3. Mr. Bradley's new specimens also show that there are three pairs of glabellar furrows, the anterior being represented by two small indentations just in advance of the points where the ocular ridges reach the glabella; and further that the course of the facial suture is the same as it is in C. striatus, (Emerich). The pygidium is more obtusely rounded than is represented in our Figure 2.

As to the correctness of the generic reference of this species it may be remarked that Barrande is of opinion that no less than eleven of those which Angelin has figured under the genera Solenopleura, Eryx, Conocoryphe and Harpides should be placed in Conocephalites. In this view of Barrande's, Angelin has concurred. The genus has thus been greatly extended and judg ing from the form of the head (and more particularly of the glabella) of Angelin's species C. brachymetopus, C. homelotopus and C. canaliculatus I think we are perfectly justified in referring this species to Conocephalites. The genus is most closely allied to Calymene, having the same number of segments in the thorax -the same number and arrangement of pieces in the head and the same general form and lobation of the glabella, the differences between the genera consisting principally in certain characters of the pleuræ and hypostomat to which may be added the ocular ridge which although not a constant character in Conocephalites may be regarded as of some generic value as it does not occur at all in Calymene. I would also state that since examining Mr. Bradley's recent collection, have been strongly impressed by the resemblance between the form of the cheek and small needle-shaped posterior spines of C. minutus and the same parts of the head of the Quebec species which I have called Menocephalus globosus, and it appears to me that Menocephalus must be regarded as another closely allied genus. If we except those two genera, Calymene and Menocephalus, there is no other but Conocephalites to which our new trilobite bears any near affinity.

*See Barrande's "Paralléle entre les dépôts Siluriens de Bohême et de Scandinamie, p. 19; and compare the tables on p. 17 and 35 of the same work. See also Angelin's Paleontologia Scandinavica.

+ See Barrande, “ Systême Silurien du centre de la Bohême,” p. 417–419. Montreal, 20th Sept., 1860.

ART. XXXI.-The Great Auroral Exhibition of Aug. 28th to Sept. 4th, 1859.-6TH ARTICLE; by Prof. ELIAS LOOMIS.

SINCE our last Auroral article was prepared for the press, the following letter has been received from the Secretary of the Smithsonian Institution.

Washington, June 6th, 1860.

Dear Sir-Some time since, you wrote us in regard to the aurora of September, 1859, and I now write to inform you that we have a very large collection of materials in regard to this interesting meteor which in justice to the writers ought to be published. It is, however, a pity that the data for scientific deductions in regard to this interesting phenomenon should be scattered, and we will therefore present the whole to Silliman's Journal, provided the Editors will publish it. Will you take charge of it, and prepare it for the press?

JOSEPH HENRY, Secretary S. I.

The editors of this Journal have accepted the liberal proposition of Prof. Henry, so far as to publish whatever might be supposed to be of importance in an investigation of the theory of the Aurora. A considerable portion of the materials collected by the Smithsonian Institution have already appeared in former numbers of this Journal, and many of the reports are from neighboring stations where the Auroral appearances are almost identically the same. From the entire mass of materials we have aimed to select those Reports only which were the most complete and elaborate, and which were so distributed in geographical position as to afford a correct idea of the appearances throughout

the entire area of the United States.

OBSERVATIONS OF THE AURORA OF AUGUST 28TH, 1859.
Selected from the Smithsonian Papers.

1. Observations at Burlington, Minnesota, (lat. 47° 1', long. 92° 30'), by A. A. HIBBARD.

The aurora of Aug. 28th, commenced at 8 P. M., and increased very rapidly until 8 P. M., when it came to a centre directly over our heads. It went about three-fourths the circumference of the horizon at the base, and completely round at the top, and down about one-third on the south side. Stars very bright and light enough to read very fine print. At 9 P. M. it had nearly disappeared over head; and but few beams to be seen in any part of the horizon, although new beams were forming in the north. At 9 P. M. the beams were very light, and somewhat scattered. At 10 P. M. it had entirely disappeared.

2. Observations at Marquette, Michigan, (lat. 46° 32', long. 87° 41′), by Dr. G. H. BLAKER

Aug. 28th, at 8 P. M., a bright crown overhead, with beams or streamers extending to every point of the compass, but soon lost in a white haze. In the course of an hour these streamers extended to the horizon in every direction, with bright streams of white light shooting up towards the crown, all of which became perfectly red, or of a bright crimson color over head. This continued to increase in brightness until after midnight, with floods of white light at the horizon, all passing into crimson fleecy vapor in the zenith.

3. Observations at Winona, Minnesota, (lat. 44° 3', long. 91° 36′), by T. F. THICKStun.

Aug. 28th, an auroral bank and a few pencilled streamers had formed at 9 P. M. At midnight the streamers and corona filled the whole heavens except the N. E. portion. During the whole night the light was equal to that of a half moon.

4. Observations at Green Bay, Wisconsin, (lat. 44° 30′, long. 87° 56′), by D. Underwood.

Aug. 28th, about 7 P. M., the aurora was visible in the northern part of the heavens, but did not attract particular notice until about 9 P. M. Soon after eight the sky began to redden, and became nearly of a blood-red color. Soon the streaks were observed shooting upward from all points of the horizon, and concentrating in a large luminous mass in mid-heavens. The greatest intensity of color was at the zenith. Rays were constantly shooting up from all points of the horizon and the colors constantly changing. The rays emitted an intense red light for about half an hour, when they began slowly to fade away in the north and south, but in the east and west they continued to glow until 10 P. M., when they began to fade away. Flashes of white light appeared among them, commencing from the horizon and moving upwards, following each other in rapid succession like the waves of an immense sea of light. They grew brighter as the red color disappeared, and when this was wholly gone they also gradually faded away.

