Chapter 14

[FG]“Acadian Geology,” “Reports on Fossil Plants of Canada,” Geological Survey of Canada.

[FH]“Geological Surveys of Pennsylvania, Ohio, and Illinois.”

In this connection I am reminded, by an excellent little paper of M. Zeiller,[FI]on Carboniferous plants from the region of the Zambesi, in Africa, that the flora which in the Carboniferous period extended over the temperate portions of the northern hemisphere and far into the arctic, also passed across the equator and prevailed in the southern hemisphere. Of eleven species brought from the Zambesi by M. Lapierre and examined by M. Zeiller, all were identical with Europeanspecies of the upper coal-formation, and the same fact has been observed in the coal flora of the Cape Colony.[FJ]These facts bear testimony to the remarkable uniformity of climate and vegetation in the coal period, and I perfectly agree with Zeiller that they show, when taken in connection with other parallelisms in fossils, an actual contemporaneousness of the coal flora over the whole world.

[FI]Paris, 1883.

[FJ]Grey, “Journal of the Geological Society,” vol. xxvii.

1. Carboniferous Flora.

(1)Permo-Carboniferous Sub-Flora:

This occurs in the upper member of the Carboniferous system of Nova Scotia and Prince Edward Island, originally named by the writer the Newer Coal-formation, and more recently the Permo-Carboniferous, and the upper beds of which may not improbably be contemporaneous with the Lower Permian or Lower Dyas of Europe. In this formation there is a predominance of red sandstones and shales, and it contains no productive beds of coal. Its fossil plants are for the most part of species found in the Middle or Productive Coal-formation, but are less numerous, and there are a few new forms akin to those of the European Permian. The most characteristic species of the upper portion of the formation, which has the most decidedly Permian aspect, are the following:

Of these species, those marked with an asterisk have not yet been found in the middle or lower members of the Carboniferous system. They will be found described, and several of them figured, in my “Report on the Geology of Prince Edward Island.”[FK]The others arecommon and widely diffused Carboniferous species, some of which have extended to the Permian period in Europe as well. From the upper beds, characterised by these and a few other species, there is a gradual passage downward into the productive coal-measures, and a gradually increasing number of true coal-formation species.

[FK]1871.

It is worthy of remark here that the association in the Permo-Carboniferous of numerous trunks ofDadoxylonwith the branches ofWalchiaand with fruits of the character ofTrigonocarpa, seems to show that these were parts of one and the same plant.

This formation represents the Upper Barren Measures of West Virginia, which are well described by Fontaine and White,[FL]and the reasons which these authors adduce for considering the latter equivalent to the European Permian will apply to the more northern and eastern deposits as well, though these have afforded fewer species of plants, and are apparently less fully developed.

[FL]“Report on the Permian Flora of Western Virginia and South Pennsylvania,” 1880.

(2)Coal-formation Sub-Flora:

The Middle or Productive Coal-formation, containing all the beds of coal which are mined in Nova Scotia and Cape Breton, is the headquarters of the Carboniferous flora. From this formation I have catalogued[FM]one hundred and thirty-five species of plants; but, as several of these are founded on imperfect specimens, the number of actual species may be estimated at one hundred and twenty. Of these more than one half are species common to Europe and America. No less than nineteen species areSigillariæ, and about the same number areLepidodendra. About fifty are ferns and thirteen areCalamites,Asterophyllites, andSphenophylla. The great abundance and number of species of Sigillariæ, Lepidodendra, and ferns are characteristic of this sub-flora; and among the ferns certain species ofNeuropteris,Pecopteris,Alethopteris, andSphenopterisgreatly preponderate.

[FM]“Acadian Geology,” and “Report on Flora of Lower Carboniferous,” 1873.

These beds are the equivalents of the Middle Coal-measures, or Productive Coal-measures of Pennsylvania, Ohio, &c., and of the coal-formation proper of various European countries. Very many of the species are common to Nova Scotia and Pennsylvania; but in proceeding westward the number of identical species seems to diminish.

