated at base ; ce- ramidia conical. Grev. Alg. Brit. p. 115 ; Hook. Br. FL ii. p. 297 ; Wyatl, Alg. Damn. No. 23 ; Harv. Plnjc. Brit. t. cxiv. Fucus clavellosus, E. Boi. t. 1283. — &. sedifolius ; ramuli between oblong and oval, crowded, undivided. Turn. On stones, between tide-marks. Annual. May to September. Various stations on the coasts of England, Scotland and Ireland, but nowhere very common. /3. at Lossiemouth, Mr. Brodie. — Fronds tufted or solitary, 3 — 12 inches high, varying from a quarter of a line to more than a line in diameter, gradually widening from the base to the middle, and thence di- minishing to the apex, much branched, repeatedly but irregularly pinnate, the branches patent, opposite or alternate, bearing one or more series of linear-lanceolate ramuli, 1 — 4 lines in length, and closely set; they, as well as the branches, usually distichous, but sometimes springing from all sides of the frond. Ceramidia conical, with a pore, containing a tuft of angular spores ; tetraspores imbedded in the ramuli. Substance flaccid and slip- pery, closely adhering to paper. Colour a brilliant pink. 2. C. Orcadensis, Harv. ; frond distichous, pinnate, the main stem and the pinnae elliptic-oblong, compressed ; pinnae opposite. At Skaill, Orkney, Miss Watt. The specimens yet seen of this supposed species are insufficient to establish its characters fully, but I am unwilling to omit altogether the recording of so remarkable a plant. My specimen, for which I am indebted to the Rev. J. H. Pollexfen, is evidently in a very young state. It is about an inch high ; each frond elliptic oblong, fully a quarter of an inch broad, bearing three or four distant pairs of pinnae, of similar form, but smaller dimensions. The colour is a clear pinky red. The parts of the frond are proportionally very much broader than in any state of C. clavellosa which I have seen ; but in the absence of full-grown specimens I can form no judgment as to the validity of the species. IV. CHYLOCLADIA. Grev. [Plate 13, B.] Frond (at least the branches) tubular, constricted at regu- lar intervals, and divided, by internal diaphragms, into cham- bers, filled with a watery juice and traversed by a few longitudinal filaments; periphery composed of small polygo- nal cells. Fructification: 1, spherical, ovate or conical ceramidia, containing a tuft of wedge-shaped spores ; 2, tri- CHYLOCLAJIA. 101 partite tetraspores, immersed in the smaller branches and ramuli. — Name x>vho{, juice, and xxafoj, a branch. 1. C. ovalis, Huds. ; frond filiform, irregularly dichotomous, naked below, above beset with elliptical, simple (rarely elon- gated and constricted) ramuli, tapering at the base; capsules spherical. Grev. Alg. Brit. p. 116, t. 14; Hook. Br. Fl. \\. p. 297 ; Wyatl, Alg. Danm. No. 114 ; Harv. Phyc. Brit. t. cxviii. Fucus ovalis, E. Bot. t. 711. In the sea, on rocks and Algae. Annual. June to August. Frequent on the shores of England and Ireland. Little Isles of Jura, Papa Westra, Lightfoot. — Fronds tufted, 2 — 10 inches high, cylindrical, from half a line to a line in diameter, irregularly and somewhat distantly dicho- tomous, naked below ; branches above more or less densely set with ellipti- cal or lanceolate, clustered or scattered ramuli, 1 — 4 lines long, half a line to a line in diameter, much attenuated at base, either obtuse or some- what tapering at apex, and either simple, or contracted at intervals as if jointed. Substance cartilaginous in the stem ; tender in the ramuli, which are filled with a laxly gelatinous fluid. Capsules globose, with a pellucid limbus sessile on the ramuli ; tetraspores imbedded in the ramuli. 2. C. kaliformis, Good, and Woodw. ; frond sub-gelati- nous, tubular, distantly constricted as if jointed, repeatedly pinnate; branches whorled at the constrictions with chain- like ramuli; capsules spherical, with a pellucid border. Grev. Alg. Brit. p. 117; Hook. Br. Fl. ii. p. 298; Wyatt, Alg. Danm. No. 24 ; Harv. Phyc. Brit. t. cxlv. Fucus kaliformis, E. Bot. t. 640. In the sea, on rocks and other Alga?. Annual. June to September. Frequent on the coasts of England, Scotland and Ireland. — Fronds tufted, 4 — 12 or even 18 inches long, 1 or 2 lines in diameter; stem undivided, attenuated at each extremity, and contracted at intervals of half an inch or more. From the contractions spring long, simple, primary branches, simi- lar to the stem, but more slender and more regularly contracted, opposite or in whorls, patent, and bearing at their contractions one or more series of lesser branches and ramuli, all of which taper at each end, and are more or less distinctly contracted, the contractions of the ramuli being very close together. Substance tender and gelatinous. Colour a fugitive pink or purplish red. Capsules spherical, placed on the young branches ; tetraspores in the ramuli. 3. C. rejiexa,) Chauv. ; frond membranaceous, purple ; lower branches cylindrical, slender, arched, attaching them- selves by short rooting processes ; secondary branches simple, mostly secund, moniliform, spindle-shaped ; ramuli few, scat- tered, patent or recurved. Harv. Phyc. Brit. t. xlii. On rocks, near low-water mark. Annual. Summer. Very rare. Haging- ton, near Ilfracombe, Miss Amelia Griffiths. — Frond 2—3 inches high, branching irregularly from the base ; the lower branches cylindrical, form. 102 CHYLOCLADIA. ing successive arcs, attached at intervals to other Algae by short rootlets tipped with disks. Secondary branches spring from the arched ones, either two or three from one point, or else they are solitary and secund : these are regularly constricted into articulations about once and a half as long as broad. * Nearly related to C. kaliformis, from which it is chiefly distin- guished by its creeping habit and small size. The Irish station given in Phyc. Brit, is incorrect. 4. C. parvula. Ag. ; frond sub-gelatinous, slender, branched in a straggling, sub-dichotomous manner ; branches con- stricted at intervals of equal length and breadth ; capsules ovate. Grev. Alg. Brit. p. 119; Hook. Br. FL ii. p. 298 ; Wyatt, Alg. Danm. No. 72 ; Harv. Phyc. Brit. t. ccx. Chon- dria parvula, Grev. Crypt, t. 346. Parasitical on the smaller Algae. Annual. Summer and autumn. Not uncommon. — Fronds rising from a mass of fibres, densely tufted, 2 or 3 inches long, half a line in diameter, excessively branched and entangled ; branches irregular, opposite or alternate, of various lengths, with or without scattered ramuli, which are slightly attenuated at base ; the tips obtuse ; the whole frond marked, at distances of nearly equal length and breadth, with external constrictions, and furnished with internal septa. Capsules ovate, borne on the smaller branches, and containing a spherical mass of ovate seeds ; tetraspores in the articulations of the branches. Substance soft and somewhat gelatinous. Colour a fine, but fugitive, pinky red. Well distinguished from C. kaliformis by the ramification, the uniformly short articulations, and the shape of the conceptacles. 5. C. articulata, Huds. ; frond tubular, gelatinoso-mem- branaceous, strongly constricted throughout, as if jointed, much branched in a fasciculato-dichotomous manner ; cap- sules obtusely conical. Grev. Alg. Brit. p. 120; Hook. Br. Fl. ii. p. 298 ; Wyatt, Alg. Damn. No. 73 ; Harv. Phyc. Brit. t. cclxxxiii. Fucus articulatus, E. Bot. t. 1574. Between tide-marks, on rocks and the larger Algae. Annual. Summer. Fronds springing from a mass of fibres, tufted, I — 6, or occasionally 12 inches long, excessively branched and bushy, constricted at regular inter- vals of 2 — 4 lines, irregularly divided ; main stem somewhat dichotomous, bearing at its constrictions whorls of branches, which again divide dichoto- mously, and bear from their joints opposite or whorled, lanceolate ramuli. The tips of the branches are somewhat fastigiate and the plant has a rounded outline. Capsules conical ; tetraspores in the joints of the ramuli. Colour a fine pinky red, less fugitive than in others of the genus. Substance membranaceous, filled with watery gelatine. CORALLINACE.E. 103 ORDER IX. CORALLINACE^E. Corallineao, Lamour. Cor. Class, p. 244 ; Dne. Class, p. 63; Endl. 3d Suppl. p. 48; Harv. Ner. Austr. ined.; Lindl. Veg. King. p. 25. Corallineae and Spongiteae, Kuiz. Phyc. Gen. pp. 387, 385. Corallinidae and Nulliporidae, Johnst. Brit. Lith. p. 205, &c. DIAGNOSIS. — Rigid, articulated or crustaceous, mostly cal- careous sea-weeds, purple when recent, fading on exposure to milk-white, composed of closely packed, elongated cells or filaments, in which carbonate of lime is deposited in an organized form. Tetraspores tufted, contained in ovate or spherical conceptacles (ceramidia) furnished with a terminal pore. NATURAL CHARACTER. — Root, where this organ is mani- fested, an expanded, crustaceous disk, often spreading widely. Frond almost always calcareous, effervescing strongly when thrown into acids, rarely destitute of lime, very variable in aspect and habit. The lowest forms of the order are simple incrustations, spreading, like the crustaceous lichens, over the surface of rocks or the fronds of the larger Algae. In the smaller of these the crust is a mere film, as thin as paper, ge- nerally circular, and extending by means of small additions to the circumference ; so that the frond becomes marked, as it advances, with concentric circles. In the larger, the crust is thick and. stony, rising here and there into prominences, and sinking in depressions. Still further advance manifests itself by the crust assuming a branching habit; at first, pa- pillae rise from the surface ; these thicken, and widen and lengthen, and at length throw out branches, till a shrubby frond, of stony hardness, but extremely brittle, is formed. All these changes in character take place within the limits of a single genus, Melobesia. Nearly related to this (and by many botanists considered identical) is Mastophora, a genus in which the frond is expanded into leafy lobes, usually fan- shaped, sessile or stalked, but not adnate to rocks, of a flex- ible substance, containing a smaller portion of carbonate of lime than in the former group. Some of these have the habit of Padina, but differs from that genus in being of a red co- lour. They are the most perfectly-organized of the leafy or frondose Corallines (Nulliporeee). — The articulated, or true 104 COHALLINACE/E. Corallines, are filiform, either pinnated, or dichotomous, the branches formed of strings of calcareous articulations, trun- cated at the upper extremity and rounded at the lower, each articulation connected with that above and below it by a flexible joint, composed of cellular tissue, destitute of car- bonate of lime. This joint in our British species is scarcely obvious till after maceration, but in many exotic species (of Amphiroa] it is so long as to interrupt the continuity of the articulations, and is either naked, or coaled with wart-like, calcareous tubercles. The form of the articulations varies extremely, and often in the same species, or even in the same specimen, so that the determination of these plants is some- times difficult. In many the articulations are cylindrical ; in others oval and compressed ; in some flat and irregularly shap- ed ; but in the greater number they are heart-shaped or wedge- shaped, with the upper angles frequently prolonged with horns. The fructification consists of hollow, external or immersed conceptacles, containing a tuft of oblong spores, divided at maturity, by three horizontal fissures, into four parts. They are therefore tetraspores ; precisely similar to those of Ploca- mium, Hypnea, &c. The nature of the conceptacle varies, even in the same species. Thus, in Corallina, it is normally formed by the metamorphosis of the terminal articulation of the branches, which swells at the sides and becomes pierced at the apex. But in C. squamata, and even in C. officinalis, other articulations frequently bear numerous small, hemi- spherical conceptacles on their sides; and sometimes the whole surface is warted with such ; and these irregular organs are equally furnished with tetraspores as the normal ones. These latter conceptacles, which are irregular in Corallina, are the normal fruit of Amphiroa, a genus chiefly from the Southern Ocean. In Jania the conceptacle is similar to that of Corallina, except that it generally bears a pair of ramuli (resembling the antennae of an insect) from its upper angles. The Corallines are found in all parts of the Ocean, but are much more numerous in warm than in cold countries, and some of the species of the tropical and sub-tropical ocean are among the most beautiful of marine vegetables. Until re- cently the plants of this order were, with other calcareous Algae, confounded with the zoophytes, or polypiferous corals. They are, however, undoubtedly, of vegetable nature ; and when the lime which they contain is removed by acid, the vegetable framework, concealed beneath it, is found to be of a similar structure to that of other Rhodosperms, to which CORALLINACES. 105 group of Algae they are further allied by their colour and the nature of their spores. The Order consists of two, or, if Lithocystis be rightly placed in it, of three sub-orders, as follows : — SYNOPSIS OF THE BRITISH GENERA. Suborder 1. CORALLINES. Frond filiform, articulated. I. CORALLINA. (Frond pinnated). Ceramidia terminal, simple. [Plate 13, C.] II. JANIA. (Frond dichotomous). Ceramidia tipped with two horn-like ramuli. [Plate 13, D.J Suborder 2. NULLIPORES. Frond crustaceous or foliaceous, opake, not articulated. III. MELOBESIA. Frond stony, forming either a crusta- ceous expansion, or a foliaceous, or shrub-like body. [Plate 14, A.] IV. HILDENBRANDTIA. Frond cartilaginous, not stony, forming a crustaceous expansion. [Plate 14, C.] Suborder 3 ? LYTHOCYSTES. Frond plane, hyaline, com- posed of cells radiating from a centre. Fructification unknown. V. LYTHOCYSTIS. (A minute parasite}. [Plate 14, B.] Suborder 1. CORALLINES. Frond filiform, articulated. I. CORALLINA. Linn. [Plate 13, C.] Frond filiform, articulated, branched (mostly pinnate), coated with a calcareous deposit. Fructification, turbinate or obovate, mostly terminal ceramidia, pierced at the apex by a minute pore, and containing a tuft of erect, pyriform, or club-shaped, transversely parted tetraspores. Name, from Coralium, coral, which these plants resemble in having a stony substance. 106 CORALLINA. 1. C. officinalis, Liun.; decompound-pinnate; lower arti- culations cylindrical, twice as long as broad ; upper slightly obconical, round-edged, their upper angles blunt ; ultimate ramuli cylindrical, obtuse. Johnst. Brit. Lith. p. 216; Harv. Phyc. Brit. t. ccxxii. On rocks, &c. between tide-marks, extending from the limits of high, to the extremity of low-water mark. Perennial. Winter and spring. Very abundant on the British shores. — Root a widely-expanded, red crust. Fronds 2 — 6 inches high, tufted, much branched, bi-tripinnate ; but vary- ing greatly in luxuriance according to the depth at which it grows. The fructification varies in different specimens ; normally the ceramidia are urn-shaped, formed by the transformation of the terminal articulation of the ramuli ; but sometimes the other articulations produce lateral ovate capsules, sometimes two, sometimes more springing from the same articu- lation, and occasionally the whole frond becomes densely warted with this irregular fruit. 2. C. elongata, Ell. and Sol. ; " the lateral shoots of the branches slender and subulate, with long, cylindrical articu- lations." Johnst. Lith. p. 221. Coast of Cornwall, Ellis. Jersey, Mr. Hassall. " Coralline attached by a crustaceous base, rising to the height of 3 or 4 inches, very bushy, distinctly jointed, slender, the ultimate branchlets almost hair-like : arti- culations of the stem not much longer than their own diameter, somewhat compressed and wedge-shaped, the shoulders often produced into a spinule ; articulations of the setiform pinnules cylindrical, from two to six times their diameter in length, often terminated with a graniferous tubercle, which frequently becomes axillary from little setaceous branches shooting up from each side." Johnst. 1. c. I am not acquainted with this species. 3. C. squamata, Park.; decompound pinnate; lower arti- culations cylindrical, scarcely longer than their breadth ; upper obconical or obcordate, compressed, two-edged, their upper angles sharp and prominent ; ultimate ramuli very slender, acute. Johnst. Brit. Lith. p. 222; Harv. Phyc. Brit. t. cci. On rocks, near low-water mark. Perennial. Summer. South of Eng- land, Jersey, and South and West of Ireland. — This has the habit of C. qfficinalis, but differs in the form of the upper articulations, which are here much compressed, with the angles sharp and prominent. Two abnormal states of fruit are figured in Phyc. Brit., one of which resembles the normal fructification of Jania (section Haliptilon) ; the other that of Amphiroa. Such irregularities show how little dependance can be placed on characters derived from fructification in this family of plants : and I fear characters of ramification are equally treacherous. JANIA. — MELOBESIA. 107 II. JANIA. Lamour. [Plate 13, D.] Frond filiform, articulated, dichotomous, branched, coated with a calcareous deposit. Fructification, urn-shaped cera- midia, formed of the axillary articulation of the uppermost branches (mostly two-horned), pierced at the apex by a minute pore, and containing a tuft of erect, pyiiform, trans- versely parted tetraspores. Named from Janira, one of the Nereides. 1. J. rubens, Linn. ; articulations of the principal branches and ramuli cylindrical, about four times as long as broad. Harv. Phyc. Brit. t. cclii. On the smaller Algae between tide-marks. Perennial. Summer. On all parts of the British coast. — From half an inch to 1 — 2 inches high, densely tufted, dichotomous, many times forked, fastigiate, branches either erect or spreading, gradually tapering upwards. Articulations cylindrical in all parts of the frond, without prominent angles ; those near the base very short, the upper ones gradually longer. Ceramidia subterminal, urn- shaped, with long horns, formed of from two to four articulations. Colour a pale red, with a purplish shade when quite fresh. A common plant on the shores of Europe, and perhaps throughout the temperate Atlantic. 2. J. corniculata, Linn. ; articulations of the principal di- visions obconical, compressed, their upper angles sharp and prominent ; those of the uppermost ramuli cylindrical, fili- form. Harv. Phyc. Brit. t. ccxxxiv. On smaller Algae between tide-marks. Southern shores of England and Ireland, Jersey. — Forms small dense tufts, 1 — 2 inches high, composed of slender, dichotoraous fronds ; branches fastigiate. Articulations of the principal branches 2 — 3 times as long as broad, tapering to the base, en- larged laterally upwards, compressed, their upper angles prolonged into a conical horn. Colour pale red. Known from the last by the different form of the articulations of the principal branches. Suborder 2. NULLIPORE.E. Frond crustaceous or folia- ceous, opake, not articulated. III. MELOBESIA. Lamour. [Plate 14, A.] Frond attached or free, either flattened, orbicular, sinuated or irregularly lobed, or cylindrical and branched (never arti- culated), coated with a calcareous deposit. Fructification: conical, sessile ceramidia, scattered over the surface of the 108 MELOBESIA. frond, and containing a tuft of transversely parted, oblong tetraspores. — Named from one of the sea-nymphs of Hesiod. * Frond thick, solid, stony, either shrub-like or encrusting. 1. M. polymorpha, Linn.; frond attached to rocks, thick, stony, encrusting, or rising into short, clumsy branches, which are seldom much divided, and often merely rudimentary. On rocks, stones, shells, &c. between tide-marks. Perennial. Common. — I suppose that most of the thick, difform, nulliporous crusts found between tide-marks would be referable to this species. Much remains to be done in working out the species of this genus. I do not pretend to understand them fully, not having sufficiently attended to their variations on the coast, and not possessing a sufficient suite of specimens to enable me to solve their difficulties in the cabinet. 2. M. calcarea, Ell. and Sol. ; " is extremely white, solid and dichotomously branched ; the little branches often unite together and become smaller at the ends." Ellis and Sol. p. 129, t. 23, /. 13 : Johnst. Brit. Lith. p. 240, t. 24, /. 4, 5. M.fragilis, M'Calla? Coasts of South of England and West of Scotland and Ireland. I have not seen any authentic specimen, but Ellis's figure is a faithful representa- tion of the M.fragilis of M'Calla, which abounds on most of our coasts in 4 — 10 fathoms water. When recent it is a deep blood red, soon passing into brick-dust colour, and finally to a snowy whiteness. The branches are slender, divaricating, spreading in all directions, anastomosing below ; free above and tapering to a blunt point. The ultimate ramuli are either simple or forked. On many parts of the coast this plant forms vast beds, extending for miles, in submarine strata ; and is advantageously used as a manure on soils requiring the addition of lime. Here should also be men- tioned M. compressa of M'Calla, which I have not yet had an opportunity of examining in a recent state. It differs from M. calcarea in having a compressed frond, with flat branches broader towards the tips, and is pro- bably as good a species as any other of these variable forms. 3. M. fasciculata, Lam. ; frond unattached, roundish or lobed, stony, much branched, fastigiate; branches solid, thick, crowded together, cylindrical or compressed ; apices truncate, broad, somewhat concave. Johnst. Brit. Lith. p. 240 ; Harv. Phyc. Brit. t. Ixxiv. Lying at the sandy bottom of the sea in 4 — 5 fathoms water. Found on several parts of the coast. — Fronds 1 — 3 inches in diameter, roundish or irregularly lobed, composed of a stony central mass, from which issue seve- ral short lumpy branches. Colour a dark lurid purple, soon fading in the air. ** Frond thin, foliated, free, or partially attached to rocks. 4. M. agariciformit, Pall.; frond unattached, globular, MELOBESIA. 109 hollow ; foliations delicate, papyro-crustaceous, dense, erect, much lobed and sinuated, fastigiate; margin thin, entire. Johnst. Brit. Lith. p. 241 ; Harv. Phyc. Brit. t. Ixxiii. Lying on the sandy bottom of quiet bays, in 2 — 3 fathoms water. Bound- stone Bay, Cuunemara.— This forms globular masses 4 — 8 inches in dia- meter, hollow, from the central portion continually rotting away as the exterior foliations extend. The whole is composed of innumerable vertical leafy plates closely packed together, and variously twisted. It is of a pale flesh-colour when fresh. 5. M. lichenoides, Borl. ; frond attached to rocks, free at the margins, foliaceous, lichenoid, variously lobed ; foliations spreading, often imbricated ; ceramidia large, conical, promi- nent. On rocks and in tide-pools, near low -water mark. Not uncommon. Pe- rennial ? — Variable in habit, resembling one of the leafy Lichens, such as a Peltidia, spreading over rocks, or somewhat erect, the marginal lobes generally free. Colour pale. Some varieties of this plant closely resemble small specimens of M. ayariciformis, and would lead us to infer that the difference in habit was caused by the different depths at which these plants vegetate. *** FrQnd minute, thin, parasitic on various Alga, &c. 6. M. membranacea, Lamour. ; minute, dot-like, very thin, pale purple, circular, at length confluent, attached to other Algae; ceramidia one or two, depressed. Common on the leaves of Zostera, the fronds of Chondrus crispus, &c. Annual. Summer.— From half a line to a line in diameter, very thin, and almost membranous, dotting over the plant on which it grows. It very frequently is found in fruit, having two or more depressed ceramidia. 7. M. farinosa, Lamour. ; minute, irregular in outline, rather thin, pallid, with two or three prominent ceramidia. On various Algae. — Rather larger and thicker than the preceding, with more prominent fruit, but to me it appears merely a stronger-grown variety. I depend, for the name, on a specimen from the Mediterranean, communi- cated by M. Lenormand. 8. M. verrucata, Lamour. ; thin, expanded, irregularly lobed, pallid, dotted over with innumerable small, pimply ceramidia. On Phyllophora rubens, &c. — Looks like a still more advanced state of M . membranacea. 9. M.pustulata, Lamour. ; thick, dull purple or green, ob- long or lobed, incrusting, smooth j ceramidia numerous, large, rather prominent, conical. On Phyllophora rubens, Chondrus crispus, &c. — This is the largest and HO HILDENBRANDTIA. most developed of this parasitic section of the genus, and perhaps, without much violence, the three preceding species might be considered as merely younger and imperfect forms. Dr. Johnston goes much further, and re- fers the whole to Corallina ojficinalis. This plant, says he, " appears first in the guise of a thin, circular, calcareous patch of a purplish colour, and in this state is common on almost every object that grows between tide- marks. When developing on the leaves of Zostera, or in other unfavour- able sites, these patches are usually pulverulent and ill-coloured, green or white, and never become large ; but in suitable situations, they continue enlarging in concentric circles, each marked with a pale zone, until they ultimately cover a space of several inches in diameter. The resemblance which, in this condition, the crust has to some crustaceous fungi, more es- pecially to Polyporus versicolor, is remarkably exact, and neither is it less variable than the fungus in its growth, the variations depending on the na- ture of the site from which it grows. If this is smooth and even, the folia- ceous coralline is entirely adnate and also even, but if the surface of the site is uneven or knobbed, the coralline assumes the same character. If it grows from the edge of a rock, or on the frond of a narrow sea-weed, or from the branch of the perfect coralline, the basal lamina spread beyond in over- lapping imbrications of considerable neatness and beauty : they are semi- circular, wavy, either smooth or studded with scattered granules, and these granules [ceramidia] may be either solid or perforated on the top. Such states of the coralline have been described as Millepora lichenoides ; while its earlier states constitute Lamouroux's various species of Melobesia." — Johnst. Brit. Lith. p. 220. IV. HILDENBRANDTIA. Zanard. [Plate 14, C.j Frond cartilagineo-raembranaceous (not stony], crusta- ceous, suborbicular, adhering by its lower surface ; composed of very slender, closely packed, vertical filaments. Concep- tacles immersed in the frond, orbicular, depressed, pierced by a hole, and containing tetraspores and paraphyses at the base of the cavity. 