history of the American flora, to discover through the plants of the tertiary the various elements of which it is composed; the time will surely come when we shall be acquainted with the true characters of the different floras and with the history of their formation." "You very correctly remark that the examination of the tertiary flora of Oregon and Vancouver shows that the flora is nearly related to the European flora of the same epoch. Among your species, we find some which are considered as particularly characteristic of our tertiary; viz. the species of Cinnamomum. Cinnamomum crassipes, Lsqx., is hardly distinguishable from C. Rossmaesleri, Heer. It is a pity that the point of the leaf is wanting; it would at once decide the matter, showing whether the nerves ascend to the point or disappear below it, as is the case in C. lanceolatum, which is also very similar.-Cinnamomum Heerii, Lsqx., is not so certain in its identity. At any rate, it would better agree with C. polymorphum than with C. Buchii, which is broader just above its middle. What makes me doubtful here, is that the fine nervules emerge at an acute angle, while in Cinnamomum they have a somewhat different direction. Perhaps your drawing in this is not quite correct, for in every other respect, the leaf as far as it is preserved would well agree with our C. polymorphum. As to Planera, I perfectly agree with you, that it is not possible to separate it from P. Ungeri. Salix Islandica, Lsqx., in its form and general outline resembles our Salix macrophylla. But if the nervation is rightly marked, your leaf cannot belong to that species. In Salix macrophylla, as in the willows generally, we have, besides the percurrent secondary nerves united near the margins, some other shorter intermediate secondary nerves, which emerging at an obtuse angle from the medial nerve, extend to the nearest secondary nerve either above or below and join with it. In Salix macrophylla these shorter secondary nerves are very close together. But in your drawing I see only secondary nerves running nearly to the margins, and if it is correct your leaf does not belong to a Salix. The name you give to this leaf (Salix Islandica) is peculiar. Your leaf could not have been brought from Iceland? I received from Copenhagen a very interesting collection of the tertiary flora of Iceland, and among the leaves there are some willows which can not be distinguished from our Salix macrophylla. Your mapleleaf appears to be somewhat toothed on the margins. If it is so, it would not belong to Acer trilobatum. However, it is not well enough preserved for ascertaining its true species. The place of your Salisburia is perfectly right, since a Salisburia, S. adiantifolia, has been found at Sinigaglia, which place, with Stradella and Guarenne, belongs without doubt to the upper strata of Eningen and consequently to the upper Miocene. Your leaf, Pl. 1, fig. 1, Quercus Benzoin, Lsqx., is the most interesting of your species, as it seems so perfectly to agree with Oreodaphne Heerii, Gaud.,. that there is scarcely a doubt of the identity of the two species. But your leaf does not show the small holes or depressions marked in the axils of both the inferior secondary nerves. You probably did not remark them. I beg you will again examine the specimen, and I feel confident that you will find there a small depression; if so, the identity of species is proved. The form and nervation of the leaves are truly peculiar and already suffcient for identification. Oreodaphne Heerii, Gaud., has been abundantly found in the upper Miocene and lower Pliocene of Italy, but never till now on this side of the Alps. It much resembles Oreodaphne fætens of the Canary islands. You will find it figured in the paper of our friend Gaudin, which I send you. A second Italian leaf is probably your Quercus Gaudini, Lsqx.: I have at least seen one very like it in Gaudin's new treatise, which is not yet published, and I have not the plates on hand just now. I would take your leaf, Pl. 1, fig. 2, for Ficus multinervis if the secondary nerves were united in their arched points. This is not marked in your drawing. These secondary nerves are somewhat too straight to belong to Quercus neriifolia" "From these few species, we can already see a near relation between the American tertiary flora and ours; and in several species, this relation passes to a true identity. We may add to your species Glyptostrobus Eningensis, Br., and Taxodium dubium, Sternb. In the U. S. Exploring Exped., during the years 183839-42, under the command of Ch. Wilkes, Geol., Atlas, Pl. 21, by Dana, there is a plate with figures of leaves from Frazer river, and