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an account of some footprints of Batrachians and Reptiles. Next follows the CONCLUSION, containing a synoptical table showing the stratigraphical positions of all the species noticed in his three parts, and another, their distribution in time; and then, general observations on the relations of the species, and some stratigraphical observations.

7. The Phosphate Rocks of South Carolina: their History and Development; by FRANCIS S. HOLMES, A.M., of Charleston, S. C. 88 pp. 8vo. Charleston, 1870.--This Report is evidently intended as a popular exhibition of the resources of South Carolina in phosphatic deposits, and of some of the companies engaged in' mining them. The author advocates the untenable opinion that the phosphatic material was originally an Eocene formation, and that what occurs now elsewhere was washed out of the Eocene marl into its present position; the multitudes of sharks teeth in the Eocene indicating in his view that sharks and other fishes were the main source of the phosphoric acid.

III

8. Geognostisch-mineralogische Fragmenta aus Italien. Theil: Die Insel Elba; von Prof. G. voм RATH, in Bonn. pp. 591-732, from the Zeitschr. d. deutschen geol. Ges., 1870, with two plates.-Like all of Prof. von Rath's papers this is a very thorough treatise, both geologically and mineralogically. The plates contain figures of rare forms of the species Quartz, Orthoclase, Beryl, Tourmaline, Petalite (Castor), Sphene, and Ilvaite; besides a map of the Island of Elba.

9. Lophiotherium sylvaticum.—Dr. Leidy has so named a species of fossil mammal, based on a portion of the lower jaw found by Prof. Hayden on Henry's Fork of Green river, Wyoming.— Acad. N. Sci. Philad., Nov. 15, 1871.

10. Auchenia Californica.-Several bones obtained by Prof. J. D. Whitney, and labeled "under Table mountain near Shaw Flat, Tuolumne Co., California," have been referred by Dr. Leidy to a new and large extinct species of Lama and named as above.—Id.

11. Protohippus of Leidy.--Dr. Leidy observes that the genus Hippidion of Owen, instituted in his paper on the Fossil Equines from Central South America (Phil. Trans. 1869), is essentially that established by him in 1858 under the name Protohippus.-Id.

12. Fossil Reptiles of the Cretaceous of Kansas.--Prof. Cope has recognized among specimens received recently from Kansas, Elasmosaurus platyurus Cope, Polycotylus latipinnis Cope, Liodon proriger Cope, and three new Liodons, which he names L. ictericus, L. Mudgei, and L. dyspelor. The last was allied to Mosasaurus Brumbzi, but was very much larger.-Id. for Dec. 6.

13. General Chart showing the amount and yield of Mineral fuel in Austria in the year 1868, by FR. FOETTERLE. An interesting Chart published by the Geological Reichsanstalt of Austria, under the title, Uebersichts-Karte des Vorkommens der Production und Circulation des mineralischen Brennstoffes in der Oesterreichischen Monarchie im Jahre 1868.

AM. JOUR. SCI.-THIRD SERIES, VOL I, No. 3.-MARCH, 1871.

14. Rhododendrea Asia Orientalis: a paper by Maximowicz, recently issued (1870) as the 9th fasciculus of the 16th volume of the Memoirs of the Imperial Academy of Sciences of St. Petersburg; illustrated by 4 plates, imp. 4to. In the commencement of this elaborate and very interesting article, Maximowicz explains that the name Rododendrea is preferred to Rhodorea because the genus Rhodora is a mere quasi-abnormal form of a section of Rhododendron, taking this genus, as he does, in the most enlarged sense. Also that the characters of scaly and not scaly buds is not completely available, as was thought, for dividing the groups into two tribes as Klotzsch proposed. We have been accustomed to use this character in a subordinate way, when it is very valuable, aware that both modes occur in some genera, such as Vaccinium. The main distinction between his Phyllodocea and his Eurhododrendreæ is that of the seed, with a close testa in the former, scobiform in the latter. Among the genera of the former he ranks Rhodothamnus, founded on Rhododendron Chamacistus. The point which most nearly concerns us is that, notwithstanding the Californian species which we regard as uniting them, Maximowicz keeps up both Bryanthus and Phyllodoce, the former of Steller's original plant only, the corolla of which he newly describes as "ad basin 4-partita, horizontaliter patens." He also reclaims the genus for Steller, and states that Pallas had done so before him, that Gmelin had copied name and character verbatim from Steller, but without mentioning him at all. As to the genera, upon a review of the question under all the light now thrown upon it, we still think that the union proposed is likely to be maintained.