1. H. rubra, Meneg. ; Mem. Riun. Nat. Padov. 1841, p. 10; Harv. Phyc. Brit. t. ccl. Rhododermis Drummondii, Harv. in Ann. Nat. Hist. vol. xiv. p. 27, t. 2. On smooth stones and pebbles between tide-marks, and in deep water. Common. — Forms a thin, membranous crust, at first orbicular, and spread- ing concentrically, at last irregular in form, following the sinuosities of any body to which it may be attached. A small portion, viewed vertically under the microscope, shows minute cells, lying in clear jelly. When in fruit the surface is pitted with disk-like depressions, pierced by a hole which communicates with a chamber in which the spores lie. Colour va- riable ; now a bright, now a dull red. Sub-order 3 ? LITHOCYSTE.E. Frond plane, hyaline, com- posed, of cells radiating from a centre. Fructification un- known. LITHOCYSTIS. Ill V. LITHOCYSTIS. Allm. [Plate 14, B.] " Plant calcareous, consisting of a single plane of cellules, which are disposed in radiating, dichotomous series, forming an appressed, flabelliform frond." — Allm. Name, from x<0oj, a. stone, and xvn?, a bladder; because the cells have stony coats. 1. L. Allmanni, Harv. Phyc. Brit. t. clxvi. Parasitical on Chrysymenia clavellosa, from an oyster bed, Malahide, Dublin, Professor Allman. — Forming minute, dot-like patches of a whitish colour on the fronds of the Chrysymenia. Each dot consists of one or se- veral fan-shaped fronds, composed of quadrate cells, disposed in dichoto- mous series. The plant is brittle, colourless, and effervesces in acid. ORDER X. DELESSERTACE^. Delesserieae, J. Ag. Alg. Medit. p. 116; Endl. 3rd Suppl. p. 52 ; Lindl. Veg. King. p. 25. Gasterocarpeae (partim), Due. Class, p. 65. Thamnophoreae (partim), Due. 1. c. p. 63. Delesserieae and Plocameae, Kutz. Phyc. Gen. pp. 44, 449. DIAGNOSIS. — Rosy or purplish red, or blood-red sea-weeds, with a leafy, or rarely filiform, areolated, inarticulate frond, composed of polygonal cells. Leaves delicately membrana- ceous. Fructification double ; 1, Conceptacles (coccidia] external or half immersed, hemispherical, usually imperfo- rate, containing, beneath a membranous pericarp, a tuft of dichotomous filaments, whose articulations are finally changed into spores. 2, Tetraspores in distinctly defined sort, either scattered through the frond or placed in proper fruit-leaflets or sporophylla. NATURAL CHARACTER. — Root usually a conical disk, in some Plocamia and in Hymenena much branched, composed of many clasping fibres ; and occasionally the frond is at- tached at intervals by disk-like roots, which issue from the under side of the midribs, or from the tips of the leaves. Frond rarely (Plocamium) linear, very narrow or filiform, and much branched ; usually leafy, or expanded : in many cases forming distinct leaves, of definite shape, with costa and lateral nerves, in others consisting of leaf-like membranes BELESSEMAtJEB. of irregular form, without distinct costa, and either homoge- neous, or traversed by branching, obscure and vanishing nerves. The distinction of the frond into stem and leaves, although in some cases, as in Delesseria sanguined, very ob- vious, is nowhere, to my knowledge, absolute ; the stems having, at an early period of growth, been in all cases leaves, and having lost their leafy character by the destruction of the lateral membrane, which never grows again. The costa, continuing to vegetate, throws out from its sides new leafy fronds, and thus the branching often becomes very irregular. This power of the costa to originate new fronds from any part equally exists in such branching plants as Del. alata, which is often converted from a flat and perfectly distichous forked leaf into a dense, bushy tuft, composed of innume- rable similar leaves, springing, without order, each from the midrib of an older leaf. In Del. hypoglossum and D. rusci- folia this proliferous habit is shown in perfection. In these species each frondlet is perfectly simple at all ages, and composition can only take place by new frondlets springing from the midribs of the old. Other species, as D. alata and D. sinuosa, have a double mode of enlargement ; normally by division of the frond, and abnormally by proliferous develop- ment. The cells of which the frond is composed are rarely elongate. In most cases they are twelve-sided, about as long as broad, and heaped together without much order ; but in some they are cubical, and disposed in regular rows, vertical with the surface when the frond is thick. But in no case do they cohere strongly by their ends, so as to form separable filaments. The surface cells are often, but not always, large and flattened, and thus the frond has an areolated appear- ance under a lens. The coccidia are produced on various parts of the frond, and are either formed by a metamorphosis of a leaf (as in D. sanguined], in which case they are pedi- cellated ; or they originate from the midrib, as is common in Delesseria ; or they are scattered over the membrane, as in Nitophyllum and in Delesseria Lyallii. They are usually hemispherical, prominent on one or other side of the frond indifferently, having a membranous pericarp, usually as thick as the frond from which it is developed, and they contain, on a central, basal placenta a tuft of dichotomous threads, with moniliform articulations, whose apical cells, and sometimes all the cells of the filament, are converted into spores, acquir- ing a dark red colour and dense substance. The tetraspores are commonly triangularly parted, but in Plocamium they are DELESSERIA. 113 transversely zoned. In all cases they form well-defined sort or spots, which either occupy a portion of the surface of the membranous frond, or are confined to spore-leaflets (sporo- phylla], which spring from some part of the frond. This order is chiefly known from the Rhodymeniaceae by the defi- nite arrangement of the tetraspores ; but the plants of the latter family are of a coarser texture, and in many instances have a partially fibro-cellular structure. The Delesseriaceae are not numerous, but they are widely scattered through the temperate and colder latitudes of both hemispheres. Few are tropical, and those of small size. On the shores of northern Europe and of the antarctic lands the finest species occur, some having fronds several feet in length. Where soil and exposure are favourable, some of the British Nitophylta, especially N. punctatum, attain very large di- mensions. Of Plocamium our common species is found in all cool waters, being equally common at the North Cape of Europe and at Cape Horn, and extending in both hemi- spheres to some 34° of the line ; but it is the only one of the genus to which it belongs whose habits are equally pelagic. All the other species, and there are several, are natives of the southern hemisphere, chiefly of the shores of South Africa and New Holland. SYNOPSIS OF THE BRITISH GENERA. I. DELESSERIA. Frond leafy, of definite form, with a percurrent midrib. [Plate 15, A.] II. NITOPHYLLDM. Frond leafy, of indefinite form, with- out a midrib (sometimes traversed by vague, vanishing nerves). [Plate 15, B.] III. PLOCAMIDM. Frond linear, or filiform, compressed, much branched, distichous ; ramuli pectinate, secund. [Plate 15, C.] I. DELESSERIA. Lamour. [Plate 15, A.] Frond rose-red, flat, membranaceous, with a percurrent midrib. Fructification of two kinds, on distinct individuals : 1, hemispherical tubercles (coccidia), mostly on the midrib, 114 DELESSERIA. containing a tuft of filaments, bearing the spores : 2, tetra- spores forming definite spots in the frond, or in distinct leaf- like processes. — Named in honour of M. Benj. Delessert, a distinguished French naturalist and patron of Botany. 1. D. sanguinea, Linn. ; stem cylindrical, cartilaginous, branched, bearing oblong or obovate, transversely veined leaves, entire at the margin ; midrib percurrent, strong ; tu- bercles stalked, attached to the midrib. Grev. Alg. Brit. p. 72 ; Hook. Br. Fl. ii. p. 285 ; Wyatt, Alg. Danm. No. 13 ; Harv. Phyc. Brit. t. cli. Fucus sanguineus, E. Bot. t. 1041. In the sea. Biennial. Fruiting in winter, after the decay of the leaves. Common. — Stem simple or slightly branched, thick, bearing numerous ob- long or broadly obovate, obtuse, penninerved leaves, 2 — 8 inches long, 1 — 6 inches wide, of a splendid pinky-red colour and delicately membranous substance ; the margin waved, but quite entire ; the midrib and lateral veins prominent, the former occasionally giving rise to small proliferous leaves. Such is the summer state. In winter the membranaceous portion of the frond almost entirely decays, leaving little but the stems and mid- ribs, which are then found fringed with fructification ; the tubercles raised on little stalks about a line long; the tetraspores placed in little leafy pro- 2. D. sinuosa, Good. & Wood.; stem elongated, branched, beset with oblong or obovate, deeply sinuate or pinnatifid, toothed, penninerved leaves; nerves opposite. Hook. Br. Fl. ii. p. 285 ; Wyatt, Alg. Danm. No. 62 ; Harv. Phyc. Brit. t. cclix. Fucus sinuosus, E. Bot. t. 822. On the larger Fuci, common. Biennial ? Summer and autumn. Stem in young plants with a decurrent membrane (the remains of the simple leaf of which the plant at first consists) ; in old, naked and somewhat pinnat- edly branched ; the branches or leaves of an oblong or obovate form, deeply sinuate, or in many specimens pinnatifid, each lobe having a sinuous, jag- ged or serrated, sometimes ciliated margin ; furnished with a strong mid- rib, and transverse opposite veins. Colour a fine rose-red, purplish when dry; much duller at all times than that of the preceding. Fructification : ] , tubercles imbedded in the midrib of the leafy lobes -. 2, tetraspores placed in minute, slender processes, fringing the margin, and resembling cilia, formed out of a dissolved portion of the midrib. 3. D. alata, Huds. ; stem excessively branched, some- what dichotomous, linear, winged with membrane without distinct leaves ; branches attenuate ; margin entire. Grev. Alg. Brit. p. 73 ; Hook. Br. Fl. ii. p. 285 ; Wyatt, Alg. Danm. No. 14; Harv. Phyc. Brit. t. ccxlvii. Fucus alatus, E. Bot. t. 1387. On the larger Algae, common. Biennial? Summer. — Frond 3 — 8 inches high, 1 — 4 lines wide, much branched in a dichotomous manner, linear, the membrane decurrent along the branches, its margin quite entire, DELESSERIA. 115 its surface marked, in luxuriant specimens, with evident transverse striae. Colour a deep red. Tubercles spherical, attached to the midrib, generally near the ends of the branches ; tetraspores imbedded in little leafy processes of the midrib, generally at or near the tips ; sometimes in the tips them- selves. 4. D. angustissima, Griff. ; frond merubranaceo-cartilagi- nous, compressed, very narrow, two-edged, much branched ; branches alternate, distichous, of unequal length, much di- vided above, and furnished with numerous forked ramuli ; tubercles imbedded either in the tips of the frond, or in small, axillary ramuli j tetraspores forming soil either in the inflated apices, or in axillary, lanceolate ramuli. Harv. Phyc. Brit, t. Ixxxiii. Del. alata, y. angustissima, Grev. Alg. Brit. p. 74. Gelidium ? rostratum, Griff, in Harv. Man. 1st ed. p. 82. On the stems of Laminaria digitata. Perennial. Winter and Spring. North of Scotland and east coast of England. — Fronds 4 — 8 inches long, not half a line in diameter, nearly cylindrical below, compressed and two- edged above, much branched. Branches distichous, alternate or dichoto- mous, or somewhat pinnate. Colour dark red. Substance cartilaginous. I admit this plant in deference to the opinion of Mrs. Griffiths, who con- siders it permanently distinct from the preceding, by the above characters. To me it appears merely an extreme variety of a variable plant. 5. D. Hypoglossum, Woodw. ; frond much branched in a proliferous manner, composed of linear-lanceolate, midribbed leaves, tapering at each end, the younger series springing from the midribs of the older; tetraspores forming an obloug line at each side of the midrib, near the tips of the leaves. Hook. Br. Fl. u.p. 286; Wyatt, Alg. Danm. No. 63 ; Harv. Phyc. Brit. t. ii.; E. Bot. t. 1396. On rocks and other Algae, not uncommon on the shores of England and Ireland; rare in Scotland. Annual. Summer. — Fronds several from the same base, at first forming a simple, linear-lanceolate leaf, furnished with a distinct midrib, and faintly marked by pellucid transverse veins ; after- wards excessively branched, and forming globose tufts 4 — 6 inches in diameter; the branches or leaves springing from the midrib of those first formed, resembling them in outline, and bearing from their midribs a se- cond and third series. Colour a fine pinky-red, soon given out to fresh water. Tubercles globose, seated on the midrib about the centre of the leaflet ; tetraspores disposed in linear longitudinal lines or sori, at each side of the midrib, often near its end. Some of Miss Hutchins's specimens, gathered at Bantry Bay, are of very large size, the primary leaf being 6 — 8 inches long, and half an inch wide. In the common varieties the leaves are seldom more than two lines, but frequently only a line in breadth. 6. D. ruscifolia, Turn. ; frond branched in a proliferous i 2 H({ NITOPHYLLUM. manner, composed of linear-oblong, obtuse, midribbed leaves, scarcely tapered at base, the younger series springing from the midribs of the older ; tetraspores forming an oblong line at each side of the midrib. Grev. Alg. Brit. p. 76 ; Hook. Br. Ft. ii. p. 286; Wyatt, Alg. Danm. No. 64; Harv. Phyc. Brit. t. xxvi; E. Bot. t. 1297. On rocks and Laminarieee, &c. ; rather rare. Annual. Summer and autumn. Shores of England and Ireland. — Originating, like the last, in a simple leaf, branched in a similar manner, and with a similar fructifica- tion. It differs chiefly in the form of the leaves, which are shorter, boader, obtuse at the apex and not tapering at the base ; but specimens are occa- sionally found presenting intermediate appearances. The colour, too, is generally deeper, the substance rather firmer, and the reticulations smaller than in the last. IT. NITOPHYLLUM. Grev. [Plate 15, B.] Frond membranaceous, reticulated, rose-red (rarely pur- plish), veinless, or furnished with irregular veins towards the base. Fructification : 1, convex tubercles (coccidia) sessile on the frond, containing a tuft of filaments which bear the spores : 2, tetraspores forming distinct, scattered spots. — Name, from nitor, to shine, and (pwxxov, a leaf. The absence of a nerve distinguishes this genus from Delesseria, as do the thinner, more reticulated substance, and distinct spots of tetraspores, from Rhodymenia. 1. N. punctatum, With. ; frond very thin and delicate, destitute of nervures, either regularly dichotomous or cleft into two or three principal segments, whose margins are fringed with dichotomous lobes, the axils rounded; spots of tetraspores large, scattered over the whole frond or confined to its segments. Grev. Ala. Brit. p. 79, t. 12; Hook. Br. Fl. ii. p. 287. Fucus punctatus, E. Bot. t. 1575 ; Harv. Phyc. Brit. t. ccii. cciii. — ft. ocellatum ; frond with a roundish outline, cleft nearly to the base, the segments repeatedly di- chotomous, linear. N. ocellatum, Grev. Hook. Br. Fl. ii. p. 286 ; Wyatt, Alg. Danm. No. 15. Delesseria ocellata, Grev. Crypt, t. 347. Attached to various Algae within and beyond the tidal limit. Annual. Summer. On the coasts of England, Ireland and Scotland, in many places ; the Irish specimens of large size. £. coast of Moray, Mr. Brodie. Torquay and Sidmouth, Mrs. Griffiths. Bantry Bay, Miss Hutchins. — Frond primarily of a broadly wedge-shaped form, afterwards dichotomonsly divided, with rounded axils, the segments preserving their wedge shape, commonly from 4 to 12 inches long and about as broad, but in favourable situations much larger, and in some gigantic specimens gathered by Mr. NITOPHYLLUM. 117 D. Moore, at Cushendall Bay, North of Ireland, 5 feet long and 3 feet wide ! In some specimens the frond is nearly simple, with a few dichoto- mous lobes near the apex ; in others it is once or twice forked, with the margin fringed with dichotomous lobes; and in others the whole frond is repeatedly and regularly dichotomous, the segments narrow and linear. This last state constitutes the N. ocellatum of authors, a plant which, in its typical form, appears distinct enough ; but numerous specimens, kindly communicated to me by Mrs. Griffiths, exhibit such intermediate charac- ters, that I no longer hesitate to unite it with N. punctatum : with which opinion, I am happy to add, Dr. Greville and Mrs. Griffiths coincide. In all its varieties the frond of this species is exceedingly thin and delicate, quite destitute of veins. The tubercles are globose, and thickly scattered over the surface ; the spots of tetraspores large, 1 or 2 lines long, oblong, oval or linear, scattered over the whole surface or confined to a central por- tion of the frond. 2. N. HillicB, Grev. ; frond thiclush, but tender, faintly veined towards the base, roundish, but very irregular in figure, somewhat cuneate at base, variously cleft into oblong, more or less broad, rounded segments ; spots of tetraspores very minute, scattered over nearly the whole frond. Grev. Alg. Brit. p. 80 ; Ham. Phyc. Brit. t. clxix. N. ulvoideum, Harv. Man. 1st edit. p. 57 ; 'Hook. Br. Fl. ii. p. 287 ; Wyatt, Alg. Danm. No. 16. Del. Hilli E. Bot. t. 2190. On rocks, near low-water mark ; rare. Annual ? Winter. Several places on the coasts of Devon and Cornwall. At Torquay, in December, with tubercles very fine, Mrs. Griffiths. Belfast Bay, Mr. Templeton, (Turner). — Fronds tufted, 2 — 4 inches high, with a simple or forked, arched or wavy stem, set with patent or horizontal, alternate or secund branches of about equal length, and which are either naked or furnished with a second or third series; branches cylindrical, about half a line in diameter, acuminate ; ramuli subulate, pinnate or secund, of unequal length. Tubercles spherical, sessile on the smaller branches, or occasion- ally terminating the ramuli, scattered or clustered. Substance cartilagi- nous. Colour a dull purple-red, darker when dry. 3. G. Teedii, Turn. ; frond membranaceous, flaccid (horny when dry), flat, linear, acuminate, repeatedly pinnated with slender, horizontal, distichous, subulate ramuli ; capsules CHONDRUS. 141 globose, on the ramuli. Grev. Alg. Brit. p. 96 ; Hook. Br. Fl. ii. p. 301 ; Wyatt, Alg. Danm. No. 28 ; Harv. Phyc. Brit. t. cclxvi. Sph. Teedii, Grev. Crypt, t. 356. On rocks at extreme low water, very rare. Perennial. Elberry Cove and Tor Abbey Bocks, Mrs. Griffiths. — Fronds 2 — 5 inches high, from half a line to a line in width; stem cylindrical, soon becoming compressed, and finally flattened, either forked at the base or simple, set at intervals of about a line with long, horizontal, distichous branches, attenuated at each end, and pinnated with a second or third series of patent subulate ramuli ; the whole forming a broadly ovate or fan-shaped frond. The ra- muli are frequently very much lengthened out and filiform. Tubercles have not yet been found in this country ; they occur on the ramuli. Co- lour purplish, becoming brighter in fresh water, and finally yellowish. Substance flaccid, but becoming horny when dry, and not adhering to paper. 4. G. mamillosuSj Good, and Woodw. ; frond thick, flabel- liform, channelled, irregularly dichotomous; segments ob- long-wedge-shaped ; tubercles roundish or ovate, supported on little stalks, scattered over the disk of the frond. Grev. Alg. Brit. p. 127 ; Hook. Br. Fl. ii. p. 302 ; Wyatt, Alg. Danm. No. 117; Harv. Phyc. Brit. t. cxcix. ; E. Bot. t. 1054. On rocks and stones near low-water mark, common. Perennial. Au- tumn and winter. — Fronds 3 — 6 inches high, cylindrical at base, but gra- dually widening into a compressed, and finally flat, wedge-shaped frond, which is either once or twice forked or repeatedly dichotomous ; the seg- ments all wedge-shaped, from a line to half an inch in breadth ; the apices acute. Tubercles roundish, borne on short, filiform processes, produced in great plenty by the surface of the upper segments, and which, in cases of imperfect fructification become leaflets. Colour a dark purple. Substance tough. IV. CHONDRDS. [Plate 17, D.] Frond cartilaginous, nerveless, compressed or flat, flabel- liform, dichotomously cleft, formed internally of three strata ; the inner of densely packed longitudinal fibres ; the medial of small, roundish cells ; the outer of vertical, coloured mo- niliform filaments. Fructification : 1, prominent tubercles (nemathecia) composed of radiating filaments, whose lower articulations are at length formed into spores (?) ; 2, tetras- pores collected into sori, immersed in the substance of the frond ; 3, favellidia, immersed in the frond, and scattered over its segments, containing minute spores. — Name, from x;ovfy>of, cartilage. 1. C. crispus, L. ; frond, thickish, cartilaginous, dichoto- 142 PHYLLOPHORA. mous, flat or curled ; segments wedge-shaped, very variable in breadth ; apices truncate, sub-emarginate, or cloven, axils obtuse ; sori concave on one side. Grev. Alg. Brit. p. 129, t. 15 ; Hook. Br. Fl. ii. p. 302 ; Wyatt, Alg. Danm. Nos. 118 and 119; Harv. Phyc. Brit. t. Ixiii. Fucus crispus, E. Bot. t. 2285. On rocky sea shores, very common. Perennial. Spring. — Fronds densely tufted, 2 — 10 inches high, narrow and sub-cylindrical at base, but soon becoming flat, repeatedly forked, very variable in breadth ; segments from I — 4 lines wide, flat or curled ; the axils generally rounded. Sori oval, imbedded in the frond, prominent on one side and concave on the other, containing minute cruciate tetraspores. Colour, various shades of purple or greenish ; in shallow pools near high-water mark, generally yellow or pale green. Substance horny when dry. This is the Carriyeen, or Irish Moss of the shops. 2. C. norvegicus, Gunn. ; frond linear, dichotomous, flat, the axils patent, the apices rounded ; favellidia minute, im- bedded in the substance ; nemathecia prominent, sessile, scattered over both surfaces of the frond. Grev. Alg. Brit, p. 130 ; Wyatt, Alg. Danm. No. 120 ; Harv. Phyc. Brit. t. clxxxvii. ; E. Bot. t. 1080. Rocky shores near low-water mark, rare. Annual ? September to March. Chiefly in the south of England and Ireland. Saltcoals, Rev . D. Landsborough. — Fronds 2 — 3 inches high, with a cylindrical stem from a quarter to half an inch long, thence flat, 1 or 2 lines wide, and repeatedly dichotomous. Favellidia (very rare, and hitherto only found by Mrs. Griffiths), about the size of poppy-seed, imbedded in the frond, containing a mass of minute spores. Warts or nemathecia common, roundish, nearly a line in diameter, scattered over the frond, composed of beaded filaments. Substance thinner than in C. crispus. Colour a deep, rather dull, blood- red. V. PHYLLOPHORA. Grev. [Plate 18, A.] Frond stipitate, rigid-membranaceous, proliferous, nerve- less or with a vanishing nerve, cellular ; cells minute, angu- lar, gradually smaller towards the surface. Fructification : 1, tubercles (favellidia ?) scattered over the frond, contain- ing masses of minute spores ; 2, warts (nemathecia} seated on the frond, composed of radiating, moniliform filaments, whose lower articulations are at length converted into spores; 3, tetraspores, collected into sori, either towards the apex of the frond, or in proper leaflets. — Name, from .] Frond purplish or rose-red, filamentous, jointed ; filaments single tubed. Fructification : 1, gelatinous receptacles (fa- 170 SEIROSPORA. vellte) terminating the branches, surrounded by an involucre and containing several clusters of pear-shaped spores com- pacted together ; 2, tetraspores affixed to the ramuli, scat- tered. — Name, in honour of Baron von Wrangel, a Swedish naturalist. Nearly related to Griffithsia, from which this genus chiefly differs in having scattered tetraspores. 