among them, the two above named species are easily identified. Fig. 11 and 15 may belong to Caprinus Gaudini; but probably the margin of the leaf is not rightly drawn. Fig. 12 is like Rhamnus Rossmaesleri or perhaps a Smilax. These plants therefore confirm our conclusion." "Another important deduction may be drawn from your plants, viz. that in the American tertiary flora, there are some Asiatic types which no longer belong to the American continent, namely Cinnamomum and Salisburia; and further an Atlantic type, the Oreodaphne. There is still an Oreodaphne in America; but the fossil species is related to 0. fœtens of the Canary Islands. A third conclusion taken also from the same plant is that fan-like Palm trees were growing at the same time in the same latitude with Sequoia and Taxodium, and that therefore we must admit of a warmer climate in North America at that epoch. And now from this fact that a flora of the same character occurred at the tertiary epoch in Northern Europe and North America, it follows that both parts of the earth had a like warmer climate. It is a new and very important confirmation of the Atlantis! the second that I have received this month. The first was given me by the collection of tertiary fossil plants from Iceland in which I found a Liriodendron (leaves and fruit) very like L. tulipifera, L., with six species of Pines, of which one much resembles Abies alba. With this, there are leaves of Alnus, Betula, Salix, Araucaria, Acer, Sparganium, Equisetum, &c., and in truth, species which agree perfectly with those of the tertiary flora. You will find in the general part of my Flora of the Tertiary, where I give a general survey of the tertiary flora of Europe, a detailed account of these leaves of Iceland, and also of some other parts of Europe from which I have received large collections."" "Your views of the gradation of the flora of North America agree perfectly with what we find in Europe. This led me to believe that the plants of Nebraska belong to the tertiary and not to the cretaceous formation. It is true that I have seen only some drawings which were sent to me by Messrs. Hayden and Meek; but they are all tertiary types. The supposed Credneria is very like Populus Leuce, Ung., of the lower Miocene, and the Eltinghausiana seems hardly rightly determined. Besides it is a genus badly founded, and which has as yet no value. All the other plants mentioned by Dr. Newberry belong to genera that are represented in the Tertiary and not in the Cretaceous. And it is very improbable that in America the cretaceous flora has had the characteristic plants of the tertiary; and this would be the case if these plants did belong to the Cretaceous."* To this most interesting letter of Prof. Heer, I can only add a few words of explanation about his remarks on my species. I owe to the kindness of Dr. John Evans the privilege of still having his specimens in my possession; I was therefore enabled to again examine the only specimen of the leaf which according to Prof. Heer is referable to Oreodaphne Heeri, Gaud. Though the specimen is one of the best preserved of the collection, there is no trace of the mentioned pimples or depressions at the axils of the basilar secondary nerves as marked in the figure of M. Gaudin's memoir. One leaf agrees in its general outline and by its primary and secondary nervation with an Oreodaphne. But the secondary intermediate nerves are large, deeply marked, and perpendicular to the primary one; and the tertiary nervules are also mostly perpendicular to the secondary ones, well marked and mostly percurrent. This last character especially would separate our leaf from the genus Oreodaphne and put it rather with the oaks.-About Salix Islandica which I referred with *Prof. Heer had not seen, when he wrote this, the paper by Messrs. Meek and Hayden in our last volume (p. 219), in which it is shown that the beds containing these leaves occur beneath thick strata characterized by Baculites, Ammonites and other fossils of the Cretaceous. Dr. Newberry has also identified similar leaves from beneath the Cretaceous of New Jersey (collected by Prof. G. H. Cook), and others from New Mexico; so that, if the leaves are tertiary our Cretaceous is abolished.