(3)The Millstone Grit Sub-Flora:

In this formation the abundance of plants and the number of species are greatly diminished.[FN]Trunks of coniferous trees of the speciesDadoxylon Acadianum, having wide wood-cells with three or more series of discs and complex medullary rays, become characteristic.Calamites undulatumis abundant and seems to replaceC. Suckovii, thoughC. cannæformisandC. cistiicontinue.Sigillariæbecome very rare, and the species of Lepidodendron are few, and mostly those with large leaf-bases.Lepidophloiosstill continues, andCordaitesabounds in some beds. The ferns are greatly reduced, though a few characteristic coal-formation species occur, and the genusCardiopterisappears. Beds of coal are rare in this formation; but where they occur there is in connection with them a remarkable anticipation of the rich coal-formation flora, which would thus seem to have existed locally in the Millstone Grit period, but to have found itself limited by generally unfavorable conditions. In America, as in Europe, it is in the north that this earlier development of the coal-flora occurs, while in the south there is a lingering of old forms in the newer beds. In Newfoundland and Cape Breton, for instance, as well as in Scotland, productive coal-beds and a greater variety of species of plants occur in this formation.

[FN]“Report on Fossil Plants of the Lower Carboniferous and Millstone Grit of Canada,” 1873.

The following would appear to be the equivalents of this formation, in flora and geological position:

1. The Seral Conglomerate of Rogers in Pennsylvania, &c.

2. The Lower Coal-formation Conglomerate and Chester groups of Illinois (Worthen).

3. The Lower Carboniferous Sandstone of Kentucky, Alabama, and Virginia.

4. The Millstone Grit and Yoredale rocks of northern England, and the Culmiferous of Devonshire.

5. The Moor rock and Lower Coal-measures of Scotland.

6. Flagstones and Lower Shales of the south of Ireland, and Millstone Grit of the north of Ireland.

7. The Jüngste Grauwacke of the Hartz, Saxony, and Silesia.

(4)The Carboniferous Limestone Series:

This affords few fossil plants in eastern America, and in so far as known they are similar to those of the next group. In Scotland it is richer in plants, but, according to Mr. Kidston, these are largelysimilar to those of the underlying beds, though with some species which extend upward into the Millstone Grit. In Scotland the alga namedSpirophytonandArchæocalamites radiatus—which in America are Erian—appear in this formation.

(5)The Lower Carboniferous Sub-Flora:

This group of plants is best seen in the shales of the Horton series, under the Lower Carboniferous marine limestones. It is small and peculiar. The most characteristic species are the following:

Dadoxylon(Palæoxylon)antiquius, Dn.—A species with large medullary rays of three or more series of cells.

Lepidodendron corrugatum, Dn.—A species closely allied toL. Veltheimianumof Europe, and which is its American representative. This is perhaps the most characteristic plant of the formation. It is very abundant, and presents very protean appearances, in its old stems, branches, twigs, andKnorriaforms. It had well-characterised stigmaria roots, and constitutes the oldest erect forest known in Nova Scotia.

Lepidodendron tetragonum, Sternberg.

L. obovatum, Sternb.

L. aculeatum, Sternb.

L. dichotomum, Sternb.

The four species last mentioned are comparatively rare, and the specimens are usually too imperfect to render their identification certain, but Lepidodendra are especially characteristic trees of this horizon.

Cyclopteris(Aneimites)Acadica, Dn.—A very characteristic fern, allied in the form of its fronds toC. tenuifoliaof Goeppert, toC. nanaof Eichwald, and toAdiantites antiquusof Stur. Its fructification, however, is nearer to that ofAneimiathan to that ofAdiantum.

Ferns of the genera Cardiopteris andHymenophyllitesalso occur, though rarely.

Ptilophyton plumula, Dn.—This is the latest appearance of this Erian genus, which also occurs in the Lower Carboniferous of Europe and of the United States.

Cordaites borassifolia, Brongt.

On the whole, this small flora is markedly distinct from that of the Millstone Grit and true coal-formation, from which it is separated by the great length of time required for the deposition of the marine limestones and their associated beds, in which no land-plantshave been found; nor is this gap filled up by the conglomerates and coarse arenaceous beds which, as I have explained in “Acadian Geology,” in some localities take the place of the limestones, as they do also in the Appalachian region farther south.