1. W. multifida, Huds. ; stems setaceous, pinnate or bi- pinnate, articulated, each joint bearing a pair of opposite, slender, pinnato-multifid, incurved ramelli, or whorled with numerous forked ramelli; joints of the stem many times longer than broad. Harv. Phyc. Brit. t. xxvii. Griffithsia multifida, Hook. Br. Fl. ii. p. 338 ; Wyatt, Alg. Danm. No. 43. Conf. multifida, E. Bot. t. 1816— @. pilif era : ramelli very long, sub-simple and hair-like. On perpendicular rocks, near low-water mark. Frequent on the south coasts of England. West of Ireland. Belfast Bay, Mr. W. Thompson. Rare in Scotland, Saltcoats, Miss Margaret Landsborough. ft. Torquay, Mrs. Griffiths — Stems 4 — 6 inches long, as thick as bristles, undivided, pinnated or bipinnated with one or two series of long, simple, distichous, patent branches, articulated; the joints very variable in length in different specimens, 5 — 10 times longer than broad, single-tubed, each bearing an opposite pair of slender, pinnato-multifid or sub-dichotomous ramelli, 1 or 2 lines long, which in /3. are much drawn out, half an inch long, and either simple or pinnate. Colour a fine transparent rose-red, perishing quickly in the air or in fresh water. Tetraspores minute, elliptical, with a wide border, sessile on the lower part of the ramelli, opposite or secund, occasionally tufted. Favellce roundish, stalked and involucrated, contain- ing clusters of pear-shaped spores. The ramelli are generally described as dichotomous, but they are only so by abortion ; the true mode of branch-- ing is pinnate, They are sometimes whorled, but more usually opposite. VTI. SEIROSPORA. Harv. [Plate 23, C.] Frond rosy, filamentous ; stem articulated, one-tubed, the articulations traversed by jointed filaments; branches jointed. Fructification: 1, Favellce (unknown); 2, oval tetraspores disposed in terminal, moniliform strings. — Name, chain, and (TTropog, a seed. 1. S. Grijfithsiana, Harv. Phyc. Brit. t. xxi. Callith. seirospermmn, Griff, in Harv. Man. ed. 1, p. 113. Cal. versicolor &. seirospermum. Harv. in Hook. Journ. Bot. vol. \.p. 302; Wyatt.Alg. Danm. No. 19. On rocks and Algas, in 4 — 5 fathom water. Very rare. Torquay, Mrs. Griffiths ; Salcombe, Mrs. Wyatf, Torpoint, Plymouth, Rev. W. S". Hore ; Portaferry, Mr. Thompson ; ' Roundstone, W. H. H. ; Arran, Rev. D. CALLITHAMNION. 171 Lcmdsborough ; Kirkwall Bay, Rev. J. H. Pollexfen. — Stem 2 or 6 inches high, setaceous, generally undivided, more or less opake and veiny, set with numerous, sub-distichous, long, simple, alternate, patent branches, the lowest of which are longest, giving the plant, when displayed, a broadly. ovate outline ; the largest frequently bearing a second set of simi- lar branches. All are more or less furnished with sub-dichotomo-multifid, level-topped ramuli, of a narrow obovate outline. Tetraspores globose, in beaded strings at the tips of the hranchlets, several strings generally tufted at each tip. This beautiful plant has the aspect, and many of the micro- scopic characters of strong specimens of Cat. corymbosum, but is at once dis- tinguished by the fructification ; the tetraspores in Seirospora being formed out of the terminal ramuli themselves, the whole ramulus becoming con- verted into a string of bead-like tetraspores. VIII. CALLITHAMNION. Lyugb. [Plate 23, A.] Frond rosy or brownish red, filamentous; stem either opake and cellular, or translucent and jointed; branches jointed, one-tubed, mostly pinnate (rarely dichotomous or ir- regular) ; dissepiments hyaline. Fructification: 1, round- ish or lobed, berry-like receptacles (favellaj seated on the main branches, and containing numerous, angular spores : 2, external tetraspores, scattered along the ultimate branch- lets or borne on little stalks. — Name, from xaXAoj, beautiful, and Qapviov, a little shrub. Section 1. CRUCIATA : ramuli opposite. (Sp. 1 — 7). 1. C.plumula, Ellis ; stems distichously branched, sub- dichotomous, articulated; each joint bearing a pair of short, recurved plumules pectinated on their upper margin. Hook. Br. Fl. ii. p. 339 ; Wyatt, Alg. Damn. No. 138 ; Harv. Phyc. Brit. t. ccxlii. Conf. plumula, Dillw. t. 50. C. Turneri, E. Bot. t. 1637, (not t. 2336).— ft. smaller in every part. In the sea from Orkney to Devon, not uncommon. |3. Devonshire, Mrs. Griffiths. Dublin Bay. — Fronds 2 — 5 inches long, distichously branched ; the branches alternate or irregular, the upper ones longest and most divided, slender, articulated throughout ; every articulation having a pair of opposite, horizontal or recurved ramuli, from a quarter to half a line in length, and about a quarter the diameter of the stem, whose upper margin is pectinated with a second series of subulate branchlets, which, in luxuriant specimens, are often again and again pectinated along their inner faces. Tetraspores minute, spherical, borne on the tips of the abbreviated pectinate ramuli. Favellce large, lobed, dark red, on the main branches. Joints of the stem 3 or 4 times longer than broad, of the ramuli shorter. Colour a fine rose-red. Substance flaccid and tender. C. cruciatum, Ag. ; irregularly divided ; branches linear, 172 CALLITHAMNION. sub-simple, articulated, each joint having two or four oppo- site or quaternate, slender, erect, pinnated ramuli. Hook. Br. Fl. ii. p. 339; Wyatt, Alg. Danm. No. 182; Harv. PJiyc. Brit. t. clxiv. — B. pumilum ; much smaller, the ra- muli more dense, and joints shorter. Cal. pumilum, Harv. in Hook. Br. Fl. ii. p. 339. On mud-covered rocks near low-water mark, rare. South of England and South and West of Ireland. Coast of Down, Mr. W. Thompson. /3. at Miltown Malbay. — Stems 1 or 2 inches high, irregularly divided into a number of long, sub-simple branches, which sometimes bear a second or third series; branches linear, jointed, each joint furnished with two oppo- site or four cruciate, slender, pinnate or occasionally simple, erecto-patent ramuli, from a quarter of a line to a line in length, crowded at the tips of the branches, which, to the naked eye, have a peculiar thickened and darkened appearance. Colour a brownish red. Substance flaccid. Tetras- pores elliptical, dark red, seated on the shortened pinnules of the ramuli. Favellce unknown. Having lately had an opportunity of studying this species in its habitat at Torquay, and finding it to vary much in size, and in the length and composition of the ramuli, I do not hesitate to reduce C. pumilum to it as a variety. 3. C. Jloccosum, Fl. Dan. ; frond capillary, very flaccid, remotely much branched ; branches alternate, erecto-patent, articulated ; every joint producing a pair of opposite, simple, subulate, erecto-patent, minute ramuli ; tetraspores elliptical, pedicellate, produced on the ramuli, near their base. Harv. Phyc. Brit. t. Ixxxi. Cal. Pollexfenii, Harv. in An. Nat. Hist. vol. xiv. p. 186, t. v. /5 — 7. Conferva floccosa, FL Dan. t. 828. On submarine rocks, near low-water mark. Annual. Spring. Very rare. Orkney Islands, Rev. J. H. Pollexfen. Aberdeen, Dr. Dickie. — Densely tufted, 1 — 5 inches long, very slender and flaccid, irregularly di- vided into several principal branches, somewhat dichotomous ; branches naked, or furnished at intervals with short, multifid lesser branches, having an obovate outline ; all the branching alternate. Every articulation of stem and branches bears a pair of slender, and very short, opposite ramuli. On these ramuli, toward their base the pedicellated tetraspores are borne. Colour a bright purplish lake. A most beautiful and distinctly charac- terised plant, of veiy yare occurrence, and seemingly confined to the nor- thern parts of Britain. 4. C. Turneri, Dillw. ; stems rising from creeping fila- ments, erect, simple or slightly branched, pinnated with opposite, spreading, simple ramuli ; articulations of the stem 5 — 10 times longer than broad ; tetraspores clustered, subra- cemose or corymbose ; favellse involucrated, stalked. Harv. in Hook. Br. Fl. ii. p. 339; Wyatt, Alg. Danm. No. 183; Harv. Phyc. Brit. t. clxxix. Conf. Turneri, E. Bot. t. 2339, CALLITHAMNION. 173 (not 1. 1637}. Cer. Turneri, Grev. Crypt, t. 355. Cat. re- pens, Lyngb.; Harv. Man. Ed. 1, p. 115. Conf. repens, Dillw. t. 18 ; E. Bot. t. 1608. Parasitical on several marine Algae, common. — Stems rising from creep- ing fibres, erect, forming a dense globular or elongated tuft, from an inch to an inch and a half high, very slender, once or twice pinnated with op- posite branches similar to the stem, which are occasionally, by abortion, alternate. Articulations variable in length, but generally many times longer than broad. Tetraspores globose, with wide borders, seated along the upper sides of the pinna? at the joints, either stalked or sessile, clustered or solitary. FavellaR stalked, furnished with an involucre, and resembling those of Griffithsia. Colour a tine rose-red. I do not hesitate to unite under this species the C. repens, of authors, which chiefly differs from C. Turneri, in having the rainuli often alternate. 6. C. barbatum, Ag. ; stems (rising from creeping fila- ments) tufted, much and irregularly branched ; branches opposite or alternate, either simple or pinnulated for half their length with minute, opposite, spine-like, erecto-patent ramuli ; articulations 2 or 3 times longer than broad ; cap- sules elliptic-oblong, sessile on the sides of the pinnulae. Harv. Phyc. Brit. t. clxv. On mud-covered rocks within tide-marks. Very rare. Ilfracombe, and on the quay at Penzance, Mr. Ralfs. Dredged at Weymouth, Rev. M. J. Berkeley. — Filaments densely tufted, 1 or 2 inches high, rising from creep- ing fibres, much and irregularly branched ; branches opposite or alternate, of various lengths, and either simple or bearing others, patent, the upper and lesser branches pinnulated for half their length with minute, opposite, spine-like, erecto-patent ramuli, not a quarter of an inch in length, which are deciduous in winter. Articulations 2 or 3 times longer than broad, deeply coloured. Substance meinbranaceous and somewhat rigid, imper- fectly adhering to paper. Colour a brownish or full red. Tetraspores elliptic-oblong, with wide borders, sessile on the sides of the pinnulae. Under the microscope this presents many of the characters of the larger and more branched specimens of C. Pluma, but it is a very much larger, coarser, and more rigid plant, to the naked eye resembling C. Turneri ; the pinnula are proportionally much shorter and more regular, and the tetraspores are of a different shape. Mr. Ralfs says, " Tf I am right, it is a perennial plant, but in winter it loses the small, opposite ramuli. The plant, both at Penzance and Ilfracombe, grows in tufts, and is generally covered with mud." The habitat, it may be observed, is very different from that of C. Pluma. 7. C. Pluma, Dillw.; stems rising from creeping filaments, erect, sub-simple or alternately branched; branches naked below, the upper half pinnated with short, erect, close-set, opposite ramuli ; articulations 2 — 4 times longer than broad ; capsules globose, stalked. Harv. in Hook. Br. Fl. ii. p. 340. Conf. Pluma, Dillw. Suppl. t. F. 174 CALLITHAMNION. On other Algae, generally on the stems of Laminaria aigitata, rare. Bantry Bay, Miss Hutchins. Appin, Capt. Carmichael. Malbay, W. H. H. — Stems rising from creeping fibres, a quarter to half an inch in height, either simple or divided into a greater or less number of alternate, or sometimes opposite branches, which are naked below, their upper half pectinato-pinnate. PinncB opposite, short or long, simple, very erect. Tetraspores globose, with wide borders, stalked or sessile, sometimes clustered, often terminating the pinnulae. Joints of the stem and branches 2 — 4 times longer than broad. Colour a full rose-red. Nearly allied to C. Turneri, but much smaller and with shorter joints. Section 2. FRUTICOSA. Main stems robust, opake, or nearly opake, sub-simple, filled with longitudinal (rootlike) fila- ments. Ramuli alternate (sp. 8 — 13). 8. C. Arbuscula, R. Br. ; stems naked below, robust, car- tilaginous, main branches set with shorter branches, which are densely clothed on all sides with minute, imbricated, pin- nated ramuli (or plumules) ; ultimate pinnules simple or forked, recurved, acute, their joints twice as long as broad ; tetraspores lining the inner faces of the pinnules. Harv. in Hook. Br. Fl. ii. p. 340 ; Harv. Phyc. Brit. t. cclxxiv. Con- ferva Arbuscula, R. Brown ! Dillw. t. 85 ; E. Bot. t. 1916. Dasya spongiosa, Ag. On rocks and stones between tide-marks. Perennial. Common on the northern and western shores of Scotland and Ireland. Very rare on the eastern shores of Scotland. Frith of Forth, Drs. Greville and Arnott. Aberdeen, Dr. Dickie. — Stem cartilaginous, inarticulate, as thick as a crow- quill at base, 3—8 inches long, shaggy with fibres, but destitute of branches below, divided above, the branches set with a second and third series similar to themselves, but shorter, the smallest about two lines long ; all quadrifari- ous, and densely clothed on all sides with minute, pinnated ramuli or plu- mules. These latter are not a quarter of a line long, simply pinnate, the pinna? long, subulate, very patent or falcato-reflexed. Articulations of the ramuli once and a half or twice as long as broad. Tetraspores spherical, with wide borders, lining the inner face of the ramuli. Favellce roundish or lobed, mostly in pairs. Colour a very dark vinous red. Substance of the stem cartilaginous, of the ramuli flaccid. This is the original Conferva Arbuscula of Brown, whose specimens I have examined. The figure in Eng. Bot. is not very characteristic : that of Dillwyn is better, except the colour, which is far too bright. 9. C. Brodi&i, Harv. ; stem sub-opake, veiny, obscurely jointed, slender, simple, furnished throughout with patent, alternate branches, which bear at each joint short, quadrifa- rious, secondary branches, with a narrow, hastate outline ; secondary branches laxly set with short, quadrifarious plu- mules ; ultimate pinnules erecto-patent, obtuse, sub-simple ; tetraspores roundish, sessile near the tips of the pinnules, CALLITHAMNION. 175 mostly solitary. Hook. Br. Fl. ii. p. 340; Wyatt, Alg. Danm. No. 184 ; Harv. Phyc. Gen. t. cxxix. In the sea, on other Algae, rare. Forres, Mr. Brodie. Coast of Northum- berland, Mr. Robertson. Torquay, Mrs. Griffiths and Miss Cutler. Corn- wall, Mr. Ralfs. Miltown Malbay, W. H. H. Annual. Spring.— Stems 1 — 3 inches high, generally undivided, as thick or thicker than hogs' bristles at base, attenuated upwards, inarticulate or with imperfect joints (which are about twice as long as broad, and full of veins), closely beset throughout its whole length with long, simple, quadrifarious branches, of which the lowest are longest, becoming gradually shorter upwards, often again fur- nished with a second or even third series, and all furnished at the (more or less perfect) joints with short, pinnated ramuli or plumules ; the pinnules erecto-patent, either simple, or having a few secund or alternate pinnulas tapering upwards, but not to an acute point. Joints of the ramuli about twice as long as broad. Tetraspores globose, on the inner face of the ra- muli near the tip, generally solitary, occasionally 2 or 3 together, or on short secund processes of the ramuli. Favella roundish, large, solitary, or in pairs, borne by the lesser branches. Colour a brownish red. Substance cartilagineo-membranaceous, flaccid. The general outline of the frond is ovate. Specimens bearing favellte are more delicate and transparent in the stem than the others. 10. C. letragonum, With. ; outline of the frond ovate ; stem cartilaginous, sub-simple, setaceous, somewhat opake, veiny, set with sub-qtiadrifarious, lateral branches, furnished sometimes with a second or third series; penultimate branches pellucidly jointed, slender, elongate, set with short, alternate, patent, level-topped plumules, the lowest of which are simply pinnate, the upper sub-bipinnate ; ramuli incurved, narrowed at base, suddenly acuminate, their articulations once and a half as long as broad, constricted at the joints ; tetraspores exceedingly minute, oval, near the tips of the ramuli. Harv. Phyc. Brit. t. cxxxvi. ; Harv. in Hook. Br. Fl. ii. p. 334 ; Wt/att, Alg. Danm. No. 90. Conf. tetragona, E. Bot. t. 1690. Near low-water mark, on the larger Algae, frequent. Annual. Summer. — Fronds 3 — 6 inches long, stem thicker than a hog's bristle at base, gra- dually attenuated upwards, repeatedly branched alternately, the branches irregularly quadrifarious, the lowest longest, and set with one or more series of lesser branches, the upper gradually shorter and more simple ; the general outline of the frond being ovate, with its principal divisions tapering to the apex. Stem more or less obscurely jointed, naked or clothed with squavrose ramuli ; branches set with quadrifarious or sub-dis- tichous, alternate, pinnato-multifid, minute ramuli, about half a line in length, contracted at base and suddenly acuminate at apex. Substance firm, cartilagineo-membranaceous. Tetraspores excessively minute, sessile, elliptic or roundish, secund, on the upper ramuli. Favellce solitary or in pairs, large. Colour full or brownish red, becoming darker in drying. 11. C. brachiatutn, Bonnem. ; outline of the frond lanceo- 176 CALLITHAMNION. late ; stem cartilaginous, sub-simple, setaceous, somewhat opake, veiny, set with sub-quadrifarious, lateral branches, of- ten furnished with a second series ; penultimate branches pellucidly jointed, slender, elongate, set with short, alternate, very erect, level-topped plumules, the lowermost of which are most simple ; ramuli erect, subulate, not narrowed at base, gradually tapering to a fine point, their articulations twice as long as broad, cylindrical ; tetraspores minute, oval, near the tips of the ramuli. Harv. Phyc. Brit. t. cxxxvii. C. granulatum, Harv. in Hook. Br. Fl. ii. p. 334 (not of Ag.}. C. Harveyanum, J. Ag. in Linn. xv. p. 45. Parasitical on Algae, near low-water mark ; frequent. A more slender plant than the preceding, with longer articulations in the stem, but chiefly distinguished by the different form of the ultimate ramuli. In C. tetrago- num the ramuli are mucronate, or suddenly tapering at the point; here they are subulate, tapering from the very base. Still, this character may possibly be variable. 12. C.teiricum, Dillw.; rigid; branches densely ramulose, shaggy below, plumulate above ; plumules crowded, quadri- farious, simply pinnate ; pinnae acute, tapering to the base, erecto-patent; articulations 2 or 3 times longer than broad ; tetraspores elliptical, minute, on short, lateral processes of the pinnules. Harv. in Hook. Br. Fl. ii. p. 342 ; Wyatt, Alg. Damn. No. 141 ; Harv. Phyc. Brit. t. clxxxviii. Conf. tetrica, E. Bot. t. 1915. In the sea, generally growing on the perpendicular faces of rocks, at half- tide level. Perennial. Common on the rocky coasts of England, and of the west and south of Ireland. — Fronds 2 — 8 inches long, divided into se- veral principal branches, closely covered with long, peculiarly straight and rigid, pinnated ramuli, mixed with simple or irregularly branched ones ; the the branches having a coarse, ropy character. Plumules simply pinnated, the pinnae erecto-patent, contracted at base, attenuated upwards. Colour a dull brownish-red. Substance more rigid than in most, imperfectly ad- hering to paper, very fragile if moistened after having once been dried. Articulations uniformly about once and a half as long as broad. Tetras- pores ] — 3 on each lateral process. Favellce generally in pairs, minute, seated on the pinnae, and nearly terminal. 13. C. Hookeri, Dillw.; stem setaceous, inarticulate or spuriously jointed, simple, set with one or more series of al- ternate, spreading, flexuous branches, the smaller of which are jointed ; all furnished with very patent, pinnated ramuli or plumules ; ultimate pinnules divaricating, their joints twice or thrice as long as broad ; tetraspores along the inner faces of the ramuli near the base. Harv. Phyc. Brit. t. cclxxix. ; Harv. in Hook. Br. Fl. ii. p.. 341. Conf. Hookeri, CALLITHAMNION. 177 Dillw. t. 106. C. lanosum, Harv. L c. ; Wyatt, Alg. Damn. No. 139. On rocks and Algae between tide-marks. Annual. Spring and sum- mer. Cawsie, Messrs. Hooker and Borrer. Not uncommon, from Orkney to Cornwall. — Stem 1 — 3 inches high, setaceous, inarticulate or spuriously jointed (the joints short and filled with veiny fibres), closely furnished throughout with long, simple branches, similar to itself, which again bear a second or third set, either quadrifarious or sub-distichous, flexuous ; the lesser ones jointed, and at the joints bearing very patent, pinnated rarauli or plumules, which are sometimes naked at the base, and either simple or bipinnated above, all the pinnules very patent or divaricating. Joints twice or thrice as long as broad. Tetraspores along the inner face of the ramuli near the base, either solitary or 2 or 3 together. Favellce large, on the branches, irregular. Colour a brownish or rosy-red, in some states pre- served in drying, at other times very fugacious. The specimens of this plant from North Devon and from the South of Ireland, are much more robust and deeper coloured, and of a less delicate substance than those from Torbay and the east of Ireland, and, at first sight, strikingly resemble C. Brodicei, while the latter come nearer C. roseum. A re-examination of the original Conferva Hookeri, and comparison with various varieties of Cat. lanosum, Br. Fl. induce me to unite the latter to the former. It is certainly a very variable plant, but the varieties run insensibly into each other. Section 3. ROSEA. Main stems slender, evidently articu- lated, the articulations pellucid, or traversed by a few longitudinal filaments. Branches decompound-pinnate. Ramuli alternate. (Sp. 14—23). 14. C. roseum, Sm. ; stems much and loosely branched ; secondary branches long, flexuous, sub-distichously plumu- late ; plumules lax, with a roundish outline, crowded towards the tops of the branches ; pinnules long, patent, sub-simple, curved, simply pinnate ; main articulations 4 or 5 times, those of the pinnae 2 or 3 times longer than broad ; tetra- spores elliptical, scattered, near the base of the pinnae. Harv. Hook. Br. Fl. ii. p. 341 ; Wyatt, Alg. Danm. No. 44 ; Harv. Phyc. Brit. t. ccxxx. Conf. rosea, E. Bot. t. 966. Near low-water mark, on mud-covered rocks and Algae. Annual. Sum- mer. Yarmouth, Messrs. Turner and Borrer. Not uncommon, generally distributed. — Stems 3 or 4 inches long, setaceous, in young plants jointed, in older opake and full of veins, set throughout with long, more or less qua- drifarious, patent branches, which are several times irregularly pinnated, till the plant acquires an excessively branched, entangled character; branches furnished more or less abundantly with long, simply or sub- simply pinnated plumules, which are usually crowded in the upper part of the branches, giving the tips (especially of young plants) a dense appear- ance ; the ultimate ramuli elongate, slender, the lower ones usually simple, the upper occasionally pinnulate in the upper part. Tetraspores elliptical N 178 CALL1THAMNION. or spherical, on the inner faces of the ratnuli, 2 or 3 together or solitary. Favellce two or more together on the branches. Colour in young specimens a fine purple-red, in old brownish, becoming brighter in fresh water. 15. C. byssoideum, Arnott ; stems extremely slender, flac- cid and byssoid, much divided ; branches linear-lanceolate, set with long, slender, flexuous, sub-simply pinnate plumules ; joints of the branches eight times, of the ramuli four times longer than broad ; tetraspores solitary, sessile on the pinnae. Harv. in Hook. Br. FL ii. p. 342; Wyatt, Alg. Damn. No. 185 ; Harv. Phyc. Brit. t. cclxii. Near low-water mart, on other Alga?. Whitsand Bay, Dr. Jacob. Not very uncommon. — Stems extremely tender, flaccid and gelatinous, much divided from the base, either with several principal branches thicker than the rest, which bear a great number of lesser branches, or wholly composed of slender, byssoid branches, inextricably entangled together, the main stems in the coarser specimens full of veins ; branches having a linear-lan- ceolate outline, tapering to a point, clothed with long, slender, sub-simply pinnate ramuli, either quadrifarious or distichous, all the divisions alter- nate. Joints of the stem many times longer than broad, of the ramuli about four times longer than broad. Tetraspores elliptical, sub-solitary near the base of the ramuli. Favellce sessile on the stems, frequently three- lobed. This species has the habit and substance of Cal. corymbosum, with which, at one time, I was disposed to unite it. In ramification, however, it more nearly agrees with C. roseum, but is much more slender and delicate. 16. C. polyspermum, Ag. ; tufts globose ; filaments slen- der, delicate, loosely branched, somewhat naked below, disti- chously plurnulate above ; plumules linear-oblong (in out- line); pinnae short, simple, patent, acute, spine-like ; articu- lations of the branches 4 or 5 times, of the ramuli twice as long as broad ; tetraspores lining the inner faces of the pin- na?. Harv. in Hook. Br. FL ii. p. 342 ; Wyatt, Alg. Danm. No. 140 ; Harv. Phyc. Brit. t. ccxxxi. On rocks and the larger Fuci, not uncommon. Annual. Spring and summer. — Tufts globose, 1 — 3 inches in diameter, dense; stems sub- simple below, much branched above in a fan-like manner ; the branches several times divided and set with lesser branches, all the larger ones hav- ing spine-like, alternate, subulate, short ramuli, the larger pinnated with a second series, the uppermost ones occasionally still more compound ; all the ramuli spreading, sometimes reflexed. Joints of the stem and branches torulose, with a narrow tube. Capsules profuse, spherical. Favellce large, roundish or ovate, binate. Colour a dull rose-red or purplish. In drying it adheres less perfectly than some others to paper. 17. C. purpurascens, Sm. ; "purplish-red, repeatedly branched, very slender and tufted, joints slightly turned, thrice as long as broad, with pellucid partitions, those of the CALLITHAMNION. 179 main stems compound ; capsules lateral, sessile." Smith, E. Bot. t. 2465 j Hook. Br. Fl. ii. p. 343. " Gathered on the beach at Brighton by Mr. W. Borrer, who thinks it may be C.purpurascens of Hudson." Sm. — With this I am quite unac- quainted. Mrs, Griffiths informs me she has specimens gathered in Corn- wall, so named by Dawson Turner, and Dr. Goodenough, that are identical with Cal. Brodicei. 