certain distinctions, so that their apparent value in the scheme exceeds their absolute value in nature; that names and groups are, in some degree, matters of usage, of comity, and of convenience, we may well pause before we precipitate the inconveniences of unsettling a long established and generally received classification, especially if our substitute only accentuates another set of distinctions of no greater absolute value than the former. Unless there is a decided preponderance of evidence in favor of the new, the old is entitled to prevail by right of priority and possession.

Professor Lesley's identification of the Bedford shale with the Old Red Sandstone, and Cleveland shale with Oil Sands and Chemung, thus dividing the Cuyahoga group in the middle and giving its two lower members to the Devonian, seems to me to lack sufficient grounds to justify it. In his note on the "Comparative Geology of Northern Ohio, Northwestern Pennsylvania, and Western New York" (2d Geological Survey of Pa., 1874, i,) where this opinion is announced, no distinct line of argument in its behalf is indicated. The local red color of the Bedford is of such small significance that I cannot believe that had any weight in the mind of so experienced a geologist. The Cuyahoga, Berea, Bedford and Cleveland, including the few feet of limestone under the latter, constitute a compact and natural group, holding substantially the same fauna throughout. I hope to show this more in detail in a subsequent paper on the vertical distribution of the fossils of this group. Then again, the fossils of the Cleveland shale, at the bottom of the series, are of decidedly Carboniferous types. These facts constitute a sufficient reason for retaining the Cuyahoga sub-group in the Carboniferous, whatever may be done with the rest of the Waverly.

ART. XXIII.-On some Primordial Fossils from Southeastern Newfoundland; by J. F. WHITEAVES, Paleontologist to the Geological Survey of Canada.

DURING the summer of 1874, Mr. T. C. Weston, of the Canadian Geological corps, spent a few days in collecting Primordial fossils from the shores and neighborhood of St. Mary's, Trinity and Conception Bays, Newfoundland, on behalf of Mr. A. Murray, Director of the Geological Survey of that Island. Most of the specimens obtained have been described and figured by Mr. Billings in the first part of the second volume of his "Palæozoic Fossils" of Canada, but a few remain of which no account has yet been published and which appear to be of sufficient interest to deserve a short notice.

The majority are from the banks of Manuel's Brook, a small stream which is not indicated in most maps of the island, but which runs into Conception Bay, on its eastern side, not far from Topsail Head. In Mr. Murray's Report of the Geological Survey of Newfoundland for 1868, the following paragraphs occur. "On Manuel's Brook a very coarse conglomerate may be seen, in strong and moderately regular beds, resting directly upon the syenitic gneiss of the valley above, dipping to the north at an angle of 15°, and forming a picturesque fall about one hundred and fifty yards below the bridge on the Bay Road." (p. 23.) "About four hundred yards below the bridge the conglomerate is overlaid conformably by a set of dark brown or blackish shales, with a very fine lamination coinciding with the bedding, which, with some hard calcareous beds interstratified, hold the banks of the brook until within a short distance of its exit into the Bay." (p. 24.) In the same report the thickness of these conglomerates is estimated at fifty feet and that of the shales at two hundred and fifty. (p. 27.) Sir W. E. Logan, in 1866, expressed the opinion that the slates of St. John, Newfoundland, probably belong to the same horizon as the Acadian or St. John's Group of St. John, N. B., and although little or no paleontological evidence of a satisfactory character had been obtained on the point, it has been supposed by Mr. Murray and others, that the shales of Manuel's River are of similar age. The correctness of the latter view is however fully borne out by the fossils collected by Mr. Weston, which are as follows.

1. Agnostus Acadicus Hartt. Not unfrequent, but usually a little larger than the types from St. John, N. B.

2. Agnostus (sp. undt.). A single head, apparently distinct from the preceding and perhaps new.

3. Microdiscus punctatus Salter. Abundant. This interesting species, which was originally described from the Lower Lingula Flags of South Wales, and which Mr. Salter thought might be "the fry of some larger trilobite," was first detected in the Primordial slates of St. John, N. B., by the late Mr. E. Billings. It has since been observed in rocks of the same age on the Kennebecasis River, N. B., where it was collected by Mr. G. F. Matthew. M. punctatus is said to have an "enormous nuchal spine," but, judging by Mr. Salter's figures, there is no spinous process on either of the postero-lateral angles of the head; the number of rings on the axis of the tail also is stated to be seven.

4. Microdiscus Dawsoni Hartt. One perfect and well preserved head. Very similar in sculpture to the preceding. The two forms occur together in the same pieces of rock from Newfoundland and New Brunswick and are very likely only different states of preservation of the same species. According to

Mr. Hartt the posterior angles of the cephalic shield of M. Dawsoni bear backward projecting spines," the glabella is described as "conical and pointed behind" but not spinous, and the middle lobe or axis of the tail as divided into six segments. The figure of the head of this trilobite, in the "Acadian Geology," is defective and does not show the lateral spines.

5. Conocephalites tener Hartt. Two heads of this easily recognized and well characterized form.

6. Conocephalites Baileyi Hartt. A single head, with an unusually small glabella.

7. Conocephalites Orestes? Hartt. Abundant, but badly preserved and hence the doubt as to the correct identification of the species. The facial sutures of Nos. 5, 6 and 7 being unknown their generic position is of course uncertain.

8. Paradoxides (sp. undt.). Fragments only.

Nos. 1, 3, 4, 5, 6 and possibly 7 are common to the Primordial slates of St. John, N. B., and to the shales of Manuel's Brook.