The palæobotanical and stratigraphical equivalents of this series abroad would seem to be the following:

1. The Vespertine group of Rogers in Pennsylvania.

2. The Kinderhook group of Worthen in Illinois.

3. The Marshall group of Winchell in Michigan.

4. The Waverley sandstone (in part) of Ohio.

5. The Lower or False Coal-measures of Virginia.

6. The Calciferous sandstones of McLaren, or Tweedian group of Tate in Scotland.

7. The Lower Carboniferous slate and Coomhala grits of Jukes in Ireland.

8. The Culm and Culm Grauwacke of Germany.

9. The Graywacke or Lower Coal-measures of the Vosges, as described by Schimper.

10. The Older Coal-formation of the Ural, as described by Eichwald.

11. The so-called “Ursa Stage” of Heer includes this, but he has united it with Devonian beds, so that the name cannot be used except for the local development of these beds at Bear Island, Spitsbergen. The Carboniferous plants of arctic America, Melville Island, &c., as well as those of Spitzbergen, appear all to be Lower Carboniferous.[FO]

[FO]“Notes on Geological Map of the Northern Portion of the Dominion of Canada,” by Dr. G. M. Dawson, 1887.

All of the above groups of rocks are characterised by the prevalence ofLepidodendraof the type ofL. corrugatum,L. Veltheimianum, andL. Glincanum; pines of the sub-genusPitusof Witham,Palæoxylonof Brongniart, and peculiar ferns of the generaCyclopteris,Cardiopteris,Triphyllopteris, andSphenopteris. In all the regions above referred to they form the natural base of the great Carboniferous system.

In Virginia, according to Fontaine and White, types, such as Archæopteris, which in the north are Upper Erian, occur in this group. Unless there have been some errors in fixing the lower limit of the Vespertine, this would indicate a longer continuance of old forms in the south.

2. Erian Flora.

(1)Upper Erian Sub-Flora:

This corresponds to the Catskill and Chemung of the New York series, and to the Upper Devonian of Europe.

The flora of this formation, which consists mostly of sandstones, is not rich. Its most distinctive species on both sides of the Atlantic seem to be the ferns of the genusArchæopteris, along with species referred to the genusCyclopteris, but which, in so far as their barren fronds are concerned, for the most part resembleArchæopteris.

The characteristic American species areArchæopteris Jacksoni,A. Rogersi, andA. Gaspiensis.Cyclopteris obtusaandC.(Platyphyllum)Browniiare also very characteristic species. In Europe,Archæopteris Hibernicais a prevalent species.

Leptophleum rhombicumand fragments ofPsilophytonare also found in the Upper Erian. There is evidence of the existence of vast numbers ofRhizocarpsin this period, in the deposits of spore-cases (Sporangites Huronensis) in the shales of Kettle Point, Lake Huron; and in deposits of similar character in Ohio and elsewhere in the West.

The Upper Erian flora is thus very distinct from that of the Lower Carboniferous, and the unconformable relation of the beds in the Northeast may perhaps indicate a considerable lapse of time. Still, even in localities where there appears to be a transition from the Carboniferous into the Devonian, as in the Western States and in Ireland, the characteristic flora of each formation may be distinguished, though, as already stated, there is apparently some mixture in the South.

(2)Middle Erian Sub-Flora:

Both in Canada and the United States that part of the great Erian system which may be regarded as its middle division, the Hamilton and Marcellus shales of New York, the Cordaites shales of St. John, New Brunswick, and the middle shales and sandstones of the Gaspé series, presents conditions more favourable to the abundant growth of land-plants than either the upper or lower member. In the St. John beds, in particular, there is a rich fern flora, comparable with that of the coal-formation, and numerous stipes of ferns and trunks of tree-ferns have been found in the Hamilton and Corniferous series in the West, as well as trunks ofDadoxylon. It is, however, distinguished by a prevalence of small and delicate species, and by such forms asHymenophyllitesand the smaller Sphenopterids, and also by some peculiar ferns, asArchæopterisandMegalopteris.In addition to ferns, it has smallLepidodendra, of whichL. Gaspianumis the chief.Calamiteæoccur,Archæocalamites radiatusbeing the dominant species. This plant, which in Europe appears to reach up into the Lower Carboniferous, is so far strictly Erian in northeast America.Sigillariæscarcely appear, butCordaitesis abundant, and the earliest known species ofDadoxylonappear, while the Psilophyton, so characteristic of the Lower Erian, still continues, and the remarkable aquatic plants of the genusPtilophytonare locally abundant.