18. C. fasciculatum, Harv. ; tufted; branches erect, flex- uous, le vel- topped ; plumules elongate, erect, linear-obovate, truncate ; pinnae long and flexuous, the lowermost simple, appressed, the upper erecto-patent, ramulose at the tip ; ar- ticulations of the branches thrice, of the pinnae once or twice as long as broad, sub-torulose. Harv. in Hook. Br. Fl. ii. p. 343. At Yarmouth, Mr. Borrer. — 2 or 3 inches high, nearly naked at the base, much branched and tufted upwards, bushy, very slender ; the apices of the branches looking, to the naked eye, as if truncated or corymbose ; branches long and flexuous, very erect, their upper half closely plumulate, the plumules long and appressed. Colour a fine purple-red. Articulations of the main stem nearly opake, composed of jointed fibres. Tetraspores rare, sub-solitary, elliptical, at the base of the pinna3. This description, which I now transfer from Br. Fl. was taken from a specimen in Sir W. Hooker's herbarium, marked C. Borreri. It did not appear to me to be the same with Borreri, a species with which, at that time, I was but little acquainted, but having in the interval seen many anomalous varieties of the latter, I fear that the present must be looked on as a very doubtful spe- cies. I have never seen more than Mr. Borrer's specimen. 19. C. Borreri, Sm. ; sub-simple below, much branched in a fan-like manner above, rigid or flaccid; upper branches set with distichous plumules which are bare of ramuli below, closely pinnate above ; pinnae long, patent, simple (or ramu- lose at top), the lowermost longest ; articulations of the branches 2 — 5 times, of the ramuli about twice as long as broad ; tetraspores roundish, sessile in the inner face of the pinnae. Harv. in Hook. Br. Fl. ii. p. 344; Harv. Phyc. Brit. t. clix. Conf. Borreri, E. Bot. 1. 1741. Cal. seminu- dum, Ay. ! Harv. I. c. ; Wyatt, Alg. Danrn. No. 187. On rocks in the sea, rather rare. Yarmouth, Mr. Borrer. South of England, in many places. East coast of Ireland, Miss Ball and Miss Gower. — Filaments sub-simple and somewhat bare of branches, or merely set with short ramuli below, much branched in a fan-like manner above, the branches having a roundish general outline, the tips even of the lesser divisions being singularly blunt and rounded ; upper branches furnished with distichous, alternate plumules, which are bare of ramuli below, and closely pinnate in their upper half, the lowermost pinnae being longest, and some of them occasionally pinnulate towards the tips. Substance either ri- gid or very flaccid and membranaceous, a difference which probably depends N2 180 CALLITHAMNION. on age and situation. Colour a full or pale rose-red, given out to fresh water. Some specimens have a very straggling look, the chief divisions being set with irregular ramuli, having something the character of a young plant of C. tetricum, the uppermost branches only having a few plumulate rainuli. On examination of numerous specimens, in different states, and from various localities, I am induced to unite C. seminudum of Agardh and of ' Br. Fl.' with the older species C. Borreri. The chief differences I can find are, that the state called Borreri is more flaccid, of paler colour, more laxly branched, and having rather longer joints ; differences which, in such variable plants, are not of much value. 20. C. ajfine, Harv. ; much branched; secondary branches of a roundish outline, long, alternately plumulate ; plumules very narrow, linear-clavate, simply pinnate ; pinnae short, erect, increasing in length upwards, attenuate, crowded at top ; articulations of branches 3 or 4 times, of pinnae once and a half as long as broad. Harv. in Hook. Br. FL ii. p. 344. Shores of Bute, on Fuci, Dr. Greville. — Excessively branched, 2 or 3 inches high, bushy; main filaments much divided, set with very numerous, alternate, secondary branches, of a roundish or ovate figure, alternately plumulate ; plumules short, very narrow ; lowermost pinnules distant, short and somewhat spine-like, uppermost elongated and crowded. Colour a deep red. Articulations of the stem four times as long as broad, closely filled with very slender, longitudinal veins. Capsules either in the axils of the pinnae or on the first joint. A doubtful species. 21. C. tripinnatum, Ag. ; frond distichously branched, capillary, decomposito-pinnate ; plumules elongate, obovate, tripinnate above ; upper pinnae long and pinnulate, lower short or abortive, each pinna having at its axil a minute pin- nule ; pinnules long, setaceous ; articulations of the stem 3 — 4 times, of the pinnae about twice as long as broad ; te- traspores oval, lateral, on the axillary and occasionally on the other pinnules. Harv. Phyc. Brit. t. Ixxvii. On rocks, at extreme low-water mark, very rare. Annual. April and May. Roundstone Bay, Mr. M'Calla. Plymouth, Mr. Rohloff. — Fila- ments 1 — 2 inches high, slightly tufted, perfectly distichous, having a cir- cumscribed, fan-like outline, about triply pinnate ; the primary branches or plumules having an obovate outline. These primary branches are bi- pinnate above, and simply pinnate towards the base, but the most striking character is a minute axillary ramulus rising from the first articulation of each pinnule. Colour a fine crimson, and substance delicate, closely ad- hering to paper. This species has much of the aspect of the following, but in its microscopic characters is nearer to C. Borreri. 22. C. gracillimum, Ag. ; frond distichously branched, fan- shaped ; filaments capillary, decomposito-pinnate ; upper plumules long, narrow-ovate or lanceolate, patent, bi-tripin- CALLITHAMNION. 181 nate ; articulations of the stem cylindrical, 3 or 4, of pinnae 2 or 3 times longer than broad ; tetraspores on the tips of the pinnules. Harv. in Hook. Br. Fl. ii. p. 345 ; Wyatt, Alg. Danm. No. 45. On mud-covered rocks near low-water mark. Pier, Torquay, Mrs. Griffiths. Milford Haven, Mr. Ralfs. Falmouth, Miss Warren. Ply- mouth, abundantly, Rev. W. S. Hore, &c. — Filaments 1 — 4 inches high, irregularly branched, exceedingly slender, distichous; main branches few, unequally plumulate for their whole length; lower plumules short, vaguely pinnate ; upper from half an inch to an inch long, narrow-ovate or lanceo- late, acute, patent, bi-tripinnate ; outline of the principal branches broadly ovate. Colour rose-red. Tetraspores minute, elliptical, on the tips of shortened pinnulae. Favellce roundish, lobed, on the principal branches. 23. C. thuyoideum, Sm. ; repeatedly branched in an alter- nate manner, distichous ; branches set with alternate, lanceo- late, narrow, bipinnate plumules ; articulations of the stem 2 — 6 times longer than broad ; capsules on the tips of the pinnulae. Harv. in Hook. Br. Fl. ii. p. 346 ; Harv. Phyc. Brit. t. cclxix. Cow/, thuyoides, E. Bot. t. 2205. Cal. tri- pinnatwn, Harv. I. c. (not of Agardh) ; Wyatt, Alg. Danm. No. 186. On rocks near low-water mark, rare. Yarmouth, Mr. Borrer. Ply- mouth, Mr. Sconce. Pier, Torquay, Mrs. Griffiths. Wicklow. Porta- ferry, Mr. W. Thompson. Roundstone, Mr. W. M'Calla. — Frond 1 or 2 inches high, sub-simple below, alternately branched above, the branches distichous, generally having two or more series of lesser branches, which are also alternate ; the minor branches, and sometimes all the divisions of the frond, set at every joint with alternate, patent, closely bipinnate plu- mules, of a very narrow, linear-oblong figure. Articulations of the stem very variable in length in different specimens ; in some twice, in others six times as long as broad, more or less swollen at the joints. Tetraspores on the tips of shortened pinnulae. Colour a fine rose-red. Substance soft and flaccid. The first plumule of the branches or pinnule of the plumules frequently rises from the axil, especially in a variety having shorter joints to the stem than usual, which led me in Br. Fl. to regard this variety as the Cal. tripinnatum of Agardh, a species, one of whose chief characters is this axillary ramulus. Agardh's plant proves, however, on inspection of authentic specimens, to be very different, and, having been recently disco- vered in Britain, is above described. Section 4. CORYMBOSA. Stems articulated ; ramuli dicho- tomous. (Sp. 24—26.) 24. C. corymbosum, Sm. ; capillary, flaccid, gelatinous; secondary branches alternate, excessively dichotomous, sub- flabellate, level-topped ; ramuli dichotomous, byssoid ; arti- culations of the branches 8 — 10 times longer than broad ; 182 CALLITHAMNION. tetraspores solitary, axillary. Harv. in Hook. Br. Fl. ii. p. 346 ; Wyatt, Alg. Danm. No. 22 ; Harv. Phyc. Brit. t. cclxxii. Conf. corymbosa, E. Bot. t. 2352, (joints too short). On Algae, near low-water mark, and on rocks, not uncommon. — 1 — 3 inches high, frond with a more or less evident principal stem, which is ca- pillary below, byssoid above, and closely set with long, alternate branches, which are more or less divided ; the penultimate ones having alternate, dichotomous, multifid branchlets of an obovate outline, rounded at top, or somewhat level-topped. The branching of these ramuli is subject to much variation, sometimes being nearly regularly dichotomous, at other times having an alternate character, but the plant is well marked to the naked eye by the peculiar, level-topped or corymbose appearance of the smaller branches, joined to their slender, byssoid aspect. Tetraspores minute, seated on the forked ramuli immediately below the furcation, thus seem- ingly axillary. Favellce binate, in the axils of the branches. Colour a rose, or purplish red. Substance exceedingly flaccid and gelatinous, ad- hering most closely to paper, and having a fine gloss when dried. 25. C. spongiosum, Harv. ; stems robust, cartilaginous, more or less opake and veiny, branched in every direction ; branches thickly set with dense, quadrifarious, repeatedly di- chotomous, round-topped branchlets; axils patent; apices short, bifid ; articulations of the branches swollen at the joints, thrice as long as broad. Harv. in Hook. Br. Fl. ii. p. 346 ; Wyatt, Alg. Danm. No. 93 ; Harv. Phyc. Brit. t. cxxv. On rocks in the sea, generally such as are perpendicular, and on other Algas. Dunleary, 1802, Mr. Templeton. South of England and coasts of Ireland and Scotland. — Fronds 2 — 4 inches high, flaccid, soft, holding water like a sponge; stems shrubby ; branches long, spreading in every di- rection, thickly clothed with short, secondary branchlets, about half an inch in length, which are again covered with a third set, which are dicho- tomously divided, and, spreading on all sides, give the plant a rounded, bushy character. Main articulations veined. Tetraspores solitary, axil- lary. Favellce roundish or lobed. To the naked eye this plant has some- thing the habit of C. Arbuscula, while, in its microscopic characters, it comes nearer C. corymbosum. It is, however, a much coarser plant than the latter, void of gloss when dry, and of a duller colour. The joints are uniformly shorter, the ramuli more regularly dichotomous, dense and qua- drifarious, and the axils more patent. It was originally discovered by Mr. Templeton, in the station in which I afterwards gathered it 30 years later, a fact of which I was ignorant when I first described it in ' British Flora.' 26. C. pedicellatum, Dillw. ; stems setaceous, loosely and irregularly branched ; branches naked, or set with short, al- ternate, somewhat tufted, sparingly dichotomous branchlets; apices obtuse ; articulations variable, mostly very long ; te- traspores solitary, elliptical or pear-shaped, axillary, stalked. CALL1THAMNION. 183 Harv. in Hook. Br. FL ii. p. 347; Harv. Phyc. Brit. t. ccxii. ; Wyatt, Alg. Danm. No. 94. Conf. pedicellata, E. Bot. t. 1817. On rocks, &c. near low-water mark, not uncommon. Summer. — Fila- ments 2 — 8 inches high, rather flaccid, as thick as horse-hair , branches long, and little or much divided, springing from near the base, beset with short, dichotomous ramuli, which are often crowded at the tips, so as to give the plant a pencilled appearance ; apices always rounded and obtuse. Articu- lations extremely variable in length in different specimens, in some four, in others twelve times longer than broad. Colour a fine red, which is ra- pidly given out in fresh water, and becomes in the herbarium a dull dingy brown. Tetraspores elliptical or pear-shaped, very dark, raised on little colourless stalks situated in the axils of the branches. Pavellee large, sin- gle or in pairs, on the stems. Section 5. PULVINATA. Filaments short, densely tufted, forming cushion-like tufts, or spreading in velvetty patches. (Sp. 27—29). 27. C. Rothii, L. ; widely spreading, densely tufted ; fila- ments slender, short, erect, dichotomous; branches long, straight, appressed ; articulations twice as long as broad ; tetraspores clustered, borne on short, terminal, sub-corym- bose ramuli. Harv. in Hook. Br. FL ii. p. 347 ; Harv. Phyc. Brit. t. cxx. B; Wyatt, Alg. Danm. No. 188. Conf. Rothii, E. Bot. t. 1702. — /3. purpureum ; filaments very mi- nute, forming continuous velvetty patches, slightly branched. Cat. purpureum, Harv. Man. Isted. I, p. 116. Byssus pur- purea, E. Bot. t. 1 92. On marine rocks, above half-tide level. Perennial. Fruiting in winter. — Filaments a quarter of an inch to nearly an inch in height, forming large velvetty patches, of a deep red or purple colour. Branches few and very erect, either dichotomous or alternate, equal. Fructification, as first pointed out by the late Capt. Carmichael, frequently produced in the win- ter months. 28. C. Jloridulum, Dilhv. ; filaments short ; densely tuft- ed, fastigiate, sparingly branched ; branches alternate or sub-dichotomous, nearly simple, appressed; articulations thrice as long as broad ; tetraspores minute, oval, borne on very short, closely appressed pedicels, ranged in a secund manner along the upper branches. Harv. I. c. p. 348 ; Harv. Phyc. Brit. t. cxx. A. Conf.Jloridula, Dillw. Suppl. t. F; Wyatt, Alg. Danm. No. 219. On marine rocks, near low-water mark. West of Ireland, extremely common. Orkney, Dr. Pollexfen. Laud's End, Mr. Ralfs, — Filaments 184 CALLITHAMNION. about an inch high, forming dense, fastigiate tufts, very slender and of equal diameter throughout, furnished with a few long, simple, alternate, very erect or appressed branches, some of which bear, near the apex, seve- ral alternate or secund, closely appressed ramuli, the lowest of which are longest, the upper gradually shorter, giving the apices of the branches a corymbose or level-topped character. Joints fully thrice as long as broad, sometimes rather longer. The fortunate discovery of the fruit by Mr. Ealfs, in April, 1840, affords at length a satisfactory character by which this long-doubtful plant may be distinguished from C. Rothii. 29. C. mesocwpum, Carm. ; " filaments minute, csespitose ; branches virgate, erect ; articulations 4 or 5 times longer than broad ; capsules elliptical, on long pedicels." Carm. MSS. Harv. 1. c. p. 348. Rocks at the extremity of low-water mark. Appin, Capt. Carmichael. — Tufts contiguous, forming a broad, shaggy, purple crust. Filaments 2 or 3 lines long, sparingly branched ; branches long, straight, erect, simple and sub-secund. Tetraspores crowded about the middle of the filaments, secund or opposite, on long, single-jointed or forked peduncles; the cap- sules, in the latter case, either in the axils or substituted for a branch of the fork. I could not discover that it sprung from creeping filaments." Carm. MSS. This appears to come very near C. strictum of Agardh. Section 6. PARASITICA. Minute parasites. (Sp. 30 — 31.) 30. C. sparsum, Harv.; "filaments minutely tufted, scat- tered, sparingly branched ; branches spreading, unequal ; articulations twice or thrice as long as broad ; tetraspores obovate, sessile, mostly axillary." (Carm.) Harv. I. c. p. 348. On old stems of Laminaria saccharina, at Appin, Capt. Carmichael. On Conf. rupestris at Miltown Malbay. — Scarcely a line high, forming mi- nute, scattered tufts. Stems nearly simple, erect, slightly branched beyond the middle ; branches erecto-patent, alternate or secund, of unequal length ; the apices obtuse. This is probably the C. floridulum of Lyngbye, Hyd. Dan. p. 136. It is better distinguished from C. Rothii by its minute size and scattered habit than by any peculiarity of branching. The fruit, ac- cording to Capt. Carmichael is, however, very different. 31. C. Daviesii, Sm. ; rose -red, minute, tufted, much branched ; branches flexuous or straight, scattered or close, erect, more or less furnished with short, sub-secund ramuli ; articulations 3 or 4 times longer than broad. Harv. in Hook. Br. Fl. ii. p. 348 ; E. Bot. t. 2329. C. virgatulum, Harv. 1. c. p. 349 ; Wyatt, Ala. Damn. No. 189. C. lanu- ginosum, Lyngb. Harv. Man. ed. i. p. 117. Conf. lanugino- sa, Dillw. t. 45. C. secundatum, Ag. Harv. Man. ed. i. p. CHLOROSPERME.E. 185 Parasitical on the smaller Alga, generally on Ceramium rubrum. — Fila- ments 2 or 3 lines high, forming elegant, pencilled tufts, much branched ; branches straight or somewhat flexuous, erect or slightly spreading, close or distant, the upper ones often closely set with minute, bud-like, 1- or 2- jointed ramuli. Capsules minute, elliptical, solitary or clustered. I fear the distinctions pointed out in Br. Fl. between C. Daviesii and viryatu- lum cannot be depended on ; the latter appears to be merely a more ad- vanced state of the former : nor can I discover any permanent characters by which C. lanuginosum and C. secundatum, Ag. may be distinguished. Cat. Daviesii bears a very close resemblance to Trentipohlia pulchella, a fresh-water Alga, inhabiting mountain streams. SUB-CLASS III. CHLOROSPERME^E OR CONFERVALES. Harv. in Mack. Fl. Hib. part'\\\. p. 220, (1836) ; ZOOSPER- , J. Ag. Alg. Medit. p. i. (1842). NOSTOCHINE.E, ULVACE^E, CONFERVOIDE.E (in part.} Ag. Syst. pp. xv. xxxii. ZOOSPER- ME.E and SYNSPORE.E, Dne. Sc. Nat. xvii. p. 305. CONFER- VACE^: and part of PHYCE^E, Endl. PI. 3d Suppl. p. 10, 19. CONFERVACE.E and part ofFuc^CEM, Lindl. Veg.Kingd. pp. 14, 20. (DiATOME^E, or DIATOMACE^E, of author s, are also a part of this sub-class). DIAGNOSIS. — Plants green, rarely a livid purple. Fructi- fication : dispersed through all parts of the frond, the whole colouring matter being capable of conversion into propagula ; 1, spores (Sporidia, Ag.), green or purple, formed within the cells, often at maturity vivacious, moving by means of vibratile cilia ; 2, coniocystae (Ag.), or external vesicles, containing a dense, dark-coloured, granular mass, and finally separating from the frond. Marine, or (more generally) found in fresh-water streams, ponds, and ditches, or in damp situations. (The marine species of this sub-class are alone described in the present work}. The plants of this sub-class are, in the vast majority of cases, at once distinguished from all other Algae by the bright 186 CHLOROSPERME^E grass-green or blue-green colour of the frond. A very few are tinged with lurid purple, and a few others with brown. A simplicity of structure, and fructification dispersed through the whole colouring substance of the frond, not confined to distinct conceptacles, combined with the herbaceous green colour just spoken of, are the marks by which we recognize a Chlorospermatous Alga. When we examine these plants a little more closely, with high magnifying powers, we ob- serve that the spores of a large number of them, perhaps of all, are, just at the time of their emission by the parent plant, clothed with vibratile cilia, and endowed with a peculiar mo- tion, strongly resembling the voluntary motion of animalcules. The little spore, whilst contained within the mother cell, commences life by knocking continually against the walls of the enclosure until it has burst through them into the sur- rounding water ; and then, with many gyrations and rapid changes of place, it swims about by means of the cilia with which it is furnished, until it reaches a substance on which it can rest and attach itself. Once attached, its seemingly vo- luntary motions cease. The cilia are absorbed or perish. The semblance of animal life is laid aside, and the vegetable cellule commences the growth natural to its kind, and finally becomes a plant like its parent. Some observers claim for it an animal life during the season of its ciliary movements, and certainly there is a very striking similarity between these movements and the movements which wTe observe in the ova of many of the lower animals, particularly of the class Radi- ata. But that it is a resemblance, a connexion of analogy only, I can scarcely doubt. All must admit that the two great kingdoms of animated nature — animals and plants — (for that plants are endowed with a life analogous to that of animals can no longer be doubted) — approach each other, through the lower members of either kingdom, and seem al- most conterminous. In the spores of these Algae we find one point of seeming contact, but this is laid aside on the commencement of the development of the frond. In some of this sub-class, as in the Diatomaceee and Oscillatoriete, the motion is not always confined to the spore, but the fully formed frond enjoys this singular power in a greater or less degree through the whole of its life-time. And, if you will have it so, the movements of the sensitive plant and of He- dysarum gyrans are further instances, taken from among the higher vegetables, of a movement, to all appearance sponta- neous, perhaps voluntary. And if animals be distinguished CHLOROSPERMEjE. 187 from plants by their voluntary motions only, here are cases which seem to show that the distinction is one of degree and not of kind. And pursuing such a train of thought, I can hardly call it a thread of reason, we are led to question the absolute distinctions between the two great kingdoms of na- ture, whether a plant and an animal be not really fellow-mem- bers of a single fraternity, and not, as commonly supposed, members of distinct organic creations. But in so question- ing the absoluteness of the distinctions between animal and vegetable life, we overlook not merely the crowd of other cir- cumstances connected with animal and vegetable existence which would bear to the other side of the argument, while we fix our attention strongly on a few isolated facts that appear to make out our point : — we not only do this, but we shut our eyes to another fact with which no naturalist who has entered at all into questions of affinity can be unfamiliar, namely, that in no case do we see any group in nature in that state of entirety, unconnexion, or nudity, which will enable us to fix its limits with mathematical precision. Are we therefore to doubt that there are limits, because we can- not readily see them ? Or that absolute differences do not exist because they pass our acuteness to make plain ? I can hardly think this ; and therefore is it that all the arguments brought forward in favour of the unity of animal and vegeta- ble life appear to my (perhaps prejudiced) mind illusory ; and instead of making me more satisfied that the connexion has been proved, remind me merely of those " False views, like that horizon's fair deceit, When earth and heaven hut seem, alas, to meet !" The question is too wide to discuss at large in the present place, nor is it of much practical importance, however inte- resting it may be in a speculative point of view. For all practical purposes vegetable and animal life are as opposite as the poles of a magnet. They are like two opposite and equal forces in juxta-position : there are innumerable points between the two centres of force in which one or other force preponderates in a greater or less degree :• — there is also one point at which neither force preponderates ; a middle point, a point of equilibrium or rest. Applying this illustration to to the animal and vegetable kingdom, such a middle point would be a point of death or annihilation — a chasm, however narrow, separating conterminous countries, at one side of which animal life is manifested, but in its lowest conceivable 188 CHLOROSPERME^:. phase ; and at the other side vegetable life, in an equally low condition. Some such boundary seems to sever such animals as the- sponges, from such vegetables as the less perfect chlorospermatous Algae — but our present knowledge of either tribe is insufficient to permit us clearly to define in words what the exact limits of this bounding line may be. In such a case it is much safer to leave the point undeter- mined, seeing that the probabilities are greatly in favour of the belief that, could we know the matter perfectly, such a boundary line would be discovered. The least organized of the Chlorosperms consist of a single cell, containing a granular matter called endochrome, identi- cal with that found in the cells of the higher vegetables. These very simple plants usually multiply by spontaneous fissure, the internal mass separating into two or more parts, round which a membrane is formed, and which thus be- come cells developed within the walls of the original cell. These cells burst through the mother-cell and become dis- tinct plants, propagating others at maturity in a similar way. Such is the method of increase in the Protococcus or Red- snow plant, whose sudden appearance is readily accounted for by this process of multiplication, by which, in a very few generations some millions of individuals will result from one original cell. If the plant have existed on the surface of the soil on which the snow- falls, its progress upwards through the snow, as new individuals are produced, will be very ra- pid, and thus vast spaces, many feet in thickness, are frequently tinged by a plant of extreme minuteness — so small, that except when seen in masses, it is scarcely appre- ciable by the eye. Sir John Ross encountered it in Baffin's Bay, covering tracts of miles in extent, and often penetrating to the depth of ten or twelve feet. Other simple Chlorosperms are propagated by the conjuga- tion of two cells. This is the case in the Diatomaceae and DesmidiaceoB and in many of the Confervoid tribes. In the case of the simpler Desmidiacete, where the frond consists of a single cell, two fronds come together — a passage is formed from one to the other, and in the intermediate space the whole contents of both the parent-cells are poured, resulting in the fructification or spore. The history of such plants is analogous to that of annuals, which die when they have perfected their seeds. But besides this mode of propagation, they are likewise multiplied by the vivifi- cation and growth of the green matter with which they are CHLOROSPERME^l. 189 filled. This matter, when mature, becomes granular, and is converted into those active spores (or zoospores) whose ani- mal motions I have already mentioned ; and which are pro- bably analogous to the gemmae or buds, by which more per- fect plants are propagated. This, at least, is the opinion of Mr. Ralfs, one of the most accurate observers of these minute plants. The frond in others, a little more advanced in organization, consists of several cells strung together in filaments, such as we find in Conferva and its allies. These filaments are either simple or branched, and are increased, either by additional cells continually added to the growing apices, and as it were budding out of the old cell ; or else by the bi- partition of the first-formed cells. In the first case, a little bud-like body is formed at the apex of an old cell, which lengthens and widens until it attains the dimensions proper to the species ; when it stops, and gives birth to a bud of like character. In the second case, a transverse separa- tion takes place in the middle of the endochrome of an old cell ; a partition or dissepiment is gradually formed, and at last, two cells result from what had been one, and lengthen till they attain their normal state, when each is again capable of this fissiparous division. Such appears to be the mode of growth in Conferva melagonium, area, &c. ; while most of the CladopUora} grow by budding. The difference, however, is more apparent than real, for a fissiparous division takes place in both cases. The Confervas are commonly propa- gated by zoospores ; but sometimes form sporangia, elabo- rated in their cells. From the filamentous Conferva the passage is easy into the Batrachosperrnaceae, where a com- pound frond is built up by the union in bundles and wrhorls of a number of filaments ; and also, through Anadyomene, into the Siphonaceae and Ulvaceae, where the frond assumes a multitude of forms, expanding into membranes or contracting into hollow tubes. In some of the highest members of the sub-class, as in the Caulerpacese, there is an obvious dis- tinction of organs into root, stem and leafy appendages ; but even in these, high in structure as they appear, no distinct conceptacles of fruit have yet been observed. The Chlorosperms are more widely diffused than any other Algae. A comparatively small number are found in the waters of the sea. A far larger proportion inhabit fresh- water rivers, lakes and ponds, ditches, bog-holes, the gutters of houses and sewers ; — in fact, anywhere that fresh or 190 CHLOROSPERME^E. unfresli water may lie ; nor are they absent from the hot springs of volcanic regions, and are capable of vegetating wherever moisture and a moderate temperature prevail. Thus universally dispersed, they answer many a good pur- pose in the household of nature, and are specially useful in purifying the water in which they live. Unsightly as the green scum may be which they form on its surface, the growth is a renovating process, in which are consumed the deleterious matters and gases which stagnant water ge- nerally contains ; \vrhile, like all green plants, they pour into the atmosphere, during sunshine, oxygen prepared in their delicate tissues from the carbonic acid on which they feed. Comparatively few of them minister to our personal wants, with the exception of a few Ulvse which are used for food, and some of the Confervae which have been employed, where other bandages were unprocurable, for binding frac- tured limbs, &c. SYNOPSIS OF THE ORDERS. 14. SIPHONACE.E. Cells filiform (usually of great length), simple, or branched, variously connected ; either one cell forming a filiform frond ; or several intertwined and anastomosing cells, forming a compound frond. 15. CONFERVACE.E. Cells cylindrical (not of great length), truncate, connected into simple or branching, rarely anastomosing filaments. Filaments naked, or sur- rounded by gelatine. 16. ULVACE^E. Cells many-sided, cohering into a mem- branaceous, rarely gelatinous, flat or tubular frond. 17. OSCILLATORIACE^E. Cells filiform, very long, simple, naked, or invested with mucus, or compacted to- gether into a firmly gelatinous frond. Endochrome annulated. 18. NOSTOCHACE^E. Cells elliptical or globose, connected in gelatinous, moniliform strings. Filaments sepa- rate, or several united together in a gelatinous frond. 19. (PALMELLACE^E) : Sub-order Hormosporea. Cells el- liptical or globose, separate, contained within mem- branaceous, tubular filaments. SIPHONACE^E. 191 ORDER XIV. SIPHONACEJ5. Siphoneae, Grev. Alg. Brit. p. 183. J. Ag. Alg. Medit. p. 17. Endl. 3rd SuppL p. 16. Due. Class, p. 32 (also Halymedeae and Acetabularieae). Siphoneae, Lindl. Veg. Kingd. p. 18, and Vaucherieae (in part), p. 22. Vauchevieae, Codieas, Anadyonieneae, Polyphyseae and Dasycladeae, Kiltz. Phyc. Gen. pp. 302, 308, 311, 312. Caulerpeae, Grev. et Auct. (?) DIAGNOSIS. — Green, marine or fresh-water Algae, composed of continuous, tubular, simple or branched filaments, free or variously combined in cylindrical or expanded fronds. NATURAL CHARACTER. — Root, where obvious, consisting of a mass of fibrous threads interwoven together or entangled ; rarely of different character from the threads constituting other parts of the frond. Frond in the simplest genera ( Vau- cheria, Bryopsis) consisting of a single, very long, branching cell or membranous tube, filled with granular colouring mat- ter, without any partition or dissepiment from the base to the apex of the branches. Thus, if a whole frond of Bryopsis plumosa be placed on a piece of glass, under water, and the tip of one of its branches be wounded, the contents of the frond may be pressed out through the lacerated part, leaving nothing but an empty skin, and showing that there is no in- ternal diaphragm in any part of the tube. This filiform cha- racter of the cells distinguishes the genuine members of the order, the more compound among which are made up of thread-like cells, resembling those of Bryopsis, variously united together. In Vaucheria the threads remain separate, but are densely tufted together, and variously interwoven, so as, in many instances, to form spongy, cushion-like tufts. In Codium there is a closer connexion, the tips of the threads lying close together, or slightly cohering, and the filaments disposed in a definite order, so as to form fronds with a de- termined outline. In Halimeda the union is still more inti- mate, the spaces between the tips of the filaments being closed up by carbonate of lime, and thus the frond cased in a sort of epidermis, and all its parts built up into a common structure. If a piece of Halimeda be placed in acid, so as to dissolve the lime, its parts may readily be dissected, and it will then be seen to consist of branching cells, resembling those of a Codium or Bryopsis. 192 SIPHONACE^K. Besides the colouring matter or endochrome dispersed through the plant, and which forms in part the fructification, many plants of this order are furnished with little bodies called coniocystte, through which the species is reproduced. These bodies are formed at the sides of the cells, and at first manifest themselves as small mamillae, or tubercular or club- shaped ramuli, containing a denser colouring matter than other parts of the frond. A diaphragm is formed at their base, and thus a cell is enclosed, in which the colouring matter becomes further organized and gradually compacted into a sporangium. In some Vaucherics (as in V. clavata] a portion of endochrome at the apex of a branch swells, be- comes dense, and at length consolidated and separated from that beneath it by a diaphragm. Thus a propagulum or gemmule is formed, which, at maturity, separates from the frond, and becomes a reproductive body. It is clothed with vibratile cilia, by which it moves about until it has fixed it- self, and then, lengthening at each end, it changes into a filament, which gradually assumes the character proper to the species, and becomes a new individual. Coniocysta may commonly be found on Vaucheria in spring, and on the filaments of Codium lament osum in summer, but have, hitherto, been only noticed in one species of Bryopsis. The plants of this order are widely dispersed. All our ge- nera are cosmopolitan, and Codium tomentosum is as com- mon on the shores of the Pacific, from high northern to high southern latitudes, as it is in the Atlantic and Mediterranean. A large number of genera are peculiar to warmer parts of the sea, some of them among the most elegant of all marine plants. Among these are Acetabularia, a Mediterranean and West Indian genus, with thread-like stems crowned with a papery cup (composed of filaments united together) fringed with byssoid ramuli like those of a Bryopsis ; and Anadyo- mene, a native of the same seas, having expanded fronds like those of an Ulva, composed of tubular cells arranged in starry patterns. If Caulerpa belong, as I have always thought — an opinion not shared by all my fellow-students, and therefore to be reconsidered — to this order, a very re- markable tropical and subtropical genus should be mention- ed, which carries the type of structure peculiar to these plants to its highest pitch. That genus contains numerous species, distinguished among Algae as rising from prostrate, rooting stems, that form a compact mat, and serve to bind together the loose sands on which they grow. They are CODIUM. 193 therefore deserving of being spoken of among the pioneers of civilization, which prepare a resting place for colonies of other plants and animals. In Brongniart's ' History of Fossil Vegetables ' a fossil is figured (PL 9 bis, Jig. 1) under the name Fucoides hypnoides, which bears a very close resem- blance to Caulerpa hypnoides, a. recent species from New Hol- land; and several other fossils, which appear to be the remains of species of Caulerpa, are known to palaeontologists. SYNOPSIS OF THE BRITISH (MARINE) GENERA. I. CODIUM. Filaments closely combined into a sponge- like frond. [Plate 24, A.] II. BRYOPSIS. Filaments free, pinnately branched. [Plate 24, B.] III. VAUCHERIA. Filaments free, irregularly branched. [Plate 24, C.] I. CODITJM. Stackh. [Plate 24, A.] Frond spongy, dark green (crustaceous, globular, cylindri- cal or flat), composed of an interwoven mass of tubular, con- tinuous filaments. Fructification : opaque vesicles attached to the filaments, near the surface of the frond. Grev. — Name, fco&ov, the skin of an animal ; from the soft substance. 1. C. Bursa, L. ; frond spherical, hollow. Grev. Ala. Brit. p. 186; Hook. Br. Fl. ii. p. 318. Fucus Bursa, E. Bot. t. 2183. On rocks iu the sea, very rare. Perennial ? Summer. " Coast of Sus- sex, plentifully, Pallas;" Turner. Shores of Cornwall, Mr. Rashleigh. Near Torquay, Mrs. Griffiths. Belfast, Mr. Templeton. — Frond a globu- lar, spongy, hollow ball, 1 — 8 inches in diameter. Structure similar to the preceding. 2. C. adhaerens, Ag. ; frond forming a velvety crust on the surface of rocks. Harv. in Hook. Journ. Bot. p. 305 ; Wyatt, Ala. Damn. No. 127; Harv. Phyc. Brit. t. xxxv. A. On rocks in the sea, near low-water mark ; very rare. Annual? At Torquay, Mrs. Griffiths. Land's End, Mr. Ralfs. Gorran Haven, &c., Mr. Peach. Falmouth Harbour, Miss Warren. Bathlin Island, Antrim, Mr. Moore. Tory Island, Mr. Hyndman. — Spreading over the rock in irregular patches of two feet or more in extent, resembling " fragments of beautiful green velvet." Substance gelatinous, dense, closely adhering to paper. Mrs. Griffiths, who has watched this plant from its first appear- O 194 BRYOPSIS. ance till it had considerably extended itself, remarks, " that it does not show the least tendency to throw up a frond. It has an uneven surface, from taking the fonn of the rock, or even roots of coarse weeds, over which it crosses.'' She considers it a true species. 3. C. amphibium, Moore ; fronds minute, erect, cylindri- cal, simple, obtuse, aggregated in widely-spreading strata. Moore and Harv. An. Nat. Hist. xiii. p. 321 ; Harv. Phyc. Brit. t. xxxv. B. Turf banks, near high-water mark, but washed by every tide, at Round- stone, and at the head of Birtirbui Bay, Galway, Mr. Wm. M'Calla.— Tufts widely spreading, the bases composed of entangled fibres, among which rise numerous mamillaeform fronds, from a quarter of an inch to an inch in height, usually simple, rarely emarginate or forked ; having exactly the structure of the frond of C. tomentosum. It differs from the young of that species not merely in habitat, but also in having the fronds densely tufted together, not solitary or dispersed. The colour is a herbaceous green, and the substance soft. 4. C. tomentosum, Huds. ; frond cylindrical, dichotomous. Grev. Alg. Brit. p. 185, t. 19; Hook. Br. Fl. ii. p. 318; Wyatt, Alg. Damn. No. 35; Harv. Phyc. Brit. t. xciii. Fucus tomentosus, E. Bot. t. 712. On rocks in the sea ; frequent. Perennial. Summer. — Frond rising from a spreading spongy base, cylindrical, from a quarter to nearly half an inch in diameter, 6 — 12 inches long, more or less regularly divided in a dichotomous manner ; sometimes regularly dichotomous ; sometimes pal- mato-partite, the segments forked; sometimes beset with short lateral branches. Structure filamentous, the centre composed of longitudinal, in- terlaced, colourless fibres, the circumference of radiating, horizontal, club- shaped, deep green filaments, invested by a viscid gelatine. Fructification : dark green ovate vesicles, borne by the club-shaped filaments. II. BRYOPSIS. Lamour. [Plate 24, B.] Frond membranaceous, filiform, tubular, cylindrical, glis- tening, branched; the branches imbricated, or distichous and pinnated, filled with a fine green, minutely granuliferous fluid. Grev. — Name, @puov, a moss, and u^is, an appearance. 1. B. plumosa, Huds.; frond filiform, branched, naked below, the branches scattered, spreading, twice or thrice pinnated, the pinnae pectinated. Grev. Alg. Brit. p. 187, t. 19 ; Hook. Br. Fl. ii. p. 318 ; Wyatt, Alg. Damn. No. 128 ; Harv. Phyc. Brit. t. iii. Ulva plumosa, E. Bot. t. 2375. On rocks, &c., in tide-pools. Annual. Summer and autumn. — Frond 1 — 4 inches high, more or less branched, sometimes with a nearly simple stem, set with numerous close branches ; at other times much divided in a subdicholomous or irregular manner. Branches naked at base, in the upper part closely pinnated with subopposite, slender, distichous or rarely VAUCHERIA. 195 irregular ramuli, which gradually diminish in length to the apex. Colour a fine deep green. Substance lubricous and adhering to paper. A beau- tiful plant, whose branches resemble beautiful, glossy, bright green feathers. 2. B. hypnoides, Lamour. ; frond slender, very much branched ; the branches long ; the ramuli capillary, irregu- larly inserted, somewhat erect, the lower ones elongated. Grev.—Hook. Br. Fl. ii. p. 318; Wyatt, Alg. Danm. No. 81 ; Harv. Phyc. Brit. t. cxix. On rocks and stones in tide-pools, and on the larger Algae, rather rare. Southerness, Kirkcudbright, Sir W. Jardine, Bart. Frith of Forth, Mr. Hassell. Appiu, Capt. Carmichael. Torquay, Mrs. Griffiths. Portrush, north of Ireland, Mr. D. Moore. Roundstoue, Mr. M'Calla. — Frond 2 — 4 inches high, much branched, the branches repeatedly divided in an alternate or irregular manner ; lesser branches set with irregularly scat- tered, somewhat pinnate, more or less dense ramuli. Colour a fine yellow green. This is a more slender, very much more branched plant than the preceding, and the rarnuli are irregularly scattered, sometimes issuing from all sides of the filaments. III. VAUCHERIA. De Cand. [Plate 24, C.] Fronds aggregated, tubular, continuous, capillary, coloured by an internal, green, pulverulent mass. Fructification : dark green, homogeneous sporangia ( coniocysta) , attached to the frond. Grev. — Named in honour of M. Vaucher, a dis- tinguished writer on fresh- water Conferva. (The species are natives of fresh water, with the following (British) exceptions). 1. V. submarina, Berk. ; frond capillary, forked, fastigiate; sporangia scattered, ovate or lanceolate, sessile. Berk. Gl. Alg. t. 8. V. dichotoma, @. submarina, Ag. — Hook. Br. FL ii. p. 319. On the muddy sea-shore, rare. Weymouth, Rev. M. J. Berkeley .—Tufts 2 or 3 inches high, not diffused, fastigiate ; filaments much more slender than in V. dichotoma, less branched, the branches more irregular. Vesicles numerous, scattered over the upper branches. 2. V. marina, Lyngb. ; filaments loosely tufted or distinct, branches few, very long, obtuse ; sporangia solitary, obovate, pedicellate, lateral. Carm—Hook. I. c. p. 319 ; Lynyb. t. 22 ; Wyatt, Alg. Danm. No. 168. In the sea. Annual. Summer. Parasitical on Furcellaria lumbricalis, Appin, Capt. Carmichael. On mud at Torbay and Salcombe, Mrs. Grif- fiths and Mrs. Wyatt. — Fronds tufted or somewhat spreading, erect, very slender and flaccid, irregularly branched, somewhat forked ; the branches erect. Vesicles few, scattered, broadly obovate and very obtuse, by which character it is easily distinguished from V. submarina, subpedicellate. Co- lour-bright green, becoming rather brownish, but retaining a gloss in drying. Mrs. Griffiths has kindly presented me with specimens in fructification. o 2 196 CONFERVACE^E. 3. V. velutina, Ag. ; filaments creeping ; branches fastigi- ate, woven into a velvety stratum ; sporangia solitary, globose, lateral. Carm. — Hook. 1. c. p. 319. On the muddy sea-shore, flooded by the tide. Annual. Spring and sum- mer. Appin, Capt. Carmichael. Miltowu Malbay. — " Filaments exceed- ingly tough, interwoven into a dense, velvety, green stratum, pellucid below and creeping over the mud ; branches near the extremity erect, fas- tigiate, and more or less crooked. Vesicles solitary, globular, on short lateral peduncles." Carm. ORDER XV. CONFERVACE.E. Conferveae, J. Ag. Alg. Medit. p. 12. Harv. Man. Ed. I, p. 124. Lindl. Veg. Kingd. p. 18. Confervoideae, Endl. 3rd Suppl. p. 14. DIAGNOSIS. — Green, marine or fresh-water Algse, composed of articulated threads or filaments, simple or branched, free or surrounded by gelatine. Cells cylindrical, truncated. NATURAL CHARACTER. — Root rarely more than a point of attachment, and often perishing on the maturity of the frond. Frond in all cases composed of cylindrical, truncated cells of moderate length, strung together in filaments, of which they are the articulations. These filaments sometimes anas- tomose, so as to form a net (as in Hydrodictyon] ; some- times at maturity two separate filaments approach each other, when a species of anastomosis takes place between them, a cell in one filament becoming connected to a cell in another filament by means of a membranous tube, through which the contents of one are discharged either into the other, or else lodged in the connecting tube ; in both cases forming the nucleus of the fructification. This mode of connexion, which is called conjugation, is characteristic of the sub-order Zygnemea. In most cases, however, and in all the genuine Confervea, the filaments are free one from another, either simple or variously branched ; the ramification is frequently alternate, or secund, rarely dichotomous, and rarely opposite. In the sub-order Chtetophorete each frond consists of several filaments combined together in a more or less perfect manner by surrounding gelatine, and frequently terminating in hair- like cellules of extraordinary length and tenuity ; whilst in other species of this sub-order each cell is furnished with a very long rigid seta, and this is remarkably obvious in Ochlo- chcete, the only one of this sub-order which our limits admit. CONFERVACE^E. 197 The mode by which the frond lengthens is twofold. Either new cells are continually emitted, as buds, from the apices of the last formed cells ; or else the old cells continually di- vide in the centre. In the first case the frond continues to lengthen by constant additions to its points, and this is truly acrogenous ; in the other it grows equally throughout its whole length. This latter mode of increase is most frequent among the species with simple filaments. The fructification either consists of zoospores formed out of the colouring matter of the cells, and emitted through an aperture formed in the cell-wall ; or else the whole mass of endochrome contained in a cell, and often the whole contents of two cells are con- centrated into a. sporangium or conceptacle, which is deposited in the water on the perishing of the frond. In the Confervea this sporangium is usually formed out of the contents of a sin- gle cell, but is not always lodged in the cell in which it ori- ginates; for in one genus (Tiresias) supplementary cells, are formed at one extremity of the cell furnishing the sporaceous matter, and in these the sporangium is lodged. In the Zyg- nemeac the matter of two cells constantly goes to form the sporangium. This matter either collects in one of the cells, leaving the other quite empty ; or else is deposited in a sup- plementary cell formed in the connecting tube ; or (as in Staurocarpus), where the two cells inosculate without any tube between them, the sporangium, taking the form of a cross, lies partly in one cell and partly in the other. In the Chce- tophoreae the sporangia are lateral and external, developed as buds from the cells of the filament, or they are the enlarged cells of the ramuli. By far the larger number of the Confervaceae inhabit fresh water, and are found in all parts of the world wherever water lies stagnant, and wherever it flows. The bright green, glossy threads that float on the surface of ponds and ditches are commonly species of the sub-order Zygnemete, a highly curious and beautiful family, of which there is no marine ex- ample. When young the filaments lie at the bottom of the pool, but as they approach maturity they float to the surface, where they often lie so thickly as to retain within their meshes large bubbles of air, which they have disengaged during the progress of vegetation, and which is in great part oxygen. When shallow water lies for some weeks in sum- mer on the surface of flat land, it often becomes completely filled with the threads of these plants, which by their vege- 198 CLADOPHORA. tation counteract the evil effects which the decay of other vegetables under the water would otherwise dispense, and on the clearing off of the water their relics quickly dry up, without undergoing decomposition. In this case the matted threads are soon bleached white in the sun, and form a sort of natural paper. By the older practitioners several of the Confervas were used in binding up broken limbs, a purpose for which they were well adapted from their softness and power of retaining moisture ; but this was before the days of oil-skin and gutta percha. SYNOPSIS OF THE BRITISH (MARINE) GENERA. Sub-order 1. CONFERVE^E. Filaments free, not surrounded by gelatine. Sporangia contained in the articulations. J. CLADOPHORA. Filaments tufted, much branched. [Plate 24, D.] II. RmzocLo;s7iUM. Filaments decumbent, with root-like branches. [Plate 24, F.] III. CONFERVA. Filaments unbranched. [Plate 24, E.] Sub-order 2. CH^ETOPHORE^E. Filaments united in sub- membranaceous or gelatinous fronds ; cells often tipped with bristles. Sporangia external. IV. OCHLOCH^LTE. Frond disciform. Filaments radiat- ing from a central point, prostrate, irregularly branch- ed ; each cell produced above into a rigid, inarticu- late bristle. [Plate 25, E.] Sub-order I. CONFERVE.E. I. CLADOPHORA. Kuiz. [Plate 24, D.] Filaments green, attached, uniform, branched, composed of a single series of cells or articulations. Fruity aggregated granules or zoospores, contained in the articulations, having, at some period, a proper ciliary motion. — Name, from ;<;Xa5bj, a branch^ and Qopeu, to bear. Much branched, tufted plants, CLADOPHORA. 1 99 chiefly marine. A few, here omitted, inhabit clear, fresh- water streams. 1. C. Brou'nii, Dillw. ; filaments forming dense, cushion- like tufts, erect, rigid, flexuous, elastic, slightly branched ; branches few, long, sub-simple, secund ; axils acute, articu- lations 4 or 5 times longer than broad, the lower ones thick- ened upwards, the upper cylindrical. Harv. I. c. p. 356 ; Dillw. Suppl. t. D. ; E. Sot. t. 2879 ; Harv. Phyc. Brit. t. xxx.; Wyatt, Alg. Danm. No. 225. C. pulvinata, Brown, MS. On wet rocks in a cave near Dunree, North of Ireland, R. Brown, Esq. On shady rocks at the entrance of a small cave beyond Black Castle, Wick- low, where it is exposed to the dripping of fresh water, and the occasional overflow of the sea. Cornwall Coast, near Land's End, Mr. Ralfs. — This forms exceedingly dense, very rigid, tufts, of a black-green colour when growing, but, on having the water expressed, and being held to the light, exhibits a beautiful yellow-green tint. Filaments so matted together that it is difficult to separate a single thread. They appear to originate in a mass of creeping, branched, densely matted fibres, which form the base of the tufts. They are erect, from half an inch to an inch high, flexuous, very rigid and elastic ; the branches few and nearly simple, almost always secund, very erect. A very curious and distinct plant, having, to the naked eye, a good deal the appearance of Vaucheria terrestris, but totally differ- ent in structure. It is perhaps allied to C. (egagropila. I have examined a specimen from Mr. Brown in the late Mr. Templetoris herbarium, and find it agree in every respect with my Wicklow plant. 