The shales of Kelly's Island, in Conception Bay, hold quantities of a small Lingula which appears to be undescribed and which may be briefly characterized thus:

Lingula Billingsiana, n. sp. Shell small, very slightly convex, compressed at the sides: outline elliptic ovate, narrowest behind length nearly twice the width: margin of the valves widening convexly and gradually from the beaks to the center, or a little beyond it: front narrowly and evenly rounded. Surface marked by fine concentric striations and faint radiating lines. Internal markings unknown. Length, about two lines and a half: width one line and a half.

This little shell, which may be the young of some larger species, is somewhat similar in shape and size to the Lingula minima of Sowerby, from the Upper Ludlow rocks of Great Britain. The two shells, however, belong to very different geological horizons, and besides this, L. Billingsiana is much narrower posteriorly than L. minima and not nearly so square in front. From Mr. Murray's report already quoted it would appear that the shales of Kelly's Island are not quite so old as those of Manuel's Brook, but that they are older than the Menevian sandstones of Great Bell Island.

ART. XXIV.-The Solar Eclipse of July 29th, 1878; by
Professor HENRY DRAPER, M.D.

As I have recently been giving attention to the subject of solar spectroscopy in consequence of my discovery of oxygen in the sun, it seemed to be desirable to take advantage of the total eclipse of July 29th, to gain as precise an idea as possible of the nature of the corona, because the study of that envelope has been regarded as impossible at other times. The main point to ascertain was whether the corona was an incandescent gas shining by its own light, or whether it shone by reflected sunlight. For this purpose I organized an expedition, and was fortunate enough to secure the coöperation of my friends Professors Barker and Morton and Mr. Edison. The scheme of operations was as follows: 1st, the photographic and photo-spectroscopic work as well as the eye slitless spectroscope were to be in charge of my wife and myself; 2d, the analyzing slit spectroscope was in charge of Professor Barker, with the especial object of ascertaining the presence of bright lines or else of dark Fraunhofer lines in the corona; 3d, the polariscopic examinations were confided to Professor Morton, who was also to spend a few moments in looking for bright or dark lines with a hand spectroscope; 4th, Mr. Edison carried with him one of his newly invented tasimeters with the batteries, resistance coils, Thomson's galvanometer, etc., required to determine whether the heat of the corona could be measured.

This entire programme was successfully carried out and good fortune attended us in every particular. The results obtained were: 1st, the spectrum of the corona was photographed and shown to be of the same character as that of the sun and not due to a special incandescent gas; 2d, a fine photograph of the corona was obtained, extending, in some parts, to a height of more than twenty minutes of arc, that is, more than 500,000 miles; 3d, the Fraunhofer dark lines were observed by both Professors Barker and Morton in the corona; 4th, the polarization was shown by Professor Morton to be such as would answer to reflected solar light; 5th, Mr. Edison found that the heat of the corona was sufficient to send the index beam of light entirely off the scale of the galvanometer. Some negative results were also reached, the principal one being that the 1474K, or so-called corona line, was either very faint or else not present at all in the upper part of the corona, because it could not be observed with a slitless spectroscope and the slit spectroscope only showed it close to the sun.

The general conclusion that follows from these results, is, that on this occasion we have ascertained the true nature of the

corona, viz: it shines by light reflected from the sun by a cloud of meteors surrounding that luminary, and that on former occasions it has been infiltrated with materials thrown up from the chromosphere, notably with the 1474 matter and hydrogen. As the chromosphere is now quiescent this infiltration has taken place to a scarcely perceptible degree recently. This explanation of the nature of the corona reconciles itself so well with many facts that have been difficult to explain, such as the low pressure at the surface of the sun, that it gains thereby additional strength.

The station occupied by my temporary observatory was Rawlins (latitude 41° 48′ 50′′, longitude 2h 0m 44 W. of Washington, height 6732 feet above the sea) on the line of the Union Pacific railroad, because, while it was near the central line of totality, it had also the advantages of being supplied with water from the granite of Cherokee Mountain and of having a repair shop where mechanical work could be done. I knew by former experience that the air there was dry and apt to be cloudless; in this particular our anticipations were more than fulfilled by the event, for the day of totality was almost without a cloud and the dew-point was more than 34° F. below the temperature.

The instruments we took with us were as follows and weighed altogether almost a ton. 1st. An equatorial mounting with spring governor driving clock, loaned by Professor Pickering, Director of Harvard Observatory. 2d. A telescope of five and a quarter inches aperture and seventy-eight inches focal length, furnished with a lens specially corrected for photography, by Alvan Clark & Sons. 3d. A quadruple achromatic objective of six inches aperture and twenty-one inches focal length, loaned by Messrs. E. and H. T. Anthony, of New York; to this lens was attached a Rutherfurd diffraction grating nearly two inches square, ruled on speculum metal. The arrangement, with its plate holders, etc., will be designated as a phototelespectroscope. 4th. A four-inch achromatic telescope with Merz direct vision spectroscope, brought by Professor Barker, from the collection of the University of Pennsylvania. 5tb. A four-inch achromatic telescope, also brought by Professor Barker; to it was attached Edison's tasimeter. Besides these there were polariscopes, a grating spectroscope, an eye slitless spectroscope with two-inch telescope, and, finally, a full set of chemicals for Anthony's lightning collodion process, which in my experience is fully three times quicker than any other process.

The arrangement of the photo-telespectroscope requires farther description, for success in the work it was intended to do, viz., photographing the diffraction spectrum of the corona, was difficult and in the opinion of many of my friends impossible.