(3)Lower Erian Sub-Flora:

This belongs to the Lower Devonian sandstones and shales, and is best seen in that formation at Gaspé and the Bay des Chaleurs. It is equivalent to the Oriskany sandstone, so far as its animal fossils and mineral character are concerned. It is characterised by the absence of true ferns,CalamitesandSigillariæ, and by the presence of such forms asPsilophyton,Arthrostigma,Leptophleum, andNematophyton.Lepidodendron GaspianumandLeptophleumalready occur, though not nearly so abundant as Psilophyton.

The Lower Erian plants have an antique and generalised aspect which would lead us to infer that they are near the beginning of the land-flora, or perhaps in part belong to the close of an earlier flora still in great part unknown and few indications of land-plants have been found earlier.

At Campbellton and Scaumenac Bay, on the Bay des Chaleurs, fossil fishes of genera characteristic of the Lower and Upper Devonian horizons respectively, occur in association with fossil plants of these horizons, and have been described by Mr. Whiteaves.[FP]

[FP]“Transactions of the Royal Society of Canada.”

It is interesting to note that, as Fontaine and White have observed, certain forms which are Erian in the northeast are found in the Lower members of the Carboniferous in West Virginia, indicating the southward march of species in these periods.

3. The Silurian Flora and still Earlier Indications of Plants.

In the upper beds of the Silurian, those of the Helderberg series, we still findPsilophytonandNematophyton; but below these we know no land-plants in Canada. In the United States, Lesquereux and Claypole have described remains which may indicate the existence of lycopodiaceous and annularian types as far back as the beginningof the Upper Silurian, or even as low as the Hudson River group, and Hicks has foundNematophytonandPsilophytonin beds about as old in Wales, along with the uncertain stems namedBerwynia. In the Lower Silurian theProtannulariaof the Skiddaw series in England may represent a land-plant, but this is uncertain, and no similar species has been found in Canada.

The Cambrian rocks are so far barren of land-plants; the so-calledEophytonbeing evidently nothing but markings, probably produced by crustaceans and other aquatic animals. In the still older Laurentian the abundant beds of graphite probably indicate the existence of plants, but whether aquatic or terrestrial it is impossible to decide at present.

It would thus appear that our certain knowledge of land-vegetation begins with the Upper Silurian or the Silurio-Cambrian, and that its earliest forms were Acrogens allied to Lycopods, and prototypal trees, forerunners of the Acrogens or the gymnosperms. In the Lower Devonian little advance is made. In the Middle Devonian this meagre flora had been replaced by one rivalling that of the Carboniferous, and including pines, tree-ferns, and arboreal forms of Lycopods and of equisetaceous plants, as well as numerous herbaceous plants. At the close of the Erian the flora again became meagre, and continued so in the Lower Carboniferous. It again became rich and varied in the Middle Carboniferous, to decay in the succeeding Permian.

II.—HEER’S LATEST RESULTS IN THE GREENLAND FLORA.

A veryvaluable report of Prof. Steenstrup, published in Copenhagen in 1883, the year in which Heer died, contains the results of his last work on the Greenland plants, and is so important that a summary of its contents will be interesting to all students of fossil botany or of the vicissitudes of climate which the earth has undergone.[FQ]

[FQ]Meddelelser om Gronland, Hefte V., Copenhagen, 1883.

The plant-bearing beds of Greenland are as follows, in ascending order:

1.Cretaceous.

1. TheKoméseries, of black shales resting on the Laurentian gneiss. These beds are found at various other localities, but thename above given is that by which they are generally known. Their flora is limited to ferns, cycads, conifers, and a few endogens, with onlyPopulus primævato represent the dicotyledons. These beds are regarded as Lower Cretaceous (Urgonian), but the animal fossils would seem to give them a rather higher position. They may be regarded as equivalent to the Kootanie and Queen Charlotte beds in Canada, and the Potomac series in Virginia.

2. TheAtanéseries. These also are black shales with dark-coloured sandstones. They are best exposed at Upernavik and Waigat. Here dicotyledonous leaves abound, amounting to ninety species, or more than half the whole number of species found. The fossil plants resemble those of the Dakota series of the United States and the Dunvegan series of Canada, and the animal fossils indicate the horizon of the Fort Pierre or its lower part. They may be regarded as representing the lower part of the Upper Cretaceous. The generaPopulus,Myrica,Quercus,Ficus,Platanus,Sassafras,Laurus,Magnolia, andLiriodendronare among those represented in these beds, and the peculiar generaMacclintockiaandCredneriaare characteristic. The genusPinusis represented by five species,Sequoiaby five, andSalisburiaby two, with three of the allied genusBaiera. There are many ferns and cycads.