2. C. repensy J. Ag. ; forming dense, cushion-shaped or globular tufts ; filaments short, capillary, rigid, densely mat- ted together, rising from root-like fibres, slightly branched ; branches erect, sub-simple, or forked, naked, or with a few distant, secund ramuli; articulations cylindrical, very long, (ten to twenty times as long as their diameter). Harv. Phyc. Brit. t. ccxxxvi. Thrown on shore after a gale. Annual? Summer. Jersey, very rare, Miss Turner. — Tufts an inch or two in diameter, and about half an inch thick, composed of innumerable, slender filaments densely matted together. The habit is very similar to that of C. firownii, but the articulations are of much greater length, and of a different form. This species is also a native of the north coast of France, and of the Mediterranean sea. 3. C. pellucida, Huds. ; filaments cartilaginous, rigid, erect, bright green ; di-trichotomous, the axils very acute, branches erect; articulations many times longer than broad. Harv. 1. c. p. 357 ; Wyatt, Alg. Danm. No. 193 ; E. Bot. t. 1716; Harv. Phyc. Brit. t. clxxiv. On rocks near low-water mark. Yarmouth, Sir W. J. Hooker. South of England. Several places in Ireland ; very fine in Belfast Lough, Mr. 200 CLADOPHORA. Thompson. — Root a mass of fibres. Filaments 4 — 6 inches high, setaceous, extremely rigid, tough and wiry, tufted or subsolitary, rising with an undi- vided stem for half an inch to an inch, then forked or trifurcate, and after- wards repeatedly branched in a di-trichotomous or somewhat umbellate manner, the uppermost branches more or less furnished with di-trichoto- mous or tufted ramuli. Joints of the stem and branches very long, the dis- sepiments rarely occurring except at the divisions of the branches ; in the ramuli short, 3 or 4 times longer than broad. Colour a fine, glossy, trans- parent green, fading much in drying. It scarcely adheres to paper. 4. C. rectangular is, Griff. ; filaments setaceous, rigid, ir- regularly branched ; branches distant, patent, set with short, opposite, horizontal ramuli ; articulations twice or thrice as long as broad. Harv. in Hook. Br. Fl. ii. Addenda, p. 10; Wyatt, Alg. Damn. No. 145 ; Harv. Phyc. Brit. t. xii. In the sea, thrown up ; very rare. Summer. Torquay, Mr. Borrer and Mrs. Griffiths. Roundstone, Mr. M'Calla. Arran, Galway, Mr. Andrews. — Filaments as thick as horse-hair, 8 — 12 inches long, divided in an irregu- lar manner into a few principal branches ; branches patent, more or less furnished with subdistant, horizontal, opposite ramuli, from a line to an inch in length, and either simple or bearing a second series ; very rarely, by abortion, they are alternate. Colour a full green, fading in the herbarium. Substance rigid, very imperfectly adhering to paper. Joints uniform throughout the plant, generally 2 or 3 times longer than broad. One of the most beautiful and distinct, as it is the rarest, of the genus. 5. C. Macallana, Harv. ; filaments setaceous, rigid, full green, very flexuous, loosely bundled together, excessively branched ; branches alternate, or rarely opposite, zigzag, very patent; ramuli short, recurved, simple or pectinated, obtuse; articulations twice or thrice as long as broad; en- dochrome rather dense. Harv. Phyc. Brit. t. Ixxxiv. On the sandy bottom of the sea, in 4 — 10 fathom water. Annual. Summer. Dredged in Roundstone Bay, abundantly, Mr. Wm.M'Calla. — Filaments forming crisped, sub-cylindrical, loose bundles 6 — 20 inches long, bristling when removed from the water, of a rich grass-green, much branched and inextricably entangled, rigid. Branches very flexuous, irre- gular in length and insertion, more or less clothed with very patent ramuli. This has much of the outer habit of C. rectangularis, mixed with which it often occurs at Eoundstone, but may at once be known by the secund or alternate ramuli. It is named in honour of its discoverer, the late Mr. Wm. M'Calla, a most successful and acute explorer of Roundstone and the neighbouring bays — who added many new species to the Fauna and Flora of Ireland, and whose early death is much to be regretted. Mr. M'Calla fell a victim to the cholera in the spring of the present year, (May, 1849). 6. C. Hutchinsite. Dillw. ; filaments setaceous, cartilagi- nous, rigid, glaucous green, flexuous, tufted, bristly ; ramuli curved, simple or furnished on the interior face with processes CLADOPHORA. 201 of one articulation ; articulations twice as long as broad, joints contracted. Dillw. t. 109 ; Hare. 1. c. p. '357 ; Wyatt, Alg. Damn. No. 226 ; Harv. Phyc. Brit. t. cxxiv. On rocks, &c., near low-water mark ; rather rare. Bantry Bay, Miss Hutchins, and various stations on the English and Irish coasts. — Fila- ments thicker than horse-hair, 6 — 8 inches long, flexuous, repeatedly di- vided in an alternate manner; branches rather distant, spreading or divari- cated, more or less furnished with short branchlets, having a few short, secund ramuli along their upper faces. Colour deep glaucous green, "with changeable tints when fresh, and under water appearing almost white,'' (Miss Hutchins). Substance rigid and tough, more or less perfectly adher- ing to paper. Joints uniform throughout the plant. Nearest C. pellucida in texture, and C. diffusa in habit and character: from the latter it is not always easy clearly to distinguish it. 7. C. diffusa, Roth ; filaments sub-setaceous, rigid, dark or full green, flexuous, much branched ; branches distant, elongated, furnished towards the top with a few short, patent, secund ramuli ; articulations 3 or 4 times longer than broad. Dillw. t. 21 ; E. Bot. t. 2289 ; Harv. I. c. p. 358 ; Wyatt, Alg. Danm. No. 144 ; Harv. Phyc. Brit. t. cxxx. On rocks, &c. in the sea, not uncommon. Southern shores of England and Ireland : West of Ireland. Port Rush, Mr. Moore. — Filaments 6 — 10 inches long, as thick as horse-hair, loosely tufted, generally so rigid as to bristle out when removed from the water, but occasionally flaccid, very flex- uous, distantly branched ; branches alternate, much divided, either bare of ramuli, or furnished toward the end, or sometimes generally, with short, secund branchlets. Joints 3 or 4 times longer than broad, nearly uniform in all parts of the frond. Colour either grass-green or dark green. 8. C. nuda, Harv. ; filaments sub-rigid, slender, very straight, dull green or olivaceous (when dry), sparingly dt- chotomous ; ramuli few and scattered, appressed, the upper- most often opposite ; articulations many times longer than broad. Harv. in Mack. Fl. Hib. in. p. 229. On basalt rocks, in the sea. Portstewart, Mr. D. Moore. — Filaments loosely tufted, 2 or 3 inches high, sparingly branched, very straight, set with a few, scattered, very erect and appressed ramuli, the uppermost ones often opposite, which makes the apices of the branches appear three-forked. Articulations very long. This differs from any species with which I am acquainted, but may, perhaps, be the C. aspera of Agardh, which in the ' British Flora ' I have doubtfully referred to C. nigricans. To avoid con- fusion, I think it better to give a new name to our present plant. In the straight filaments and erect ramuli it resembles C. rupestris, but differs in colour and in the great length of the joints. Perhaps it may be only a va- riety of the latter. (A doubtful species— 1 849). 9. C. rupestris, Linn. ; filaments slender, rigid, dark green, straight, tufted, bushy ; branches erect, crowded, 202 CLADOPHORA. densely clothed with appressed ramuli ; articulations 3 or 4 times longer than broad. Dillw. t. 23; E. Bot. t. 1699; Harv. 1. c. p. 357 ; Wyatt, Alg. Danm. No. 95 ; Hare. Phyc. Brit. t. clxxx. On rocks in the sea, about half-tide level, very common. — Tufts 3 — 6 inches long, very dark or blackish green. Filaments rigid, densely and closely branched, thickly clothed with very erect or appressed ramuli, scarcely adhering to paper. 10. C. l&tevirens, Dillw. ; filaments much branched, bushy, forming fine tufts of a transparent yellow-green colour, gray- ish and without gloss when dry ; branches erecto-patent, crowded, repeatedly divided ; ultimate ramuli secund ; joints of the chief divisions long, of the ramuli about thrice as long as broad. Dillw. t. 48 ; E. Bot. t. 1854. C. glomerata, 0. marina, Ag. — Harv. in Hook. Br. Fl. ii. p. 357 ; Wyatt, Alg. Damn. No. 143; Harv. Phyc. Brit. t. clxxxix. On rocks, stones and Algse, in tide-pools, very common. — Tufts 4 — 8 inches long. Except in its marine habitat, I cannot distinguish this from C. glomerata, with which Agardh unites it, as it appears to me, justly. Mrs. Griffiths, however, than whom no one has studied this genus more carefully, is of a different opinion, and to her judgment T yield. 11. C. Jlexuosa, Dillw. ; filaments very flexuous or angu- larly bent, jointed, often sub-opake, rather rigid, dull green, but slightly branched ; branches variable in number and length, more or less divided, furnished with long, patent branchlets, whose inner edge is pectinated with a few secund ramuli; articulations thrice as long as broad. Dillw. t. 10 ; E. Bot. t. 1944. Conf. fracta, &. flexuosa, Ag. — Harv. in Hook. I. c. p. 356 ; Wyatt, Alg. Danm. No. 227. In salt-water ditches near Yarmouth, D. Turner, Esq. In the sea, not uncommon. Torquay, Mrs. Griffiths. Ballycaslle, Miss Hincks. Seve- ral other parts of the east coast of Ireland. — Filaments 4 — 8 inches long, remarkably flexuous, rather harsh to the feel. This really seems distinct from C. fracta, habitat out of the question ; but I suspect that more than one species is confounded under this name. 12. C. gracilis, Griff. ; filaments capillary, flexuous, silky, much branched, bright yellow-green ; main branches entan- gled, sparingly divided, angulato-flexuous ; ultimate ramuli pectinato-secund, much attenuated, straight and very long ; articulations about 3 — 5 times longer than broad. Griff', in Wyatt, Alg. Danm. No. 97; Harv. Fl. Hib. iii. p. 230; Harv. Phyc. Brit. t. xviii. In deep water, on rocks and Algze. Torquay, Mrs. Griffiths. Youghal, Miss Ball. Belfast Bay, and at Ballantrae, Ayrshire, Mr. W. Thompson. CLADOPHORA. 203 — Filaments forming soft, silky tufts, 6 — 12 inches long, with something of a main stem, from which spring very numerous, long, and more or less di- vided, very flexuous or angularly twisted branches, plentifully clothed with elongated, pectinate, secund branchlets, of which the ultimate ramuli are very long, slender, and straight or slightly curved. Colour a fine, rich, yel- low-green, somewhat faded in the herbarium, but preserving a silky gloss. Substance soft, imperfectly adhering to paper. Nearly allied in character to C.Jlexuosa, but with a very different habit. 13. C. Rudolphiana, Ag. ; filaments very long, exceed- ingly slender, flexuous, subgelatinoso-tnembranaceous, much branched, yellow-green, inextricable ; branches di-ti'ichoto- mous or irregular ; ultimate ramuli pectinate, secund, very long and much attenuated ; articulations of the main fila- ments many times longer than broad, here and there swollen, their granular endochrome somewhat spiral ; those of the ra- muli 6 — 10 times as long as broad. Harv. Phyc. Brit. t. Ixxxvi. C. Katieana, M'Calla, Alg. Hib. No. 29. Parasitical on Zostera, and various Laminaria, and other Algae, in 2 — 6 fathom water. Annual. Summer. Very abundant in Roundstone Bay, Connernara, Mr. W. M'Calla. Falmouth, Miss Warren. — Filaments 6 — 20 inches long, exceedingly slender and soft, forming beautifully silky, bright green, sub-gelatinous tufts. A much more slender plant than C. gra- cilis, with longer joints and more attenuated ramuli. 14. C. refracta, Ag. ; filaments capillary, sub-rigid, tufted, bright green, very much branched; secondary branches spreading on all sides, repeatedly divided, thickly clothed with very patent or reflexed, short branchlets, which are pec- tinated with ramuli on their upper surface. Wyatt, Alg. Damn. No. 228 ; Harv. Phyc. Brit. t. xxiv. In the sea ; in rocky pools left by the tide. Dunlecky Castle, Kilkee. Ilfracombe, Mrs. Griffiths. Mangan's Bay, Co. Cork, Miss Ball. Giant's Causeway, Mr. W. Thompson. — Filaments 3 or 4 inches long, slender, tufted ; the main stems somewhat woven together or ropy, the secondary branches free, spreading on all sides aud much divided ; the ultimate branch- lets very patent or reflexed, pectinato-secund, opposite or alternate. Colour a brilliant yellowish green, which is partially preserved in a dry state. Sub. stance rather rigid, imperfectly adhering to paper. This beautiful plant is nearly allied to C. albida, but the filaments are coarser and far more rigid, the ultimate branches shorter and more patent, often strongly reflexed, and the habit by no means spongy. 15. C. albida, Huds. ; filaments exceedingly slender, flac- cid, pale yellow green (whitish when dry), forming dense, silky, or somewhat spongy, intricate tufts ; branches crowded, irregular, the uppermost patent and mostly opposite; ramuli opposite or secund ; articulations 4 or 5 times longer than 204 CLADOPHORA. broad. E. Bot. t. 2327 ; Harv. L c. p. 358 ; Wyatt, Alg. Damn. No. 96 ; Harv. Phyc. Brit. t. ccxxxv. On rocks and the larger Algae in the sea, below half-tide level ; frequent. — Tufts 2 — 6 inches long, pale green, exceedingly dense or spongy, flaccid. Filaments extremely slender, excessively and intricately branched ; the branches very irregular : ultimate ramuli short, patent, opposite or secund, issuing from almost every joint, and occasionally bearing a second set. In the herbarium it fades to a pale yellowish, wholly without gloss, by which character it is best marked from its allies. Joints short. Mrs. Griffiths finds a beautiful plant at Torquay, having many characters in common with C. albida,'but 12 inches long and of a bright yellow-green colour, which is partially preserved in drying. For the present I regard it as a variety of this species. 16. C. lanosa, Roth ; filaments slender, short, yellow- green, forming dense tufts ; branches virgate, erect, sub-dis- tant, straight, alternate or opposite, with a few alternate or secund ramuli, axils very acute ; lower articulations twice, upper six times longer than broad. E. Bot. t. 2099 ; Harv. L c. p. 358; Wyatt, Alg. Danm. No. 194; Harv. Phyc. Brit. t. vi. In the sea, on rocks or, more frequently, on the larger Fuci. — Filaments forming small, entangled, woolly tufts, an inch long, pale green, stoloni- ferous below, branches straight and erect, all the axils very acute. In a dry state it is wholly without gloss, faded, except near the tips, where it generally preserves a glaucous green colour. 17. C. uncialis, Fl. Dan. ; tufts very short, spongy, sim- ple below, above divided into numerous fastigiate, woolly segments ; filaments flexuous, sparingly branched, densely interwoven ; ramuli distant, secund, somewhat pectinate, long, patent or incurved ; articulations 2 — 4 times longer than broad. Ag. Syst. Alg. p. Ill ; Fl. Dan. t. 771, /. 1 ; Harv. in Hook. Journ. Bot. p. 304 ; Wyatt, Alg. Danm. No. 146 ; Harv. Phyc. Brit. t. ccvii. On rocks near low-water mark. Torquay, Mrs. Griffiths. New Castle, coast of Down, Mr. W. Thompson. Katblin, Antrim, Mr. D. Moore. Common at Balbriggan. — Tufts an inch high, dark green, spongy, with something the habit of Ectocarpus tomentosus, composed of slender, irre- gularly branched filaments, densely entangled. Certainly nearly allied to the preceding, with some states of which it may, without careful examina- tion, be confounded. 18. C. arcta, Dillw. ; filaments forming broad, somewhat starry tufts, of a full green colour, much branched ; branches straight, crowded, erect ; ramuli sub-appressed, opposite or alternate ; articulations either uniformly twice as long as broad, or with the lower joints short, the upper very long. CLADOPHORA. 205 Dillw. t. E. ; E. Bot. t. 2098 ; Har-v. 1. c. p. 359. C. centra- Its, Lyngb., Harv. I. c. p. 358 ; Wyatt, Alg. Danrn. No. 46; Harv. Phyc. Brit. t. cxxxv. On rocks in the sea, generally above half-tide level, frequent. — Tufts rising from a broad disk formed of dense fibres. Filaments spreading in a circle, fastigiate, much branched : in the young specimens the branches are somewhat separate, all remarkably erect or straight (when it is C. arcta of Dillwyn and of ' Brit. Flora,' and in a still younger state C. vaucheria- formis of Agardh) ; in the older they are more or less matted together or interwoven by means of rootlike fibres which issue from the joints of the main branches, the apices only, in these specimens, produced beyond the spongy tuft, long, slender, straight, of irregular length and slightly branch- ed ; all the rarnuli extremely erect and close-pressed (forming the C. cen- tralis of Lyngbye and of ' Brit. Flora'). Joints extremely variable, some- times uniformly twice as long as broad throughout, but more frequently the lower joints are short, those of the upper branches very long. Colour a fine, deep, glaucous green, partially discharged in fresh water or fading in the herbarium. Substance soft and retaining water. Tn the dry state young specimens have a glistening appearance ; old ones, on the contrary, are without gloss, except the young shoots toward the summit, woolly, and considerably faded. In the ' Brit. Flora' I expressed my doubts whether C. arcta and centralis of authors, however dissimilar in their typical states, were really distinct. Since then, numerous specimens in every stage, from the extreme young to the old and battered form, kindly furnished by Mrs. Griffiths, have clearly shown such a giadation of character, that I no longer hesitate to unite them. 19. C. glaucescem, Griff. ; tufts dense, glaucous green, sub-fasti gi ate ; filaments very slender, excessively branched ; branches straight and erect, the lesser ones furnished with close, very erect, straight, elongated ramuli ; joints very short. Wyatt, Alg. Danm. No. 195 ; Harv. Phyc. Brit, t. cxcvi. On rocks, near low-water mark, not uncommon. — Tufts 2 or 3 inches high, dense, somewhat level-topped, of a glaucous green colour. Fila- ments very slender (but more robust than in C. refracla), much branched upwards, the branches straight and erect, the lesser ones furnished with close, very erect and appressed, elongated, straight, setaceous ramuli. Joints thrice as long as broad. Colour preserved in drying. 20. C. falcata, Duby ; densely tufted, dark green ; fila- ments intricate at the base, ultra-capillary, rigid, much curved, irregularly branched ; branches zig-zag, repeatedly divided, the lesser divisions arched, or strongly incurved and falcate, furnished along their inner faces with short, secund, blunt ramuli ; articulations three or four times longer than broad, with a dense endochrome, and pellucid dissepiments. Harv. Phyc. Brit. t. ccxvi. Conf. falcata, Duby, Bot. Gal.— fide Montagne. 206 RHIZOCLONIUM. The bottoms of clear rock-pools, near low-water mark. Annual. Sum- mer. Rocks outside Dingle Harbour, Kerry, W. H. H. Jersey, Miss White. — Filaments densely tufted, 3 or 4 inches long-, thicker than human hair, nearly equal throughout, much branched ; the branches curved and twisted, the lesser divisions and ramuli frequently incurved, arching or strongly hooked inwards ; the whole plant crisp and squarrose. Colour a peculiarly rich, glossy green. Substance rigid, adhering to paper in dry- ing.— I was not aware, at the time I published this plant in Phyc. Brit. that it had already appeared, and oddly enough, under the same specific name, in the Botanicum Gallicon. I am indebted to my friend Dr. Mon- tague for ascertaining the above synonyme of Duby. Species found in brackish water. 21. C. flavescens, Roth; forming pale yellowish strata; filaments slender, sparingly branched; branches alternate or sub-dichotomous, erecto-patent, with scattered, elongate, al- ternate or secund ramuli ; articulations 8 or 9 times longer than broad. Harv. 1. c. p. 356 ; E. Bot. t. 2088 ; Wijatt, Alg. Danm. No. 224. In ditches of brackish or fresh water, not uncommon. — This forms ex- tensive strata of a light yellowish colour, which finally rise to the surface. It is allied to C. fracta, but the filaments are more slender, the joints longer, and the colour is different. It has a silky appearance when dry, and does not adhere to paper. 22. C. fracta, Fl. Dan. ; forming entangled, dull green strata; filaments somewhat rigid, much branched ; branches divaricating; ramuli scattered and very patent; articulations 4—6 times longer than broad. Dillw. Conf. t. 14 ; E. Bot. t. 2338; Harv. I c. p. 356. In ditches, lakes, &c. common. — This forms globose or long entangled tufts, frequently cohering into extensive strata, and finally rising to the surface. The filaments are much and very irregularly branched, all the branches very patent. II. RHIZOCLONIUM. Ktttz. [Plate 24, F.] Filaments green, jointed, uniform, decumbent, simple or spuriously branched ; branches short and root-like. Fruit : granules contained in the cells. — Name, from ptfou, to root, and KXWV, a branch. 1. R. riparia, Roth ; filaments elongated, slender, de- cumbent ; pale green, forming wide strata, flaccid, entangled, angulato-flexuous, slightly branched ; lower branches short, tentacular ; tipper long, sub-simple, with rounded axils ; arti- culations 2 — 4 times longer than broad. E. Bot. t. 2100 ; CONFERVA. 207 Harv. 1. c. p. 359 ; Harv. Phyc. Brit. t. ccxxxviii . Cow/. tortuosa, Wyatt, Alg. Damn. No. 190, (not of Dillw.} On sand-covered rocks, near high-water mark, not uncommon. — Form- ing decumbent, dense strata of some extent. Filaments very slender, with a few root-like branches below, and once or twice branched above. Colour light green, much paler and without gloss when dry. Conf. per- reptans, Carm., is either this species, or a closely allied form. III. CONFERVA. Plin. [Plate 24, E.] Filaments green, attached or floating, unbranched, com- posed of a single series of cells or articulations. Fruit aggregated granules or zoospores, contained in the articula- tions, having, at some period, a proper ciliary motion. — Name, from confer ruminare, to consolidate, because some of the species were used by the ancients for binding up frac- tured limbs. — This genus, notwithstanding the weeding which it has received of late, requires to be still further dismem- bered, when the species shall have been carefully observed at all ages. Generic characters will probably be found in the different manner in which the endochrome is matured, and the manner in which new cells are formed. * Filaments decumbent, stratified, either unattached, or soon becoming so, and at length floating. 1. C. arenicola, Berk.; threads soft, simple, extremely fine, matted, somewhat crisped, at first uniform pale green, at length distinctly jointed; articulations once and a half as long as broad, dotted ; interstices pellucid. Berk. Gl. Alg. t. 13, /. 3. " Creeping on the sandy margins of pools in a salt-marsh periodically flooded, forming a thin, soft, delicate, crisped web, of a pale yellow-green. Threads extremely slender, flexuous, at first self-coloured with a few scat- tered dots, then with manifest dissepiments, and finally the granules con- tract and form a distinctly defined mass of a darker green in the centre, with pellucid interstices. When dry the articulations are slightly con- tracted." Rev. M. J. Berkeley. 2. C. arenosa, Carm.; filaments slender, rigid, interwoven into broad strata ; articulations 3 — 5 times longer than broad. Harv. I. c. p. 353. On the flat sandy shore about half-tide level. Appin, dipt. Carmichael. Bantry Bay, Mr. R. Ball. — " This species occurs in fleeces a yard or more in extent, and of a peculiar structure. They consist of several exceedingly thin layers, placed over each other; but so slightly connected that they may be separated like folds of gauze, to the extent of many inches, without the 208 CONFERVA. least laceration. Filaments 5 or 6 inches long, about the thickness of C. bombycina, rigid, possessed of peculiar roughness ; feeling, when pulled asunder, as if hair were drawn over a piece of rosin. Articulations 3 — 4 times as long as broad ; sporular mass assuming a great variety of forms. When old the filaments become exceedingly rough and often tubercular.7' Carm. 3. C. litorea, Harv. ; filaments thick, rigid, crisped, form- ing loose, extensive bundles of a dull green colour ; articula- tions once and a half as long as broad. C. linum, Harv. in Hook. Br. Fl. ii. p. 352, (not of Roth J. Wyatt, Alg. Damn. No. 220. In salt-water ditches, along the muddy sea shore. — " Forming distinct, loosely interwoven, sub-cylindrical tufts of a yellowish green colour, which, in a more advanced state, changes to a dark olive ; attached at one end, and resting at the bottom of the pool. Filaments as thick as those of C. area, rigid, brittle, and variously curved. Articulations filled with green matter, intermixed with large granules, irregularly contracted and com- pressed in drying." Carm. MS. This plant was called C. Linum in ' Brit. Flora' on the authority of Capt. Carmichael, but that name having now been ascertained to belong to the following species, it becomes necessary to assign a new name to the present one. 4. C. Linum, Roth ; filaments very thick, of great length, deep glossy green, much curled, rigid, forming loosely en- tangled, harsh masses ; articulations as long as broad. C. crassa, Ag.