The name Loiseleuria is kept up,-although the plant was the original Linnæan Azalea,-and with sufficient reasons of history and convenience, which ought here to overbear the rule; for it is impracticable at this day to dissociate the name Azalea from the shrubs which every one knows under that name.

Of Menziesia Maximowicz recognizes six species; that is, he holds to the distinctness of our eastern M. globularis from the north-western M. ferruginea (but the characters seem to us insufficient and evanescent), finds a better distinction for the cognate Japanese species in its pentandrous flowers, and has three more apparently well-marked Japanese species.

Tsusiophyllum, of a single Japanese species, is an interesting new genus between Menziesia and Rhododendron, distinguished by its narrow tubular corolla, trimerous pistil, and longitudinally

dehiscent anthers.

Rhododendron, the great genus of the group, is disposed under eight sections. Four of these are of the terminal-flowered series, all but the last of which make the innovations from separate buds: 1. Osmothamnus, DeCandolle's genus, to which R. Lapponicum, and the two Alpenrosen, with some related species, are added. Eurhododendron, comprising the typical species, under four subdivisions. 3. Azalea with annual leaves, answering, with some exceptions, to that genus as admitted by DeCandolle. To a group

2.

of this subgenus, otherwise all Chino-Japanese, belongs R. Rhodora Don. 4. Tsusia, of which the so-called Indian, but really all Chino-Japanese Azaleas of our conservatories are the representatives, in which the innovations come from the same terminal buds with the flowers, and the leaves are less deciduous.

The lateral-flowered series consists of those which bear single or sometimes geminate flowers from lateral scaly buds. 5. Keysia Nutt. is formed for a single evergreen Himalayan species. 6. Rhodorastrum, with annual leaves and lateral innovations has R. Dauricum for its principal representative. 7. Azaleastrum, known from the last by its almost rotate corolla, comprises our western R. albiflorum Hook., and one or two Chino-Japanese species. 8. The anomalous group Therorhodion, with similar corolla, but cleft to the base on the lower side, the innovations extending into a foliaceous bracteate raceme, consists of R. Kamtschaticum, which reaches Alaska, and R. Redowskianum.

The 8th decade of Diagnoses of new plants of Japan and Mandshuria, by the same author, reprinted from the Academy's Bulletin, of the autumn of 1870, is of interest as containing a key to the species of Eleagnus, the characters of a new Iris which Miquel had taken for our I. cristata, a Triosteum which hardly differs from T. perfoliatum, and a Maudshurian and a Japanese species of Nabalus.

A. G.

15. Flora Australiensis.—The fifth volume of this great Colonian Flora, by Mr. Bentham, assisted by F. Müller, issued toward the close of 1870, has just been received. It comprises the last orders of Monopetala, from Myoporinea to Plantaginea, the Labiata being the largest family, and the Apetala from Phytolaccacea to Proteacea; the latter being of course by far the most important family, and occupying almost half of the present volume of 584 pages. In connection with this we may note the reception of the 6th volume of Ferdinand de Müller's Fragmenta Phytographia Australia (Melbourne, 1867-1868,) containing characters of new species and genera, revisions of various groups, etc., illustrated by lithographic plates of some of the more interesting plants; the present volume mainly devoted to Monopetala and to Proteaceae, and issued in advance of the corresponding portion of the Flora Australiensis. Thanks to two such indefatigable laborers, Australia may soon boast of a noble and unrivalled completed Flora.

A. G.

16. Marsilia and Pilulario, revised by A. Braun.-The Monatsbericht of the Berlin Academy of Sciences for August last, from p. 653 to p. 754, is occupied by Prof. Braun with a detailed account of these genera, upon which he has previously published the results of prolonged investigations. His present account is summed up in a tabular view or key to the species of both genera (in German) followed by a systematic arrangement and revision, with full synonymy, habitat, etc. The species of Marsilia now amount to 53, of which 9 are North American; and of Pilulariæ to 5, of which there is one, very little known, in the United States, certainly in Arkansas, probably in Georgia.

A. G.

III. ASTRONOMY.

1. Solar Eclipse of Dec. 22.-We copy the following article on the eclipse from Nature, the excellent scientific weekly under the editorial direction of the astronomer, Mr. Lockyer, and published by MacMillan & Co. London, and 63 Bleecker St., New York.

Mediterranean Eclipse, 1870; by J. NORMAN LOCKYER.-Cloud in Sicily, cloud in Spain, cloud in Africa. Such at first sight might seem to be the only result of all the observations made on the eclipsed sun of 1870.