3. ThePatootseries. These are yellow and red shales, which seem to owe their colour to the spontaneous combustion of pyritous lignite, in the manner observed on the South Saskatchewan and the Mackenzie rivers. Their age is probably about that of the Fox-Hill group or Senonian, and the Upper Cretaceous of Vancouver Island, and they afford a large proportion of dicotyledonous leaves. The genera of dicotyledons are not dissimilar from those of Atané, but we now recogniseBetulaandAlnus,Comptonia,Planera,Sapotacites,Fraxinus,Viburnum,Cornus,Acer,Celastrus,Paliurus,Ceanothus,Zizyphus, andCratægusas new genera of modern aspect.

On the whole there have been found in all these beds 335 species, belonging to 60 families, of which 36 are dicotyledonous, and represent all the leading types of arborescent dicotyledons of the temperate latitudes. The flora is a warm temperate one, with some remarkable mixtures of sub-tropical forms, among which perhaps the most remarkable areKaidocarpumreferred to thePandaneæ, and such exogens asFicusandCinnamomum.

2.Tertiary.

4. TheUnartokseries. This is believed to be Eocene. It consists of sandstone, which appears on the shores of Disco Island, andpossibly at some other places on the coast. The beds rest directly and apparently conformably on the Upper Cretaceous, and have afforded only eleven species of plants.Magnoliais represented by two species,Laurusby two,Platanusby two, and one of these said to be identical with a species found by Lesquereux in the Laramie,[FR]Viburnum,Juglans,Quercus, each by one species; the ubiquitousSequoiasbyS. Langsdorfii. This is pretty clearly a Lower Laramie flora.

[FR]Viburnum marginatumof Lesquereux.

5. TheAtanekerdlukseries, consisting of shaly beds, with limestone intercalated between great sheets of basalt, much like the Eocene of Antrim and the Hebrides. These beds have yielded 187 species, principally in bands and concretions of siderite, and often in a good state of preservation. They are referred to the Lower Miocene, but, as explained in the text, the flora is more nearly akin to that of the Eocene of Europe and the Laramie of America. The animal fossils are chiefly fresh-water shells.Onoclea sensibilis, several conifers, asTaxitesOlriki,Taxodium distichum,Glyptostrobus Europæus, andSequoia Langsdorfii, and 42 of the dicotyledons are recognised as found also in American localities. Of these, a large proportion of the more common species occur in the Laramie of the Mackenzie River and elsewhere in northwest Canada, and in the western United States. It is quite likely also that several species regarded as distinct may prove to be identical.

It would seem that throughout the whole thickness of these Tertiary beds the flora is similar, so that it is probable it belongs altogether to the Eocene rather than to the Miocene.

No indication has been observed of any period of cold intervening between the Lower Cretaceous and the top of the Tertiary deposits, so that, in all the vast period which these formations represent, the climate of Greenland would seem to have been temperate. There is, however, as is the case farther south, evidence of a gradual diminution of temperature. In the Lower Cretaceous the probable mean annual temperature in latitude 71° north is stated as 21° to 22° centigrade, while in the early Tertiary it is estimated at 12° centigrade. Such temperatures, ranging from 71° to 53° of Fahrenheit, represent a marvellously warm climate for so high a latitude. In point of fact, however, the evidence of warm climates in the arctic regions, in the Palæozoic as well as in the Mesozoic and early Tertiary, should perhaps lead us to conclude that, relatively to the whole of geological time, the present arctic climate is unusually severe, andthat a temperate climate in the arctic regions has throughout geological time been the rule rather than the exception.

III.—MINERALISATION OF FOSSIL PLANTS.

The state of preservation of fossil plants has been referred to incidentally in several places in the text; but the following more definite statements may be of service to the reader.