^ Harv. 1. c. p. 352. Conf. capillaris, Dillw. t. 9 ; Harv. Phyc. Brit. t. cl. A. In salt-water ditches, near the coast. Very abundant in the ditches by the North Wall, Dublin. — Filaments many feet long, twice as thick as hogs' bristles, remarkably rigid and fragile when recent, but soon becoming flaccid on exposure to the air. This is the true C. Linum of Roth, see Phyc. Brit. 5. C. sutoria, Berk. ; threads setaceous, extremely long, flexuous, equal, dark green ; articulations once and a half as long as broad; interstices pellucid. Berk. Gl. Alg. t. 14, /. 3 ; Harv. Phyc. Brit. t. cl. B. Floating in ditches and pools subject to the influence of the tide, at Wisbeach, Rev. M. J. Berkeley. April. Near C. Linum and C. crassa, " from both which, however, it differs in being a much more slender plant, and of a closer habit, and by no means variegated." Berk. 6. C. tortuosa, Dillw. ; filaments rigid, slender, much curled and twisted, forming broad, closely interwoven strata ; articulations 2 or 3 limes longer than broad. Harv. I. c. p. 352 ; Dillw. t. 46. In the sea, on rocks and Alga? ; common. — This forms extensive strata, CONFERVA. 209 often several feet in diameter, of a pale or full green colour. |3. is found near high-water mark, and is usually of a duller colour, singularly bent and distorted, and from the angles throwing out tubular, indistinctly joint- ed, partially colourless radicles, " which adhere to particles of sand and other matters within their reach, often to a neighbouring filament." Carm. 7. C. implexa, Dillvv. ; filaments very slender, capillary, rather flaccid, forming extensive, much entangled, bright green strata; articulations rather longer than broad. Harv. 1. c. p. 352 ; Dillw. Suppl. t. B. ; Wyatt, Alg. Damn. No. 142. C. intricate, Grev. Edin. p. 315. Bangia Johnstoni, Grev. in Johnst. Berw. Fl. p. 260. Also C. ulothrix, Lyngb. (of Isted. p. 129). On marine rocks and attached to Algae. Bantry, Miss Hutchins. Ber- wick, Dr. Johnston. Frith of Forth, Dr. Greville. Miltown Malbay. Tor- quay, Mrs Griffiths. — Filaments half as thick as those of C. toriuosa, with shorter joints, forming densely interwoven strata, or little tufts among the branches of other Alga3. Bangia Johnstoni, as Dr. W. Arnott first pointed out to me, differs in no respect from this species. ** Filaments tufted, straight, attached, erect or decumbent (not stratified). 8. C. melagonium, Web. and Mohr; filaments elongate, scattered, straight, thick, erect, stiff and wiry, dark green ; articulations twice as long as broad. Harv. Phyc. Brit. t. xcix. A. ; Harv. 1. c. p. 354 ; Dillw. Conf. Sup. t. B. ; Wyatt, Alg. Danm. No. 221. In the sea, growing on rocks at the extreme verge of low-water mark; found on many parts of the coast, but not common anywhere. — Filaments 5 — 8 inches high, thicker than bristles, scarcely tufted, generally but three or four together or solitary, remarkably rigid and wiry, tenacious and difficult to break ; dissepiments somewhat contracted, very narrow, but pellucid. 9. C. area, Dillw. ; filaments elongated, tufted, straight, harsh, brittle, yellow-green ; articulations as long as broad. Harv. Phyc. Brit. t. xcix. B.; Harv. 1. c. p. 354; JVyatf, Alg. Danm. No. 191 ; E. Bot. t. 1929. In the sea, on sand-covered rocks, frequent. — Filaments 3 — 12 inches long, tufted, as thick as hogs' bristles, harsh to the touch, of a beautiful yellow-green colour, fading in the herbarium to a dirty white. Colouring matter of the joint finally parted in the centre. The articulations are visible to the naked eye. 10. C. collabens, Ag. ; filaments elongated, straight, tufted, very thick, gelatinous and flaccid, of a splendid aeruginose green ; articulations once and a half as long as broad. Harv. I. c. p. 354. C. area, &. lubrica, Dillw. Syn. p. 48. p 210 CONFERVA. At Yarmouth, on a floating piece of deal, Sir W. J. Hooker. — Filaments 3 or 4 inches long, twice as thick as those of C. area, of a splendid verdi- gris-green colour, which is fully preserved in drying, very gelatinous, ad- hering most closely to paper. Dissepiments much contracted. A highly beautiful plant, which, I believe, has never been found more than once. 11. C. bangioides, Harv.; filaments elongated, very slender, soft and lubricous, wavy ; joints about twice as long as broad, containing a compact, dark green mass, which is frequently bipartite ; dissepiments broad, pellucid. Harv. Phyc. Brit, t. cclxviii. In the sea, on rocks, &c. Breakwater, Plymouth, Mr. Blatch. Tor- quay, Mrs. Griffiths. Port Ballantrae, North of Ireland, Mr. Moore. — Tufts 3 — 6 inches long, of a dark green colour, lubricous, and resembling Bangia fusco-purpurea. Mixed with this plant Mrs. Griffiths frequently finds Lyngbya speciosa and a Conferva twice the diameter of C. bangioides. with contracted, bead-like joints, having most of the characters of C. Youngana, but much larger than that species usually is. 12. C. Youngana, Dillw. ; filaments short, tufted, straight, bright green, somewhat rigid,; articulations once or twice as long as broad, dissepiments finally contracted. Harv. I. c. p. 354; Dillw. t. 102. Conf. isogona, E. Sot. t. 1930. On rocks, &c. near high-water mark ; first discovered by Mr. W. W. Young, on rocks near Dunraven Castle, Glamorganshire. — Filaments an inch long, forming small tufts, somewhat rigid (as compared with C. colla- lens), obtuse. Articulations variable in length, at first cylindrical, after- wards becoming contracted in a beaded manner. *** Of doubtful affinity. 13. C. clandestina. Berk. ; " threads articulated, free, dis- tinct, uniform ; bearing reproductive granules within the joints." Berk. Gl. Alg. t. 13, /. 1. " On the under side of stones in mud highly impregnated with putrifying marine substances at Weymouth,'' Rev. M. J. Berkeley. — Filaments very minute, about a line long, at first appearing " of an opake white upon the dark mud-stained stone, gelatinous and flexuous, nearly equal throughout. Under the lens they are hyaline, and are furnished with joints about thrice as long as broad, with very evident and rather broad dissepiments and distinct granules. Sometimes the granules are wanting, probably through age.'' Berk. — Probably, as Mr. Berkeley observes, this obscure plant be- longs rather to the Leptomiti, or at least " makes a very natural transition from the more distinctly articulated Leptomiti growing on decayed vegeta- bles to the real Conferva." OCHLOCH^ETE. — ULVACE.E. 211 Sub-order 2. CH^TOPHOR^E. IV. OCHLOCH^TE. Thw. [Plate 25, E.] Frond disciform, appressed. Filaments cylindrical, radi- ating from a central point, irregularly branched, consisting of a single series of cells, each of which is most commonly produced above into a rigid inarticulate seta. Endochrome green. Fructification unknown. Thw. — Name, from o%xof, a multitude, and %« rrpcns, Lyngb. - 173 238 INDEX. PAGE roseum, Sm. - - 177 Cheetophora PAGE Rothii, L. 183 Berkley i, Grev. - 48 Rothii, /3. 183 pellita, Lyngb. - 151 secundatum, Harv. 184 Chcetospora seirospermum, Griff. 170 Wigghi, Grev. - 152 seminudum, Ag. - 179 CHLOROSPERME/E, 5,185 sparsum, Harv. 184 Chondria spongiosum, Harv. 182 parvula, Grev. - 102 tetragonum, With. 175 CHONDRUS, Grev. 135,141 tetricum, Dillw. - 176 Brodieei, Grev. - 144 thuyoideum, Sm. - 181 crispus,Z. - 141 tripinnatum, Harv. 180 norvegicus, Gunn - 142 tripinnatum, Harv. 181 CHORDA, Stack. 29,31 Turneri, Dillw. 172 filum, L. - 31 versicolor, Harv. - 170 filum, 0. - - 31 virgatulum, Harv. 184 lomentaria, Lyngb. - 32 CALOTHBIX, Ag. - 221, 223 CHORDARIA, Ag. 45,46 caespitula, Harv. - 225 divaricata, Ag. - 46 confervicola, Ag. - 224 flagelliforrais, Mull. - 46 fasciculata, Ag. hydnoides, Carm. - 224 225 paradoxa, Lyngb. CHORDARIACE^:, - 40 11,44 luteola, Grev. 224 CHRYSYJIENIA, J. Ag. 97,99 Mucor, Ag. 224 clavellosa, Turn. - - 100 pannosa, Ag. 225 clavellosa, 0. - 100 scopulorura, Web. fy Mohr 224 Orcadensis, Harv. - 100 CARPOMITRA, Kutz. - 23, 25 CHYLOCLADIA, Grev. 97, 100 Cabrerae, Clem. 25 articulata, Huds. - - 102 CATENELLA, Grev. - 136, 151 kaliformis, Good. $• Woo> iw. 101 Opuntia, Good. $• Woodw. CERAMIACE.E, - 75, 151 156 ovalis, Huds. parvula, Ag. - 101 - 102 CERAMIALES, - 6 , 64 reflexa, Chauv. - 101 CERAMIUM, Roth - 158, 161 CLADOPHORA, Kutz. - 198 acanthonotum, Carm. 165 albida, Huds. - 203 Agardhianum, Griff". 162 arcta, Dillw. - 204 brachygonium, Lyngb. 86 Brownii, Dillw. - - 199 botryocarpura, Griff. 161 diffusa, Roth - 201 ciliatum, Ellis 166 falcata, Duby - 205 ciliatutn, /3., Harv. 166 flavescens, Both - - 206 decurrens, Kutz. - 162 flexuosa, Dillw. - - 202 Deslongchampsii, Chauv. - 162 fracta, Fl. Dan. - - 206 diaphanum, Ag. - 163 glaucescens, Griff. 205 echionoturn, ,7. Ag. 165 gracilis, Griff". - 202 fastigiatum, Kutz. 164 Hutchinsiae, Dillw. . 200 flabelligerum, J. Ag. 165 laetevirens, Dillw. - 202 gracillimuin, Kutz. 163 lanosa, Roth - 204 nodosum, Kutz. - 164 Maccallana, Harv. - 200 ocellatum, Gratel. - 94 nuda, Harv. - 201 patens, Grev. 93 pellucida, Huds. - - 199 rubrum, Huds. 161 rectangularis, Griff'. - 200 strictum, Kutz. 163 refracta, Ag. - 203 Turner i, Grev. 173 repens, J. Ay. - 199 CHjETOPHORE^E, 198 Rudolphiana, Ag. - 203 INDEX. 239 rupestris, L. PAOE - 201 lanuginosa, Dillw. PAGE - 184 uncialis, Fl. Dan. - 204 Linum, Roth - 208 CLADOSTEPHUS, Ag. - 54 linum, Harv. - 208 verticillatus, Lightf. - 54 litorea, Harv. - 208 spongiosus, Huds. - 54 majuscula. Dillw. - - 226 COCCOCARPE.E, CODIUM, StacJch. - 134 - 193 melagonium, Web. $• Mohr 209 multtfida, E. Bot. - 170 adhserens, Ag. - 193 nigra, E. Bot. 91 amphibiurn, Moore - 194 nigrescens, E. Bot. - 90 Bursa, L. - 193 paradoxa, Dillw. - - 214 tomentosum, Huds. - 194 paradoxa, E. Bot. - 214 CONFERVA, Plin. 198, 207 parasitica, E. Bot. 92 aerea, Dilhv. - 209 patens, Dillw. - 82 area, [3. - 209 pedicellata, E. Bot. - 183 Arluscula, Dillw. - 94 pennata, E. Bot. - - 56 Arbuscula, R. Br. - 174 Pluma, Dillw. - 173 arenicola, Berk. - - 207 plumula, Dillw. - 171 arenosa, Carm. - 207 polymorpha, E. Bot. - 92 atro-purpurea, Dillw. - 217 pufoinata, Brown - - 199 atro-rubescens, Dillw. - 91 radicans, Dillw. - 57 bangioides, Harv. - - 210 repens, Dillw. - 173 barbata, E. Bot. - - 168 rosea, E. Bot. - 177 Borreri, E. Bot. - - 179 Rothii, E. Bot. - - 183 brachiata, E. Bot. - 64 rubra, E. Bot. - 161 Brodiati, E. Bot. - - 88 scopulorum, Dillw. - 224 byssoides, E. Bot. - 93 scutulata, Sra. - 50 centralis, Lyngb. - 205 setacea, E. Bot. - 169 ciliata, Ell. - 166 stellulata, Griff. - - 50 claiidestina, Berk. - 210 stricta, Dillw. - 83 coccinea, E. Bot. - - 93 sutoria, Berk. - 208 collabens, Ag. - 209 tetragona, E. Bot. - 175 confervicola, Dillw. - 224 tetrica, E. Bot. - - 176 corallina, E. Bot. - 169 thuyoides, E. Bot. - 181 corymbosa, E. Bot. - 182 tortuosa, Dilhv. - - 208 diaphana, E. Bot. - 163 tortuosa, Wyatt - - 206 elongata, E. Bot. - - 86 Turneri, E. Bot. - 171, 172 equisetifolia, E. Bot. - 167 ulothrix, Lyngb. - - 209 falcata, Duby - 205 urceolata, E. Bot. - - 82 fibrata, Dillw. - 83 Youngana, Dillw. - 210 flaccida, Dillw. - 50 CONFERVACE^G, 190, 196 floccosa, Fl. Dan. - - 172 CONFERVALES, 5, 185 Jloridula, Dillw. - - 183 CONFERVE^E, - - 198 fracta, j8., Ag. - 202 COBALLINA, Linn. - - 105 fucicola, Hook. fucoides, E. Bot. - - 49 - 90 elongata, Ell. f Sol. officinalis, L. - 106 - 106 fusco-purpurea, Dillw. glomerata, (3., Ag. - 217 - 202 squamata, Park. - CORALLINACE^, - 106 74, 103 Griffilhsiana, E. Bot. - 167 CORALLINES, - - 105 Hookeri, Dillw. - - 176 Corynephora marina, Ag. - • 48 implexa, Dillw. - - 209 CBOUANIA, /. Ag. - 136, 155 intricata, Grev. - 209 attenuata, Ag. . 155 isogona, E. Bot. - - 210 CRUORIA, Fries 136, 151 tfrtreeana, M'Calla - 203 pellita, Lyngb. - 151 240 CRYPTONEMIACE^E, 75, 131 E. CUTI.ERIA, Grev. 35, 36 ECTOCARPACE^E, 11, 52 multifida, Sm. - 36 ECTOCARPE^, - 54, 58 Cystoclonium ECTOCARPUS, Lyngb. 54, 58 purpurascens, Kiitz. - 131 amphibius, Harv. - - 58 CYSTOSEIRA, Ag. 14, 16 brachiatus, Harv. - - 62 barbata, Turn. 17 brachiatus, Ag. - 62 ericoides, Good, fy Woodw. 10 crinitus, Carm. - 60 foeniculacea, L. 17 distortus, Carm. - - 60 fibrosa, Huds. 17 fasciculatus, Harv. - 59 granulata, L. 16 fenestratus, Berk. - - 58 granulosus, Sm. - • 61 D. Hincksiffi, Harv. - - 59 Landsburgii, Harv. - 60 DASYA, Ag. 77, 93 littoralis, L. - 61 Arbuscula, Dillw. - 94 longifructus, Harv. - 61 coccinea, Huds. 93 Mertensii, Turn. - - 62 coccinea, ft. Hutchinsiee, Harv. - 93 94 pusillus, Griff. siliculosus, Lyngb. - 60 - 58 ocellata, Gratel. - 94 sphserophorus, Carm. - 61 simpliciuscula, Ag. spongiosa, Ag. venusta, Harv. DELESSERIA, Lamour. ill: i til, Huds. - 94 - 174 - 94 - 113 - 114 tomentosus, Huds. ELACHISTEA, Fries attenuata, Harv. - curia, Dillw. flaccida, Dillw. - - 59 46, 49 - 50 - 50 - 50 alata, y. - angustissima, Griff". Bonnemaisoni, Grev. Hillics, Grev. Hypoglossum, Woodw. interrupta, Ag. ocellata, Grev. ruscifolia, Turn. - 115 - 115 - 117 - 117 - 115 - 124 - 116 - 115 fucicola, Volley. fulvinata, Kiitz. - scutulata, Sm. stellulata, Griff". - velutina, Grev. ENTEROMORPHA, Link. clathrata, Roth clathrata, /3., Grev. - 49 - 50 - 50 - 50 - 51 212,213 - 214 - 214 sanguinea, L. - - 114 sinuosa, Good. Sf Woodw. - 1 14 clathrata, y., Grev. compvessa,i. - 215 - 213 DELESSERIACE^:, DESMARESTIA, Lamour. aculeata, L. ligulata, Lightf. - viridis, Mull. 74, 111 - 23 - 23 - 23 - 24 compressa, /3. Cornucopias, Carm. erecta, Lyngb. Hopkirkii, M'Calla intestinalis, L. - 213 - 213 - 214 - 215 - 213 intestinalis, j8. - 213 mridis, Grev. - 24 Linkiana, Grev. - - 213 DICTYOSIPHON, Grev. 35,40 percursa, Ag. - 215 fceniculaceus, Huds. DICTYOTA, Lamour. - 40 35,39 ramulosa, Sm. ramulosa minor, Wyatt - 215 - 215 dichotoma, Huds. - 39 DICTYOTACE^E, - 10,32 F. DUDRESNAIA, Bonnem. 136, 154 coccinea, Ag. - 154 FUCACE^:, 10, 11 Hudsoni, Ag. - 154 FUCALES, 4, 7 DUMONTIA, Lamour. 135, 147 Fucus, L. 14, 18 filiformis, Fl. Dan. - 147 acicularis, E. Bot. 140 filiformis, /3. - 147 alatus, E. Bot. - 114 INDEX. 241 amphibius, E. Bot. articulatus, E. Bot. asparagoides, E. Bot. balticus, Ag. bifidus, E. Bot. - Broditei, Turn. Bursa, E. Bot. PAGE 79 tomentosus, E. Bot - 102 ulvoides, Turn. 97 vesiculosus, Z,. 18 vesiculosus, /3. - 124 FURCELLARIA, Lamour. 143 fastigiata, £TM^. . PAOB - 194 - 117 - 18 - 18 135, 146 - 147 canalicnlatus, L. - 20 r capillaris, Turn. - IjT. - 152 cartilagineus, E. Bot. ceranoides, L. . 139 GASTBOCARPE^;, 19 GELIDIUM, Lamour. - - 135 134, 137 ciliatus, E. Bot. - - 126 cartilaginetim, £. - 139 clavellosus, E. Bot. - 100 corneum, ^wrfs. - - 138 coccineus, E. Bot. - 120 corneum, /3. — y. 138, 139 confervoides, E. Bot. - 130 rostra turn, Griflf. - - 115 corneus, E. Bot. - • 138 GIGARTINA, Lamour. 134, 139 coronopifolius, E. Bot. • 128 acicularis, WWf. - - 140 ortqw* , E. Bot dasyphyllus, E. Bot. . 142 mamillosus, GoW. ^ Woodw. 141 99 pistillata, Gme^. - - 140 dentatus, E. Bot. - . 78 Teedii, Turn. - 140 edulis, E. Bot. - 150 GINANNIA, Jfore<. - 136, 148 filicinus, Turn. . 137 furcellata, Turn. - - 149 fruticulosus, E. Bot. . 81 GLOIOCLADIEJE, - 136 gigartinus, E. Bot. - 140 GLOIOSIPHONIA, Carm. 136, 152 ylandulosus, E. Bot. Griffiths™, E. Bot. - 160 capillaris, Huds. - - 145 Gongroceras - 152 Jcaliformis, E. Bot. . 101 strictum, Kutz. - 164 laceratus, E. Bot. . ng GRACILARIA, Grev. - 123, 128 laciniatus, E. Bot. . 125 compressa, Ag. - 129 lumbricalis, E. Bot. . 147 confervoides, L. - 130 lycopodioides, £". .Botf. 7g confervoides, /3., y., 8. - 130 Mackaii, Twm. - 19 erecta, Grev. - 130 membranifolius, E. Bot. 143 multipartita, C/em. - 129 nodosus, L. 19 purpurascens, Grev. - 131 obtusus, E. Bot. - 98 GRATELOUPIA, ^. - 134, 137 ovalis, E. Bot. . 101 filicina, Wulf - 137 palmatus, E. Bot. _ 127 GKIFFITHSIA, Ag. 159, 167 Palmetta, E. Bot. - 125 barbata, Sm. - 168 pinastroides, E. Bot. 80 corallina, L. - 168 pinnatifidns, E. Bot. 98 Devoniensis, Hare. - 168 plicatus, E. Bot. - . 145 equisetifolia, Lightf. - 167 plumosus, E. Bot. - 159 multifida, Hook. - - 170 punctatus, E. Bot. _ llg nodulosa, Ag. - 155 purpurascens, E. Bot. 131 secundiflora, J. Ag. - 169 reniformis, E. Bot. 149 setacea, Ell. - 169 rotundus, E. Bot. . 14^ simplicifilum, Ag. - 167 rubens, E. Bot. . 143 GVMNOGONGEUS, Mart. 135, 145 sanguineus, E. Bot. - 114 GriffithsiEe, Turn. - 145 Sarniensis, Alert. - 127 ** plicata, Huds. - 145 serratus, L. - 19 sinuosus, E. Bot. - - 114 H- subfuscus, Woodw. 79 HALISERIS, Tozzetti 35, 36 tenuissimus, E. Bot. - 99 polypodioides, Desf. - 36 R* 242 INDEX. HALIDRYS, Lyngb. - PAGE 14,15 obtusa, Huds. PAOK - 98 siliquosa, L. 15 pinnatifida, Gm. - - 98 siliquosa, /3. - 15 pinnatifida, /3, y. - - 98 HALYMENIA, Ag. 136, 148 pinnatifida, y., Hook. - 98 ligulata, Woodw. - - 148 tenuissima, Good. $• W< lodw. 99 HlLDENBRANDTIAjZanOfd 105, 110 LAUBENCIACEJE, 74,95 r ubra, Menegh. - 110 LEATHESIA, Gray. - 46,48 HIMANTHALIA, Lyngb. lorea, Lyngb. 14,20 - 20 Berkeleyi, Grev. - tuberiformis, Sm. - 48 - 48 HORMOSPORA, Brieb. - 235 Lichen. ramosa, Thw. - 235 corrugatus, Dicks. - 222 HOBMOSPOBEjE, - 234 LITHOCYSTE^E ? 105, 110 Hutchinsia LITHOCYSTIS, Allm. - 105, 111 furcellata, Ag. - 92 Allmanni, Harv. - Ill penicellata, Ag. - 88 LITOSIPHON, Harv. - 35,43 subulifera, Ag. - 91 Laminaria?, Lyngb. - 43 violacea, Ag. - 87 pusillus, Carm. - 43 HYPNEA, Lamour. - 123, 130 LYNGBYA, Ag. 221, 225 purpurascens, Huds. - 131 Carmichaelii, Harv. - 226 crispa, Carm. - 226 I. ferruginea, Ag. - 226 IRIDJEA, Bory. - 136, 150 ferruginea, /3.', Ag. flacca, Dillw. - 226 - 227 edulis, Stack. - 150 majuscula, Dillw. - 226 rcniformis, Grev. - 149 speciosa, Carm. - 227 subsalsa, Carm. - 226 J. JANIA, Lamour. 105, 107 M. corniculata, L. - 107 MELANOSPERME^:, 4, 7 rubeus, L. - 107 MELOBESIA, Lamour. 105, 107 agariciformis, Pall. - 108 K. calcarea, Ell. $• Sol. - 108 KALLYMENIA, J. Ag. Dubyi, Chauv. reniformis, Turn. 136, 149 - 150 - 149 farinosa, Lamour. fasciculata, Lam. fragilis, M'Calla ? licbenoides, Borl. - 109 - 108 - 108 - 109 L. raembranacea, Lamour. - 109 polymorpha, L. - - 108 LAMINARTA, Lamour. - 29 pustulata, Lamour. - 109 bulbosa Huds. - 30 verrucata, Lamour. - 109 debilis, 'Ag. - 31 MESOGLOIA, Ag. 45,47 digitata, L. - 29 affinis, Berk. - 47 fascia, Mull. - 31 attenuata, Ag. - 155 latifolia, Ag. Phyllitis Stack. - - 30 - 31 capillaris, Ag. coccinea, Hook, - 152 - 154 saccharina, L. - 30 gracilis, Carm. - 47 saccharina, /3. - 30 Griffithsiana, Grev. - 47 LAMINABIACE.E, 10,26 moniliformis, Griff. - 155 LAURENCIA, Lamour. 96, 97 multifida, Harv. - - 153 caespitosa, Lamour. dasyphylla, Woodw. hybrida, Lenorm. - 98 - 99 - 98 purpurea, Harv. - vermicularis, Ag. - virescens, Carm. - - 153 - 47 - 47 INDEX. 243 PAOK MICROCLADIA, Grev. 158, 160 glandulosa, Soland. - 160 MICROCOLEUS, Desmaz. 222,227 anguiformis, Harv. - 227 MONORMIA, Berk. - - 231 intricate, Berk. - - 231 MVRIONEMA, Grev. - 46,51 clavatum, Carm. - - 51 Lechlancherii, Chauv. - 51 punctiforme, Lyngb. - 51 strangulans, Grev. - 51 MVRIOTIUCHIA, Harv. 54, 63 clavaeformis, Harv. - 63 filiformis, Harv. - - 63 N. NACCABIA, Endl. - 136, 152 Wigghii, Turn. - 152 NEMALEON, Targioni 136, 153 multifidum, Web. £ Mohr. 153 purpureum, Harv. - 153 NITOPHYLLUM, Grev. 113, 116 Bonnemaisoni, Ay. - 117 Gmelini, Lamour. - 118 Hilliffi, Grev. - 117 laceratum, Gmel. - - 118 lacevatum, /3. - - 1 18 ocellatum, Grev. - - 116 punctatum, With. - - 116 pvractatum, /3. - - 116 ulvoideum, Harv. - 117 versicolor, Harv. - - 118 NOSTOCHACEjE, 190,230 NULLIPOREvE, - 105, 107 O. OCHLOCH^ETE, Thw. 198,211 hystrix, Thw. - - 211 ODONTHALIA, Lyngb. - 77 dentata, L. OLIGOSIPHONIA, - - 82 OSCILLATORIA, Vauch. 222, 228 insignis, Thw. littoralis, Carm. - nigro-viridis, Thw. spiralis, Carm. - - 228 subsalsa, Ag. - 228 subuliformis, Thw. - 229 08CILLATOBIACEJG, 190,219 P. PADINA, Adans - 36, 37 deusta, Hook. - - 49 Pavonia, L. - - 37 PALMELLACE^:, 190, 234 PEYSSONELIA, Dne. - 135, 144 Dubyi, Crouan. - - 144 PHYLLOPHORA, Grev. 135, 142 Brodiaei, Turn. - - 143 membranifolius, Gd. $• Wdw. 143 Palraettoides, J. Ag. - 144 rubens, L. 1 62 PLOCAMIUM, Lamour. 113, 119 coccineum, Huds. - 119 POLYIDES, Ag. - 135, 146 rotundus, Gmel. - - 146 POLYSIPHONIA, Grev. 77, 82, 88 affinis, Moore - - 90 Agardhiana, Grev. - 91 atro-purpurea, Moore - 90 atro-rubescens, Dillw. - 91 badia, Grev. & Harv. - 91 Brodifei, Dillw. - - 88 byssoides, Good, f Woodw. 92 Carmicbaeliana, Harv. - 87 cristata, Harv. - - 88 denudata, Grev. & Harv. - 91 divaricata, Carm. - 87 elongata, Huds. - 86 elongata, /3., y. - 86 elongella, Harv. - 85 fastigiata, Roth - 92 fibrata, Dillw. 83 fihrillosa, Dillw. - formosa, Suhr. fruticulosa, Harv. - 81 'furcellata, Ag. gracilis, Grev. - - 82 Grevffiii, flair. - - 86 Griffithsiana, Horr. 85 Lyngbyeei, Harv. - 86 macroearjM, Harv. nigrescens, Huds. obscura, Ag. parasitica, Huds. - patens, Grev. pulvinata, Ag. Kicbardsoni, Harv. rosea, Grev. simulans, Hare. - 89 244 spinulosa, Grev. PAGE - 84 RHODYMENIACE.E, PAGK 75, 120 spinulosa (of Herbaria). - 89 RIVOLARIA, Roth. - 221,222 stricta, Dillw. - 83 applanata, Carm. - 223 subulifera, Ag. - 90 atra, Roth 222 subulif'era, (3. - 91 bullala, Berk. - 223 urceolata, Sm. - 82 nitida, Ag. - 223 variegata, Ag. - 88 Opuntia, E. Bot. - - 151 violacea, Ag. - 86 plicata, Carm. - 222 PORPHYRA, Ag. 212, 216 tuberiformis, Sm. - - 48 laciniata, Lightf. - 216 vermicularis, E. Bot. - 47 vulgaris, Ag. - 217 verticillata, E. Bot. - 154 /mean's, Grev. - 217 RYTIPHL.EA, Ag. 77,80 miniata, Ag. - 217 complanata, Ag. - - 80 PTILOTA, Ag. 158, 159 fruticulosa, Wulf. - 81 plumosa, L. - 159 pinastroides, Gm. - - 80 plumosa, j3., Harv. - 160 thuyoides, Harv. - - 81 sericea, Gmel. - 160 PUNCTARIA, Grev. - 35,41 S. latifolia, Grev. - 41 plantaginea, Roth - 41 SAROASSUM, Ag. 14 tenuissima, Grev. - 42 bacciferum, Turn. - 15 PYCNOPHYCUS, Kiitz. 14, 18 vulgare, Ag. - 15 tuberculatus, Huds. 18 SCHIZOTHRIX, KutZ. 221, 223 Creswellii, Harv. - - 223 R. Scytonema hydnoides, Carm. - - 225 RALFSIA, Berk. 46,49 intestinalis, /3., Lyngb. - 213 deusta, Berk. - 49 SEIROSPORA, Harv. - 159, 170 verrucosa, Aresch. - 49 Griffitbsiana, Harv. - 170 RHIZOCLONIUM, Kutz. 198,206 SIPHONACE^, - 190, 191 riparia, Roth - 206 SPERMOSEIRA, Ag. 231,233 Rhododermis litorea, Kutz. - 234 Drummondii, Harv. - 110 Harvey an a, Thw. - 234 RHODOMELA, Ag. 77,78 SPHACELARIA, Lyngb. 54,55 lycopodioides, L. - - 78 cirrbosa, Roth - 56 pinastroides, Grev. - 80 cirrhosa, /3., y. - 56 subfusca, Woodw. - 79 cirrhosa, J., Ag. - 57 RHODOMELACE^), 74,75 disticha, Lyngb. ? - - 56 RHODOSPERME^). 5,64 filicina, Gratel. - 55 RHODYMENIA, Grev. 123, 124 filicina, j3. - 55 bifida, Good. $• Woodw. - 124 fusca, Dillw. - 57 bifida, /3. . - 124 hypnoides, Grev. - - 55 ciliata, L. - 126 olivacea, Hook. - 57 cristata, L. - 126 plumosa, Lyngb, - - 56 jubata, Good. $• Woodw . - 127 racemosa, Grev. - - 57 laciuiata, Huds. - - 125 radicans, Dillw. - - 57 palmata, L. - 127 scoparia, L. - 55 palmata, /3., y. - 127 sertularia, Bonnem. - 55 Pahnetta, Esper. - 125 velutind) Grev. - 51 polycarpa, Grev. - - 129 SPHACELARlE^l, - 54 reniformis, Hook. - - 149 SPH*ROCOCCUS, Stack. 123, 128 sobolifera, Grev. - - 127 coronopifolius, Good. §• Wdw. 128 INDEX. 245 cristatus, Grev. I'AOK - 126 T. PAGE erectus, Grev. - 130 TAONIA, /. Ag. - 35,38 jubatus, Grev. - 127 alomaria, Good, fy Woi >dw. 38 tichenoides, Grev. - - 129 poiycarpus, Grev. - - 129 U. Teedii, Grev. - 141 ULVA, Linn. 212, 216 SPH&ROZYGA, Ag. - 231, 232 furcellata, E. Bol. - 149 Berkleyana, Thw. - 233 Lacluca, L. - 216 Broomei, Thw. - 233 Lacluca, E. Bot. - - 216 Carmichaelii, Haw. - 232 lalissima, L. - 216 Ralfsii, Thw. Thwailesii, Harv. - 233 - 232 ligulata, - Lii.za, L. - 148 - 216 SPIRULINA, Turp. - 222, 229 plumosa, E. Bot. - - 194 Hutchinsiae, Kutz. - 230 purpurascens, E. Bot. - 147 tenuissima, Kutz. - 229 rubens, Huds. - 154 SPONGIOCARPE^:, - 135 umbilicata, E. Bot. - 217 SPOROCHNACE^E, 10,21 ULVACE;E, 190,211 SPOROCHNE^l, - 23,25 v. SPOROCHNUS, Ag. Cabrera, Ag. 23, 25 - 26 VAUCHEBIA, D. C. 193, 195 pedunculatus, Huds. rhizodes, /3. - 25 - 40 dichotoma,fi., Ag. marina, Lyngb. - 195 - 195 villosus, Grev. - 24 submarina, Berk. - - 195 SPYRIDIA, Harv. 158, 166 velulina, Ag. - 196 filamentosa, Wulf. - 166 W STENOGRAMME, Harv. - 123 iuterrupla, Ag. STILOPHORA, J. Ag. - 124 35,39 WRANGELIA, Ag. multin'da, Huds. - 159, 169 - 170 Lyngbyei, /. Ag. - - 40 mullifida, £. - 170 rhizodes, Ehr. - 39 STRIAKIA, Grev. 35,41 . alien uata, Grev. - - 41 ZONARIA, 35,38 Grevilliana, Pollexfen - 40 parvula, Grev. - 38 GLOSSARY. Abnormal : contrary to the regular (or normal) order of growth. Accessor}/ (ramuli) : branchlets, dif- fering from the ordinary branch- lets, and fitted to a special pur- pose. Acotyledonous (plants) : plants which are propagated by spores : Cryptogamia. Acrogenous : growing from the top. Acuminated: produced into a long, slender and, usually, sharp point. Adnate : adhering to an object by the whole surface. Air-vessel : a hollow portion of the frond, filled with air. Amorphous : without definite shape. Analogue: |when a plant strik- Analogous : jingly resembles ano- ther of a different genus, or fa- mily, so as to represent it, it is said to be the analogue of that plant. Anastomose : to grow into another body, and unite with it. Apex, pi. apices thing. the top of any- Apical : belonging to the apex. Appositional (branches) : when two branches lie together, and partly unite, so as to appear like a com- pound branch. In some Confer- void Algae (Oscillatoriacece), a seemingly branched filament is composed of many simple fila- ments, so lying together; such would be called an appositionally branched filament. Appressed : closely approximated, or, (in branching), when the small- er branches lie close to the larger ones, standing very erect, Areolated: j marked out into regu- Areola, ee : Jlar spaces (or areolee), like a pavement. Articulation : when a frond consists of a single string of cells, each cell is called an articulation ; lite- rally, a joint. Articulated : having a jointed ap- pearance. Asci: membranous cases in which the spores of Lichens and Fuugi are contained. Axil : the angle formed by the in- sertion of a branch, or division of a frond. Axis: a central column; or, the central portion or medullary sub- stance of the frond. Base : the bottom of anything. Basal : belonging to the base. Branchlet : (same as ramulus) ; the ultimate division of a compound frond. Byssoid : exceedingly slender, like cobwebs. Calcareous : formed of carbonate of lime. Calli : hard parts. 