But, after all, has the oracle been silent? I think not. Dare we, however, say that the great problem of the Corona, that one among the many still outstanding difficulties which the eclipse was invoked to settle, is settled? This, perhaps, would be saying too much, but still, I think, a step in advance has been made. The oracle has spoken darkly, perhaps, but it has spoken.

Let me endeavor to put the question as it stood a few weeks ago as briefly as possible.

Beginning the story some few years back we find the corona, a halo of white light around the moon, with a height sometimes represented as equal to the moon's diameter, sometimes more, sometimes less, with a border à discrétion,—so much did the drawings vary-regarded as the solar atmosphere.

Some thought the red prominences to be mountains, other observers called them clouds.

The polariscope was brought up with a view of determining whether the corona shone by reflected light or not. The result of this new method of observation was doubtful.

In the Indian eclipse of 1868 M. Janssen, by means of the spectroscope, still another aid, determined that the prominences were masses of hydrogen gas, but there was no final word about the corona. Major Tennant observed that its spectrum was continuous. Later in the same year Dr. Frankland and myself approximately determined the pressure of the prominence gases by means of a new method and laboratory experiments, and at once stated our conviction that the extensive corona, which had been depicted and represented by Kirchhoff and others to be the solar atmosphere, must be something else. This was our idea. I cannot quote our words, for I am writing in Venice and have no copies of our paper with me. In the American eclipse of 1869 the problem was advanced considerably, perhaps even more considerably than we can yet form an idea of, writing as we must still do doubtfully. I do not refer to the drawings, for they varied considerably, but to the observation that the light of the outer corona, like that of the prominences, gave a bright-line spectrum. But as at least some of the observers gave positions doubtfully, "near C" and "near E," I thought that the explanation was still possible which regarded the corona as of terrestrial origin; that is, which assumed it to be an appearance due to the presence of light in our own atmosphere. The problem was one of such difficulty that there seemed a possibility that, by some unexplained cause, some of the solar light might be diffused and beat

out of its course, and then mixing up with the light of the chromosphere, give us a sort of continuous spectrum, with the hydrogen bright lines superposed upon it; in other words, that as the eye perceives a bright, irregular region or glare around the uneclipsed sun, an effect due to our atmosphere, so also the eye might perceive a bright, irregular region or glare around the uneclipsed chromosphere during eclipses, due also to our atmosphere.

One word here about the Chromosphere, the name I have given to the bright-line-giving region outside the photosphere. It has long been clear that the spectroscopic method of observing it when the sun is not eclipsed is not totally effective; that is to say, that we only see a percentage of it-perhaps only a relatively small percentage-but the glowing prominences, that is, those in which there is no evidence of the rapid motion of ejection from the sun, the ejection taking place at all angles from the line of sight, afford evidence that there is probably a layer of cooler hydrogen susceptible of being rendered visible above the ordinary level. Now as these prominences may be 5' high, it is not unreasonable to suppose that the chromosphere may even extend to that distance, or even a little beyond it.

Hence it was that in the Instructions to Observers, drawn up by Prof. Stokes, and myself, and approved by the organizing committee for this 1870 eclipse, it is stated that—

"THE PRINCIPAL OBJECT to be obtained is to determine whether it is possible to differentiate the outer layers of irregular outline and the streamers (of the corona) from a stratum, say some 5' or 6' high round the sun, which may possibly be the limit of the gaseous envelopes above the photosphere."

The spectroscopic observers, therefore, were enjoined

α. "To determine the actual height of the chromosphere as seen with an eclipsed sun; that is, when the atmospheric illumination, the effect of which is doubtless only partially got rid of by the Janssen-Lockyer method, is removed. If the method were totally effective, the C line, the line of high temperature, should hardly increase in height: but there can be little doubt that the method is not totally effective, so the increase in height should be carefully noted."

b. "To determine if there exists cooler hydrogen above and around the vividly incandescent layers and prominences."

And the polarisers

"To examine a detached and selected part of the corona about 6' from the limb of the sun, and say about 8' in diameter."

Having got so far, it may be here stated that of the three means of attack, namely, the spectroscope, the polariscope and telescope, and naked eye observations, the spectroscopic method, under certain circumstances, might have been by far the most doubtful, the polariscope method coming next.

With regard to the spectroscopic observations, if we assume that no light whatever is received by and from our own atmosphere, the observations would be easily translated. A pure continuous

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