I. Organic remains imbedded in aqueous deposits may occur in an unchanged condition, or only more or less altered by decay. This is often the case with such enduring substances as bark and wood, and even with leaves, which appear as thin carbonaceous films when the layers containing them are split open. In the more recent deposits such remains occur little modified, or perhaps only slightly changed by partial decay of their more perishable parts. In the older formations, however, they are usually found in a more or less altered condition, in which their original substance has been wholly or in part changed into coaly, or bituminous, or anthracitic or graphitic matter, so that leaves are sometimes represented by stains of graphite, as if drawn on stone with a lead-pencil. Yet even in this case some portion of the original substance remains, and without any introduction of foreign material.

II. On the other hand, such remains are often mineralised by the filling of their pores or the replacement of their tissues with mineral matter, so that they become hard and stony, and sometimes retain little or nothing of their original substance. The more important of these changes, in so far as they affect fossil plants, may be arranged under the following heads:

(a)Infiltrationof mineral matter which has penetrated the pores of the fossil in a state of solution. Thus the pores of fossil wood are often filled with calcite, quartz, oxide of iron, or sulphide of iron, while the woody walls of the cells and vessels remain in a carbonised state, or converted into coaly matter. When wood is preserved in this way it has a hard and stony aspect; but we can sometimes dissolve away the mineral matter, and restore the vegetable tissue to a condition resembling that before mineralisation. This is especially the case when calcite is the mineralising substance. We sometimes find, on microscopic examination, that even cavities so small as those of vegetable cells and vessels have been filled with successive coats of different kinds of mineral matter.

(b) Organic matters may be entirelyreplacedby mineral substances. In this case the cavities and pores have been first filled,and then—the walls or solid parts being removed by decay or solution—mineral matter, either similar to that filling the cavities, or differing in colour or composition, has been introduced. Silicified wood often occurs in this condition. In the case of silicified wood, it sometimes happens that the cavities of the fibers have been filled with silica, and the wood has been afterward removed by decay, leaving the casts of the tubular fibers as a loose filamentous substance. Some of the Tertiary coniferous woods of California are in this state, and look like asbestus, though they show the minute markings of the tissue under the microscope. In the case of silicified or agatized woods, it would seem that the production of carbon dioxide from the decaying wood has caused the deposition of silica in its place, from alkaline solutions of that substance, and thus the carbon has been replaced, atom by atom, by silicon, until the whole mass has been silicified, yet retaining perfectly its structure.

(c) The cavities left by fossils which have decayed may be filled with clay, sand, or other foreign matter, and this, becoming subsequently hardened into stone, may constitute acastof the fossils. Trunks of trees, roots, &c., are often preserved in this way, appearing as stony casts, often with the outer bark of the plant forming a carbonaceous coating on their surfaces. In connection with this state may be mentioned that in which, the wood having decayed, an entire trunk has been flattened so as to appear merely as a compressed film of bark, yet retaining its markings; and that in which the whole of the vegetable matter having been removed, a mere impression of the form remains.

Fossils preserved in either of the modes, (a) or (b), usually show more or less of their minute structures under the microscope. These may be observed:—(1) By breaking off small splinters or flakes and examining them, either as opaque or as transparent objects. (2) By treating the material with acids, so as to dissolve out the mineral matters, or portions of them. This method is especially applicable to fossil woods mineralised with calcite or pyrite. (3) By grinding thin sections. These are first polished on one face on a coarse stone or emery hone, and then on a fine hone, then attached by the polished face to glass slips with a transparent cement or Canada balsam, and ground on the opposite face until they become so thin as to be translucent. In most cities there are lapidaries who prepare slices of this kind; but the amateur can readily acquire the art by a little practice, and the necessary appliances can be obtained through dealers in minerals or in microscopic materials. Very convenient cutting and polishing machines, some of them quite small and portable, arenow made for the use of amateurs. In the case of exogenous woods, three sections are necessary to exhibit the whole of the structures. One of these should be transverse and two longitudinal, the latter in radial and tangential planes.

IV.—GENERAL WORKS ON PALÆOBOTANY.