248 GLOSSARY. Capitate : terminating in a knob, or head. Capitulum : a terminal knob, or head. Capillary : as slender as human hair. Capsule : a spore-case, or concep- tacle. Carnose : fleshy ; having the sub- stance of flesh. Cartilaginous : resembling gristle. Cell : — cellular tissue : when a small portion of a plant is examined under the microscope, its sub- stance is found to consist of mi- nute, membranous sacs, either empty or filled with coloured mat- ter. These sacs are called cells, and, in the aggregate, cellular tissue. Cellular (structure) : when the cells are packed together like those of a honeycomb ; or without obvious arrangement. Cellulose : the chemical substance, of which the walls of the cells are composed. Ceramidium : a conceptacle of an ovate form, pierced by a terminal pore, and containing a tuft of spores rising from the base of the cavity. (See page 69). Chlorophyll : the green matter con- tained in the cells of a plant. Cilia : properly applied to exceed- ingly minute, vibratory hairs found on the spores of certain Algae. The term cilia (literally an eye-lash) is also used for slen- der ramuli or processes fringing the margin of larger branches or lobes. Cirrhous : resembling tendrils of a vine. Class : a primary division of the vegetable kingdom, consisting of Orders ; as an order consists of Genera ; and a genus of Species, Clavate : shaped like a club, slender at the lower end and gradually thickening upwards, to a blunt point. Coccidium : a hemispherical or spherical conceptacle, without pore, containing a tuft of spores on a central placenta. (See page Compressed : between cylindrical and flat, as if a cylinder were partially flattened. Concentric : having a common cen- tre ; as when several circles are drawn one within the other. Conceptacle : a hollow case con- taining a tuft or cluster of spores. Confervoid : resembling a Conferva, that is, a thread formed of a sin- gle row of cells or articulations. Coniocystce : the name given to the fruit or sporangium of Vaucheria, Codium, &c. Constricted : partly or wholly closed by a circular fold, as if tied in by a string passed round. Continuous : without any appear- ance of joint, or other interrup- tion, internal or external. Cordate : heart-shaped. Coriaceous : having the substance of leather. Corneous : having the substance of horn. Corymbose : an arrangement of branches, where they pass off at different heights from a main stalk, and their tops are on a level or form a convex surface. Cosmopolitan : found in all parts of the world (or in most parts). Cruciate : shaped like a cross. Crustaceous : hard and expanded like a crust. Cuticle : the skin or external layer. Decumbent : lying flat, along the ground. Deflexed : bent downwards. Denticulate : having small, tooth- like projections along the margin. Dichotomous : branched by repeated forkings, each division dividing at its apex continually into two subdivisions. Dioecious : having stamens and pis- tils (or antheridia and spores) on distinct roots. GLOSSARY. 249 Dissepiment : the membrane or par- tition separating one cell, or ar- ticulation of a filament from another. Distichous : in two opposing ranks. Divaricate : spreading at very wide or obtuse angles. Ellipsoidal : of a shape most re- sembling oval. Elliptical : oval (not ovate). Embryo : the germ or young plant contained in a seed. Endochrome : the coloured contents of the cells. Epidermis •. the outer coating of cel- lular tissue. Epiphytic : growing on another ve- getable, but attached to the sur- face only. Erumpent (tetraspores) -. prominent, as if bursting through the epi- dermis. Falcate : shaped like a sickle. Fasciculate : tufted. Fastigiate : when the branches are parallel and all point upwards, as in the Lombardy poplar. Favella : a form of conceptacular fruit, described at p. 69 and p. 157. Favellidium : a favella, immersed in the frond. (See page 69). Fibro-cellular : } when the cells are Fibroso-cellular : j firm and elongat- ed and strung together in threads or filaments. Filament : a string of cells, placed end to end. Filiform : thread-shaped ; also, slen- der and cylindrical. Flabelliform : shaped like a fan. Flaccid : as if deprived of a stiffen- ing matter (familiarly limp). Flexuous : bent from side to side. Foliiferous : bearing leaves. Free : standing separate and dis- tinct ; also, unattached. Frond : the whole plant. Fusiform : shaped like a spindle or a rolling-pin, thick in the middle and tapering to either extremity. Gelatinous : having the substance of jelly. Gemmules : buds, which at length fall off and grow into new indi- viduals. Genus: a group of species, nearly related to each other, having a common character in their fructi- fication, and (usually) a simi- larity of general aspect. Gonidia : reproductive cells or germs formed in the substance of the plant, and afterwards becom- ing free and separated from the parent. Habit : the outward aspect, or ge- neral appearance which a plant has to the eye. Habitat : the place of growth in which a plant is found. Heterogeneous : having more than one nature or substance. Homogeneous : having a uniform substance or structure. Hyaline : transparent and colour- less, as water or glass. Imbricated : overlapping at the edge like the tiles on a roof. Inarticulate: without joints or in- terruptions to continuity. Inflated: swollen, as if puffed out with air. Internode : the space between two joints of a stem ; an articulation. Involucre : \ ramuli subtending a Involucrate : ) conceptacle, forming a more or less perfect whorl around it. Involute : rolled inwards. Iridescent: reflecting the change- able colours of the rainbow, or of mother-of-pearl. Lacinia : a narrow lobe or segment. Laminia : the surface of a frond, or Warfeofaleaf. Lanceolate : flat, broad in the mid- dle and narrowed to each end, like the head of a lance. Level-topped: same as fastigiale. Lichenoid : irregularly lobed, and 250 GLOSSARY. decumbent, like one of the leafy lichens (as Peltidea). Linear: long and narrow/with pa- rallel sides. Lobe: one of the portions of a deeply cut frond. Lobule : a diminution of lobe. Matrix : that from which something else is formed or developed. Membranaceous : thin and filmy ; also (when applied to substance), soft and tender, but not gelati- nous. Metamorphosed : changed in ap- pearance, or converted to another purpose. Mitriform, : shaped like a bishop's mitre, or like a loaf of sugar. Moniliform : like a string of beads. Monoecious : having stamens and pistils (or antheridia and spores) on the same root, but not in the same flower or conceptacle. Mucronate : having a small pro- jecting point, or mucro. Mucus : organic gelatine or slime. Nemathecium : a wart-like protu- berance composed of vertical fila- ments closely packed together. Node : a joint or interruption in a stem. Nodose : with swollen joints. Normal : regular, orderly. Ob : used as a prefix to a word, mean, contrary wise ; as ob-ovate, the reverse of ovate, &c. Oblong: broadly linear. O»a*ue . }thereverse of transparent. Orbicular: circular, round. Order : a group of plants consisting of numerous Genera ; the next division under a Class. Ovate : broad at one end and nar- rowed towards the other, like the outline of an egg. Palmate : divided, like a hand, into several finger-like lobes. Papillated : covered with little nip- ple or wart-like prominences, call- ed papillae. Paranemata : filaments which ac- company spores in the fructifica- tion of many Algae. (See page 9). Paraphyses : distended paranemata ; also applied to abortive spores. Parasitic : growing on another plant, and subsisting on nourish- ment derived from it. Parietal : attached to the wall or lining of a cell or conceptacle. Patent : spreading, open. Pectinated : arranged as the teeth of a comb. Pelagic : growing in many distant parts of the ocean, widely dis- persed. Penninerved (leaf or frond) : when the nerves are placed at each side of the midrib like the plumes of a feather. Percurrent: running through from top to bottom. Pericarp : the seed-vessel, or case in which spores are lodged, or the walls of the same. Peripherie : belonging to the outer stratum or periphery. Periphery : the circumference, or outer stratum of cells in a cylin- drical frond. Perispore : the case or skin which surrounds the spore. Phyllodium : a flattened, leaf-like portion of the frond. Pinna : one of a series of opposite or alternate, distichous branchlets. Pinnule : a secondary pinna. Pinnated : furnished with distichous leaves or branchlets, ranged like the plumes of a feather. Pinnatiftd : deeply incised in a se- mipinnate manner. Placenta : the part to which the spores are attached. Plumule : a pinnated branchlet. Polygonal: having many angles. Polyhedral : having many sides. Polymorphous : assuming many shapes. Process : any prominence or pro- jecting part, or small lobe. GLOSSARY. 251 Proliferous : when a new leaf or frondlet springs out of an old one. Propagulum : a reproductive por- tion of a frond, which is not a re- gular spore. Pulvinate : shaped like a cushion or pillow. Pyriform : like a pear. Quadrifarious : spreading on four sides, or (more loosely) spreading on all sides of the stem or branch. Quaternate : in fours. Racemose : having several stalked conceptacles along a branchlet. Radicle : a little root, or the fibrous part of a root. Ramellus : a diminutive of the fol- lowing. Ramulus: a minute branch, usually applied to the ultimate divisions of a branching frond. The ra- mellus is generally an appendage to the ramulus, and of different structure. Receptacle : a portion of the frond of definite shape, containing the fructification. Recurved : bent backwards. Reniform : kidney-shaped ; broader than long, very obtuse, with two shallow rounded lobes at the base. Reticulate (surface) : marked with inosculating lines, like the meshes of a net-work ; or formed of large, flat, polygonal cells. Retiform : like a net-work. Revolute : rolled back. Secund : arranged along one side only. Septum : a partition. Serrated : toothed like the edge of a saw : the teeth are called serra- tures. Sessile : having no stalk. Setaceous : equal in diameter to a a hog's bristle. Setiform : shaped like a bristle. Siliculess little pod-like fruits. Sinuated: when the margin has numerous shallow, obtuse inden- tations. Sorus, pi. son : a cluster of spores. Sporaceous : convertible into spores. Sporangium : a spore-case, with its contents. Spore : the representative of seed in ciyptogamic plants. It is in all cases a simple cell. Sporidium : a reproductive, spore- like body, but not a true spore. Sporophylla : small leafy lobes, con- taining tetraspores. Stichidia : pod-like receptacles con- taining tetraspores. Stipes : the stem or stalk of a leafy frond. Stipitate: having a stem or stalk. Stratum : a layer. Stria : a narrow line or mark. Stupose : covered with woolly hairs. Subulate : shaped like an awl. Tentacular: resembling the tenta- cula or feelers of a snail, long and slender. Terete : round, in opposition to flat. Ternate: in threes. Temately-parted (tetraspores) : when only three of the sporules are seen at one view. Tetraspore : a spore or gemmule dividing at maturity into four parts. Transverse : across. Trichotomous : dividing continually in threes. Truncate : terminating abruptly, as if broken off. Tubercle : a term synonymous with coccidium. Type : generally means, as here used, the perfect representation or idea of anything : thus, a typi- cal specimen embodies the cha- racteristics of the species in an eminent degree, &c. Ultra : more than. Urceolate: shaped like an ancient pitcher, egg-shaped, with a nar- row protruding mouth. 252 GLOSSARY. Virgate : long and straight, like a Zoned (tetraspores) : when the te- wand. traspore is divided into rings or zones, by cross lines. Whorled : surrounding a branch, in Zoospores : spores (or gemmules) a ring. which have a proper locomotive power, resembling the voluntary Zigzag : angularly bent from side motions of animals, to side. Copies of this Work, with the Figures additionally Coloured by hand, may be had, Price £1 I Is. Qd. " PLATE I. A. SARGASSUM, page 14. Fig. 1, a branch of S. vulgare; the natural size. 2, a receptacle. 3, section of the same. 4, a spore. 5, a vesicle, cut open ; all more or less magnified. B. CYSTOSEIRA, page 16. Fig. 1, a branch of C. fibrosa ; the natural size. 2, a receptacle and vesicle. 3, section of the receptacle. 4, a spore ; all magnified. C. HALIDRYS, page 15. Fig. 1, part of a branch of H. siliquosa; the natural size. 2, a vesicle, cut open, showing the internal septa, connected by slender threads. 3, part section of a receptacle. 4, spore ; all magnified. D. Fucus, page 18. Fig. 1, part of a frond of F. vesiculosus ; the natural size. 2, part section of a receptacle, showing three conceptacles. 3, a spore, containing eight sporules ; both magnified. PLATE II. A. PYCNOPHYCUS, page 18. Fig. 1, P. tuberculatus ; the natural size. 2, part of cross section of a receptacle. 3, a spore ; magnified. B. HIMANTHALIA, page 20. Fig. 1, H. lorea ; young and full-grown plants. 2, part of cross section of a receptacle. 3, a spore, containing four sporules ; magnified. PLATE III. A. ALARIA, page 29. Fig. 1, A. esculenta ; the natural size. 2, part of cross section of a sorus. 3, spores from the same ; mag- nified. B. CHORDA, page 31. Fig. 1, Chorda filum ; the natural size. 2, vertical section of the frond. 3, vertical section of a small portion of the wall, showing the large internal cells and the stratum of spores. 4, spores from the same. 5, an antheridium ? ; all magnified. PL 3 PLATE IV. LAMINARIA, page 29. Fig. 1, L. digitata; showing the form of the full- grown frond. 2, the same, in the act of throwing off the frond of the previous season ; both figures on a reduced scale. 3, cross section of the frond. 4, spores ; both magnified. PLATE V. A. SPOROCHNUS, page 25. Fig. 1, S. pedunculatus ; the natural size. 2, recep- tacles. 3, spores and filaments from the same. 4, one of the fibres of the crest. 5, cross section of the stem ; all magnified. B. CARPOMITRA, page 25. Fig. 1, C. Cabreras ; the natural size. 2, portion of the frond, with a fertile branch. 3, receptacle. 4, filament from the same. 5, cross section of the frond ; magnified. C. ARTHROCLADIA, page 24. Fig. 1, branch of A. villosa ; the natural size. 2, small part of the frond. 3, pods, containing spores. 4, longitudinal section of the frond. 5, cross section of the same ; all magnified. D. DESMARESTIA, page 23. Fig. 1, branch of D. aculeata ; the natural size. 2, longitudinal, and 3, cross, sections of the stem, mag- nified. 4, branch of D. ligulata, the natural size. /V. J PLATE VI. A. CUTLERIA, page 35. Fig. 1, C. multifida ; the natural size. 2, a morsel of the frond with a sorus. 4, antheridia. 5, trans- verse, and 6, longitudinal, sections of the frond; magnified. B. HALISERIS, page 36. Fig. 1, H. polypodioides ; the natural size. 2, morsel of the frond with scattered spores. 3, small portion with sorus. 4, spores ; magnified. C. PADINA, page 37. Fig. 1, P. Pavonia ; the natural size. 2, a sorus. 3, spores. 4, circinate apex of the frond, with fringe ; magnified. D. ZONARIA, page 38. Fig. 1, Fronds of Z. parvula, on a piece of Nullipore. 2, portion of the frond. 3, cellular structure of the surface ; magnified. PLATE VII. A. DICTYOTA, page 39. Fig. 1, D. dichotoma; the natural size. 2, sorus, on a small portion of the frond. 3, vertical section of the same. 4, spore, containing four sporules. 5, fragment of the frond with scattered spores ; magni- fied, B. TAONIA, page 38. Fig. 1, T. Atomaria ; the natural size. 2, portion of the frond, showing spores in bands and scattered. 3, section of the frond with spores in situ ; mag- nified. C. STILOPHORA, page 39. Fig. 1 , S. rhizodes ; the natural size. 2, fragment of the frond, with sori. 3, cross section of frond and sorus. 4, spore and filament or paranema. D. DICTYOSIPHON, page 40. Fig. 1, D.fceniculacens ; the natural size. 2, portion of the frond, with scattered spores. 3, spore. 4, cross section of a younger portion, and 5, of an older portion, of the frond. 6, cellular tissue from the interior of the same ; all magnified. /Y 7 PLATE VIII. A. STRIARIA, page 41. Fig. 1 , S. attenuata ; the natural size. 2, small por- tion of the frond, with sori in transverse rows. 8, a sorus on a fragment of the frond. 4, a spore ; all magnified. B. PUNCTARIA, page 41. Fig. 1, P. plantaginea ; the natural size. 2, small portions of the frond with scattered spores. 3, small portions with a sorus. 4, section of frond through the centre of a sorus. 5, spores ; all magnified. C. ASPEROCOCCUS, page 42. Fig* 1, A. Turneri ; the natural size. 2, small por- tion of the surface with sori. 3, section of frond and sorus. 4, spore ; all magnified. D. LITOSIPHON, page 43. Fig. 1, Tuft of L. pusillus; the natural size. 2, por- tion of a frond, clothed with hairs. 3, small portion of the same with spores. 4, 5, cross sections of the frond ; all magnified. PLATE IX. A. CLADOSTEPHUS, page 54. Fig. 1, C. verticillatus ; the natural size. 2, a whorl of ramuli on a fragment of the stem. 3, a barren ramulus. 4, a fertile ramulus, from a winter speci- men. 5, cross section of the stem ; magnified. B. SPHACELARIA, page 55. Fig. 1, S. scoparia; the natural size. 2, pinnated branch or plumuli from the same ; magnified. 3, S. cirrhosa, the natural size. 4, plumuli of the same. 5, apex of a ramulus, with sphacelated tip. 6, part of ramulus, with fruit ; magnified. C. ECTOCARPUS, page 58. Fig. 1, E. siliculosus ; the natural size. 2, silicular spore of the same. 3, branch with fruit. 4, branch of E. littoralis, in fruit. 4, immersed spore. D. MYRIOTRICHIA, page 63. 1, Tufts of M. claveeformis growing on Chorda lomen- taria ; the natural size. 2, a frond. 3, ramulus, spore and fibres, from the same ; magnified. /'/. .v PLATE X. A. CHORDARIA, page 46. Fig. 1, C. jiagelliformis ; the natural size. 2, seg- ment of a cross section of the frond. 3, longitudinal slice. 4, spore and paranema ; magnified. B. MESOGLOIA, page 47. Fig. 1, M. virescens ; the natural size. 2, small por- tion of the frond. 3, filaments from the same ; mag- nified. C. LEATHESIA, page 48. Fig. 1, L. tuber if or mis ; the natural size. 2, vertical section of the same ; magnified. 3, L. Berkeleyi ; the natural size. 4, filaments from the same ; rnag- D. RALFSIA, page 49. Fig. 1, R. deusta ; the natural size. 2, vertical sec- tion of frond, with sori. 3, filaments composing the periphery of the frond. 4, spore and paranemata from a sorus ; magnified. E. MYRIONEMA, page 51. Fig. 1, M. punctiforme, growing on Ceramium rubrum; the natural size. 2, a plant of the parasite on a joint of the Ceramium. 3, spores and filaments ; magnified. F. ELACHISTEA, page 49. Fig. 1, E.fucicola, growing on Fucus vesiculosus ; the natural size. 2, a small part of the parasite, showing a dichotomous filament from the tubercle ; the fila- ments or paranemata of the spores ; the spores, and the bases of the long, free filaments, all in situ. 3, spore and paranemata ; magnified. PUO PLATE XI. A. ODONTHALIA, page 77. Fig. 1, O. dentata ; a branch, the natural size. 2, tuft of ceramidia. 3, spores from the same. 4, tuft of stichidia. 5, a tetraspore ; all magnified. B. RHODOMELA, page 78. Fig. 1, Branch of R. subfusca ; the natural size. 2, small ramulus with young ceramidia. 3, a cera- midium. 4, stichidia (borne in winter). 5, a tetras- pore. 6, cross section of the frond ; all magnified. C. BOSTRYCHIA, page 79. Fig. 1, B. scorpioides ; the natural size. 2, apex of a branch. 3, cross section of the frond. 4, longitudi- nal section of the same ; magnified. D. RYTIPHL/EA, page 80. Fig. 1, R. pinastroides ; the natural size. 2, ramuli bearing stichidia. 3, a stichidium. 4, ramuli bear- ing ceramidia. 5, a ceramidium. 6, longitudinal section of the frond ; all magnified. Pill. PLATE XII. A. POLYSIPHONIA, page 82. Fig. 1, P. variegata ; the natural size. 2, a cera- raidium. 3, a spore. 4, ramulus with immersed te- traspores. 5, a tetraspore. 6, small portion of the stem. 7, cross section of the same, to show the six siphons, surrounding the central tube ; all magnified. B. DASYA, page 93. Fig. 1, D. arbuscula ; the natural size. 2, ramellus bearing stichidia. 3, a ceramidium. 4, cross sec- tion of the stem ; all magnified. C. LAURENCIA, page 97. Fig. 1, L. pinnatifida ; the natural size. 2, apex of branch with tetraspores. 3, a tetraspore. 4, apex of a branch with ceramidia. 5, spores ; all magnified. D. BONNEMAISONIA, page 97. Fig. 1, B. asparagoides ; the natural size. 2, apex of a branch, with ceramidia alternating with the ra- muli. 3, a ceramidium. 4, a spore ; all magnified. PU2. PLATE XIII. A. CHRYSYMENIA, page 99. Fig, 1, C. clavellosa, a small plant ; the natural size. 2, rainulus with imbedded tetraspores. 3, a tetra- spore. 4, small branch, with ceramidia on its ra- muli. 5, a ceramidium ; all magnified. B. CHYLOCLADIA, page 100. Fig. 1, C. kaliformis, a small plant ; the natural size. 2, apex, bearing ceramidia on the ramuli. 3, a cera- midium. 4, tufted spores from the same. 5, apex having tetraspores imbedded in the ramuli. 6, a tetraspore ; all magnified. C. CORALLINA, page 105. Fig. 1, C. officinalis ; the natural size. 2, small part of the frond, with terminal ceramidia. 3, a cera- midium cut open. 4, a tetraspore. 5, small part of the frond, after the lime has been removed ; magnified. D. JANIA, page 107. Fig. 1 . Tufts of J. rubens, the natural size. 2, a fer- tile branch of the same. 3, ceramidium. 4, tetra- spores, from the same. 5, part of an articulation of the frond, after the lime has been removed; magnified. PLATE XIV. A. MELOBESIA, page 107. Fig. 1, M. fasciculata. 2, leaf of Zostera, on which M. membranacea is growing ; both the natural size. 3, fronds of M. membranacea ; magnified. B. LITHOCYSTIS, page 111. Fig. 1, Part of a frond of Chrysymenia clavellosa, on which L. Allmanni is growing; the natural size. 2, fronds of L. Allmanni ; very highly magnified. C. HlLDENBRANDTIA, page 110. Fig. 1, H. rubra, growing on a pebble; the natural size. 2, small portion of the frond, viewed vertically. 3, vertical section of the frond, cut through a con- ceptacle. 4, a tetraspore ; all magnified. D. PEYSSONELIA, page 144. Fig. 1, P. Dubyi, growing on a fragment of stone ; the natural size. 2, vertical section, cut through a wart. 3, tetraspores ; both highly magnified. n /•* .. I PLATE XV. A. DELESSERIA, page 113. Fig. 1, D. sanguinea ; 2, winter branch with sporo- phylla; the natural size. 3, a sporophyllum or leaflet, containing tetraspores. 4, a tetraspore ; mag- nified. 5, a winter branch with coccidium ; the na- tural size. 6, a coccidium on its stalk. 7, spores ; magnified. B. NITOPHYLLDM, page 116. Fig. 1, N. punctatum ; the natural size. 2, frag- ment with spores. 3, a tetraspore. 4, fragment with tubercle. 5, spores from the same ; magnified. C. PLOCAMIUM, page 119. Fig. 1, P. coccineum ; the natural size. 2, branch with tubercle. 3, tubercle further enlarged. 4, branch with sporophylla. 5, a sporophyllum. 6, a tetraspore from the same ; all magnified. D. STENOGRAMME, page 123. Fig. 1, S. interrupta ; the natural size. 2, portion of the frond, with young and mature fruit. 3, section of the frond ; magnified. a «2) /«? IF \r 4 > Jf %^^ PLATE XVI. A. RHODYMENIA, page 124. Fig. 1, R. laciniata ; the natural size. 2, 8, portions of the margin, with coccidia of different sizes. 4, portion of the margin, with sorus. 5, tetraspores ; all magnified. B. SPH^ROCOCCUS, page 128. Fig. 1, S. coronopifolius ; the natural size. 2, frag- ment, with fructification. 3, a tubercle. 4, longi- tudinal, and 5, transverse, slices of the frond; magni- C. GRACILARIA, page 128. Fig. 1, G. confervoides ; the natural size. 2, vertical sections of tubercle. 3, longitudinal, and 4, trans- verse, slices of the frond. D. HYPNEA, page 130. Fig. 1, H. purpurascens ; the natural size. 2, frag- ment of a branch, with imbedded tubercles. 3, a tetraspore. 4, longitudinal, and 5, transverse, slices of the frond ; all magnified. Pi.16 PLATE XVII. A. GRATELOUPIA, page 137. Fig. 1, G. filicina ; the natural size. 2, branch with tetraspores. 3, longitudinal section of the same. 4, a tetraspore. 5, branchlet with favellidia. 6, transverse section of the same ; magnified. B. GELIDIUM, page 137. Fig. 1, G. corneum. 2, the same, var. latifolium ; both the natural size. 3, a ramulus with tetraspores. 4, tetraspores (dispores). 5, a favellidium imbedded in a swollen ramulus. 6, spores ; all magnified. C. GIGARTINA, page 139. Fig. 1, G. acicularis ; the natural size. 2, branchlet with fruit. 3, vertical section of a fruit. 4, longitu- dinal slice of the frond ; all magnified. D. CHONDRUS, page 141. Fig. 1, C. crispus ; the natural size. 2, cross section of an imbedded sorus. 3, a tetraspore. 4, longitu- dinal slice of the frond ; magnified. PLATE XVIII. A. PHYLLOPHORA, page 142. Fig. 1, P. rubens ; the natural size. 2, a nemathe- cium. 3, filaments from the same. 4, tubercles. 5, spores from the same ; all magnified. B. GYMNOGONGRUS, page 145. Fig. 1, G. Griffithsi