5. Observations at Milwaukee, Wisconsin, (lat. 43° 3', long. 87° 57'), by Prof. E. P. LARKIN.

Aug. 28th, at 8 P. M., an aurora commenced. About 8 P. M. an arch formed from S.W. by the north to the S.E., with dark broken clouds below. The streamers now commenced, principally in the N.W. and N.E., and were surprisingly beautiful, of crimson, purple, peach and orange; the crimson predominating. At 8h 45m a perfect corona formed a few degrees south of the zenith.

At 9 P. M. the aurora began to fade, and at ten had nearly disappeared. At 10 P. M. the north gave indications of another aurora which occurred about 12 o'clock, nearly equal in splendor to the first, and still another occurred about 3 A. M. There were also auroras late in the night of the 30th and also of the 31st.

6. Observations at Burlington, Wisconsin, (lat. 42° 39', long. 87° 44′), by D. MATHEWS.

Aug. 28th, at 8 P. M., the appearance was that of a large luminous ring surrounding the zenith; but this form was very transient, the light becoming concentrated in the west. Between 8 and 9 P. M. there were two arches formed in the north, the first almost 30° in altitude, and the second about 40°. From the outer edge of the larger arch darted a succession of streamers or rays of light. At 8h 15m a perfect flood of light came up in the east, not in streams, but like the dawn of day, just before sunrise. This appearance lasted about half an hour. At 9 P. M. streams of light radiated in every direction from a point about ten degrees south of the zenith, covering the whole heavens except a space in the south. One broad belt of red light extended from near the zenith to the horizon at a point a little north of

west.

7. Observations at Dubuque, Iowa, (lat. 42° 30', long. 90° 52′), by Asa HORR, M.D.

Aug. 28th, the aurora began with floating irregular masses of auroral clouds in the north, which soon spread over the sky, terminating in a broad zone of light spanning the heavens from E. to W. and reaching to 20° south of the zenith. At 8 P. M. many of the luminous clouds became distinctly crimson, with the deepest hue near the horizon. At 8h 15m a distinct arch formed in the north crowned with tall flickering white streamers. The crimson clouds now dissolved into paler streamers; at 8h 35m the streamers subsided; and at 8h 40m the red clouds near the horizon and the diffuse light in the north appeared again. From this time till 9 P. M. a crimson shade was spread over the whole of the broad belt, with varying hue and brightness. The arch in the north formed again with whitish streamers which remained moderately bright until 11 P. M.

8. Observations at Waltham, Massachusetts, (lat. 42° 24', long. 71° 14′), by Rev. THOMAS HILL.

Aug. 28th, at 7 P. M., there were visible some splendid masses of rose-colored light in the east and west near the horizon; that in the west being nearly obscured by twilight. At 7h 45m a well defined arch passed south of the zenith, and all the sky north of it was filled with light, radiating toward the pole of the

dipping needle. I watched the aurora from 9 to 10 P. M., and at 3 A. M. got up again to look. It was then very brilliant and rosy all along the southern horizon.

9. Observations at Monroe, Michigan, (lat. 41° 56', long. 83° 22′), by Miss HELEN J. WHELPLEY.

Aug. 28th, about 8 P. M., there was a broad line of intensely yellow light extending from east to west. In a few moments the whole sky to within 20° of the south, seemed to be permeated with a clear whitish light; yellowish rays constantly shooting up from the east, north and west horizon to the zenith. At the same time appeared a bright rose colored mass in the east, which gradually enlarged until it covered nearly threefourths of the heavens, and about 9 P. M. the rays met and formed a perfect corona a little south of the zenith.

10. Observations at Willow Creek, Illinois, (lat. 41° 45', long. 88° 56′), by E. E. BACON.

Aug. 28th-aurora first seen at 8 P. M., corona and beams at 8h 40m, arch 8h 45m. Beams of red very brilliant in the east and west, and at the corona from 8h 35m to 8h 55m. At 9h the beams and corona had disappeared, and a broad red belt extended across the heavens, passing over to the south. Two distinct arches were formed in the north. At 9h 15m bright beams in the southeast, the red belt disappearing in the east. At 9b 25m redness nearly gone. At 9h 28m arches broken. At 9h 35m brilliant spot in N.E. At 9h 40m arch reformed, but not so brilliant. At 12h 30m beams with far greater grandeur than at 8h 40m. Beams streamed from all round the horizon to the zenith. the southern half of the sky, the beams flashed like the blaze of a great fire. At 12h 45m a bright belt from E. to W., in the south, with a dark belt something like a cloud under it. At 1h 12m bright belt in the south gone. Aurora lasted till daylight. 11. Observations at Sandwich, Illinois, (lat. 41° 31', long. 88° 30'), by Dr. N. E. BALLOU.

In

Aug. 28th, at 7 P. M., there was a bright luminous band, a degree in width, spanning the heavens. Soon it became tortuous; and in the zenith it pointed southward half way to the horizon. At 8 P. M. red gleams shot up in the N.W. directly to the zenith. At 8 P. M. the same appearance sprung up in the N.E. At 9 P. M. the entire northern half of the sky was brilliantly red, with gleams which soon culminated in a corona. At 9 P. M. the whole was tinged with red, alternating with beams of light. At 10 P. M. the red tinge floated away to the south. At midnight it presented much the same appearance as before.