In the text frequent reference has been made to special memoirs and reports on the fossil plants of particular regions or formations. There are, however, some general books, useful to students, which may be mentioned here. Perhaps the most important is Schimper’s “Traité de Paléontologie Végétale.” Very useful information is also contained in Renault’s “Cours de Botanique Fossile,” and in Balfour’s “Introduction to Palæontological Botany,” and Nicholson’s “Palæontology.” Unger’s “Genera et Species,” Brongniart’s “Histoire des Végétaux Fossiles,” and Lindley and Button’s “Fossil Flora,” are older though very valuable works. Williamson’s “Memoirs,” in the “Philosophical Transactions,” have greatly advanced our knowledge of the structures of Palæozoic plants. Lastly, the “Palæophytology” of Schenk, now in course of publication in German and French, in connection with Zittel’s “Palæontology,” is an important addition to manuals of the subject.

INDEX.

Acer,228.Acrogens,6.Agassiz, Prof.,16.Alaska, Flora of,245.Algæ, real and spurious,26,230.Amboy clays, Flora of,203.America, Cretaceous of,190.Angiosperms,6.Annularia,122.Anogens,6.Antholithes,132.Aporoxylon,25.Araucarioxylon,148.Araucarites,134.Archæocalamites,170.Archæopteris,77,85.Arctic origin of plants,221,238.Arthrophycus,30.Arthrostigma,67.Asterophyllites,78,122,170.Asteropteris,77,85.Astropolithon,30.Atané, Plants of,242,281.Atanekerdluk, Plants of,283.Australia, Palæozoic flora of,147.Tertiary flora of,217.Bauhinia,204.Bear Island,241.Betula,198.Bilobites,28.Bovey Tracey, Plants of,226.Brasenia,207.Buckland, Dr.,179.Buthotrephis,37.Calamites,77,123,166.Calamodendron,125.Cambrian flora,20.Canada, Erian of,103.Carboniferous of,110.Laramie of,209.Pleistocene of,227.Carbon in Laurentian,9.Carboniferous flora,110.Carboniferous, Climate of,138.of Southern Hemisphere,147.Cardiocarpum,82,153.Carruthers, Mr.,24,98,180.On modifications of modern plants,225,269.Carya,196.Cauda-galli fucoid,105.Caulerpites,29.Caulopteris,75,94.Clarke, Prof.,51.Climate, Causes of,247.Climate and plants,216,220,232.of Carboniferous,138.of Cretaceous and Eocene,216.of Devonian,47.of Early Mesozoic,178.Climate and plants of Laurentian,17.of Pleistocene,227,230.of Pliocene,223.Coal, origin of,117,139.Comparison of floras,272.Composite,266.Cone-in-cone,36.Coniferæ, Erian,78,96.Carboniferous,134,148.Mesozoic, etc.,181.Cope, Mr.,215.Cordaites,78,130,151.Corylus,213.Crepin, M.,99.Cretaceous, Flora of,190.Climate of,216.Croll on climate,252.Cromer, Plants of,224.Cycads, Mesozoic,178.Cyclostigma,157.Dadoxylon,96,134,148.Dawson, Dr. G. M.,52,210.Delgado, Prof.,26.Dendrophycus,33.Derby, Orville,53.Devonian flora,45.Devonian or Erian,107,279.Climate of,47.Dicotyledons, Cretaceous,192.Table of,192.Dictyolites,33.Dictyospongia,39.Disco, Exotic plants at,256.Flora of,245,282.Drepanophycus,39.Drosera,228.Dunvegan beds,244.Eocene, Flora of,208,214.Climate of,216.Eophyton,31.Eopteris,72.Eozoon of Laurentian,9.Equisetum,176,230.Erian flora,45,279.Climate of,47.Erian or Devonian,107.Ettingshausen, Dr.,187,215.Exogens, Cretaceous,192.Tertiary,213,224.Fagus,196,197.Ferns, Erian,72.Carboniferous,126,171.Fructification of,128.Stems of,90,129.Tertiary,212.Filices,72,126,171.Flora of Cambrian,26.of Carboniferous,110,274.of Cretaceous,190.of Early Mesozoic,175.of Erian,45,279.of Jurassic,177,186.of Laramie,209.of