Imagens das páginas

thulate and obtuse; the midrib is large at the base, and gradually contracts to the apex; the secondary veins are distinct, parallel near the base, but soon afterwards become oblique and regularly anastomose. In Brongniart's figures, as well as in the one subsequently copied by Goppert, and also in their descriptions, the veins are mentioned as being only reticulate near the mid rib, becoming simple or furcate as they approach the margin: a careful examination of numerous specimens has convinced me that the veins regularly anastomose between the midrib and margin, as shown in the figure (PI.VI. fig. la.), and in Brongniart Veg. Foss. PI. 62. f. 1. A."

Locality.—Newcastle coal mines, New South Wales.

Pecopteris australis. (PL VII. fig. 1, 2. 2a.)

"Frond bipinnate; pinnae oblique, alternate, rather distant; pinnulae thin, falcate and rather obtuse, oblique and somewhat incurved, more or less adnate to the rachis, and sometimes decurrent, dilate at the base, or auriculate; midrib slightly flexuous, evanescing towards the apex; veins oblique, bifurcate, or dichotomous.

"This fern belongs to the neuropteroid division of Pecopteris, and bears much greater resemblance to the P. Whiibiensis and P. tenuis of the oolitic series of England, than to any other species described by Brongniart as occurring in the coal-measures. The frond appears to have been bipinnate, with oblique alternate pinnae; the pinnulae are rather thin, somewhat falcate and obtuse, the margins of which vary slightly in form, being either sinuous or entire, according to their position on the frond. This fern bears considerable analogy to the Pecopteris Lindleyana, figured in Professor Royle's Plustratiom.

Locality Jerusalem basin, Van Diemen's Land.

Pecopteris (PI. VI. fig. 2, 3, 4.)

"Frond pinnatifidly bipinnate, or flabellate ? pinnae linear, elongate, acuminate; pinnula; opposite, approximate, adnate, ovate obtuse, entire; veins nearly obliterated.

"There is some difficulty in assigning this species to the proper genus, in consequence of all the specimens I have examined being imbedded in a coarse sandstone, so that the venation, with the exception of a slight central depression indicative of a mid rib, is nearly obliterated. With some care, however, in detaching the matrix from the pinnula?, I have been enabled to trace what appears to be a slight radiation in the form of the secondary veins, resembling that generally found in Odontopteris (whence the specific name): this may prove to be deceptive, and other specimens may perhaps better elucidate this view.

"The general contour of this fern (PI. VI. f.3.) somewhat resembles a single pinna of Neuropteris conferta Sternb.; but the pinnula} are more oblong, and the terminal one more acuminate; but it still more closely approaches in form a pinna of Odontopteris Permiensis, a fern described from the Permian system, in the work on the Geology of Russia, by R. J. Murchison, Esq.

"Presuming, on the other hand, that it forms a portion of a flabellate frond, a pinna, of which a drawing only has been seen, bears considerable affinity, as to its mode of furcation, to the recent species Gleichenia flabellata, and under this point of view might be associated with the genus Laccopteris Presl., should the venation prove to be the same."

Locality. —Jerusalem basin.

"A figure has also been given with more lanceolateshaped pinnula?, which is probably only a variety of this species.

"Besides the above, the author of this volume has brought to England some drawings of other ferns from the coal-basin of Jerusalem, which it has been considered advisable not to allude to, as the original specimens have not been examined, which are in the collection of William Breton, Esq., at Launceston, Van Diemen's Land. It is desirable that the local geologists may be stimulated to make a good collection of these fossil plants, so that a careful comparison may be instituted with those of Northern Europe, as well as with the species from the Indian deposits."

Zeugophyllites Brongniart. — Family uncertain. Z. elongatus. (PI. VI. fig. 5, 5a.)

"Stem—? leaves petiolate, oblong elongate, entire, truncate, and slightly thickened at the base; veins distinct, equal, parallel.

"The specimen figured has been provisionally referred to Zeugophyllites Brong., as it agrees tolerably well with the characters assigned to the leaves of that genus. These leaves were probably sessile, or even amplexicaul, as might be inferred from their slightly thickened base, and pinnately arranged, at short distances, along a common stem, after the manner of the foliation of Schizoneura Schimper, Convattarites Brong., to which genus our species offers some resemblance; the leaves, however, in Schizoneura have fewer veins, and appear to have been somewhat carinated." Locality. — Jerusalem Basin, Van Diemen's Land.

Phyllotheca australis Brongniart, Prod.

"Stem simple, straight, articulate, smooth, or striate; articulations surrounded by sheaths; sheaths

[ocr errors]

longitudinally sulcate, foliaceous; leaves of the sheath long, linear, pointed.

"This remarkable plant, of which numerous traces remain in the shale, containing also Glossopteris Browniana, was first described by .Ad. Brongniart. It has the general aspect of Catamites, but more strongly resembles Equisetwn in the peculiar arrangement of the sheaths at the articulations; which, however, are furnished with long linear leaves, instead of being terminated by short, simple, and conical teeth, as in the ordinary sheaths of Equisetum; the leaves are either straight, more frequently oblique, or even reflected, and about twice the length of the sheath, which is longitudinally sulcated in the intervening spaces. The foliaceous appendages to the sheath in this plant — a character not found in any species of Equisetum — has induced Ad. Brongniart, notwithstanding the general analogy in external form, to consider it as entirely distinct from that genus, and more nearly related to the other genera with verticillate leaves, as Aster ophyllites, &c, than to the true Equisetacea>."

Locality—Newcastle coal mines, New South Wales

"In reviewing the few species of the ancient flora that have been hitherto collected from the carboniferous deposits of Australia, including therein the fossil plants from the basin of the Hunter, in New South Wales, and those from the Jerusalem basin, in Van Diemen's Land, we at once perceive the interesting fact, that although limited as the species are in number, there is no trace of any of those remarkable genera so characteristic of, and so abundant in, the strata of the European and American coal-fields, such as Lepidode?idron, Sigillaria, Stigmaria, Catamites, or Coniferai."

"The basins themselves, if indeed contemporaneous, appear to be characterised by a distinctly localised flora ; no species, as far at least as our observations have extended, being found common to the two deposits. The basin of the Hunter contains Phyllotheca australis, Glossopteris Browniana, and some other species; in that of Jerusalem, in Van Diemen's Land, are found three or four species belonging to the genera Sphenopteris and Pecopteris, and one to Zeugophyttites, these being associated with some large fragments of stems, too imperfect to be defined.

"In comparing, therefore, the whole of the species at present known, from these deposits, with the coal plants of Europe, there appears, indeed, to be but few, if any, analogical forms, although the equisetoidlooking Phyllotheca may probably be considered as the representative of the Calamites of the northern deposits; while, on the other hand, its congener, the Glossopteris Browniana, is a fern so entirely different from any of those that are found in the carboniferous periods of the northern hemisphere.

"Among the fossil plants collected from the Jerusalem basin, we find the interesting genus Zeugophyllites, and certain forms of Pecopteris, one of which is closely allied to an oolitic species, and another having strong resemblances to an Odontopteris from the Permian system of Russia.

"These few observations partly lead us to infer that the flora of the southern hemisphere was perfectly distinct in its facies from the northern, at the carboniferous period; just as, at the present time, the modern flora of the same continent presents a striking difference to that of other portions of the globe; and this appears to be the more remarkable, as the species constituting the fauna of the Australian ocean, anterior to that period, contain many forms which, if not

« AnteriorContinuar »