-EDS. doubt to Salix macrophylla, it is not possible to say any thing definite. The leaf is printed on coarse shaly sandstone and the secondary nerves are scarcely marked. It is from the general outline of the leaf and its denticulation, that I had to take the characters. The name Islandica was accidentally given as indicating a high latitude for a species of willow with such large leaves. It is truly a curious coincidence that Prof. Heer received from the tertiary of Iceland specimens of a species related to or perhaps identical with ours. Cinnamomum Heeri, Lsqx., is a true Cinnamomum in every character; but Quercus mullinervis, figured Pl. 1, fig. 2, has apparently the points of the nerves arched and united, and is truly comparable with Ficus multinervis and perhaps identical with it. The specimen figured in Prof. Heer's flora is very poor, and our own is badly broken, and the points of the nerves are scarcely discernible. ART. XI.-Geographical Notices. No. VIII. RESULTS OF THE RECENT EXPLORATIONS IN AUSTRALIA.— We translate from Petermann's Mittheilungen, April, the following important survey of the results obtained in the recent explorations of Australia. It is principally based on official and authentic reports relating to the following expeditions: 1. Stephen Hack's Researches in the Gawler Mts., and at Lake Gairdner, 1857. 2. Major Warburton's Journey to Lake Gairdner, June and July, 1858. 3. B. Herschel Babbage's expedition to the region between Lake Gairdner and Lake Torrens, 1858. 4. Stuart's, Babbage's and Warburton's explorations north from Lake Campbell. The article in Petermann is accompanied by a map of Australia between 133° and 138° long. east from Greenwich, and between 30° 30' and 33° S. lat. In order to obtain a clear insight into the advantages which have been gained by the numerous expeditions, we shall separately consider their scientific and practical results. In regard to the first view, the question arises about the unknown interior of the Continent. Although the newly explored area comprises only four degrees of longitude and as many of latitude, not extending yet one third of the distance between Spencer's Gulf and the Gulf of Carpentaria, there is new reason to assume, that the interior formation and condition of Australia have a far more varied character, than has been generally supposed. It is shown, that there is no uniform desert of stone and sand, but a SECOND SERIES, VOL. XXVIII, No. 62.—JULY, 1859. succession of tracts of lands useless and useful, part already inhabited and part capable of being so. The lake district west of the Torrens Basin is in itself a very interesting region which has given rise even in Australia to many hypotheses on the origin of the continent. The salty ingredients of the soil, the salt water lakes, and the sea-shore-like plains west of the Torrens Basin described by Stuart, were used as arguments for the supposition that this part of Australia had been lifted out of the sea in a comparatively recent period only; that in its place an arm of the sea formerly existed, which perhaps connected Spencer's Gulf with the Gulf of Carpentaria, whereby Australia was divided into two parts. These hypotheses, though pleasantly drawn out, must however be considered useless and hasty, as by a close scientific physical examination they are as likely soon to be refuted as confirmed. Even Babbage's calculations of his barometrical observations are still wanting and with them the basis most necessary to a physical examination of the country. However, in relation to height, we may assume as tolerably certain, that from Spencer's Gulf in the direction from N. to Ñ.W., plains extend into the interior elevated but little above the level of the sea and separated from each other by plateaux. The Torrens Basin with its lagoons and coast plains forms one of these low tracts, a second one is represented by that series of lakes, which commences with Lake Dutton and ends on the other side of Lake Younghusband in several swamps and sloughs; a third is formed by the great sinkings of Lake Gairdner and its environs. Major Warburton believes that Lake Gairdner is situated below the level of the sea. If this be true, it must also be the case with the Great Salt Lake and the other adjacent lakes, as we find in Babbage's Reports no intimation. of any difference in their height. Without expressing any definite opinion we will only mention, that Gregory, in his previous expedition from Moreton Bay to Adelaide, crossed the Torrens Basin and found by barometrical means that this basin was situated decidedly above the level of the sea. But the Torrens Basin has there, as the most recent travellers in Australia affirm, its greatest depth. Warburton's opinion therefore remains for the present at least improbable. The area of the discovered lakes is not inconsiderable, as a comparison with the Lake of Constance shows (Area 207 Eng. or 975 Germ. sq. m.). By a calculation based on sketches of charts we find Lake Gairdner in the extent given on the chart 2807 E. or 132 G. M. 351 " แ 165 2.7" |