Laurentian,8.of Miocene,220,223.of Modern,219.of Permian,274.of Pleistocene,223,227.of Tertiary,191,208,214,219.Fontaine, Prof.,130,176.Fontinalis,230.Fort Union beds,210.Fucoids,27.Gardner, Mr. Starkie,212.Geinitz, Dr.,174.Geological formations, Table of,4.Glossopteris,147.Glyptodendron,25.Glyptostrobus,194.Goeppert, Dr.,99.Grant, Col.,36.Graphite from plants,8.Gray, Dr., Origin of floras,223,237.Greenland, Climate of,216.Fossil flora of,247.Gulielmites,35.Gymnosperms,6.Haliserites,39.Hartt, Prof.,53.Heer, Dr.,108,181.Helderberg period, Sea of,250.Heterangium,77.Hicks, Dr.,21.Hunt, Dr. Sterry,13,143.Huxley, Prof.,53.Hymenæa,204.Insects, Erian,83.Juglans,196.Jurassic flora,177.Kainozoic flora,191,208,214,219.Kidston, Mr. R.,128,273.King, Mr. Clarence,211.Komé, Plants of,242,281.Laramie flora,209,215.Laurentian plants,8.Laurentian, Climate of,17.Laurophyllum,193.Laws of introduction of plants,237,266.Leda clay, Flora of,232.Lepidodendron,120,156,162.Lepidophloios,121,157,165.Leptophleum,157.Lesquereux, Mr. L.,169,214.Licrophycus,30.Lignitic series of America,208.Liquidambar,197.Liriodendron,199.Lower Carboniferous flora,277.Logan, Sir W.,48.Lyell on climate,249.Magnolia,200.McConnell, Mr.,209.McNab, Prof.,169.Megalopteris,76.Megaphyton,129.Mesozoic flora,175.Climate of,178.Migrations of plants,240,245.Miller, Hugh,98.Miocene flora,220.Miocene, Supposed,242.Modern flora,219.Modern plants, how modified,269.Modifications of plants,266.Nathorst, Dr.,26,196.Nematodendreæ,25.Nematophycus,23.Nematophyton,21,22,42.Newberry, Dr.,200,203,214.Newfoundland, Fossil plants of,242.Newton, Mr.,52.Nicholson, Dr. A.,20.Niobrara series,243,246.Noeggerathia,130.Northern origin of plants,238.Origin of plants,237.Orton, Prof.,51.Pachytheca,21.Palæanthus,205.Palæochorda,30.Palæophycus,30,38.Palæozoic floras compared,273.Palms,188,194.Pandanus,188.Patoot beds,282.Peach, Mr.,98.Petroleum, Origin of,56.Phymatoderma,29.Plants, Classification of,6.Platanus,198.Platyphyllum,74.Pleistocene climate,227,230.Pleistocene flora,223,227.Pliocene climate,223.Podozamites,178.Poles, Supposed change of,248.Populus,191,228.Potamogeton,229.Potentilla,228.Protannularia,21.Protichnites,27.Protophyllum,199.Protosalvinia,52.Protostigma,20.Prototaxites,21.Psaronius,93.Psilophyton,64.Ptilophyton,62,86.Quercus,197.Rhizocarps,48.Rill-marks,33.Rusichnites,28.Saccamina,57.Salisburia,180.Salter, Mr.,98.Salvinia,54.Saporta, Count de,26,193.Saportea,57.Sassafras,199.Scalariform tissue,70.Schimper, Dr.,116,169,208.Scolithus,30.Scottish Devonian,98.Sequoia,181.Shrinkage cracks,33.Sigillaria,71,112,154.Southern Hemisphere,217,273.Carboniferous in,147.Tertiary in,217.Sphenophyllum,61,122,171.Spirophyton,38.Spitzbergen,241.Sterculites,193.Sternbergia,137,152.Stigmaria,115.Stur, Dr., on Sigillaria,116.Symphorocarpus,214.Syringodendron,156.Syringoxylon,82.Table of formations,4.Tasmania, Fossil plants of,217,246.Tasmanite,57.Tertiary period, Flora of,191,208,214,219.Tertiary of Australia,217.Thallogens,6.Thomas, Mr.,51.Thuja,213,229.Time, Geological,5.Trapa,196.Tree-ferns,90,129.Triassic flora,176.Trigonocarpum,136,153.Tyndall, Prof.,138.Ulrich, Prof.,57.Unartok beds,281.Ursa stage of Heer,108,241.Walchia,134,138.Ward, Mr. L. T.,192,212,215.Wethered, Mr. E.,52.White, Dr.,215.Williams, Prof.,51.Williamson, Dr.,26,31,71,167.Williamsonia,188.

Back to Index Next